ALBERT

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Hiral D. Shah, J.A. Bhalodia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this communication, we report the structural and electrical transport properties of (1-〈em〉x〈/em〉) La〈sub〉0.7〈/sub〉Sr〈sub〉0.3〈/sub〉Mn〈sub〉0.95〈/sub〉Co〈sub〉0.05〈/sub〉O〈sub〉3〈/sub〉 (LSMCO) + (〈em〉x〈/em〉) ZnO (〈em〉x〈/em〉 = 0%, 6%, 9%, 12%, 15% & 18%) composites. For the preparation of (1-〈em〉x〈/em〉) LSMCO + (〈em〉x〈/em〉) ZnO (〈em〉x〈/em〉 = 6%, 9%, 12%, 15% & 18%) composites, sample of LSMCO was prepared by the auto combustion technique/inexpensive modified sol-gel technique. The results of Rietveld refined XRD data show that LSMCO sample possesses a rhombohedral structure with the 〈em〉R-3c〈/em〉 space group whereas ZnO compound remains with hexagonal structure with the 〈em〉P6〈/em〉〈sub〉〈em〉3〈/em〉〈/sub〉〈em〉mc〈/em〉 space group in all the composite samples. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that no any extra unwanted phase was observed in each composite excluding the LSMCO and ZnO phases. ZnO is mostly distributed at the grain boundaries and on the surface of the LSMCO grains. Elemental presence and ratio was confirmed through the EDX analysis. The electrical resistivity of LSMCO and each composite was measured in the temperature range of 2 K–320 K at 0 Oe, 10 kOe, 50 kOe & 90 kOe magnetic field. The results indicate that the ZnO addition increases the resistivity of all the composites compare to that of pure LSMCO. The electrical resistivity explored by the theoretical model below 〈em〉T〈/em〉〈sub〉MI〈/sub〉 and fitting enlightenment for the observed behavior is transmitted here in detail.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Dezhi Yang, Weihua Liu, Dingfu Cheng, Jieshi Chen, Hao Lu, Chun Yu, Jijin Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉(Co, Cr)23C6 type carbide is a typical metallic compound in many cobalt bearing alloys, and it acts as the strengthening phase in the form of bulk eutectic carbides or precipitated carbides. In this work, first-principles calculations were carried out to investigate the electronic structure, phase stability, mechanical and magnetic properties of (Co, Cr)23C6 with different cobalt occupation. Some of the calculated values are compared with previous studies and, they are found to be in a good agreement. The method considering curvature radius is firstly used to describe the degree of anisotropy. The hardness calculated through elastic constants presents an approximate downtrend with the cobalt concentration. Analysis of the density of states (DOS), overlapped population and electron density maps, indicates that the bonds in (Co, Cr)23C6 are the mixture of covalent, ionic and metallic bonds, the interactions of 〈em〉d-d〈/em〉 orbits between metallic atoms contribute most to the hybridization mode. According to the population analysis, the reduction in hardness can attribute to the increase of metallicity and iconicity of the interacted metallic atoms. In addition, the formation of a large quantity of antibonding also plays a negative role in intrinsic hardness of (Co, Cr)23C6 when massive substitution of cobalt atom.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Morteza Alizadeh, Andisheh Shakery, Erfan Salahinejad〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this research, the structure and mechanical properties of 1050 aluminum strips reinforced with E-glass fibers, processed by the cross accumulative roll bonding (CARB) process, were investigated from microscopic, hardness, tensile and peeling viewpoints. The results indicated that the incorporation of the glass fibers in the Al matrix increases strength and micro-hardness but decreases elongation. In addition, it was realized that some of these fibers are broken and changed to short fibers during the CARB process. The presence of the glass fibers strongly also reduces the bond efficiency of the Al strips, typically from 50% to 5%. To compensate this deleterious effect, it was found that at least 25% should be increased to the normal thickness reduction used in CRAB.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): J.Y. Oh, Tien M. Le, A.T. Pham, D.H. Tran, D.S. Yang, B. Kang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we investigated a correlation between superconductivity and interlayer coupling of two different alkaline (Na and K)-substituted Bi〈sub〉1·6〈/sub〉Pb〈sub〉0·4〈/sub〉Sr〈sub〉2〈/sub〉Ca〈sub〉2〈/sub〉Cu〈sub〉3〈/sub〉O〈sub〉10+δ〈/sub〉 (BSCCO) polycrystalline samples. The excess conductivity analysis by the Aslamazov-Larkin (AL) and Lawrence-Doniach (LD) theories showed that Na substitution at the Ca site induced a gradual broadening of 3D fluctuation region with increasing interlayer coupling strength, which explains a systematic increase of 〈em〉T〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉 and a decrease of normal state resistivity. On the other hand, exactly the opposite results were observed in the K-substituted samples in place of Sr. Extended x-ray absorption fine structure (EXAFS) studies revealed that substitution of Na and K generated completely different effects on the local structure around Cu atoms. It is noticeable that the Cu–O bond distance was found to decrease monotonically with the varying amounts of Na, which indicates that the CuO〈sub〉2〈/sub〉 layer is stabilized. On the while, the opposite was observed to occur with the varying amounts of K. Unlike the Cu–Ca bond which was the least affected by the substitution, the Cu–Sr bond distance increased drastically with K substitution. All these findings indicate that Na substitution at the Ca site enhances superconductivity with no loss of interlayer interaction, while K substitution at the Sr site weakens superconductivity due to the diminished interlayer interaction.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Moara M. Castro, Shima Sabbaghianrad, Pedro Henrique R. Pereira, Eric M. Mazzer, Augusta Isaac, Terence G. Langdon, Roberto B. Figueiredo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A magnesium/aluminium composite was produced by room temperature consolidation through high-pressure torsion (HPT) processing. Half-discs of the pure metals were placed side-by-side and subjected to different numbers of turns. The initially reduced interface between the phases gradually increased with increasing rotation. The composite displayed a significant ductility even after 10 turns. The distribution of hardness in the HPT-processed discs was bi-modal in the early stages of processing. As the number of turns increased and the thickness of the phases decreased there was a noticeable increase in hardness. The hardness values of the composite further increased after thermal treatment due to the formation of intermetallics within the interface between the magnesium and aluminium-rich phases.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Lipeng Xu, Fei Zhou, Jizhou Kong, Haobin Zhou, Qian Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effects of testing temperature on the electrochemical properties of Li(Ni〈sub〉0.6〈/sub〉Mn〈sub〉0.2〈/sub〉Co〈sub〉0.2〈/sub〉)O〈sub〉2〈/sub〉 are investigated in detail. When the testing temperature is 40 °C, the Li(Ni〈sub〉0.6〈/sub〉Mn〈sub〉0.2〈/sub〉Co〈sub〉0.2〈/sub〉)O〈sub〉2〈/sub〉 cathode material possesses the highest initial discharge capacity of 162.4 mAh·g〈sup〉−1〈/sup〉 at 0.5C rate, but their cycling stability decreases markedly. When the test temperature rises up to 60 °C, the side reaction between electrolyte and cathode material becomes serious, and the Li(Ni〈sub〉0.6〈/sub〉Mn〈sub〉0.2〈/sub〉Co〈sub〉0.2〈/sub〉)O〈sub〉2〈/sub〉 cannot work. When the testing temperature decreases, the electrochemical impedances like R〈sub〉ct〈/sub〉 values increase, and then the discharge capacity at 0 °C, −10 °C and −20 °C is only 80%, 53% and 23% of that at 25 °C. Based on the electrochemical impedance spectra at different temperatures, four kinds of equivalent circuit models are classified. The cycle and rate performance of Li(Ni〈sub〉0.6〈/sub〉Mn〈sub〉0.2〈/sub〉Co〈sub〉0.2〈/sub〉)O〈sub〉2〈/sub〉 cathode material could be improved obviously through Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉(OH)〈sub〉2〈/sub〉 modification in an extreme environment, and especially in sub-zero environment.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Kenji Yoshii, Naoshi Ikeda〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dielectric and magnetocaloric measurements are carried out for the chromite TmCrO〈sub〉3〈/sub〉. This oxide was reported to be multiferroic below the Néel temperature (〈em〉T〈/em〉〈sub〉N〈/sub〉) of ∼125 K, likely due to a structural transformation. The dielectric response shows large dielectric constants below 300 K. However, from the analyses of loss tangent, AC conductivity and dielectric modulus, this behavior is rooted in hopping of charge carriers rather than electric dipoles, as proposed for some other chromites. No dielectric anomaly is found at 〈em〉T〈/em〉〈sub〉N〈/sub〉. The magnetocaloric effect shows that the magnetic transitions at 〈em〉T〈/em〉〈sub〉N〈/sub〉 as well as the spin reorientation temperature are of a second order. This result strongly suggests the absence of magnetostructural transition at 〈em〉T〈/em〉〈sub〉N〈/sub〉 in accord with no observation of ferroelectric transition at this temperature.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Rattiya Hongtong, Panya Thanwisai, Rattakarn Yensano, Jeffrey Nash, Sutham Srilomsak, Nonglak Meethong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Core-shell olivine-type electrospun and doped LiFePO〈sub〉4〈/sub〉/FeS/C composite fibers were synthesized via a single-step process employing an electrospinning method using LiOH·H〈sub〉2〈/sub〉O, metal sul phates, H〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉, citric acid, and polyvinylpyrrolidone (PVP) as the starting materials. Electron microscopy studies showed that the mean diameter of the core-shell composite fibers was about 280 ± 20 nm with a LiFePO〈sub〉4〈/sub〉 phase forming a core with a diameter of about 100 ± 20 nm and a carbon shell with a thickness of 80 ± 20 nm. An FeS phase was formed by a direct reduction of iron (II) sulfate (FeSO〈sub〉4〈/sub〉) that was evenly distributed within the core region of the composite fibers and further improved the electronic conductivity of the fibers. Na〈sup〉1+〈/sup〉, Mg〈sup〉2+〈/sup〉, and Al〈sup〉3+〈/sup〉 doping ions affected fiber morphology and electrochemical performance. All composite fibers showed excellent electrochemical performance. However, Al〈sup〉3+〈/sup〉 ions improved the electrochemical performance of the composite fibers to a significantly greater degree than Na〈sup〉1+〈/sup〉 and Mg〈sup〉2+〈/sup〉 doping ions, increasing the electronic and ionic conductivities of the material while maintaining their core-shell composite fiber characteristics.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Electrospun LiFePO〈sub〉4〈/sub〉/FeS/C and 5% doped 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈mi〉L〈/mi〉〈mi〉i〈/mi〉〈mi〉F〈/mi〉〈msubsup〉〈mrow〉〈mi〉e〈/mi〉〈/mrow〉〈mrow〉〈mn〉1〈/mn〉〈mo linebreak="badbreak"〉−〈/mo〉〈mrow〉〈mo stretchy="false"〉(〈/mo〉〈mi〉n〈/mi〉〈mi〉x〈/mi〉〈mo linebreak="badbreak"〉/〈/mo〉〈mn〉2〈/mn〉〈mo stretchy="false"〉)〈/mo〉〈/mrow〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈mo linebreak="badbreak"〉+〈/mo〉〈/mrow〉〈/msubsup〉〈msubsup〉〈mrow〉〈mi〉M〈/mi〉〈/mrow〉〈mrow〉〈mi〉x〈/mi〉〈/mrow〉〈mrow〉〈mi〉n〈/mi〉〈mo linebreak="badbreak"〉+〈/mo〉〈/mrow〉〈/msubsup〉〈mi〉P〈/mi〉〈msub〉〈mrow〉〈mi〉O〈/mi〉〈/mrow〉〈mrow〉〈mn〉4〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉/FeS/C (M = Na〈sup〉1+〈/sup〉, Mg〈sup〉2+〈/sup〉, Al〈sup〉3+〈/sup〉) composites with a unique core-shell structure were synthesized via a simple single-step process to improved electrochemical properties for high performance and low cost Li-ion batteries.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324946-fx1.jpg" width="287" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): L.V.B. Diop, O. Isnard〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effects of Fe substitution on the structural and magnetic properties of the HoCo〈sub〉12-〈em〉x〈/em〉〈/sub〉Fe〈sub〉〈em〉x〈/em〉〈/sub〉B〈sub〉6〈/sub〉 (0 ≤ 〈em〉x〈/em〉 ≤ 2) series of intermetallic compounds have been studied. All of the compounds form in the rhombohedral SrNi〈sub〉12〈/sub〉B〈sub〉6〈/sub〉-type structure, the lattice constants increasing linearly with 〈em〉x〈/em〉. These compounds are ferrimagnets with a small transition metal magnetic moment and exhibit a spin reorientation transition. The Curie temperature decreases from 147 K for 〈em〉x〈/em〉 = 0–105 K for 〈em〉x〈/em〉 = 2. The Fe for Co substitution leads also to a progressive decrease of the spontaneous magnetization. The spin reorientation transition temperature is significantly reduced upon Fe for Co substitution whereas the compensation temperature is much less sensitive to the Fe composition.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Maxim S. Likhanov, Vladislav O. Zhupanov, Valeriy Yu Verchenko, Andrei A. Gippius, Sergei V. Zhurenko, Alexey V. Tkachev, Dina I. Fazlizhanova, David Berthebaud, Andrei V. Shevelkov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a new Fe〈sub〉1–〈em〉x〈/em〉〈/sub〉Re〈sub〉〈em〉x〈/em〉〈/sub〉Ga〈sub〉3〈/sub〉 solid solution, in which a 5〈em〉d〈/em〉-metal––rhenium––partially substitutes for iron to the limiting composition of 〈em〉x〈/em〉 = 0.10. The crystal structure refined for the composition Fe〈sub〉0.91〈/sub〉Re〈sub〉0.09〈/sub〉Ga〈sub〉3〈/sub〉 shows the expected increase in the unit cell parameters compared to the parent FeGa〈sub〉3〈/sub〉 compound, however the M–M (M = Fe, Re) distance decreases within the M–M dumbbell, indicating an increased M–M bonding density. Therein, investigation of the local structure by means of 〈sup〉69,71〈/sup〉Ga NQR spectroscopy revealed the formation of homonuclear Fe–Fe and Re–Re dumbbells. Transport and thermoelectric properties have been investigated for the Re-substituted FeGa〈sub〉3〈/sub〉. Electrical transport measurements showed preservation of the nonmetallic conductivity of Fe〈sub〉1–〈em〉x〈/em〉〈/sub〉Re〈sub〉〈em〉x〈/em〉〈/sub〉Ga〈sub〉3〈/sub〉 despite the decrease of the valence electron concentration from 17 to 16.9 electrons per formula. At low temperatures, Fe〈sub〉1–〈em〉x〈/em〉〈/sub〉Re〈sub〉〈em〉x〈/em〉〈/sub〉Ga〈sub〉3〈/sub〉 is a 〈em〉p〈/em〉-type semiconductor with the band gap of 0.4 eV, but with increasing temperature the sign of the dominant charge carriers changes. Owing to the alloying effect, Fe〈sub〉1–〈em〉x〈/em〉〈/sub〉Re〈sub〉〈em〉x〈/em〉〈/sub〉Ga〈sub〉3〈/sub〉 displays 1.5 times lower thermal conductivity than FeGa〈sub〉3〈/sub〉, which increases at high temperatures because of the growing contribution of the electronic term.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819325198-fx1.jpg" width="454" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Jiashu Zhang, Weiyao Zhao, Zhenjie Feng, Jun-Yi Ge, Jincang Zhang, Shixun Cao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report the crystal growth, structure analysis and magnetic phase transitions in the single crystal Sm〈sub〉0.15〈/sub〉Dy〈sub〉0.85〈/sub〉FeO〈sub〉3〈/sub〉. The high-quality of the crystal is verified by X-ray diffraction technique. Our research reveals that: 1) the iron sublattice spin reorientation (SR) transition emerges at 25 K, and ends at 10 K; 2) the rare earth antiferromagnetic (AF) order transition happens at 2.6 K; 3) there is a special wasp-waist hysteresis loop at low temperatures. Knowledge of such phase transitions in rare earth orthoferrite system is of potential importance for applications and theoretical studies.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Yuliang Jiang, Xueyan Fu, Zidong Zhang, Wei Du, Peitao Xie, Chuanbing Cheng, Runhua Fan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Carbon nanofibers embedded with magnetic Fe〈sub〉3〈/sub〉C nanoparticles have been synthesized using electrospinning technique, followed by one-step carbonization. By using Fe〈sub〉3〈/sub〉C/C nanofibers as filler with 10% content, the sample can achieve a minimum reflection loss (RL) of −54.94 dB with a thickness of 1.36 mm, as well as the broad effective absorption bandwidth (EAB) can reach to 4.5 GHz (13.3–17.8 GHz) at the thickness of 1.55 mm. The superior properties might be due to the synergistic effects of dielectric loss, magnetic loss, multiple scattering and reflection. This work presents a facile and promising method to produce high performance microwave absorption materials with thin thickness, light weight and strong absorption.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): E.J. Pickering, K.A. Christofidou, H.J. Stone, N.G. Jones〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to reduce the environmental impact of air travel, it is desirable that the efficiencies of gas turbine engines are increased. One way to achieve this goal is to increase the operating temperatures of the engine cores. Unfortunately for aero-engine manufacturers, the temperature capability limits of the Ni-base superalloys used currently have been reached. Hence, new alloys need to be developed that are capable of operating at significantly higher temperatures. In this article, the potential of tantalum-base superalloys is discussed and explored. A suite of alloys based on the Ta-Al-Co system was investigated. It was found that an array of fine carbide precipitates was formed in the Ta-rich matrix in a subset of the alloys, which is promising in terms of developing a strong and damage-tolerant microstructure, but that the elemental partitioning of Al out of the matrix accompanying precipitation is likely to degrade environmental resistance. Nevertheless, it is believed that the design principles described have the potential to facilitate the development of the next generation of high-temperature alloys based on systems of this type.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): C.Q. Zhou, Q.A. Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to understand the effect of Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 nanoparticles on crystallite growth kinetics of nanocrystalline Mg, the crystallite growth characteristics in a Mg−Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 composite and a pure Mg sample were comparatively investigated in this work. The crystallite growth exponents of nanocrystalline Mg in the Mg−Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 composite and pure Mg were determined as 〈em〉n〈/em〉 = 5 and 〈em〉n〈/em〉 = 4, respectively. Meanwhile, the activation energy for crystallite growth in Mg−Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 composite was calculated to be 118.8 kJ/mol, which is higher than 97.1 kJ/mol in pure nanocrystalline Mg. Further studies reveal that the rise of crystallite growth exponent and increase of activation energy in the Mg−Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 composite are primarily attributed to the pinning effect of Pr〈sub〉3〈/sub〉Al〈sub〉11〈/sub〉 nanoparticles at crystallite boundaries of Mg.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Liming Tan, Yunping Li, Wenkai Deng, Yong Liu, Feng Liu, Yan Nie, Liang Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three Ni-base powder metallurgy superalloys have been developed recently, and tensile tests at temperatures ranging from room temperature (RT) to 815 °C were conducted on them. The results conformed their excellent tensile properties, in comparison with several other existed polycrystalline superalloys. In this work, by means of microstructure characterization, thermal dynamic calculations, and theoretical modeling, different strengthening mechanisms including precipitation strengthening, grain boundary strengthening, solid solution strengthening, and Orowan strengthening, were found to contribute to the yield strength in different degrees, which would help to further enhance the tensile properties of these alloys through composition design and processing optimization thereafter.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324892-fx1.jpg" width="459" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Gautam Kumar Sarma, Aslam Khan, Ahmed Mohamed El-Toni, Md. Harunar Rashid〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we report for the first time, the synthesis of CuO-Nd(OH)〈sub〉3〈/sub〉 nanocomposites via a co-precipitation method coupled with the hydrothermal aging process. Varying the pH of the reaction medium, the shape of the nanocomposites could be controlled which determines their surface areas. These CuO-Nd(OH)〈sub〉3〈/sub〉 nanocomposites exhibit very high adsorption capacity with successful removal of ∼ 97% of brilliant blue G (BBG) from water in 180 min under ambient condition. The adsorption process primarily follows Lagergren pseudo-first-order kinetics. The Langmuir isotherm model fits well with a very high monolayer adsorption capacity of 394.1 mg g〈sup〉−1〈/sup〉 at 30 °C. The mechanistic study supports chemisorption-type adsorption between the dye molecule and the adsorbent. Regeneration of the spent adsorbent makes the whole process cyclic and eco-friendly.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307915-ga1.jpg" width="297" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Junchao Zhao, Zhitao Yin, Muhammad Usman Shahid, Haoran Xing, Xudong Cheng, Yangyang Fu, Song Lu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The re-ignition of pool fires is a common hazard phenomenon in fire extinguishing. Dry chemicals with oleophobicity may solve this problem because powders can float on the oil surface and prevent evaporation of fuel pool. In this research, MAPP (modified ammonium polyphosphate) with superhydrophobicity, oleophobicity, and higher chemical activity is prepared which can quickly quench pool fires and provide longer protection. The activation indexes of MAPP for water, diesel, aviation kerosene and gasoline are 98.5%, 87.4%, 98.7% and 98.4%, respectively. Lower activation energy of MAPP means that it will show higher chemical activity in fire. The fire-extinguishing performance of MAPP is much higher than that of Commercial UDCA (ultra-fine dry chemical agent) during fire experiments. After extinguished by MAPP, the fuel pool is hard to be re-ignited. The significance of this study is to propose a new strategy for preventing the re-ignition of pool fires.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419305497-ga1.jpg" width="492" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): L. Sbardella, I. Velo-Gala, J. Comas, I. Rodríguez-Roda Layret, A. Fenu, W. Gernjak〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Ultraviolet radiation (UV)-activated peroxydisulfate (PDS) and peroxymonosulfate (PMS) advanced oxidation processes were examined for their capacity to remove nine pharmaceutically active compounds (PhACs) from secondary effluent. The effect of operational parameters (initial oxidant concentration, UV exposure time, pH, common coexisting anions and effluent organic matter (EfOM)) on UV/PDS and UV/PMS treatment efficiency was investigated in a collimated beam device housing a low-pressure mercury UV lamp emitting light at 253.7 nm.〈/p〉 〈p〉Both AOPs achieved high removals (〉90%) when applied to pure water. Under otherwise similar conditions the removal percentage fell by 20–30% due to the scavenging of effluent organic matter (EfOM) in secondary effluent. Finally, eliminating EfOM but maintaining the inorganic composition, the radical scavenging effect was reduced and 98.3% and 85.6% average removals were obtained by UV/PDS and UV/PMS, respectively.〈/p〉 〈p〉Increasing pH improved degradation of several PhACs containing amine groups. Higher oxidant dosages created only a significant benefit in UV/PDS. The chloride anion produced a negligible effect on both processes, while higher nitrate concentrations increased removal percentage but did not affect degradation rate constants. Finally and surprisingly, the addition of bicarbonate had the strongest positive impact on the degradation kinetics observed, even stronger than the elimination of EfOM from secondary effluent.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308222-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Chi Xu, Lirong Gao, Minghui Zheng, Lin Qiao, Lili Cui, Kunran Wang, Di Huang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) in commercial rubber track products and raw materials (rubber granules and adhesives) were investigated by two-dimensional gas chromatography with electron-capture negative-ionization mass spectrometry (GC × GC-ECNI-MS). The mean SCCP and MCCP concentrations in the rubber track products were 3.64 × 10〈sup〉3〈/sup〉 and 4.14 × 10〈sup〉4〈/sup〉 μg/g, respectively. The mean SCCP concentration in the products was significantly higher than those in the rubber granules (2.78 μg/g), but in the same order of magnitude as those in the adhesives (3.34 × 10〈sup〉3〈/sup〉 μg/g). The SCCP concentrations in almost half of the rubber track products and four fifths of the adhesives exceeded the limit (1.5 g/kg) set in Chinese standard GB 36246-2018. The dominant SCCP and MCCP congeners in the rubber track products were similar to those in the relevant adhesives but different from those in the paired granules. Principal component analysis and contribution calculations indicated that chlorinated paraffins (CPs) in adhesives could be the main sources of CPs in rubber track products. The high CP concentrations found in rubber track products are of special concern because of the relatively high exposures for children and negative effect on human health and environment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308076-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Christopher S. Daniel, Peter D. Honniball, Luke Bradley, Michael Preuss, João Quinta da Fonseca〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The properties and performance of Zr-2.5 Nb alloys are strongly influenced by their crystallographic texture. As in similar Ti alloys, the texture evolution during hot-processing depends on the complex interactions between the α and β phases and involves deformation, annealing and phase transformation. Although the effect of temperature and deformation has been studied for extruded tube in this alloy, there is no data for texture development during rolling. There is some rolling data for Ti-64 (Ti–6Al–4V), but it is usually for just one of the phases and for a limited set of temperatures. We carried out hot-rolling trials from 700 °C–900 °C to reductions of 50%, 75% and 87.5% and found that the texture in both phases strengthens sharply before the β-transus and when both phases are present in similar amounts. At this point, the texture in α is a strong 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈mn〉0002〈/mn〉〈mo〉|〈/mo〉〈mo〉|〈/mo〉〈mtext〉TD〈/mtext〉〈/mrow〉〈/math〉 and the texture in β a strong 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈mrow〉〈mo stretchy="true"〉{〈/mo〉〈mrow〉〈mn〉001〈/mn〉〈/mrow〉〈mo stretchy="true"〉}〈/mo〉〈/mrow〉〈mrow〉〈mo〉〈〈/mo〉〈mrow〉〈mn〉110〈/mn〉〈/mrow〉〈mo〉〉〈/mo〉〈/mrow〉〈/mrow〉〈/math〉 rotated cube component. The results suggest there might be a synergistic effect between the two components, which includes dynamic phase transformation. The texture evolution towards stable α 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.svg"〉〈mrow〉〈mrow〉〈mo stretchy="true"〉{〈/mo〉〈mrow〉〈mn〉11〈/mn〉〈mrow〉〈mover accent="true"〉〈mn〉2〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mo stretchy="true"〉}〈/mo〉〈/mrow〉〈mrow〉〈mo〉〈〈/mo〉〈mrow〉〈mn〉10〈/mn〉〈mrow〉〈mover accent="true"〉〈mn〉1〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mo〉〉〈/mo〉〈/mrow〉〈/mrow〉〈/math〉 or 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.svg"〉〈mrow〉〈mrow〉〈mo stretchy="true"〉{〈/mo〉〈mrow〉〈mn〉11〈/mn〉〈mrow〉〈mover accent="true"〉〈mn〉2〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈mn〉1〈/mn〉〈/mrow〉〈mo stretchy="true"〉}〈/mo〉〈/mrow〉〈mrow〉〈mo〉〈〈/mo〉〈mrow〉〈mn〉10〈/mn〉〈mrow〉〈mover accent="true"〉〈mn〉1〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mo〉〉〈/mo〉〈/mrow〉〈/mrow〉〈/math〉 crystallographic components and their final intensity depend on the starting texture. Texture was measured using electron-backscatter diffraction (EBSD) over large areas, with a β reconstruction software used to determine the high temperature β orientations. The texture development in Zr-2.5Nb appears similar to that reported for rolled Ti-64 at temperatures with equivalent phase fractions, although it is difficult to compare the two because of the lack of a titanium dataset as detailed as the one presented here.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324351-fx1.jpg" width="248" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): E.M.M. Ibrahim, M.A.A. Mohamed, H.M. Ali, Vyacheslav O. Khavrus, Silke Hampel, M.M. Wakkad〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrothermal synthesis as a commonly bottom-up growth method has considerable advantages for manufacturing thermoelectric nanomaterials with advanced thermoelectric properties. However, the hydrothermally synthesized thermoelectric nanostructures often show a low thermoelectric performance due to their low power factor. In this work, we report on using a hydrothermal method for the growth of n-type Bi〈sub〉2-x〈/sub〉Sb〈sub〉x〈/sub〉Se〈sub〉3〈/sub〉 nanoflakes with a fixed thickness of ∼16 quintuple-layers. The controlling of the stoichiometric composition, phase purity and crystallinity of the Bi〈sub〉2-x〈/sub〉Sb〈sub〉x〈/sub〉Se〈sub〉3〈/sub〉 nanoflakes are demonstrated by the X-ray diffraction, Raman spectroscopy, and high resolution transmission electron microscopy. We further prove that adding of antimony into Bi〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 compound mostly influences the in-plane vibration mode. The optical energy gap is sharply increased as the Sb content increases. The effect of the antimony incorporation on the electrical conductivity, Seebeck coefficient and power factor of Bi〈sub〉2-x〈/sub〉Sb〈sub〉x〈/sub〉Se〈sub〉3〈/sub〉 nanoflakes is systematically investigated. The Bi〈sub〉1.92〈/sub〉Sb〈sub〉0.08〈/sub〉Se〈sub〉3〈/sub〉 sample is found to have the highest power factor ∼13.17 μW/cm.K〈sup〉2〈/sup〉 at 470 K which is much higher than those published for other various nanostructured or bulk Bi〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 compounds. The results propose a great prospect for further enhancing the thermoelectric power factor of the Bi〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 nanostructures synthesized by this hydrothermal method. Taking into consideration the progress in Bi–Se compounds, the results of this work advocate the promise of Bi–Se nanostructures towards producing high performance thermoelectric devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Tufan Paul, Dimitra Das, Bikram Kumar Das, Saikat Sarkar, Soumen Maiti, Kalyan Kumar Chattopadhyay〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic activity of low band gap semiconductor largely restrained by high recombination rate of photogenerated charge carriers. To enhance the catalytic performance numerous protocols were adopted amongst which designing of novel hybrid via coupling of semiconductors are very intriguing from modest application point of view. Here, we report facile realization of type II heterojunctions embracing polymeric graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/GCN) and all-inorganic cesium lead halide perovskite (CsPbBrCl〈sub〉2〈/sub〉) for degradation complex organic effluents under visible-light illumination. Synthesized hybrid presented much improved performance in toxic cationic and anionic dyes degradation as compared to individual building units. Signature of favorable staggered gap junction’s formation at interface was confirmed via Mott-Schottky analysis. Such kind of junctions delay the recombination of photogenerated electron holes and facilitates active radical generation at catalyst surface thereby ensures improved photocatalytic performance. Charge transfer process in heterojunction further illustrated via Density functional theory (DFT) based calculations. Several scavenger tests have been performed to examine the impact of different active radicals in the photocatalysis which suggests manifold performance improvement in the presence of very small concentrations of EDTA. A plausible photocatalytic mechanism in accordance with the type II junction has been proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308088-ga1.jpg" width="311" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Vepika Kandjou, Ana M. Perez-Mas, B. Acevedo, M. Hernaez, Andrew G. Mayes, Sonia Melendi-Espina〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The increasing depletion of freshwater necessitates the re-use and purification of wastewaters. Among the existing separation membrane materials, graphene oxide (GO) is a promising candidate, owing to its tunable physicochemical properties. However, the widening of GO membranes pore gap in aqueous environments is a major limitation. Crosslinking agents can be incorporated to alleviate this problem. This study describes a comparative analysis of uncrosslinked and p-Phenylenediamine (PPD) crosslinked GO membranes’ water purification performance. Dip-coating and dip-assisted layer-by-layer methods were used to fabricate the uncrosslinked and crosslinked membranes respectively. The covalent interaction between GO and PPD was confirmed by Fourier Transform Infra-Red and X-ray Photoelectron Spectroscopy. The excellent membrane topographical continuity and intactness was assessed by means of Scanning Electron Microscopy, while water contact angle measurements were undertaken to evaluate and confirm membrane hydrophilicity. The improvement impact of the crosslinker was manifested on the enhancement of the stability and performance of the membranes during nanofiltration tests of aqueous solutions of methylene blue in a homemade nanofiltration cell operated at 1 bar.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307939-ga1.jpg" width="452" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Elisabete Luís Afonso, Lina Carvalho, Sara Fateixa, Carlos Oliveira Amorim, Vitor S. Amaral, Carlos Vale, Eduarda Pereira, Carlos Manuel Silva, Tito Trindade, Cláudia Batista Lopes〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Technology critical elements (TCE) are considered the vitamins of nowadays technology. Factors such as high demand, limited sources and geopolitical pressures, mining exploitation and its negative impact, point these elements as new emerging contaminants and highlight the importance for removal and recycling TCE from contaminated waters. This paper reports the synthesis, characterization and application of hybrid nanostructures to remove and recover lanthanides from water, promoting the recycling of these high value elements. The nanocomposite combines the interesting properties of graphite nanoplatelets, with the magnetic properties of magnetite, and exhibits good sorption properties towards La(III), Eu(III) and Tb(III). The sorption process was very sensitive to solution pH, evidencing that electrostatic interactions are the main binding mechanism involved. Removal efficiencies up to 80% were achieved at pH 8, using only 50 mg/L of nanocomposite. In ternary solution, occurred a preferential removal of Eu(III) and Tb(III). The equilibrium evidenced a rare but interesting behaviour, and as a proof-of-concept the recoveries and reutilization rates, at consecutive cycles, highlight the recyclability of the composite without loss of efficiency. This study evidences that surface charge and the number of active sites of the composite controls the removal process, providing new insights on the interactions between lanthanoids and magnetic-graphite-nanoplatelets.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307988-ga1.jpg" width="406" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Daria Boglaienko, Hilary P. Emerson, Yelena P. Katsenovich, Tatiana G. Levitskaia〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Technetium-99 (Tc) is a long-lived radioactive contaminant present in legacy nuclear waste streams and contaminated plumes of the nuclear waste storage sites worldwide that poses risks for human health and the environment. Pertechnetate (TcO〈sub〉4〈/sub〉〈sup〉−〈/sup〉), the most common chemical form of Tc under oxidative conditions, is of particular concern due to its high aqueous solubility and mobility in the subsurface. One approach to treatment and remediation of TcO〈sub〉4〈/sub〉〈sup〉−〈/sup〉 is reduction of Tc〈sup〉7+〈/sup〉 to less soluble and mobile Tc〈sup〉4+〈/sup〉 and its removal from the contaminated streams such as liquid secondary waste generated during vitrification of the Hanford low activity tank waste. Zero valent iron (ZVI) is a common reactive agent for reductive treatment of environmental contaminants, including reducible heavy metal ions, which can offer a potential solution to this challenge. Here, we present a comparative study of eleven commercial ZVI materials manufactured by different methods that were evaluated for the reductive removal of TcO〈sub〉4〈/sub〉〈sup〉−〈/sup〉 from an aqueous 80 mM NaCl solution at near neutral pH representing low activity waste off-gas condensate. Performance of ZVI materials was analyzed in relation to time-dependent Fe〈sup〉2+〈/sup〉 dissolution as well as pH and ORP profiles of the contact solution. Large variability in the efficiency and kinetics of Tc〈sup〉7+〈/sup〉 reduction by different ZVI materials was contingent on their origin. ZVI materials manufactured by electrolytic method exhibited superior performance, and the kinetics of the Tc〈sup〉7+〈/sup〉 reduction correlated to particle size. ZVI materials manufactured by iron pentacarbonyl reduction with hydrogen were ineffective for Tc〈sup〉7+〈/sup〉 reduction. In general, our results highlight the need for thorough performance analysis of commercial ZVI materials for any contaminant of interest.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307897-ga1.jpg" width="470" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 3 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Manzoor Ahmad, Qingsong Yang, Yanying Zhang, Juan Ling, Wasim Sajjad, Shuhua Qi, Weiguo Zhou, Ying Zhang, Xiancheng Lin, Yuhang Zhang, Junde Dong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding the microbial community succession to polycyclic aromatic hydrocarbons (PAHs) and identification of important degrading microbial groups are crucial for the designing of appropriate bioremediation strategies. In the present study, two distinct phenanthrene enriched bacterial consortia were treated against high molecular weight (Pyrene, Benzo (a) pyrene and Benzo (a) fluoranthene) and the response was studied in term of taxonomic variations by using High Throughput Illumina sequencing and qPCR analysis. Overall, the type of PAHs significantly affected the composition and the relative abundance of bacterial communities while no obvious difference was detected between bacterial communities of benzo (a) pyrene and benzo (a) fluoranthene treatments. Genera, 〈em〉Novosphingobium〈/em〉, 〈em〉Pseudomonas〈/em〉, 〈em〉Flavobacterium〈/em〉, 〈em〉Mycobacterium, Hoeflae,〈/em〉 and 〈em〉Algoriphagus〈/em〉 dominated all PAHs treatment groups indicating that they could be the key PAHs degrading phylotypes. Due to the higher abundance of gram-negative PAH-ring hydroxylating dioxygenase gene than that of gram-positive bacteria in all treated groups, we speculated that gram-negative bacteria may contribute more in the PAH degradation. The studied sediments harbored rich PAHs degrading bacterial assemblages involved in both low and high molecular weight PAHs and these findings provided new insight into the perspective of microbial PAHs bioremediation in the mangrove ecosystem.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308167-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Zizhen Li, Anthony Ivanenko, Xiangchao Meng, Zisheng Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Methanol is widely applied in photocatalysis as a scavenger of holes, and is also studied as a model system for heterogeneous photocatalysis for the production of formaldehyde. Compared to commercial processes for formaldehyde production via thermal catalytic methanol oxidation, photocatalytic oxidation of methanol to formaldehyde may be more promising when considering the following aspects: 1) lower reaction temperature and pressure (generally operated at room temperature and ambient pressure); 2) lower cost of the energy source (such as solar light) and 3) easy-to-design reactive system. Photocatalytic methanol oxidation was carried out using four different bismuth-based semiconductors (BBS), Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉, Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉, BiOBr and BiVO〈sub〉4〈/sub〉, under varying system temperature (5–50 °C), bubbling speed (0.1–1.0 LPM), catalyst dosage (0.2–2.0 g/L), and initial methanol concentration (12.5–250 mM). It was found that the formaldehyde formation rate for all photocatalysts increased as a function of each of these system parameters. Of these four BBS, it was found that Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 had the highest formaldehyde formation rate (0.081 mM/h). This work provides a new approach to produce formaldehyde using photocatalysis, and future work has also been proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307757-ga1.jpg" width="341" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Xiaohui Li, Hongxia Xu, Bin Gao, Yuanyuan Sun, Xiaoqing Shi, Jichun Wu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Laboratory saturated columns packed with granular limestone grains were used to explore the retention and remobilization of functional bacteria FA1 under various physicochemical conditions. The unique surface properties of limestone and FA1 caused some unexpected phenomena. Solution IS, cation type, temperature and surface biological property all affected FA1 retention in the columns. The IS effect was temperature dependent and initial solution pH showed little influence due to the strong buffering ability of limestone. Perturbations of solution IS caused slight release of previously retained bacteria in some columns with NaCl as the background electrolyte, while increase in flow rate caused no release at all. When CaCl〈sub〉2〈/sub〉 was the background, bacterial remobilization only occurred following both cation exchange and IS reduction. DLVO forces incorporating with surface roughness calculation were determined to assist with interpretation of interaction mechanisms. All the experimental evidences suggest the importance of cation bridging, cation exchange, surface roughness, and hydrophobic interaction in controlling bacterium transport in saturated limestone porous media.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308118-ga1.jpg" width="336" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Lei Qin, Huan Yi, Guangming Zeng, Cui Lai, Danlian Huang, Piao Xu, Yukui Fu, Jiangfan He, Bisheng Li, Chen Zhang, Min Cheng, Han Wang, Xigui Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, four kinds of porous carbon materials were used as supports to anchor gold nanoparticles (AuNPs) for catalytic reduction of nitroaromatics and 4-nitrophenol (4-NP) was employed as a model material. Results identified that carbon black (CB) restricted-Au catalyst (Au/CB) provided large specific surface area, small AuNPs size, and low cost, which showed highly catalytic activity for 4-NP reduction. Besides, with the increase of Au loadings, the catalytic activity of Au/CB was enhanced and the 1.2 wt% of Au loading exhibited the best catalytic activity with the high rate of 0.8302 min〈sup〉−1〈/sup〉 and the turnover frequency of 492.50 h〈sup〉−1〈/sup〉. Universality and real water application demonstrated that the as-prepared Au/CB catalyst was promising candidate for other phenols and azo dyes reduction and had great potential for practical application. Furthermore, after ten cycles, Au/CB still retained satisfying stability and activity. These results suggested that the larger specific surface area and smaller particle size attributing to the porosity of CB were conducive to improving the catalytic activity of Au catalysts. This design shows high potential of hierarchical porous carbon materials for highly catalytic reaction in many fields, especially the water purification.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308179-ga1.jpg" width="249" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Rahul Ram, James Vaughan, Barbara Etschmann, Joël Brugger〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The longest-lived naturally occurring isotope of polonium is polonium-210, one of the daughters of uranium-238 (138 days half-life). As a daughter radionuclide of radon-222, polonium-210 can become enriched in pore fluids in U-bearing rocks, leading to contents in excess of 100 Bq.g〈sup〉−1〈/sup〉 in some products from the mineral, coal, oil and gas industries (e.g., anode slimes in copper refinement; sludge from the oil and gas industry). Since 2006, IAEA recommendation limits require polonium and other radionuclides from the U- and Th-series decay to be regulated for products and wastes that contain 〉1 Bq.g〈sup〉−1〈/sup〉, which results in the classification of large amounts of industrial products and waste as radioactive.〈/p〉 〈p〉To develop effective methods for polonium removal and/or control, it is necessary to acquire an understanding of its aqueous chemistry. Based on a review of available experimental data, we developed a self-consistent thermochemical model for polonium in inorganic aqueous solutions. Polonium exists mainly in two oxidation states in aqueous solutions: Po(IV) and Po(II). The importance of Po(II) is unique, as Te(II) or Se(II) complexes do not appear to play a significant role in aqueous solution at room temperature. The model is used to discuss polonium speciation in some environmental and process waters.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Benjamin Tawiah, Bin Yu, Ruichao Wei, Richard K.K. Yuen, Wei Chen, John H. Xin, Bin Fei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Poly(lactic acid) (PLA) is an important bioplastic polymer with wide engineering applications, but has relatively low tensile strength and high susceptibility to flames. This manuscript reports the synthesis of a new cyclo-phosphorus-nitrogen flame retardant (FR) - hexaphenyl (nitrilotris(ethane-2,1-diyl))tris(phosphoramidate) (HNETP) for concurrent FR and tensile strength enhancement. 〈sup〉1〈/sup〉H, 〈sup〉13〈/sup〉C Nuclear Magnetic Resonance and Fourier Transform Infra-red spectra showed that HNETP was successfully synthesized. The FR properties of PLA/HNETP composites were investigated, and the peak heat release rate (PHRR) reduced by ˜ 51.3%, total heat released (THR) ˜ 43.1%, and carbon monoxide (CO) production by ˜ 46.5% with 3 wt% HNETP loading. The fire performance index increased by ˜ 65.8%, while the fire growth index decreased by ˜ 56.7%. The tensile strength and the Young’s Modulus improved to ˜ 67.4 and ˜ 87.8% respectively. A significant increase in limiting oxygen index (LOI) (32.5%) was attained with a V-0 rating in the vertical burning test. TG-IR study showed considerable reduction in pyrolysis gaseous products by the PLA/HNETP composites compared to PLA. Insignificant changes were observed in the glass transition and the melting temperature of PLA and PLA/HNETP biocomposites.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941930809X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Javed Rehman, Roshan Ali, Nisar Ahmad, Xiaodong Lv, Chunlei Guo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉It poses a great challenge to design anode materials with large capacity, excellent cyclic stability and high rate performance. In this paper, through first principle calculations, we computed electronic properties of monolayer WSe〈sub〉2〈/sub〉 with and without strain effects. Our results show that the electronic band gap decreases with strain percent. At 0% tensile strain the value of the band gap is 1.4 eV while at 10% tensile strain the band gap decreases to 0.7 eV. Therefore, the strain effect enhances the electronic conductivity and leads to an increase in the charge carrier transport. In addition, our predictions show that the adsorption energy increases with the strain. Finally, we computed the diffusion barrier for the migration of Li on the surface of a strain engineered WSe〈sub〉2〈/sub〉 monolayer. The lower barrier energy (0.24 eV) reveals that Li can easily overcome this barrier. Our results show that the strain-engineered WSe〈sub〉2〈/sub〉 monolayers are promising anode material for Li-ion battery.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): Seyedeh Marjan Bararpour, Hamed Jamshidi Aval, Roohollah Jamaati〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉AA5083 and AA5052 alloys were utilized as consumable rod and substrate, respectively, in Friction Surfacing (FS) process and a three-dimensional finite element software known as ABAQUS was employed to anticipate the materials thermo-mechanical behavior over this procedure. At that point, in order to investigate the mechanical and microstructures characteristics of the coated samples, the experimental observations and model predictions have been implemented. The results clarified that the strain rate and temperature values are not high at the interface of the substrate and coating layer, also, we observed their maximum values in a layer nearby the upper surface of the coating in the advancing side (AS). Regardless of the irregular strain rate and temperature profiles, there are no important differences in the microstructure of the materials detected in the center of the cross-sections in the direction of advancing and retreating sides (RS). It should be noted that the grain structure is not influenced by the strain energy effect which is kept in the coating layer all through the FS procedure. Moreover, we can consider the grain structure recrystallization as a contributing factor in improving the material strength of the coating which is anticipated to be proportional to the grain size in reverse.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Aref Alqahtani, Shahid Husain, Anand Somvanshi, Wasi Khan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Perovskite-type GdCr〈sub〉1-〈em〉x〈/em〉〈/sub〉Mn〈sub〉〈em〉x〈/em〉〈/sub〉O〈sub〉3〈/sub〉 (0.0 ≤ 〈em〉x〈/em〉 ≤ 0.4) nano-crystalline samples are synthesized using sol-gel auto combustion process. The effect of Mn-doping in GdCrO〈sub〉3〈/sub〉is investigated in term of structural, morphological, optical and thermal properties. X-ray diffraction (XRD) patterns confirm orthorhombic crystal structure of all the samples. The lattice parameters bond lengths and bond angles as obtained from Rietveld refinement analysis are found to vary systematically with Mn concentration. The crystallite sizes as calculated from the Scherrer's equation are found to decrease with Mn content. The Williamson-Hall (W–H) analysis reveals that the crystallite sizes decrease whereas lattice strain, stress, and energy density become more with the increase in Mn doping except for 〈em〉x〈/em〉 = 0.3.The particle size estimated using transmission electron microscopy (TEM) are consistent with that obtained through W–H analysis. Scanning electron microscopy (SEM) images with energy dispersive x-ray (EDX) analysis exhibit significant change in the surface morphology with Mn doping and ensure the elemental compositions of the samples. The Fourier transform infrared (FTIR) spectra of these samples confirm the formation of desired crystal structure with two main characteristic bands at 476 and 586 cm〈sup〉−1〈/sup〉. The optical band gap is found to reduce whereas Urbach energy increases with the increase in Mn concentration. The values of refractive index decrease in the ultraviolet region as a function of wavelength for all the samples and minimizes at the main absorption peak position as observed in the UV/Vis. spectra. The value of heat capacity at constant pressure (〈em〉C〈/em〉〈sub〉〈em〉p〈/em〉〈/sub〉) decreases with Mn doping except for 30% Mn concentration. Therefore, the present investigation suggests that the properties of GdCrO〈sub〉3〈/sub〉 system can be tuned with the appropriate doping of Mn for the potential applications.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): Xinghua Zhu, Qingshuang Xie, Haibo Tian, Ming Zhang, Zongyan Gou, Shuai He, Peng Gu, Haihua Wu, Jitao Li, Dingyu Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Usually, ZnO thin films used in ultraviolet photodetector exhibit good photoresponse property when ultraviolet signal is strong enough. However, due to the high dark current, pure ZnO is insusceptible to weak ultraviolet signal. To address this problem, lithium-doped ZnO (LZO) thin films were prepared using the sol-gel method in this study. Results revealed that the LZO thin film doped with low concentration (2 at.%) had a dark current about 10 times lower than the pure ZnO. In addition, the ultraviolet with a low irradiance of 90 μW/cm〈sup〉2〈/sup〉 was used. According to the results of the investigations on the external quantum efficiency and responsivity, the inherent photocurrent generation ability of ZnO was not deteriorated through low concentration lithium doping. LZO thin film doped with 2 at.% exhibited a high sensitivity to weak ultraviolet signal --- the signal-to-noise ratio was enhanced by approximately 10 times compared with that of pure ZnO. This study indicates that LZO thin films with low doping concentration are promising application on weak ultraviolet signal photodetector.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): Jian Lan, Weidong Xuan, Yu Han, Yongshun Li, Huaizhou Wu, Wei Shao, Chuanjun Li, Jiang Wang, Zhongming Ren〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of hot isostatic pressing on the tensile property of single crystal superalloys at elevated temperature is studied experimentally. The results show that the high temperature elongation of nickel based single crystal superalloys is obviously enhanced by hot isostatic pressing, while the yield strength is unchanged. Besides, it is found that the hot isostatic pressing causes the change of fracture surface. The enhancement of elongation and the change of fracture behavior are discussed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): Z.M. Li, X.N. Li, C.Y. Wang, Y.H. Zheng, Q.X. Yu, X.T. Cheng, N.J. Li, L.X. Bi, Q. Wang, C. Dong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The heat resistance of copper alloys is desirable to improve while it services at high temperature as electrically and thermally conductive components. In present paper, the strengthening pattern of nickel-based superalloys is expected to be applied in copper alloys. Here the Cu〈sub〉50〈/sub〉Ni〈sub〉37.5〈/sub〉〈em〉M〈/em〉〈sub〉12.5〈/sub〉 (〈em〉M〈/em〉 = Al, Cr, Mo) alloys were prepared by vacuum arc melting and heat-treated in the corresponding conditions to obtain three different kinds of typical microstructure. The room temperature (RT) properties (hardness and resistivity) and high temperature properties (melting point, softening temperature and variable temperature resistivity) of the three alloys are contrasted and analyzed in detail. The Cu〈sub〉50〈/sub〉Ni〈sub〉37.5〈/sub〉Al〈sub〉12.5〈/sub〉 alloy strengthened through the γ′ phase coherent precipitation shows the best conductivity and highest hardness (5.47 %IACS (International Annealed Copper Standard) and 310.1 HV). The splitting of the γ′ phase is contributing to hardening at high aging temperature. The resistivity-temperature behavior of the three alloys shows that the resistivity with rising temperature consists of the ideal lattice resistivity and the resistivity increment due to the defects. The Cu〈sub〉50〈/sub〉Ni〈sub〉37.5〈/sub〉Al〈sub〉12.5〈/sub〉 alloy has the smallest room temperature resistivity and its resistivity maintains the lowest during the whole heating process (RT-1077K). Therefore, the coherent precipitated γ′ phase is expected to improve the heat resistance of the copper alloys while maintaining its electrical conductivity.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819325708-fx1.jpg" width="282" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): Cui-Ning Feng, Xiao-Ye Zhan, Pan Li, Xiao-Feng Guo, Dan Li, Xiu-Cheng Zheng, Guang-Ping Zheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Glucose-derived porous activated carbon materials (AGC-600-4 and AGC-180-〈em〉x〈/em〉) are prepared using ZnCl〈sub〉2〈/sub〉 as the etching agent via impregnation treatment and hydrothermal method followed by the calcination process. The analytic results indicate that the obtained materials exhibit higher specific surface area and superior double-layer capacitive behavior than the corresponding pristine carbon (GC-600 and GC-180) when used as electrode materials for supercapacitors. Moreover, compared with the AGC-600-4 nanosheets, the optimal AGC-180-4 microspheres have a high specific surface area of 1713 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉 and a maximum specific capacitance of 235.9 F g〈sup〉−1〈/sup〉 at a current density of 1.0 A g〈sup〉−1〈/sup〉 in the three-electrode system. Meanwhile, AGC-180-4 also exhibits better capacitive properties than AGC-600-4 in the two-electrode system, showing an excellent cyclic stability with a high energy density of 24.63 Wh kg〈sup〉−1〈/sup〉 at the power density of 949.5 W kg〈sup〉−1〈/sup〉. It is thus demonstrated that AGC-180-4 could be ideal electrode materials for supercapacitor due to its unique etched spherical structure and excellent electrochemical properties.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819325903-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): Ilham Bezza, Erwann Luais, Fouad Ghamouss, Mustapha Zaghrioui, François Tran-van, Joe Sakai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An 〈em〉in-situ〈/em〉 temperature-controlled Raman spectroscopy aided unique electrode fabrication technique has been developed for Li-ion battery applications, ensuring superior electrochemical quality of the multi-porous LiCoO〈sub〉2〈/sub〉 films with higher stoichiometric purity of high temperature (HT)-LiCoO〈sub〉2〈/sub〉 phase, by observing the structural changes during the fabrication process and thus confirming the transformation from the low temperature (LT)-LiCoO〈sub〉2〈/sub〉 phase. This much desired simple process is not only free of any sort of binders or carbon additives but also works at atmospheric pressure, leading to a very simple deposition technique using a homemade and inexpensive set-up. Also, the time of depositions were varied and resultant films we investigated for their electrochemical performance. The high-resolution scanning electron microscope (SEM) observation has revealed not only a μm-size porous structure but also three-dimensional cross-link with 10 nm-level pores of the material, which ensured the much-desired porosity for high-performance cathodes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): S.C. Ram, K. Chattopadhyay, I. Chakrabarty〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Functionally graded in-situ A356-Mg〈sub〉2〈/sub〉Si composites by centrifugal casting method have been studied with varying percentage of extra Mg additions during synthesis. The coarse primary Mg〈sub〉2〈/sub〉Si particles and the Si morphology in eutectic do not yield appreciable mechanical properties. Solution treatment and artificial ageing (T6) are effective means to improve mechanical properties by refining the as-cast structure with additional formation of very fine precipitates during ageing. The microstructural evolution has been assessed by optical, scanning and transmission electron microscopy and X-ray diffraction analysis. Ageing curves are plotted with hardness versus ageing time. High temperature tensile properties are evaluated at room temperature, 150 °C and 300 °C at different layers of the graded composites and are compared between as-cast and T6 conditions. The tensile fracture mechanisms are explained from fractographs. A remarkable improvement in high temperature tensile strength at 150 °C with adequate ductility is observed in T6 condition with respect to as-cast condition.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819325721-fx1.jpg" width="264" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): Taiqian Mo, Zejun Chen, Boxin Li, Hongtao Huang, Weijun He, Qing Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The impact of strain path on microstructure and mechanical properties in AA1100/AA7075 laminated metal composite was investigated in present work. The results indicate that the plastic instabilities occurred in the hard layer can be inhibited effectively and the mechanical properties of the composite were improved obviously after the cross rolling (CR) process. The formation of continuous and straight interface was attributed to the difference in flow properties between the constituent layers was decreased after CR process. It is found that the strain path change during CR results in the typical rolling texture is shifted from the ideal Brass (110)〈112〉 along the 〈em〉α〈/em〉-fiber to the near ND-rotated Brass (011)〈755〉 component, promoting a better mechanical isotropy of the AA1100/AA7075 laminated metal composite. In addition, the Al/Al alloy laminated metal composite with continuous layer structure exhibits better load-bearing capacity in hard layers than the wave layer structure during deformation, which is a main reason for increasing of the strength.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): N. Patra, C.L. Prajapat, P.D. Babu, S. Rai, S. Kumar, S.N. Jha, D. Bhattacharyya〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Heusler alloy of Co〈sub〉2〈/sub〉FeSi (CFS) is a promising candidate for spintronics applications due to its high magnetic moment and high spin polarization. In this report two series of CFS thin films of approximate thickness of 1000 Å were prepared using Pulsed Laser Deposition (PLD) technique by two separate routes, viz., (i) by depositing at elevated substrate temperature and (ii) by depositing at room temperature followed by post-deposition annealing under vacuum. The effects of these two thermal growth processes on the structural and magnetic properties of the films have been studied in detail here. X-ray diffraction study suggests that similar to the bulk target cubic Heusler phase is maintained in the thin films prepared by both the processes, however, X-ray reflectivity study shows that the films deposited at elevated substrate temperatures have higher density and surface roughness than the other set. Co/Fe atomic ratio in the films was found to remain near stoichiometry up to high temperature in both the series of samples though atomic percentage of Si is found to be higher in the samples. Synchrotron based Extended X-ray absorption fine structure (EXAFS) measurements indicate higher 〈em〉3d-3p〈/em〉 (Co-Si) hybridization for the series of samples prepared at elevated temperature while stronger 3〈em〉d-3d〈/em〉 (Co-Fe) hybridization for the samples prepared with post deposition annealing. EXAFS study also indicated presence of Co/Fe type antisite disorder which increases with increase in the substrate temperature. Finally from detail magnetic measurements it was observed that the films prepared by post-deposition annealing process have lesser crystallinity, magnetic ordering and magneto crystalline anisotropy in comparison to the films grown with elevated substrate heating.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 805〈/p〉 〈p〉Author(s): Hao Guo, Taotao Sun, Liguo Yue, Ning Wu, Qi Li, Wenqing Yao, Wenhu Yang, Wu Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a kind of energy storage device, supercapacitors have attracted the attention of researchers, and the development of high-performance electrode materials is also the focus of attention. In this paper, template synthesis and pyrolysis were combined to prepare high performance porous carbon electrode materials. The carbonized electrode material effectively increased the capacitance storage capacity and charge transfer rate. The results revealed that the derivative had a relatively low charge-transfer resistance and high specific capacitance of 1059 F·g〈sup〉−1〈/sup〉 at a current density of 1.0 A·g〈sup〉−1〈/sup〉 in a three-electrode system. To further exploring practical application, a device based on the derivative and hemp-activated carbon asymmetric supercapacitor was assembled in 0.1 M Na〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 neutral electrolyte, which exhibited an energy density of 20.35 Wh·kg〈sup〉−1〈/sup〉 at a power density of 400 W·kg〈sup〉−1〈/sup〉. Interestingly, it showed capability retention of nearly of 91.7% and columbic efficiency of 100% even after 10000 charging/discharging cycles in the neutral electrolyte.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819325691-fx1.jpg" width="365" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 379〈/p〉 〈p〉Author(s): Shuyu Jia, Jialu Wu, Lin Ye, Fuzheng Zhao, Tong Li, Xu-Xiang Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Chlorination can contribute to the enrichment of specific antibiotic resistance genes (ARGs) in drinking water, but the underlying molecular ecological mechanisms remain unknown, which may hinder the assessment and control of the resulting health risks. In this study, metagenomic assembly and Resfams annotation were used to profile the co-occurrence patterns of ARGs, mobile genetic elements (MGEs) and their bacterial hosts, as well as the correlations of potential pathogens with the antibiotic resistome, in a full-scale drinking water treatment and transportation system. Seven ARG types involved in different resistance mechanisms occurred in drinking water and chlorination enhanced the total abundance of the ARGs (〈em〉p〈/em〉 〈  0.05). The ARGs encoding resistance-nodulation-cell division and ATP-binding cassette antibiotic efflux pumps predominated in all the samples and were primarily responsible for the ARG accumulation. After chlorination, the ARGs were primarily carried by predominant 〈em〉Sphingomonas〈/em〉, 〈em〉Polaromonas〈/em〉, 〈em〉Hyphomicrobium〈/em〉, 〈em〉Acidovorax〈/em〉, 〈em〉Pseudomonas〈/em〉 and 〈em〉Fluviicola〈/em〉. Further, enrichment of the bacterial hosts and MGEs greatly contributed to alteration of the antibiotic resistome. 〈em〉Pseudomonas alcaligenes〈/em〉, carrying multiple ARGs, was identified as a potential pathogen in the chlorinated drinking water. These findings provide novel insights into the host-ARG relationship and the mechanism underlying the resistome alteration during drinking water chlorination.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307940-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Nejeh Hamdaoui, Yashar Azizian-Kalandaragh, Mouadh Khlifi, Lotfi Beji〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of Cd-doping on physical properties of Ni〈sub〉0.6-〈em〉x〈/em〉〈/sub〉Cd〈sub〉〈em〉x〈/em〉〈/sub〉Mg〈sub〉0.4〈/sub〉Fe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 spinel ferrite has been investigated. Scanning electron spectroscopy (SEM) confirms the formation of grain and grain boundaries in these samples and the presence of all chemical elements introduced was confirmed by EDS. The X-ray analyses indicate that all the compounds have the cubic structure with 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈mi〉F〈/mi〉〈mi〉d〈/mi〉〈mrow〉〈mover accent="true"〉〈mrow〉〈mn〉3〈/mn〉〈/mrow〉〈mo stretchy="true"〉¯〈/mo〉〈/mover〉〈/mrow〉〈mi〉m〈/mi〉〈/mrow〉〈/math〉 space group, cell parameter increase which Cd content. A ferromagnetic state at room temperature for all compounds is detected by a magnetization measurement of hysteresis loops. We note that the saturation magnetization increases with Cd content, however, the remnant magnetization, and the corrective field decreases. DC electrical conductivity analysis shows a semiconductor behavior for all sample. In addition, non-overlapping small polaron tunneling (NSPT) and the overlapping large polaron tunneling (OLPT) are the dominants conductions mechanisms in our samples.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Beiyue Ma, Chang Su, Xinming Ren, Zhi Gao, Fan Qian, Wengang Yang, Guoqi Liu, Hongxia Li, Jingkun Yu, Qiang Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fly ash is a typical industrial solid waste that seriously affects human health and ecological balance. In order to recycle the fly ash, in this work, porous mullite ceramics were successfully fabricated with fly ash and bauxite via reaction synthesis process. Effects of firing temperature (1450–1550 °C), silicon carbide addition amount (0–15 wt%), and potash feldspar addition amount (0–16 wt%) on the mullite porous ceramics were systematically investigated. It was found that increasing the silicon carbide addition amount or raising firing temperature was favourable for improving the cold compressive strength and thermal shock resistance of the porous ceramics. Consequently, the porous ceramics with 10 wt% silicon carbide, 4–12 wt% potash feldspar had optimal overall performances. The closed porosity and cold compressive strength ranges were 14.79%–18.57% and 217.18–236.67 MPa, respectively. The thermal cycles were 7–9 times, and the thermal conductivity was reached to 2.19–2.52 W m〈sup〉−1〈/sup〉 K〈sup〉−1〈/sup〉 at 800 °C. This work provides a convenient and promising method for the utilization of fly ash.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881932362X-fx1.jpg" width="496" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Daria N. Vtyurina, Irina A. Kaurova, Galina M. Kuz'micheva, Victor B. Rybakov, Dmitry Yu. Chernyshov, Evgeny V. Khramov, Sergey V. Firstov, Vladimir N. Korchak〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Promising luminescent CsCd〈em〉X〈/em〉〈sub〉3〈/sub〉 (〈em〉X〈/em〉 = Cl, Br) single crystals, both nominally-pure and doped with bismuth, have been studied comprehensively by X-ray diffraction, X-ray synchrotron radiation, and X-ray absorption spectroscopy. Crystal structure refinement shows vacancies in the Cs crystallographic site and partial substitution of Cd〈sup〉2+〈/sup〉 ions by Bi〈sup〉3+〈/sup〉 ones in both CsCdCl〈sub〉3〈/sub〉 and CsCdBr〈sub〉3〈/sub〉 (point defects Bi〈sub〉Cd〈/sub〉〈sup〉•〈/sup〉), which is consistent with the results of X-ray absorption spectroscopy. The assumed presence of Bi〈sup〉1+〈/sup〉 ions in the Cs〈sup〉1+〈/sup〉 sites of doped CsCd〈em〉X〈/em〉〈sub〉3〈/sub〉 (〈em〉X〈/em〉 = Cl, Br) crystals is not confirmed. In the photoluminescence spectra of Bi-doped CsCdCl〈sub〉3〈/sub〉 and CsCdBr〈sub〉3〈/sub〉 crystals, a single band in the near-IR spectral range with a maximum around 1000 nm is caused by point defects Bi〈sub〉Cd〈/sub〉〈sup〉•〈/sup〉. Photoluminescence spectra and decay kinetics of Bi-doped CsCd〈em〉X〈/em〉〈sub〉3〈/sub〉 (〈em〉X〈/em〉 = Cl, Br) indicate their promising use as luminescent materials.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Sung-Hsiu Huang, Cheng-Yi Tong, Tsung-Eong Hsieh, Jyh-Wei Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉For the development of advanced nanoscale multilayer protective coatings, proper design of microstructure and chemical composition of carbon containing sequential transition metal nitride nanolayers is an important issue. In this work, five different nanostructured CrCN/ZrCN multilayer coatings were deposited periodically by cathodic arc evaporation. The bilayer period of the CrCN/ZrCN multilayer coatings was kept at 20 nm. The C〈sub〉2〈/sub〉H〈sub〉2〈/sub〉 gas flow ratio was adjusted from 6.3 to 20.0% for achieving CrCN/ZrCN multilayer coatings with 2.3–4.2 at.% carbon content. Nanolaminated CrCN and ZrCN nitride layers and thin amorphous carbon nitride mixed nanolayers ∼5 nm thick were obtained as the carbon content reached 4.2 at.%. It was found that the hardness and adhesion quality were strongly improved by the carbon addition to the CrCN/ZrCN multilayer coatings. An increase of 2.6–4.6 GPa in hardness was found for the CrCN/ZrCN multilayer coatings due to the balance of solution hardening effect of carbon atoms and the softening by the amorphous mixed nanolayer. An optimal combination of high hardness, 28.9 GPa, and good adhesion, 41 N of upper critical load were achieved when the carbon content was 4.2 at.% for the CrCN/ZrCN multilayer coatings.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Hanfei Zhu, Yuyao Zhao, Yingying Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Epitaxial BiFeO〈sub〉3〈/sub〉 thin films with (100), (110) and (111) orientations were grown on the SrRuO〈sub〉3〈/sub〉-buffered SrTiO〈sub〉3〈/sub〉 substrates by using an off-axis magnetron sputtering. Unlike the BiFeO〈sub〉3〈/sub〉(110) and BiFeO〈sub〉3〈/sub〉(111) thin films that exhibited a single rhombohedral phase structure, a dominant rhombohedral phase accompanying with a small amount of tetragonal phase was identified in the BiFeO〈sub〉3〈/sub〉(100) thin film. In particular, the leakage currents and ferroelectric polarizations of sputtered BiFeO〈sub〉3〈/sub〉 thin films were focused on and these films showed utterly different current density-electric field (〈em〉J〈/em〉-〈em〉E〈/em〉) behaviors whether in the positive or negative electric field. Among the three films, the ferroelectric polarization of the BiFeO〈sub〉3〈/sub〉(100) thin film presented a good frequency stability and had the maximum remnant polarization of 〈em〉P〈/em〉〈sub〉r〈/sub〉 ∼ 78 μC/cm〈sup〉2〈/sup〉 @ 10 kHz, which could be further demonstrated by pulsed polarizations of films. The distinct differences in electrical properties of orientation-engineered BiFeO〈sub〉3〈/sub〉 thin films in present case can be attributed to their different crystallographic orientations and microstructures.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324405-fx1.jpg" width="329" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Lihong Wang, Hongtao Guan, Jianqiao Hu, Qiang Huang, Chengjun Dong, Wei Qian, Yude Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Porous jute biomass carbon (PJBC) composited by Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanoparticles were successfully prepared by a chemical coprecipitation method at a low temperature of 60 °C, which is very simple to prepare a high degree of purity of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanoparticles. The structure, morphology, and microwave absorption performances of the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/PJBC composites were investigated in detail. Due to the porous structure and large interfaces between Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 and PJBC, the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/PJBC composites show excellent microwave absorption performances. The minimum reflection loss (RL) value of −39.5 dB is obtained for the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/PJBC composites at the frequency of 6.4 GHz. When the thickness is only 1.6 mm, an effective absorption bandwidth (RL ≤ −10 dB) for 5 GHz is achieved from 13.8 to 17.8 GHz. The excellent microwave absorption performances for the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/PJBC composites are rooted in enhanced impedance matching, large interfaces, ionic polarization, eddy loss, natural resonance, and multiple reflection and scattering. Consequently, considering market applications and the cost, the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/PJBC composite in this work can be a promising candidate for microwave absorber.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/PJBC composites prepared by a chemical coprecipitation method at a low temperature of 60 °C exhibit the microwave absorbing performance.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881932448X-fx1.jpg" width="476" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): N.E. Dubinin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The concentration dependencies of the self-diffusion coefficients in liquid Na–K and K–Cs alloys at 〈em〉T〈/em〉 = 373 K are calculated in the framework of the linear trajectory approximation in conjunction with the square-well (SW) model treated by the mean spherical approximation in the semi-analytical representation. It is shown that this approach allows to achieve a good description of diffusion properties for liquid binary metal alloys at the same values of the SW parameters that lead to a good description of the structure and entropy for alloys under consideration.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Xiang Wu, Richu Wang, Chaoqun Peng, Yan Feng, Zhiyong Cai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gas atomized Cu-3Ag-0.5Zr and Cu-3Ag-0.5Zr-0.4Cr-0.35Nb (wt.%) powders were compacted by hot isostatic pressing (HIP) and followed by forging. The microstructures and tensile properties at room and elevated temperatures (400 °C, 450 °C and 500 °C) were investigated. The continuous Ag precipitates (5–25 nm) and Cu〈sub〉4〈/sub〉AgZr (200–500 nm) particles are the main strengthening phases in the Cu-3Ag-0.5Zr alloy. The yield strength and ultimate tensile strength at room temperature are enhanced by 104 MPa and 83 MPa, respectively, due to the introduction of Cr〈sub〉2〈/sub〉Nb (50–80 nm) particles. Besides, the strength at elevated temperatures is also improved. For both the alloys, the discontinuous Ag precipitates near the grain boundaries result in a weak grain boundary cohesion when tested at 450 °C, leading to the lowest elongation. The Cr〈sub〉2〈/sub〉Nb and Cu〈sub〉4〈/sub〉AgZr particles are extremely stable when tested at 500 °C, which benefits to the performance enhancements at elevated temperatures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Wenjing Zhang, Huihong Liu, Hua Ding, Hidetoshi Fujii〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The rolled Ti–15V–3Cr–3Sn–3Al (Ti-15-3) alloy (metastable 〈em〉β〈/em〉 titanium alloy) sheet with an average grain size of 44.0 μm was subjected to friction stir processing (FSP) at a tool rotation speed of 250 rpm and a tool traverse speed of 100 mm/min (250–100). Thereafter, a fine-grained (∼6.6 μm) and relatively equiaxed microstructure with a high angle grain boundary (HAGB) ratio of 74.5% was observed in the stir zone (SZ). Superplastic tensile tests were then conducted on this microstructure at the temperatures ranging from 600 °C to 800 °C and strain rates range of 1 × 10〈sup〉−4〈/sup〉-1 × 10〈sup〉−2〈/sup〉 s〈sup〉−1〈/sup〉, and an excellent low-temperature superplasticity (LTSP) with the elongation of 463% was obtained at 650 °C and 1 × 10〈sup〉−4〈/sup〉 s〈sup〉−1〈/sup〉. In addition, the microstructure in the gauge section of the tensile specimens interrupted at different engineering strains of 20%, 50%, 200%, and 463% (tensile fractured) at the optimal superplastic tensile condition of 650 °C and 1 × 10〈sup〉−4〈/sup〉 s〈sup〉−1〈/sup〉 was studied. It was found that the precipitated 〈em〉α〈/em〉 phase increased with the increasing strain, which contributed to the achievement of an enhanced LTSP by inhibiting the grain growth. Moreover, the α grains with a finer grain size of 4.4 μm was observed in the gauge section of the tensile fractured specimen and this was attributed to the occurrence of continuous dynamic recrystallization (CDRX). Therefore, the superplastic deformation mechanism of the Ti-15-3 alloy is recognized as grain boundaries sliding (GBS) accompanied with dislocation movement and CDRX at 650 °C and 1 × 10〈sup〉−4〈/sup〉 s〈sup〉−1〈/sup〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): G.E. Nikiforova, O.N. Kondrat'eva, A.V. Tyurin, M.A. Ryumin, V.N. Guskov, K.S. Gavrichev〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lutetium orthotantalate with 〈em〉M′〈/em〉-fergusonite type structure was synthesized using a reverse coprecipitation method. Phase and chemical composition, as well as microstructure of the synthesized sample, were characterized by X-ray diffraction (XRD), μ-X-ray fluorescence and Fourier-transform infrared spectroscopies, and scanning electron microscopy. Heat capacity of 〈em〉M′〈/em〉-LuTaO〈sub〉4〈/sub〉 was first studied by adiabatic and differential scanning calorimetry (DSC) in the temperature range from 10 to 1300 K. Using a temperature dependence of heat capacity, the standard thermodynamic functions (entropy 〈em〉S〈/em〉〈sub〉m〈/sub〉〈sup〉o〈/sup〉(〈em〉T〈/em〉), enthalpy change 〈em〉H〈/em〉〈sub〉m〈/sub〉〈sup〉o〈/sup〉(〈em〉T〈/em〉)〈em〉–H〈/em〉〈sub〉m〈/sub〉〈sup〉o〈/sup〉(0) and derived Gibbs energy 〈em〉Ф〈/em〉〈sub〉m〈/sub〉〈sup〉o〈/sup〉(〈em〉T〈/em〉)) were calculated in the range of 〈em〉T〈/em〉→0–1300 K. The standard molar entropy of 〈em〉M′〈/em〉-LuTaO〈sub〉4〈/sub〉 at 298.15 K is 123.12 ± 0.50 J K〈sup〉−1〈/sup〉 mol〈sup〉−1〈/sup〉. A comparison of the experimental heat capacity values, obtained by DSC, with those calculated using the empirical Neumann-Kopp rule showed a reasonable agreement between the two sets of data only up to ≈1000 K. The high-temperature evolution of the lattice parameters for 〈em〉M′〈/em〉-LuTaO〈sub〉4〈/sub〉 was studied by high-temperature XRD (HTXRD). According to the high-temperature heat capacity study and the HTXRD measurements, there were no phase transformations up to 1300 K. Based on the HTXRD data, the linear and volume thermal expansion coefficients were obtained for the first time.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): V.I. Voronkova, E.P. Kharitonova, E.I. Orlova, N.I. Sorokina, T.A. Sorokin, A.M. Antipin, E.D. Baldin, V.V. Grebenev〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Undoped and Mg-doped Nd〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 oxymolybdate single crystals and polycrystalline samples have been prepared by flux growth and solid-state reactions. The materials have been characterized by X-ray diffraction, EDS microanalysis, X-ray structure analysis, differential scanning calorimetry, thermogravimetry, and impedance spectroscopy. The (MgO)〈sub〉〈em〉x〈/em〉〈/sub〉(Nd〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉)〈sub〉(1–〈em〉x〈/em〉)/2〈/sub〉 solid solution series has been shown to extend to 〈em〉x〈/em〉 = 0.20. Doping of Nd〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 single crystals with Mg leads to splitting of the Mo, Nd1, and O2 sites. A structural model in which the Mg atoms partially substitute for Mo atoms and reside near the Mo site, 0.28 Å from it, ensures the best agreement with the observed diffraction pattern. The conductivity of the undoped and doped polycrystalline samples approaches 10〈sup〉−4〈/sup〉 S/cm at 800 °C and is assumed to have an anionic nature.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324764-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Chaocheng Liu, Xucai Kan, Xiansong Liu, Shuangjiu Feng, Jiyu Hu, Wei Wang, Khalid Mehmood Ur Rehman, Mudssir Shezad〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Conventional permanent hexagonal ferrites may prohibit the soft magnetic properties through the effort of doping behavior. A typical case of this magnetic conversion is Co–Ti doped M-type strontium hexaferrites. On the basis of this system, we developed a novel foundation of La doped CoTi-strontium hexaferrites in present work and a promising result were obtained. Polycrystalline Sr〈sub〉1-〈em〉x〈/em〉〈/sub〉La〈sub〉〈em〉x〈/em〉〈/sub〉Fe〈sub〉10〈/sub〉CoTiO〈sub〉19〈/sub〉 (〈em〉x〈/em〉 = 0.00–0.10) hexaferrites present the admirable characteristics as general soft ferrites (high permeability 〈em〉μ〈/em〉, low core loss 〈em〉P〈/em〉〈sub〉cv〈/sub〉), and retain the properties of permanent ferrites simultaneously. This extraordinary performance exhibit more appropriate candidate for multilayer inductors contrast to normal soft magnetic materials. Meanwhile, we presented a series of measurement results to investigate the morphology and texture of the sample, which revealed the internal structural feature systematically.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Magnetoplumbite crystal structure and spin directions of 2〈em〉a〈/em〉 and 4〈em〉f〈/em〉〈sub〉2〈/sub〉 sites for M-type strontium hexaferrites.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324235-fx1.jpg" width="278" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 379〈/p〉 〈p〉Author(s): Ngan Hong Le, Yo-han Han, Hyunsook Jung, Joungmo Cho〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Highly efficient catalytic reaction systems are developed to rapidly and selectively oxidize 2-chloroethyl ethyl sulfide (CEES). In the systems, precursors containing bromide(s) and nitrate anions are chosen for the development of cyclic catalytic loop and the effect of acids on the selective oxidation of CEES are investigated by the addition of several homogeneous acid catalysts. The experimental results reveal that addition of acid results in a higher concentration of tribromide, which is reported as a key component for the observed activity in the catalytic solution. As a consequence, a dramatic improvement in catalytic activity is observed, especially when the molar amount of acid is controlled to be more than twice the initial concentration of tribromide. For the efficient design of a catalytic system, heterogeneous acid catalysts possessing different ratios of Brønsted to Lewis acid sites are also considered. Compared to reaction systems catalysed by homogeneous acids, similar reaction behaviour is observed for the reaction with Amerlyst-15, while those with other heterogeneous catalysts, containing Lewis or mixed acid sites in their structure, exhibits an adverse effect of selective sulfoxidation, mainly due to the adsorption of anions onto Lewis sites and consequential deconstruction of the catalytic loop.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307836-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 379〈/p〉 〈p〉Author(s): Jian Chen, Xinghui Xia, Haotian Wang, Yawei Zhai, Nannan Xi, Hui Lin, Wu Wen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The partition of polycyclic aromatic hydrocarbons (PAHs) among water-soil-air is temperature-dependent. Thus, we hypothesized that climate warming will affect the accumulation and uptake pathway of PAHs in plants. To test this hypothesis, enclosed soil/water-air-plant microcosm experiments were conducted to investigate the impact of warming on the uptake and accumulation of four PAHs in spinach (〈em〉Spinacia oleracea〈/em〉 L.). The results showed that root uptake was the predominant pathway and its contribution increased with temperature due to the promoted acropetal translocation. Owing to the increase in freely dissolved concentrations of PAHs in soil pore water, the four PAH concentrations in roots increased by 60.8–111.5% when temperature elevated from 15/10 to 21/16 °C. A model was established to describe the relationship between bioconcentration factor of PAHs in root and temperature. Compared with 15/10 °C, the PAH concentrations in leaves at both 18/13 and 21/16 °C elevated due to the increase in PAH concentrations in air, while slightly decreased when temperature elevated from 18/13 to 21/16 °C because the PAH concentrations in air decreased, resulting from accelerated biodegradation of PAHs in topsoil. This study suggests that warming will generally enhance the PAH accumulation in plant, but the effect will differ among different plant tissues.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307848-ga1.jpg" width="241" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Min-Su Lee, Yong-Taek Hyun, Tea-Sung Jun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have performed macroscopic tensile and nanoindentation tests to investigate the effect of oxygen content on the global and local strain rate sensitivity of grades 1, 2 and 4 commercially pure titanium (CP–Ti). Electron backscatter diffraction (EBSD) was used to characterise the crystallographic texture of target samples and orientation of target grains. Slip activities were anticipated by Schmid factor analysis, indicating the relative incidence of 〈a〉 type prismatic and basal slips in the macroscopic region, and similarity of potential local deformation between comparative grain orientations. Further slip trace analysis around the residual impressions showed similar slip activity in equivalent orientations regardless of oxygen content. Global and local strain rate sensitivity were evaluated with respect to the influence of texture and grain orientations, respectively. Significant oxygen-dependent rate sensitivity is observed such that the rate sensitivity is inverse to the oxygen content and this effect is agreed on at both macro- and microscopic levels. These findings are potentially important for understanding the influence of oxygen content on the dwell fatigue of Ti alloys and correlating the intrinsic mechanism at the microscopic level to the macroscopic deformation behaviours.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819324107-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Y. Al-Hadeethi, S.A. Tijani〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nuclear medicine makes use of different gamma emitting radioactive sources which necessitates a reliable way of reducing unnecessary exposure of nuclear medicine personnel and the general public in the vicinity of these radioactive sources. Radiation shielding is one of the major ways through which the medical personnel and the public are protected from the harmful effects of ionizing radiation. A material that combines transparency, non-toxicity and radiation shielding ability is of high interest presently in the medical environment. This work aims to determine the suitability of lead-free transparent 50BaO-(50-x)borosilicate-xBi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 glass system for radiation shielding purposes at diagnostic nuclear medicine energies and to compare its properties with that of transparent lead glass and ordinary concrete. The results of this work show that while all the glass samples show comparable shielding properties with the lead glass, glass sample G5 is the best lead glass substitute. All the studied glasses are lighter than lead glass and showed better shielding properties than ordinary concrete.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Liang Zheng, Wenjie Zhang, Qi Wang, Hong Zhang, Zhou Yu, Cuihua Cheng, Yong Zhang, Ming Lei, Yong Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉MgB〈sub〉2〈/sub〉 bulks with NaCl doping amount ranging from 0–30 at% have been prepared by hot pressed sintering process. With the increase of NaCl doping amount, the 〈em〉c〈/em〉 axis lattice parameter of MgB〈sub〉2〈/sub〉 monotonously increases, indicating the substitution of Mg atoms by larger Na atoms. Meanwhile, the intensity of diffraction peaks of both NaCl and impurity phase of MgO increases. More compact morphology was found in the NaCl doped MgB〈sub〉2〈/sub〉 samples. The critical transition temperature (〈em〉T〈/em〉〈sub〉c〈/sub〉) decreases from 38.2 K to 36.8 K with the increase of NaCl doping amount from 0 to 30 at%, and the corresponding transition width of 〈em〉T〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉 (Δ〈em〉T〈/em〉〈sub〉c〈/sub〉) increases from 0.5 K to 1.8 K. When the doping amount of NaCl is not exceeding 10 at%, the 〈em〉J〈/em〉〈sub〉c〈/sub〉 value is about 10〈sup〉6〈/sup〉 A/cm〈sup〉2〈/sup〉 at 4.2 K, 3 T, and 5 × 10〈sup〉5〈/sup〉 A/cm〈sup〉2〈/sup〉 at 10 K, 3T. 〈em〉J〈/em〉〈sub〉c〈/sub〉 performance of the 5 at% NaCl doped MgB〈sub〉2〈/sub〉 sample (NC05) reaches 6.8 × 10〈sup〉5〈/sup〉 A/cm〈sup〉2〈/sup〉 at 20 K, 2T, which improves approximately 20% compared to the pure one, attributing to the better grain connectivity of MgB〈sub〉2〈/sub〉 and enhancement of flux pinning force by NaCl doping.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 803〈/p〉 〈p〉Author(s): Yu Wang, Chao Fang, Xiang Li, Zhou Peng Li, Bin Hong Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉LaB〈sub〉6〈/sub〉 is a unique plasmonic material, for which the localized surface plasmon resonance (LSPR) absorption band intrinsically lies in the near infrared (NIR) region. In this work, we synthesized spherical LaB〈sub〉6〈/sub〉 nanoparticles with a tunable size within 50–200 nm. The optical properties of these LaB〈sub〉6〈/sub〉 nanospheres were found to be sensitive to the thickness of surface oxide layer that was formed during the synthesis, purification and dispersion processes. In order to enhance the stability of LaB〈sub〉6〈/sub〉 nanoparticles in aqueous environment, LaB〈sub〉6〈/sub〉@SiO〈sub〉2〈/sub〉 with a core-shell structure was successfully prepared. Both LaB〈sub〉6〈/sub〉 and LaB〈sub〉6〈/sub〉@SiO〈sub〉2〈/sub〉 demonstrated low cytotoxity in biomedical tests when their concentrations were limited to 0.2 mg mL〈sup〉−1〈/sup〉. The in vitro photothermal therapy experiment showed that 4T1 cancer cells were eventually apoptotic after being exposed to a 980 nm laser for 5 min at a considerably low power density of 0.82 W cm〈sup〉−2〈/sup〉 and a low dose of 0.1 mg mL〈sup〉−1〈/sup〉 for LaB〈sub〉6〈/sub〉@SiO〈sub〉2〈/sub〉. The results suggest that these LaB〈sub〉6〈/sub〉 nanospheres are viable photothermal agents for biomedical applications.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Anastasios Chalkidis, Deshetti Jampaiah, Patrick G. Hartley, Ylias M. Sabri, Suresh K. Bhargava〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The role of natural gas in mitigating greenhouse gas emissions and advancing renewable energy resource integration is undoubtedly critical. With the progress of hydrocarbons exploration and production, the target zones become deeper and the possibility of mercury contamination increases. This impacts on the industry from health and safety risks, due to corrosion and contamination of equipment, to catalyst poisoning and toxicity through emissions to the environment. Especially mercury embrittlement, being a significant problem in LNG plants using aluminum cryogenic heat exchangers, has led to catastrophic plant incidents worldwide. The aim of this review is to critically discuss the conventional and alternative materials as well as the processes employed for mercury removal during gas processing. Moreover, comments on studies examining the geological occurrence of mercury species are included, the latest developments regarding the detection, sampling and measurement are presented and updated information with respect to mercury speciation and solubility is displayed. Clean up and passivation techniques as well as disposal methods for mercury-containing waste are also explained. Most importantly, the environmental as well as the health and safety implications are addressed, and areas that require further research are pinpointed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309902-ga1.jpg" width="297" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Amanda Pereira da Costa Araújo, Nathalie Ferreira Silva de Melo, Admilton Gonçalves de Oliveira Junior, Fernando Postalli Rodrigues, Thiago Fernandes, Julya Emmanuela de Andrade Vieira, Thiago Lopes Rocha, Guilherme Malafaia〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Microplastics (MPs) are critical emerging pollutants found in the environment worldwide; however, its toxicity in aquatic in amphibians, is poorly known. Thus, the aim of the present study is to assess the toxicological potential of polyethylene microplastics (PE MPs) in 〈em〉Physalaemus cuvieri〈/em〉 tadpoles. According to the results, tadpoles’ exposure to MP PE at concentration 60 mg/L for 7 days led to mutagenic effects, which were evidenced by the increased number of abnormalities observed in nuclear erythrocytes. The small size of erythrocytes and their nuclei area, perimeter, width, length, and radius, as well as the lower nucleus/cytoplasm ratio observed in tadpoles exposed to PE MPs confirmed its cytotoxicity. External morphological changes observed in the animal models included reduced ratio between total length and mouth-cloaca distance, caudal length, ocular area, mouth area, among others. PE MPs increased the number of melanophores in the skin and pigmentation rate in the assessed areas. Finally, PE MPs were found in gills, gastrointestinal tract, liver, muscle tissues of the tail and in the blood, a fact that confirmed MP accumulation by tadpoles. Therefore, the present study pioneering evidenced how MPs can affect the health of amphibians.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310209-ga1.jpg" width="248" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 811〈/p〉 〈p〉Author(s): Miqi Wang, Zehua Zhou, Qijie Wang, Zehua Wang, Xin Zhang, Yuying Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉FeCrMoCBY amorphous coating with a high volume fraction of amorphous phase (90%) was prepared on Q235 steel by atmospheric plasma spraying. Influence of passivation potential on the corrosion resistance of passive films on the coating surface was estimated by electrochemical measurements, capacitance analysis, AFM and XPS technique. The results revealed that increasing potential promoted the growth of a more compact and thicker film due to the formation of more bounded water and oxides. Reduction in hydroxides further decreased point defects density significantly in the passive layer when passivated at a higher potential. A low diffusivity (1.67 × 10〈sup〉−15〈/sup〉 cm〈sup〉2〈/sup〉 s〈sup〉−1〈/sup〉) corresponding to point defects could suppress both the growth and degradation processes of passive film in chloride containing electrolyte, and thus enhance the film resistance to local thinning.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Ahmed Gamal El-Shamy〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Novel conductive PVA/CQDs nanocomposite films were synthesized through the casting technique for the electromagnetic (EM) wave protection at microwave band. The surface morphology, thermal and mechanical properties were briefly studied. The SEM micrograph showed an excellent distribution, dispersion and a high adhesion property of the CQDs in the PVA chains. Also, DSC analysis showed an increase in the〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈mtext〉glass〈/mtext〉〈mspace width="0.25em"〉〈/mspace〉〈mtext〉temperature〈/mtext〉〈mspace width="0.25em"〉〈/mspace〉〈mrow〉〈mo stretchy="true"〉(〈/mo〉〈msub〉〈mrow〉〈mi〉T〈/mi〉〈/mrow〉〈mrow〉〈mi〉g〈/mi〉〈mi〉l〈/mi〉〈mi〉a〈/mi〉〈mi〉s〈/mi〉〈mi〉s〈/mi〉〈/mrow〉〈/msub〉〈mo stretchy="true"〉)〈/mo〉〈/mrow〉〈/mrow〉〈/math〉 from 83.2 °C for fresh PVA to 95.4 °C for 8 wt% of CQD and the increase in melting temperature from 215 °C for fresh PVA to 227.7 °C for the same CQDs concentration. It was found that Young's modulus is directly proportional to CQD nano-particles concentration in the nano-composites from 0.14 GPa for fresh PVA to 4.48 GPa for 8 wt% of CQDs. It was found that the strength at break increases, but the elongation declines with the increase of CQDs nano-particles. The EM shielding effectiveness (SE) of (PVA/CQDs) nanocomposite is measured in the microwave frequency range, and it is found around 36.8 dB with the CQDs concentration (8 wt%). Finally, the PVA/CQDs nano-composite is of promising potential applications in electronics and microwave devices at an affordable cost.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819331846-fx1.jpg" width="148" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds〈/p〉 〈p〉Author(s): A. Rajabi, A.R. Mashreghi, S. Hasani〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, non-isothermal kinetic analysis of high temperature oxidation of Ti–6Al–4V alloy by thermogravimetric analysis (TGA) at heating rates of 10, 15, and 20 °C/min up to 1550 °C in air atmosphere was studied. The results revealed that the formed oxide layer consists of several different parts; an inner part of TiO〈sub〉2〈/sub〉, an outer part of TiVO〈sub〉4〈/sub〉, and an intermediate part of Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉. Also, the thickness of oxide layer increased by an increase in the maximum heating temperature, while its density decreased by formation of the pores and cracks in higher maximum temperature due to the mismatch between the thermal expansion coefficient of the oxide layer and the substrate. This mismatch led to formation of large stresses in the oxide layer at high temperatures (≥1000 °C) and thereby isolation of the oxide layer during cooling. The microhardness profiles shift to higher microhardness values by an increase in the maximum temperature due to the increasing of oxygen solubility in the substrate. On the other hand, the kinetic results performed by isoconversional Starink, KAS, FWO, Tang, and Friedman methods in combination with the invariant kinetic parameters (IKP) method and fitting model estimated the activation energy (〈em〉E〈/em〉) and pre-exponential factor (ln〈em〉A〈/em〉) of the oxidation process equal to 205–235 kJ/mol and 12-13 min〈sup〉−1〈/sup〉, respectively. Furthermore, it was approved that this reaction is controlled by a diffusion control model (D1 model).〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Yuejun Chen, Shizhen Zhu, Yanqi Ji, Zhuang Ma, Hengyong Wei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to avoid infrared emissivity deterioration of MoSi〈sub〉2〈/sub〉 particles result from its high-temperature oxidation, a satisfactory electrostatic self-assembly process was presented to synthesize MoSi〈sub〉2〈/sub〉@SiO〈sub〉2〈/sub〉 particles. A thermally stable and transmitting infrared SiO〈sub〉2〈/sub〉 shell was formed with tetraethyl orthosilicate (TEOS) as a precursor and tetrabutyl ammonium bromide (TBAB) as an electrostatic adsorbent after heat treatment at 1200 °C. The oxidation resistance, composition, micro-morphology and infrared emissivity of MoSi〈sub〉2〈/sub〉@SiO〈sub〉2〈/sub〉 were studied using thermogravimetric analysis, X-ray diffraction, energy disperse spectroscopy, scanning electron microscopy, and ultraviolet–visible near-IR spectrophotometer. The results demonstrated that MoSi〈sub〉2〈/sub〉 particle was thoroughly encapsulated by a SiO〈sub〉2〈/sub〉 glass shell, consequently, it exhibited great oxidation resistance compared with that of unencapsulated. More importantly, the emissivity of MoSi〈sub〉2〈/sub〉@SiO〈sub〉2〈/sub〉 particles had no obvious recession due to the intact encapsulation with TBAB. In addition, the electrostatic self-assembly mechanism of core-shell (MoSi〈sub〉2〈/sub〉@SiO〈sub〉2〈/sub〉) particles was discussed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Jingui Zong, Fei Wang, Guannan Liu, Mingshu Zhao, Sen Yang, Xiaoping Song〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Molybdenum disulfide (MoS〈sub〉2〈/sub〉), has aroused people's much research interest as an anode candidate for next generation of Li-ion batteries because of special layered structure and high theoretical capacity. However, MoS〈sub〉2〈/sub〉 suffers from a poor cycling stability and an inferior rate capability upon charge/discharge processes. So we have successfully synthesized a more stable expanded nanocomposite with superior electrical conductivity by intercalating moderate amorphous carbon between two adjacent S–Mo–S interlayer via a simple method which exhibits excellent lithium storage performance with high capacity (858.9 mA h g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉 for 1000 cycles), and superior rate capability (518 mA h g〈sup〉−1〈/sup〉 at 4 A g〈sup〉−1〈/sup〉). This superior electrochemical performance is attributed to the special structure (few layers, 2H phase, expanded interlayer spacing, amorphous carbon between S–Mo–S layers, C–O–Mo bond in the layer), small size and evenly distributed MoS〈sub〉2〈/sub〉 nanosheets. Besides, we study the 2H-1T phase transformation mechanism by controlling the ratio of ethylene glycol to water and O–C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O bond plays an important role in promoting 2H-1T phase transformation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Qinjiang He, Renli Fu, Xiufeng Song, Haitao Zhu, Xinqing Su, Chaoqun You〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, Ce〈sup〉3+〈/sup〉 and Ce〈sup〉3+〈/sup〉/Dy〈sup〉3+〈/sup〉 co-doped Ca〈sub〉3〈/sub〉Al〈sub〉2〈/sub〉O〈sub〉6〈/sub〉 phosphors have been designed and synthesized via a facile citrate-based sol-gel technique, and their structural, photoluminescence properties and energy transfer phenomenon were investigated comprehensively. The XRD analysis indicated that pure Ca〈sub〉3〈/sub〉Al〈sub〉2〈/sub〉O〈sub〉6〈/sub〉 phase can be synthesized at low temperature (1000 °C) for merely 2 h. The photoluminescence spectra showed the dominant emission of Ce〈sup〉3+〈/sup〉 singly doped phosphors is located in the blue region even at low Ce〈sup〉3+〈/sup〉 doping level, which indeed favors the energy transfer from Ce〈sup〉3+〈/sup〉 to other luminescent centers. When Dy〈sup〉3+〈/sup〉 is co-doped into Ca〈sub〉3〈/sub〉Al〈sub〉2〈/sub〉O〈sub〉6〈/sub〉:Ce〈sup〉3+〈/sup〉 phosphors, the remarkable sensitizing effect of Ce〈sup〉3+〈/sup〉 on Dy〈sup〉3+〈/sup〉 is validated by comparatively analyzing the excitation, emission spectra and average lifetimes of the series of samples. Through the concentration quenching theory, the critical distance between Ce〈sup〉3+〈/sup〉 and Dy〈sup〉3+〈/sup〉 is calculated to be 13.50 Å. Furthermore, the energy transfer mechanism between them is most likely ascribed to electric dipole-dipole interaction. In virtue of the variation of the emission intensities of Ce〈sup〉3+〈/sup〉 and Dy〈sup〉3+〈/sup〉, the emitting colors of Ca〈sub〉3〈/sub〉Al〈sub〉2〈/sub〉O〈sub〉6〈/sub〉:Ce〈sup〉3+〈/sup〉, Dy〈sup〉3+〈/sup〉 phosphors can realize tunable luminescence from deep blue to bluish-white region through controlling the Dy〈sup〉3+〈/sup〉 content. Based on these analysis, Ca〈sub〉3〈/sub〉Al〈sub〉2〈/sub〉O〈sub〉6〈/sub〉:Ce〈sup〉3+〈/sup〉, Dy〈sup〉3+〈/sup〉 phosphors could potentially be applied as a single-phase color-tunable phosphors pumped by near-ultraviolet (n-UV) radiation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Zhaohui Ma, Jiandong Zhang, Guoqing Yan, Hai Liu, Jingcun Huang, Lijun Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Thermodynamic properties of zirconium-oxygen (Zr–O) solid solution and its deoxidation by calcium in CaCl〈sub〉2〈/sub〉 molten salt were studied using a chemical equilibration technique. In the temperature range from 1173 to 1373 K, the equilibrium oxygen contents in Zr were measured experimentally under coexistence of Ca and CaO in CaCl〈sub〉2〈/sub〉 molten salt. The oxygen content in Zr was reduced from about 800 ppm to a minimum of less than 100 ppm. Then 〈em〉a〈/em〉〈sub〉CaO〈/sub〉 sensor — niobium-oxygen (Nb–O) solid solution was employed to equilibrate with Zr–O solid solution to determine the oxygen activity coefficient in Zr–O solid solution. Zr and Nb specimens were submerged in Ca-saturated CaCl〈sub〉2〈/sub〉 molten salt containing different amounts of CaO. CaCl〈sub〉2〈/sub〉 melt was used for a homogeneous reaction and composition. The experimental results shown that Henry's law held and the activity coefficient of oxygen was constant within the concentration range of this study. Based on the result, the standard formation Gibbs free energy of Zr–O solid solution was obtained as a function of temperature:〈span〉〈span〉1/2O〈sub〉2〈/sub〉 (g) = O (in Zr)〈/span〉〈/span〉〈span〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si17.svg"〉〈mrow〉〈mi〉Δ〈/mi〉〈msubsup〉〈mi〉G〈/mi〉〈mrow〉〈mi〉Z〈/mi〉〈mi〉r〈/mi〉〈mo linebreak="badbreak"〉−〈/mo〉〈mi〉O〈/mi〉〈/mrow〉〈mi〉θ〈/mi〉〈/msubsup〉〈mo linebreak="badbreak"〉=〈/mo〉〈mo linebreak="goodbreak"〉−〈/mo〉〈mn〉543577〈/mn〉〈mo linebreak="goodbreak"〉+〈/mo〉〈mn〉64〈/mn〉〈mtext〉.〈/mtext〉〈mn〉3〈/mn〉〈mi mathvariant="italic"〉T〈/mi〉〈mrow〉〈mo〉(〈/mo〉〈mtext〉1173−1373K〈/mtext〉〈mo〉)〈/mo〉〈/mrow〉〈/mrow〉〈/math〉〈/span〉〈/p〉 〈p〉The 〈em〉p-t-x〈/em〉 relationship of the deoxidation system was obtained simultaneously, which make the deoxidation limit and variation trend of oxygen content in Zr–O solid solution predictable and controllable under different conditions. Oxygen distribution coefficient between Zr–O solid solution and Nb–O solid solution was found in agreement with the theoretical value and independent of oxygen potential of the system.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Liang Ma, Shu-Shen Lyu, Yao Dai, Xian-Yinan Pei, Dong-Chuan Mo, Yuan-Xiang Fu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Transition metal oxide/reduced graphene oxide (TMO/RGO) composites have been explored for development as anode materials for lithium-ion batteries (LIBs); TMOs have high theoretical capacities, and the oxidation degrees of RGO sheets can directly affect the lithium storage performance of TMO/RGO composites. In this work, several NiO/reduced graphene oxide composites (NiO/RGO) are prepared based on oxidation degrees of graphite oxide sheets (GOs) through an ultrasonic agitation method. These composites are then explored as anodes for LIBs. Results show that the reversible capacity of NiO/RGO composites increases gradually to 1046 mA h/g and then declines to 956 mA h/g after 50 cycles at 100 mA/g. The variation rule of lithium storage properties of NiO/RGO samples can be attributed to the surface functional groups of RGO sheets, which can affect interfacial interaction between NiO and RGO sheets due to the different oxidation degrees of GO. Different RGO sheets also show distinct abilities to hinder NiO pulverisation and promote lithium-ion/electron diffusion during repeated charge and discharge processes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds〈/p〉 〈p〉Author(s): Kaixuan Chen, Shiwei Pan, Xiaohua Chen, Zidong Wang, Rolf Sandström〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The microstructure evolution in the as-cast pure Cu and Cu-(1.0–3.0)Fe-0.5Co and Cu-1.5Fe-0.1Sn (wt. %) alloys was characterised in the previous work. Herein, the plastic deformation characteristics were examined by uniaxial tensile tests at room temperature. Along with the microstructure evolution, the yield strength increased with increasing Fe content and reached a peak value at 1.5 wt % Fe, but thereafter decreased with the further addition of Fe in the Cu–Fe–Co alloys. Nevertheless, the tensile strength and elongation synchronously improve with increasing Fe content. In particular, the Cu-1.5Fe-0.1Sn alloy achieved the optimal strength–ductility combination. In terms of the strengthening mechanism, the (Fe, Co)- or (Fe, Sn)-doped copper encouraged impediment, trapping, and storage of dislocations by the iron-rich nanoparticles and grain boundaries, which enhanced the strength and sustained the work hardening and elongation. The evolution of mechanical properties under an alloying effect was quantitatively described by the strengthening models. The results indicate that the optimum balance between strength and ductility was achieved by designing a microstructure containing fine grains, intragranular smaller spherical nanoparticles, and a minor solute element with higher misfit and higher growth restriction effect. The necessities for engineering a microstructure to achieve simultaneously strong and ductile bulk metals were discussed.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819331500-fx1.jpg" width="443" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Natalia Pawlik, Barbara Szpikowska-Sroka, Tomasz Goryczka, Wojciech A. Pisarski〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the present paper, the nanocrystalline transparent oxyfluoride SrF〈sub〉2〈/sub〉:Eu〈sup〉3+〈/sup〉 glass-ceramic materials (nGCs) were synthesized via a low-temperature sol-gel method, in which trifluoroacetic acid (TFA) was used as a fluorination reagent. The thermal degradation of precursor xerogels was examined by TG/DSC analysis and the formation of SrF〈sub〉2〈/sub〉 nanocrystals inside silicate xerogel host was proved by XRD measurements. Additionally, to verify the structural changes within silicate network during ceramization process, the IR-ATR measurements were also carried out. The optical properties of Eu〈sup〉3+〈/sup〉 ions in precursor xerogels and fabricated nGCs were investigated based on photoluminescence excitation (PLE: λ〈sub〉em〈/sub〉 = 611 nm) and emission (PL: λ〈sub〉exc〈/sub〉 = 393 nm) spectra as well as luminescence decay analysis of the 〈sup〉5〈/sup〉D〈sub〉0〈/sub〉 excited level. It was observed, that for precursor silica xerogels the electric-dipole transition (ED) 〈sup〉5〈/sup〉D〈sub〉0〈/sub〉 → 〈sup〉7〈/sup〉F〈sub〉2〈/sub〉 was dominant, meanwhile the magnetic-dipole transition (MD) 〈sup〉5〈/sup〉D〈sub〉0〈/sub〉 → 〈sup〉7〈/sup〉F〈sub〉1〈/sub〉 had the greatest intensity for SrF〈sub〉2〈/sub〉:Eu〈sup〉3+〈/sup〉 nGCs. Thus, the R/O-ratio (R/O = I(〈sup〉5〈/sup〉D〈sub〉0〈/sub〉 → 〈sup〉7〈/sup〉F〈sub〉2〈/sub〉)/I(〈sup〉5〈/sup〉D〈sub〉0〈/sub〉 → 〈sup〉7〈/sup〉F〈sub〉1〈/sub〉)) was calculated to estimate the symmetry in the local framework around Eu〈sup〉3+〈/sup〉 ions. Moreover, the reddish-orange photoluminescence is long-lived (about 30-fold longer) for SrF〈sub〉2〈/sub〉:Eu〈sup〉3+〈/sup〉 nGCs compared with xerogels. The changes in emission spectra as well as double-exponential character of luminescence decay curves recorded for obtained nGCs indicated the successful migration of optically active Eu〈sup〉3+〈/sup〉 ions from amorphous silica framework to low phonon energy SrF〈sub〉2〈/sub〉 nanocrystal phase.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds〈/p〉 〈p〉Author(s): Ping Song, Wen-bin Li, Yu Zheng, Zhong-wei Guan, Xiao-ming Wang, Wen-xu Xu, Peng Ge〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The compressive and tensile stress–strain relationship and fracture behavior of a new low-cost titanium alloy Ti–5Al–3V–2Cr–2Fe (Ti–5322) at 286–573 K, a strain rate of 0.0001–4300 s〈sup〉−1〈/sup〉 and a stress triaxiality of 0.43–1.6 were studied. Based on the experimental data, the flow and fracture behavior of Ti–5322 was established based on the Johnson–Cook (J–C) equation. Ballistic impact tests were used to study the ballistic performance of a 7-mm-thick Ti–5322 target and the accuracy of the constitutive model was verified from the ballistic test results. The experimental results showed that the yield strength and strain rate of the Ti–5322 were related logarithmically. As the strain rate increased, the rate-strengthening behavior of the material weakened gradually. The material had an obvious thermal-softening behavior and the yield strength decreased linearly with an increase in deformation temperature. The stress triaxiality and strain rate had a significant effect on the fracture behavior of Ti–5322. The material fracture strain decreased with the stress triaxiality and an increase in strain rate. The J–C constitutive model was a good predictor for the ultimate penetration velocity of the Ti–5322 target and the velocity decay of fragments during penetration. The ballistic limit velocity of the 10-mm-diameter tungsten-alloy ball to the 7-mm-thick Ti–5322 target at 0° and 30° was 416.0 m/s and 484.8 m/s, respectively.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Dongqing Liu, Yimin Yin, Haifeng Cheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Transient memristor is highly desirable for secure memory system and secure neuromorphic computing. Here, a transient memristor with the MgO thin film as resistive dielectric material and the Ni as electrode material is reported. The memristor shows reversible and nonvolatile bipolar resistive switching performance, narrow distribution of low resistance state (LRS) and high resistance state (HRS), uniform switching voltages and stable retention at room temperature. It is indicated that the resistive switching mechanism of the memristor is conductive filament in LRS and space charge limiting current in HRS. In addition, the memristor can be failed after immersed in deionized water for 5 min due to the film damage resulting from large frizzle and the dissolution of Ni and MgO film. The prepared memristor has potential for secure memory system application.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Aihua Xu, Yi Wei, Qiancheng Zou, Wenyu Zhang, Yezi Jin, Zeyu Wang, Lizhen Yang, Xiaoxia Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, a new peroxymonosulfate (PMS) activation system was proposed employing nonredox metal ions as Lewis acids (LA), which have been widely recognized to play important roles in many biological and chemical oxidations. With Co〈sup〉2+〈/sup〉 ions as model catalysts, it was found that oxidizing power of PMS was enhanced after binding weak LA such as Ca〈sup〉2+〈/sup〉 ions, leading to its easier reduction to active radicals and substantial enhancement of dye degradation. The promoting effect of Ca〈sup〉2+〈/sup〉 was also observed with other cobalt catalysts including CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 and Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉. The rate of PMS decomposition in Co〈sup〉2+〈/sup〉+LA/PMS system was correlated with Lewis acidity; while in the presence of strong LA including La〈sup〉3+〈/sup〉 and Y〈sup〉3+〈/sup〉, the dye degradation rate declined. The interactions of LA with PMS were characterized and the detailed mechanism was proposed. The present study provides the first example of the promoting effect of weak LA on PMS activation with cobalt based catalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310350-ga1.jpg" width="361" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Zhiwen Lei, Jianwen Feng, Yu Yang, Jinlai Shen, Weide Zhang, Chaoyang Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Zeolitic imidazolate frameworks (ZIFs) possess tremendous potential in various adsorption and catalysis areas for their particular structures. However, the dispersibility and acid stability of ZIFs are important issues hindering their applications. To address these challenges, a transparent polydimethysiloxane (PDMS) coating was constructed to heterogeneously anchor the Cu doped ZIF-67 (Cu/ZIF-67) nanoparticles on melamine sponge surface, achieving a PDMS-coated ZIF three-dimensional composite sponge. Thus PDMS coating could also effectively protect ZIFs from acid damage to prolong the service life of photocatalyticity. It was demonstrated that the composite sponges were able to repeatedly (over 40 cycles) degrade Sudan I dyes with remarkable photocatalytic efficiency (〉97%). More importantly, the ion impenetrability of PDMS coating made the ZIFs based composite a longer term catalytic life than unprotected Cu/ZIF-67 under acid condition. Incidentally, due to the introduction of rough ZIFs and hydrophobic PDMS coating, the obtained sponge also exhibits super-hydrophobicity (158.5°), great compressibility and excellent oil/acid water separation performance. We expect that such a polymer coating strategy could act as a novel inspiration for extending the applications and life span of ZIF-based composites.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉MF-ZIF-67@PDMS sponge shows an efficient photocatalytic activity for lipophilic Sudan I degradation under acid conditions and excellent oil/acidic water separation.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310118-ga1.jpg" width="264" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Lei Zhang, Shan Ji, Rongfang Wang, Dan J.L. Brett, Hui Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A flexible cathode with highly electrochemical performance for bendable supercapacitors have been achieved by electrochemical depositing hierarchical nanostructured Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/Ni(OH)〈sub〉2〈/sub〉 compounds on the surface of commercial conductive textile. The morphology and physical properties of as-prepared electrode are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS). Based on its unique nanostructure, the obtained flexible Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/Ni(OH)〈sub〉2〈/sub〉 electrode exhibits a highly electrochemical capacitance of 1800 F g〈sup〉−1〈/sup〉 at 3 mA cm〈sup〉−2〈/sup〉 with good rate capability, excellent stability and bendability. Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/Ni(OH)〈sub〉2〈/sub〉 electrode as cathode is assembled with active carbon as anode and PVA/KOH as electrolyte into an asymmetric capacitor to evaluate its performance in a real supercapacitor. The obtained supercapacitor cell delivers a high energy density of 0.49 mWh cm〈sup〉−2〈/sup〉 at 3.54 mW cm〈sup〉−2〈/sup〉 and maintains the energy density at 0.38 Wh cm〈sup〉−2〈/sup〉 when power density increases to 21.53 mW cm〈sup〉−2〈/sup〉. When the assembled cells are connected in series, these connected cells can work safely and properly at a much higher voltage window due to their good stability and consistency. Considering its low-cost, facile fabrication and highly electrochemical performance, the obtained Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/Ni(OH)〈sub〉2〈/sub〉 electrode is a promising flexible material.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881933110X-fx1.jpg" width="255" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Runchen Jia, Weidong Zeng, Shengtong He, Xiongxiong Gao, Jianwei Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fracture toughness and fracture mechanism of Ti60 alloy with duplex microstructure under different temperature conditions were investigated in the present work. The experimental result shows that the fracture toughness of CT samples increases from the room temperature (40  MPa m〈sup〉1/2〈/sup〉) to 400 °C (71.45  MPa m〈sup〉1/2〈/sup〉) but declines at 600 °C (62.55  MPa m〈sup〉1/2〈/sup〉). It is observed from fracture surface through SEM that the predominant fracture mechanism has changed from quasi-cleavage fracture at room temperature to ductile fracture at higher temperatures. In addition, the tortuosity of crack propagation path has a limited impact on the fracture toughness. Path selections for crack propagation are obtained through SEM observation which can be summarized as: cut through lamellar 〈em〉α〈/em〉, parallel to lamellar 〈em〉α〈/em〉, bypass the equiaxed 〈em〉α〈/em〉〈sub〉〈em〉p〈/em〉〈/sub〉 and cut through the equiaxed 〈em〉α〈/em〉〈sub〉〈em〉p〈/em〉〈/sub〉. Moreover, it is found that the intrinsic contribution is the primary reason leading to the change of the fracture toughness of Ti60 alloy under different temperatures. Meanwhile, it is noteworthy that the area of the crack tip plastic zone increases from RT to 400 °C but decreases at 600 °C, which is seen as the main impact of temperature on fracture toughness. To be exact, the CT sample with a larger area of the plastic zone could provide a higher 〈em〉K〈/em〉〈sub〉〈em〉1C〈/em〉〈/sub〉 value. Furthermore, a prediction model of 〈em〉K〈/em〉〈sub〉〈em〉1C〈/em〉〈/sub〉 based on tensile properties is established, which has a good accuracy with experimental results. The model is useful in predicting the fracture toughness of Ti60 alloy at different test temperatures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Shuying Dong, Longji Xia, Fangyuan Zhang, Fengzi Li, Yuyao Wang, Lingfang Cui, Jinglan Feng, Jianhui Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The ZnSn(OH)〈sub〉6〈/sub〉 nanocubes were prepared under different pH (3–12.4) by liquid precipitation, well characterized and further used for wastewater treatment. The results indicated that the ZnSn(OH)〈sub〉6〈/sub〉 nanocubes prepared at pH = 11.1 possessed of uniform size distribution and excellent photocatalytic activity, the degradation efficiency to MB reaches 76.3% after 5 h natural sunlight irradiation. Subsequently, the prepared ZnSn(OH)〈sub〉6〈/sub〉 nanocubes was further thermal treated (200 °C, 24 h) in four different solvents, containing deionized water, stock solution, mixed solution (V〈sub〉water〈/sub〉: V〈sub〉ethanol〈/sub〉: V〈sub〉glacial acetic acid〈/sub〉 = 3:1:1) and ethanol, named as H-1, H-2, H-3 and H-4, respectively. H-2 and H-3 showed superior photocatalytic performance and the removal efficiency of MB improved to be almost 100%, as well as red-shifted light absorption edge and the band gap energies reduced 0.9 and 0.93 eV, respectively. Moreover, free radical capture experiments showed that the h〈sup〉+〈/sup〉 and ·O〈sub〉2〈/sub〉〈sup〉−〈/sup〉 are the main active species for the ZnSn(OH)〈sub〉6〈/sub〉 nanocubes and H-2, respectively, while all these three ·OH, ·O〈sub〉2〈/sub〉〈sup〉−〈/sup〉 and 〈sup〉1〈/sup〉O〈sub〉2〈/sub〉 radicals for H-3. Those results suggested that both pH regulation and thermal treatment could efficiently improve the microscopic morphology, crystal structure and photocatalytic activity of the ZnSn(OH)〈sub〉6〈/sub〉, which might pave the way for the artful design of other high-performance catalysts.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838819332013-fx1.jpg" width="312" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Zhen Zhang, Jing Liu, Fenghua Shen, Yuchen Dong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The temporal influence of reaction atmosphere and chlorine on arsenic release in combustion, gasification and pyrolysis of sawdust was studied using an on-line analysis system. The arsenic release amount in combustion atmosphere was higher than that in CO〈sub〉2〈/sub〉 gasification and argon pyrolysis. The derived values of activation energy followed the order: combustion 〈 gasification 〈 pyrolysis. Furthermore, the enhancement effect of chlorine species on arsenic release percentage in air combustion was also higher than that in gasification and pyrolysis conditions. The total proportion of arsenic release in combustion with additive chlorine is bigger than the case in gasification and pyrolysis, especially when 20% chlorine is added. According to equilibrium analysis, arsenic oxides were identified as the main gaseous arsenic species and their formation were decreased in the oxygen-deficient environment, mainly accounting for lesser arsenic release proportion in gasification and pyrolysis than combustion. The release of arsenic was promoted to a different extent with additive chlorine, mainly caused by the AsCl〈sub〉3〈/sub〉 (g) formation. By the findings of the experiments and theoretical analyses, the possible reaction pathways and release mechanisms of arsenic species were proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310015-ga1.jpg" width="479" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Daniel Ociński, Piotr Mazur〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The hybrid polymer obtained by entrapment of Fe-Mn waste oxides from water deironing into a chitosan matrix was evaluated as an As(III) and As(V) sorbent. Its maximum adsorption capacity determined from a Langmuir isotherm model was 44.17 mg As(III)/g or 26.80 mg As(V)/g and 50.73 mg As(III)/g or 82.99 mg As(V)/g under neutral and acidic conditions, respectively. The pH markedly influenced the efficiency and the rate of As(V) adsorption, whereas its impact on As(III) removal was slight. The sorbent was simply regenerated using NaOH solution, and no drop in adsorption capacity was observed after 6 cycles. The physical form and the durability of the sorbent enabled continuous work in a fixed-bed system without clogging of the bed. Arsenic concentration in the effluent exceeded 0.01 mg As/L only after passing about 2700 bed volumes. Arsenates formed surface complexes with iron oxides and were bounded by the imine groups of cross-linked chitosan. Arsenites were oxidized by MnO〈sub〉2〈/sub〉 before adsorption but, because of the low Mn:Fe ratio, a fraction of them were also directly bound to the iron oxides, especially at neutral pH. The conducted studies confirmed the usability of the examined material as a highly efficient sorbent for arsenic removal from water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310167-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Bor-Shuang Liaw, Ting-Ting Chang, Haw-Kai Chang, Wen-Kuang Liu, Po-Yu Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, low-cost and eco-friendly hydroxyapatite (HA) minerals were extracted from scales of Tilapia fish (〈em〉Oreochromis mossambicus〈/em〉). After calcination, fish-scale extracted powder was further confirmed to be HA by X-ray diffraction with mean particle size of 5.96 μm determined by particle size analyzer. The calcined powder was utilized as the raw material and combined with chitosan (CS) to synthesize composite scaffolds by freeze casting and cross-linking. Mercury porosimetry results showed that the scaffolds possessed hierarchical porous structure. Microstructural features characterized by SEM revealed unidirectional channel structures with channel sizes ranged from 10 to 100 μm and 1 to 50  μm for scaffolds freeze-casted at 2 ℃/min and 5 ℃/min cooling rates, respectively. The adsorption kinetics of HA/CS composite scaffolds with varying channel sizes were investigated by both batch and fixed-bed processes with different Pb(П) initial concentrations (100 and 1000 mg/L). The adsorption capability was optimized by tuning the cooling rates and the maximum adsorption amount could reach 75–570 mg/g in batch process and 94 mg/g in fixed bed process. In summary, the HA/CS composite scaffolds showed great capability to remove heavy metal ions from waste water and their tunable channel sizes could be applied in suitable fields under both statistic and flowing conditions.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Pyeong-Koo Lee, Min-Ju Kang, Youn-Joong Jeong, Yi Kyun Kwon, Soonyoung Yu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As-contaminated soil samples were chosen to identify As sources near a Zn smelter where Zn contamination in soils was found to be of smelter origin. Based on the As concentrations and Pb isotopic compositions, high As levels in soils were originated from the geogenic source. There was no consistent trend in As concentrations with either depth or distance from the smelter, while the Pb isotopic compositions in soils varied regardless of As levels and were quite different from those of smelter origin. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) suggested that the high As concentrations were due to arsenopyrite and its alteration minerals, which were easily found but heterogeneously distributed within host rocks. A detailed investigation of As levels and Pb isotropic compositions along the predominant wind direction also supported that the As contamination was of geogenic origin unlike the Zn contamination. The atmospheric emissions from the smelter increased the Zn concentrations and decreased the 〈sup〉206〈/sup〉Pb/〈sup〉207〈/sup〉Pb ratios at surface layers, while the As concentrations occasionally exceeded the worrisome level at deep layers. According to the Pb isotropic compositions, about 21% of the As-contaminated soils were impacted by the smelter, in particular at the surface layer.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Shouqiang Huang, Liang Li, Nanwen Zhu, Ziyang Lou, Weiqiao Liu, Jiehong Cheng, Haoming Wang, Pengxuan Luo, Hui Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The high concentration of chloride (Cl〈sup〉−〈/sup〉) ions in leachate often has negative effects in their harmless treatments, and the common treatments containing the ion exchange method consume excessive antichlors due to their large particle sizes and unfavorable morphologies. Herein, the antichlors of the Bi(III) containing oxides with quantum dots (QDs) or two-dimensional (2D) structures are first explored for the removal and recovery of Cl〈sup〉−〈/sup〉 ions in concentrated leachate. By using the QDs/2D flakes constructed antichlors of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and the magnetite Bi-Ti composite, the maximum Cl〈sup〉−〈/sup〉 removal rates of 61.8% and 66.1% are respectively achieved under the optimum conditions. The higher removal efficiency of the magnetite Bi-Ti composite is contributed by its less stable crystal phases of Bi〈sub〉25〈/sub〉FeO〈sub〉40〈/sub〉/Bi〈sub〉12〈/sub〉TiO〈sub〉20〈/sub〉, which can proceed more deeply in the removal of Cl〈sup〉−〈/sup〉 ions compared with that of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉. The recovered terminal magnetite Bi-Ti precipitate with Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/BiOCl heterostructure exhibits excellent photocatalytic activity in the degradation of the dechlorinated leachate, where a total organic carbon removal rate of 87.2% is achieved under UV–vis-near-infrared irradiation. Therefore, the selection of Bi(III) containing oxides opens a promising and high-value method for the removal and recovery of Cl〈sup〉−〈/sup〉 ions in leachate and other waste waters.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309951-ga1.jpg" width="261" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Jingwen Pan, Baoyu Gao, Wen Song, Xing Xu, Qinyan Yue〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effective managements of organic solid waste and surface water eutrophication can reuse/reduce solid waste resources, and ensure surface water safety. Herein, an easily-recoverable amine-functionalized biosorbent was developed from biogas residue (BR-N) for nitrate and phosphate removals from surface water. Physicochemical characteristics revealed that BR-N has a cross-staggered structure with abundant quaternary-amine groups to enhance the diffusion and electrostatic attraction of nitrate/phosphate. In batch studies, nitrate/phosphate could be effectively removed by the BR-N within a wide pH range of 5.0-9.0, and the maximum adsorption capacities of BR-N were 64.12 mg/g for nitrate and 34.40 mg P/g for phosphate. After continuous 8 cycles of adsorption-desorption, BR-N still exhibited 〉82% adsorption capacity for nitrate/phosphate removals, implying the high chemical stability and reusability for water treatment. Whereafter, BR-N has real application prospect in water treatment, which could effectively treat ˜380, ˜260 and ˜760 bed volumes (BV) of three actual eutrophic surface water to satisfy the surface water standard of China (GB3838-2002). The cost of BR-N was 2.89 $/kg evaluated by energy-economy assessment, indicating the low-cost production of biogas residue-based adsorbent for treating eutrophic surface water. Overall, this study provides a new idea for high-value utilization of organic solid waste and purification of eutrophic water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310271-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Yaoping Hu, Zhijin Gao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Million tons of sewage sludge produced yearly creates a severe pollution problem to environment, and thus needs either to be properly disposed of, or recovered. Here, we demonstrate a value-added utilization of sewage sludge by converting its contained organics into nanosized carbon dots (CDs) with microwave irradiation. This synthetic method, using waste resources as precursors and avoiding the requirement of hazardous reagents and complex procedures, has the great advantage of low cost, environmental friendliness, and easy scalability. The resultant CDs exhibit excellent fluorescence properties with a large quantum yield (QY) of up to 21.7%, higher than the most values of waste-derived CDs. It is found that CDs can serve as a sensitive and selective sensor to detect para-nitrophenol (p-NP), a toxic pollutant, through fluorescence quenching, giving a linear detection range of 0.2–20 μM and a detection limit of as low as 0.069 μM. Systematic investigations suggest that the inner filter effect (IFE) is the dominant sensing mechanism. Moreover, the practical applications of CDs for p-NP assay in real water samples achieve good results.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310027-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Sewage sludge as a renewable resource toward highly fluorescent carbon dots for sensing of para-nitrophenol through inner filter effect.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Kun Wu, Dongdong Chen, Shaoyou Lu, Jianzhang Fang, Ximiao Zhu, Fan Yang, Tao Pan, Zhanqiang Fang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Developing inexpensive and stable photocatalysts without noble metals, yet remarkably enhancing the photocatalytic activities, is highly needed. Here, a novel carbon and cerium co-doped porous g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (C/Ce-CN) has been successfully prepared through thermal polymerization of the supramolecular aggregation. The morphologies, chemical structures, optical and photoelectrochemical properties of the synthesized photocatalysts were analyzed via a series of characterization measurements. Experimental results indicated that C/Ce-CN showed remarkably enhanced photocatalytic activity of TC and RhB degradation, which is about 2.6 and 2.4 times higher than that of pristine CN, and it also exhibited a good stability. Compared with bare CN, the enhanced performance of C/Ce-CN is mainly attributed to the stronger utilization rate of visible light, the rapider charge transfer rate, the longer lifetime of carriers and the larger surface specific area. The main intermediates in degradation process of antibiotics were tested by the HPLC-MS. Finally, the possible photocatalytic degradation pathways and mechanisms were proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309811-ga1.jpg" width="286" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Zhuo Li, Zhenyang Yu, Changzheng Cui, Fangting Ai, Daqiang Yin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Increasing concerns are earned on the multigenerational hazards of antibiotics due to the connection between their mother-children transfer via cord blood and breast milk and obesity in the children. Currently, 〈em〉Caenorhabditis elegans〈/em〉 was exposed to sulfamethoxazole (SMX) over 11 generations (F0–F10). Indicators of obesogenic effects and gene expressions were measured in each generation and also in T11 to T13 that were the offspring of F10. Biochemical analysis results showed that SMX stimulated fatty acids in most generations including T13. The stimulation was resulted from the balance between enzymes for fatty acid synthesis (e.g., fatty acid synthetase) and those for its consumption (e.g., fatty acid transport protein). Gene expression analysis demonstrated that the obesogenic effects of SMX involved peroxisome proliferator activated receptors (PPARs, e.g., 〈em〉nhr-49〈/em〉) and insulin/insulin-like signaling (IIS) pathways (e.g., 〈em〉ins-1〈/em〉, 〈em〉daf-2〈/em〉 and 〈em〉daf-16〈/em〉). Further epigenetic analysis demonstrated that SMX caused 3-fold more H3K4me3 binding genes than the control in F10 and T13. In F10, the most significantly activated genes were in metabolic and biosynthetic processes of various lipids, nervous system and development. The different gene expressions in T13 from those in F10 involved development, growth, reproduction and responses to chemicals in addition to metabolic processes.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Mingmei Ding, Wei Chen, Hang Xu, Zhen Shen, Tao Lin, Kai Hu, Chun hui Lu, Zongli Xie〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The development of non-cobalt-based heterogeneous catalysts with efficient catalytic activity, good stability and nontoxicity is very important for the application of peroxymonosulfate-based advanced oxidation processes (AOPs) in water treatment. In this work, with two dimensional MXene as the catalyst substrate, a novel α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/MXene (FM) nanocomposite was fabricated through a facile solvothermal method. Systematic characterization demonstrated that the MXene substrate could facilitate the size reduction and good dispersion of α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles. The FM nanocomposite achieved high efficiency and stability towards activating peroxymonosulfate (PMS) to produce free radicals for the degradation of salicylic acid (SA) in aqueous solution. The operating parameters, including catalyst dosage, PMS dosage, SA concentration and initial pH value, were evaluated and analysed. The co-existence of sulfate radicals (SO〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈sup〉—〈/sup〉) and hydroxyl radicals (〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉OH) was confirmed using electron paramagnetic resonance spectroscopy and radical scavenger tests, while SO〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈sup〉—〈/sup〉was identified as the main reactive species in the FM/PMS catalytic system. The possible mechanisms for the electron transfer and radical generation during the process of PMS activation by the FM nanocomposite are further investigated using XPS and in situ Raman analysis. The results provide an avenue for rationally constructing and developing alternative catalysts for the treatment of organics in wastewater.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310180-ga1.jpg" width="256" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Long Peng, Lei Li, Qinhao Lin, Mei Li, Guohua Zhang, Xinhui Bi, Xinming Wang, Guoying Sheng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A single particle aerosol mass spectrometry (SPAMS) was deployed to investigate the mixing state and chemical processing of Pb-rich particles in suburban Beijing. Based on a large dataset of mass spectra, Pb-rich particles were classified into Pb-O-Cl-N-S (55%), Pb-N (17%), Pb-N-S (15%), and Pb-EC (7%). Residual coal combustion, industrial activities, and meteorological conditions were identified as main factors regulating the variations of Pb-rich particles in the atmosphere. The highest abundance of the Pb-rich particles was observed during heating period (HP) primarily due to the increase in coal usage. Pb in Pb-O-Cl-N-S type was identified in forms of PbO, PbCl〈sub〉2,〈/sub〉 and Pb(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉. Dominantly presented in the form of Pb(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉, Pb-N type represented the completely transformed Pb-rich particles from PbO/PbCl〈sub〉2〈/sub〉 by atmospheric processes. It is found that PbCl〈sub〉2〈/sub〉 and PbO could be transformed to Pb(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉, highly dependent on the amount of NO〈sub〉2〈/sub〉 and RH. Significant enhancement of nitrate in Pb-O-Cl-N-S particles was observed when the RH was greater than 60%, emphasizing the importance of heterogeneous hydrolysis of N〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 on the formation of Pb(NO〈sub〉3〈/sub〉)〈sub〉2.〈/sub〉 Compared with non-carcinogenic PbCl〈sub〉2〈/sub〉/PbO and insoluble PbO, soluble and carcinogenic Pb(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉 produced by atmospheric processes may significantly enhance negative effects of Pb-rich particles on human health and the ecosystem.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309689-ga1.jpg" width="481" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Qiulai He, Jianyang Song, Wei Zhang, Shuxian Gao, Hongyu Wang, Jian Yu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Aerobic granular sludge-based simultaneous nitrification, denitrification and phosphorus removal (SNDPR) systems were configured for the treatment of low-strength municipal wastewater. Granular characteristics, process performance, and the corresponding microbial ecology dynamics were comprehensively explored with sodium acetate and succinate as mixed carbon source. Results revealed that aerobic granules kept structural and functional resilience, while mixed carbon source largely altered and balanced the growth and competition of phosphorus/glycogen accumulating organisms (PAOs/GAOs). Appropriate ratio of mixed carbon source was vital for superb physiochemical behaviors and reliable removal performance by aerobic granules. Therefore, the aerobic granular SNDPR system could achieve deep-level nutrients removal through enhancing the anaerobic carbon uptake rate and strengthening the carbon usage efficiency. The present work could add some guiding sight into the application of aerobic granular SNDPR system for wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309975-ga1.jpg" width="244" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Ronghua Mu, Yanhui Ao, Tengfei Wu, Chao Wang, Peifang Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉 loaded anatase-TiO〈sub〉2〈/sub〉 (B) biphase nanowires composite photocatalysts were fabricated by an in situ calcination method and exhibited outstanding photocatalytic activity. The microstructure, optical performance and band structure of the composite photocatalysts were investigated by relevant characterizations. The results demonstrated the successful formation of heterojunction between anatase-TiO〈sub〉2〈/sub〉 (B) biphase nanowires and Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉, which integrated the advantages of homojunction and heterojunction. Therefore, it definitely improved separation efficiency of photo-induced electron-holes because of the formation of multi-junctions. In order to test the enhanced photocatalytic activity, acetaminophen was chosen as target pollutant. The sample with 67% Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉 (TiO〈sub〉2〈/sub〉-Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉-3) presented the highest photocatalytic activity on the degradation of acetaminophen and its reaction apparent rate constant was 10 and 25 times as that of Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉 biphase nanowires, respectively. Through trapping experiments and LC–MS/MS analysis, O〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉H was proved to be the key active specie during the photocatalytic process of acetaminophen degradation〈strong〉. Meanwhile〈/strong〉 a possible degradation pathway was proposed based on the detected intermediate products.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Juan Xiao, Chuan Wang, Hong Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fenton-like degradations of dimethyl phthalate (DMP) and phenolic compounds (phenol, catechol, resorcinol, and hydroquinone) in single and binary systems were investigated by focusing on the Fe(III)/Fe(II) redox cycle during the reaction processes. Quinone-like substances were generated and found to be responsible for the autocatalytic transformation of Fe(III) to Fe(II) in the Fenton-like process with DMP or phenolics. Moreover, phenolic compounds could accelerate the Fenton-like degradation of DMP, with an increased efficiency of H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 utilization. The effect of phenolic compounds on the degradation of DMP followed the order: catechol ≈ hydroquinone 〉 resorcinol 〉 phenol, which could be attributed to the interaction between quinone-like substances and iron ions. Hydroquinone-like substances accelerated the Fe(III)/(II) redox cycle. The formation of iron complexes between catechol-like substances and iron ions facilitated the release of H〈sup〉+〈/sup〉 and regeneration of Fe(II). In addition, a plausible mechanism for enhanced Fenton-like degradation of DMP by phenolics was proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309616-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Min-Hua Cui, Thangavel Sangeetha, Lei Gao, Ai-Jie Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding the electrode configuration is vital for the successful application of bioelectrochemical system (BES) in recalcitrant wastewater treatment. Especially in those traditional anaerobic processes that integrate with BES to construct effective hybrid bioreactors. Hybrid bioreactors employed granular graphite as electrode material achieved 86.62 ± 1.83% decolorization efficiency of azo dye acid orange 7 (AO7) at influent AO7 loading rate of 800 g/(m〈sup〉3〈/sup〉∙d) and it was about 6% higher than that with carbon fiber brush electrodes. Such electrodes were positioned above the anaerobic sludge layer and higher efficiency (8%) than the reactors with electrodes placed beneath the sludge layer was observed. Tracer experiments and modeling of residence time distribution indicated that the fluid pattern in hybrid bioreactors was modified to plug flow pattern and had a better consummate mixing ability compared to the conventional anaerobic reactor. Simulation using computational fluid dynamics technique showcased favorable mass transfer near electrode modules. The hydrodynamics of simulation and experimental results were connected by simplifying electrode module as a porous media model. This study thus proved that hybrid bioreactors can effectively enhance wastewater treatment comprehensively through the analysis of decolorization performance and hydrodynamics.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Libing Chu, Dan Chen, Jianlong Wang, Zhilin Yang, Qi Yang, Yunpeng Shen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In present work, the degradation of antibiotic and inactivation of antibiotic resistance genes (ARGs) in cephalosporin C fermentation (CEPF) residues were performed using ionizing radiation, ozonation and thermal treatment. The results showed that the three treatment methods could degrade cephalosporin C effectively, with the removal efficiency of 85.5% for radiation at dose of 100 kGy, 79.9% for ozonation at dosage of 5.2 g O〈sub〉3〈/sub〉/L, and 71.9% and 87.3% for thermal treatment at 60 °C and 90 °C for 4 h. The cephalosporin resistance gene tolC was detected in the raw CEPF residues, and its abundance was decrease 74.2% by radiation, 64.6% by ozonation and 26.9%–37.1% by thermal treatment respectively. The presence of protein, glucose and acetate in the CEPF residues had inhibitive influence on the degradation of cephalosporin C by ionizing radiation, and the effect was more significant when the antibiotic concentration was lower. The total content of COD, polysaccharides and protein changed slightly after radiation and thermal treatment, while they were decreased greatly by ozonation. The primary techno-economic analysis showed that the operational cost of ionizing radiation by electron beam at 50 kGy ($5.2/m〈sup〉3〈/sup〉) was comparable to thermal treatment ($4.3–7.9/m〈sup〉3〈/sup〉), which was more economical than ozonation ($14.6/m〈sup〉3〈/sup〉).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941931012X-ga1.jpg" width="336" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 19 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Jianhua Yuan, Yao Ma, Fei Yu, Yiran Sun, Xiaohu Dai, Jie Ma〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The recovery of nitrogen (N) and phosphorus (P) from wastewater is of great importance in addressing the global nutrient crisis. The limitations of existing methods require the development of effective technology. Here, two different hydrogel adsorbents were fabricated with good separation ability for metal cation (M〈sup〉+〈/sup〉) and metal anion (M-) but showed little removal of nutrients. Based on the materials, a novel three-stage operation system combining adsorption and capacitive deionization (CDI) technology was presented for nutrient recovery and wastewater treatment. In the first two stages, mixed metals in wastewater were successfully separated (Cu〈sup〉2+〈/sup〉: 144.6 mg/g; Cr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉〈sup〉2−〈/sup〉: 167.0 mg/g), and nutrients were retained (N and P 〈 1 mg/g). In the third stage, the residual trace metal ions in the solution were removed (2.0 mg/L to N/A), and the nutrients were enriched through electroadsorption and desorption processes by CDI. Plants using recovered liquid fertilizers revealed similar values for height, root length, and chlorophyll compared with those obtained using actual fertilizers. The results indicated that this novel three-stage operation system (3S A-C system) combining adsorption and CDI is efficient in recovering liquid fertilizers from wastewater and is a promising technology for simultaneously addressing nutrient crises and environmental pollution.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309938-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Three-stage operation system (3S A-C system) combining adsorption and CDI is efficient in recovering liquid fertilizers from wastewater and is a promising technology for simultaneously addressing nutrient crises and environmental pollution.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Yating Luo, Binhui Ye, Jien Ye, Jingli Pang, Qiao Xu, Jingxuan Shi, Bibo Long, Jiyan Shi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Some ions in soils may affect the growth and metabolism of microorganisms and subsequently alter the remediation efficiency of Cr(VI). Here, the effects of different Ca〈sup〉2+〈/sup〉 and SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 levels on the reduction of Cr(VI) by 〈em〉Penicillium oxalicum〈/em〉 SL2 were investigated. The results showed that Cr(VI) reduction by 〈em〉P. oxalicum〈/em〉 SL2 in potato dextrose liquid (PDL) medium was accelerated by the presence of exogenous Ca〈sup〉2+〈/sup〉 and SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉. The Cr(VI) reduction rates were increased by 52.5% (200 mg L〈sup〉−1〈/sup〉 Ca〈sup〉2+〈/sup〉 treated) and 55.9% (2000 mg L〈sup〉−1〈/sup〉 SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 treated), respectively. High concentration of Ca〈sup〉2+〈/sup〉 in medium resulted in the production of calcium oxalate crystals, which was contributed to the adsorption of chromium. In addition, X-ray absorption near-edge spectroscopy (XANES) analysis showed that 〈em〉P. oxalicum〈/em〉 SL2 could reduce the toxicity of Cr(VI) by synthesizing cysteine (Cys) and reduced glutathione (GSH). The decrease of thiol compounds (Cys and GSH) in 〈em〉P. oxalicum〈/em〉 SL2 mycelia treated with SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 proved the alleviation of oxidative stress. In conclusion, exogenous Ca〈sup〉2+〈/sup〉 could reduce the damage of Cr(VI) to 〈em〉P. oxalicum〈/em〉 SL2 by maintaining the integrity of cell wall, and the addition of SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 alleviated the Cr(VI) toxicity to 〈em〉P. oxalicum〈/em〉 SL2, thus accelerating the reduction of Cr(VI).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941931026X-ga1.jpg" width="479" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 25 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 810〈/p〉 〈p〉Author(s): Dongdong Zhang, Qiang Yang, Kai Guan, Baishun Li, Nan Wang, Pengfei Qin, Bo Jiang, Chi Sun, Xin Qin, Zheng Tian, Zhanyi Cao, Jian Meng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A high-strength low-rare-earth-alloyed Mg−3.5Sm−2Yb−0.6Zn−0.4Zr alloy was processed by an ingot metallurgy process with hot-extrusion followed by artificial aging. The peak-aged sample exhibited a higher yield strength of 449 MPa than most of extruded Mg−Gd based alloy containing high RE content, and even is comparable to that of the T8-treated 2024 Al alloy. The studied alloy exhibited a typical bimodal microstructure, consisting of dynamically recrystallized (DRXed) grains with random textures and coarse unrecrystallized regions with strong basal fiber texture. In addition, the fragmented Mg〈sub〉5〈/sub〉RE and Mg〈sub〉41〈/sub〉RE〈sub〉5〈/sub〉 phases distributed at extrusion stringers. Abundant of fine Mg〈sub〉3〈/sub〉RE particles precipitated dynamically in DXRed regions, which restrains DRXed grains growth effectively by grain boundary pinning. Within the unDXRed regions, uniformly dense Mg〈sub〉3〈/sub〉RE and Mg〈sub〉12〈/sub〉RE nano-precipitates were observed. Also there were many basal 〈〈strong〉a〈/strong〉〉 dislocations and a few non-basal 〈〈strong〉c〈/strong〉 + 〈strong〉a〈/strong〉〉 dislocations in unDXRed regions. Subsequent artificial ageing significantly enhanced the alloy's strength by introducing basal precipitates, although decreased the ductility slightly. Finally, the ultrahigh yield strength was revealed to be attributed to the combined effects of a strong basal fiber texture, a bimodal microstructure, and numerous precipitated particles.〈/p〉〈/div〉 〈/div〉