ALBERT

Description: 〈p〉Publication date: 10 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 296〈/p〉 〈p〉Author(s): Saheed Bukola, Stephen E. Creager〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Transmission rates for protons and deuterons across single-layer graphene embedded in Nafion | graphene | Nafion sandwich structures are measured as a function of temperature in electrochemical hydrogen pump cells. Rates of ion transmission through graphene are obtained in the form of area-normalized ion-transfer resistances, and are interpreted in terms of ion-exchange current densities and standard heterogeneous ion-transfer rate constants. An encounter pre-equilibrium model for the ion-transfer step is then used to provide rate constants for the fundamental microscopic step of ion (proton or deuteron) transmission across graphene. Application of this rate model to interpret variable-temperature data on proton and deuteron transmission rates provides values for the activation energy and pre-exponential factor for the fundamental ion transmission step across graphene. Activation energies obtained from the Arrhenius plots for proton and deuteron transmission are as follows; for proton, E〈sub〉act〈/sub〉 = 48 ± 2 kJ/mole (0.50 ± 0.02 eV) and for deuteron, E〈sub〉act〈/sub〉 = 53 ± 5 kJ/mole (0.55 ± 0.05 eV). The difference between these two values of approximately 5 kJ/mole is in good agreement with the expected difference in vibrational zero-point energies for O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H and O-D bonds, albeit with some uncertainty given the uncertainties in the activation energy values. Pre-exponential frequency factor values of 8.3 ± 0.4 × 10〈sup〉13〈/sup〉 s〈sup〉−1〈/sup〉 and is 4.7 ± 0.5 × 10〈sup〉13〈/sup〉 s〈sup〉−1〈/sup〉 were obtained for proton and deuteron transmission respectively across graphene. These pre-factor values are both quite large, on the order of the values predicted from the Eyring – Polanyi equation with a transmission coefficient near one. The ratio of 1.8 for the rate pre-factors (H/D) is in reasonable agreement with the value of 1.3 for the ratio of bond vibrational frequencies for O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H and O-D stretching, respectively. Taken together, these data support a model in which proton and deuteron transmission across graphene are largely adiabatic processes for which the differences in transmission rate at room temperature are due largely to differences in activation energies.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 295〈/p〉 〈p〉Author(s): Kaili Jin, Man Zhou, Hong Zhao, Shixiong Zhai, Fengyan Ge, Yaping Zhao, Zaisheng Cai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the large theoretical capacity and environmental benignity, copper sulfide (CuS) becomes a prospective candidate electrode material for supercapacitors. In this work, electroconductive mesoporous carbonized clothes (Cc) was obtained by carbonizing the waste cotton fabrics. Then the CuS was galvanostatic electrodeposited on 〈em〉Cc〈/em〉 to prepare the binder-free 〈em〉g〈/em〉-CuS/Cc electrode. In the galvanostatic electrodeposition process, CuS grew along the crystal surface to form regular nanosheets, and a part of Cu〈sup〉2+〈/sup〉 were reduced to Cu〈sup〉1.1+〈/sup〉. In addition, on account of the synergistic effect of electrochemical double layer capacitance with pseudocapacitance and the high specific surface area (450.76 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉), the 〈em〉g〈/em〉-CuS/Cc composite displayed not only outstanding areal specific capacitance (4676 mF cm〈sup〉−2〈/sup〉 at 2 mA cm〈sup〉−2〈/sup〉) but also excellent cycling performance (89.8% retention after 10000 cycles). Meanwhile, the symmetrical flexible supercapacitor (SC) based on 〈em〉g〈/em〉-CuS/Cc electrodes with PVA-KOH gel electrolyte (〈em〉g〈/em〉-CuS/Cc-SC) accomplished a high specific capacitance of 1333 mF cm〈sup〉−2〈/sup〉 at 2 mA cm〈sup〉−2〈/sup〉 as well as ultrahigh energy density of 0.96 Wh cm〈sup〉−2〈/sup〉 at the power density of 4.36 W cm〈sup〉−2〈/sup〉. Therefore, 〈em〉g〈/em〉-CuS/Cc shows a great potential for applications in the next generation of flexible energy storage devices.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618324447-fx1.jpg" width="384" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 295〈/p〉 〈p〉Author(s): Kang Li, Zhanwei Xu, Xuetao Shen, Kai Yao, Jianshe Zhao, Ronglan Zhang, Jun Zhang, Li Wang, Jianfeng Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Commercial lithium/thionyl chloride (Li/SOCl〈sub〉2〈/sub〉) batteries cannot meet the 3.15 V platform required for most instruments. A 〈em〉hovenia acerba〈/em〉-like assembly constructed with cobalt tetrapyridinoporphyrazine of thickness of 5–15 nm is anchored on acid-functionalized multi-walled carbon nanotubes (CoTAP/MWCNTs), which were prepared using an 〈em〉in situ〈/em〉 solid synthesis process. The discharge time of Li/SOCl〈sub〉2〈/sub〉 batteries with a voltage greater than 3.15 V catalyzed by CoTAP/MWCNTs is found to be 11 min longer than batteries without catalysts and 4 min longer than those catalyzed by CoTAP alone. The energy of Li/SOCl〈sub〉2〈/sub〉 batteries with a voltage greater than 3.15 V catalyzed by CoTAP/MWCNTs is discovered to be 11.44-times higher than batteries with AF-MWCNTs and 6.17-times higher than those catalyzed by bulk CoTAP. This is due to the fact that more CoTAP ultrafine nanoparticulates are anchored on the AF-MWCNTs. These nanoparticulates provide more active sites for the catalytic reaction of SOCl〈sub〉2〈/sub〉. The assemblies are shown to have an adsorption-coordination effect on Li ions and to delay the deposition of lithium chloride passive films enhancing battery voltage platforms.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉A 〈em〉hovenia acerba〈/em〉-like assembly constructed with cobalt tetrapyridinoporphyrazine of thickness of 5–15 nm is anchored on acid-functionalized multi-walled carbon nanotubes (CoTAP/MWCNTs), which were prepared using an 〈em〉in situ〈/em〉 solid synthesis process. The discharge time of Li/SOCl〈sub〉2〈/sub〉 batteries with a voltage greater than 3.15 V catalyzed by CoTAP/MWCNTs is found to be 11 min longer than batteries without catalysts and 4 min longer than those catalyzed by CoTAP alone.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618324319-fx1.jpg" width="270" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): S. Monzani, A. Andreazza, M. Citterio, P. Fontana, M. Ianna, T. Lari, V. Liberali, F. Ragusa, C. Sbarra, A. Sidoti, A. Stabile〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Monochromatic X and gamma rays are a standard calibration tool for semiconductor detector. For finely segmented pixel detectors, like the ones foreseen for HL-LHC detector upgrades, the single pixel spectrum is affected by charge sharing across nearby pixels, due to diffusion and the finite range of photoelectrons, resulting in a low energy continuum below the photoelectric peak. In this paper a systematic simulation study will be presented. The shape of the transition between the photoelectric peak and the continuum is determined by diffusion and needs to be unfolded for a correct estimation of the energy resolution. Simulation results are compared with data collected with different high-resistivity CMOS devices with 50 × 250 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi mathvariant="normal"〉μ〈/mi〉〈/math〉m〈sup〉2〈/sup〉 pixel size and photon energies between 13 and 60 keV. They show a good agreement, highlighting the potential usage of the whole single pixel spectrum to derive device characteristics.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Xinjiang Hu, Weixuan Wang, Guangyu Xie, Hui Wang, Xiaofei Tan, Qi Jin, Daixi Zhou, Yunlin Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel ternary composite of graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉)/graphene oxide (GO) sheets/BiFeO〈sub〉3〈/sub〉 (CNGB) with highly enhanced visible-light photocatalytic activity toward Cr(VI) photoreduction is prepared and characterized. The characterization and photocatalysis experiments corroborate its reasonable band gap, efficient charge separation and transfer, widened visible-light adsorption, easy solid-liquid separation, good stability and superior catalytic activity of CNGB. Three CNGB samples with different ratios of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and BiFeO〈sub〉3〈/sub〉 (CNGB-1, -2, -3 with 2:4, 3:3, and 4:2, respectively), though possessing different adsorption ability, eventually remove all Cr(VI) ions via photocatalysis within 90 min. The catalytic efficiency of the composite is the highest at pH 2; increases in pH decrease the catalytic ability. The inorganic anions such as SO〈sub〉4〈/sub〉〈sup〉−〈/sup〉, Cl〈sup〉−〈/sup〉, and NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 only slightly affects the photocatalytic process. The matching of the band structure between BiFeO〈sub〉3〈/sub〉 and g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 generates efficient photogenerated electron migration from the conduction band of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 to that of BiFeO〈sub〉3〈/sub〉, which is also facilitated by the electron bridging and collecting effects of GO, and holes transfer from the valence band of BiFeO〈sub〉3〈/sub〉 to that of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, yielding the efficient separation of photogenerated electron-hole pairs and the subsequent enhancement of photocatalytic activity. The research provides a theoretical basis and technical support for the development of photocatalytic technologies for effective application in wastewater treatment and Cr-contaminated water restoration.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): F. Faghihzadeh, N.M. Anaya, H. Hadjeres, T.B. Boving, V. Oyanedel-Craver〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉This study present assessed the effect of UV pulsed light (PL) on microbial and organic pollutants using two spiral lamps were used, i.e., PL1 and PL2 lamps, with wavelength cut-offs of 190 and 240 nm, respectively. Overall, our study demonstrated that pulsed UV light impacts several microbial biomolecules and degrades polycyclic aromatic hydrocarbons (PAHs) in aqueous solution. In microbial inactivation by PL2, temporary changes of bacterial cellular components, specifically proteins, were observed, but the compositional changes of bacteria that were exposed to PL1 were permanent due to ozonolysis. PL1 irradiation caused greater deactivation of the bacteria than PL2 irradiation due to the generation of ozone. The higher efficacy of PL1 in terms of membrane disruption, reduction of respiration rate, and reduction of growth rate was due to the production of ozone during the irradiation period. The bacteria that were irradiated with both PL lamps regrew due to photoreactivation, such as an enzymatic DNA-repair mechanism.〈/p〉 〈p〉The PAH degradation kinetics indicate that higher molecular weights degraded faster than those with lower molecular weights. For both lamps, the degradation of naphthalene and fluorene was first order, whereas second order for pyrene and anthracene. Any effect of ozonolysis on the PAH degradation rates was not apparent, which indicated that photolysis was the primary degradation pathway. PAH solutions treated with both pulsed UV lamps did not result in a toxicity effect on the bacteria.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Yaquan Liu, Xinyue Pang, Jiarui Song, Xinhe Liu, Juanjuan Song, Yongna Yuan, Chunyan Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Decabromodiphenyl ethane (DBDPE) is widely used in industry as an alternative to the decabromodiphenyl ether (BDEs). The large-scale use of DBDPE could lead to rapid growth of the human accumulation level of DBDPE. However, the biophysics of accumulation of DBDPE in cell membranes, as one of determinants of DBDPE metabolism is not clear. In the present study, detailed observations of cell lactate dehydrogenase (LDH) and reactive oxygen species (ROS) levels measurements proved that the DBDPE exposure to cell could result in significant cell membrane damage by concentration-dependent manners. The fluorescence anisotropy analysis supported the evidence that high concentration DBDPE bound decreased membrane fluidity significantly. Besides it, a detailed molecular dynamic (MD) simulation was approached to investigate the effects of DBDPE on the DPPC (dipalmitoyl phosphatidylcholine) phospholipid bilayer, which was constructed as the model of cell membrane. The molecular dynamic simulation revealed that DBDPE molecules can easily enter the membrane from the aqueous phase. Under the concentration of a threshold, the DBDPE molecules tended to aggregate inside the DPPC bilayer and caused pore formation. The bound of high concentration of DBDPE could result in significant variations in DPPC bilayer with a less dense, more disorder and rougher layer. The knowledge about DBDPEs interactions with lipid membranes is fundamentally essential to understand the in vivo process of DBDPE and the physical basis for the toxicity of DBDPE in cell membranes.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320010-fx1.jpg" width="457" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Yangke Long, Sifan Bu, Yixuan Huang, Yueqi Shao, Ling Xiao, Xiaowen Shi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Metal-free carbo-catalyst has recently emerged as a promising candidate as a substituent for tradition-metal based heterogeneous catalyst for catalytic activation of peroxymonosulfate (PMS). However, most reported carbo-catalysts suffer from low catalytic efficiency and poor stability, thus a high-performance catalyst is urgently desired. In this study, a novel carbo-catalyst (NHPC-800), prepared by using tannic acid and dicyandiamide as renewable carbon/nitrogen feedstocks via a simple pyrolysis route, is reported as an activator of PMS with highly efficient catalytic ability and stability. The as-prepared NHPC-800 possesses as high as 22.4 atom% of nitrogen dopants and a hierarchically porous structure with abundant meso/macropores, accompanied by the abundant edges and wrinkles, which supply sufficient exposed catalytically active centers and fast electrons/mass transportations. Using rhodamine B as a model pollutant, the NHPC-800 shows a highly efficient catalytic ability which is superior to most reported carbo-catalysts and even some state-of-the-art metal catalysts. Based on competitive quenching experiments and electron paramagnetic resonance (EPR) results, a non-radical pathway involving the generation of 〈sup〉1〈/sup〉O〈sub〉2〈/sub〉 is responsible for the degradation of pollutants. Given that the NHPC-800 shows good recycling performance and strong resistance to adventitious interference such as anions and natural organic matters, we believe NHPC-800 can be a promising candidate for practical applications, and this study can provide inspirations for the further development of highly efficient carbo-catalysts.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320460-fx1.jpg" width="343" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 25 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 147〈/p〉 〈p〉Author(s): Jan Seiler, Franz Lanzerath, Christoph Jansen, André Bardow〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Efficient evaporation of water at low temperatures is challenging due to its low saturation pressure. As a consequence, the preferred evaporation by nucleate boiling can only be achieved at the cost of high superheats. However, low superheats can still lead to efficient evaporation by thin-film evaporation. In this work, we experimentally characterize the heat transfer for thin-film evaporation on coated copper tubes, which use capillary action to create a thin film on their surface. The overall heat transfer through the tubes is determined at all filling levels for evaporator inlet temperatures of 10, 15 and 20 °C with varied driving force. Our experiments reveal that poor coatings suffer from dry-out at high driving forces whereas tubes with good coatings remain fully wetted even at high driving force. Furthermore, we show the impact of surface properties on thin-film evaporation: high porosity, surface extension and roughness promote the creation of a thin film on the tube. Thereby, the heat transfer 〈em〉UA〈/em〉-value is increased up to a factor of 10.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 147〈/p〉 〈p〉Author(s): Jianxin Xu, Qingtai Xiao, Zhihan Lv, Junwei Huang, Ruoxiu Xiao, Jianxin Pan, Hua Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We propose a new method to measure uniformity of gas-liquid mixing in a direct-contact heat exchanger by moment balance and image analysis. A mapping technique is developed to project the pixels distribution from binary image to 3D domain. We present a rigorous theoretical base of the applied method based on moments and equilibrium theory. An inclination angle with direction is derived to characterize the imbalanced structure caused by heterogeneity of mass distribution, which is used to quantify the global uniformity of spatial distribution of mixtures in any irregular area. A characteristic curve obtained by local inclination angles can be used to test the homogeneous, heterogeneous and pseudo-homogeneous mixtures, leading to a useful parameter to quantify the mixing effects. The uniformity obtained by similar patterns are compared with existing methods. The experimental results show a good fitting curve between mixing effects and heat transfer performance. This test could also be applied for studying a variety of multiphase mixing problems in which assessment of uniformity is required.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 295〈/p〉 〈p〉Author(s): Shuxing Wu, Hengzhi Guo, Kwan San Hui, Kwun Nam Hui〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Rational electrode architectural design, favorable electrode composition, and versatile synthesis approach play a significant role in developing advanced electrodes for high-performance supercapacitor. In this work, we report a facile approach for fabricating 1D hierarchical CuO@Co〈sub〉〈em〉x〈/em〉〈/sub〉Ni〈sub〉〈em〉1−x〈/em〉〈/sub〉(OH)〈sub〉2〈/sub〉 nanowire arrays grown on 3D highly conductive copper foam. The optimized CuO@Co〈sub〉0.2〈/sub〉Ni〈sub〉0.8〈/sub〉(OH)〈sub〉2〈/sub〉 electrode delivers an ultrahigh specific capacity of 374.7 mAh g〈sup〉−1〈/sup〉 at 2 A g〈sup〉−1〈/sup〉 with exceptional rate capability (301.7 mAh g〈sup〉−1〈/sup〉 at 50 A g〈sup〉−1〈/sup〉) and remarkable cycling stability (95.9% after 10 000 cycles at 50 A g〈sup〉−1〈/sup〉). A flexible asymmetric solid-state supercapacitor (ASC) is fabricated using the optimized CuO@Co〈sub〉0.2〈/sub〉Ni〈sub〉0.8〈/sub〉(OH)〈sub〉2〈/sub〉 as the positive electrode, activated carbon-coated nickel foam as the negative electrode, and polyvinyl alcohol/KOH gel as electrolyte. The flexible ASC operating with a potential window of 0–1.6 V delivers an energy density of 46.5 Wh kg〈sup〉−1〈/sup〉 with a power density of 526.9 W kg〈sup〉−1〈/sup〉. The ASC also exhibits excellent cycling stability with a capacity retention of 84.3% after 10 000 cycles at a current density of 7 A g〈sup〉−1〈/sup〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618324459-fx1.jpg" width="325" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 295〈/p〉 〈p〉Author(s): Krishnan Shanmugam Anuratha, Hsiao-Shan Peng, Yaoming Xiao, Tzu-Sen Su, Tzu-Chien Wei, Jeng-Yu Lin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this current work, a bifunctional TiO〈sub〉2〈/sub〉 thin film with reduced pin-hole effect and enhanced light trapping capability was successfully fabricated by using a facile galvanostatic anodic deposition route in the presence of Brij-58 soft template (ST). The surface morphology of electrodeposited TiO〈sub〉2〈/sub〉 thin film using ST confirmed the formation of nano-sized TiO〈sub〉2〈/sub〉 particles with improved porous nature than that of TiO〈sub〉2〈/sub〉 thin film electrodeposited in the absence of ST. Compared with the conventional scaffold porous layer (PL) fabricated from commercial mesoporous TiO〈sub〉2〈/sub〉 composed of ∼30 nm nanoparticles, the electrodeposited TiO〈sub〉2〈/sub〉 film using ST demonstrated the reduced pinhole effect and improved light trapping feature. Owing to the bifunctional behavior of electrodeposited TiO〈sub〉2〈/sub〉 using ST, the cell efficiency of the perovskite solar cell was achieved up to 17.06% which was ca.10% higher than those with commercial TiO〈sub〉2〈/sub〉 nanoparticles.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): K. Dropiewski, A. Minns, M. Yakimov, V. Tokranov, P. Murat, S. Oktyabrsky〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Picosecond timing of energetic charged particles and photons is a challenge for many high-energy physics and medical applications. InAs Quantum Dots (QDs) embedded in GaAs matrix are expected to have singular scintillation properties. The advantages come from highly efficient energy conversion, as well as from fast electron capture and radiative recombination in QDs. We present design considerations and demonstration of an ultrafast, high photon yield room-temperature semiconductor scintillator. Due to the high refractive index of GaAs, the scintillator is fabricated in the form of a 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mn〉20〈/mn〉〈mspace width="1em"〉〈/mspace〉〈mi mathvariant="normal"〉μ〈/mi〉〈mi mathvariant="normal"〉m〈/mi〉〈/math〉 thick planar waveguide with an integrated InGaAs photodiode. QD luminescence of about 60% efficiency at room temperature has been shown, and modal attenuation stabilized at 1 cm〈sup〉−1〈/sup〉. Scintillation responses from 5.5 MeV alpha particles show an extremely fast decay time of 280 ps, a collection efficiency of 11% and a time resolution of 60 ps. This data confirms the unique potential properties of this scintillation detector.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Nicole S.M. Vieira, Joana C. Bastos, Luís P.N. Rebelo, Ana Matias, João M.M. Araújo, Ana B. Pereiro〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The use of fluorinated ionic liquids (FILs) as novel materials in biological and pharmaceutical applications is an emerging research field. The knowledge of their cytotoxicity and that of 1-octanol/water partition coefficients are essential to assess their environmental risks, to estimate their toxicity and activity, or the hydrophilic/lipophilic balance, as well as to explore their properties as solvents in extraction processes or for successful drug design. The study of the cytotoxicity in four different human cell lines and the experimental measurement of the partition coefficient between 1-octanol and water (P〈sub〉〈em〉o/w〈/em〉〈/sub〉), using the slow-stirring method, were carried out for several FILs. In both studies, the effect of the cation ([C〈sub〉2〈/sub〉C〈sub〉1〈/sub〉Im]〈sup〉+〈/sup〉, [C〈sub〉2〈/sub〉C〈sub〉1〈/sub〉py]〈sup〉+〈/sup〉, [C〈sub〉4〈/sub〉C〈sub〉1〈/sub〉pyr]〈sup〉+〈/sup〉, [N〈sub〉1112(OH)〈/sub〉]〈sup〉+〈/sup〉, or [N〈sub〉4444〈/sub〉]〈sup〉+〈/sup〉), the cationic alkyl side-chain length ([C〈sub〉n〈/sub〉C〈sub〉1〈/sub〉Im]〈sup〉+〈/sup〉, with n = 2, 6, 8 or 12), and the anionic fluorinated chain length/anionic fluorinated domain size ([C〈sub〉4〈/sub〉F〈sub〉9〈/sub〉SO〈sub〉3〈/sub〉]¯, [C〈sub〉8〈/sub〉F〈sub〉17〈/sub〉SO〈sub〉3〈/sub〉]¯, or [N(C〈sub〉4〈/sub〉F〈sub〉9〈/sub〉SO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉]¯) were analysed. The results reveal that both toxicity and partition properties are mainly influenced by the size of the cationic hydrogenated alkyl side-chain and that of the anionic fluorinated domain. The intrinsic tuneability of the FILs allows for their selection according to the lipophilic or hydrophilic character of the target biological system under consideration. The toxicity studies corroborate the biocompatible nature of some FILs tested in this work. Along, for all the FILs under study P〈sub〉〈em〉o/w〈/em〉〈/sub〉 〈 1.00. Accordingly, a decadic logarithm of the bioconcentration factor in fish of 0.5 would be estimated, which is below the regulatory endpoint used by regulatory agencies.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320204-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Yasir Aziz, Ghulam Abbas Shah, Muhammad Imtiaz Rashid〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, there is a growing interest among agriculturists to use nanotechnology for the development of nutrient-use efficient fertilizers. However, its sustainable use for the synthesis of mineral or organic nano-fertilizers requires a thoughtful of the mechanism as well as the fate of nutrients and their interaction with soil-plant systems. Therefore, the aim of current study was to investigate the mixing of three different application rates of zinc oxide nanoparticles (ZNPs: 1.4, 2.8 and 3.6 mg kg〈sup〉−1〈/sup〉 soil) as well as zeolite (141, 282 and 423 mg kg〈sup〉−1〈/sup〉 soil) with biogas slurry (AS) on soil nutrient availability and herbage nitrogen (N) and zinc (Zn) uptake in a standard pot experiment. We found that both ZNPs and zeolite significantly increased mineral N content in soil compared to AS alone (P 〈 0.05). On the other hand, plant available phosphorus or potassium and microbial biomass carbon (C) in the soil were neither significantly affected by any application rate of ZNPs nor zeolite mixed AS. Soil microbial biomass N was significantly higher in second and third application rates of both ZNPs and zeolite amended AS treatments compared to AS alone. However, this increment in mineral N did not influence shoot uptake and herbage apparent recovery of this nutrient from AS. Similarly, co-mixing of both ZNPs and zeolite in AS did not influence shoot N uptake but Zn uptake was significantly higher in this treatment compared to AS alone. Therefore, this combination would be considered for improving crop Zn uptake under such fertilizer management regimes.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518319805-fx1.jpg" width="357" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Roya Nazari, Ljiljana Rajić, Ali Ciblak, Sebastián Hernández, Ibrahim E. Mousa, Wei Zhou, Dibakar Bhattacharyya, Akram N. Alshawabkeh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study investigates the effect of palladium (Pd) form on the electrochemical degradation of chlorobenzene in groundwater by palladium-catalyzed electro-Fenton (EF) reaction. In batch and flow-through column reactors, EF was initiated via in-situ electrochemical formation of hydrogen peroxide (H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉) supported by Pd on alumina powder or by palladized polyacrylic acid (PAA) in a polyvinylidene fluoride (PVDF) membrane (Pd-PVDF/PAA). In a mixed batch reactor containing 10 mg L〈sup〉−1〈/sup〉 Fe〈sup〉2+〈/sup〉, 2 g L〈sup〉−1〈/sup〉 of catalyst in powder form (1% Pd, 20 mg L〈sup〉−1〈/sup〉 of Pd) and an initial pH of 3, chlorobenzene was degraded under 120 mA current following a first-order decay rate showing 96% removal within 60 min. Under the same conditions, a rotating Pd-PVDF/PAA disk produced 88% of chlorobenzene degradation. In the column experiment with automatic pH adjustment, 71% of chlorobenzene was removed within 120 min with 10 mg L〈sup〉−1〈/sup〉 Fe〈sup〉2+〈/sup〉, and 2 g L〈sup〉−1〈/sup〉 catalyst in pellet form (0.5% Pd, 10 mg L〈sup〉−1〈/sup〉 of Pd) under 60 mA. The EF reaction can be achieved under flow, without external pH adjustment and H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 addition, and can be applied for in-situ groundwater treatment. Furthermore, the rotating PVDF-PAA membrane with immobilized Pd-catalyst showed an effective and low maintenance option for employing Pd catalyst for water treatment.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320046-fx1.jpg" width="341" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 21 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 915〈/p〉 〈p〉Author(s): Jingyu Tang, Changdong Deng, Xi Wu, Shuai Li, Yuwen Wu, Wen Kang, Xiyin Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper presents the design and prototyping of novel structure magnets–simplified multipole magnets, one octupole and one dodecapole. The field measurements of the prototypes show very good agreement with the numerical field calculations. The octupole prototype can produce either an anti-symmetric or a symmetric field distribution. Magnets with this novel structure can supply much higher saturation fields, e.g. doubled pole-gap strength of 0.6 T for the dodecapole prototype. The intrinsic field errors for the integrated field distribution are within 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si15.gif"〉〈mo〉±〈/mo〉〈/math〉1% for a rectangular shape of good field region, which are acceptable for some applications such as beam spot uniformization. Some key technical issues of building the magnets are also discussed. The success of the prototyping will pave the way for applications of the magnet family.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Noriaki Kawaguchi, Go Okada, Kentaro Fukuda, Takayuki Yanagida〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have tested high-temperature responses of prototype neutron detectors equipping Ce-doped lithium silicate glass (GS20), LiCaAlF〈sub〉6〈/sub〉:Ce, LiCaAlF〈sub〉6〈/sub〉:Eu, LiCaAlF〈sub〉6〈/sub〉:Ce, Na, and LiCaAlF〈sub〉6〈/sub〉:Eu, Na. These detectors were prepared by coupling of the scintillators to a photomultiplier tube (PMT) for high-temperature environments (R1288, Hamamatsu). In the pulse height spectra under thermal neutron irradiation in the temperature range from 25 °C to 150 °C, peak heights of all the samples decreased with increasing temperatures. The decreasing rates for the peak heights of LiCaAlF〈sub〉6〈/sub〉 scintillators were lower than that of GS20. The LiCaAl〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉F〈/mi〉〈/mrow〉〈mrow〉〈mn〉6〈/mn〉〈/mrow〉〈/msub〉〈/math〉scintillators can be used in the temperature range from 25 °C to 150 °C.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): A. Loi, A. Lai, G.F. Dalla Betta, R. Mendicino, S. Vecchi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The experimental conditions in future High Luminosity LHC experiments require new detector systems with increased performances compared to the current state of the art. In this context, increasing spacial resolution and including time measurement with a resolution of less than 50 ps for particle tracking systems can avoid false track reconstruction due to event pile up. For this kind of future tracking detectors the 3D silicon sensor technology appears as a good option. In this context the TIMESPOT initiative was launched. Concerning the development of the sensor, different geometrical solutions have been explored and simulated to optimize the timing response of the single pixel sensor using Sentaurus TCAD. The configuration with the best electric field characteristics for timing was selected for signal simulation. In order to compensate the very time-consuming behavior of TCAD simulations, a faster charge transport simulator with TCAD and Geant4 support is under development. Further sensor configurations, including a first primitive capacitive and resistive load, were also simulated and evaluated. This paper shows a general overview of the project with particular attention to the silicon sensor development. First results are presented.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 913〈/p〉 〈p〉Author(s): S. Mehdi Hashemi, Ali Negarestani〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, the performance of two GEM-type structures for the detection of alpha particle tracks in gaseous detectors based on SQS mode is presented. The operation of these structures was investigated in the presence of air, pure argon and P10 gas. By increasing the applied voltage to GEM-type plates beyond a certain value, each GEM-type’s through-hole individually entered to the SQS mode, when detector operated in the P10 gas. This mode was followed by the appearance of visible streamers in the space of holes exposed to alpha radiation. Two types of Thick Gas Electron Multipliers (TGEM) and Electron Multiplier Assemblies (EMA) with different geometries, as well as a cascade configuration of EMAs, were designed and constructed. Depending on the hole diameters in these structures, the location of the input beams can be determined optically with a specific resolution.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): G. Silvestre, on behalf of FOOT collaboration〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The goal of the FOOT (FragmentatiOn Of Target) experiment is to measure the fragmentation cross section of protons into H, C, O targets at beam energies of interest for hadrontherapy (50–250 MeV for protons and 50–400 MeV/u for Carbon ions) (Tommasino et al., 2015 [1]; FOOT CDR Conceptual Design, 0000 [2]). Given the short range of the fragments, an inverse kinematic approach has been chosen, hence requiring precise tracking capabilities for charged ions. One of the foreseen experiment subsystems will be the MSD (Microstrip Silicon Detector), composed of three 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉x〈/mi〉〈/math〉–〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈mi〉y〈/mi〉〈/math〉 measuring planes. In this work we evaluate the suitability of standard double-sided microstrip detectors, coupled to an high dynamic range readout chip, to be used for this task. The results about cluster signal, signal/noise, and dynamic range of readout chip are encouraging, and confirm the suitability of this class of sensors to be used in the FOOT experiment.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 919〈/p〉 〈p〉Author(s): Xiurong Li, Huihai He, Gang Xiao, Xiong Zuo, Shaohui Feng, Lingyu Wang, Cong Li, Mohsin Saeed, Zhen Cao, Xiangdong Sheng, Ning Cheng, for the LHAASO collaboration〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, novel methods are presented to measure the optical properties of the cylindrical water Cherenkov detector with high-reflectivity and diffuse reflection dominated Tyvek material as the inner surface. The mean transmission distance of photons between each reflection in the cylindrical water Cherenkov detector (the mean step length), is constant when there is a sufficient number of photons with random directions in the tank. The time distribution of the photons collected by the photomultiplier tube (PMT) in the water Cherenkov detector is approximately exponential, and the decay factor of the time distribution is determined by the absorption length of photons in the water, the reflectivity of the inner Tyvek surface, the mean step length of photons reflected in the tank, and the ratio of reflective Tyvek area to the total inner surface area. By considering the principles of photon propagation in the water Cherenkov detector, we developed novel methods to measure the water absorption length, Tyvek reflectivity, and mean step length of photons in the tank. The water absorption length and Tyvek reflectivity can be measured simultaneously by changing the height of the water, while the step length and Tyvek reflectivity in air can be measured simultaneously by changing the area of Tyvek, and the mean step length of photons can also be measured even all other parameters unknown. The proposed novel methods are supported by the deduction of formulae and verified by GEANT4 simulations and the prototype experiment.〈/p〉〈/div〉

Description: 〈p〉Publication date: 25 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 147〈/p〉 〈p〉Author(s): Olga Arsenyeva, Julian Tran, Mark Piper, Eugeny Kenig〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Pillow-plate heat exchangers (PPHEs) represent a novel equipment type. For their application in industry, reliable preliminary design techniques are required. In this article, the existing methods for heat exchangers design are analysed and the approach for selecting the PPHE design with minimal heat transfer area is proposed. It is based on the mathematical model of thermal and hydraulic PPHE behaviour, in which the overall heat transfer coefficient and pressure drop in PPHEs are expressed through the fluid velocity. The estimation of fluid velocities in PPHE channels is based on the condition that the predefined allowable pressure drop is fully exploited. Two case studies for water heating and crude oil preheat train operating conditions are discussed, in which the flowrates of the fluids on the hot and cold sides differ significantly. The PPHE design with minimal heat transfer area for the considered case studies is presented, with specified pillow-plate geometry parameters and distance between pillow-plate panels. The resulting pressure drops and velocities in PPHEs channels as well as the obtained heat transfer surface areas are compared with existing data for chevron-type plate heat exchangers (PHEs) designed for the same operating conditions. This comparison shows that PPHEs have higher velocities in channels, longer plates and lower heat transfer area. It can be concluded that PPHEs can be successfully used for operating conditions, under which the flow rates for hot and cold fluid are significantly different and the application of chevron-type PHEs with single-pass arrangement is complicated.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Mengmeng Liu, Min Zhang, Rongjie Hao, Tingting Du, Tong Li, Yao Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Graphene oxide (GO) is a structural analog of graphene and contains numerous O-containing functional groups. As rapidly increasing production and usage of GO, it is inevitable to flow into the water and wastewater treatment system and finally oxidized by disinfectants to form DBPs. Meanwhile, as GO is a nano sized carbon material, it may also break the human digestion system when it was absorbed by human body. This study explored the DBP formation when only GO was present. Effects of Br〈sup〉−〈/sup〉 were also considered during the DBP formation. Both trihalomethanes (THMs) and haloacetic acids (HAAs) were formed during the chlorination and chloramination procedure, but the total concentration of THMs was at least three times higher than that of HAAs. Irradiation can significantly enhance the DBP formation via the formation of radicals. The wrinkled appearance and decomposition of aromatic ring may both be effective on the DBP formation via chlorination or bromination. The findings of this study advance knowledge on the DBP formation of GO in water treatment systems and provide insight on the toxic effects of the transformation products of GO.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Bo Liu, Jing Wu, Cheng Cheng, Jiukai Tang, Muhammad Farooq Saleem Khan, Jian Shen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract:〈/h5〉 〈div〉〈p〉Identifying the causes of water body pollution is critical because of the serious water contamination in developing countries. The textile industry is a major contributor to severe water pollution due to its high discharge of wastewater with high concentrations of organic and inorganic pollutants. In this study, fluorescence excitation emission matrix–parallel factor (EEM-PARAFAC) analysis was applied to characterize textile industry wastewater and trace its presence in water bodies. The EEM spectra of textile wastewater samples collected from 12 wastewater treatment plants (WWTPs) revealed two characteristic peaks: Peak T1 (tryptophan-like region) and Peak B (tyrosine-like region). Two protein-like components (C1 and C2) were identified in the textile wastewater by PARAFAC analysis. The components identified from different textile WWTPs were considered identical (similarity 〉0.95). C1 and C2 were not sensitive to changes in pH, ionic strength, or low humic acid concentration (TOC 〈 4 mg/L). Therefore, C1 combined with C2 was proposed as a source-specific indicator of textile wastewater, which was further demonstrated by conducting high-performance size exclusion chromatography analysis. These results suggested that EEM-PARAFAC analysis is a reliable means of identifying textile wastewater pollution in water bodies and may also enable the identification of other industrial wastewater.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320162-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Bo Chen, Sijiang Chen, Huinan Zhao, Yang Liu, Fengxia Long, Xuejun Pan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ascribing to their significant differences in physicochemical properties, it is extremely challenging to treat complex wastewater containing more than one class of pollutants via one-step treatment. Here, we focused on disposal of complex wastewater bearing organic dye and heavy metal by using adsorptive method. Thus, by combining the advantages of polyethyleneimine (PEI), β-cyclodextrin (β-CD) as well as Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 magnetic nanoparticles, a versatile β-CD and PEI bi-functionalized magnetic nanoadsorbent (Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-PEI/β-CD) with spatially separated sorption sites was successfully constructed for simultaneous capture of methyl orange (MO) and Pb(II) in complex wastewater. In this setting, β-CD cavities and positively charged N-containing groups of PEI were mainly responsible for removal of MO via host-guest inclusion and electrostatic attraction, respectively, and oxygen-bearing groups on the edge of β-CD as well as the free amino moieties in PEI acted as the active sites for Pb(II) uptake. In their individual mono-pollutant system, the adsorption processes can be better described via applying pseudo-second-order kinetic and Langmuir isotherm models. Interestingly, presence of MO in Pb(II)-MO binary system significantly promoted the uptake of Pb(II). But the coexisting Pb(II) had almost no effects on MO uptake. Such results demonstrated that both MO and Pb(II) could be simultaneously and synergistically removed by Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-PEI/β-CD through multiple mechanisms (such as electrostatic attraction, host-guest inclusion, chelating, etc.). Particularly, the excellent regeneration and stability make Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-PEI/β-CD an ideal integrative adsorbent for purification of actual wastewater contaminated by MO and Pb(II). Thus, this study provides some insights into designing a well-performed and easily recyclable adsorbent for simultaneous and synergetic capture of both organic and inorganic contaminants in complex wastewater.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉A versatile β-CD and PEI bi-functionalized magnetic nanoadsorbent with spatially separated sorption sites (denoted as Fe3O4-PEI/β-CD) was successfully constructed for simultaneous removal of methyl orange (MO) and Pb(II) from complex wastewater through multiple mechanisms (such as electrostatic attraction, host-guest inclusion, chelating, etc.).〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320198-fx1.jpg" width="444" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Xian Cao, Shuai Zhang, Hui Wang, Xianning Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In general, refractory organics were hardly used as co-substrate in bioelectrochemical system. This study established a coupled bioelectrochemical system composed of a biofilm electrode reactor and a microbial fuel cell for using the azo dye X-3B as part of co-substrate. The two units degraded the azo dye X-3B stepwise while using it as part of co-substrate. Our results indicated that the removal efficiency of X-3B increased 28.5% using the coupled system compared with a control system. Moreover, the addition of the co-substrate glucose, which was necessary for MFC electricity generation, was reduced on the premise of stable removal efficiency in the coupled system to prevent resource waste due to using X-3B as part of co-substrate. The intermediate products of X-3B degradation were further explored using gas chromatography–mass spectrometry and a X-3B degradation pathway was proposed at the same time. Microbial communities were analyzed, illustrating that the mechanism of X-3B degradation was dependent on bioelectrochemistry rather than on microbial degradation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Nikita Bakanov, Matthias V. Wieczorek, Ralf Schulz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding fate and transport of plant protection products (PPPs) that enter vegetated streams from agricultural fields is important for both exposure assessment and risk attenuation, yet limited knowledge is available. The present laboratory study investigated sorption processes governing mass transfer of three common PPPs between water and aquatic plant phases at flow-through exposure conditions (transient aqueous-phase PPP-peak of 4 h 25 min) using three temperature regimes. The exposure produced rapid sorption of PPPs to plants, followed by a gradual depuration from plants. Dynamic sorption kinetics depended on temperature, plant species, and physicochemical properties of the PPPs. Sorption to plants contributed to a 10% reduction of the water-phase peak concentrations of the PPPs. However, being reversible, the attenuation effect was limited to the residence time of the PPPs in the systems. Results of the present study highlight that effectivity of aquatic plants in the attenuation of PPP loads may vary greatly depending on hydrodynamic properties of aquatic systems.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Huihui Wang, Hui Ma, Min Zhang, Tingting Du, Rongjie Hao, Mengmeng Liu, Yao Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Disinfection byproducts (DBPs) can be formed from many different kinds of carbon- and nitrogen-based organic materials. This study investigated DBP formation in the presence of two types of polybrominated diphenyl ethers (PBDEs), 2,2′,4,4′-tetrabromodiphenyl ether (BDE 47) and 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE 209). The effects of PBDEs on the formation of DBPs upon the chlorination (or chloramination) of Suwannee River humic acid (SRHA) were also evaluated. Results indicated that the chlorination of BDE 47 and BDE 209 resulted in the formation of DBPs, with 1,1,1-trichloro-2-propanone (1,1,1-TCP) being the major DBP type formed. When PBDEs were present in the SRHA solution, a lower amount of CHCl〈sub〉3〈/sub〉 was formed, and more 1,1,1-TCP was produced. However, the effects of PBDEs on the formation of DBPs in the real surface water were insignificant because of the complicated water chemistry.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Jiena Yun, Chang Zhu, Qian Wang, Qiaoli Hu, Gang Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Sulfur dioxide (SO〈sub〉2〈/sub〉) ranks as a major air pollutant and is likely to generate acid rain. When molecular oxygen is the oxygen source, the regular surfaces of gibbsite (one of the most abundant mineral dusts) show no reactivity for SO〈sub〉2〈/sub〉 conversions to H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉, while the partially dehydrated (100) surface with coordination-unsaturated Al sites becomes catalytically effective. Because of the easy availability of molecular oxygen, results manifest that acid rain can form under all atmospheric conditions and may account for the high conversion ratio of atmospheric SO〈sub〉2〈/sub〉. The (100) and (001) surfaces show divergent catalytic effects, and hydrolysis is always the rate-limiting step. Path A (hydrolysis and then oxidation) is preferred for (100) surface, whereas a third path with obviously lower activation barriers is presented for (001) surface, which is non-existent for (100) surface. Atomic oxygen originating from the dissociation of molecular oxygen is catalytically active for (100) surface, while the active site of (001) surface fails to be recovered, suggesting that SO〈sub〉2〈/sub〉 conversions over gibbsite surfaces are facet-controlled. This work also offers an environmentally friendly route for production of H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 (one of the essential compounds in chemical industry), directly using molecular oxygen as the oxygen source.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320769-fx1.jpg" width="326" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Guanghui Wang, Wenzhe Fan, Qin Li, Nansheng Deng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, aspartic acid-β-cyclodextrin (ACD) was synthesized by the reaction of β-cyclodextrin with aspartic acid and epichlorohydrin, and graphene oxide-TiO〈sub〉2〈/sub〉 (GO-TiO〈sub〉2〈/sub〉) composite catalyst was prepared by a hydrothermal method. The complexation of ACD with New Coccine (NC) and Pb〈sup〉2+〈/sup〉 was characterized with FT-IR and XPS, respectively, the results show that ACD can simultaneously complex NC and Pb〈sup〉2+〈/sup〉. XRD analysis and SEM images of GO-TiO〈sub〉2〈/sub〉 show that TiO〈sub〉2〈/sub〉 platelets are well distributed on both sides of the graphene oxide sheets, and display a similar XRD pattern to the pure TiO〈sub〉2〈/sub〉 nanoparticles with the typical diffraction peak of anatase phase. The effects of ACD on the photocatalytic degradation of NC and photocatalytic reduction of Pb〈sup〉2+〈/sup〉 were investigated in the single pollution system, and the synergistic effects on the simultaneous photocatalytic NC degradation and Pb〈sup〉2+〈/sup〉 reduction in the presence of ACD were also evaluated. The results showed that the presence of ACD was favorable to the acceleration of photocatalytic oxidation of NC and photocatalytic reduction of Pb〈sup〉2+〈/sup〉 in the single pollution system, and the photocatalytic reaction rate constants of NC and Pb〈sup〉2+〈/sup〉 in the presence of ACD increased 58% and 42%, respectively. For the combined pollution system, the synergistic effects on the simultaneous conversion of NC and Pb〈sup〉2+〈/sup〉 in aqueous solutions were also further enhanced. ACD enhanced photocatalytic activity was attributed to the improvement of the electron transfer and mass transfer at the GO-TiO〈sub〉2〈/sub〉 interface.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Xinbo Wang, Hong Cheng, Peiying Hong, Xixiang Zhang, Zhiping Lai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Despite advanced materials and techniques to reduce the fouling issue of membranes, 10–30% of the cost of ultrafiltration (UF) processes have been spent on membrane cleaning. Particularly in water treatment, the traditional heavy metal-based method is challenged due to its environmental pollution risk and increasing public health awareness. Here, we report the synthesis of a metal-free contact-active antifouling and antimicrobial membrane by covalently functionalizing a commercial polyacrylonitrile (PAN) UF membrane with 2,4-diamino-1,3,5-triazine (DAT) via a one-step catalyst-free hydrothermal [4 + 2] cyclization of dicyandiamide reaction. The proposed mechanism of the antimicrobial activity of the DAT-functionalized membrane is through strong attraction between the DAT groups and the microbial membrane protein via strong hydrogen bonding, leading to microbial membrane disruption and thus microbe death. A high water flux and good reusability of the membrane against protein in a UF experiment were achieved. The low cost, easy availability of the compounds, as well as the facile reaction offer a high potential of the membrane for real applications in ultrafiltration.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Jalil Jaafari, Kamyar Yaghmaeian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, the interaction of the initial metal concentration, time of reaction and 〈em〉Chlorella coloniales〈/em〉 algae dose were taken for the biosorption of Cr, Cd, Co, Fe and As from aqueous solutions using the Box–Behnken design. The regression equation coefficients were calculated and the data confirmed the validity of second-order polynomial equation for the removal of Cr, Cd, Co, Fe and As with 〈em〉Chlorella coloniales〈/em〉 algae. Analysis of variance (ANOVA) showed a high coefficient of determination value (R〈sup〉2〈/sup〉) for Cr, Cd, Co, Fe, and As, being respectively 0.998, 0.998, 0.995, 0.998 and 0.994. Heavy metal biosorption increased with the increase in time of reaction from 30 h to 100 h then smoothly steadily decreased. The biosorption capacity of 〈em〉Chlorella coloniales〈/em〉 increased when initial Cd concentration was increased from 5 to 12 mg/L, and then no change was seen with further increasing in initial Cd concentration. At low concentrations of heavy metal, 〈em〉Chlorella coloniales〈/em〉 showed its effectiveness for Cr, Co, Fe and As bioaccumulation, but at high concentrations of heavy metal bioaccumulation efficiency decreased Under optimal value of process parameters, maximum efficiencies for the removal of Cr, Cd, Co, Fe, and As were 97.8, 97.05, 95.15, 98.6 and 96.5% respectively. The results of the present study suggest that use of 〈em〉C. Coloniales〈/em〉 algae can be a good alternative to the current expensive methods of removing heavy metals from aqueous solution.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Khalid Rehman Hakeem, Hesham F. Alharby, Reiazul Rehman〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of lead (Pb)-induced oxidative stress was investigated in 〈em〉Fagopyrum kashmirianum〈/em〉. The seedlings absorbed the Pb readily by showing time (15 and 30 days) and concentration (0, 100, 200 and 300 μM) dependent effects. Pb caused reduction in both root and shoot lengths but its accumulation was more in roots (22.32 mg g〈sup〉−1〈/sup〉 DW) than shoots (8.86 mg g〈sup〉−1〈/sup〉 DW) at the highest concentration (300 μM) resulting in translocation factor (TF) 〈 1 at all concentrations. Thus the uptake and translocation of Pb between roots and shoots showed a positive correlation indicating the plant as root accumulator. Amongst the photosynthetic pigments, chlorophyll content showed a decline while the carotenoid and anthocyanin levels were elevated. The fresh mass and biomass showed a non-significant decrease at both the sampling times. The osmolyte and antioxidative enzymes (SOD, CAT, APX. POD, GR and GST) were positively correlated with Pb treatments except proline and CAT, which showed decline in 30-day-old plants. The alleviation of Pb-stress is an indication for existence of strong detoxification mechanism in 〈em〉F. kashmirianum, which〈/em〉 suggest that it could be cultivated in Pb-contaminated soils.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Celestina E. Sobral – Souza, Ana R.P. Silva, Nadghia F. Leite, Janaina E. Rocha, Amanda K. Sousa, José G.M. Costa, Irwin R.A. Menezes, Francisco A.B. Cunha, Larissa A. Rolim, Henrique D.M. Coutinho〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study had as its objective to verify the 〈em〉Psidium guajava〈/em〉 var. Pomifera L. chelating, antioxidant and cytoprotective effects against mercury and aluminum. The ethanolic extract, tannic and flavonoid fractions were subjected to LC-MS analysis. The Ferric Reducing Antioxidant Power (FRAP) and ferric ion reduction demonstrated a present antioxidant activity. The fungicidal and bactericidal activity of these metals were established. After determining the sub-allelopathic doses, germination tests using 〈em〉Lactuca sativa〈/em〉 were performed. Quercetin and its derivatives were the main compounds identified in the extract and the fractions. Mercury chloride significantly reduced the bactericidal effect of the flavonoid fraction (p 〈 0.001). None of the fractions were cytoprotective against mercury or aluminum in the fungal model assays. Using a sub-allelopathic concentration (64 μg/mL), the ethanolic extract, flavonoid and tannic fractions were found to be cytoprotective against aluminum for radicles, however only the tannic fraction was cytoprotective for caulicles. These data suggest that natural 〈em〉P. guajava〈/em〉 products are promising cytoprotective compound sources. This activity may be related to the antioxidant effect of secondary metabolites, mainly flavonoids. Our results point to a potential for environmental intervention product and technique development aimed at mitigating contamination by toxic metals such as mercury and aluminum.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Jie Luo, Xinli Xing, Shihua Qi, Jian Wu, X.W. Sophie Gu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hyperaccumulators can mobilize all metals in soil through secreting exudates to form soluble compounds but only hyperaccumulate part of them. Metals that cannot be accumulated are defined as non-hyperaccumulated metals and can increase the leaching risk in phytoremediation. Cd and Zn hyperaccumulator 〈em〉Noccaea caerulescens〈/em〉 (formerly 〈em〉Thlaspi caerulescens〈/em〉) was utilized to remediate multi-metal polluted soil in the present study, and the leaching risk of non-hyperaccumulated metals including Cu and Pb was investigated during the phytoremediation process. Comparing with 〈em〉Thlaspi arvense〈/em〉, a non-hyperaccumulator, 〈em〉N. caerulescens〈/em〉 significantly decreased the concentrations of Cd and Zn in leachate gathered from precipitation simulation experiments without electric field, but meanwhile dramatically increased the concentrations of Cu and Pb in soil solution. Electric field with low (2 V) and moderate (4 V) voltages increased the biomass yield and metal uptake capacity of 〈em〉N. caerulescens〈/em〉 simultaneously and therefore further reduced the concentrations of Cd and Zn in the leachate. Although the volume of leachate decreased significantly in pots with electric field, the leaching risk of Pb and Cu was deteriorated. Thus, decontaminating multi-metal polluted soil with electric field and hyperaccumulator should be conducted with caution due to potential secondary environmental risk caused by activated non-hyperaccumulated metals.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320320-egi10NH7JS1ZHN.jpg" width="286" alt="Image" title="Image"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Haitao Shen, Weiwei Li, Stephen E. Graham, James M. Starr〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ingestion of soils and house dusts is an important pathway for children's exposure to sorbed organic pollutants such as polychlorinated biphenyls (PCBs). To reduce the uncertainty of the exposure estimates, it is important to understand the extent to which chemicals desorb and become bioaccessible following ingestion. In this study we use a three compartment in vitro digestive system to model the role of soil and house dust physicochemical properties on the post ingestion bioaccessibility of PCBs. Matched pairs (n = 37) of soil and dust were characterized for percent carbon and nitrogen, pH, moisture content, and particle size distribution. They were then fortified with a mixture of 18 PCBs and processed through the assay. The percent bioaccessibility of each PCB was calculated, then modeled using individual PCB log K〈sub〉ow〈/sub〉 values and the soil and dust properties. The bioaccessibility of the PCBs in soil (x̄ = 65 ± 16%) was greater (p 〈 0.001) than that of the PCBs in house dust (x̄ = 36 ± 14%). In the soil model, carbon was the sole statistically significant predictive (p ≤ 0.05) variable, while in house dust, both carbon and clay content were statistically significant (p ≤ 0.05) predictors.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320666-fx1.jpg" width="355" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Xue Wu, Zheng Bo Zhu, Jia Hui Chen, Yi Fan Huang, Zi Li Liu, Jian Wen Zou, Ya Hua Chen, Na Na Su, Jin Cui〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrogen-rich water (HRW) has been widely used in research on plant resistance to Cd. However, the underlying molecular mechanism of HRW in ameliorating cadmium stress in vegetables is largely unknown. In this study, the RNA-sequencing analyses were used to characterize the role of HRW in the alleviation of Cd toxicity in Chinese cabbage seedlings. Based on the obtained results, two genes encoding metal ionic transporters, 〈em〉BcIRT1〈/em〉 and 〈em〉BcZIP2〈/em〉 were ultimately selected out. Then, a systematic validation of the metal ion transport function of these two ZIP-encoding genes of pak choi were performed via a yeast transformation system. The results showed that 〈em〉BcIRT1〈/em〉 and 〈em〉BcZIP2〈/em〉 increased the sensitivity of different yeast mutant strains to relative metal ionic stresses and facilitated the accumulation of metal ions (Cd〈sup〉2+〈/sup〉, Mn〈sup〉2+〈/sup〉, Zn〈sup〉2+〈/sup〉, and Fe〈sup〉2+〈/sup〉) in yeast; thus, it suggests that 〈em〉BcIRT1〈/em〉 and 〈em〉BcZIP2〈/em〉 probably have the ability to transport Cd〈sup〉2+〈/sup〉, Mn〈sup〉2+〈/sup〉, Zn〈sup〉2+〈/sup〉 and Fe〈sup〉2+〈/sup〉 in pak choi. The time-course and concentration-dependent expression profiles of 〈em〉BcIRT1〈/em〉 and 〈em〉BcZIP2〈/em〉 showed that as time with HRW increased, the effectiveness of the repression on the expression of 〈em〉BcIRT1〈/em〉 and 〈em〉BcZIP2〈/em〉 increased, and as the seedlings were exposed to increased Cd concentrations, the inhibition of 〈em〉BcIRT1〈/em〉 and 〈em〉BcZIP2〈/em〉 by HRW was also increased. Over all, these findings provide new insights into the genome-wide transcriptome profiles in pak choi and show that HRW reduced Cd uptake probably through inhibiting the expression of transporters related to Cd absorption, 〈em〉BcIRT1〈/em〉 and 〈em〉BcZIP2〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Peter Butcherine, Kirsten Benkendorff, Brendan Kelaher, Bronwyn J. Barkla〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Widespread agricultural use of systemic neonicotinoid insecticides has resulted in the unintended contamination of aquatic environments. Water quality surveys regularly detect neonicotinoids in rivers and waterways at concentrations that could impact aquaculture stock. The toxicity of neonicotinoids to non-target aquatic insect and crustacean species has been recognised, however, there is a paucity of information on their effect on commercial shrimp aquaculture. Here, we show that commercially produced shrimp are likely to be exposed to dietary, sediment and waterborne sources of neonicotinoids; increasing the risks of disease and accidental human consumption. This review examines indicators of sublethal neonicotinoid exposure in non-target species and analyses their potential usefulness for ecotoxicology assessment in shrimp. The identification of rapid, reliable responses to neonicotinoid exposure in shrimp will result in better decision making in aquaculture management.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Maqusood Ahamed, Mohd Javed Akhtar, M.A. Majeed Khan, Salman A. Alrokayan, Hisham A. Alhadlaq〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bismuth oxide nanoparticles (Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs) have shown great potential for several applications including cosmetics and biomedicine. However, there is paucity of research on toxicity of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs. In this study, we first examined dose-dependent cytotoxicity and apoptosis response of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs in human breast cancer (MCF-7) cells. We further explored the potential mechanisms of cytotoxicity of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs through oxidative stress. Physicochemical study demonstrated that Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs have crystalline structure and spherical shape with mean size of 97 nm. Toxicity studies have shown that Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs reduce cell viability and induce membrane damage dose-dependently in the concentration range of 50–300 μg/ml. Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs also disturbed cell cycle of MCF-7 cells. Oxidative stress response of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs was evident by generation of reactive oxygen species (ROS), higher lipid peroxidation, reduction of glutathione (GSH) and low superoxide dismutase (SOD) enzyme activity. Interestingly, supplementation of external antioxidant N-acetyl-cysteine almost negated the effect of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs induced oxidative stress and cell death. We also found that exposure of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs induced apoptotic response in MCF-7 cells suggested by impaired regulation of Bcl-2, Bax and caspase-3 genes. Altogether, we found that Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs induced cytotoxicity in MCF-7 cells through modulating the redox homeostasis 〈em〉via〈/em〉 Bax/Bcl-2 pathway. This study warranted further research to delineate the underlying mechanism of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs induced toxicity at 〈em〉in vivo〈/em〉 level.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320897-fx1.jpg" width="492" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Xingdong Wang, Qiaoqiao Chi, Xuejiao Liu, Yin Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel approach was used to prepare sewage sludge (SS)-derived biochar via coupling of hydrothermal pretreatment with pyrolysis (HTP) process at 300–700 °C. The influence of the pyrolysis temperature on the characteristics and environmental risk of heavy metals (HMs) in biochar derived from SS were investigated. The HTP process at higher pyrolysis temperature (≥500 °C) resulting in a higher quality of SS-derived biochar and in HMs of lower toxicity and environmental risk, compared with direct SS pyrolysis. Surface characterization and micromorphology analysis indicate that the N〈sub〉2〈/sub〉 adsorption capacity and BET surface area in biochar (SRC〈sub〉220〈/sub〉-500) obtained from hydrothermally treated SS at 220 °C (SR〈sub〉220〈/sub〉) pyrolysis at 500 °C, significantly increased the BET surface area and achieved its maximum value (47.04 m〈sup〉2〈/sup〉/g). Moreover, the HTP process can promote the HMs in SS be transformed from bioavailable fractions to more stable fractions. This increases with the pyrolysis temperature, resulting in a remarkable reduction in the potential environmental risk of HMs from the biochar obtained from the HTP process.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320605-fx1.jpg" width="340" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Yan Wang, Qiaonan Zhang, Yuwei Zhang, Hongxia Zhao, Feng Tan, Xiaowei Wu, Jingwen Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Concentrations and temporal variations of priority polycyclic aromatic hydrocarbons (PAHs) in the air from a suburban area of Dalian, China were investigated for a 1-year period to assess their sources and potential correlations with six criteria air pollutants and meteorological parameters. The total concentrations of PAHs were in the range of 4.32–112.2 ng/m〈sup〉3〈/sup〉 (Mean = 52.37 ± 23.99 ng/m〈sup〉3〈/sup〉). Seasonality was discovered with the PAHs following an order of winter 〉 spring 〉 summer 〉 autumn. The impacts of meteorological parameters on PAH levels were season-dependent. High temperature may increase the air concentrations of 4-ring PAHs during the non-heating period, whereas high relative humidity may raise the concentrations of 3- and 4-ring PAHs during the heating period. Correlations of PAHs with criteria air pollutants, such as SO〈sub〉2〈/sub〉, NO〈sub〉2〈/sub〉, and O〈sub〉3〈/sub〉, indicated that both fossil fuel combustion and photochemical oxidation influenced the air concentrations of PAHs. According to the source apportionment by diagnostic ratios and PMF model, coal combustion and traffic emission were estimated to be the main sources of PAHs in Dalian, followed by petroleum release and biomass burning. It was worth noting that the contribution of coal combustion to the PAH burdens increased from 26% to 45% due to the emission from domestic heating in winter. This extra emission needs a continuous concern in the future.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320551-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Min Liu, Shenglan Jia, Ting Dong, Yuan Han, Jingchuan Xue, Elvy Riani Wanjaya, Mingliang Fang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bisphenol A diglycidy ether (BADGE) and its derivatives are epoxy resins and widely used as emerging plasticizers in food packages and material coating. Though known as endocrine disruptors, little information is available on their occurrence, exposure routes and toxicity. Besides, the analysis of BADGE and its derivatives has always been a challenge due to their reactive chemical properties and the background contamination. Therefore, we firstly developed a novel water-free method to analyze BADGE and its derivatives in dust samples together with other two typical plasticizers bisphenol A (BPA) and bisphenol S (BPS). In order to investigate the levels in paired dust and urine samples, 33 paired samples were collected from Singapore. In both dust and urine samples, the predominant compounds were BPA, BADGE-2H〈sub〉2〈/sub〉O and BPS. A significantly positive correlation of BPA levels in paired dust and urine samples was observed in this small-scale study. To tentatively explore the human health effect from exposure to these bisphenol plasticizers, we assessed the correlation between the urinary concentrations of these compounds and oxo-2’-deoxyguanosine (8-OHdG), an oxidative stress biomarker. The result showed that 8-OHdG levels in urine samples was positively correlated with urinary BPA level and body mass index (BMI), suggesting that elevated oxidative stress might be associated with BPA exposure and obesity. In the future, a larger scale study is warranted due to the limited sample size in this study.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518319453-fx1.jpg" width="300" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Tao Cui, Chenyang Shen, Anlin Xu, Weiqing Han, Jiansheng Li, Xiuyun Sun, Jinyou Shen, Lianjun Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, a novel coupled-oxidation tubular reactor (COTR)/non-thermal dielectric barrier discharge (NTP-DBD) catalytic plasma in a synergistic electro-catalysis system was investigated for odorous mercaptans decomposition. In order to enhance the degradation efficiency of electro-oxidation, a novel enhanced Ti/PbO〈sub〉2〈/sub〉 electro-catalytic tubular reactor prepared by using flow dynamic electrodeposition was designed and applied as pretreatment process for CH〈sub〉3〈/sub〉SNa wastewater. The results indicated that the optimal condition was 7 mA cm〈sup〉−2〈/sup〉 of current density, 10 g L〈sup〉−1〈/sup〉 of initial concentration of CH〈sub〉3〈/sub〉SNa, 9.0 of pH and 5.0 g L〈sup〉−1〈/sup〉 of electrolyte concentration. Addition of Fe〈sup〉2+〈/sup〉 and H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 and mechanism of COTR system were first put forward. The target species CH〈sub〉3〈/sub〉SNa were removed over 90% by this process. In order to treat the CH〈sub〉3〈/sub〉SH effusion which was co-produced with CH〈sub〉3〈/sub〉SNa aqueous solution, the technology of NTP-DBD catalytic plasma reactor followed by a chemical absorption has been developed. MSH could be removed over 95% under the condition of 2 s of residence time, 15 kV of output voltage with oxygen concentration of 9%. Moreover, the synthetic Ni-doped AC catalyst had the best performance under 0.7 mmol g〈sup〉−1〈/sup〉 of nickel loading. The conclusion was the energetic electrons generated in the DBD reactor played a key role on the removal of MSH, and the major decomposition products of MSH were detected as CH〈sub〉3〈/sub〉SSCH〈sub〉3〈/sub〉, SO〈sub〉2〈/sub〉 and NO〈sub〉2〈/sub〉. Moreover, the gaseous products in the plasma exhaust could be absorbed and fixed by the subsequent aqueous NaOH solution.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320411-fx1.jpg" width="359" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Changlong Wei, Xin Song, Qing Wang, Yun Liu, Na Lin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉6:2 chlorinated polyfluorinated ether sulfonate (trade name F-53B), a perfluorooctane sulfonate alternative used as a mist suppressant in the chromium plating industry, is environmentally persistent and bioaccumulative. In this study, the kinetic and equilibrium data of F-53B sorption onto soils were obtained to investigate the relationship between sorption parameters and soil attributes. The effects of potential coexisting Cu(II), anionic Cr(VI) and sulfate on F-53B sorption by soils were explored. This is the first report of the effects of F-53B sorption behavior on soils with coexisting contaminants of Cu(II) and Cr(VI). The results showed that sorption kinetics of F-53B on soils could be well-fitted by the pseudo-second-order model. The maximum F-53B sorption capacity ranged from 22.71 to 92.36 mg/kg on six different soils, and the correlation analysis indicated a positive relationship between the maximum sorption capacity and the soil organic content, Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, and Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉. The desorption percentages of F-53B in this study, defined as the proportion of sorbed F-53B on soils that was recovered upon desorption, were lower than 8.2%. Moreover, F-53B sorption capacities generally decreased in the presence of Cu(II), Cr(VI), and sulfate, indicating that these ions can facilitate the F-53B mobility in the subsurface. Taken together, these findings suggest that electrostatic interaction, hydrophobic interaction, ligand exchange, and surface complexation contributed to the F-53B sorption on soils.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 147〈/p〉 〈p〉Author(s): Nidhi, K.A. Subramanian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present experimental investigation deals with the study of the effect of oxygen enriched intake air on performance, emission and combustion characteristics of a methanol (M100) fuelled spark ignition engine. The oxygen in the intake air of the engine fuelled with methanol was enriched from 23% (by mass) with base oxygen to 26.5%, 38.7% and 60.4%. The brake thermal efficiency increased drastically with methanol with 38.7% and 60.4% enriched air by 9.9% and 20.5% respectively. The peak pressure and cumulative heat release with the highest enriched air (60.4%) are higher about 2 and 1.27 times than base oxygen percentage (23% by mass). The ignition delay and combustion duration decreased by 35.24% and 57.8% respectively. Carbon monoxide (CO) and hydrocarbon (HC) emissions with the highest enriched air decreased substantially by 48.59% and 30.9%. However, nitrogen oxides (NO〈sub〉x〈/sub〉) emission increased drastically by 112.2% with 38.7% of oxygen but it decreased by 31.5% with 60.4% oxygen enriched air which is lower than base oxygen. A notable conclusion emerged from this study is that a methanol fuelled engine with the oxygen enriched air (60.4%) could emit very lower emissions (CO, HC, NO〈sub〉x〈/sub〉) along with improved thermal efficiency compared to base oxygen (23% by mass).〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 25 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 147〈/p〉 〈p〉Author(s): Manuel Colera, Ángel Soria, Javier Ballester〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work we present a numerical scheme for the steady-state thermodynamic analysis of gas turbine engines. As usual in the literature, it is based on modelling the gas turbine as a set of independent components connected through nodes, thus giving the user great flexibility to modify the gas turbine’s model and to define and include new components. Additionally, the proposed method provides the same flexibility for the inclusion of new gas properties calculators and nonlinear equations solvers. The simulator also allows identifying the characteristic parameters of the different components of the gas turbine –such as the compressor’s nominal pressure ratio and efficiency– from a batch of operation data. The latter task is accomplished by means of a systematic and computationally economic procedure which allows that the parameters identification be performed component-by-component and does not require any full gas turbine simulations. The scheme has been formulated so that it exploits the full capabilities of today’s computers and mathematical techniques –such as sparse matrix solvers and quasi-Newton methods for sparse jacobians– but, at the same time, remains simple enough to be self-implemented by the interested researchers with the aid of general-purpose mathematical computing software such as Matlab. The simulator has been applied to predict the performance of a real gas turbine, obtaining excellent results.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): N. Cartiglia, R. Arcidiacono, M. Ferrero, M. Mandurrino, H.-F.W. Sadrozinski, V. Sola, A. Staiano, A. Seiden〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The combination of precision space and time information in particle tracking, the so called 4D tracking, is being considered in the upgrade of the ATLAS, CMS and LHCb experiments at the High-Luminosity LHC, set to start data taking in 2024-25. Regardless of the type of solution chosen, space–time tracking brings benefits to the performance of the detectors by reducing the background and sharpening the resolution; it improves tracking performances and simplifies tracks combinatorics. Space–time tracking also allows investigating new physics channels, for example it opens up the possibilities of new searches in long-living particles by measuring accurately the time of flight between the production and the decay vertexes. The foreseen applications of 4D tracking in experiments with very high acquisition rates, for example at HL-LHC, add one more dimension to the problem, increasing dramatically the complexity of the read-out system and that of the whole detector design: we call 5D tracking the application of 4D tracking in high rate environments.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 913〈/p〉 〈p〉Author(s): George Kitis, Vasilis Pagonis〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Experimental Thermoluminescence (TL) glow curves for most dosimetric materials are composites, consisting of weakly or strongly overlapping peaks. The ability to discriminate between two overlapping peaks defines the resolution of a TL glow curve. Although the concept of resolution has been defined and used widely in many areas of science, there have been no previous attempts to define and study the resolution of overlapping TL peaks. In this work the resolution parameter R is defined in terms of the geometrical characteristics of TL peaks. A large number of TL glow curves consisting of two peaks were numerically evaluated for various degrees of overlapping between them. These numerically generated glow curves were analyzed by a computerized glow curve deconvolution analysis, in order to determine the reliability of the deconvolution results as a function of the resolution parameter R.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): S. Zhao, G. Lioliou, S. Butera, M.D.C. Whitaker, A.M. Barnett〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A Commercial-Off-The-Shelf (COTS) 4H-SiC p-n photodiode (sold as a UV detector) was investigated as detector of electrons (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si34.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉β〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 particles) over the temperature range 100 °C to 20 °C. The photodiode had an active area of 0.06 mm〈sup〉2〈/sup〉. The currents of the photodiode were measured in dark condition and under the illumination of a 〈sup〉63〈/sup〉Ni radioisotope 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si34.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉β〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 particle source (endpoint energy = 66 keV). The photodiode was then coupled to a custom-made low-noise charge-sensitive preamplifier to make a direct detection particle counting electron spectrometer. 〈sup〉63〈/sup〉Ni 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si34.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉β〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 particle spectra were accumulated with the spectrometer operating at temperatures up to 100 °C. The quantum efficiency of the photodiode as well as the spectrum expected to be detected were calculated via Monte Carlo simulations produced using the CASINO computer program. Comparisons between the simulated and detected 〈sup〉63〈/sup〉Ni 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si34.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉β〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 particle spectra are presented. The work was motivated by efforts to apply COTS technologies to develop low-cost space science instrumentation; a low-cost electron spectrometer of this type could be included on a university-led CubeSat mission for space plasma physics and magnetosphere experiments.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): M. Sharma, J. Nattress, I. Jovanovic〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Design of deuterium–tritium (DT) neutron generator facilities requires a careful assessment of radiation shielding. In the models of such facilities an isotropic distribution of neutron flux produced by the neutron generator is usually assumed. However, prior studies have shown that neutron flux surrounding the neutron generator can be anisotropic. This anisotropy results mostly from the design of the generator tube, as well as the angular dependence of DT fusion reaction cross section. In this work, the angular neutron flux was measured for a standard commercially available DT generator (Thermo Fisher Scientific, Model P211) using an organic scintillator and a significant degree of anisotropy was confirmed to exist. The experimentally determined flux was then used in Monte Carlo simulations to examine the impact of anisotropy on the effectiveness of radiation shielding. Although the shielding effectiveness is not considerably affected by the anisotropy, the dose rates in air around the unshielded generator can be significantly different from those predicted when an assumption of isotropic flux is made. These considerations need to be included in modeling of the dose rate around the generator in neutron generator facilities that employ typical neutron generators, which exhibit some degree of anisotropy in neutron flux.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): David Longuevergne〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The different processes at the origin of the dependence of the surface resistance with the RF magnetic field are still not fully understood. Several models have emerged since many years to explain the drop of the quality factor 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si96.gif"〉〈msub〉〈mrow〉〈mi〉Q〈/mi〉〈/mrow〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈/msub〉〈/math〉 (commonly called Q-drop) of a superconducting cavity versus the accelerating gradient. Experimental data are commonly fitted by applying a coarse approximation to convert the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si96.gif"〉〈msub〉〈mrow〉〈mi〉Q〈/mi〉〈/mrow〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈/msub〉〈/math〉 (a global property) into a surface resistance (local property). Extracting accurately the surface resistance from experimental data requires to take into account the RF field distribution over the accelerating structure contrary to what is commonly done in the community. Assuming a field dependent surface resistance does not allow anymore to use the well-known formula 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈msub〉〈mrow〉〈mi〉Q〈/mi〉〈/mrow〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈/msub〉〈mo〉=〈/mo〉〈mi〉G〈/mi〉〈mo〉∕〈/mo〉〈mi〉R〈/mi〉〈/math〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉s〈/mi〉〈/mrow〉〈/msub〉〈/math〉. This paper gives a procedure to perform an accurate conversion of the quality factor measured during a cavity test into a surface resistance to avoid any error in the evaluation of fitting parameters due to the geometry.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): S. Roy, S. Rudra, S. Shaw, S. Chatterjee, S. Chakraborty, R.P. Adak, S. Biswas, S. Das, S.K. Ghosh, S.K. Prasad, S. Raha〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Study of the stability of gain and energy resolution for a triple GEM detector has been performed under continuous radiation of X-ray with high rate, using premixed gas of Argon and CO〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/math〉 in 70/30 ratio and conventional NIM electronics. A strong 〈sup〉55〈/sup〉Fe X-ray source is used for this study. The novelty of this study is that for the stability test same source is used to irradiate the GEM chamber and to monitor the spectrum. The radiation is not collimated to a point but exposed to a larger area. Effect of temperature and pressure on these parameters are also studied. The detail method of measurement and the first test results are presented.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): T. Washimi, M. Kimura, M. Tanaka, K. Yorita〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A two-phase argon detector has high discrimination power between electron recoil and nuclear recoil events based on the pulse shape discrimination and the ionization/scintillation ratio (S2/S1). This character is very suitable for the dark matter search to establish the low background experiment. However, the basic properties of S2/S1 of argon are not well known, as compared with xenon. We report the evaluation of S2/S1 properties with a two-phase detector at drift-fields of 0.2–3.0 kV/cm. Finally, the discrimination power against electron recoil background of S2/S1 is discussed.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): A. Natochii, L. Burmistrov, F. Addesa, O. Bezshyyko, D. Breton, V. Chaumat, G. Cavoto, S. Dubos, Y. Gavrikov, F. Iacoangeli, J. Maalmi Di Bello, S. Montesano, V. Puill, R. Rossi, W. Scandale, A. Stocchi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A method to characterise the quality of a fused silica surface using a 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈mi〉β〈/mi〉〈/math〉-source is presented. Two fused silica bars (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈mn〉5〈/mn〉〈mo〉×〈/mo〉〈mn〉10〈/mn〉〈mo〉×〈/mo〉〈mn〉400〈/mn〉〈mspace width="1em"〉〈/mspace〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉mm〈/mi〉〈/mrow〉〈mrow〉〈mn〉3〈/mn〉〈/mrow〉〈/msup〉〈/math〉) were fabricated for the Cherenkov detector for proton Flux Measurement installed at vacuum chamber of the Super Proton Synchrotron at CERN. The resolution of such device is defined by the collection efficiency of the Cherenkov light, which is produced by relativistic charged particles in the fused silica. Thus, the surface quality of the radiator should be as good as possible to avoid light losses. The method is based on the scanning of the radiator surface with a 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉90〈/mn〉〈/mrow〉〈/msup〉〈mi〉S〈/mi〉〈mi〉r〈/mi〉〈/math〉 radioactive source and measurements of the Cherenkov light rate, detected by a PMT attached to the quartz bars. The data have been compared with a Monte-Carlo simulation, providing an estimation of the radiator’s probability of the total internal reflection and inefficient area at the edges of the bars.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): M. Usami, G. Boca, P.W. Cattaneo, M. De Gerone, F. Gatti, M. Nakao, M. Nishimura, W. Ootani, M. Rossella, Y. Uchiyama〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We studied the impact of radiation damage on scintillation counters read out by six SiPMs connected in series focusing on their time resolution. Six SiPMs from AdvanSiD were irradiated step by step with a 37 MBq 〈sup〉90〈/sup〉Sr source. At the integrated dose expected at the end of the MEG II experiment, the time resolution at 30 °C was measured to be worse by 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si29.gif"〉〈mo〉∼〈/mo〉〈/math〉29%. However, the deterioration is found to be reduced to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si29.gif"〉〈mo〉∼〈/mo〉〈/math〉6% at 10 °C since thermal dark noise is suppressed. We also tested the effect of connecting in series differently damaged SiPMs. We observed a position dependence of the time center in a counter, which worsened the time resolution.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Haeryong Yang, Gyujin Kim, Heung-Sik Kang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The hard X-ray free electron laser at the Pohang Accelerator Laboratory (PAL-XFEL) in the Republic of Korea achieved a saturation of free electron laser (FEL) beam at 14.5 keV with an unprecedented intensity of 2.8E+11 photons per pulse. Successfully maintaining a very small emittance electron beam along the 700-m long linac, maximizing the spectral overlap of undulator radiation along the undulator line by the undulator radiation spectrum analysis, and optimal matching between the electron beam and photon beam through the 100-m long undulator line have allowed saturation and reliable operation of a 14.5 keV FEL beam.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): F. Abudinen, K. Ackermann, P. Ahlburg, M. Albalawi, O. Alonso, L. Andricek, R. Ayad, V. Babu, Y. Bai, T. Bilka, R. Blanco, M. Boronat, A. Bozek, C. Camien, A. Caldwell, V. Chekelian, B. Deschamps, A. Dieguez, J. Dingfelder, Z. Doležal〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Belle II experiment will run with a reduced beam asymmetry and a factor of 40 higher instantaneous luminosity compared to the Belle experiment. To cope with this and to be able to perform high precision vertex measurements for charge conjugation parity violating processes, a pixel detector based on DEPFET technology will be installed in the center of Belle II. Its basic properties and the DAQ chain are presented in this article.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Zdzisław Dębicki, Karol Jędrzejczak, Jacek Karczmarczyk, Marcin Kasztelan, Ryszard Lewandowski, Jerzy Orzechowski, Jacek Szabelski, Maria Szeptycka, Przemysław Tokarski〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉We performed measurements of thermal and non-thermal neutron flux in underground laboratories in Gran Sasso, Italy and in Slanic Prahova, Romania. The measurements were made with a set of helium counters: bare for thermal neutrons and covered by blocks of moderator for higher energy neutrons. We found that thermal neutron flux in Slanic is four times smaller than in Gran Sasso, probably due to lack of alpha-radioactive sources in the surrounding rocks. In contrast, the flux of higher energy neutrons in Slanic proved to be 1.4 times higher than in Gran Sasso, which can be explained by higher cosmic muon flux in Slanic.〈/p〉 〈p〉Our result for thermal neutron flux is lower than results of most of the previous measurements carried out in LNGS laboratory but thanks to a different method of analysis the reliability of our results is very high. The result for higher energy neutrons agrees with average energy spectrum resulting from previous measurements.〈/p〉 〈p〉Our measurements in Slanic were the first ones ever performed in this laboratory, and can be used as a reference by future experiments.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Graeme Turkington, Kelum A.A. Gamage, James Graham〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Strontium-90 is one of the primary beta-emitting radionuclides found at nuclear decommissioning sites. Monitoring its activity in the environment is of utmost importance given its radiotoxicity. Current procedures for the beta detection of strontium-90 are time consuming, produce secondary waste and expensive. There is a demand for real-time in situ radiostrontium monitoring in groundwater at nuclear decommissioning sites. This paper presents a review of existing techniques for strontium-90 monitoring and examines a novel approach through direct beta detection with a gallium arsenide photodiode based detector. A proof of concept detector was modelled in the physics simulation software, Geant4, and evaluated as candidate for in situ detection of beta emitting radionuclides. The simulation results indicate that the detector is physically capable of counting 89.86% of incident 0.546 MeV electrons from a 1 mm range in water. This validation will provide the basis for further development of an in situ beta detector.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): A. Di Mauro, on behalf of the ALICE Collaboration〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉ALICE, the CERN LHC experiment devoted to the study of the QGP (Quark-Gluon Plasma) properties, will undergo a comprehensive upgrade during the second long shutdown of the LHC (in 2019-2020) to enhance the capability for high precision measurements of rare processes at low transverse momenta (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msub〉〈mrow〉〈mi〉p〈/mi〉〈/mrow〉〈mrow〉〈mi〉T〈/mi〉〈/mrow〉〈/msub〉〈/math〉). One of the key elements of the upgrade strategy is the novel, high-resolution, ultra-light Inner Tracking System (ITS) consisting of seven concentric layers of Monolithic Active Pixel Sensors (MAPS) covering a total active area of 10 m〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si42.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 segmented in 12.5 Gpixels. This paper presents an overview of the detector components, the most relevant characterisation results and the status of the detector construction.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): N. Karpushkin, D. Finogeev, M. Golubeva, F. Guber, A. Ivashkin, A. Izvestnyy, V. Ladygin, S. Morozov, A. Kugler, V. Mikhaylov, A. Senger〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) is aimed to explore the QCD phase diagram in the region of high baryon densities. The Projectile Spectator Detector (PSD) is the forward hadron calorimeter that will be used in the CBM to measure the event centrality as well as the reaction plane orientation in heavy-ion collisions in the beam energy range of 2–11 〈em〉A〈/em〉GeV with beam interaction rates up to 10 MHz. The supermodule consisting of 9 modules has been assembled to explore the performance of the PSD. Its response has been studied with proton beams in the momentum range 2–10 GeV/c at the CERN Proton Synchrotron (PS) T9 and T10 beam lines. For the first time, the energy resolution and the linearity of the response have been measured at such low energies. The PSD operation under radiation conditions at the CBM, as well as the results of one PSD module measurements with irradiated photodetectors are discussed.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Jan Grzegorz Hajnrych, Philippe Filliatre, Benoît Geslot〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A comparison between a few models of fission fragment penetration in several gases used in fission chambers is presented. To verify the energy loss of fission fragments, a comparison methodology was developed. It is based on comparative analysis of range experiments from third party publications with currently available models. We compared results from the SRIM code, the ICRU parametrization model implemented in Geant-4 and the LSS model. Albeit they are based on different hypotheses about the underlying physics that are not specific to fission fragments, those models reproduce fairly well the trend and order of magnitude of experimental data. Thanks to effective use of semi-empirical correlation fitted over large number of points, the SRIM code gives the closest results to experimental data: thus it is the model of choice for predicting and interpreting fission chambers’ signal.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): V. Cindro, S.H. Abidi, A.A. Affolder, M. Arratia, B. Ciungu, K. Dette, Z. Dolezal, C. Escobar, V. Fadeyev, C. García, I.M. Gregor, K. Hara, L.B.A. Hommels, Y. Ikegai, P. Kodys, G. Kramberger, J. Kroll, C. Lacasta, V. Latonova, D. Madaffari〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Miniature sensors with external dimensions of 10 mm x 10 mm were produced together with full-size sensors for the innermost ring (R0) of the end-cap part in the upgraded ATLAS inner tracker (ITk). AC- and DC-coupled n-type strips with three different pitches (wide, default and narrow) were processed on high-resistivity p-type FZ silicon substrates by Hamamatsu Photonics. The miniature sensors were irradiated with 70-MeV protons at CYRIC, Tohoku University (Japan) and reactor neutrons at the Jožef Stefan Institute (Slovenia) to three different 1-MeV neutron equivalent fluences: 0.5, 1 and 2 x 10〈sup〉15〈/sup〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msub〉〈mrow〉〈mi〉n〈/mi〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉eq〈/mi〉〈/mrow〉〈/msub〉〈/math〉cm〈sup〉−2〈/sup〉. The upper fluence range exceeds the highest anticipated in the innermost part of the ATLAS ITk-Strips over the HL-LHC lifetime (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈mo〉∼〈/mo〉〈/math〉1.25 × 10〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉15〈/mn〉〈/mrow〉〈/msup〉〈/math〉n〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si39.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉eq〈/mi〉〈/mrow〉〈/msub〉〈/math〉cm〈sup〉2〈/sup〉). The charge collection in the test sensors was evaluated systematically using a 〈sup〉90〈/sup〉Sr 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si5.gif"〉〈mi〉β〈/mi〉〈/math〉-source and an Alibava analogue readout system at reverse-bias voltages up to 1000 V.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): P. Cardarelli, G. Paternò, G. Di Domenico, E. Consoli, M. Marziani, M. Andreotti, F. Evangelisti, S. Squerzanti, M. Gambaccini, S. Albergo, G. Cappello, A. Tricomi, M. Veltri, O. Adriani, R. Borgheresi, G. Graziani, G. Passaleva, A. Serban, O. Starodubtsev, A. Variola〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉ELI-NP-GBS is a high-brilliance gamma source that will produce monochromatic beams in the energy range 0.2-19.5 MeV through inverse Compton scattering. In order to obtain a monochromatic beam a collimation of the emission is necessary. Depending on the energy, the angular aperture required to provide the design bandwidth 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉Δ〈/mi〉〈/math〉E/E=0.5% is between 70 and 700 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈mi〉μ〈/mi〉〈/math〉rad. This collimation is provided by a stack of 14 tungsten slits, arranged with a relative rotation around the beam axis, so that the overlap will be a continuously adjustable aperture. To monitor the operation and alignment of the collimation, a set of detectors will provide a complete characterization of the gamma beam, including the measurement of the transverse spatial distribution. For this task a gamma beam profile imager based on a thin scintillator screen and a high-resolution CCD-camera was developed. In this work we briefly present the status of the collimation system and beam profile imager, which were designed, assembled and are currently under test at INFN-Ferrara laboratories.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): N. Buzarbaruah, S.R. Mohanty, E. Hotta〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The adaption of new generation portable neutron sources has been increasingly marked in a wide range of research fields compared to the large-scale neutron generators. In this context, we have successfully demonstrated some essential parameters required for the emission of 2.45 MeV DD fusion neutrons from a steady state portable linear neutron source based on inertial electrostatic confinement scheme. The parameters that control the production of neutrons are the working pressure of the fuel gas, applied voltage, measured current and cathode geometries. The neutrons emitted from the source are confirmed using neutron monitor, bubble dosimeters, nuclear track detectors, and He-3 proportional counter. Presently, the device produces neutrons up to the order of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mo〉∼〈/mo〉〈/math〉 10〈sup〉6〈/sup〉 n/sec at discharge voltage ranging from -60 kV to -80 kV, and discharge current of 20 mA to 30 mA.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Yu.A. Chesnokov, V.A. Maisheev〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The problem of creation of high energy neutrino beams on the basis of modern and future circular proton accelerators with the help of traditional technology seems to be expensive and difficult. Because of this, we propose the solution of this problem based on the usage of focusing bent single crystals. In the paper we demonstrate the possibilities of acceptance and focusing of a pion beam with the help of a crystal optical lens system. As an illustration of these features the calculated neutrino fluxes for energy of circulating proton beam equal to 6.5 TeV are presented.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): L. Werner, M. Trunk, R. Gernhäuser, R. Gilles, B. Märkisch, Zs. Révay〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The cold neutron guide of the Prompt Gamma Activation Analysis (PGAA) instrument (Revay et al. 2015) at the Heinz Maier-Leibnitz Zentrum (MLZ) provides an excellent opportunity for neutron depth profiling (NDP) due to its high collimated neutron flux. We present the concept, layout and first measurements with the new N4DP facility set-up at this beamline. A special focus is put on background analysis and instrument characterization. We present measurements of a NIST reference sample and of boron-containing float glasses which are used for neutron optical waveguides. We give an outlook concerning the ongoing development of position-resolved NDP using silicon microstrip detectors.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Z. Scholz, M. Millett, M. Schell〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Surrogate radiation sources are used to test detection equipment and train security personnel in the detection and interdiction of special nuclear material (SNM). Some current surrogate sources do not accurately match SNM energy spectra, including for HEU. In this research, we propose and investigate novel source configurations for higher fidelity surrogate SNM sources using thermal neutron capture reactions that result in prompt gammas. The objective is to create a surrogate source that has a more representative spectrum, low cost, and requires minimal security, special handling, and safety precautions.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 6 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Ping Yang, Weiping Ren, Xiangming Sun, Guangming Huang, Le Xiao, Chaosong Gao, Xing Huang, Wei Zhou, Yashu Li, Jianchao Liu, Bihui You, Li Zhang, Jun Liu, Ying Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Circular Electron Positron Collider (CEPC) is proposed as a Higgs factory for precision measurement of properties of the Higgs boson. The CEPC vertex detector requires low material budget, high spatial resolution, fast readout and low power consumption. Monolithic Active Pixel Sensor (MAPS), as one of the promising candidate technologies, has been studied within the R&D activities for the CEPC vertex detector. This proceeding introduces recent development of a MAPS prototype using the TowerJazz 180 nm CMOS Image Sensor process. Two different binary front-end circuits have been designed to explore an in-pixel front-end structure suitable for a compact pixel in combination with an in-matrix sparsified readout circuitry. To achieve high granularity together with fast readout speed, a new architecture of asynchronous data-driven matrix readout has been implemented. The prototype contains 128 rows and 64 columns featuring a small pixel pitch of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mn〉25〈/mn〉〈mspace width="1em"〉〈/mspace〉〈mi mathvariant="normal"〉μ〈/mi〉〈mi mathvariant="normal"〉m〈/mi〉〈/math〉. The address of one hit pixel can be read out in 25 ns. This work presents the design of the prototype, which is currently under test.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Seiichi Yamamoto, Hideo Nitta〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gd〈sub〉3〈/sub〉(GaAl)〈sub〉5〈/sub〉O〈sub〉12〈/sub〉:Ce (GGAG) is a ceramic scintillator originally developed for X-ray CT, and it was also an excellent material for the development of an event-by-event-based radiation imaging detector when it was combined with a position sensitive photomultiplier (PSPMT). With the developed GGAG imaging detector, we found that the decay times for alpha particles and gamma photons were different. Also, we found that the decay times for alpha particles and beta particles were different. These characteristics are advantageous for developing an imaging detector for the simultaneous imaging of different types of radiation using pulse shape discrimination. Thus, we tested the separation of the images of the alpha particles and gamma photons using pulse shape discrimination. Also, we evaluated the separation of the alpha and beta particle images. In the pulse shape spectra, we could separate the peaks of Am-241 alpha particles and Cs-137 gamma photons with a peak-to-valley ratio (P/V) of 3.5. We obtained clearly separated images for Am-241 alpha particles and Cs-137 gamma photons using pulse shape discrimination. We could also separate the peaks of Am-241 alpha particles and Sr–Y-90 beta particles with a P/V of 1.5 in the pulse shape spectrum. We obtained separated images for Am-241 alpha particles and Sr–Y-90 beta particles using pulse shape discrimination. In addition, we could separate electrostatically collected natural alpha particles, Po-218 and Po-214, from the environmental beta particles and gamma photons using pulse shape discrimination. We conclude that the GGAG imaging detector is promising for simultaneous imaging and separating the images of different types of radiation using pulse shape discrimination.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 9 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): D. Bernard〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉No 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si64.gif"〉〈mi〉γ〈/mi〉〈/math〉-ray polarimeter sensitive above 1 MeV has ever flown space. 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si64.gif"〉〈mi〉γ〈/mi〉〈/math〉-ray polarimetry would be a new window on the radiative processes at work in cosmic sources, processes that produce linearly polarised emission, each of which with different polarisation fractions. The HARPO Collaboration has designed, built and characterised on beam a gas-TPC active target with which we have demonstrated for the first time the polarimetry of a linearly polarised MeV 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si64.gif"〉〈mi〉γ〈/mi〉〈/math〉-ray beam, from the analysis of the conversions to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si65.gif"〉〈msup〉〈mrow〉〈mi〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉+〈/mo〉〈/mrow〉〈/msup〉〈msup〉〈mrow〉〈mi〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 pairs.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Songqing Tan, Rui Li, Chunlong Guo, Tao Shi, Yongqun Zhao, Xiaopeng Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper proposes a novel input power control strategy for high-power dynamic power supply for proton therapy. A buck chopper is staged in series between the input rectifier and the output chopper of the power supply to buffer the input power fluctuation, which can reduce the reactive power exchange between the power supply and power grid and reduce the power distribution requirements. The validity of this proposed control principle has been verified on a high-power dynamic dipole power supply for proton therapy.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): M. Mallamaci, B. Baibussinov, G. Busetto, D. Corti, A. De Angelis, F. Di Pierro, M. Doro, L. Lessio, M. Mariotti, R. Rando, E. Prandini, P. Vallania, C.F. Vigorito, for the CTA LST project〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A Silicon Photomultiplier (SiPM)-based photodetector is being built to demonstrate its feasibility for an alternative silicon-based camera design for the Large-Sized Telescope (LST) of the Cherenkov Telescope Array. It has been designed to match the size of the standard Photomultiplier Tube (PMT) cluster unit and to be compatible with mechanics, electronics and focal plane optics of the first LST camera. Here, we describe the overall SiPM cluster design along with the main differences with respect to the currently used PMT cluster unit. The fast electronics of the SiPM pixel and its layout are also presented. In order to derive the best working condition for the final unit, we measured the SiPM performances in terms of gain, photo-detection efficiency and cross-talk. One pixel, a unit of 14 SiPMs, has been built. We will discuss also some preliminary results regarding this device and we will highlight the future steps of this project.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 16 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): I. Mattei, G. Battistoni, M. De Simoni, Y. Dong, A. Embriaco, M. Fischetti, E. Gioscio, C. Mancini-Terracciano, M. Marafini, R. Mirabelli, S. Muraro, A. Sarti, A. Sciubba, E. Solfaroli Camillocci, G. Traini, S.M. Valle, V. Patera〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The use of C, He and O as beam particles in Particle Therapy (PT) treatments is getting more and more widespread as a consequence of the enhanced relative biological effectiveness and oxygen enhancement ratio of such projectiles with respect to protons. The advantages in the tumour control probability, related to the improved efficacy of ions, are calling for an online monitor of the dose release spatial distribution. Such technology is currently missing in PT treatments clinical routine. In this contribution the status of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉Z〈/mi〉〈mo〉〉〈/mo〉〈mn〉1〈/mn〉〈/math〉 ions PT treatments monitoring, exploiting the detection of either charged secondary particles or neutrons, is reviewed. While charged fragments can be used to provide an online feedback to the beam control system, by correlating their emission profile with the position of the Bragg peak, neutrons have to be monitored to improve the experimental description of the secondary radiation component that significantly contributes to an undesired and not negligible dose deposition far away from the tumor region, enhancing the risk of secondary malignancies development after the treatment. Two tracker detectors, employing scintillating fibers, are presented: the Dose Profiler designed for charged secondary fragments measurements and the MONDO tracker dedicated to the characterisation of the secondary fast and ultrafast neutron component, within the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Huachang Liu, Jun Peng, Keyun Gong, Ahong Li, Bo Li, Qiang Chen, Xiaolei Wu, Mengxu Fan, Yun Wang, Peihua Qu, Shinian Fu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The China Spallation Neutron Source (CSNS) is an accelerator-based multidisciplinary user facility constructed in Dongguan, Guangdong, China. The injector of the CSNS accelerator consists of 4 conventional Alvarez DTL tanks, and it accelerates an H- beam from 3 MeV to 80 MeV. There is a series of accelerator physics and technology challenges in the DTL design and construction. The transverse focusing is arranged in a FFDD lattice utilizing a newly developed electromagnetic quadrupole magnets. The DTL cavity is copper-plated to enhance the electrical conductivity of the tank inner RF surface. There is not any space for steering magnet installing in the 36 m long DTL section, which leads to a rather high precision requirements for fabrication, installation and RF tuning. Benefited from the advanced fabrication technology and optimized tuning strategy, the CSNS DTL shows an excellent performance in the beam commissioning. The beam is successfully accelerated to 80 MeV with nearly 100% transmissions. The detailed physics and cavity design are described, construction and beam commissioning results are also shown.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Y. Nagata, N. Kuroda, B. Kolbinger, M. Fleck, C. Malbrunot, V. Mäckel, C. Sauerzopf, M.C. Simon, M. Tajima, J. Zmeskal, H. Breuker, H. Higaki, Y. Kanai, Y. Matsuda, S. Ulmer, L. Venturelli, E. Widmann, Y. Yamazaki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An antihydrogen detector consisting of a thin BGO disk and a surrounding plastic scintillator hodoscope has been developed. We have characterized the two-dimensional positions sensitivity of the thin BGO disk and energy deposition into the BGO was calibrated using cosmic rays by comparing experimental data with Monte-Carlo simulations. The particle tracks were defined by connecting BGO hit positions and hits on the surrounding hodoscope scintillator bars. The event rate was investigated as a function of the angles between the tracks and the energy deposition in the BGO for simulated antiproton events, and for measured and simulated cosmic ray events. Identification of the antihydrogen Monte Carlo events was performed using the energy deposited in the BGO and the particle tracks. The cosmic ray background was limited to 12 mHz with a detection efficiency of 81%. The signal-to-noise ratio was improved from 0.22 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉s〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈mn〉1〈/mn〉〈mo〉∕〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 obtained with the detector in 2012 to 0.26 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉s〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈mn〉1〈/mn〉〈mo〉∕〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 in this work.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 9 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): J. Zorn, for the CTA GCT project〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Compact High-Energy Camera (CHEC) is a design option proposed for the small-sized telescopes (SSTs) of the Cherenkov Telescope Array (CTA), focusing on the gamma-ray detection at the upper end of the gamma-ray spectrum (from 1 TeV up to around 300 TeV). Thanks to the use of dual-mirror, Schwarzschild-Couder (SC) optics, CHEC can be – by design – very compact (0.5 m 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mo〉×〈/mo〉〈/math〉 0.5 m), light (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si15.gif"〉〈mo〉∼〈/mo〉〈/math〉50 kg), and low-cost (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si15.gif"〉〈mo〉∼〈/mo〉〈/math〉150€). Using electronics based on TARGET (TeV Array Read-out with GSa/s sampling and Event Trigger) application-specific integrated circuits (ASICs) and field programmable gate arrays (FPGAs) allows a flexible trigger scheme and continuous sampling at 1 GSa/s. Full waveforms for all 2048 pixels are read out without loss at over 600 Hz. Two full prototype cameras have been developed. The first, based on multi-anode photomultipliers (MAPMs) as photosensors, was successfully characterised in the laboratory and during on-telescope campaigns where it saw Cherenkov light from air showers, as the first CTA camera prototype and the first camera ever using SC optics. The second, featuring upgraded ASICs and Silicon photomultipliers (SiPMs), is under commissioning at the Max-Planck-Institut für Kernphysik in Heidelberg.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): S. Abovyan, V. Danielyan, M. Fras, O. Kortner, H. Kroha, R. Richter, Y. Zhao, A. Baschirotto, M. De Matteis, F. Resta〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to fully exploit the physics potential of the ATLAS experiment at the HL-LHC, the trigger rate of and maximum latency of the first-level trigger system will be increased to 1 MHz and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mn〉10〈/mn〉〈mspace width="1em"〉〈/mspace〉〈mi mathvariant="normal"〉μ〈/mi〉〈mi mathvariant="normal"〉s〈/mi〉〈/math〉, respectively. In addition, a new first-level muon track trigger with high momentum resolution based on the ATLAS precision Muon Drift-Tube (MDT) chambers will be employed which requires triggerless readout. The TDC ASICs of the current front-end electronics of the MDT chambers are incompatible with these requirements. The front-end boards, each with a TDC chip and three 8-channel amplifier–shaper–discriminator (ASD) chips have to be replaced. Therefore, a new octal ASD2 ASIC has been developed in modern 130 nm IBM/Global Foundries CMOS technology. The chip also contains a Wilkinson ADC to perform both time-over-threshold and signal charge measurement. The ASD design has been fully qualified for the serial production of 80000 chips for ATLAS. The performance in terms of signal rise time and channel uniformity significantly surpasses the one of the previous chip while keeping the power consumption constant. In addition to the characterization with test pulses, several chips have been mounted on the front-end boards and tested in a muon beam at the Gamma Irradiation Facility GIF++ at CERN up to high counting rates where the superior drift time and spatial resolution becomes evident.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 913〈/p〉 〈p〉Author(s): J.P. Holzbauer, C. Contreras, Y. Pischalnikov, D. Sergatskov, W. Schappert〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉SRF cavity quality factors can be accurately measured using RF-power based techniques only when the cavity is very close to critically coupled. This limitation is from systematic errors driven by non-ideal RF components. When the cavity is not close to critically coupled, these systematic effects limit the accuracy of the measurements. The combination of the complex base-band envelopes of the cavity RF signals in combination with a trombone in the circuit allow the relative calibration of the RF signals to be extracted from the data and systematic effects to be characterized and suppressed. The improved calibration allows accurate measurements to be made over a much wider range of couplings. Demonstration of these techniques during testing of a single-spoke resonator with a coupling factor of near 7 will be presented, along with recommendations for application of these techniques.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Mukhtar Ahmed Rana〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The influence of preservation period of CR-39 detectors, in refrigerator and in the laboratory atmosphere, on bulk etch rate is studied. The effect of etching solution usage time on the bulk etch rate is also investigated. Analyses and quantitative results in the said cases are presented. Finally, precision results on the use of CR-39 as a charged particle detector are presented in a systematic manner. These results are selected from our radiation detection and measurement experiments, ranged over last two decades. Selected results (unpublished and published) include CR-39 measurements of 5.9 MeV antiprotons, 6.12 MeV alpha particles and spontaneous fission fragments of 〈sup〉252〈/sup〉Cf. Our published results, presented here, are further analyzed and presented in comparison with new results and discussion. Experimental procedures of exposures, chemical etching, track measurements using the optical microscopy are described, keeping in view the new users and research students. Computer codes TRACK_Vision and SRIM were employed to provide a comparison with measurements of track parameters, where possible.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 8 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): H. Gómez〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Muon tomography, or muography, stands out as a non-invasive technique for the scanning of big objects internal structure. It relies on the measurement of the direction changes or absorption of atmospheric muons when crossing the studied object. For the first case, the trajectory reconstruction of muons upstream and downstream the object, provides information to generate its 3D density map. For bigger objects, a 2D map can be obtained by measuring the absorption for different incident directions. Proposed several decades ago, the performance achieved in particle detectors in the last years, specially in terms of stability, robustness and precision, has enlarged the possible applications of this technique.〈/p〉 〈p〉Bulk Micromegas represent a well-known technology suitable for the construction of muon telescopes based on these detectors. Thus autonomous and portable instruments have been conceived and constructed at 〈em〉Commissariat à l’Énergie Atomique et aux Énergies Alternatives〈/em〉 (CEA), being able to perform measurements 〈em〉in-situ〈/em〉, next to the studied objects. Furthermore, a Geant4-based simulation framework, capable to handle 3D models of the studied objects, is also being implemented to be used as support tool during the feasibility studies and for data analysis and results interpretation.〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 12 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): B. Canion, J. Dreyer, O. Drury, D. Trombino, K. Nelson, B. Seilhan, S. Labov, K. Jarman, B. McDonald, M. Zalavadia, M. Myjak, D. Pfund, J. Forrester, G. Lawson〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉We investigate a new safeguards approach for verification of uranium processing operations via standoff measurement of UF〈sub〉6〈/sub〉 cylinder transports entering and leaving a facility. Current safeguards verification at facilities with UF〈sub〉6〈/sub〉 cylinders includes attended enrichment measurements of several randomly-selected cylinders using handheld instruments with inspection of all the cylinders typically only once a year. This approach requires significant inspector effort and can only be performed intermittently. Here we explore an unattended, multi-sensor enrichment measurement system that can operate continuously on cylinders in motion. Such an approach could be used to enhance continuity of knowledge by verifying that all shipments entering and leaving a facility are consistent with declared operations.〈/p〉 〈p〉The challenges in developing a standoff enrichment technique include limited statistical significance of the collected data, and interpreting the complex signatures from a shipment of UF〈sub〉6〈/sub〉 cylinders. These signatures vary with cylinder properties (e.g. the fuel cycle history, cylinder history, material distribution, material age, etc.) and measurement conditions (e.g. speed and distance of vehicle, detector response, cylinder orientation, attenuation from overpack and vehicle, etc.).〈/p〉 〈p〉In this paper, we demonstrate that we can extract useful enrichment signatures from standoff measurements of UF〈sub〉6〈/sub〉 cylinders entering and leaving a facility. Our initial analysis demonstrates a measurable difference in enrichment-related signatures from a cylinder in motion, measured with modest detection efficiency from several meters away. We also demonstrate that the inclusion of vehicle tracking increases the signal-to-noise ratio (SNR) of our radiation signatures, and decreases uncertainty of parameters needed for enrichment analysis, e.g. distance and velocity.〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 6 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): G. Matarrese, P.A.P. Calò, F. Corsi, C. Marzocca, S. Petrignani〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉High-gain photomultiplier detectors are employed in an increasing number of applications in different fields to evaluate with great accuracy the occurrence time of light flashes composed by few or even single photons. Examples of these application fields are medical imaging, astroparticle and high energy physics, laser spectroscopy and LIDAR. To fulfill a good single photon timing accuracy, in the range of few hundreds of picoseconds, not only detectors with intrinsic excellent timing resolution (photomultiplier tubes, microchannel plated detectors, silicon photo multipliers, etc.) must be used, but the very first front-end amplifier (FEA) stage, used to read-out the detector, must also be carefully chosen and designed.〈/p〉 〈p〉We compare here three commonly used solutions for the FEA, from the point of view of the best achievable timing resolution: the charge sensitive amplifier (CSA), the voltage amplifier (VA) and the current buffer (CB). The results show that the CSA solution is limited in terms of frequency response by the usually large equivalent capacitance of the detector and that, surprisingly, the presence of the parasitic inductance 〈em〉L〈/em〉, due to interconnection detector-FEA, has a noise shaping effect which favourably affects the timing accuracy of the CB over the VA configuration. To support this study, simulations of simple implementations of the compared FEA solutions have been performed, under the same conditions.〈/p〉 〈p〉Moreover, with reference to a given detector and to a particular value of 〈em〉L〈/em〉, we show how the best timing accuracy of the CB is obtained by selecting an appropriate combination of input resistance and bandwidth of the FEA.〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 5 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): I. Semeniouk, D. Bernard〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present the C++ implementation of an event generator for linearly-polarized gamma-ray conversions to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mi〉γ〈/mi〉〈mo〉→〈/mo〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉+〈/mo〉〈/mrow〉〈/msup〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 pairs. The generator uses the full 5D Bethe–Heitler probability density function for the generation of the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mi〉γ〈/mi〉〈mo〉→〈/mo〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉+〈/mo〉〈/mrow〉〈/msup〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 pair and for the recoil of the target nucleus. The same code is used for triplet generation. We present a verification of the model by comparing sample distributions with theoretical predictions.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): B. Juste, S. Morató, C. García, R. Miró, G. Verdú〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Different methods exist to verify bunkers design for radiation therapy medical facilities; analytical methods based on simplified equations and Monte Carlo methods. One of the main purposes of this work is to present the advantages of using Monte Carlo simulation to verify radiotherapy bunker shielding design. This methodology is more accurate and characterizes not only the fluence and dose three-dimensionally, but also the energy spectrum of particles generated by the LinAc. The other main purpose of the work is to analyze the importance of the generated photoneutrons when the LinAc emits high-energy photon beams (above 8 MeV), since numerous studies have found that these neutrons can expose the patient and clinical staff to non-negligible dose. The main novelty introduced by this work, is the creation of more realistic geometry simulation models to represent the radiotherapy facility by using CAD and meshes technologies which can be imported to MCNP6 Monte Carlo code. Results obtained using these bunker simulation models have been validated experimentally at the Hospital Universitari i Politècnic La Fe de Valencia facilities using two different neutron detectors; the neutron meter LB 6411 (designed between Berthold and Karlsruhe Research Center) and neutron detector model 42 - 41L (Ludlum, Prescila). Neutron dose results obtained with Monte Carlo and those measured experimentally fit correctly, validating this analysis methodology.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 9 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): L. Wiik-Fuchs, L. Diehl, R. Mori, M. Hauser, K. Jakobs, S. Kühn, U. Parzefall, A.A. Affolder, V. Fadeyev, C. García, C. Lacasta, D. Madaffari, U. Soldevila, Y. Unno〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The upgrade of the LHC to the High Luminosity LHC will challenge the silicon strip detector performance with high fluence and long operation time. Sensors have been designed and tests on charge collection and electrical performance have been carried out in order to evaluate their behaviour. Besides that, it is important to understand and predict the long-term evolution of the sensor properties. In this work, detailed studies on the annealing behaviour of ATLAS12 strip sensors designed by the ITK Strip Sensor Working Group and irradiated from 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mn〉5〈/mn〉〈mo〉×〈/mo〉〈mn〉1〈/mn〉〈msup〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mrow〉〈mn〉13〈/mn〉〈/mrow〉〈/msup〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉n〈/mi〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉eq〈/mi〉〈/mrow〉〈/msub〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉cm〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈mn〉2〈/mn〉〈mo〉×〈/mo〉〈mn〉1〈/mn〉〈msup〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mrow〉〈mn〉15〈/mn〉〈/mrow〉〈/msup〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉n〈/mi〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉eq〈/mi〉〈/mrow〉〈/msub〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉cm〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 are presented. Systematic charge collection and leakage current measurements have been carried out during the annealing process until break-down or the appearance of charge multiplication. The annealing was carried out, separating the sensors into two groups being either annealed at 23 °C or 60 °C. Sensors showing charge multiplication have been then kept at high voltage for a long time in order to monitor their stability. The difference in the annealing behaviour between the two temperatures has been analysed and compared to similar measurements on n-type sensors and with a theoretical model. From the impedance measurements for the samples irradiated to low fluences it was possible to extract the effective doping concentration. This was compared to similar measurements on n-type sensors and with a theoretical model.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 9 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Carlos Granja, Karel Kudela, Jan Jakubek, Pavel Krist, David Chvatil, Jan Stursa〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We evaluate and characterize the directional response of the semiconductor pixel detector Timepix to charged particles and secondary cosmic rays. The detector granularity and per-pixel spectrometric response enable to perform directional sensitive tracking of energetic charged particles in wide field-of-view. In the highly integrated MiniPIX readout the detector serves as a miniaturized, low-power and easily deployable particle micro-tracker. Angular measurements require normalization for the acceptance angle and geometric factor which are described and taken into account. The methodology and evaluation of directional response are developed for light charged particles and atmospheric secondary cosmic rays. Tests and calibration of angular resolution were performed with electron and proton beams. Resulting angular distributions are expressed in terms of elevation and azimuth angles in 14 bins and 36 bins, respectively, over the full 2〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉π〈/mi〉〈/math〉 acceptance range. For zenith angle 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si17.gif"〉〈mi〉β〈/mi〉〈/math〉 〉 28° the angular distribution is fitted by 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mo〉∼〈/mo〉〈/math〉 cos 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉n〈/mi〉〈/mrow〉〈/msup〉〈/math〉 (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si17.gif"〉〈mi〉β〈/mi〉〈/math〉) with n = 2.0 ± 0.2 expected from secondary cosmic ray muon distribution.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): G. Mauri, M. Mariotti, F. Casinini, F. Sacchetti, C. Petrillo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The application of Si sensors coupled to Gd converters as thermal neutron counters is assessed in a series of test experiments on the neutron beam, among which scattering from standard samples. The prototype 1d detector is a Si microstrip sensor directly coupled to natural Gd converter and equipped with standard front-end electronics. The raw scattering data, collected by interfacing the detector with the data acquisition system available at the neutron source, show advantages and limits of this technology when applied to neutron detection. To improve the performances of the Si-based detector by means of an optimized discrimination of the neutron signals from noise and background radiation, a pulse shape analysis method is proposed. The effectiveness of this method is then explored by experimental tests on the neutron beam of two more prototype detectors, namely a PIN diode coupled to   〈sup〉157〈/sup〉Gd〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si138.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/math〉O〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si139.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉3〈/mn〉〈/mrow〉〈/msub〉〈/math〉 converters, and a Silicon photo-multiplier (SiPM) coupled to neutron scintillators. This study is aimed to real time applications and single event storage of the neutron information in time of flight instrumentation.〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 296〈/p〉 〈p〉Author(s): Kadir Tuna, Arnd Kilian, Thorsten Ressler〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electroless plating of tin layers with thicknesses of more than 3 μm is becoming an important process in the production of circuit boards and semiconductor. Phosphonates constitute promising complexing agents for autocatalytic tin electrolytes. However, detailed time-resolved investigations or electrochemical impedance spectroscopy (EIS) measurements of tin deposition in this system are lacking. Here, deposition of tin was investigated by electrochemical quartz microbalance (EQCM) and electrochemical impedance spectroscopy. EQCM investigations showed a strong drop in deposition rate within the first ten minutes. Bath parameters had a significant effect on the drop of deposition rate. The results indicated an inhibitive pyrophosphate adsorption on the tin electrode surface which caused the observed drop of deposition rate. Impedance measurements confirmed this assumption. The equivalent circuit applied for the analysis of EIS data, included an increasing adsorbate resistance Rp, which can be related to the thickness of an adsorbed permeable pyrophosphate layer. Impedance measurements at selected frequencies revealed a linear relation between deposition rate and conductance 1/Rp. Subsequently, gluconate substituting for pyrophosphate was tested as complexing agent. Combined EQCM and EIS measurements during deposition using a gluconate containing electrolyte showed a stable rate with an invariant conductance.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 295〈/p〉 〈p〉Author(s): Tao Liu, Xiaolin Sun, Shimei Sun, Quanhai Niu, Hui Liu, Wei Song, Fengting Cao, Xichao Li, Takeo Ohsaka, Jianfei Wu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lithium-sulfur batteries were investigated as promising next-generation energy storage devices owing to their high capacity in comparison to conventional lithium-ion batteries. Nevertheless, the serious shuttle effect and sluggish redox kinetics originated from dissolution of polysulfides and insulating property of sulfur and lithium sulfide, restricted their practical applications. To overcome these stubborn problems, a robust and environment-friendly biomass carbon fiber interlayer anchored with uniformly-distributed SiO〈sub〉2〈/sub〉 nanoparticles was demonstrated. Benefiting from the excellent conductivity of carbon fiber, together with the stable chemical adsorption of SiO〈sub〉2〈/sub〉 for soluble polysulfides, this low-cost and lightweight interlayer could not only remarkably enhance sulfur utilization, but also efficiently capture the polysulfides by chemical entrapment strategies. With this biomass carbon fiber@SiO〈sub〉2〈/sub〉 interlayer, the batteries delivered a high reversible capacity of 1352.8 mAh g〈sup〉−1〈/sup〉 at 0.1 C and enhanced capacity of 618.4 mAh g〈sup〉−1〈/sup〉 after 500 cycles at 1.0 C. Even up to 4.2 mg cm〈sup〉−2〈/sup〉 sulfur loading, high cycling stability was also achieved by this interlayer. We believe this robust and low-cost interlayer has a great potential for practical applications of Li–S batteries.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Jaime Rodríguez-Estival, Marta I. Sánchez, Cristina Ramo, Nico Varo, Juan A. Amat, Juan Garrido-Fernández, Dámaso Hornero-Méndez, Manuel E. Ortiz-Santaliestra, Mark A. Taggart, Mónica Martinez-Haro, Andy J. Green, Rafael Mateo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉European populations of black-necked grebes (〈em〉Podiceps nigricollis〈/em〉) congregate every year to moult at the salt ponds of the Odiel Marshes (SW Spain). However, the Odiel Marshes are part of one of the most metal-polluted coastal estuaries in the world, which may pose risks to wildlife. We assessed the exposure of grebes to metal pollution during the critical moulting period in the Odiel Marshes and its potential to cause adverse health effects. Levels of metals in red blood pellet (as a biomarker of exposure), plasma carotenoids, eye redness, and body condition (as biomarkers of effects) were studied. Metal content was also analyzed in the brine shrimp 〈em〉Artemia parthenogenetica〈/em〉, the most important food for grebes in this hypersaline ecosystem during the moulting period. Results showed that, in comparison to toxicity thresholds, grebes had relatively high blood levels of arsenic (As), mercury (Hg) and zinc (Zn). The high loads found in 〈em〉Artemia〈/em〉 and the way blood levels vary during the moulting period indicate that shrimp consumption may be the main route of metal exposure for grebes. Plasma carotenoids and body condition showed a positive association with exposure to As, while the relationship of lutein-like carotenoids with Hg accumulation was negative at the beginning of the moulting period to become positive afterwards. Moreover, eye redness was negatively affected by As accumulation. Factors including food resource availability, seasonal fluctuations in physiological status, and interannual variations in the degree of environmental contamination should be considered in monitoring efforts when using moult migrant waterbirds as sentinel species.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S004565351832006X-egi108SW54GQSP.jpg" width="355" alt="Image" title="Image"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Hong Wang, Zhiqiu Gao, Jingzheng Ren, Yibo Liu, Lisa Tzu-Chi Chang, Kevin Cheung, Yun Feng, Yubin Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study investigates the urban-rural and sex differences in the increased risks of the ten most common cancers in China related to high PM〈sub〉2.5〈/sub〉 concentration in the southeastern side of Hu line. Pearson correlation coefficient is estimated to reveal how the cancers closely associated with PM〈sub〉2.5〈/sub〉 long-term exposure. Then linear regression is conducted to evaluate sex- and area-specific increased risks of those cancers from high level PM〈sub〉2.5〈/sub〉 long-term exposure. The major finding is with the increase of every 10 μg/m〈sup〉3〈/sup〉 of annual mean PM〈sub〉2.5〈/sub〉 concentration, the increase of relative risks for lung cancer incidence and mortality are 15% and 23% for males, and 22% and 24% for females in rural area. For urban area, the increase of relative risk for ovarian cancer incidence is 9% for females, while that for prostatic cancer increases 17% for males. For leukemia, the increase of relative risks for incidence and mortality are 22% and 19% for females in rural area, while in urban area the increase of relative risk for mortality is 9% for males and for incidence is 6% for females. It is also found that with increased PM〈sub〉2.5〈/sub〉 exposure, the risks for ovarian and prostatic cancer rise significantly in urban area, while risks for lung cancer and leukemia rise significantly in rural area. The results demonstrate the higher risks for lung cancer and leukemia with increased PM〈sub〉2.5〈/sub〉 exposure are more significant for female. This study also suggests that the carcinogenic effects of PM〈sub〉2.5〈/sub〉 have obvious sex and urban-rural differences.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Yanju Liu, Jianhua Du, Zhaomin Dong, Mohammad Mahmudur Rahman, Yongchao Gao, Kaihong Yan, Ravi Naidu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉There is increasing concern about the use of chromated copper arsenate (CCA) treated timber due to the possible leaching of toxic metals or metalloids. CCA-treated timber waste are currently stockpiled across Australia with limited information about their risks to the environment or human health. In this study, the treatment and utilisation of CCA-treated timber waste as garden mulch, garden retaining walls, and soil additive were investigated. Iron materials were used as immobilising agents. The bioavailability of Cr, Cu and As to 〈em〉Spinacia oleracea〈/em〉 from CCA-treated timber, before and after treatment, was determined in the context of human health risk assessment. The results showed that the iron-based treatments resulted in significant decreases in the concentrations of Cu and As in spinach grown in CCA-treated timber in soil. Analyses of CCA derived Cu and As in spinach showed that they accumulated in the roots rather than in the leaves. The risks of toxicity to humans varied for different utilisation scenarios and the immobilisation amendments were shown to reduce carcinogenic and non-carcinogenic risks. The information obtained in this study can inform development of utilisation options for CCA-treated timber wastes.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320022-fx1.jpg" width="307" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Han Chen, Tao Lin, Wei Chen, Hui Tao, Hang Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The variations of disinfection byproduct (DBP) precursors and DBPs-associated toxic potencies were evaluated by ozonation, followed by a up-flow biological activated carbon (O〈sub〉3〈/sub〉/UBAC) filter treating two reconstituted water samples, featuring either high bromide (105.3 μg/L) or dissolved organic nitrogen (0.73 mg N/L) concentration, respectively. Ozonation contributed to ∼20% decrease in dissolved organic carbon (DOC) concentration at a dosage of 0.7 mg of O〈sub〉3〈/sub〉/mg of DOC, but no further reduction in DOC level was observed with an increased dose of 1.0 mg of O〈sub〉3〈/sub〉/mg of DOC. When chlorine or preformed monochloramine was used as a disinfectant, UBAC process led to ∼40% reduction in the sum of detected DBP formation potential (FP) due to the removal of precursors at a feasible empty bed contact time of 15 min. The integrated effect of ozonation and UBAC biofiltration decreased the sum of DBP FP by ∼50% including halonitromethanes (THNMs), N-nitrosamines (NAs), and bromate, which increased in the effluent of ozonation. Chloramination produced less DBPs by weight as well as DBPs-associated additive toxic potencies than chlorination. The reduction in additive toxic potencies was generally lower than the removal efficiency of DBP FP after chlor(am)ination of treated waters by O〈sub〉3〈/sub〉/UBAC, indicating that the removal of DBPs-associated additive toxic potencies should be focused to better understand on the residual risk to public health in controlling DBP precursors.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518319064-fx1.jpg" width="273" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Brooke K. Mayer, Carlan Johnson, Yu Yang, Nicole Wellenstein, Emily Maher, Patrick J. McNamara〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study evaluated strategies targeting macro- and micro-organic contaminant mitigation using low-energy titanium dioxide photocatalysis. Energy inputs of 1, 2, and 5 kWh m〈sup〉−3〈/sup〉 resulted in incomplete oxidation of macro-organic natural organic matter, signified by greater reductions of UV〈sub〉254〈/sub〉 and specific ultraviolet UV absorbance (SUVA) in comparison to dissolved organic carbon (DOC). The rate of UV〈sub〉254〈/sub〉 removal was 3 orders of magnitude greater than the rate of DOC degradation. Incomplete oxidation improved operation of downstream filtration processes. Photocatalysis at 2 kWh m〈sup〉−3〈/sup〉 increased the bed life of downstream granular activated carbon (GAC) filtration by 340% relative to direct filtration pretreatment. Likewise, photocatalysis operated ahead of microfiltration decreased fouling, resulting in longer filter run times. Using 2 kWh m〈sup〉−3〈/sup〉 photocatalysis increased filter run time by 36 times in comparison to direct filtration. Furthermore, levels of DOC and UV〈sub〉254〈/sub〉 in the membrane permeate improved (with no change in removal across the membrane) using low-energy photocatalysis pretreatments. While high-energy UV inputs provided high levels of removal of the estrogenic micro-organics estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynlestradiol (EE2), low-energy photocatalysis did not enhance removal of estrogens beyond levels achieved by photolysis alone. In the cases of E1 and E3, the addition of TiO〈sub〉2〈/sub〉 as a photocatalyst reduced degradation rates of estrogens compared to UV photolysis. Overall, process electrical energy per order magnitude reductions (EEOs) greatly improved using photocatalysis, versus photolysis, for the macro-organics DOC, UV〈sub〉254〈/sub〉, and SUVA; however, energy required for removal of estrogens was similar between photolysis and photocatalysis.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320885-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): Rahat Riaz, Usman Ali, Jun Li, Gan Zhang, Khan Alam, Andrew James Sweetman, Kevin C. Jones, Riffat Naseem Malik〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lesser Himalayan Region (LHR) is an important mountain ecosystem which supports a wide range of biodiversity for native flora and fauna. Human population in this region is largely dependent upon local sources for their livelihood. Surface soil (n = 32) and sediment (n = 32) were collected from four different altitudinal ranges of LHR and analyzed for priority Polycyclic Aromatic Hydrocarbons (PAHs) recommended by USEPA. Level, sources and distribution pattern of PAHs were assessed in soil and sediments samples collected from four altitudinal zones in LHR. Total PAHs concentration level of PAHs in soil and sediments ranged from 62.79 to 1080 ng g〈sup〉−1〈/sup〉 and 14.54–437.43 ng g〈sup〉−1〈/sup〉, respectively. Compositional profile of PAHs in both soil and sediment were dominated by low and medium molecular weight PAHs, ranged from 18.02 to 402.18 ng g〈sup〉−1〈/sup〉in soil and 0.32–96.34 ng g〈sup〉−1〈/sup〉in sediments. In the context of spatial distribution trend, highest mean concentrations of PAHs in soil were recorded in zone D (sites from the rural region) and for sediments highest concentrations were detected at zone A, which includes dam sites. In all four zones, no altitudinal trend of PAHs in soil and sediments was observed. Source apportionment through receptor modelling by positive matrix factorization (PMF) revealed that local sources such as biomass combustion and vehicular emissions are important sources of PAHs in this region. The prevalence of monsoon atmospheric circulation system in LHR implicated that this region is also influenced by medium and long range atmospheric transportation of PAHs from neighboring countries where potential sources and high level of PAHs has been reported.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518320009-fx1.jpg" width="357" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Xiaohui Zhang, Song Tang, Mao Wang, Weimin Sun, Yuwei Xie, Hui Peng, Aimin Zhong, Hongling Liu, Xiaowei Zhang, Hongxia Yu, John P. Giesy, Markus Hecker〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Acid mine drainage (AMD) is one of the most hazardous byproducts of some types of mining. However, research on how AMD affects the bacterial community structure of downstream riverine ecosystems and the distribution of metal resistance genes (MRGs) along pollution gradient is limited. Comprehensive geochemical and high-throughput next-generation sequencing analyses can be integrated to characterize spatial distributions and MRG profiles of sediment bacteria communities along the AMD-contaminated Hengshi River. We found that (1) diversities of bacterial communities significantly and gradually increased along the river with decreasing contamination, suggesting community composition reflected changes in geochemical conditions; (2) relative abundances of phyla 〈em〉Proteobacteria〈/em〉 and genus 〈em〉Halomonas〈/em〉 and 〈em〉Planococcaceae〈/em〉 that function in metal reduction decreased along the AMD gradient; (3) low levels of sediment salinity, sulfate, aquatic lead (Pb), and cadmium (Cd) were negatively correlated with bacterial diversity despite pH was in a positive manner with diversity; and (4) arsenic (As) and copper (Cu) resistance genes corresponded to sediment concentrations of As and Cu, respectively. Altogether, our findings offer initial insight into the distribution patterns of sediment bacterial community structure, diversity and MRGs along a lotic ecosystem contaminated by AMD, and the factors that affect them.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S004565351832085X-fx1.jpg" width="437" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Kenneth Brezinski, Beata Gorczyca〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Natural organic matter (NOM) constitutes the terrestrial and aquatic sources of organic plant like material found in water bodies. As of recently, an ever-increasing amount of effort is being put towards developing better ways of unraveling the heterogeneous nature of NOM. This is important as NOM is responsible for a wide variety of both direct and indirect effects: ranging from aesthetic concerns related to taste and odor, to issues related to disinfection by-product formation and metal mobility. A better understanding of NOM can also provide a better appreciation for treatment design; lending a further understanding of potable water treatment impacts on specific fractions and constituents of NOM. The use of high performance size-exclusion chromatography has shown a growing promise in its various applications for NOM characterization, through the ability to partition ultraviolet absorbing moieties into ill-defined groups of humic acids, hydrolysates of humics, and low molecular weight acids. HPSEC also has the ability of simultaneously measuring absorbance in the UV–visible range (200–350 nm); further providing a spectroscopic fingerprint that is simply unavailable using surrogate measurements of NOM, such as total organic carbon (TOC), ultraviolet absorbance at 254 nm (UV〈sub〉254〈/sub〉), excitation-emission matrices (EEM), and specific ultraviolet absorbance at 254 nm (SUVA〈sub〉254〈/sub〉). This review mainly focuses on the use of HPSEC in the characterization of NOM in a potable water setting, with an additional focus on strong-base ion-exchangers specifically targeted for NOM constituents.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518318824-fx1.jpg" width="474" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 216〈/p〉 〈p〉Author(s): John Pierce Wise, James T.F. Wise, Catherine F. Wise, Sandra S. Wise, Cairong Zhu, Cynthia L. Browning, Tongzhang Zheng, Christopher Perkins, Christy Gianios, Hong Xie, John Pierce Wise〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉One Environmental Health has emerged as an important area of research that considers the interconnectedness of human, animal and ecosystem health with a focus on toxicology. The great whales in the Gulf of Maine are important species for ecosystem health, for the economies of the Eastern seaboard of the United States, and as sentinels for human health. The Gulf of Maine is an area with heavy coastal development, industry, and marine traffic, all of which contribute chronic exposures to environmental chemicals that can bioaccumulate in tissues and may gradually diminish an individual whale's or a population's fitness. We biopsied whales for three seasons (2010–2012) and measured the levels of 25 metals and selenium in skin biopsies collected from three species: humpback whales (〈em〉Megaptera novaeangliae〈/em〉), fin whales (〈em〉Balaenoptera physalus〈/em〉), and a minke whale (〈em〉Balaenoptera acutorostrata〈/em〉). We established baseline levels for humpback and fin whales. Comparisons with similar species from other regions indicate humpback whales have elevated levels of aluminum, chromium, iron, magnesium, nickel and zinc. Contextualizing the data with a One Environmental Health approach finds these levels to be of potential concern for whale health. While much remains to understand what threats these metal levels may pose to the fitness and survival of these whale populations, these data serve as a useful and pertinent start to understanding the threat of pollution.〈/p〉〈/div〉 〈/div〉