ALBERT

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): S.P. Sun, J.L. Zhu, S. Gu, X.P. Li, W.N. Lei, Y. Jiang, D.Q. Yi, G.H. Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The surface stability and equilibrium morphology of MoO〈sub〉3〈/sub〉 were investigated by the first principles calculations. The thermodynamic energies of the stoichiometric surfaces of MoO〈sub〉3〈/sub〉 are in the order (0 1 0) 〈 (1 0 1) 〈 (0 0 1) 〈 (1 0 0). It is found that the (0 1 0) surface has a lowest surface energy, which agrees well with the previous calculations. The energies of the non-stoichiometric surfaces were evaluated as functions of temperature and oxygen partial pressure. The results show that the energies of Mo-terminated surfaces decrease with temperatures, and increase with oxygen partial pressures, while the energies of O-terminated surfaces show the opposite rule. The equilibrium morphology of MoO〈sub〉3〈/sub〉 was predicted by using the Gibbs-Wulff model, and then was compared with the other’s experiments and theoretical results.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Sanju Gupta, Nicholas Dimakis〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interfacial interactions between transition metal oxides (vanadium oxide VO〈sub〉2〈/sub〉, vanadium pentoxide V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉, cobalt oxide CoO and Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉, manganese oxide MnO〈sub〉2〈/sub〉) and water adsorbates on graphene supports as solvated interfaces and influence of defects in graphene are studied using periodic density functional theory (DFT) calculations in view of their significance for applied electrochemistry. DFT complemented and synergized our experimental work. The optimized metal oxide adatom-graphene geometries identified the preferred adatom sites, whereas metal oxide-graphene strengths are correlated with the adatom distance from the graphene plane, the Metal-C overlap populations, and the adsorption energies. The presence of finite electronic density of states (DOS) near Fermi level and charge transfers between the adatom top layer and graphene supports reflect primarily covalent bonding nature. The presence of small orbital overlap integral of bonds between the s and p (and d) orbitals of the nearest carbon (graphene), carbon oxide (graphene oxide) and metal oxide atoms reveal localized orbital re-hybridization resulting in changes in DOS yielding high electrochemical activity. Moreover, for increased adatom coverage the extent of charge transfer reverses resulting in limited electroactivity. In fact, DFT calculations are corroborated with experimental findings, where graphene-based supports decorated with optimal mass loaded nanostructured Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 and MnO〈sub〉2〈/sub〉 (as well as V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉) were capable of delivering maximum specific energy storage capacity (C〈sub〉s〈/sub〉) 〉 550 F·g〈sup〉−1〈/sup〉 (Gupta et al. J. Mater. Res. 32, 301 (2017)) in contrast to higher or lower loading. The presence of defects in graphene materials results in new electronic states to endow unique functionalities that is not otherwise possible in the bulk and with adsorbed water molecules besides optimum C/O ratio in graphene oxide nanosheets that show redshift thus a decreasing bandgap and finite charge transfer from graphene to water molecules. The case examples studied in this work represent a first glimpse of what may become routine and integral step in materials design and discovery for alternative energy and sustainable environmental technologies.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Xu Wu, Yalin Feng, Yali Du, Xuezhen Liu, Chunlei Zou, Zhe Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉LDHs templates (marked as CoAl-MnO〈sub〉2〈/sub〉-LDH and CoMnAl-CO〈sub〉3〈/sub〉-LDH) were fabricated via ion-exchange/redox reaction and hexamethylenetetramine (HMT) hydrolysis methods respectively. CoMnAl mixed metal oxides (marked as MnO〈sub〉2〈/sub〉/CoAl-LDO and CoMnAl-LDO) from the as-prepared LDHs templates were novelly prepared and tested as low-temperature NH〈sub〉3〈/sub〉-SCR catalysts. Catalytic evaluation pronouncedly affirmed that the catalytic performances of the as-acquired catalysts were vulnerable to the preparation method of precursor template, where MnO〈sub〉2〈/sub〉/CoAl-LDO presented preferable DeNOx activity (over 90% NOx conversion), N〈sub〉2〈/sub〉 selectivity and SO〈sub〉2〈/sub〉 resistance in much broader working temperature window (90–300 °C) than CoMnAl-LDO. Multiple characterizations revealed that the excellent catalytic performance of the MnO〈sub〉2〈/sub〉/CoAl-LDO could be attributed to its higher specific surface area which could promote dispersion of abundant Mn〈sup〉4+〈/sup〉 and Co〈sup〉3+〈/sup〉 species, and resultantly afforded stronger redox ability and more acid sites. Moreover, dynamic calculation confirmed that the relatively lower activation energy on MnO〈sub〉2〈/sub〉/CoAl-LDO for low-temperature NH〈sub〉3〈/sub〉-SCR reaction should be closely related to the occurrence of a more rapid redox cycle and in agreement with the excellent DeNOx performance.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329702-ga1.jpg" width="413" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Sandra Jendrzej, Leonard Gondecki, Jörg Debus, Henning Moldenhauer, Peter Tenberge, Stephan Barcikowski, Bilal Gökce〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The lubricant is a central element in the transmission design. It primarily separates the two contact partners through a pressure-induced solidification in the lubrication gap, thus enabling the operation of heavily loaded sliding-rolling contacts. On the one hand, the quality and properties of a lubricant depend on the base oils, which differ by their viscosity and process-technological parameters. The addition of particulate additives gives the lubricants further functional properties that are not contained in the base oil. In this study, the influence of laser-synthesized yttria-stabilized zirconia nano- or submicrometer spheres as dispersed functional elements in the lubricant is studied, and their impact on wear and fatigue on the tooth flank is investigated. The work includes systematic investigations on the influence of the particle’s shape and size by running tests on a FZG gear test rig. Finally, the potential of the laser-generated particles as a lubricant additive is evaluated in a first conclusion.〈/p〉〈/div〉 〈/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: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering〈/p〉 〈p〉Author(s): Vladimir A. Osinov, Stylianos Chrisopoulos, Theodoros Triantafyllidis〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The paper presents a numerical analysis of the dynamic deformation of the tunnel lining and the soil caused by a blast-induced pressure pulse of a moderate amplitude (several megapascals) inside the tunnel. The tunnel lining is circular and consists of individual concrete linearly elastic tubbings. The tunnel is located at a depth of 15 m in fully saturated granular soil. Effective-stress changes are described by a hypoplasticity model. The possibility of pore water cavitation at zero absolute pore pressure is taken into account. The problem is solved in a two-dimensional plane-strain formulation with the finite-element program Abaqus/Standard. Emphasis is placed on fine spatial discretization in order to obtain accurate solutions. Stresses and deformations in the lining and in the soil are analysed in detail. The solutions reveal an important role of the strong nonlinearity in the soil behaviour due to the pore water cavitation.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Cong Chen, Shouzhen Bao, Baoshun Zhang, Ying Chen, Wen Chen, Chengyu Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To reduce electromagnetic interference (EMI) and irradiation, one efficient path is to develop electromagnetic absorption (EMA) material with the aim of high-efficient convert electromagnetic wave into thermal energy. Presently strategy to design high-performance electromagnetic absorber is followed by the way of component optimization and microstructure design. This research reported an advanced HWCNTs/Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 ternary absorber, which was fabricated by decorating H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 treated carbon nanotubes (HCNTs) with magnetic core-shell shaped Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanoparticles. This HCNTs/Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 composite exhibits various electromagnetic loss forms, including conductive, dipole, interface loss 〈em〉etc〈/em〉. which attribute to EMA ability. The largest qualified frequency width (〈em〉f〈sub〉E〈/sub〉〈/em〉) can up to 5.4 GHz with a thickness of 1.5 mm. To discuss the EMA loss mechanism, control experiments have been conducted by preparation of Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉, HCNTs@Fe@Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 composites. In this way, the attenuation mechanism can be better understood.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329179-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Gang Yuan, Xiao Zhao, Yeru Liang, Lin Peng, Hanwu Dong, Yong Xiao, Chaofan Hu, Hang Hu, Yingliang Liu, Mingtao Zheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a new class of zero-dimensional carbon nanomaterials, carbon dots have triggered intensive research interest in various fields. However, the low surface area, hydrophilicity, and agglomeration characteristics limit their applications in energy storage fields. Herein, we demonstrate that nitrogen-doped carbon dots can be employed as efficient nanoenhancer to boost the electrochemical performance of three-dimensional graphene. The as-prepared materials exhibit an interconnected framework with abundant oxygen- and nitrogen-containing functional groups, which enable fast penetration and transport of electrolyte ions and provide more active sites and electric conductivity. Employed as binder-free electrode for supercapacitors, the resultant materials present high specific capacitance (338 F g〈sup〉−1〈/sup〉) and areal capacitance (604 μF cm〈sup〉−2〈/sup〉) at a current density of 0.5 A g〈sup〉−1〈/sup〉, which is much higher than that of pristine three-dimensional graphene (190 F g〈sup〉−1〈/sup〉, and 114 μF cm〈sup〉−2〈/sup〉), with an enhancement of 78% and 430%, respectively. Moreover, superior long-term cycling stability (94% of capacitance retention after 20 000 charging/discharging cycles at 10 A g〈sup〉−1〈/sup〉) as well as improved electric conductivity can also be achieved. These results certify that nitrogen-doped carbon dots can be applied as nanobooster to comprehensively improve the performance of graphene for high-performance electrochemical energy storage.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Small nitrogen-doped carbon dots (〈em〉N〈/em〉-CDs) are employed as efficient nanoenhancer to significantly boost the electrochemical performances of three-dimensional graphene (3DG) for supercapacitors.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312931-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Yuanyuan Zhang, Lili Wang, Fengying Dong, Qiao Chen, Haiyan Jiang, Mei Xu, Jinsheng Shi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉-based ternary composite materials are generally synthesized by two- or multi-step method and special precursor of CO〈sub〉3〈/sub〉〈sup〉2−〈/sup〉 is usually utilized in synthesis of Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉, which are time-consuming, laborious and relatively costly. In this paper, for the first time, a facile one-step solvothermal method is used to fabricate Z-scheme Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉/Bi/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 ternary composites. Interestingly, ethylene glycol not only acts as solvent for the reaction system, but also reduced Bi〈sup〉3+〈/sup〉 into metallic Bi and itself is oxidized to CO〈sub〉3〈/sub〉〈sup〉2−〈/sup〉, which could construct Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉. On this occasion, Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉/Bi/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 ternary composites are obtained after one-step method. High resolution transmission electron microscopy clearly reveals each component in composites. The as-prepared samples could be applied in various photocatalytic activities. Under solar light irradiation, Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉/Bi/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 composites exhibited prominent photodegradation performances for both ciprofloxacin and bisphenol A. Meanwhile, these composites could also be used in efficient photoreduction of CO〈sub〉2〈/sub〉. The efficient photocatalytic activity could be mainly ascribed to Z-scheme electron transfer mechanism in ternary composites, which is determined by surface redox reactions, active species trapping experiment, electron spin resonance spectrum.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312918-ga1.jpg" width="425" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Hua Guo, Ya Su, Yanling Shen, Yumei Long, Weifeng Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Optimizing heterostructure of nanocomposites holds great potential for making full use of their ability. Herein, gold nanoparticles (AuNPs) were in situ synthesized over the surface of graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) via one-step pyrolyzation route using a single source precursor. The precursor of melamine chloroauric (C〈sub〉3〈/sub〉H〈sub〉6〈/sub〉N〈sub〉6〈/sub〉H〈sup〉+〈/sup〉⋅AuCl〈sub〉4〈/sub〉〈sup〉−〈/sup〉) was obtained through chemical precipitation reaction between melamine and chloroauric acid. The morphological analysis confirmed the compact contact between Au nanoparticles and g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. Then, the Au-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanocomposites were employed to fabricate electrochemical sensor by modifying glassy carbon electrode (GCE). Electrochemical experiments showed that the Au-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 exhibited enhanced electrocatalytic activity towards tetracycline oxidation as compared with either pure g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 or Au nanoparticles. Based on cyclic voltammetry (CV) method, the sensor was applied in the detection of tetracycline with a low detection limit of 0.03 μM (S/N = 3) and the linear range of concentration were 0.1–20 μM and 20–200 μM, respectively. Moreover, such an electrochemical sensor demonstrated high stability and good selectivity. Finally, the electrochemical sensor was applied to drug assays and exhibited sufficient precision and accuracy. Therefore, this work paves a new way of preparing g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉–based heterostructures and provides an efficient method for the detection of tetracycline in clinical analysis and quality control.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718313018-ga1.jpg" width="419" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Mingmei Zhang, Hong Liu, Ying Wang, Tianjiao Ma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three-dimensional (3D) flower center/petal nanostructure exhibits excellent electrochemical performance because of their unique unfold ultra-thin multi-layer structure benefit to the rapid transmission of electrons and the full infiltration of the electrolyte. A three-phase Fe〈sub〉5〈/sub〉Ni〈sub〉4〈/sub〉S〈sub〉8〈/sub〉 nanosflower is constructed by one step alcohothermal technique using a mixture solvent of glycerol, diethylene glycol and ethylenediamine. Ethylenediamine successfully functions as the complexing agent of metal ions to slowly release the metal ions in the process of reaction, which encourage the flower petal nanostructure formation. Interestingly, when the proportion of iron increased, a novel Fe〈sub〉7〈/sub〉S〈sub〉8〈/sub〉@Fe〈sub〉5〈/sub〉Ni〈sub〉4〈/sub〉S〈sub〉8〈/sub〉 flower center/petal nanostructure come into being. Benefiting from the interconnected structure of the multi-layer shell, the Fe〈sub〉7〈/sub〉S〈sub〉8〈/sub〉@ Fe〈sub〉5〈/sub〉Ni〈sub〉4〈/sub〉S〈sub〉8〈/sub〉 nanosflower displays high specific capacitance of 670.4C g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉, excellent rate capability of 79.2% (531.0C g〈sup〉−1〈/sup〉 at 20 A g〈sup〉−1〈/sup〉), and longer cycling stability of 92.1% retained capacitance after 5000 cycles. Furthermore, the assembled hybrid supercapacitor demonstrates high energy density of 49.9 Wh kg〈sup〉−1〈/sup〉 at power density of 770.0 W kg〈sup〉−1〈/sup〉. Our results provide a new strategy to design metal sulfides with special structure for application to asymmetrical supercapacitor cathode material.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A three-phase core/shell flower-like Fe〈sub〉7〈/sub〉S〈sub〉8〈/sub〉@Fe〈sub〉5〈/sub〉Ni〈sub〉4〈/sub〉S〈sub〉8〈/sub〉 is successfully constructed by one step alcohothermal technique using a mixture solvent of glycerol, diethylene glycol and ethylenediamine. The as-obtained composites become a promising electrode material for the next generation energy storage devices with high specific capacitance (670.4C g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉), excellent energy density (49.9 Wh kg〈sup〉−1〈/sup〉 at power density of 770.0 W kg〈sup〉−1〈/sup〉), as well as good long-term cycling stability (almost 88.9% retention after 10,000 cycles).〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312906-ga1.jpg" width="496" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Min Sun, Wei Hu, Tianqiong Cheng, Yusheng Chen, Peng Yao, Ming Zhao, Shandong Yuan, Yaoqiang Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A series of Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 samples were prepared by conventional coprecipitation, wet impregnation method and novel deposition precipitation, after the corresponding Pd-only close coupled catalysts were obtained by incipient wet impregnation. Differences in surface properties and catalytic performance were investigated systematically by a wealth of characterizations. XPS, H〈sub〉2〈/sub〉-TPR and CO chemisorption revealed that the different preparation methods of Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 led to different intensity of interaction between PdO species and support, thus forming different palladium dispersions. BET, XRD and activity evaluation indicated the catalyst obtained by novel deposition precipitation presented superior textural properties, catalytic performance and thermal stability, due to the strongest interaction proved by H〈sub〉2〈/sub〉-TPR, XPS and CO chemisorption, which could retard the sintering of noble metal during the aging process. HRTEM images indicate for the catalysts, PdO species are mainly dispersed and stabilized on the ceria resulting from the lower redox potential of Pd〈sup〉2+〈/sup〉/Pd〈sup〉0〈/sup〉 (0.95 V) than that of Ce〈sup〉4+〈/sup〉/Ce〈sup〉3+〈/sup〉 (1.72 V). Consequently, it owned higher surface PdO content and dispersion than the catalysts prepared by coprecipitation and impregnation method, presenting its higher catalytic properties.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The different preparation methods about ceria-zirconia modified alumina influence palladium dispersion by the interaction, which is main factor in influencing close coupled catalytic activity. The catalyst obtained by deposition precipitation owns higher surface palladium species than the sample synthesized by coprecipitation method, and higher palladium dispersion than the catalyst prepared by wet-impregnation method. A simple process is described as is shown above, and specific process is illustrated in my article.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329696-ga1.jpg" width="198" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Ngoc-Hanh Cao-Luu, Quoc-Thai Pham, Zong-Han Yao, Fu-Ming Wang, Chorng-Shyan Chern〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Hypothesis〈/h6〉 〈p〉How to encapsulate poly(N-isopropylacrylamide) (PNIPAM) mesoglobule cores by silica shells greatly affects the resultant nanoparticle structures. Incorporation of acrylamide (AM) unit into PNIPAM in combination with 3-glycidyloxypropyltrimethoxysilane (GLYMO, as a coupling agent) effectively induces nucleation and growth of silica on PNIPAM core surfaces, where the –NH〈sub〉2〈/sub〉 of acrylamide reacts with the epoxide of GLYMO while GLYMO further participates in subsequent sol-gel reaction of tetraethyl orthosilicate (TEOS), thereby leading to desirable particle morphology.〈/p〉 〈/div〉 〈div〉 〈h6〉Experiments〈/h6〉 〈p〉PNIPAM-based core–silica shell nanoparticles were prepared by sol〈em〉-〈/em〉gel reaction of TEOS and GLYMO in the presence of polymeric core particles. The major parameters investigated in a systematic fashion include acrylamide concentration and weight ratio of polymer:GLYMO:TEOS. GPC, DLS, DSC, FE-SEM, TEM, FTIR and TGA were then used to characterize polymeric cores and hybrid nanoparticles.〈/p〉 〈/div〉 〈div〉 〈h6〉Findings〈/h6〉 〈p〉The particle morphology was governed primarily by the acrylamide content and the weight ratio of PNIPAM/AM:GLYMO:TEOS, and desirable hybrid nanoparticles with narrow particle size distribution were achieved. The LCST of PNIPAM-based mesoglobules increases with increasing acrylamide content. Encapsulation of PNIPAM-based mesoglobules with silica also reduces their thermo-sensitivity. This is the first report of developing a novel approach to prepare PNIPAM-based mesoglobule core–silica shell nanoparticles with controllable particle morphologies.〈/p〉 〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312888-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Magdalena Broda, Carmen-Mihaela Popescu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wood has been extensively used as a material for different applications over the years, therefore the understanding of different degradation processes in various environments is of great importance. In this study, the infrared spectroscopy, X-ray diffraction and chemometric methods were used to evaluate and compare the structure of archaeological and artificially degraded oak wood. The results clearly show that modifications in the structure of archaeological wood are related to the position of the material in the log (sapwood and heartwood), thus the extent of wood degradation. To identify the possible factors influencing these effects, the control wood samples were exposed to artificial white rot biodegradation with 〈em〉Coriolus〈/em〉 (〈em〉Trametes〈/em〉) 〈em〉versicolor〈/em〉 and to alkali treatment (with NaOH solution). Due to the structural similarities between biodegraded wood and control or archaeological samples, this type of decay is likely to occur during natural ageing along with degradation produced by other environmental factors. Further, no real similarity was identified between the alkali treated wood and archaeological samples, indicating that such degradation does not affect wood under natural conditions.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309909-ga1.jpg" width="295" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Yi Zhong, Zetian He, Daimei Chen, Ding Hao, Weichang Hao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The fluorine substitution on Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 (F-Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉) can be easily synthesized by a hydrothermal method. Based on the XRD result, it could be speculated that fluorine ion can substitute oxygen ion in the crystal lattice of Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉. The photodegradation activity of F-Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 almost is 1.9 times as high as the single Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 for degradation of RhB and 1.7 times for decomposition of 2, 4-CDP under the visible light. The enhanced catalytic activity of F-Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 should be attributed to the wider band gap, the more positive VB potential and the higher concentration of OH〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉 radicals due to the F doping. Additionally, F doping formed the donor state below the Fermi energy, which can trap the electrons and increase the efficiency of charge separation remarkably.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329647-ga1.jpg" width="387" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Hamad Ullah, Yu Qu, Tiankun Wang, Yongkai Wang, Zhimin Jing, Zhongyue Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Artificially engineered chiral plasmonic nanostructures (CPNs) have attracted considerable attention and have been widely studied in the recent decades because of their distinguishing optical properties. Researchers have focused on noble metal nanostructures, because of their strong chiroptical response in visible and near-infrared regions. In this study, a system of a nanorod coupled with a nanosurface, which were both made of silver, was proposed. Glancing angle deposition (GLAD) method was used to fabricate CPNs. The fabricated CPNs generated a strong circular dichroism (CD) signal under visible and near-infrared light illumination. A high peak was observed at approximately 600 nm, and an increasing trend of the CD intensity with a redshift was confirmed when the area of the nanosurface was increased. The generated CD could be tuned easily by changing the area of the nanosurface with an active control of the vapor deposition angle (glancing angle of the substrate) in the GLAD method.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329775-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Lida Chen, Enzhou Liu, Feng Teng, Tianxi Zhang, Juan Feng, Yumeng Kou, Qian Sun, Jun Fan, Xiaoyun Hu, Hui Miao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two-dimensional (2D) metal dichalcogenides have attracted considerable attention in photoelectrochemical (PEC) water splitting because of their particular layer structure and strong interaction with light. Herein, in this article, we report a facile chemical vapor deposition (CVD) method, via low boiling point SnCl〈sub〉4〈/sub〉·5H〈sub〉2〈/sub〉O and S powders as precursors. Light trapping nanosheets arrays SnS〈sub〉2〈/sub〉 (SnS〈sub〉2〈/sub〉⊥FTO) have been deposited on conductive substrate. By optimizing the preparation conditions, included deposition temperature, flow rate of carrier gas and the distance between the Sn source and growth substrate. Moreover, the key factors to affect the growth of SnS〈sub〉2〈/sub〉 in CVD process have been investigated in detail. In PEC measurements, the as-synthesized thin film of 450 °C, 50 sccm, 11 cm shows the highest photocurrent density of up to 3.68 mA cm〈sup〉−2〈/sup〉 at 0.5 V 〈em〉vs.〈/em〉 SCE under the sunlight and high IPCE of up to 33.11% at 365 nm. The values much higher than conventional photoelectrode by spin-coating (SnS〈sub〉2〈/sub〉//FTO), which achieved efficient photoelectrochemical water splitting under the sunlight.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Patryk Wąsik, Annela M. Seddon, Hua Wu, Wuge H. Briscoe〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a box counting fractal dimension (FD) analysis of the dendritic patterns obtained under conditions far from equilibrium 〈em〉via〈/em〉 rapid evaporation of a sessile drop containing 〈em〉reactive〈/em〉 ZnO nanoparticles. These dendrites were manifestations of solidified Bénard-Marangoni (BM) instability convection cells, and we previously noted that their complex hierarchical morphologies were superficially analogous to the foliage of red algae, Spanish dagger, or spider plant. The fractal dimension of the Bénard-Marangoni dendrites was found to vary in the range of 1.77–1.89 and also depend on the size of the Bénard-Marangoni cells. These fractal dimension results were correlated with the morphological details of the Bénard-Marangoni cells and ZnO particle characteristics, providing a quantitative description of such complex surface patterns emerging from the dynamic process of the Bénard-Marangoni instability.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312773-ga1.jpg" width="498" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Bin Fang, Xingchang Lu, Junyi Hu, Geng Zhang, Xinsheng Zheng, Limin He, Jianbo Cao, Jiangjiang Gu, Feifei Cao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Emerging carbon dots (CDs) are widely used as fluorescent probes in biological and environmental fields, nevertheless, the control of CDs based on different detection mechanisms is rarely reported. In this paper, green luminescent CDs (G-CDs) were prepared by a facile hydrothermal treatment of benzoxazine monomers (BZM). The obtained G-CDs showed pH dependent photoluminescence, which could be designed as fluorescence turn-on and turn-off sensors. The G-CDs exhibited weak photoluminescence at pH = 7.0 and could be turned on by Zn(II) selectively with the limitation of 0.32 μM in the concentration range from 1 to 100 μM. When pH = 10.0, Cr(VI) could quench the strong fluorescence of G-CDs efficiently, and the limit of detection was 0.99 μM with a linear range of 1–50 μM. Furthermore, the fluorescence turn-on and turn-off performance of G-CDs was attributed to the intramolecular charge transfer (ICT) of Zn(II) and the inner filter effect (IFE) of Cr(VI), respectively. The excellent probes were successfully applied for the detection of Zn(II) in biological system and Cr(VI) in environment.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312839-ga1.jpg" width="463" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Prathap Reddy Patlolla, Nakshi Desai, Sharad Gupta, Bhaskar Datta〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interaction of fluorescent dyes with serum proteins has garnered significant interest owing to potential for non-covalent labeling and imaging applications. In this work, dimeric benzothiazole-based trimethine cyanine dyes are synthesized and their interaction with bovine serum albumin studied. The dimeric cyanine dyes mainly exist as H-dimers and H-aggregates in aqueous solution. A combination of absorbance, fluorescence, circular dichroism spectroscopy and atomic force and fluorescence microscopy indicate the formation of dye-BSA complexes. Binding of one of the dimeric dyes on BSA with a K〈sub〉a〈/sub〉 of 1.49 × 10〈sup〉5〈/sup〉 M〈sup〉−1〈/sup〉 results in disruption of dye self-aggregates and unfolding of the dyes into the monomeric or open conformation. Fluorescence enhancement experienced by the dimeric dyes upon interaction with BSA is superior to that registered by Thioflavin T. Surfactant SDS has been used to further tune the self-aggregation of the dimeric dye resulting in a 200-fold fluorescence enhancement in presence of BSA. Interaction of a dimeric dye with BSA under conditions favoring protein aggregation is found to result in faster dye binding and the resulting fluorescence enhancement is easily visualized by fluorescence microscopy. The interaction of a dimeric cyanine dye aggregate with BSA is promising for non-covalent labeling applications in sharp contrast to the monomeric dye counterpart.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309818-ga1.jpg" width="322" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Huan Zong, Xijiao Mu, Jiangcai Wang, Huifang Zhao, Ying Shi, Mengtao Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, we report time resolved fluorescence resonance energy transfer (FRET) using femtosecond ultrafast transient absorption spectroscopy. The lifetimes of FRET are strongly dependent on the molecular concentration and ratio of donor and acceptor. Also, in the FRET, photoinduced intermolecular charge transfer (PICT) is also investigated theoretically. The driving force for PICT in FRET system equals the reorganization energy, which gives barrier-less charge transfer according to Marcus theory. The rates of PICT in the FRET system can be estimated with our simplified Marcus equation. Our results of PICT in FRET system provide a new efficient way for the charge transfer in donor-acceptor system.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309855-ga1.jpg" width="296" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Kai Zhang, Lei Cai, Jianzhong Fan, Yuchen Zhang, Lili Lin, Chuan-Kui Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, thermally activated delayed fluorescence (TADF) molecules have attracted great attention since nearly 100% exciton usage efficiency was obtained in TADF molecules. Most TADF molecules used in organic light-emitting diodes are in aggregation state, so it is necessary to make out the intermolecular interaction on their photophysical properties. In this work, the excited-state properties of the molecule AI-Cz in solid phase are theoretically studied by the combined quantum mechanics and molecular mechanics (QM/MM) method. Our results show that geometry changes between the ground state (S〈sub〉0〈/sub〉) and the first singlet excited state (S〈sub〉1〈/sub〉) are limited due to the intermolecular π-π and CH-π interactions. The energy gap between S〈sub〉1〈/sub〉 and the first triplet excited state is broadened and the transition properties of excited states are changed. Moreover, the Huang-Rhys factors and the reorganization energy between S〈sub〉0〈/sub〉 and S〈sub〉1〈/sub〉 are decreased in solid phase, because the vibration modes and rotations are hindered by intermolecular interaction. The non-radiative rate has a large decrease in solid phase which improves the light-emitting performance of the molecule. Our calculation provides a reasonable explanation for experimental measurements and highlights the effect of intermolecular interaction on excited-states properties of TADF molecules.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309867-ga1.jpg" width="499" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Tinggui Chen, Xueying Pei, Yongkang Yue, Fangjun Huo, Caixia Yin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cysteine (Cys) is not only the central matter of sulfur metabolism in cells but also the only amino acid with reduced thiol group in 20 kinds of natural amino acids. In animal cells, Cys is taking part in many important and essential biological functions including protein synthesis, detoxification and metabolism. The development and application of fluorescent probes for the detection of Cys have attracted more and more attention and interest. Herein, we report a new fluorescent probe 〈strong〉NFA〈/strong〉 that utilized naphthyl carboxy fluorescein as fluorophore and acryloyl group as reaction site for Cys specific detection. The probe essentially has weak fluorescence. Cys addition to 〈strong〉NFA〈/strong〉 containing system induced distinct enhanced fluorescence emission which was attributed to the nucleophilic reaction of cysteine and acryloyl to release the fluorophore. The signal fluorescent response detection system allows 〈strong〉NFA〈/strong〉 to be a reliable tool for Cys detection with low detection limit (0.58 μM). And 〈strong〉NFA〈/strong〉 has been successfully applied for Cys imaging specifically in live Hela cells, which promotes the probe as a potential tool to understand the pathology of Cys related diseases.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S138614251830982X-ga1.jpg" width="339" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/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: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Linan Wang, Shuxian Zhuang, Liu Wang, Na Wang, Hengliang Mo, Yang Tang, Yongmei Chen, Yanzhi Sun, Pingyu Wan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Co(OH)〈sub〉2〈/sub〉 nanoflakes integrating with Cu nanoparticles were deposited on nickel foam (CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉) by a green and facile one-step deposition method and used for non-enzymatic glucose sensors. The CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 composite was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. Electrochemical oxidation of glucose on the CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 composite was investigated by chronoamperometry and cyclic voltammetry. The prepared CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 electrode shows not only an extremely high sensitivity of 42.7 mA mM〈sup〉−1〈/sup〉 cm〈sup〉−2〈/sup〉 in the concentration range from 1 to 250 μM for glucose detection but also an obvious current response to glucose at a level of 1 μM with a low detection limit of 73 nM (S/N = 3). Moreover, the glucose sensor based on CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 also exhibits high recovery ratio toward real sample analysis. This work indicates that the fast electron transfer, large surface area, and highly effective active sites based on the hierarchical structure of ultra-thin and open-interlaced Co(OH)〈sub〉2〈/sub〉Nfs interspersed by CuNps contribute to the excellent performance of CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 electrodes. The proposed one-step preparation of hierarchical nanostructure of CuNps and Co(OH)〈sub〉2〈/sub〉Nfs provides a promising and efficient strategy in the development of outstanding non-enzymatic glucose biosensors.〈/p〉〈/div〉 〈/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: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering〈/p〉 〈p〉Author(s): J. Machaček, Th. Triantafyllidis, P. Staubach〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Earthquake stability assessment of large opencast mine slopes are complex and non-linear problems, often addressed using pseudo-static approaches neglecting material-induced failures and the role of pore-fluids. In this study, a numerical approach is used to understand the dynamic response of saturated and partially saturated soils. For this purpose user-defined elements have been implemented in 〈em〉Abaqus/Standard〈/em〉 including user-defined material models. The governing equations involving coupled fluid flow and finite deformation processes in partially saturated soils are derived within the framework of the 〈em〉Theory of Porous Media〈/em〉. The stress-strain behavior of granular soils is represented by a 〈em〉hypoplastic〈/em〉 constitutive model and for clayey soils the 〈em〉ISA-Clay〈/em〉 model is used. The saturation-suction behavior is modeled using the 〈em〉van Genuchten〈/em〉 model. To account for the large scale of the finite element model, a scaling procedure of the system of equations is proposed to purge the influence of initial stress. The performance of the user-defined elements is tested by back analysis of a centrifuge test available in the literature. Finally, large-scale fully coupled finite element simulations are performed to study the response of a flooded opencast mine under earthquake loading. The paper illustrates the importance of accounting the pore-fluids as independent phases in the context of seismic analysis of slopes and the influence of simplifications on which the calculation is based are highlighted. The simulations show strong wave diffraction effects for inhomogeneous dump structures, resulting in smaller displacements in near-surface areas of the slope. Further it was found that large areas of the dump show a temporary decrease of effective stress. The initial strong differences in stiffness between the different materials may decrease with time after several seismic events due stress redistributions caused by earthquakes.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Qiong Sun, Songhao Wu, Di You, Tao Zang, Lifeng Dong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic fuel cell (PFC) is a newly developed cell device that can effectively convert chemical energy resulted from photocatalytic process into electrical energy. In this research, a novel composite functional dual-chambered photocatalytic fuel cell is designed and optimized. In the cathode chamber, the Fenton-like reaction is introduced to produce strong oxidizing OH〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉 radicals, which thereby enhances the advanced oxidation of wastewater and is much faster than the anode reaction. Meanwhile, photo-induced charge transfer as well as electronic generation ability can be further improved compared with the system only with O〈sub〉2〈/sub〉 pumped in. With the help of this special PFC device, the electrode reactions can occur in two chambers independently, thus different types of organic substances can be degraded, accompanying with the generation of electrical energy simultaneously. According to the degradation of various dyes, it is found that the anode reaction is more suitable for the degradation of cationic dye rather than anionic dye, and just reverses for the cathode reaction. Among four selective types of dyes, the PFC shows the best purification effect to X3B, while the highest enhancement of electric output is found when methylene blue (MB) is employed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329672-ga1.jpg" width="312" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Huihui Sun, Katarzyna Zielinska, Marina Resmini, Ali Zarbakhsh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In dermal drug delivery, the influence of the chemical structure of the carriers on their penetration mechanisms is not yet fully understood. This is a key requirement in order to design highly efficient delivery systems. In this study, neutron reflectivity is used to provide insights into the interactions between thermoresponsive 〈em〉N〈/em〉-isopropylacrylamide based nanogels, cross-linked with 10%, 20% and 30% 〈em〉N,N'〈/em〉-methylenebisacrylamide, and skin lipid multi-bilayers models. Ceramide lipid multi-bilayers and ceramide/cholesterol/behenic acid mixed lipid multi-bilayers were used for this work. The results indicated that in both multi-bilayers the lipids were depleted by the nanogels mainly through hydrophobic interactions. The ability of nanogels to associate with skin lipids to form water-dispersible complexes was found to be a function of the percentage cross-linker. An enhanced depletion of lipids was further observed in the presence of benzyl alcohol, a well-known skin penetration enhancer.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312840-ga1.jpg" width="294" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Zexing Wu, Min Song, Zijin Zhang, Jie Wang, Xien Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Investigation of non-precious, highly-active and durable catalysts is an essential criteria for the development of electrocatalytic hydrogen evolution reaction (HER). In this work, reduced graphene oxide coupled with molybdenum phosphide (MoP-RGO) is prepared through a facile and scalable one-step strategy. Three strategies are developed to tune the electrocatalytic performance of MoP-RGO including optimize the pyrolysis temperature, add NaCl template and introduction of sulfur atoms. After the optimization, the overpotentials at 10 mA cm〈sup〉−2〈/sup〉 reduced from 238 to 152 mV (alkaline electrolyte) and 232 to 144 mV (acid medium), respectively. This work mainly focus on exploiting various strategies to tune the electrocatalytic performance of non-precious catalysts for HER which can provide multiple avenues to develop efficient electrocatalysts.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Pyrolysis temperature, NaCl template and sulfur atom are used to tune the electrocatalytic performance of MoP-RGO. After the optimized process, the overpotentials needed to deliver 10 mA cm〈sup〉−2〈/sup〉 reduced from 238 to 152 mV (alkaline electrolyte) and 232 to 144 mV (acid medium), respectively.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312657-ga1.jpg" width="353" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Prakhar Sengar, Karelid Garcia-Tapia, Kanchan Chauhan, Akhil Jain, Karla Juarez-Moreno, Hugo A. Borbón-Nuñez, Hugo Tiznado, Oscar E. Contreras, Gustavo A. Hirata〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The current photodynamic therapy (PDT) is majorly hindered by the shallow penetration depth and oxygen dependency, limiting its application to deep-seated solid hypoxic tumors. Thus, it is meaningful to develop efficient X-ray mediated PDT system capable of generating reactive oxygen species (ROS) under both the normoxic and hypoxic conditions. Herein, we report the synthesis and characterization of nanocomposite, YAG:Pr@ZnO@PpIX with an amalgamation of UV-emitting Y〈sub〉2.99〈/sub〉Pr〈sub〉0.01〈/sub〉Al〈sub〉5〈/sub〉O〈sub〉12〈/sub〉 (YAG:Pr) nanoscintillator, and zinc oxide (ZnO) and protoporphyrin IX (PpIX) as photosensitizers. YAG:Pr surface was coated with a ZnO layer (∼10 nm) by atomic layer deposition, and then PpIX was covalently conjugated via a linker to give YAG:Pr@ZnO@PpIX. The photo- and cathodoluminescence analyses gave the evidences of efficient energy transfer from YAG:Pr to ZnO at ∼320 nm, and YAG:Pr@ZnO to PpIX at Soret region (350–450 nm). The nanohybrid was able to produce both, Type I and Type II ROS upon direct and indirect photoactivation with UV〈sub〉365nm〈/sub〉 and UV〈sub〉290nm〈/sub〉, respectively. In vitro cytotoxicity of non-activated YAG:Pr@ZnO@PpIX in mouse melanoma cells revealed low toxicity, which significantly enhanced upon photoactivation with UV〈sub〉365nm〈/sub〉 indicating the photokilling property of the nanohybrid. Overall, our preliminary studies successfully demonstrate the potential of YAG:Pr@ZnO@PpIX to overcome the limited penetration and oxygen-dependency of traditional PDT.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021979718312876-ga1.jpg" width="287" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Beibei Liu, Shuo Wang, Zirui Ma, Jiawang Ma, Ruixin Ma, Chengyan Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Perovskite solar cell has gained wide attention due to its excellent photoelectric performance and economical fabrication process, with high-efficiency perovskite solar cell could be achieved by optimizing film morphology. In this work, a kind of Lewis-bases, urea(U), was used as a novel additive in synergy with DMSO to regulate the crystallization processes. Adding slight amount of DMSO can obviously improve the reproducibility of device and optimize the spin-coating process. The mechanism of the action can be explained by infrared spectroscopy. Under the coordination of the lead ion that could accept electron pairs and the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O bond in urea, introduction of urea in perovskite precursor solution to form MAI·PbI〈sub〉2〈/sub〉·DMSO·urea complex could significantly improve the photoelectric properties of the perovskite films. It formed a smooth and large grain-size perovskite film with no visible pinhole or crack found. Finally, the device fabricated with the incorporation of 50% urea presented a high performance with a PCE of 17.82%.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): İkram Orak, Hamit Eren, Necmi Bıyıklı, Aykutlu Dâna〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a methodology for producing highly controlled and uniformly dispersed metal nanoparticles were developed by atomic layer deposition (ALD) technique. All-ALD grown thin film flash memory (TFFM) cells and their applications were demonstrated with ultra-small platinum nanoparticles (Pt-NPs) as charge trapping layer and control tunnel oxide layer. The ultra-small Pt-NPs possessed sizes ranging from 2.3 to 2.6 nm and particle densities of about 2.5 × 10〈sup〉13〈/sup〉 cm〈sup〉–b〈/sup〉. The effect of Pt-NPs embedded on the storage layer for charging was investigated. The charging effect of ultra-small Pt-NPs the storage layer was observed using the electrical characteristics of TFFM. The Pt-NPs were observed by a high-resolution scanning electron microscopy (HR-SEM). The memory effect was manifested by hysteresis in the I〈sub〉DS〈/sub〉-V〈sub〉DS〈/sub〉 and I〈sub〉DS〈/sub〉-V〈sub〉GS〈/sub〉 curves. The charge storage capacity of the TFFM cells demonstrated that ALD-grown Pt-NPs in conjunction with ZnO layer can be considered as a promising candidate for memory devices. Moreover, ZnO TFFM showed a I〈sub〉ON〈/sub〉/I〈sub〉OFF〈/sub〉 ratio of up to 52 orders of magnitude and its threshold voltage (V〈sub〉th〈/sub〉) was approximately −4.1 V using I〈sub〉ds〈/sub〉〈sup〉−a/b〈/sup〉 – V〈sub〉gs〈/sub〉 curve. Fabricated TFFMs exhibited clear pinch-off and show n-type field effect transistor (FET) behavior. The role of atomic-scale controlled Pt-NPs for improvement of devices were also discussed and they indicated that ALD-grown Pt-NPs can be utilized in nanoscale electronic devices as alternative quantum dot structures.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329945-ga1.jpg" width="345" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): A. Ladrón-de-Guevara, A. Boscá, J. Pedrós, E. Climent-Pascual, A. de Andrés, F. Calle, J. Martínez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report on the precise fabrication of low-cost high-performance electrochemical supercapacitors using reduced graphene oxide/polyaniline nanofiber composite electrodes. An infrared laser has been used to reduce the graphene oxide, converting the initial graphene oxide compact layer into a three dimensional open network of exfoliated graphene flakes. This highly conducting porous structure is very well suited for electrodepositing pseudocapacitive materials owing to its large surface area. Polyaniline nanofibers have been controllably electrodeposited on the graphene flake network, not only extending further the electrode surface area and providing it with a strong pseudocapacitance but also preventing the restacking of the graphene sheets during the subsequent device processing and charge-discharge cycling. The composite electrode presents a specific capacitance of 442 F g〈sup〉−1〈/sup〉, as compared to 81 F g〈sup〉−1〈/sup〉 for the bare reduced graphene oxide counterpart, and a capacitance retention of 84% over 2000 cycles.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329738-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Catalysis Today〈/p〉 〈p〉Author(s): Pierre Pichat〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Studies of the adsorption and reactions of appropriate molecules are a valuable means to probe active surfaces. This overview deals with the use of nitrogen monoxide – a molecule that has less been utilized than some others as a surface probe – to investigate TiO〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉-containing materials, with or without photo-excitation. It shows that diverse information can be derived from: (1) the infrared spectra of adsorbed NO; (2) the isotopic exchange of N〈sup〉18〈/sup〉O; (3) the formation of N〈sub〉2〈/sub〉O and N〈sub〉2〈/sub〉; (4) the use of NO (or N〈sup〉18〈/sup〉O) in oxidation reactions in place of O〈sub〉2〈/sub〉; and (5) the evaluation of the electron transfer to NO through density functional theory calculations, ultraviolet photoemission spectroscopy, and photoconductance measurements. Valuable knowledge may thus be potentially acquired on: the accessibility and reactivity of surface OH groups, the lability of surface O atoms, the self-cleaning efficacy, the environment and dispersion of TiO〈sub〉2〈/sub〉 in composite materials, the existence of bandgap electronic states, and the electron transfer capacity, depending on the investigation technique employed, the conditions and the type of TiO〈sub〉2〈/sub〉 sample.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0920586118311921-ga1.jpg" width="348" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Sami Rtimi, Victor Nadtochenko, Inessa Khmel, Stéphanos Konstantinidis, Nikolay Britun, John Kiwi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cu-polyester (Cu-PES) was sputtered by high power impulse magnetron sputtering (HIPIMS) and by low energy direct current magnetron sputtering (DCMS). The total amount and distribution of the Ar〈sup〉+〈/sup〉, Cu〈sup〉+〈/sup〉 and Cu〈sup〉2+〈/sup〉 ions were determined as well as the bacterial inactivation kinetics mediated by DCMS and HIPIMS samples. The separation of extracellular and intracellular processes leading to bacterial inactivation was assessed on normal and genetically modified 〈em〉E. coli〈/em〉.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329878-ga1.jpg" width="250" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 30 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Catalysis Today〈/p〉 〈p〉Author(s): G. Bonura, A.A. Khassin, T.M. Yurieva, C. Cannilla, F. Frusteri, L. Frusteri〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A series of coprecipitated binary Cu-ZrO〈sub〉2〈/sub〉 catalysts was found to show an interesting activity–selectivity pattern during methanol synthesis from catalytic hydrogenation of carbon oxides (〈em〉P〈/em〉〈sub〉R〈/sub〉, 20–30 atm; 〈em〉T〈/em〉〈sub〉R〈/sub〉, 200–240 °C). The effects of various pre–treatments as well as the copper/zirconia ratio on the structural and chemical properties of these samples were examined. The isoconversional Ozawa-Flynn-Wall method was applied to study the reduction behaviour, while the best fit modelling was used to establish the plausible mechanism of copper reduction. The extent of methanol formation rate was found to be dependent on the structure formed upon catalyst reduction, both in CO and in CO〈sub〉2〈/sub〉 hydrogenation conditions. The pre–calcination of the sample at a temperature as high as 650 °C negatively affected the methanol formation rate under CO hydrogenation conditions, while under the same activation treatment an increased specific activity was observed in CO〈sub〉2〈/sub〉 hydrogenation conditions, although with a minor methanol selectivity, since the rate of the WGS reaction was stronger enhanced. The incorporation of Zn into the catalyst formulation resulted in a visible increasing of the methanol formation rate, owing to the formation of a copper–zinc mixed oxide during calcination, which leads to higher metal dispersion also depressing the methane formation rate.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0920586118307028-ga1.jpg" width="286" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 210〈/p〉 〈p〉Author(s): Chinduluri Sravani, Mohsin Y. Lone, Prakash C. Jha, K.I. Sathiyanarayanan, Akella Sivaramakrishna〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new series of 2‑styryl phenanthro[9,10‑〈em〉d〈/em〉]oxazoles was readily accessible from the condensation reaction of 9,10‑phenanthroquinone with cinnamaldehydes in the presence of lactic acid. All these styryl dyes were isolated in good yields and characterized by various analytical and spectroscopic techniques. One of the dyes containing 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉NO〈sub〉2〈/sub〉 group (〈strong〉3d〈/strong〉) was structurally characterized by single crystal X-ray analysis. These dyes displayed emission in blue to green region with larger Stokes shift values characteristic to the nature of substituents. In addition, positive solvatochromic trend was observed by increasing the solvent polarity suggestive of a more stabilized polar excited state. Moreover, the addition of trifluoroacetic acid leads to a prominent blue-shift in visible and emission color changes owing to the protonation of the nitrogen atom of oxazole moiety. Among the all, the oxazole derivative having 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉NMe〈sub〉2〈/sub〉 group (〈strong〉3b〈/strong〉) exhibits good response to acidic pH in the range of 3.0 to 5.6 with a good linearity upon decreasing the pH from 8.0 to 2.16. The absorption studies were further supported by density functional theory calculations.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309880-ga1.jpg" width="430" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Anxin Jiao, Xuejian Dong, Hua Zhang, Linlin Xu, Yue Tian, Xiangdong Liu, Ming Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ultrasensitive detection of pesticide residues on agricultural products using surface-enhanced Raman spectroscopy (SERS) is of significant interest in food security. Herein, worm-like AuAg nanochains with highly interconnected ultrafine (~6.2 nm) bimetallic particles were developed as an excellent SERS nanosensor via laser-assisted strategy. The SERS detection limit of thiram molecules on apple surfaces is about 10〈sup〉−7〈/sup〉 M (0.03 ppm), which is about 200 times lower than the maximal residue limit (MRL, 7 ppm) in fruit prescribed by the U.S. Environmental Protection Agency (EPA). Importantly, the established excellent linear relationships between the SERS intensities and thiram concentrations can sensitively monitor the slight variation of pesticide residues in agriculture.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309843-ga1.jpg" width="331" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 208〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Manjushree M., Revanasiddappa H.D.〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bupropion hydrochloride (BPH) an antidepressant and widely used to treat addiction of nicotine. The actual protein existing in blood plasma for the vehicle of exogenous and endogenous substances is human serum albumin 〈em〉i〈/em〉.〈em〉e〈/em〉. HSA. The interaction of BPH with HSA was examined by molecular docking, multiple spectroscopy's such as fluorescence (emission, synchronous and three-dimensional), UV–vis (ultraviolet–visible), FT–IR (Fourier transform infrared) and CD (circular dichroism) at physiological pH 7.40 at 286, 296 and 306 K. BPH was particularly bind to HSA through forces called hydrogen bonds and vander Waals at site I (IIA) which was confirmed from negative values of thermodynamics calculated by van't Hoff equation and docking studies in addition to site marker analysis. This interaction was spontaneous and exothermic process. Secondary structure including conformation of HSA changes after interaction with BPH was revealed from CD and FT–IR (Fourier self-deconvolution to curve fitting), UV–vis, 3D and synchronous florescence techniques. Forster's theory (non–radiation energy transfer) was applied to calculate the distance from tryptophan of HSA to BPH. This interaction involves static quenching (Stern–Volmer and Modified Stern–Volmer equations) with larger binding constant values were in the range 10〈sup〉5〈/sup〉 confirming that strong interaction was exists between BPH and HSA. The interference of bio-active Mg〈sup〉2+〈/sup〉, Cu〈sup〉2+〈/sup〉, Zn〈sup〉2+〈/sup〉, Ca〈sup〉2+〈/sup〉 and Fe〈sup〉2+〈/sup〉 metal ions on this interaction was also analysed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309806-ga1.jpg" width="410" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 114〈/p〉 〈p〉Author(s): Yuanzheng Lin, Zhouhong Zong, Shizhu Tian, Jin Lin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Most current baseline correction methods for near-fault ground motion records focus on eliminating and minimizing baseline errors and obtaining true ground motion records that are in accordance with GPS-measured coseismic displacements. Though these methods can recover true ground motions, the single value of ground permanent displacement cannot meet the requirement of seismic response analysis of fault-crossing bridge with the consideration of various levels of relative static displacements. Besides, the corrected final displacements are often too large which will cause an extremely large pseudo-static response and a relatively small dynamic response in bridge structures. To provide across-fault seismic excitations with a reasonable series of final displacements, a new baseline correction scheme based on the target final displacement is proposed in this study, in which an additional offset displacement is introduced based on the Iwan correction scheme. The new baseline correction scheme aims at modifying the pseudo-static displacement of ground motion records to facilitate the agreement between the achieved final displacement and the target final displacement. The correction scheme is then examined in three aspects including time histories, response spectra and bridge responses. The analysis results indicate that sets of the corrected time history records with a large range of final displacements can be well achieved with a minor influence on spectral characteristics. The seismic response analysis of a cable-stayed bridge crossing a dip-slip fault-rupture zone shows that the pseudo-static response can be controlled, meanwhile, the dynamic response remains almost intact by using the new baseline correction scheme. This work can be used as a reference for input excitations of bridge crossing fault-rupture zones.〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 114〈/p〉 〈p〉Author(s): Xinzheng Lu, Lei Zhang, Yao Cui, Yi Li, Lieping Ye〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, seismic resilience has become a research frontier in civil engineering. The self-centering steel frame can effectively control structural damage and reduce structural residual deformation, which ensures rapid repair after an earthquake. Therefore, such a structural system has attracted extensive attention from researchers. One of the important research directions on self-centering steel frames is the development of high-performance energy-dissipating components. A new type of dual-functional replaceable stiffening angle steel (SAS) component is proposed here. It can effectively improve the stiffness and strength of beam-column connections and has sufficient energy-dissipating performance and ductility. Seven different energy-dissipating components were tested, including one angle steel component and six SAS components. The strength and deformation capacity of the components were compared based on monotonic loading tests. The SAS component with the highest out-of-plane stability and sufficient strength and initial stiffness was selected and subsequently tested under hysteretic loading to investigate its energy-dissipating performance. The theoretical analysis methods of the initial stiffness and the yield moment provided by the SAS components were proposed and validated by the finite-element (FE) models calibrated using experimental data.〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 114〈/p〉 〈p〉Author(s): Christos Giarlelis, Jared Keen, Evlalia Lamprinou, Victoria Martin, Gerasimos Poulios〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The recently constructed Stavros Niarchos Foundation Cultural Center (SNFCC), houses the National Opera and the National Library of Greece. In order for the structural design to meet the demanding architectural requirements as well as the high-performance seismic specifications that were set, a seismic isolation system was incorporated. SSI effects due to poor silty sands were an additional challenge. After presenting the design parameters and the choice of seismic isolation type, the paper focuses on the methodology for the seismic design. This, performed in three consecutive stages, includes simple analyses using single-degree of freedom model for initial scheming, dynamic response spectrum analyses for detailed design and non-linear time history analyses using two sets of selected earthquake records, semi-artificial and real ones, for verification of the response. The results demonstrate a good correlation between different analysis techniques and provide a valuable insight into the behaviour of two complex, seismically isolated structures under seismic loads. The problems and solutions resulting from the implementation of the seismic isolation are also briefly presented.〈/p〉〈/div〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 115〈/p〉 〈p〉Author(s): Joonsang Park, Amir M. Kaynia〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we introduce and discuss features and improvements of the well-established stiffness matrix method that is used in simulation of wave propagation in layered media. More specifically, we present stiffness matrices for an acoustic layer and a vertically transverse isotropic (VTI) viscoelastic soil layer. Combining these stiffness matrices enables a straightforward technique for modeling of acousto-elastic wave propagation in layered infinite media. In addition, we propose a technique to simulate discontinuity seismic sources, which was not used earlier in the context of the stiffness matrix method. Finally, we propose a framework to derive a key parameter of the absorbing boundary domain technique Perfectly Matched Layer (PML). Numerical examples are presented in order to help understanding the features and improvements discussed in the study from the fields of geophysics and soil dynamics. It is believed that the features and improvements discussed herein will make the application of the stiffness matrix method even wider and more flexible.〈/p〉〈/div〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 115〈/p〉 〈p〉Author(s): Amin Rahmani, Mahdi Taiebat, W.D. Liam Finn, Carlos E. Ventura〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the current state of practice, static/seismic soil-pile interaction is included in design calculations by a set of one-dimensional (1D) uncoupled springs. The guidelines of American Petroleum Institute (API) are often adopted to develop backbone curves for the lateral springs. The purpose of the paper is to assess the reliability of this practice. Twenty-seven static field and laboratory tests, and two dynamic centrifuge tests are simulated to evaluate the performance of the springs. More detailed elaboration on the performance of the springs is provided by simulation of one of the static tests and both of the dynamic tests using also three-dimensional (3D) continuum approach. The evaluation results indicate that API springs do not capture the major mechanisms involved in soil-pile interaction, and this results in erroneous estimation of pile deflections and bending moments. It is shown that the observed errors stem not only from the insufficient characterization of the spring properties (API backbone curves), but also from the inadequate simulation method in which three-dimensional continuum configuration of the supporting soil is represented by a 1D uncoupled spring.〈/p〉〈/div〉

Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 115〈/p〉 〈p〉Author(s): Sajad Veismoradi, Amirhossein Cheraghi, Ehsan Darvishan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Buckling-Restrained Braced Frames (BRBFs) are among the common seismic resistant systems with many beneficial characteristics such as stable cyclic behavior and high energy dissipation. However, recent studies have shown that BRBFs are susceptible to residual deformations during earthquakes which makes them vulnerable to aftershock events. The aim of the current study is to investigate the aftershock collapse capacity of BRBFs. In the first part of the paper, simplified procedures including IDA and collapse fragility analyses are carried out to gain more insight regarding the residual drift and collapse capacity of the intact frames. Then, aftershock fragility assessment is conducted for several damage states, to highlight the influence of post-mainshock residual drifts on the collapse of the structures. As for the second part, a detailed probabilistic framework is introduced and utilized to include the effects of upcoming aftershocks on the annual collapse probability of the structures. Results show that aftershock can highly intensify the structural response especially when the structure tolerates large residual drifts during the mainshock.〈/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. 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: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering〈/p〉 〈p〉Author(s): Montaser Bakroon, Reza Daryaei, Daniel Aubram, Frank Rackwitz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The buckling of steel pipe piles during installation is numerically studied. Generally, numerical simulation of installation processes is challenging due to large soil deformations. However, by using advanced numerical approaches like Multi-Material Arbitrary Lagrangian-Eulerian (MMALE), such difficulties are mitigated. The Mohr-Coulomb and an elastic-perfectly plastic material model is used for the soil and pile respectively. The pile buckling behavior is verified using analytical solutions. Furthermore, the model is validated by an experiment where a pipe pile is driven into sand using vibratory loading. Several case scenarios, including the effects of heterogeneity in the soil and three imperfection modes (ovality, out-of-straightness, flatness) on the pile buckling are investigated. The numerical model agrees well with the experimental measurements. As a conclusion, when buckling starts, the penetration rate of the pile decreases compared to the non-buckled pile since less energy is dedicated to pile penetration given that it is spent mainly on buckling.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Zheng-Wei Wu, Ming-Hung Chiang, Chien-Liang Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, a facile co-surfactant method has been reported for the synthesis of core-shell Pd/Pt saw-toothed nanocubes (Pd/Pt STNCs). In this method, saw-toothed morphologies increase with decreasing ratio (R) of the concentration of cetyltrimethylammonium bromide to cetyltrimethylammonium chloride in the synthesis solution. High-resolution transmission electron microscopy (HR-TEM) images reveal that the Pd/Pt STNC prepared using R = 4 (Pd/Pt STNC〈sub〉R=4〈/sub〉) has (3 1 0) and (4 1 0) facets on its edge, whereas the Pd/Pt STNCs prepared using R = 1 (Pd/Pt STNC〈sub〉R=1〈/sub〉) and 0.25 (Pd/Pt STNC〈sub〉R=0.25〈/sub〉) have (3 1 1) high-index facets. Furthermore, the comparison based on electrochemical surface area (ESA) shows that carbon-supported Pd/Pt STNC〈sub〉R=4〈/sub〉 used for catalysing acidic oxygen reduction exhibits a kinetic current of 0.44 mA at 0.9 V (vs. RHE), which is 1.4-times greater than that obtained for commercial Pt/C (0.31 mA). The higher activity could be caused by enriched electrons on the Pt outershell with less adsorbed Cl〈sup〉−〈/sup〉 ions, as confirmed by the X-ray photoelectron analyses. Accelerated durability test results show that the Pd/Pt STNC〈sub〉R=4〈/sub〉 catalyst is more stable than Pt/C.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218330058-ga1.jpg" width="296" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Colloid and Interface Science, Volume 536〈/p〉 〈p〉Author(s): Xueyi Guo, Weijia Wang, Xiuhong Yuan, Ying Yang, Qinghua Tian, Yang Xiang, Yan Sun, Zhiming Bai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Magnetic nano capture agent (MNCA)-based magnetic separation is considered as a promising approach to rapidly isolate heavy metals from blood. Limited removal efficiency and potential biosafety risks are the major challenges for the clinical use of MNCA-based magnetic separation. Here, we report a highly-efficient MNCA-based magnetic separation of heavy metals from blood in continuous multi-stage adsorption mode. The interactions between MNCA and blood components (〈em〉e.g.〈/em〉 blood cells and plasma proteins) and the MNCA-induced cellular immune responses are studied in detail. The distribution and redistribution of heavy metals in blood are quantitatively analyzed. It demonstrates that concentration dependent redistribution can increase the contact between heavy metals and MNCA, leading to improvement on heavy metal removal efficiency. The removal performance is tested in batch mode and in continuous mode. Results show that 97.97% of Pb and 96.53% of Cd are removed from blood in 120 min using continuous multi-stage adsorption mode, and the residual concentrations of Pb and Cd in blood decrease from 400 μg L〈sup〉−1〈/sup〉 to 8.11 μg L〈sup〉−1〈/sup〉 and 13.84 μg L〈sup〉−1〈/sup〉, respectively. This study paves an effective way for heavy metal intoxication therapy by MNCA-based magnetic separation.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S002197971831292X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/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): D.M. Kasparek, B.S. McDonald, A.J. Gilbert, R.S. Wittman〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The International Atomic Energy Agency (IAEA) is responsible for verifying the mass of elemental uranium in various forms (powders, pellets, scrap) as part of inspections at nuclear fuel fabrication facilities. Current methods require in-field dissolution chemistry, which is time consuming and imposes operational challenges. Pacific Northwest National Laboratory (PNNL) is developing a prototype spectral x-ray radiography (SpecX) nondestructive assay system for noninvasive material mass quantification of uranium-bearing powders. The SpecX system uses a custom material estimation algorithm, which requires a high-fidelity pixel-by-pixel detector response model for accurate quantification. We performed a detailed characterization and built a model of a High-Energy X-ray Imaging Technology (HEXITEC) CdTe pixelated spectral detector. Here we present the detector characterization which led to that model, including a determination of the pixel-wise energy calibration, the detection efficiency, the detector uniformity, the detector stability, and a comparison of methods to remove charge-shared events.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Catalysis Today〈/p〉 〈p〉Author(s): Haibiao Yu, Xinping Wang, Ye Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉For the Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/CaCO〈sub〉3〈/sub〉 catalysts used for N〈sub〉2〈/sub〉O decomposition, the activity of the catalyst prepared by stepwise precipitation is much superior to the catalysts prepared by impregnation or coprecipitation in the same composition. HRTEM observation and EDX analysis indicate that the stepwise precipitation leads to cobalt existing as little Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 crystallites tightly bound to the CaCO〈sub〉3〈/sub〉 particles. The special structure made the Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 ideal accessibility and better interaction with the support in the catalyst, and the CaCo〈sub〉2.5〈/sub〉(SP) catalyst with this structure is much more active than the CaCo〈sub〉2.5〈/sub〉 catalyst reported in literature prepared in traditional method. At 300 °C, N〈sub〉2〈/sub〉O in the feed gas 2000 ppmv N〈sub〉2〈/sub〉O/Ar was completely converted over the CaCo〈sub〉2.5〈/sub〉(SP) at 20,000 h〈sup〉−1〈/sup〉. Moreover, the CaCo〈sub〉2.5〈/sub〉(SP) catalyst exhibited better resistance to sintering at 800 °C and quite high activity under the presence of 5 vol% O〈sub〉2〈/sub〉 and 2 vol% H〈sub〉2〈/sub〉O at 350 °C as well.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0920586118311611-ga1.jpg" width="361" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): Payam Sotoudeh, Mohsen Ghaemian, Hamid Mohammadnezhad〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Seismic analysis of complex structures such as concrete dams has been the subject of numerous studies. One of the challenges in seismic analysis of such systems is proper modelling of massed foundation. Since concrete dams’ foundations are usually layered, this makes the homogenous half-space assumption relatively unrealistic. In this paper, the effects of massed layered foundation on seismic response of concrete gravity dams in dam-reservoir-foundation systems are investigated. Seismic finite element analysis of the system carried out using domain reduction method. This approach is compared with another available method named, free-field column. First set of analysis considers the effect of modular ratio between layers on seismic response of the gravity dam. Second set of analyses investigate the effects of layers’ geometry, location and orientation on obtained responses. Results highlight the considerable effects of massed layer foundation assumption against its homogenous counterpart. Besides, results show that layer properties dictate how severely they can affect the dynamic responses of the dam.〈/p〉〈/div〉