ALBERT

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〉 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〉 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〉 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: 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 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: 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〉

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): Xing Peng, Xian Wei, Tieyu Chen〈/p〉

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: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 210〈/p〉 〈p〉Author(s): Peng Qu, Xiaohua Ma, Wansong Chen, Dandan Zhu, Huifei Bai, Xiuhua Wei, Shu Chen, Maotian Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new ratiometric fluorescent probe (〈strong〉1〈/strong〉) was developed for the detection of hydrazine. The probe was obtained by incorporating the recognition moiety of acetyl group onto a coumarin fluorophore. Probe 〈strong〉1〈/strong〉 displayed a distinct cyan emission in a 100% aqueous phosphate buffer solution. In the presence of hydrazine, probe 〈strong〉1〈/strong〉 undergoes a hydrazinolysis process to release the coumarin fluorophore, which exhibited significant hypsochromic shifts in both absorption and emission spectra, and thus achieving a ratiometric response. This ratiometric probe is highly selective and sensitive towards hydrazine detection. The limit of detection (LOD) was calculated to be 34 nM. Moreover, cellular toxicity and imaging experiments suggested that probe 〈strong〉1〈/strong〉 is can be used to monitor hydrazine in live cells.〈/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-S1386142518309983-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): Prajakta R. Jadhav, Amit Prashant〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A double wedge model has been proposed to compute seismic sliding displacements of cantilever retaining walls. Experimental observations indicate formation of rupture planes in the form of an inverted triangular wedge in the backfill of retaining walls. Computation of critical yield acceleration at each time instant considering the v-shaped weakest rupture planes which evolve during the ground motion is the preliminary aim of the double wedge model. The model computes translational displacements considering the relative movement of soil wedge along these rupture planes. It considers velocity compatibility along with the acceleration compatibility between the wall and soil wedge. It also computes approximate depth of subsidence of the backfill soil during ground motion. A simplified double wedge model has been also considered wherein the yield acceleration at all time instants is computed with respect to a fixed wedge. The double wedge model and its simplified version have been compared with different cases studies, which show the seismic sliding displacements matching well with the real measurements.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): Wang Hai-tao, Shen Jiayu, Wu Feng, An Zhiqiang, Liu Tianyun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Combined with the plasticity - damage constitutive model of hydraulic concrete obtained from the test by considering the strain rate effect, the elastic-plastic numerical simulation of Koyna concrete gravity dam under different seismic waves is carried out with ABAQUS software. The effect of strain rate on the dynamic performance of concrete gravity dam under earthquake is discussed by comparing the results of high strain rate and quasi-static loading. The results show: when the peak acceleration is small, the acceleration and displacement of the feature point calculated by considering the strain rate effect are smaller than those without considering the strain rate effect, and the difference is not obvious. With the increase of the seismic peak acceleration, the difference gradually increases. Considering the effect of concrete strain rate, the principal tensile stress in the dam is higher than without considering the strain rate, and more in accordance with the actual damage form. It is suggested that the strain rate effect of concrete should be considered in the seismic response analysis of concrete gravity dam.〈/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): Na-Na Li, Yu-Qing Ma, Xue-Jiao Sun, Ming-Qiang Li, Shuang Zeng, Zhi-Yong Xing, Jin-Long Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A simple naphthalene derivative, 6-hydroxy-2-naphthohydrazide (〈strong〉NAH〈/strong〉), was designed and synthesized through two facile steps reactions with the 6-hydroxy-2-naphthoic acid (NCA) as the starting material. In neat H〈sub〉2〈/sub〉O (10% 0.01 M HEPES buffer, v/v, pH = 7.4), probe 〈strong〉NAH〈/strong〉 showed a highly selective and sensitive response towards Fe〈sup〉3+〈/sup〉 via perceptible color change and displayed “turn-on” dual-emission fluorescence response for Cu〈sup〉2+〈/sup〉. The binding stoichiometry ratio of 〈strong〉NAH〈/strong〉/Cu〈sup〉2+〈/sup〉 and 〈strong〉NAH〈/strong〉/Fe〈sup〉3+〈/sup〉 were all confirmed as 1:1 by the method of fluorescence job's plot and UV–Vis job's plot, respectively. Probe 〈strong〉NAH〈/strong〉 can be used over a wide pH range for the determination of Fe〈sup〉3+〈/sup〉 (2.0–10.0) and Cu〈sup〉2+〈/sup〉 (6.0–10.0) without interference from other co-existing metal ions. A possible detection mechanism was the hydrolysis of 〈strong〉NAH〈/strong〉 upon the addition of Fe〈sup〉3+〈/sup〉 or Cu〈sup〉2+〈/sup〉, thereby leading to the formation of 6-hydroxy-naphthalene-2-carboxylic acid (〈strong〉NCA〈/strong〉) which was further confirmed by the various spectroscopic techniques including FT-IR, 〈sup〉1〈/sup〉H NMR titration and HRMS. Moreover, 〈strong〉NAH〈/strong〉 was successfully applied to the detection of Cu〈sup〉2+〈/sup〉 and Fe〈sup〉3+〈/sup〉 in tap water, ultrapure water and BSA.〈/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-S138614251831028X-ga1.jpg" width="333" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Chuang Liu, Keyin Liu, Minggang Tian, Weiying Lin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrazine and its derivatives are one of the most important raw chemical materials that have extensive utilization in many areas. It is also widely applied as pharmaceutical derivatives, such as the antipsychotic drug, anti-infective drug, and antitumor drug. However, hydrazine is a highly toxic reagent which can bring severe damage to human and animals. Herein, we have reported a new benzothiazole substituted naphthalene based probe for hydrazine with huge fluorescence change ratio. The fluorescence change ratio at F〈sub〉390〈/sub〉/F〈sub〉509〈/sub〉 is up to 200-fold in the presence of hydrazine in 60 min. The probe exhibited negligible cytotoxicity toward HeLa cells and was applied for hydrazine detection successfully in HeLa cells.〈/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-S1386142518310886-ga1.jpg" width="447" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Qingming Wang, Lei Jin, Wenling Wang, Lihui Dai, Xiaoxue Tan, Cong Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work, two turn-on fluorescent probes (3-acetyl-2H-chromen-2-one (〈strong〉ACO〈/strong〉) & (1E)-1-(1-(2-oxo-2H-chromen-3-yl)ethylidene)thiosemicarbazide (〈strong〉CETC〈/strong〉)) based on coumarin have been designed and synthesized, which could selectively and sensitively recognize ClO〈sup〉−〈/sup〉 with fast response time. 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 were almost non fluorescent possibly due to both the lacton form of coumarin and unbridged C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉N bonds which can undergo a nonradiative decay process in the excited state. Upon the addition of ClO〈sup〉−〈/sup〉, 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 were oxidized to ring - opened by cleavage the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O and C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉N and the fluorescence intensity were increased considerably. Fluorescence titration experiments showed that the detection limit 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 is as low as 22 nm and 51 nm respectively. In particular, some relevant reactive species, including 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉OH, 〈sup〉1〈/sup〉O〈sub〉2〈/sub〉, H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉, KO〈sub〉2〈/sub〉, some anions and cations cannot be interference with the test. In live cell experiments, 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 were successfully applied to image exogenous ClO〈sup〉−〈/sup〉 in HepG2 cells. Therefore, 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 not only could image ClO〈sup〉−〈/sup〉 in living cells but also proved that C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O and C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉N can be cleavage by ClO〈sup〉−〈/sup〉.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉Two new coumarin-based fluorescent probes were synthesized and successfully achieved for the efficient detection of ClO〈sup〉−〈/sup〉 as turn - on fluorescence chemosensors in Tris - HCl buffer/DMSO (〈em〉v〈/em〉:〈em〉v〈/em〉 = 9:1, 20 mM, 〈em〉pH〈/em〉 = 7.0) with the detection of limit (LOD) as low as 22 nM and 51 nM, respectively.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310825-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Anees A. Ansari, Naushad Ahmad, Joselito P. Labis, Ahmed Mohamed El-Toni, Aslam Khan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tb-doped Y〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 microspheres (MSs) were prepared via a homogeneous thermal degradation process at a low temperature and then coated with a nanosilica shell (Y〈sub〉2〈/sub〉O〈sub〉3〈/sub〉:Tb@SiO〈sub〉2〈/sub〉) using a sol-gel process. The core MSs were highly crystalline and spherical with a porous surface, single cubic phase, and particle size of 100–250 nm. Transmission electron microscopy (TEM) images clearly showed the spherical shape of the as-prepared core MSs, which were fully covered with a thick and mesoporous nanosilica shell. Fourier transform infrared (FTIR) spectra displayed the well-resolved infrared absorption peaks of silica (Si〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O, Si〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Si, etc.), confirming the presence of the silica surface coating. The core MSs retained their spherical shape even after heat treatment and subsequent silica surface coating. It was observed that the core/shell MSs are easily dispersible in aqueous media and form a semi-transparent colloidal solution. Ultraviolet/visible and zeta potential studies were tested to prove the changes in the surface chemistry of the as-designed core/shell MSs and compare with their core counterpart. The growth of the amorphous silica shell not only increased the particle size but also enhanced remarkably the solubility and colloidal stability of the MSs in aqueous media. The strongest emission lines originating from the characteristic intra-shell 4f-4f electronic transitions of Tb ions were quenched after silica layer deposition, but the MSs still showed strong green (〈sup〉5〈/sup〉D〈sub〉4〈/sub〉 → 〈sup〉7〈/sup〉F〈sub〉5〈/sub〉 at 530–560 nm as most dominant) emission efficiency, which indicates great potential in fluorescent bio-probes. The emission intensity is discussed in relation to the quenching mechanism induced by surface silanol (Si-OH) groups, particle size, and surface charge.〈/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-S1386142518310771-ga1.jpg" width="267" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Elisabetta Cattoni, Diana Salciarini, Claudio Tamagnini〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent years, much attention has been paid to performance–based design of flexible retaining structures, focusing on the evaluation of the permanent deformations of the soil–structure system caused by given seismic loads, rather than on the assessment of conventional safety factors determined by comparing seismic actions and system resistance (typically based on limit equilibrium methods). While only a few examples of fully coupled, dynamic numerical simulations of flexible retaining structures adopting advanced cyclic/dynamic models for soils can be found in literature, a number of recent works have proposed simple modifications of the classical Newmark method to assess the permanent displacements of the structure at the end of the seismic excitation. Most of the aforementioned works refer to cantilevered diaphragm walls, for which the failure mechanisms at limit equilibrium are relatively simple to describe. However, this is not the case for anchored or propped flexible structures, where the velocity field at failure under a pseudo–static seismic load is quite complex and can be affected by the plastic yielding of the wall upon bending. In this work, upper– and lower–bound limit analysis FE solutions are used as a basis for the development of a Generalized Newmark Method, based on the accurate evaluation of the critical accelerations for the retaining structure and the corresponding failure mechanisms. It can be shown that, under two reasonable simplifying assumptions, a Newmark–like scalar dynamic equation of motion can be derived which, upon double integration in time, provides the magnitude of the permanent displacements associated to each failure mechanism, as provided by limit analysis. This procedure allows the reconstruction of the full permanent displacement field around the excavation, not just the evaluation of horizontal soil movements at selected points. The application of the method to a number of selected prototype excavations demonstrates the potentiality of the proposed approach, which can be extended easily to other complex geotechnical structures.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Marco Furinghetti, Alberto Pavese, Virginio Quaglini, Paolo Dubini〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉In the present work the experimental response of the Curved Surface Slider (CSS) is investigated through an experimental campaign, carried out on a full-scale prototype subjected to both unidirectional and bidirectional tests. The aim of the study is to assess the effect of vertical load, speed and sustained motion on the frictional response of the device and to compare results returned by different displacement trajectories. In order to perform a quantitative evaluation, a mathematical expression to model the decay of the coefficient of friction as a function of energy dissipation is proposed and calibrated upon experimental data.〈/p〉 〈p〉Though at low vertical load non-negligible discrepancies between unidirectional and bidirectional orbits were noticed, the CSS device shows consistent behaviour as the applied load, and consequently the dissipated energy, are increased. The results allow to draw some guidance for the estimation of the design variation range of the friction coefficient of Curved Surface Slider devices used to perform bound analyses.〈/p〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Yuan Yao, Jie Chen, Tao Li, Bo Fu, Haoran Wang, Yuehua Li, Hailiang Jia〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soil liquefaction is a type of coseismic hydrological change triggered by earthquakes, and its occurrence results in major property damage and casualties. The dynamics of coseismic hydrological changes are not fully understood. In order to address this, we studied coseismic deformations such as liquefaction and ground fissures that occurred as a result of strong seismic activity during the 2016 Mw6.6 Akto earthquake, which took place in the interior of the Pamir Plateau in northwestern China. This paper presents a systematic survey of the frozen soil liquefaction and ground fissures caused by this earthquake. The majority of liquefaction sites near the Karaat River are located on the T1 terrace, in Bulake village, and are adjacent to the alluvial fan of the Kungai Mountain. We find that the liquefaction was caused by the original spring and coseismic ground fissure during the earthquake. Approximately 80% of the liquefaction sites are formed along the original spring in the epicenter. The maximum height of sand boils is 15 cm. The remaining 20% of the liquefaction sites are formed along the coseismic ground fissure. Our results suggest that the frozen soil layer impedes liquefied material in the lower unfrozen soil layer from reaching the surface, and the material formed from liquefaction is consequentially channeled through the primary fault and coseismic ground fissures. Liquefaction associated with the Akto earthquake demonstrates the importance of accounting for the possibility of a series of coseismic geological disasters, such as soil liquefaction and ground fissures, in areas with similar geology, altitude, and temperature.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Li Zhang, Mingzhou Su, Chao Zhang, Hua Shen, Md Mofakkharul Islam, Ruifu Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The traditional design method of the elastic response reduction curve (ERRC) was used to design the parameters of the viscoelastic damper (VED), where the plastic behavior of the primary structure is neglected. Considering the structural plastic behavior, in this study, a direct design method is proposed to obtain the parameters of VEDs based on the elastic-plastic response reduction curve (EPRRC), which can illustrate the relationship between damper parameters and the response reduction effect in the elastic-plastic stage. First, the ERRC is developed to the EPRRC, and the differences between them are compared using the displacement and acceleration response difference ratios, which demonstrate an overestimated response reduction effect of VEDs in the elastic-plastic stage using the ERRC. Then, the corresponding design procedures are given based on the EPRRC by referring to the direct displacement-based design theory. Finally, a benchmark model is used to illustrate the effectiveness of this proposed design method by conducting a time history analysis. The analysis results indicate that the target story drift of the structure can be satisfied under different earthquake intensities using VEDs. Thus, based on this study, the development of the EPRRC can be considered worthwhile, and the proposed design method of VED parameters is easy to implement and is effective.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Hongwei Ren, Xue Wang, Shaohan Lian, You Zhang, Erhong Duan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Deep eutectic solvents (DES) are generally composed of two or three cheap and safe components that are associated with each other via hydrogen bonds. The formation Caprolactam (CPL)-tetraalkyl ammonium halide (TAAX) DES and its hydrate were investigated using React IR. TAAX was introduced to CPL in the molten state at 353.15 K, the intermolecular H-N-C=O⋯H-N-C=O hydrogen bonds (CPL dimer) transfer to X〈sup〉−〈/sup〉⋯H-N-C=O (CPL-TAAX DES). When water was added to CPL-TAAX DES, intermolecular X〈sup〉−〈/sup〉⋯H-N-C=O⋯H-O-H hydrogen bonds appeared, and CPL-TAAX DES hydrate was formed. However, if the ratio of water exceeded the moral fraction of 0.61, CPL-TAAX DES hydrate turned into a CPL-TAAX aqueous solution. The C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O (1660 cm〈sup〉−1〈/sup〉) bonds were linearly correlated with hydrogen bonds number and TBAB amount in CPL-TBAB DES. When the molar fraction of CPL-TBAB DES was 0.39 to 0.78, the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O peak redshift has a better linear correlation with water. Halide anions and the alkyl chain length of TAAX have little influence on the redshifts and peak intensity of the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O peak.〈/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-S1386142518310679-ga1.jpg" width="344" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Abdel Majid A. Adam, Hala H. Eldaroti, Mohamed S. Hegab, Moamen S. Refat, Jehan Y. Al-Humaidi, Hosam A. Saad〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In our previous work, we highlighted the thermodynamic and spectroscopic characteristics of the 1:1 charge transfer (CT) complexation of TCNE acceptor with various medically important drugs. Continuing that work, we further examine drugs that react with the TCNE acceptor via a 1:2 interaction. The examined drugs are atenolol, quinidine, cimetidine, reserpine, and levofloxacin. We aimed through this study to: 〈em〉i〈/em〉) make the spectrophotometric and thermodynamic data of the examined drugs, both initially and when reacted via a 1:2 M ratio with the TCNE acceptor, available to use in the determination or detection of these drugs in pharmaceuticals and other environments; and 〈em〉ii〈/em〉) compare the mode of interactions and the spectrophotometric and thermodynamic properties between drugs that react via a 1:1 or 1:2 ratio with the TCNE acceptor. To achieve these aims, the five examined drugs were reacted with TCNE in acetonitrile (MeCN) solvent at room temperature. Several thermodynamic and spectroscopic data were experimentally estimated using the van't Hoff and the Benesi–Hildebrand equations and discussed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉Electronic absorption spectrum of the CT product that formed form the reaction of drug Qui with TCNE acceptor in MeCN solvent.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310709-ga1.jpg" width="455" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): G. Kampas, J.A. Knappett, M.J. Brown, I. Anastasopoulos, N. Nikitas, R. Fuentes〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Major seismic events have shown that tunnels in cohesionless soils may suffer extensive seismic damage. Proper modelling can be of great importance for predicting and assessing their seismic performance. This paper investigates the effect of lining structural modelling on the seismic behaviour of horseshoe-shaped tunnels in sand, inspired from an actual Metro tunnel in Santiago, Chile. Three different approaches are comparatively assessed: elastic models consider sections that account for: (a) linear elastic lining assuming the geometric stiffness; (b) linear elastic lining matching the uncracked stiffness of reinforced concrete (RC); and (c) nonlinear RC section, accounting for stiffness degradation and ultimate capacity, based on moment-curvature relations. It is shown that lining structural modelling can have major implications on the predicted tunnel response, ranging from different values and distributions of the lining sectional forces, to differences in the predicted post-earthquake settlements, which can have implications on the seismic resilience of aboveground structures.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Yingping Li, Yong Jia, Qi Zeng, Xiaohui Jiang, Zhengjun Cheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We used thiamine nitrate (TN) as single material to fabricate nitrogen and sulfur co-doped carbon quantum dots (N,S-CQDs) with a quantum yield of 10.4% through one-pot hydrothermal method, and its properties were characterized by TEM, XPS, FTIR, fluorescence (FL) and UV–vis spectrophotometer, respectively. The fluorescence of N,S-CQDs was effectively quenched in the presence of vitamin B12 (VB12)/tartrazine due to Förster resonance energy transfer (FRET). Moreover, the rate (〈em〉K〈/em〉〈sub〉T〈/sub〉) and efficiency (〈em〉E〈/em〉%) of energy transfer from N,S-CQDs (as a donor) to VB12/tartrazine (as an acceptor) enhanced with increasing the concentrations of acceptor, and the 〈em〉K〈/em〉〈sub〉T〈/sub〉 and 〈em〉E〈/em〉% were also varied with the change of excitation wavelengths (from 338 to 408 nm). Based on this principle, a multifunctional fluorescence probe was designed for selective and sensitive detection of VB12/tartrazine with a detection limit (3σ/slope) of 15.6/18.0 nmol/L. Meanwhile, the proposed method was successfully employed to detect VB12/tartrazine in milk and several beverages with a recovery range of 97.5–104.2%/91.0–110.6%.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉N,S-CQDs as a multifunctional sensor has remarkable selectivity and high sensitivity for monitoring VB12/tartrazine, and the FL quenching of N,S-CQDs by VB12/tartrazine was further analyzed by FRET theory. The 〈em〉r〈/em〉 values decrease with increasing the concentration of acceptor (VB12/tartrazine) (A/B), and corresponding 〈em〉E〈/em〉% and 〈em〉K〈/em〉〈sub〉T〈/sub〉 values (C/D) show an opposite change tendency.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310643-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Xiao Wang, Yanmei Zhou, Chenggong Xu, Haohan Song, Xiaobin Pang, Xiaoqiang Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrazine (N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉) and fluoride ion (F〈sup〉−〈/sup〉) are regarded as environmental pollutants and potential carcinogens. A dual-functional fluorescent probe (probe 〈strong〉1〈/strong〉) was developed for both F〈sup〉−〈/sup〉 and N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 with high selectivity and sensitivity. 〈strong〉1〈/strong〉 was based on nucleophilic aromatic substitution reaction for N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 detection and selective cleavage of 4-nitrobenzenesulphonyl group for the determination of F〈sup〉−〈/sup〉. The limits of detection of probe for F〈sup〉−〈/sup〉 and N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 were 77.82 nM and 29.34 nM, respectively, which are far below the threshold limit value (TLV) of United States Environmental Protection Agency (EPA). The home-made test strips of 〈strong〉1〈/strong〉 provided the positive tool for F〈sup〉−〈/sup〉 and gaseous N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 in different system. And the confocal fluorescence images indicated that 〈strong〉1〈/strong〉 can quantitatively detect N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 in living PC12 cells. Promisingly, 〈strong〉1〈/strong〉 has great prospects for N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 imaging and determining in living system.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉A 4-nitrobenzenesulphonyl group-cleavage based fluorescent probe was prepared for highly selective and sensitive dual-detection of fluoride ion and gaseous hydrazine on home-made test strips. This probe was successfully applied to quantitatively detect hydrazine in living cells.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310667-ga1.jpg" width="317" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Jian Zhu, Xiao-Hong Chen, Jian-Jun Li, Jun-Wu Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, the novel tetrapod gold nanostars with four specific numbers of sharp tips were synthesized with good uniformity, high yield and chemical stability. The size of tetrapod gold nanostars has been increased effectively by increasing the amount of HAuCl〈sub〉4〈/sub〉 or DEA added to the reaction solution, and the corresponding in-plane localized surface plasmon resonance (LSPR) band can shift from 700 to 1100 nm. In order to combine the advantages of different metals, the Ag-coated tetrapod gold nanostars were prepared with different Ag coating thicknesses by increasing the volume of AgNO〈sub〉3〈/sub〉. With the increase of Ag coating thickness, the morphology of the nanoparticles has changed from gold nanostars with four sharp tips to bimetallic cuboids with four sharp tips and finally to crore-shell cuboids completely. The surface-enhanced Raman scattering (SERS) activity of Ag-coated tetrapod gold nanostars has also been improved with the different Ag coating thicknesses. Combined the tip effect and the enhancement effect of Ag, the SERS activity has the strongest enhancement when the four sharp tips of tetrapod gold nanostars are not completely coated by the Ag layer but still exposed to the outsides. For tetrapod gold nanostars with larger size to grow Ag-coated tetrapod gold nanostars, the bimetallic cuboids with four sharp tips nanostructure have the biggest SERS enhancement factor (EF) of 1.73 × 10〈sup〉6〈/sup〉 for Rhodamine 6G (R6G), making it an ideal candidate in SERS-based sensing application.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉The SERS activity has been strongly improved when the four sharp tips of tetrapod gold nanostars (In-plane LSPR at 916 nm) are not completely coated by the Ag layer but still exposed to the outsides.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310631-ga1.jpg" width="284" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Rupa Pegu, Gopal Pandit, Ankur Kanti Guha, Sajal Kumar Das, Sanjay Pratihar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this report, 6〈em〉H〈/em〉-indolo[2,3-〈em〉b〈/em〉]quinoline (hereafter 〈strong〉2a〈/strong〉) was synthesized and employed as an optical chemosensor for fluoride. The sensitivity of 〈strong〉2a〈/strong〉 towards fluoride was established from the change in both the absorption and emission signals. The various 〈em〉in-situ〈/em〉〈sup〉1〈/sup〉H NMR, UV–Vis, and density functional studies indicate that the 1:2 binding interaction between 〈strong〉2a〈/strong〉 and fluoride followed by deprotonation to its corresponding di-anion (〈strong〉2a〈/strong〉〈sup〉〈strong〉2−〈/strong〉〈/sup〉), which in turn boosted the donor-acceptor interaction between indole and quinoline moiety in 〈strong〉2a〈/strong〉〈sup〉〈strong〉2−〈/strong〉〈/sup〉〈em〉via〈/em〉 expansion of torsion angle by 10.2° as compared to 〈strong〉2a〈/strong〉. Consequently the significant changes in both the absorption and emission signal of 〈strong〉2a〈/strong〉 allow us to detect and estimate the concentration of fluoride up to 0.2 μM from the mixture of different anions.〈/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-S1386142518310618-ga1.jpg" width="431" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Hui Chen, Chao Tan, Zan Lin, Hongjin Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The authentication of traditional Chinese medicine (TCM) is critically important for public-health and economic terms. Notoginseng, a classical TCM of high economic and medical value, could be easily adulterated with 〈em〉Sophora flavescens〈/em〉 powder (SFP), corn flour (CF) or other analogues of low-grade (ALG) because of their similar tastes, appearances and much lower cost. The main objective of this study was to evaluate the feasibility of applying of near-infrared (NIR) spectroscopy and multivariate calibration for identifying and quantifying several common adulterants in notoginseng powder. Two datasets were prepared for experiment. The competitive adaptive reweighted sampling (CARS) was used to select informative variables. Two different schemes were used for sample set partition. Model population analysis (MPA) was made. The results showed that, the constructed partial least squares (PLS) model using a reduced set of variables from CARS can provide superior performance to the full-spectrum PLS model. Also, the sample set partition is very of great importance. It seems that the combination of NIR spectroscopy, CARS and PLS is feasible to quantify common adulterants in notoginseng powder.〈/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-S1386142518310655-ga1.jpg" width="267" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Ruifeng Liu, Zheming Zhu, Meng Li, Bang Liu, Duanying Wan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dynamic fracture behavior under impacting loads has been well studied, but for that under blasting loads, less attention has been paid. In order to investigate mode I crack propagation behavior of brittle materials under blasting, a new configuration specimen, i.e. single internal crack circular disc (SICCD) specimen was proposed in this paper, and it was applied in the blasting experiments. Crack propagation gauges (CPGs) were stuck along crack propagation paths to measure crack initiation and propagation time and crack propagation speeds. Green sandstone and PMMA were selected to make the SICCD specimens. Finite difference models were established by using AUTODYN code according to the SICCD specimen dimension and the loading curve measured near the borehole. Generally, the simulation results of crack propagation paths agree with the test results. Finite element code ABAQUS was applied in the calculation of dynamic stress intensity factors (SIFs), and the curves of dynamic SIFs versus time were obtained. By using these curves and the breaking time of the CPG wires, the mode I critical dynamic SIFs in initiation and in propagation were obtained. The results show that the measuring method of the critical dynamic SIFs of brittle materials under blasting presented in this paper is feasible and applicable. During crack propagations, the crack speed is not a constant, and the critical dynamic SIFs in propagation decreases with the increase of crack propagation speeds.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Graham Hungerford, M. Adília Lemos, Boon-Seang Chu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The binding of an extract from the flowers of 〈em〉Clitoria ternatea〈/em〉 L. to the digestive enzyme α-amylase was investigated. This extract is a mixture of flavonoids, including anthocyanins, and has been previously shown to inhibit the activity this enzyme. This has implications for modulating starch digestion. In order to investigate the kinetics, we made use of time-resolved fluorescence to simultaneously monitor two different emission bands emanating from the extract. This measurement was enabled by the use of a “photon streaming” approach and changes in fluorescence lifetime and intensity were used to follow the interaction. A longer wavelength band (655 nm) was ascribed to anthocyanins in the mixture and these were observed to bind at a rate an order of magnitude slower than other flavonoids present in the extract, monitored at a shorter wavelength (485 nm). Changes in the fluorescence emission of the extract upon binding were further assessed by the use of decay associated spectra.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉Binding of 〈em〉C. ternatea〈/em〉 extract to α-amylase followed using time-resolved fluorescence monitoring 2 wavelengths simultaneously using a photon streaming approach.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S138614251831059X-ga1.jpg" width="480" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Xiaojing Yang, Yingying Wang, Mei-xia Zhao, Wei Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉By introducing the S-aryl substituents at the central carbon on heptamethine cyanine, we have developed a near-infrared fluorescent probe Cy.7-PT. The probe had the high selectivity for the colorimetric detection of Cys/Hcy with the color changing from light green to blue. Cys could be quantitatively detected and the detection limit is 0.39 μM. Cell imaging and spiked samples experiments prove that the probe Cy.7-PT is suitable for monitoring and visualizing Cys in vitro and living cells.〈/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-S1386142518311120-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Mao-Sen Xu, Chuan-Lu Yang, Mei-Shan Wang, Xiao-Guang Ma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To evaluate the feasibility of the laser cooling of CuH molecule, we investigate the electronic properties, the vibrational and rotational characteristics of the molecule based on the multi-reference configuration interaction method with all-electron basis sets. The potential energy curves (PECs) of X〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉, A〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉, B〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉, a〈sup〉3〈/sup〉Σ〈sup〉+〈/sup〉, b〈sup〉3〈/sup〉Σ〈sup〉+〈/sup〉, e〈sup〉3〈/sup〉Σ〈sup〉+〈/sup〉, C〈sup〉1〈/sup〉П, D〈sup〉1〈/sup〉П, c〈sup〉3〈/sup〉П and d〈sup〉3〈/sup〉П states and the transition dipole moments between these states are calculated. The Schrödinger equation of nuclear movement is solved for each electronic state to obtain the rotational and vibration energy levels. The spectroscopic parameters are calculated based on the fitted analytical function from the PECs. The present results are in good agreement with the theoretical and experimental values available in the literature. The optical scheme of the laser cooling for CuH molecule is constructed with A〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉 ↔ X〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉 as the close-loop transition. Three lasers are necessary in each direction to maintain enough scattering photons because of the limited Franck-Condon factor of 0.78. The wavelengths of the pumping lasers are determined. The recoil temperature is 1.72 μk, which is the expected temperature to be reached through the method of the cooling below the doppler limit.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉The laser cooling scheme of CuH molecule has been constructed with the closed transition of A〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉 ↔ X〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉 and three pumping lasers.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518311089-ga1.jpg" width="318" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): V. Charles Vincent, K. Kirubavathi, G. Bakiyaraj, K. Selvaraju〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The solution grown structure 4-hydroxy L-proline cadmium chloride (4HLPCC) single crystal has been done by means of X-ray diffraction method. The computational quantum mechanical modelling method was performed with B3LYP level and LanL2DZ basis set to determine optimized geometry, dipolar moment, linear polarizability, first order hyperpolarizability, atomic charges of various atoms, thermodynamic parameters, HOMO-LUMO energy gap and vibrational frequencies of 4HLPCC. The vibrational frequencies of 4HLPCC were observed experimentally through FTIR and FT-RAMAN analyses and compared with theoretical frequencies. The electric properties were detected by dielectric studies. The frequency doubling of the grown crystal was made with Kurtz-Perry powder technique.〈/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-S1386142518311077-ga1.jpg" width="347" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Shiwen Zhang, Qiang Shen, Chaojia Nie, Yuanfang Huang, Jianhua Wang, Qingqing Hu, Xuejiao Ding, Yan Zhou, Yuanpeng Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Conventional methods for investigating heavy metal contamination in soil are time consuming and expensive. We explored reflectance spectroscopy as an alternative method for assessing heavy metals. Four spectral transformation methods, first-order differential (FDR), second-order differential (SDR), continuum removal (CR) and continuous wavelet transform (CWT), are used for the original spectral data. Spectral preprocessing effectively eliminated the noise and baseline drifting and also highlighted the locations of the spectral feature bands. Partial least squares regression (PLSR) and radial basis function neural network (RBF) were used to study the hyperspectral inversion of four heavy metals (Cr, As, Ni, Cd). The inversion models of four heavy metals were established in the bands with the highest correlation coefficient. The inversion effects were evaluated by the coefficient of determination (〈em〉R〈/em〉〈sup〉2〈/sup〉), root mean square error (RMSE) and residual predictive deviation (RPD) indexes. The 〈em〉R〈/em〉 values of the correlation coefficient were significantly improved after smoothing and spectral transformation compared to the original waveband. The method combining continuous wavelet transform (CWT) with radial basis function neural network (RBF) had the best inversion effect on the four heavy metals. When compared to partial least squares regression (PLSR), the RMSE values were reduced by approximately 2. The CWT-RBF method can be used as a means of inversion of heavy metals in mining wasteland reclaimed land.〈/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-S1386142518311028-ga1.jpg" width="348" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/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): 〈/p〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 118〈/p〉 〈p〉Author(s): Zhang Zhi, Li Xiaojun, Lan Riqing, Song Chenning〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Focusing on a small radius curved bridge, a serious of shaking table tests and corresponding numerical finite element analyses were conducted for a 1/16 scaled curved bridge model considering SSI (Soil-Structure Interaction) effect. In the testing and simulating, the strong motion records with different frequency characteristics and durations, El Centro record from Ms6.7 Imperial Valley earthquake and Wolong record from Ms8.0 Wenchuan earthquake, were as the input motions. The dynamic property, vibration response, damage rule, and failure mode of the curved bridge were obtained preliminarily. The experimental results showed that the transverse stiffness of this soil-pile-bridge structure system was larger than the longitudinal stiffness; the obvious torsion effect of the model structure was observed in the tests under the input motion in uni-direction, and the larger was the input motion PGA, more obvious was the torsion effect; the seismic responses were more sensitive to input motions with relative low-frequency components; the damage degree of the pier bottom increased from short to high pier, and the rubber bearings at side piers appeared two different failure modes induced by the longitudinal slope. Compared with straight bridges, the curvature radius made curved bridges more prone to causing rotation and displacement. Furthermore, finite element analyses were conducted by using the plastic-damage model for concrete, and equivalent soil springs method for pile-soil interaction, respectively. The simulations were in agreement with the test results satisfactorily, moreover the differences between these results were discussed in detail and the errors were in an acceptable range. These studies would be used to provide insights for the further research and theoretical design of curves bridges.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 23 February 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering〈/p〉 〈p〉Author(s): Hiroshi Kawase, Fumiaki Nagashima, Kenichi Nakano, Yuta Mori〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Horizontal-to-Vertical spectral ratios of microtremors (MHVR) have been utilized as a convenient tool to extract a predominant frequency at a target site. The so-called “Nakamura” method, which was proposed by Nakamura in 80's, assumed that MHVR provides us directly the S-wave amplification factor of earthquake in the horizontal component, that is, Horizontal-to-Horizontal spectral ratio (HHR) with respect to the bedrock, although the validity of the method had never been proved. Recently, based on the diffuse field concept (DFC) proposed by Sánchez-Sesma and others in 2011 MHVRs are found to correspond to the square root of the ratio of the imaginary part of the displacement for a unit harmonic load in the horizontal direction with respect to the corresponding one in the vertical direction. With the same DFC for body waves Horizontal-to-Vertical spectral ratios of earthquake (EHVR) correspond to the ratio of the horizontal motion for a vertical incidence of S wave with respect to the vertical correspondent of P wave, as revealed by Kawase and others in 2011. Thus there should be a systematic difference between EHVR and MHVR because of the difference in their primary contribution of wave types. We first calculated the ratios of EHVR with respect to MHVR (EMR) at 100 strong motion stations in Japan. Then we normalized frequency by the fundamental peak frequency at each site and calculated the average of EMRs for five categories based on their fundamental peak frequencies. Once we got empirical EMRs for five categories we transformed MHVRs into pseudo EHVRs. At the same time we calculated the average Vertical-to-Vertical spectral ratios (VVRs) for the same sites using the generalized spectral inversion technique (GIT) of Nakano et al. (2015) [16]. Finally the S-wave amplification factor, HHR, of earthquake ground motion at the site were calculated from MHVR with double corrections using EMR and VVR for the corresponding category. We compared these final empirical prediction with the observed HHRs from GIT to find quite high correlations and small overall residuals. The proposed method to get HHR from MHVR with these double empirical corrections can be considered as a natural but significant extension to the so-called “Nakamura” method.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Kessarin Ngamdee, Kanokwan Chaiendoo, Chatree Saiyasombat, Wutthikrai Busayaporn, Somlak Ittisanronnachai, Vinich Promarak, Wittaya Ngeontae〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A highly selective circular dichroism sensor based on cysteamine-capped cadmium sulfide quantum dots (Cys-CdS QDs) was successfully developed for the determination of Cu〈sup〉2+〈/sup〉. Basically, the Cys-CdS QDs are not active in circular dichroism spectroscopy. However, the circular dichroism probe (DPA@Cys-CdS QDs) can be simply generated 〈em〉in situ〈/em〉 by mixing achiral Cys-CdS QDs with D-penicillamine. The detection principle was based on measuring the circular dichroism signal change upon the addition of Cu〈sup〉2+〈/sup〉. The strong CD signal of the DPA@Cys-CdS QDs dramatically decreased in the presence of Cu〈sup〉2+〈/sup〉, while other cations did not result in any spectral changes. In addition, the degree of the CD signal decrease was linearly proportional to the concentration of Cu〈sup〉2+〈/sup〉 in the range of 0.50–2.25 μM (r〈sup〉2〈/sup〉 = 0.9919) with a detection limit of 0.34 μM. Furthermore, the proposed sensor was applied to detect Cu〈sup〉2+〈/sup〉 in drinking water samples with %recovery values of 102–114% and %RSD less than 6%.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉Cysteamine-capped cadmium sulfide quantum dots (Cys-CdS QDs) were mixed with D-penicillamine (DPA) to generate the sensor probe (DPA@Cys-CdS QDs). The generated chiral CdS QDs were used as a selective sensor for the detection of Cu〈sup〉2+〈/sup〉 by measuring the decrease in the CD intensity.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310953-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Huimin Kang, Congbin Fan, Gang Liu, Shouzhi Pu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new-synthesized diarylethene with near-infrared fluorochrome unit exhibited excellent photochromism under the irradiation of UV light (297 nm) and visible light (〈em〉λ〈/em〉 〉 500 nm). When Cu〈sup〉2+〈/sup〉 was added to the diarylethene solution, a fluorescent emission band centered at 736 nm appeared, indicating that the emission peak wavelength of compound is in near-infrared region. According to data of NMR, MS and other experiments, the complex ratio of the target compound to Cu〈sup〉2+〈/sup〉 was 1:1 in the CH〈sub〉3〈/sub〉CN–H〈sub〉2〈/sub〉O solution (v/v = 9:1) with a limit of detection (LOD) of 0.10 μM. Furthermore, a logic circuit was constructed with four input signals (ultraviolet stimulus, visible light stimulus, Cu〈sup〉2+〈/sup〉 and EDTA) and one output signal (fluorescent intensity at 736 nm).〈/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-S1386142518310965-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Yichen Jin, Tao Pang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Upconversion luminescence and optical temperature sensing properties of Yb〈sup〉3+〈/sup〉/Er〈sup〉3+〈/sup〉/Li〈sup〉+〈/sup〉 tri-doped ZnMoO〈sub〉4〈/sub〉 phosphors were investigated. It has been demonstrated that Li〈sup〉+〈/sup〉 doping affected not only the local symmetry of Yb〈sup〉3+〈/sup〉 and Er〈sup〉3+〈/sup〉 but also the distribution of them in the host lattice. As a result, the significantly improved green upconversion luminescence was obtained when excited at 980 nm. The pumping power dependent photo-thermal behavior was used to evaluate the reliability of upconversion temperature sensing. An accurate temperature scale was established by eliminating the impact of thermal effect, and the sensing ability was evaluated via a comparison with the results reported in literatures.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉Accurate temperature scale based on upconversion luminescence of ZnMoO〈sub〉4〈/sub〉:Yb〈sup〉3+〈/sup〉, Er〈sup〉3+〈/sup〉, Li〈sup〉+〈/sup〉 under 980 nm excitation.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310813-ga1.jpg" width="299" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 21 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering〈/p〉 〈p〉Author(s): Xiao Wei, Jun Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The liquefaction resistance of silty sands and the potential effect of initial static shear stress are major concerns in seismic design of dams and embankments. This paper presents a systematic experimental study on non-plastic silty sands to address these concerns. It is shown that the concept of threshold 〈em〉α〈/em〉 (〈em〉α〈/em〉〈sub〉th〈/sub〉) proposed by Yang and Sze (2011) to characterize the impact of 〈em〉α〈/em〉 (representing the initial static shear stress level) on cyclic resistance (〈em〉CRR〈/em〉) of clean sands is applicable to silty sands as well. When 〈em〉α〈/em〉 〈 〈em〉α〈/em〉〈sub〉th〈/sub〉, 〈em〉CRR〈/em〉 increases with increasing 〈em〉α〈/em〉, otherwise it decreases with increasing 〈em〉α〈/em〉. The threshold 〈em〉α〈/em〉 is affected by the initial packing density, the initial effective confining pressure and the fines content. An improved state dependency of the threshold 〈em〉α〈/em〉, which is regardless of fines content, is proposed in the framework of critical state soil mechanics by using the state parameter (〈em〉ψ〈/em〉). An analysis platform, known as 〈em〉CRR〈/em〉-〈em〉ψ〈/em〉 platform and developed based on clean sand data, is shown to have the capability of characterizing the state dependence of 〈em〉CRR〈/em〉 for sands with varying fines contents. This platform in conjunction with the unified 〈em〉α〈/em〉〈sub〉th〈/sub〉-〈em〉ψ〈/em〉 correlation provides a unified and consistent framework for understanding the complicated effects of initial static shear stress on soil liquefaction and for quantifying such effects for engineering practice.〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 118〈/p〉 〈p〉Author(s): Jun Wang, Zhi Zhou, Xiuqing Hu, Lin Guo, Yuanqiang Cai〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soft clay is subjected to complex cyclic stress paths involving a combination of cyclic vertical and horizontal stress with principal stress rotation caused by traffic load. In this study, three groups of tests, namely tests with principal stress rotation, cyclic confining pressure, and combination of principal stress rotation and confining pressure, were conducted at different load frequencies using Wenzhou soft clay with hollow cylinder apparatus to investigate the undrained cyclic behavior of soft clay. The development of pore water pressure, accumulative strain, axial stress–strain relationship, and resilient modulus were analyzed. Experimental results show that the different stress paths play important roles in the cyclic behavior. The principal stress rotation accelerates the degradation of the resilient modulus due to the accumulation of axial strain. The cyclic confining pressure constrains the development of axial strain, which results in a larger resilient modulus. A lower load frequency results in a larger pore water pressure, accumulative strain, and degradation of resilient modulus. These results provide reference for the assessment of settlement induced by traffic load on soft soils.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 118〈/p〉 〈p〉Author(s): Jiulin Bai, Shuangshuang Jin, Junxian Zhao, Bohao Sun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Endurance time (ET) method is a new approach for assessing the seismic performance of structures. This paper investigated the effectiveness and accuracy of employing ET method to predict the seismic response of soil-structure-interaction (SSI) system. The Chinese code-conforming endurance time acceleration functions (ETAFs) were firstly generated. Two 5- and 10-story reinforced concrete (RC) frame structures were employed as prototype structures. The finite element model of soil-foundation-structure was established based on nonlinear Beam-on-Nonlinear-Winkler-Foundation (BNWF) theory. Nonlinear dynamic analyses of the structural systems subjected to 3 ETAFs and 22 ground motions were carried out. The seismic response of superstructure and foundations, and different SSI models were compared. The results indicate the ET method can predict the seismic response of SSI structural systems, with a high efficiency and accepted accuracy.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Luis A. Pinzón, Luis G. Pujades, Albert Macau, Sara Figueras〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, previous microzonation studies in Barcelona (Spain) were revisited, and available data on the predominant periods of soils in the city were compiled to develop an updated microzonation map of the city. In addition, the building database was updated and used to create a map of building fundamental periods. The crossing of soil predominant period and building fundamental period maps led to the detection of areas in which resonance phenomena and, indeed, increased amplification of the structural response are expected. Thus, zones of Barcelona were identified in which the seismic hazard is probably greater due to resonance effects. The improved microzonation maps and the detection of soil-building resonance areas contribute significantly to enhanced precision and awareness of seismic hazard and risk in Barcelona.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Yang Ding, George P. Mavroeidis, Nikos P. Theodoulidis〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The 1995 〈em〉M〈/em〉〈sub〉w〈/sub〉 6.5 Kozani-Grevena earthquake struck an area in northwestern Greece characterized by relatively low seismicity based on historical information and instrumental data. The ground shaking in the near-fault region was recorded by a strong-motion accelerograph in the city of Kozani, at a distance of about 23 km from the epicenter. In this article, broadband ground motions are generated at selected locations and at a dense grid of observation points extending over the causative fault of the 1995 Kozani-Grevena earthquake using a hybrid deterministic-stochastic method. Based on a multi-segment fault model with curved geometry proposed in the literature, the low-frequency components of the synthetic ground motion are simulated using the discrete wavenumber representation method and the generalized transmission and reflection coefficient technique. The high-frequency components of the synthetic ground motion are generated using the stochastic modeling approach and the specific barrier model. The two independently derived ground-motion components are then combined using matched filtering at a crossover frequency of 1.2 Hz to generate broadband ground-motion time histories and response spectra. The simulation results are validated by comparing the synthetic ground motions with the recorded ones in the city of Kozani and with estimates of peak ground-motion quantities inferred from ground-motion prediction equations.〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 118〈/p〉 〈p〉Author(s): Gopala Krishna Rodda, Dhiman Basu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper explores the possibility of a new parametric representation of auto-spectral density (ASD) that enables extraction of several meaningful insights. Recorded translational ground motions are considered first and the resulting parametric model is capable to address the scenario when seismic energy is distributed over multiple frequency bands. A slightly different form is developed to address the rotational ground motion. Variation of ASD over the footprint of seismic arrays, both large (SMART1) and dense (LSST), is studied. The assessment is based on spectral similitude using spectral contrast angles and distance correlation. Possible correlation of the parameters of the proposed ASD model against site and event characteristics is investigated based on selected ground motions from PEER database. Model parameters thus computed are used in synthetically predicting the ASD of ground motions at the LSST array and that shows good resemblance against the recorded events.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Yan Gong, Huifeng Liang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nickel ions (Ni〈sup〉2+〈/sup〉) were detected by a new imidazole modified carbon dots (CDs) based on fluorescence quenching method. Structural characterization of CD-imidazole quantum dots were accomplished by transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). Spectroscopic properties were characterized by ultraviolet absorption spectrum and fluorescence spectrum. Ni〈sup〉2+〈/sup〉 concentration showed good linear relationship with fluorescence quenching efficiency in the range of 6–100 mM (〈em〉R〈/em〉 = 0.99) and the limit of detection (LOD) was 0.93 mM. Imidazole modified CDs have strong selectivity of Ni〈sup〉2+〈/sup〉 compared with other metal ions in aqueous solution. These results demonstrated that the fluorescence sense platform based on imidazole modified CDs can be applied to Ni〈sup〉2+〈/sup〉 detection in environment.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉A fluorescence aptasensor switch was developed for Ni〈sup〉2+〈/sup〉 detection by imidazole modified carbon dots.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310862-ga1.jpg" width="324" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Yan Liu, Yixin Wang, Zhenzhen Xia, Yingjie Wang, Yongning Wu, Zhiyong Gong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phytosterols have been extensively studied because it plays essential roles in the physiology of plants and can be used as nutritional supplement to promote human health. We use a rapid method by coupling near-infrared spectroscopy (NIRS) and chemometric techniques to quickly and efficiently determine three essential phytosterols (〈em〉β〈/em〉-sitosterol, campesterol and stigmasterol) in vegetable oils. Continuous wavelet transform (CWT) method was adopted to remove the baseline shift in the spectra. The quantitative analysis models were constructed by partial least squares (PLS) regression and randomization test (RT) method was used to further improve the models. The optimized models were used to calculate the phytosterol contents in prediction set in order to evaluate their predictability. We have found that the phytosterol contents obtained by the optimized models and Gas Chromatography/Mass Spectrometry (GC/MS) analysis are almost consistent. The root mean square error of prediction (RMSEP) and ratio of prediction to deviation (RPD) for the three phytosterols are 525.7590, 212.2245, 65.1611 and 4.0060, 4.7195 and 3.5441, respectively. The results have proved the feasibility of the proposed method for rapid and non-destructive analysis of phytosterols in edible oils.〈/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-S1386142518311004-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/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): 〈/p〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Wan Mohd Ebtisyam Mustaqim Mohd Daniyal, Yap Wing Fen, Jaafar Abdullah, Amir Reza Sadrolhosseini, Silvan Saleviter, Nur Alia Sheh Omar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Surface plasmon resonance (SPR) is a label-free optical spectroscopy that is widely used for biomolecular interaction analysis. In this work, SPR was used to characterize the binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite (CTA-NCC/GO) towards nickel ion. The formation of CTA-NCC/GO nanocomposite has been confirmed by FT-IR. The SPR analysis result shows that the CTA-NCC/GO has high binding affinity towards Ni〈sup〉2+〈/sup〉 from 0.01 until 0.1 ppm with binding affinity constant of 1.620 × 10〈sup〉3〈/sup〉 M〈sup〉−1〈/sup〉. The sensitivity for the CTA-NCC/GO calculated was 1.509° ppm〈sup〉−1〈/sup〉. The full width at half maximum (FWHM), data accuracy (DA), and signal-to-noise ratio (SNR) have also been determined using the obtained SPR curve. For the FWHM, the value was 2.25° at 0.01 until 0.08 ppm and decreases to 2.12° at 0.1 until 10 ppm. The DA for the SPR curves is the highest at 0.01 until 0.08 ppm and lowest at 0.1 until 10 ppm. The SNR curves mirrors the curves of SPR angle shift where the SNR increases with the Ni〈sup〉2+〈/sup〉 concentrations. For the selectivity test, the CTA-NCC/GO has the abilities to differentiate Ni〈sup〉2+〈/sup〉 in the mixture of metal ions.〈/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-S1386142518311016-ga1.jpg" width="266" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Chen Ma, Minrui Ma, Yida Zhang, Xinyue Zhu, Lin Zhou, Ran Fang, Xiaoyan Liu, Haixia Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉It is found that hypobromous acid (HOBr) can affect the activity of type IV collagen. Herein, we synthesized a lysosome-targeted fluorescence probe 〈strong〉NA-lyso〈/strong〉 based on Suzuki coupling reaction with naphthalimide as a fluorescent group. HOBr can oxidize the amino group and methylthio group, which increased the degree of conjugation of the probe, thereby affecting its optical properties. Accordingly, it can establish a method for the specific detection of HOBr. 〈strong〉NA-lyso〈/strong〉 has the properties including fast response, high fluorescence quantum yield (Φ = 59.17%), high selectivity, low cytotoxicity and good membrane-permeability. The probe can locate to lysosome of cells. The potential of the probe as biosensor for HOBr was demonstrated by imaging of exogenous and endogenous HOBr in living cells and in mice. In consequence, 〈strong〉NA-lyso〈/strong〉 is expected to be a powerful tool to detect HOBr in complex biosystem and provides a means of exploring physiological functions associated with HOBr in living organisms.〈/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-S1386142518310990-ga1.jpg" width="332" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 17 February 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering〈/p〉 〈p〉Author(s): M. Abdullah Sandıkkaya, Sinan Akkar, Pierre-Yves Bard〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We introduce a site factor computation method for a region by extending the site-specific and probabilistic site amplification approach in Bazzuro and Cornell (2004). The site-factor exceedance probability is estimated from the exceedance probabilities of the reference rock ground motion and the soil amplification conditioned on the reference rock ground motion. The former probability is represented by regional hazard curves. The latter probability is computed from soil amplification models. The proposed method is capable of yielding site factors for a target exceedance probability. This property does not exist in the current code-based site factors. Given a site class, if the site factors and the reference rock spectrum possess the same exceedance probability the resulting spectrum would have the same probability of exceedance. The use of such probabilistically consistent earthquake demands would be more relevant for probability-based seismic design and assessment. Owing to the use of hazard curves, the proposed method can account for regional seismicity in the computation of site factors.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 17 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering〈/p〉 〈p〉Author(s): Jorge Ruiz-García〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A discussion on the paper by Ji et al. [1] is presented. The paper is focused on the evaluation of residual displacement ratios, named 〈em〉C〈/em〉〈sub〉〈em〉r〈/em〉〈/sub〉, of single-degree-of-freedom (SDOF) systems subjected to a set of 120 earthquake ground motions recorded at site class E according to the FEMA 450 [2] document published in the United States. Based on their results, the authors introduced a predictive equation to obtain estimates of mean 〈em〉C〈/em〉〈sub〉〈em〉r〈/em〉〈/sub〉. This paper discusses its main results and the proposed equation in the light of previous published research on the subject.〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 118〈/p〉 〈p〉Author(s): S. Soltanieh, M.M. Memarpour, F. Kilanehei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Highway bridges with piers of unequal height crossing irregular topographical surfaces have potential complexities in terms of component vulnerability evaluations. This paper investigates the seismic behavior of a five-span concrete girder bridge with three coefficients of pier height and two different types of irregular configurations. Moreover, soil-structure interaction is taken into account by modeling a typical deep foundation, including piles and the surrounding soil, in order to examine the effect of pier base flexibility compared to the equivalent fixed-base model. For this purpose, incremental dynamic analyses are performed on the three-dimensional analytical finite element models using a set of ground motion pairs each rotated about the vertical axis of bridge producing seven angles of seismic incidence. The results obtained from the dynamic analyses and fragility assessment of the selected bridge models illustrate that substructure irregularity, support condition of piers, and directionality of seismic excitations are three interdependent factors in vulnerability assessment of highway bridges. Variation in each of the above-mentioned factors leads to change in the fragility characteristics of a bridge at global system failure mode or individual component limit states.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Zohreh Alyaninezhad, Ahmadreza Bekhradnia, Nourollah Feizi, Sattar Arshadi, Mahmood Zibandeh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A practical and an efficient Schiff base fluorescent chemosensor, salicylidene-4-aminoantipyrinyl-4-aminophenol (〈strong〉A2〈/strong〉) has been synthesized through the condensation procedure of 1-phenyl-2,3-dimethyl-4-(N-2-hydroxybenzylidene)-3-pyrazoline-5-one and 4-aminophenol. Compound 〈strong〉A2〈/strong〉 has displayed a considerable fluorescence enhancement with high selectivity and sensitivity toward Al〈sup〉3+〈/sup〉 ion and exhibited an emission band at 484 nm, which contained a low detection limit (LOD) of 1.06 × 10〈sup〉−7〈/sup〉 M. In accordance to the experimental study, DFT, TDDFT calculations, and the enhancement of fluorescence intensity might be attributed to the inhibition of Photoinduced Electron Transfer (PET) along with the Excited-State Intramolecular Proton Transfer (ESIPT). As it has been specified by Job's plot and DFT calculations, the binding stoichiometries of 〈strong〉A2〈/strong〉 with Al〈sup〉3+〈/sup〉 are 1:1, while the association constant (Ka) of Al〈sup〉3+〈/sup〉 has been calculated and observed to be 2.67 × × 10〈sup〉5〈/sup〉 M〈sup〉−1〈/sup〉. Furthermore, the binding behavior and sensing mechanism of 〈strong〉A2〈/strong〉 with Al〈sup〉3+〈/sup〉 have been confirmed through the experiments of 〈sup〉1〈/sup〉H NMR titration.〈/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-S1386142518311053-ga1.jpg" width="273" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Xiong-jie Zhao, Yu-ren Jiang, Yu-ting Li, Bing-qing Yang, Ce Liu, Zhi-hong Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrogen sulfide (H〈sub〉2〈/sub〉S) has been regarded as an important gas transmitter playing vital role in cytoprotective processes and redox signaling. It is very meaningful to monitor and analyze it in biosystem for obtaining important physiological and pathological information. Despite numerous fluorescent probes for cellular H〈sub〉2〈/sub〉S have been reported in past decades, only a few have capability to detect mitochondrial H〈sub〉2〈/sub〉S with near-infrared (NIR) emission. Therefore, a new mitochondria-targeting NIR fluorescent probe (〈strong〉Mito〈/strong〉-〈strong〉NSH〈/strong〉) for detection of cellular H〈sub〉2〈/sub〉S was developed by introducing 2,4-dinitrophenyl ether into a novel dye (〈strong〉Mito〈/strong〉-〈strong〉NOH〈/strong〉). A large “turn-on” NIR fluorescence response was obtained due to thiolysis of ether to hydroxyl group when 〈strong〉Mito〈/strong〉-〈strong〉NSH〈/strong〉 was treated with NaHS. Moreover, 〈strong〉Mito〈/strong〉-〈strong〉NSH〈/strong〉 could quantitatively detect H〈sub〉2〈/sub〉S at concentration ranging from 0 to 30 μM with a detection limit of 68.2 nM, and it exerts some superior optical properties, such as large stokes shift (107 nm), highly selectively mitochondria location, fast response and high selectivity to H〈sub〉2〈/sub〉S. More impressively, it was successfully applied to imaging exogenous and endogenously generated H〈sub〉2〈/sub〉S in living HeLa cells 〈em〉via〈/em〉 confocal fluorescence microscopy.〈/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-S1386142518311168-ga1.jpg" width="379" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Yuan Wang, Hao Wu, Wei-Na Wu, Xian-Jie Mao, Xiao-Lei Zhao, Zhou-Qing Xu, Zhi-Hong Xu, Yun-Chang Fan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A rhodamine hydrazone 〈strong〉1〈/strong〉 bearing coumarin moiety was designed and prepared. Compound 〈strong〉1〈/strong〉 exhibited high selectivity toward Co〈sup〉2+〈/sup〉 and trivalent metal ions with fluorescence enhancement in CH〈sub〉3〈/sub〉OH solution. However, 〈strong〉1〈/strong〉 selectively responded to Al〈sup〉3+〈/sup〉 in nearly pure H〈sub〉2〈/sub〉O media and was further applied to monitor Al〈sup〉3+〈/sup〉 in live cells. Moreover, 〈strong〉1〈/strong〉 could also act as a colorimetric probe toward Cu〈sup〉2+〈/sup〉 in either CH〈sub〉3〈/sub〉OH or H〈sub〉2〈/sub〉O solution. In addition, sensor 〈strong〉1〈/strong〉 displayed aggregation-induced ratiometric emission (AIRE) activities in mixed H〈sub〉2〈/sub〉O/CH〈sub〉3〈/sub〉OH solution.〈/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-S1386142518310801-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Bao-Li Wang, Dong-Qi Pan, Kai-Li Zhou, Yan-Yue Lou, Jie-Hua Shi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Benazepril, a common ACE inhibitor, widely used in the treatment of arterial hypertension and congestive heart failure. In this study, We evaluated the characteristics of the interaction between benazepril and BSA under the simulated physiological condition (pH 7.4) through various spectroscopic and molecular docking methods. Fluorescence and absorption spectroscopy results showed benazepril quenched the intrinsic fluorescence of BSA through a combined dynamic and static quenching mechanism. The number of binding sites (〈em〉n〈/em〉) and the binding constant (〈em〉K〈/em〉〈sub〉b〈/sub〉) of benazepril–BSA complex were circa 1 and 6.81 × 10〈sup〉3〈/sup〉 M〈sup〉−1〈/sup〉 at 298 K, respectively, indicating that the binding affinity between benazepril and BSA was moderate. The displacement experiments confirmed that benazepril binding to the site I of BSA, which was quite in accordance with molecular docking. The values of the Gibbs free energy (ΔG〈sup〉0〈/sup〉), enthalpic change (ΔH〈sup〉0〈/sup〉) and entropic change (ΔS〈sup〉0〈/sup〉) were negative, verifying that van der Waals force and hydrogen bonding interaction played a predominant roles in the process of spontaneous bonding. Furthermore, a slight change of the conformation in BSA upon benazepril interaction was proved through SF, 3-DF and FTIR spectroscopy results.〈/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-S1386142518311107-ga1.jpg" width="427" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Yan Zhuang, Kang-Yu Wang, Hua-Xiang Li, Meng Wang, Liang Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Shakedown analysis is a robust approach to solve the strength problem of a structure under cyclic or repeated loading, e.g. railway structure subjects to rolling and sliding loads. A three-dimensional analytical shakedown solution is developed in this paper for the strength analysis of cohesive-frictional materials under multiple Hertz loads, which is then applied into the shakedown analysis of railway structure. Different to the pavement, the railway structure subjects to multiple wheel loads acting on the surface of two parallel rails, and then transformed to the substructure, which leads to different elastic and residual stress fields. For the application of Melan's shakedown theorem, the residual stress field in railway strucuture is rationally simplified to find the most critical plane that influence the most on the shakedown limit. The elastic stresses is then analytically derived for a single layer half-space under multiple Hertz loads, and is obtained numerically by means of the finite element technique for the multi-layered railway structure. Finally, the shakedown limit can be obtained in a direct way. Parametric study indicates how wheel loads, material properties such as frictional coefficient, friction angle and Poisson's ratio, and multi-layers influence the shakedown limit and stability condition of railway structure. It is found that the shakedown load increases with the increase of cohesion ratio, ballast frictional angle, and thickness ratio. However, the increase of the shakedown load ceases once the failure location moves from ballast layers to sub-ballast layers. This indicates that there is an optimum combination of material properties and layer thickness which provides the maximum resistance to the train loads. The obtained results give a useful reference for the engineering design of the railway structure.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Lais Bukman, Camila Fabiano de Freitas, Wilker Caetano, Nádia Regina Camargo Fernandes, Noboru Hioka, Vagner Roberto Batistela〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉It is proposed a new approach to evaluate the performance of ultraviolet photoreactions by integrating UV-LED and a UV–Vis cuvette as a mini-reactor for kinetic monitoring in a spectrophotometer not influenced by external light. This system uses only 3.0 mL of solutions in a rectangular quartz cuvette with a mini-bar magnetic stirrer in a cell holder and a UV-LED of 5 W with λ〈sub〉max〈/sub〉 at 370 nm was positioned on the top of the cuvette and maintained at 25.0 〈sup〉o〈/sup〉C. The effectiveness of this photoreactor was demonstrated by measuring the real-time degradation of two model compounds, salicylic acid and methylene blue, in homogeneous and heterogenous systems. Photolysis of MB with H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 results in increasing of rate constants as [H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉] increased. Heterogeneous photocatalysis of MB and SA was fastest achieved in ZnO dosage of 0,20 g.L〈sup〉–1〈/sup〉. This mini-photoreactor allows monitoring the real-time kinetic performance collecting almost a thousand points in each experiment, leading to accurate rate constants. Moreover, this system presented positive environmental aspects such as: lower reactants and catalyst amounts, lower cost and waste amounts, use of the UV-LED radiation and labor time saving. This is a novel approach to determine the photoreaction effectiveness and it can be applied to systematic studies especially for the kinetic parameter determinations.〈/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-S138614251831103X-ga1.jpg" width="437" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Xu Tang, Zhi Zhu, Renjie Liu, Liang Ni, Yue Qiu, Juan Han, Yun Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel fluorescence probe L2 based on coumarin has been designed and synthesized. The probe L2 can be used for relay recognition of metal ions Al〈sup〉3+〈/sup〉 and anion F〈sup〉−〈/sup〉 in the aqueous HEPES buffer (0.05 M, pH = 7.4), and build a OFF-ON-OFF detection system. The probe showed high selectivity and sensitivity to target ions in the process of relay recognition, and the corresponding detection limit could be as low as 0.014 μM (Al〈sup〉3+〈/sup〉) and 0.03 μM (F〈sup〉−〈/sup〉). Besides, the geometry optimizations of probe L2 and [L2 + Al〈sup〉3+〈/sup〉] complex were carried out using the Gaussian 16 program based on DFT, and the identification mechanism of the probe was also discussed by the mass spectrometry and theoretical calculations. Moreover, the probe has also been successfully applied to detection of target ions in living cells.〈/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-S1386142518310849-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Jianting Yang, Jie Chai, Binsheng Yang, Bin Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aggregation-induced emission (AIE) luminogens are now showing strong potential in mimicking the energy donor of fluorescence resonance energy transfer (FRET) system. Herein, one highly efficient FRET system 〈strong〉1〈/strong〉-NiR is successfully fabricated in aqueous solution based on an AIE active compound 〈strong〉1〈/strong〉 and fluorescence dyes (Nile red (NiR)). 〈strong〉1〈/strong〉 acts as the energy donor and NiR acts as the acceptor in the FRET system with the optimum concentrations ratio [〈strong〉1〈/strong〉]/[NiR] = 100. Besides, the AIE(〈strong〉1)〈/strong〉 itself displays excellent selectivity for Cu〈sup〉2+〈/sup〉 ions at 525 nm with the detection limit of 1.32 × 10〈sup〉−7〈/sup〉 M. While through the FRET system of 〈strong〉1〈/strong〉-NiR system, the detection limit of Cu〈sup〉2+〈/sup〉 can be further decreased to 9.12 nM by monitoring the fluorescence at 630 nm. As a result, using an AIE probe to detect Cu〈sup〉2+〈/sup〉 based on FRET mechanism is a promising strategy.〈/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-S1386142518310837-ga1.jpg" width="423" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Emilio Meaurio, Eva Sanchez-Rexach, Amaia Butron, Jose-Ramon Sarasua〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The conformational behavior of chloramphenicol (CHL) in the solid, liquid and vapor phases is revisited here by means of FTIR spectroscopy and QM methods. In the crystalline phase, both the IR analysis and QM computations discard the conformer proposed by Acharya et al. (〈em〉Acta Cryst.,〈/em〉 1979, B35:1360–1363) and support the one proposed by Chatterjee et al. (〈em〉J. Cryst. Mol. Struct.,〈/em〉 1979, 9:295–304), characterized by an intramolecular O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H⋯O hydrogen bond in which the primary hydroxyl group acts as hydrogen bond donor. The conformational behavior of CHL in the liquid and gas phases has been analyzed using QM calculations. The Self-Consistent Reaction Field (SCRF) method with the Onsager solvation model has been used for the initial optimizations in solution, and the lowest energy conformers have been refined using the Solvation Model based on Density (SMD). In solution environment the intramolecular O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H⋯O hydrogen bond in CHL is reversed so that the secondary hydroxyl group acts as hydrogen bond donor. In addition, the dichloroacetamide group folds back further over the phenyl ring to form an intramolecular C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Cl⋯π halogen bond. Two different halogen bonds are actually observed (each one with a different chlorine atom) resulting in two different stable conformers, that can be detected by FTIR spectroscopy due to the conformational sensitivity of the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O group to the conformation of the dichloroacetyl group. Finally, the stability of the conformers with the polarity of the medium is also discussed.〈/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-S1386142518310795-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Tao Jia, Zhi-Hang Chen, Peng Guo, Junping Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two cationic δ,δ′‑diazacarbazoles, 1‑Methyl‑5〈em〉H〈/em〉‑pyrrolo[3,2‑〈em〉b〈/em〉:4,5‑〈em〉b〈/em〉′]dipyridinium iodide (〈strong〉MPDPI〈/strong〉) and 1,5‑Dimethyl‑5〈em〉H〈/em〉‑pyrrolo[3,2‑〈em〉b〈/em〉:4,5‑〈em〉b〈/em〉′]dipyridinium iodide (〈strong〉DPDPI)〈/strong〉, were devised and synthesized. Through characterizations of the interactions between DNA and the two δ,δ′‑diazacarbazoles by various spectroscopy means, the strong interactions between the two compounds and double-strand DNA have been observed and the interaction types and mechanisms were explored. UV–Vis and fluorescent data have shown the big changes of DNA in the presence of either of the two compounds, demonstrating that both of the δ,δ′‑diazacarbazoles can bind to DNA tightly, and high ionic strength decreased the intercalative interactions. The UV–Vis and fluorescence of dsDNA in the presence of 〈strong〉DPDPI〈/strong〉 showed more profound changes than those in the presence of 〈strong〉MPDPI〈/strong〉, due to 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉CH〈sub〉3〈/sub〉 (in the structure of 〈strong〉DPDPI〈/strong〉) taking place of H (in the structure of 〈strong〉MPDPI〈/strong〉) at the position of 5‑NH. And the circular dichroism (CD) spectra of CT-DNA and atomic force microscopy (AFM) results indicated more compacted conformation of DNA in the presence of 〈strong〉DPDPI〈/strong〉 than 〈strong〉MPDPI〈/strong〉, implying that 〈strong〉DPDPI〈/strong〉 has a more significant effect on DNA conformations than 〈strong〉MPDPI〈/strong〉. Most interestingly, fluorescence enhancement of cationic δ,δ′‑diazacarbazoles occurred in the presence of DNA. With ionic strength increasing, the intercalative interactions between δ,δ′‑diazacarbazoles and DNA were weakened, but δ,δ′‑diazacarbazoles-DNA complexes showed enhanced fluorescence, which indicated that there are other interactions present at high ionic strength. Furthermore, laser confocal fluorescence microscopy results proved that 〈strong〉DPDPI〈/strong〉 was membrane-permeable and stained living cells.〈/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-S1386142518310758-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Hamideh Elmizadeh, Majid Soleimani, Farnoush Faridbod, GhasemRezanejade Bardajee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, CdTe QDs were prepared in aqueous medium and then capped with a synthetic heterocycle ligand (CdTe/L QDs) via surface modification method. Characterization of synthesized CdTe/L QDs was carried out through various analytical techniques including fluorescence spectroscopy, transmission electron microscopy (TEM), UV–Vis spectrophotometry, thermo-gravimetric (TG) analysis and Fourier transform infrared (FTIR). The fluorescence intensity of the CdTe/L QDs at 520 nm (excitation at 380 nm) was selectively quenched in the presence of trace amounts of silver ions. CdTe/L QDs were utilized as an ultrasensitive and selective fluorescent sensor for determination of trace concentrations of silver ions with a detection limit of 6.12 ± 0.11 × 10〈sup〉−10〈/sup〉 mol L〈sup〉−1〈/sup〉 and a linear range of 2.04 ± 0.10 × 10〈sup〉−9〈/sup〉 mol L〈sup〉−1〈/sup〉–3.63 ± 0.12 × 10〈sup〉−7〈/sup〉 mol L〈sup〉−1〈/sup〉. The fabricated optical sensor was also used for the measurement of silver ions in real water samples which yielded satisfactory analytical results. These results were also evaluated with inductively coupled plasma emission spectroscopy (ICP-OES). This study shows that CdTe/L QDs could have potential applications in selective and sensitive analysis of different water samples for detection of silver ions.〈/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-S1386142518310783-ga1.jpg" width="297" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Fei Guo, Clemens M. Altaner〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Deuterium exchange combined with near infrared (NIR) spectroscopy was used to study the roles of accessible and inaccessible cellulose in the load transfer of eucalyptus wood. Monitoring the drying process helped to assign NIR bands of deuterated wood samples. Polarized NIR spectra of protonated and deuterated samples confirmed that inaccessible hydroxyl groups in eucalyptus wood were preferably oriented in the longitudinal direction. The spectral changes on NIR spectra caused by mechanical strain could be highlighted by averaging loading and unloading cycles to compensate for effects of desorption and isotope re-exchange due to environmental fluctuations. After deuteration, the bands affected by mechanical strain at around 6420, 6240 and 4670 cm〈sup〉−1〈/sup〉, which had been assigned to hydroxyl groups in cellulose, remained at these positions, suggesting the inaccessible cellulose fraction was the main load-bearing component in wood. A small band at around 4700 cm〈sup〉−1〈/sup〉 responding to mechanical strain, becoming visible in the deuterated spectra, indicated that accessible hydroxyls also contributed to the load transfer. Furthermore, the measurements confirmed previous reports of moisture adsorption of wood under tensile stress.〈/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-S1386142518310746-ga1.jpg" width="352" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): K.S. Rao, D. Ganesh, F. Yehya, A.K. Chaudhary〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The paper reports the potential use of UV based pulsed photoacoustic spectroscopy to study the thermal stability of some well-known premier explosives such as TNT, RDX, CL20, and ANTA between 30 and 350 °C range. The thermal PA spectra of samples were recorded using fourth harmonic wavelength i.e. 266 nm of pulse duration 7 ns and repetition rate 10 Hz obtained from Q-switched Nd: YAG laser system. Under the influence of UV radiation, the explosive molecules in vapor phase follow the photodissociation process and converted into their byproducts such as NO, NO〈sub〉2〈/sub〉 and N〈sub〉2〈/sub〉O etc. due to π* ← 〈em〉n〈/em〉 transitions, which are responsible for the generation resultant PA signal at 266 nm wavelength. The results obtained from PA spectra as a function of temperature are cross verified with Thermo gravimetric-differential thermal analysis (TG-DTA) to ascertain the thermal stability of these samples. The comparative PA spectra of samples were analyzed and shown the behavior of acoustic modes with respect to incident laser energy, and data acquisition time. Finally, the thermal quality factor “Q” is measured to test the stability of reported explosives.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310734-ga1.jpg" width="237" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Sayed M. Saleh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This novel work presents a promising application to use Zinc oxide nanospheres as nanocatalysts in photocatalytic degradation of methyl orange dye. The hydrothermal route was utilized in the synthesis process of ZnO nanospheres. The size of the synthesized ZnO nanoparticles is around 200–250 nm diameter. The synthesized nano-oxides were characterized utilizing several instruments such as X-ray diffraction, Brunauer, Emmett, and Teller (BET), and scanning electron microscope (SEM). The resulting nanoparticles are utilized as an efficient tool for degradation of methyl orange (MO) dye under UV radiation. Essential parameters were studied on degradation process involving the initial concentration of MO, pH, stirring the solution, dose of the ZnO nanospheres, the oxygen content of the solution, calcination of the nanomaterials. All activity experiments under UV radiation provide excellent results for the degradation process of MO. Also, the recovery of ZnO nanomaterials was investigated based on the photocatalytic process efficiency. The results show the high possibility of reuse ZnO nanospheres for several photocatalytic processes. Also, the nanocatalysts were applied for a real environmental sample with providing high photocatalytic 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-S138614251831062X-ga1.jpg" width="311" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): B.W. Maurer, R.A. Green, S. van Ballegooy, L. Wotherspoon〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Utilizing an unprecedented database of field and laboratory test data from Christchurch, New Zealand, this study develops deterministic and probabilistic correlations relating the soil behavior type index (〈em〉I〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉) to laboratory test-based liquefaction susceptibility and fines content. The proposed 〈em〉I〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉 correlations are in turn used to assess liquefaction hazard for 9623 case studies compiled from three earthquakes that impacted Christchurch, New Zealand, wherein the predicted liquefaction severity is compared to post-earthquake field observations. Furthermore, the accuracy of the predictions based on the region-specific 〈em〉I〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉 correlations are compared to those made using generic 〈em〉I〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉 correlations. The use of the Christchurch-specific 〈em〉I〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉 correlations, in general, only slightly improved the liquefaction severity predictions. These findings could be a result of shortcomings in the procedures used to predict liquefaction triggering and/or liquefaction manifestations. Nevertheless, the findings give credence to the use of generic correlations for typical projects. Finally, the overall framework of the study used herein can be applied to worldwide locals and is not just limited for use in the Canterbury region of New Zealand.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): George Papathanassiou, Sotiris Valkaniotis, Spyros Pavlides〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The earthquake Mw6.6 (macroseismic intensity VIII, ESI-07 scale) that occurred on July 20, 2017 at 22:31 UTC (01:31 local time) in Gökova Bay, SE Aegean Sea, induced minor damages to contemporary structures at the island of Kos, Greece, while severe damages were reported on Venetian and Ottoman-era constructions, causing two deaths. Focusing on the island of Kos, secondary effects were reported in the eastern part, including liquefaction-related phenomena and tsunami. The generation of the latter one indicates the likelihood to this type of effects in the Aegean Sea. Liquefaction-induced lateral spreading caused severe structural damages at the waterfront area of the city of Kos. This area was investigated in detail few days after the event, by performing field measurements using a surveyor's tape and additionally, by applying SfM-based technique using a ground-based digital camera. The values of horizontal deformation, measured by these two techniques are in agreement, while on vertical axis a deviation of 12% is resulted.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): D. Farahani, F. Behnamfar, H. Sayyadpour, M. Ghandil〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The problem of seismic impact between torsionally coupled multi story moment frame buildings is investigated in this paper. Five pairs of adjacent structures spaced at various separation distances are considered. The buildings are 4–10 stories in height. Although a common plan being symmetric with regard to lateral stiffness is considered, a mass eccentricity variable from zero to 30% of the plan dimension is assumed. By three-dimensional modeling of the nonlinear torsional buildings having common story elevations, the seismic pounding happen anywhere along the adjacent buildings edges. Effect of impact and torsional eccentricity are studied by comparison of nonlinear dynamic responses of buildings at different clear distances under 11 consistent earthquakes. The responses include pounding forces at stories, story drifts, story shears and plastic hinge rotations. It is shown that how pounding incidents increase for larger eccentricities and how pounding occurs even at the clear distances prescribed by seismic design codes. The combined effect of torsional eccentricity and pounding results in amplifying the nonlinear response of structure especially for the peripheral frames.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): Miad Saberi, Charles-Darwin Annan, Jean-Marie Konrad〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, an implementation of an advanced two-surface plasticity interface constitutive model in a general-purpose finite element code ABAQUS for application in soil-structure interaction problems under static and dynamic loading conditions is presented. A recently developed constitutive model by the authors for gravelly soil-structure interface was improved to simulate the behavior of both gravelly and sandy soil-structure interfaces. A new failure surface was introduced into the model in order to simulate the softening behavior of interfaces under monotonic and cyclic loading. The constitutive model was then implemented in ABAQUS as a thin-layer interface element to demonstrate its capabilities in representing the complex behavior under different stress paths and normal stresses, including debonding and rebonding mechanisms at interface zones. The accuracy and robustness of the numerical implementation algorithm was examined by considering the effect of time step size, and by simulating different boundary value problems. The numerical predictions under different loading and boundary conditions were compared with experimental observations.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): Hongjing Li, Michael J. O’Rourke〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉It is recognized that seismic damages to segmented buried pipelines depend in part upon transient ground strain due to seismic wave propagation. Such wave propagation damage seems to be larger at sites with variable subsurface conditions, because of drastic changes in seismic wave characteristics as they propagates in heterogeneous rock and soil layers. This paper intends to investigate the amplification of horizontal ground strains in a valley subjected to vertically incident SH waves. A 2D model with an inclined soil-rock interface is established to simulate conditions of the valley subject to seismic wave propagation. A procedure for evaluating the ground strain amplification is developed by consideration of travel path effects. Three amplification/de-amplification mechanisms are specifically considered, the ground velocity amplification, ground strain amplification due to the change in the propagation direction, and de-amplification due to a lack of total reflection at the soil-rock interface. The analysis results show that the maximum amplification factor is mainly affected by the interface inclination angle and shear wave velocity ratio between the valley soil and the base rock. For a given number of wave cycles, the amplification factor grows with the increment of the inclination angle and declines with the growth of shear wave velocity ratio. The de-amplification at inclined interface is likely to nullify the amplification generated by travel path effects.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Shiping Zhang, Chunyi Cui, Gang Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper we develop a simplified analytical solution for the impedance function of viscoelastic pile groups partially embedded in a layered, transversely isotropic, liquid-saturated, viscoelastic soil medium under a vertical time-harmonic load. In developing our solution, we use the porous medium model established by de Boer to describe the soil and the Rayleigh–Love rod model to describe the pile groups. To obtain the vertical impedance function of the pile groups, based on a “two pile model” consisting of an active pile and a passive pile, we first get a displacement attenuation function and shearing forces to piles of the soil by using a separation method of variables to solve motion equations for the soil. Second, using this displacement attenuation function and shearing forces, we derive a dynamic interaction factor of pile to pile. Then, by means of the dynamic interaction factor and a superposition principle, we obtain the vertical impedance function of the pile groups. We validate our model by comparing it to the reported results of purely elastic soils. Finally, we conduct numerical examples obtained from our model to show the effects of main parameters, such as the non-embedded length of piles, the transversely isotropic parameter of soils, and the liquid–solid coupled coefficient of soils on the vibration characteristics of a typical pile group. From these analyses, we conclude that the dynamic interaction factors of pile to pile for single-phase soils suggested by Dobry and Gazetas are not suitable for the vibration problems of pile groups in saturated soils. Thus, it is necessary to present corresponding dynamic pile–pile interaction factors for such problems. Moreover, the non-embedded length of piles, the transversely isotropic parameter of soils, and the liquid–solid coupled coefficient of soils have noticeable effects on the dynamic impedance of pile groups, which is valuable for pile foundation designs.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): Lisa M. Star, Salih Tileylioglu, Michael J. Givens, George Mylonakis, Jonathan P. Stewart〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We describe procedures to evaluate the dynamic properties of test structures subject to forced vibration testing. We seek modal vibration periods and damping ratios corresponding to the actual flexible-based response of the structure (incorporating the effects of compliance in the soil medium supporting the foundation) and similar attributes for a fixed-base condition in which only the flexibility of the structure is represented. Our approach consists of using suitable input and output time series with conventional parametric system identification procedures, and as such extends previously developed procedures for use with earthquake recordings. We verify the proposed approach and demonstrate its application using data from two test structures supported on shallow foundations that have been used in forced vibration tests and that have recorded earthquakes. The structures were tested with and without braces to modify their stiffness and were deployed at two sites with different soil conditions. We analyze the results to evaluate experimental period lengthening ratios and foundation damping. The results show (1) strong increases in period lengthening and foundation damping with the wave parameter (dimensionless ratio of structure-to-soil stiffness), (2) compatibility between modal properties from forced vibration testing and earthquake excitation, (3) soil nonlinearity increases period lengthening and modifies foundation damping in a manner that can be reasonably captured in predictive models using equivalent-linear soil properties compatible with a proposed shear strain index.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): Seokho Jeong, Domniki Asimaki, Jacob Dafni, Joseph Wartman〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Topographic effects, the modification of seismic shaking by irregular topographies compared to flat ground, have been extensively studied. Very few studies, however, have investigated the effects of the stratigraphy and nonlinear response of the underlying geology on topographic amplification. Furthermore, most experimental studies have been performed in the field, where it is often difficult to establish an ideal flat-ground reference station, as well as to characterize the soil properties and their spatial variability in sufficient detail. Dafni [1] recently tested the seismic response of step-like slopes in a series of centrifuge experiments, where the incident motion, reference station and material properties were characterized in detail. In this study, we investigated the influence of the container boundary on topographic effects observed in the centrifuge experiments by performing numerical simulations with and without the container boundary. Our analysis suggested that the rigid-body rocking motion of the centrifuge container likely increased the experimental topographic spectral ratios, contributing to the discrepancy between the simulated and observed spectral ratios. We also found that although the laminar box lateral boundaries caused spurious reflections, they didn't qualitatively affect the ground surface amplification pattern compared to numerical predictions of the same configuration without boundaries. At the same time, and most importantly, however, we found that the baseplate –by trapping waves scattered and diffracted by the slope– amplified the ground motion at the crest up to one order of magnitude compared to numerical predictions of the response in absence of the baseplate. Our results show that topographic effects can be significantly affected by the underlying soil stratigraphy, and allude to the potentially significant role of this phenomenon in elevating seismic risk in regions with strong topographic relief. The findings of this study also suggest that future studies will benefit from clear understanding and careful considerations of capabilities and limitations of different investigation methods and that the numerical modeling and the lab testing (or the field testing) methods should complement each other.〈/p〉〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 117〈/p〉 〈p〉Author(s): Dan Huang, Shuo Cui, Xiaoqing Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Using drilling and blasting method to construct the Mountain tunnel, it is important to monitoring and analysis of blasting seismic wave. The research of simple characteristics of blasting vibration wave such as amplitude, frequency, duration in the previous study, it is lack the detailed characteristics of blasting seismic waves such as frequency distribution characteristics of blasting seismic wave, blasting energy distribution. Thus, Fourier transform and wavelet packet transform are both used to analysis the time - frequency characteristics of measured vibration signal, and the characteristics of its multi-frequency band and energy distribution are discussed. The blasting vibration with the blasting charge of 79.2 kg are did, and the wave are received distance blast source 10 m, 25 m, 40 m. The maximum three vector resultant velocity at 10 m is 5.84 cm/s, which meets the specification safety requirement. Analysis of blasting vibration signals of vertical axis which distance blast source 10 m, the main frequency of this signal is 101.9 Hz, and the relative amplitude is 2382 use by Fourier transform. The Wavelet packet analysis show that, blasting vibration signal has obvious energy distribution characteristics of multi-frequency band. The dominant frequency band (31.25 Hz~125.00 Hz) contains more than 70% of the energy of vibration signal.〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 116〈/p〉 〈p〉Author(s): Nathalie Glinsky, Etienne Bertrand, Julie Régnier〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A two-year seismological experiment in Rognes (South Eastern France) confirms the site effects responsible for the severe damage experienced during the 1909 Provence earthquake. Many experimental and numerical studies have been dedicated to quantify and understand the effect of topography on seismic ground motion. However, these local amplifications depend on many parameters and their causes are not yet fully known. Numerical simulation is an interesting tool to try to explain these phenomena and simplified models are helpful for parametric analysis. For this, we use a discontinuous Galerkin finite element method to study the amplification along 2D profiles. First, an extensive numerical study considering an idealized hill topography investigates the combined effects of the steepness, heterogeneity and the angle of incidence on the surface response and focuses in particular on strong amplifications recorded in gentle slope configurations. Secondly, simulations are applied to a realistic 2D profile of the Rognes area. The confrontation of these numerical results with data from a seismological survey help to confirm the influence of both the topography and in-depth geology.〈/p〉〈/div〉