bluuebunny/crossref_metadata_2025 huggingface dataset:
Ordered heterogeneity of molecular photosensitizer toward enhanced photocatalysis
Authors: Zhang Ji-Hong , Gong Yun-Nan , Wang Hong-Juan , Wang Yu-Chen , Yang Wei , Mei Jian-Hua , Zhong Di-Chang , Lu Tong-Bu
Published: March 2022

Significance

The photosensitizer is one of the important components in the photocatalytic system. Molecular photosensitizers have well-defined structures, which is beneficial in revealing the catalysis mechanism and helpful for further structural design and performance optimization. However, separation and recycling of the molecular photosensitizers is a great problem. Loading them into/on two/three-dimensional supports through covalent bonds, electrostatic interactions, and supramolecular interactions is a method that enhances their separation and recycling capability. Nonetheless, the structures of the resulting composites are unclear. Thus, the development of highly crystalline heterogeneity methods for molecular photosensitizers, albeit greatly challenging, is meaningful and desirable in photocatalysis, through which heterogeneous photosensitizers with well-defined structures, definite catalysis mechanisms, and good catalytic performance would be expected.
Olfactory regulation by dopamine and DRD2 receptor in the nose
Authors: Zhou Hai-Qian , Zhuang Liu-Jing , Bao Hong-Qiang , Li Sheng-Ju , Dai Feng-Yan , Wang Ping , Li Qian , Yin Dong-Min
Published: March 2022

Significance

Despite the identification of neural circuits and circulating hormones in olfactory regulation, the peripheral targets for olfactory modulation remain relatively unexplored. Here we show that dopamine D2 receptor (DRD2) is expressed in the cilia and somata of mature olfactory sensory neurons (OSNs), while nasal dopamine (DA) is mainly released from the sympathetic nerve terminals, which innervate the mouse olfactory mucosa (OM). We further demonstrate that DA-DRD2 signaling in the nose plays important roles in regulating olfactory function using genetic and pharmacological approaches. Moreover, the local DA synthesis in mouse OM is reduced during hunger, which contributes to starvation-induced olfactory enhancement. Altogether, we demonstrate that nasal DA and DRD2 receptor can serve as the potential peripheral targets for olfactory modulation.
An operator-based expression toolkit for
Bacillus subtilis
enables fine-tuning of gene expression and biosynthetic pathway regulation
Authors: Fu Gang , Yue Jie , Li Dandan , Li Yixin , Lee Sang Yup , Zhang Dawei
Published: March 2022

Significance

A gene regulatory system is an important tool for the engineering of biosynthetic pathways of organisms. Here, we report the development of an inducible-ON/OFF regulatory system using a
malO
operator as a key element. We identified and modulated sequence, position, numbers, and spacing distance of
malO
operators, generating a series of activating or repressive promoters with tunable strength. The stringency and robustness are both guaranteed in this system, a maximal induction factor of 790-fold was achieved, and nine proteins from different organisms were expressed with high yields. This system can be utilized as a gene switch, promoter enhancer, or metabolic valve in synthetic biology applications. This operator-based engineering strategy can be employed for developing similar regulatory systems in different microorganisms.
Ferrous iron–activatable drug conjugate achieves potent MAPK blockade in KRAS-driven tumors
Authors: Jiang Honglin , Muir Ryan K. , Gonciarz Ryan L. , Olshen Adam B. , Yeh Iwei , Hann Byron C. , Zhao Ning , Wang Yung-hua , Behr Spencer C. , Korkola James E. , Evans Michael J. , Collisson Eric A. , Renslo Adam R.
Published: March 2022

KRAS mutations drive a quarter of cancer mortality, and most are undruggable. Several inhibitors of the MAPK pathway are FDA approved but poorly tolerated at the doses needed to adequately extinguish RAS/RAF/MAPK signaling in the tumor cell. We found that oncogenic KRAS signaling induced ferrous iron (Fe2+) accumulation early in and throughout mutant KRAS-mediated transformation. We converted an FDA-approved MEK inhibitor into a ferrous iron–activatable drug conjugate (FeADC) and achieved potent MAPK blockade in tumor cells while sparing normal tissues. This innovation allowed sustainable, effective treatment of tumor-bearing animals, with tumor-selective drug activation, producing superior systemic tolerability. Ferrous iron accumulation is an exploitable feature of KRAS transformation, and FeADCs hold promise for improving the treatment of KRAS-driven solid tumors.
DNA damage contributes to neurotoxic inflammation in Aicardi-Goutières syndrome astrocytes
Authors: Giordano Anna Maria Sole , Luciani Marco , Gatto Francesca , Abou Alezz Monah , Beghè Chiara , Della Volpe Lucrezia , Migliara Alessandro , Valsoni Sara , Genua Marco , Dzieciatkowska Monika , Frati Giacomo , Tahraoui-Bories Julie , Giliani Silvia Clara , Orcesi Simona , Fazzi Elisa , Ostuni Renato , D’Alessandro Angelo , Di Micco Raffaella , Merelli Ivan , Lombardo Angelo , Reijns Martin A.M. , Gromak Natalia , Gritti Angela , Kajaste-Rudnitski Anna
Published: March 2022

Aberrant induction of type I IFN is a hallmark of the inherited encephalopathy Aicardi-Goutières syndrome (AGS), but the mechanisms triggering disease in the human central nervous system (CNS) remain elusive. Here, we generated human models of AGS using genetically modified and patient-derived pluripotent stem cells harboring TREX1 or RNASEH2B loss-of-function alleles. Genome-wide transcriptomic analysis reveals that spontaneous proinflammatory activation in AGS astrocytes initiates signaling cascades impacting multiple CNS cell subsets analyzed at the single-cell level. We identify accumulating DNA damage, with elevated R-loop and micronuclei formation, as a driver of STING- and NLRP3-related inflammatory responses leading to the secretion of neurotoxic mediators. Importantly, pharmacological inhibition of proapoptotic or inflammatory cascades in AGS astrocytes prevents neurotoxicity without apparent impact on their increased type I IFN responses. Together, our work identifies DNA damage as a major driver of neurotoxic inflammation in AGS astrocytes, suggests a role for AGS gene products in R-loop homeostasis, and identifies common denominators of disease that can be targeted to prevent astrocyte-mediated neurotoxicity in AGS.
Exploring Fresnel diffraction at a straight edge with a neural network
Authors: Finot Christophe , Boscolo Sonia
Published: March 2022

We describe a research project carried out with a group of undergraduate physics students and aimed at exploring the use of a neural network to study a classical problem in wave optics whose analytical solution is well known: the diffraction of light by the straight edge of an opaque semi-infinite screen. Through this exposure to machine learning, the students were able to appreciate the basic steps involved in a machine-learning process.
Using quantum mechanics for calculation of different infinite sums
Authors: Mali Petar , Rutonjski Milica , Radošević Slobodan , Pantić Milan , Pavkov-Hrvojević Milica
Published: March 2022

We demonstrate that a certain class of infinite sums can be calculated analytically starting from a specific quantum mechanical problem and using principles of quantum mechanics. For simplicity we illustrate the method by exploring the problem of a particle in a box. Twofold calculation of the mean value of energy for the polynomial wave function inside the well yields even argument p (p > 2) of Riemann zeta and related functions. This method can be applied to a wide class of exactly solvable quantum mechanical problems which may lead to different infinite sums. Besides, the analysis performed here provides deeper understanding of superposition principle and presents useful exercise for physics students.
V-pits formation in InGaN/GaN: influence of threading dislocations and indium content
Authors: Stránská Matějová Jana , Hospodková Alice , Košutová Tereza , Hubáček Tomáš , Hývl Matěj , Holý Václav
Published: March 2022

Two sets of InGaN/GaN MOVPE-grown samples were studied by high-resolution x-ray diffraction techniques together with statistical analysis of atomic force microscope images in order to determine the impact of In concentration and threading dislocations (TDs) density on the V-pit formation. It was shown that in our samples, the density of V-pits in the epilayer matched the TD density with a screw component in the substrate. Pure edge TDs do not affect the V-pit density. The In concentration influences the size of the V-pits, but not their density.
Plasma diagnostics and modeling of lithium-containing plasmas
Authors: Ono Toshisato , Ganguly Shreyashi , Tu Qiaomiao , Kortshagen Uwe R , Aydil Eray S
Published: March 2022

Thin-film deposition from chemically reactive multi-component plasmas is complex, and the lack of electron collision cross-sections for even the most common metalorganic precursors and their fragments complicates their modeling based on fundamental plasma physics. This study focuses on understanding the plasma physics and chemistry in argon (Ar) plasmas containing lithium bis (trimethylsilyl) amide used to deposit Li
x
Si
y
thin films. These films are emerging as potential solid electrolytes for lithium-ion batteries, and the Li-to-Si ratio is a crucial parameter to enhance their ionic conductivity. We deposited Li
x
Si
y
films in an axial flow-through plasma reactor and studied the factors that determine the variation of the Li-to-Si ratio in films deposited at various points on a substrate spanning the entire reactor axis. While the Li-to-Si ratio is 1:2 in the precursor, the Li-to-Si ratio is as high as 3:1 in films deposited near the plasma entrance and decreases to 1:1 for films deposited downstream. Optical emission from the plasma is dominated by Li emission near the entrance, but Li emission disappears downstream, which we attribute to the complete consumption of the precursor. We hypothesized that the axially decreasing precursor concentration affects the electron energy distribution function in a way that causes different dissociation efficiencies for the production of Li and Si. We used Li line intensities to estimate the local precursor concentration and Ar line ratios to estimate the local reduced electric field to test this hypothesis. This analysis suggests that the mean electron energy increases along the reactor axis with decreasing precursor concentration. The decreasing Li-to-Si ratio with axially decreasing precursor concentration may be explained by Li release from the precursor having lower threshold energy than Si release.
Breakdown strength improvement of polypropylene by introducing long-chain branched structures for film capacitors
Authors: Xiao Meng , Zhang Mengdie , Du Boxue , Ran Zhaoyu , Liu Haoliang , Qin Yawei
Published: March 2022

The breakdown strength of polypropylene (PP) for film capacitors drops sharply in a high-temperature environment, which would lead to capacitor insulation failure frequently. This paper proposes a method to improve the breakdown strength of PP at high temperatures by introducing long-chain branches (LCBs). Different from traditional linear PP, the results show that LCBs can increase the number of spherulites and refine the grains due to heterogeneous nucleation, resulting in a reduction in weak areas in the films and an increase in trap densities and energy levels in long-chain branched polypropylene (LCBPP). In addition, the higher melt strength of LCBPP indicates that LCBs promote entanglement between molecular chains and hinder the sliding of chains, thereby reducing the influence of temperature on the free volume. Therefore, compared with PP, the conductivity of LCBPP is lower at high temperatures, and the breakdown strength increases by 16.2% at 105 °C. This method provides an idea for improving the breakdown strength of PP films at elevated temperatures from the perspective of regulating the microstructure.
Laser-induced THz magnetism of antiferromagnetic CoF2
Authors: Formisano F , Dubrovin R M , Pisarev R V , Kalashnikova A M , Kimel A V
Published: March 2022

Excitation, detection, and control of coherent THz magnetic excitation in antiferromagnets are challenging problems that can be addressed using ever shorter laser pulses. We study experimentally excitation of magnetic dynamics at THz frequencies in an antiferromagnetic insulator CoF2 by sub-10 fs laser pulses. Time-resolved pump-probe polarimetric measurements at different temperatures and probe polarizations reveal laser-induced transient circular birefringence oscillating at the frequency of 7.45 THz and present below the Néel temperature. The THz oscillations of circular birefringence are ascribed to oscillations of the magnetic moments of Co2+ ions induced by the laser-driven coherent E

g
phonon mode via the THz analogue of the transverse piezomagnetic effect. It is also shown that the same pulse launches coherent oscillations of the magnetic linear birefringence at the frequency of 3.4 THz corresponding to the two-magnon mode. Analysis of the probe polarization dependence of the transient magnetic linear birefringence at the frequency of the two-magnon mode enables identifying its symmetry.
Nonequilibrium Green’s function method for phonon heat transport in quantum system
Authors: Zeng Yu-Jia , Ding Zhong-Ke , Pan Hui , Feng Ye-Xin , Chen Ke-Qiu
Published: March 2022

Phonon heat transport property in quantum devices is of great interesting since it presents significant quantum behaviors. In the past few decades, great efforts have been devoted to establish the theoretical method for phonon heat transport simulation in nanostructures. However, modeling phonon heat transport from wavelike coherent regime to particlelike incoherent regime remains a challenging task. The widely adopted theoretical approach, such as molecular dynamics, semiclassical Boltzmann transport equation, captures quantum mechanical effects within different degrees of approximation. Among them, Non-equilibrium Green’s function (NEGF) method has attracted wide attention, as its ability to perform full quantum simulation including many-body interactions. In this review, we summarized recent theoretical advances of phonon NEGF method and the applications on the numerical simulation for phonon heat transport in nanostructures. At last, the challenges of numerical simulation are discussed.
Reciprocal-FDK reconstruction for x-ray diffraction computed tomography
Authors: Liang Kaichao , Zhang Li , Xing Yuxiang
Published: March 2022

Objective. X-ray diffraction (XRD) technology uses x-ray small-angle scattering signal for material analysis, which is highly sensitive to material inter-molecular structure. To meet the high spatial resolution requirement in applications such as medical imaging, XRD computed tomography (XRDCT) has been proposed to provide XRD intensity with improved spatial resolution from point-wise XRD scan. In XRDCT, 2D spatial tomography corresponds to a 3D reconstruction problem with the third dimension being the XRD spectrum dimension, i.e. the momentum transfer dimension. Current works in the field have studied reconstruction methods for either angular-dispersive XRDCT or energy-dispersive XRDCT for small samples. The approximations used are only suitable for regions near the XRDCT iso-center. A new XRDCT reconstruction method is needed for more general imaging applications. Approach. We derive a new FDK-type reconstruction method (Reciprocal-FDK) for XRDCT without limitation on object size. By introducing a set of reciprocal variables, the XRDCT model is transformed into a classical cone-parallel CT model, which is an extension of a circular-trajectory cone-beam CT model, after which the FDK method is applied for XRDCT reconstruction. Main results. Both analytical simulation and Monte Carlo simulation experiments are conducted to validate the XRDCT reconstruction method. The results show that when compared to existing analytical reconstruction methods, there are improvements in the proposed Reciprocal-FDK method with regard to relative structure reconstruction and XRD pattern peak reconstruction. Since cone-parallel CT does not satisfy the data completeness condition, cone-angle effect affects the reconstruction accuracy of XRDCT. The property of cone-angle effect in XRDCT is also analyzed with ablation studies. Significance. We propose a general analytical reconstruction method for XRDCT without constraint on object size. Reciprocal-FDK provides a complete derivation and theoretical support for XRDCT reconstruction by analogy to the well-studied cone-parallel CT model. In addition, the intrinsic problem with the XRDCT data model and the corresponding reconstruction error are discussed for the first time.
Halides formation dynamics in nanosecond and femtosecond laser-induced breakdown spectroscopy
Authors: Bordel N , Fernández-Menéndez L J , Méndez-López C , González-Gago C , Pisonero J
Published: March 2022

Laser-induced breakdown spectroscopy (LIBS) is an analytical technique based on the measurement of the emitted radiation coming from a laser-induced plasma (LIP) created after irradiation of a sample by a short-duration laser pulse. Research on molecular presence in LIPs has increased because the use of molecular emission has proven an encouraging way to improve LIBS abilities. LIPs are dynamic plasmas with fast time and spatial evolutions, in which atoms and molecules can follow different paths in their evolution and distribution. Molecular creation mechanisms within LIPs are still a challenging issue under investigation and the prevalence of some specific mechanisms are dependent on experimental conditions (sample nature, laser parameters, surrounding atmosphere…). In this work, different time and spatially solved experiments were carried out in ns- and fs-LIBS to investigate the dynamics of alkaline-earth (Ca) halide (F) diatomic molecule formation. Experiments were carried out on powdered CaF2 samples for both ns- and fs-LIBS. The effects of a gas flow (air, He, Ar) over the plume are investigated for ns-LIBS. Nebulization-modified ns-LIBS experiments in which the alkaline-earth element is externally added to the plasma plume as an aerosol were carried out on (C2F4)
n
samples. The spatial separation between atomic and molecular emission distribution was found to take place with and without external modifications over the ns-LIP. Behavior in fs-LIPs was determined to differ significantly from analogous experiments with nanosecond lasers, but temporal optimization remains the optimum method for molecular detection as spatial separation was not found to provide any remarkable advantage.
Quantitative analysis of edge breakdown effect of Geiger mode avalanche photo-diodes utilizing optical probe scanning method
Authors: He Tingting , Yang Xiaohong , Tang Yongsheng , Wang Rui , Liu Yijun
Published: March 2022

Planar InGaAs/InP avalanche photo diodes (APDs) are preferred single-photon detectors in the near-infrared region. They are usually fabricated using the double-diffusion method to avoid edge breakdown. However, this effect cannot be avoided completely as the bias voltage increases in the Geiger mode (GM). In this study, the influence of the deep diffusion window diameter on the premature edge breakdown of GM APDs was quantitatively analyzed using optical probe scanning method. Both numerical simulations and experimental measurements were performed. The electric field and dark current distribution, and the photon current under different optical input positions were numerically simulated. APDs with different deep diffusion window diameters were fabricated and tested to measure the photon current response. According to the normalized scanning photo current, we find that premature edge breakdown diminishes as the diffusion diameter of the device decreases. The position of the maximum electric field gradually shifted to the center as the diameter of the device decreased, and this shift gradually increased as the diameter decreased. The influence of edge breakdown was found to be avoided on the APD with a diameter of 10 μm, indicated by the avalanche gain reaching the maximum at the center, and the overlapping of optical and maximum electric gain regions is realized, which is crucial for high detection efficiency and low dark count of single photon detection.
60-GHz third-order on-chip bandpass filter using GaAs pHEMT technology
Authors: Xu Kai-Da , Weng Xiaoyu , Li Jianxing , Guo Ying-Jiang , Wu Rui , Cui Jianlei , Chen Qiang
Published: March 2022

A 60 GHz third-order on-chip bandpass filter (BPF) based on half-mode substrate integrated waveguide (HMSIW) cavity is synthesized using GaAs pHEMT technology. Two coupling slots are etched to divide the HMSIW cavity into three resonators, and then a third-order Chebyshev BPF is designed with predicted transmission zero, return loss and bandwidth through the synthesis method. The theoretical and extracted external quality factor and coupling coefficients are used to determine the dimensions of the BPF. For demonstration, a BPF sample with a bandwidth of 29.2% is fabricated, and its simulations and measurements are in good agreement.
Boron based new high entropy alloy superconductor Mo0.11W0.11V0.11Re0.34B0.33
Authors: Motla Kapil , Soni V , Meena P K , Singh R P
Published: March 2022

Superconducting high entropy alloys (HEAs) are new members of disordered superconductors. We report the synthesis and investigation of a new superconducting high entropy alloy Mo0.11W0.11V0.11Re0.34B0.33 (MWVRB). It crystallized in the tetragonal CuAl2 crystal structure with space group (I4/mcm). Comprehensive transport, magnetization and heat capacity measurements confirmed bulk type-II superconductivity having transition temperature T
C
= 4.0 K. The low temperature electronic specific heat suggests a fully gapped superconducting state in the weak coupling limit.
Synchronization of a genetic oscillator with the cell division cycle
Authors: Knotz Gabriel , Parlitz Ulrich , Klumpp Stefan
Published: March 2022

Genetic circuits that control specific cellular functions are never fully insulated against influences of other parts of the cell. For example, they are subject to periodic modulation by the cell cycle through volume growth and gene doubling. To investigate possible effects of the cell cycle on oscillatory gene circuits dynamics, we modelled a simple synthetic genetic oscillator, the repressilator, and studied hallmarks of the resulting nonlinear dynamics. We found that the repressilator coupled to the cell cycle shows typical quasiperiodic motion with discrete Fourier spectra and windows in parameter space with synchronization of the two oscillators, with a devil’s stair case indicating the Arnold tongues of synchronization. In the case of identical parameters for the three genes of the repressilator and simultaneous gene duplication, we identify two classes of synchronization windows, symmetric and asymmetric, depending on whether the trajectories satisfy a discrete three-fold rotation symmetry, corresponding to cyclic permutation of the three genes. Unexpectedly changing the gene doubling time revealed that the width of the Arnold tongues is connected to that three-fold symmetry of the synchronization trajectories: non-simultaneous gene duplication increases the width of asymmetric synchronization regions, for some of them by an order of magnitude. By contrast, there is only a small or even a negative effect on the window size for symmetric synchronization. This observation points to a control mechanism of synchronization via the location of the genes on the chromosome.
Effect of neuromorphic transcutaneous electrical nerve stimulation (nTENS) of cortical functional networks on tactile perceptions: an event-related electroencephalogram study
Authors: Liu Yafei , Xi Pengcheng , Li Bo , Zhang Minjian , Liu Honghao , Tang Rongyu , Xin Shan , Huang Qiang , He Jiping , Liu Zhiqiang , Yuan Zengqiang , Lang Yiran
Published: March 2022

Abstract

Background. Transcutaneous electrical nerve stimulation (TENS) is generally applied for tactile feedback in the field of prosthetics. The distinct mechanisms of evoked tactile perception between stimulus patterns in conventional TENS (cTENS) and neuromorphic TENS (nTENS) are relatively unknown. This is the first study to investigate the neurobiological effect of nTENS for cortical functional mechanism in evoked tactile perception. Methods. Twenty-one healthy participants were recruited in this study. Electroencephalogram (EEG) was recorded while the participants underwent a tactile discrimination task. One cTENS pattern (square pattern) and two nTENS patterns (electromyography and single motor unit patterns) were applied to evoke tactile perception in four fingers, including the right and left index and little fingers. EEG was preprocessed and somatosensory-evoked potentials (SEPs) were determined. Then, source-level functional networks based on graph theory were evaluated, including clustering coefficient, path length, global efficiency, and local efficiency in six frequency bands. Main results. Behavioral results suggested that the single motor units (SMUs) pattern of nTENS was the most natural tactile perception. SEPs results revealed that SMU pattern exhibited significant shorter latency in P1 and N1 components than the other patterns, while nTENS patterns have significantly longer latency in P3 component than cTENS pattern. Cortical functional networks showed that the SMU pattern had the lowest short path and highest efficiency in beta and gamma bands. Conclusion. This study highlighted that distinct TENS patterns could affect brain activities. The new characteristics in tactile manifestation of nTENS would provide insights for the application of tactile perception restoration.
Multifrequency superscattering driven by symmetry-reduced resonators
Authors: Shamkhi H. K. , Canós Valero A.
Published: March 2022

We unveil novel mechanisms to achieve superscattering by investigating the resonances’ profile of non-Hermitian Hamiltonian structures lacking spherical symmetry. We show that superscattering can be obtained within a single scattering channel due to a contribution of a single strongly-coupled mode. Such phenomenon can’t be observed in Mie-based resonators. We then spatially and spectrally engineer modes of multi-resonators in a cluster to realize broadband superscattering with ultra-strong resonances at several frequency points.
Self-assembling plasmonic film of different-sized gold nanoparticles as a SERS substrate: the optimization study
Authors: Maleeva K. A. , Baranov M. A. , Bogdanov K. V.
Published: March 2022

The features of improving self-assembled films based on different-sized gold particles were investigated in this work. A study of the SERS signal was carried out to compare SPF samples consisting of gold nanoparticles of different sizes. For this purpose, colloids with different particle sizes were synthesized. These are spherical particles 20 nm and 40 nm in diameter and lamellar particles with an approximate size of 60x40x15 nm. Optimization of the concentration of the self-assembly agent of the reaction mixture in the preparation of the self-assembled plasmon film (SPF) has been carried out. The concentration of the self-collecting agent in the organic phase, at which the maximum values of the SERS enhancement of the signal were observed, is 10−5 M. The showing the reproducibility of the SERS signal for samples with the maximum enhancing of the SERS signal value is close for the all the studied particle sizes consisted SPF.
Challenges in the Additive Manufacture of Single and Multi-Core Optical Fibres
Authors: Canning J. , Chu Y. , Luo Y. , Peng G.D. , Zhang J.
Published: March 2022

Single and multi-core preforms doped with Bi and Er are fabricated using additive manufacture and drawing into optical fibre. We observe an increasing trend towards shape distortion with increasing number of cores. This is explained by noting that the composite effective softening point falls as the number of doped cores rises. The use of a silica cladding tube elevates the drawing temperature unnecessarily.
Systematic errors of THz absorption gas spectroscopy due to interference in a multi-pass cell
Authors: Semenova A. V. , Anfertev V. A. , Yablokov A. A. , Knyazeva T. D.
Published: March 2022

Multi-pass spectroscopic absorption cells are commonly used in gas spectroscopy to increase the sensitivity of the measurements. The possibility of systematic errors of such measurements was shown in this paper, even for the case when intrinsic transmittance of the cell alters weakly on the line width. The errors could be manifested both in perturbation of the shape of the absorption line and in the sufficient overestimation or underestimation of the absorption strength.
Towards plasmon mapping of SERS-active Ag dewetted nanostructures using SPELS
Authors: Beshr M , Dexter E , Tierney P E , Meade A D , Murphy S , Amarandei G
Published: March 2022

Thermal dewetting of silver thin flm can lead to SERS-active Ag nanoparticles. Here, we report our progress towards using scanning probe energy loss spectroscopy (SPELS) to map the plasmonic behaviour of SERS-active Ag nanoparticles (NP) by investigating NPs produced through the dewetting study of Ag thin flms on SiO2/Si and Ti/SiO2/Si substrates. The nanoparticles size and spatial distribution were controlled by the deposition and thermal annealing parameters. The results of preliminary SPELS measurements of these structures, alongside SERS data show that there is a correlation between the Raman enhancement and the nanoparticle size and interparticle spacing.
Enhanced Photocatalytic Activity of ZnO Nanorods/(Graphene Oxide, Reduced Graphene Oxide) for Degradation of Methyl Orange Dye
Authors: Sánchez Luis A. , Huayta Brian E. , Ramos Pierre G. , Rodriguez Juan M.
Published: March 2022

ZnO has been well-known as a significant photocatalyst material due to its high surface area, efficient charge transport, and superior photosensitivity. Even though photocatalysis using bare ZnO NRs is useful in pollutant remediation, two main drawbacks scale down their performance as photocatalysts. First, ZnO NRs absorb mainly the UV light, which compromises a small portion of the solar spectrum, and second, the high recombination rate in the ZnO NRs prevents the path of electron-hole outward and then reduces the photocatalysis efficiency. In this work, ZnO-NRs, ZnO-NRs/Graphene Oxide (GO), and ZnO-NRs/Reduced Graphene Oxide (rGO) array composites were vertically grown on conductive glass substrates of SnO2:F (FTO). The films were synthesized by hydrothermal method using ZnO seed layers deposited by spray pyrolysis technique. The nanosheets of GO and rGO were anchored onto the surface of the as-prepared ZnO-NRs by using the spray deposition technique (SDT). The photocatalytic activity of these materials was studied by analyzing the degradation of methylene orange (MO) in an aqueous solution under ultraviolet light, and we found that the decoration of ZnO-NRs with nanosheets of GO and rGO resulted in a significant enhancement of the photocatalytic degradation efficiency, where ZnO-NRs/rGO are more efficient than ZnO-NRs/GO and the latter better than pure ZnO-NRs.
A 20 Gbps PAM4 data transmitter ASIC for particle physics experiments
Authors: Zhang L. , Cruda E.M. , Chao C-P. , Chen S-W. , Deng B. , Francisco R. , Gong D. , Guo D. , Hou S. , Huang G. , Huang X. , Kulis S. , Li C.-Y. , Liu C. , Liu E.R. , Liu T. , Moreira P. , Prinzie J. , Sun H. , Sun Q. , Sun X. , Wong G. , Yang D. , Ye J. , Zhang W.
Published: March 2022

We present the design and test results of a novel data transmitter ASIC operating up to 20.48 Gbps with 4-level Pulse-Amplitude-Modulation (PAM4) for particle physics experiments. This ASIC, named GBS20, is fabricated in a 65 nm CMOS technology. Two serializers share a 5.12 GHz Phase Locked Loop (PLL) clock. The outputs from the serializers are combined into a PAM4 signal that directly drives a Vertical-Cavity-Surface-Emitting-Laser (VCSEL). The input data channels, each at 1.28 Gbps, are scrambled with an internal 27-1 Pseudo-Random Binary Sequence (PRBS), which also serves as a frame aligner. GBS20 is tested to work at 10.24 and 20.48 Gbps with a VCSEL-based Transmitter-Optical-Subassembly (TOSA). The power consumption of GBS20 is below 238 mW and reduced to 164 mW in the low-power mode.
Drivers of historical and projected changes in diverse boreal ecosystems: fires, thermokarst, riverine dynamics, and humans
Authors: Jorgenson M Torre , Brown Dana R N , Hiemstra Chris A , Genet Hélène , Marcot Bruce G , Murphy Richard J , Douglas Thomas A
Published: March 2022

Alaska has diverse boreal ecosystems across heterogeneous landscapes driven by a wide range of biological and geomorphic processes associated with disturbance and successional patterns under a changing climate. To assess historical patterns and rates of change, we quantified the areal extent of ecotypes and the biophysical factors driving change through photo-interpretation of 2200 points on a time-series (∼1949, ∼1978, ∼2007, ∼2017) of geo-rectified imagery for 22 grids across central Alaska. Overall, 68.6% of the area had changes in ecotypes over ∼68 years. Most of the change resulted from increases in upland and lowland forest types, with an accompanying decrease in upland and lowland scrub types, as post-fire succession led to mid- and late-successional stages. Of 17 drivers of landscape change, fire was by far the largest, affecting 46.5% of the region overall from 1949 to 2017. Fire was notably more extensive in the early 1900s. Thermokarst nearly doubled from 3.9% in 1949 to 6.3% in 2017. Riverine ecotypes covered 7.8% area and showed dynamic changes related to channel migration and succession. Using past rates of ecotype transitions, we developed four state-transition models to project future ecotype extent based on historical rates, increasing temperatures, and driver associations. Ecotype changes from 2017 to 2100, nearly tripled for the driver-adjusted RCP6.0 temperature model (30.6%) compared to the historical rate model (11.5%), and the RCP4.5 (12.4%) and RCP8.0 (14.7%) temperature models. The historical-rate model projected 38 ecotypes will gain area and 24 will lose area by 2100. Overall, disturbance and recovery associated with a wide range of drivers across the patchy mosaic of differing aged ecotypes led to a fairly stable overall composition of most ecotypes over long intervals, although fire caused large temporal fluctuations for many ecotypes. Thermokarst, however, is accelerating and projected to have increasingly transformative effects on future ecotype distributions.
Complexified stable and unstable manifolds and chaotic tunneling
Authors: Koda Ryonosuke , Shudo Akira
Published: March 2022

Quantum tunneling in nonintegrable systems is studied based on the complex semiclassical analysis in the time domain. The theory of complex dynamical systems predicts that complexified stable and unstable manifolds form the skeleton of the dynamics in phase space, and mixing and ergodicity hold even for the mixed system. After surveying some rigorous results derived for the Hénon map, we numerically verify that some fundamental properties thus predicted can actually be observed, and then investigate natures of complexified stable and unstable manifolds since they guide the complex orbits controlling the tunneling transition in the mixed phase space. In particular, for a properly designed scattering map, we examine the imaginary action associated with the stable manifolds for the periodic orbits in the real plane and find that the orbits tending to the sticky zone of the KAM region provide the most dominant contribution in the semiclassical sum. It is worth emphasizing that the behavior of such dominant orbits is affected by the presence of chaos in the complex plane, which is an aspect far beyond the scope of the dynamics in the real plane.
Prediction of Compressive Strength of Polyvinyl Alcohol fiber Reinforced Bendable Concrete
Authors: Srinivasa C H , Venkatesh
Published: March 2022

Engineered Cementitious Composite or Bendable concrete is a new generation concrete which possesses higher potency and improved durability characteristics. In addition to the potency, the knowledge about durability is very precious for sustainable development in the field of construction industries. Use of mineral admixture such as fly ash contributes a lot in sustainable development whereas; robustness of concrete can easily be enhanced by use of Polyvinyl Alcohol (PVA) fibers. The elevated potency and improved durability of concrete will be achieved by scientifically tailoring various ingredients of the concrete. The knowledge of potency of all concrete in compression is one of the most essential prerequisite material goodness but it calls for costly and time-consuming experiments. Hence, a mathematical model to predict the compressive potency is presented in this paper. Two constants P and Q have been considered as the essential properties for the concrete blend. The constant, P is established for a “measure of Rate of Gain in Potency and constant, Q is established for a measure of “Grade of Potency.” Once the constants P and Q are defined for the blend, the Potency of concrete at varied ages for varied percentages of PVA fibers will be predicted using this Mathematical Model.
Ferrochrome Slag characterization and its compatibility with Quarry dust in Flexible pavement
Authors: Ajay CH , Durga Rani K
Published: March 2022

Exhaustion of locally available materials and increasing hauling charges gained the potential for the exploration of cost-effective alternative materials in the construction industry. Broad endeavours have been made over numerous years on the utilization of industrial waste, yet scant exploration is being done on ferrochrome slag. Ferrochrome slag is an industrial by-product obtained from stainless steel production. Several highway laboratory tests on the characterization of ferrochrome slag are carried out, and the physical and mechanical properties of ferrochrome slag are observed to fulfil MoRTH specifications. Deficiency of fines is observed in the gradation of ferrochrome slag, so quarry dust is incorporated for mechanical stabilization. Ferrochrome slag and quarry dust are blended in different proportions to check the gradation suitability as sub-base and base courses in flexible pavement. Modified Proctor Method of compaction is performed for the ferrochrome slag and quarry dust combinations to carry out the California Bearing Ratio (CBR) test at Maximum Dry Density (MDD) and Optimum Moisture Content (OMC). Studies have shown that the combinations of ferrochrome slag and quarry dust in 70/30 and 60/40 proportions are well graded and have reached the required gradation for use as cement-treated sub-base and base layers in flexible pavement.
Comparative study on strength and durability of concrete upon partial substitution of fly ash and bagasse ash in conventional concrete
Authors: Susmitha P. J. R. L. P. , Kanta Rao M.
Published: March 2022

The need for concrete is continuously increasing which also leads to a proportional increase in cement demand. The percentage increase of cement manufacturing is 3% per annum. Due to the augmented consumption of cement, the emission of carbon-di-oxide is increasing day by day. CO2 accounts for approximately 65% of global warming among greenhouse effect. The notorious impacts caused due to the cement utilization gave direction to this research for the partial replacement of class F fly ash and bagasse ash burnt at 1000°C in the conventional concrete. Comparative study is performed by casting mix with fly ash replaced at 0% to 40% at 5% interval and accordingly other mixes with bagasse ash replaced with 0% to 40% at 5% interval by weight of cement in the concrete and cured for 28, 56, and 90 days. Experimental investigations were carried out to determine mechanical parameters like compressive strength, split tensile strength, flexural strength, and durability aspects like resistance to chloride ion permeability, acid attack. Micro-structural investigations were carried out to determine the presence of peak, the composition of elements through X-ray Diffraction (XRD). Based on the research, it was concluded that fly ash can be replaced up to 40% and bagasse ash up to 15% in the concrete in terms of both strength and durability aspects. Fly ash replacement resulted in the maximum later strength achievement of 74 MPa at 30% replacement while the bagasse ash incorporation resulted in maximum early strength attainment of 61.9 MPa at 15% replacement.
An Innovative Approach on Pet Bottles Compiled with Waste Materials to Produce Eco-friendly Concrete
Authors: Gunasekar S , Ramesh N. , Parthiban P , Ramesh S.
Published: March 2022

PET bottles, such as water bottles, cool drink bottles, and oil storage bottles, are becoming increasingly popular in India. Bottles used to package water take over 1,000 years to biodegrade and, if incinerated, contain poisonous gases. Recycling these PET bottles requires more attention however, this was also among the most famous effective ways to minimize waste. Only PET bottles, however, it’s recyclable; all other bottles must be discarded. In fact, only 1 out of 5 containers are able to be sent to the recycle bin. The strength criteria was studied in PET bottles by filled up with different waste materials such as M-sand, Quarry dust, Fly ash, River sand and Construction debris. These filled bottles are inserted in concrete cube mould for minimising the concrete quantity and strength parameters were studied. Based on the experimental work, it was identified that, PET bottles having good compression resistance and also act as a filler material in concrete.
Performance evaluation of glass fiber reinforced high-performance concrete with silica fume and nano-silica
Authors: kumar Pidugu Prasanna , Chaitanya Bypaneni Krishna
Published: March 2022

Investigators all around the globe are making unrivaled concrete by varying the proportions and admixtures. Fiber-reinforced concrete has various applications in structural components. Some of the fibers like glass, carbon, polypropylene, and aramid fibers give an improvement in generous properties like hardened, durability, stiffness, toughness, shrinkage. The purpose of this research is to investigate the properties of glass fiber reinforced high-performance concrete (GFRHC) for arriving high-performance trail mixes are prepared with cement replacement with silica fume (SF) ranging from 0% to 25%. An optimum mix is chosen in that constant 1.15 % cement is replicate with nano-silica. For that optimized mix along with nano-silica, glass fibers are induced at 1%, 2%, 3%, and 4% by weight of cement. 100×100×100mm cube moulds, cylinder moulds of 100×200mm, and beam moulds of 100×100×500 mm are prepared and cured for 7, 28 days then hardened strength are evaluated. The result shows that at 10% replacement of cement with silica fume at constant w/b ratio 0.31 shown 59.06 Mpa for Mix-3 and at 2% addition of glass fibers shows the 69.4Mpa, 9.57 Mpa, and 7.91 Mpa of compressive strength, split tensile strength, and modulus of rupture for Mix-8. The quality of concrete of all the mixes are is excellent at 2% addition of glass fiber UPV value is 5281m/s.
Pervious Concrete: An Overview and Experimental Study
Authors: Hoshitha T S S , Mallinadh Kashyap A , Chandrasekhar Rao T
Published: March 2022

The present climatic changes are occurring because of the various activities of the humans such as urbanization and increasing threat of green-house gas (GHG) emissions resulted in precipitation increase in many geographical areas. In view of this, OPC based pervious concrete (PC) was developed in order to enhance the sustainability of the urban drainage systems (UDS). No fines concrete also coined as OPC based pervious concrete (PC) which is a versatile material with high porosity content applicable in flat work applications which allows the water from various sources such as precipitation and other sources to flow through and in turn recharges the ground water levels. Apart from these aspects, PC can significantly decrease the solar radiation absorption and urban heat storing potential which leads to the protection of the environment as well as the health and safety of the human beings. Generally, no fines concrete generally consists of cementitious paste to overlay the coarse aggregate which relates the vanderwall bond between the coarse aggregate and the cement. However, PC requires periodical maintenance in order to prevent any sort of clogging within the voids by the vegetation and sediments. In the present investigation, the overview of PC as well as the experimentation to study the mechanical strength characteristics by the utilization of industrial waste exhausts materials like fly ash. The study conferred that addition of fly ash to pervious concrete significantly enhances the mechanical strength characteristics of PC. An equation is proposed to establish a correlation between split-tensile strength and flexural strength of PC and it is in good agreement with the previous studies.
Study on strength characteristics of concrete by replacement of fine aggregates and fibre addition to cement using SCC
Authors: Ramya AVSL , Satyaveni A , Sudheer kumar G , Nitish S SS
Published: March 2022

The present investigation is on strength characteristic of hardened concrete with materials re-placement of fine aggregates and addition of fibre by using self-compacting concrete method which is an advanced technology used in improving the construction methodology. The SCC requires an admixture like Poly Carboxylate Ether (PCE) based super – plasticizer (Master Glenium SKY 8630) used as curing compound to improve the efficiency of self-compacting concrete SCC in terms of its performance. As the nominal fine aggregate cost is increasing the re-placement of fine aggregates is done by by-products of steel industry and query dust. Grade of concrete, dosage of admixtures, self-curing compounds, and time of curing are parameters to be considered for investigation. The performance studies include water retention, compressive test and split tensile test. The result analysis shows that crusher dust and foundry sand show increase in tensile and flexural strength at 0.2% of fibre addition. The grade of concrete is M30 is taken for investigation.
Strength Enhancement of Mortar using Biocementation Technique
Authors: Jaya Sri V , Charpe Anuja
Published: March 2022

Biocementation is a technique in which calcium carbonate (CaCO3) gets deposited with the help of ureolytic bacteria. In this study, an attempt has been made to augment the properties of mortar utilizing bacterial solution made with soil bacteria and other nutrients. The consequence of bacterial solution was noticed in two methods. In the first method the bacterial solution is used in preparing the bacterial mortar specimens and in the second method the bacterial solution is used in surface treatment of mortar. Considerable enhancement of 20.08% in compressive strength and 10.52% decrement in water absorption of bacterial mortar over conventional mortar was observed at the end of 56 days of curing period.
Analysis of Various Drought Indices over Mathura Region Using Geo-Spatial Technologies
Authors: Aggile Lakshmi Prasanna , Gautam Shweta , Reddy B.Sudheer Kumar
Published: March 2022

The scarcity of water in any geophysical conditions leads to drought. The vegetation conditions and rainfall need to be assessed efficiently to develop counter measures to tackle the drought. Hence various drought indices such as Vegetation Condition Index (VCI) Standardized Precipitation Index (SPI) and Rainfall Anomaly Index (RAI) were carefully analyzed. Results of VCI showed moderate to severe droughts occurred at study region for the year 2015 in the month of September. SPI and RAI results showed that monsoon months had negative values for all the places in drought year 2015. The eastern part of the research area is found to be prone to dry condition as per the results obtained. The risk of future drought conditions can be minimized with the help of this research.