bluuebunny/crossref_metadata_2025 huggingface dataset:
Anisotropic deformation of 4H-SiC wafers: insights from nanoindentation tests
Authors: Liu Xiaoshuang , Wang Rong , Zhang Junran , Lu Yunhao , Zhang Yiqiang , Yang Deren , Pi Xiaodong
Published: September 2022

In this work, the anisotropic deformation and anisotropic mechanical properties of 4H silicon carbide (4H-SiC) single crystal wafers are proposed by using nanoindentation. The C face of a 4H-SiC wafer has higher hardness and lower fracture toughness than those of the Si face. Because the deformation of 4H-SiC is assisted by the nucleation and slip of basal plane dislocations (BPDs), especially the slip of Si-core partial dislocations (PDs) of the BPDs, the nucleation and slip of the Si-core PDs in the Si face of 4H-SiC is easier than those in the C face, which releases the nanoindentation-induced stress and results in the decrease of the hardness and increase of the fracture toughness of the Si face of 4H-SiC wafers. Due to the hexagonal lattice of 4H-SiC, the hardness along

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of 4H-SiC is higher than that along

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, but the fracture toughness along the

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is lower than that along the

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, as a result of the enhanced glide of dislocations along the most closely-packed direction. The insights gained in this work are expected to shed light on the optimization of the mechanical processing of 4H-SiC wafers.
Three-dimensional modelling of a self-sustained atmospheric pressure glow discharge
Authors: Boutrouche Valentin , Trelles Juan Pablo
Published: September 2022

The atmospheric pressure glow discharge (APGD) is a relatively simple and versatile plasma source used in diverse applications. Stable APGD operation at high currents, generally a challenge due to instabilities leading to glow-to-arc transition, has been demonstrated using actively-controlled cathodic cooling. This article presents the computational modelling and simulation of a self-sustained direct-current APGD in helium within a 10 mm pin-to-plate inter-electrode gap for currents ranging from 4 to 40 mA. The APGD model is comprised of the conservation equations for total mass, chemical species, momentum, thermal energy of heavy-species and of free electrons, and electric charge. The model equations are discretized using a nonlinear variational multi-scale finite element method that has demonstrated superior accuracy in other plasma flow problems, on a temporal and three-dimensional computational domain suitable to unveil the potential occurrence of instabilities. Modelling results show good agreement with experimental measurements of voltage drop and the same trend but higher values of temperature. The higher temperatures obtained by the simulations appear to be due to the absence of a near-cathode heat dissipation model. The results also reveal that the distribution of electron density and of the ratio of atomic helium ions to total ions transitions from monotonically increasing away from the cathode to presenting a minimum near the centre of the gap with increasing current.
Theoretical investigation of lattice-matched III-N-V/Si double-junction solar cells
Authors: Zhang Xiaobin , Liu Liming , Chi Feng , Wang Ke , Lin Kaiwen , Wang Yuehui
Published: September 2022

The lattice-matched III-N-V/Si double-junction (DJ) solar cells are designed with GaNAsP and GaInNP top cells, respectively. Under AM1.5G condition, the efficiencies of III-N-V/Si DJ cells are calculated with variable electron lifetime (τe
) and electron surface recombination velocity (Se
) in top cell. When Se
is 100 cm s−1 and τe
rises from 1 to 1000 ns, the optimal efficiency of GaNAsP/Si cell increases from 31.12% to 36.13% due to the increasing short-circuit current and open-circuit voltage. With τe
of 100 ns, the optimal efficiency keeps at a high value of ∼35% when Se
changes from 10 to 1000 cm s−1, but drops obviously with Se
of 10 000 cm s−1. In comparison, the optimal efficiency of GaNAsP/Si cell is less sensitive to Se
than to τe
. With fixed Se
of 100 cm s−1, GaNAsP/Si cell shifts the optimal top-cell bandgap from 1.716 to 1.787 eV when raising τe
from 1 to 1000 ns. However, the effect of Se
on optimal top-cell bandgap is negligible. For III-N-V/Si cell with 100 ns τe
and 100 cm s−1
Se
, an optimal efficiency is obtained as ∼35.1%, which would be closer to the experimental limit owing to the expectable values of τe
and Se
. Furthermore, the optimal efficiency of GaNAsP/Si cell drops slightly when thinning Si substrate from 300 to 150 μm, but has a maximum of 35.95% with substrate doping of 1 × 1016 cm−3 when the doping concentration varies from 1 × 1015 to 1 × 1018 cm−3. The results and discussion in this work may act as a guidance for studying III-N-V/Si DJ cell.
A low-cost digital coding metasurface applying modified ‘crusades-like’ cell topologies for broadband RCS reduction
Authors: Wang Chao , Wang Ru-Zhi , An Ze-Lin , Liu Li-Ying , Zhou Yun-Sheng , Tang Zhi-Xiang , Wang Wei-Dong , Zhang Sheng-Jun
Published: September 2022

The popularity of metasurfaces (MSs) has been continuously grown due to their powerful ability to manipulate electromagnetic waves. One of their important application areas is radar stealth technology, in particular, the realization of radar cross section (RCS) reduction. However, the high costs of substrate material limit its large-scale applications. In this paper, a binary digital coding metasurface (DCM) with novel modified ‘crusades-like’ cell topologies is proposed and implemented using a low-cost FR4 substrate to achieve broadband RCS reduction (RCSR). To realize the 1-bit DCM, initially, two elements with rotational symmetry are chosen for polarization insensitive properties while considering an unconventional phase deviation criteria. Next, the optimal hybrid coding layout is given out by using a genetic algorithm and antenna array theory. Last, the proposed novel MS prototype composed of 40 × 40 unit cells is fabricated and measured to validate the RCSR behaviour predicted by full-wave simulation. The results show a good consistency between the theoretical simulation and experimental measurement from 7.9 to 15.8 GHz. In addition, the simulation results indicate that the designed MS features high angular stability. Our work may provide a promising approach and good reference for the low-cost MS design in radar stealth applications.
Design of experiments: a statistical tool for PIV uncertainty quantification
Authors: Adatrao Sagar , van der Velden Simone , van der Meulen Mark-Jan , Bordes Marc Cruellas , Sciacchitano Andrea
Published: September 2022

A statistical tool called design of experiments (DOEs) is introduced for uncertainty quantification in particle image velocimetry (PIV). DOE allows to quantify the total uncertainty as well as the systematic uncertainties arising from various experimental factors. The approach is based on measuring a quantity (e.g. time-averaged velocity or Reynolds stresses) several times by varying the levels of the experimental factors which are known to affect the value of the measured quantity. Then, using Analysis of Variances, the total variance in the measured quantity is computed and hence the total uncertainty. Moreover, the analysis provides the individual variances for each of the experimental factors, leading to the estimation of the systematic uncertainties from each factor and their contributions to the total uncertainty. The methodology is assessed for planar PIV measurements of the flow over a NACA0012 airfoil at 15 degrees angle of attack considering five experimental factors, namely camera aperture, inter-frame time separation, interrogation window size, laser sheet thickness and seeding density. Additionally, the methodology is applied to the investigation by stereoscopic PIV of the flow at the outlet of a ducted Boundary Layer Ingesting propulsor. The total uncertainty in the time-averaged velocity as well as the constituent systematic uncertainties due to the experimental factors, namely camera aperture, inter-frame time separation, interrogation window size and stereoscopic camera angle, are quantified.
A novel unbalanced weighted KNN based on SVM method for pipeline defect detection using eddy current measurements
Authors: Lu Senxiang , Yue Yiqiao , Liu Xiaoyuan , Wu Jing , Wang Yongqiang
Published: September 2022

Pipeline safety inspections are particularly important because they are the most common means of energy transportation. In order to avoid pipe leakage, eddy current inspection is often used in metal pipe defect detection. However, in practice, due to problems such as noise and interference, a small number of labeled pipeline defect samples, and unbalanced sample distribution, the detection task cannot be completed. To address the above problems, this study proposes an unbalanced weighted k-nearest neighbor (KNN) based on support vector machine (SVM) defect detection algorithm. The multi-segment hybrid adaptive filtering algorithm is adopted to improve the identification of strong interference and large noise eddy current signals in this paper while retaining useful information such as defects. At the same time, the unbalanced weighted KNN based on the SVM defect detection algorithm is used to solve the problems of low accuracy and large limitations of the algorithm. The experimental results show that, compared with the KNN and SVM algorithms, the detection rate, false detection rate, and missed detection rate of defects are significantly improved.
Optical properties of black silicon structures ALD-coated with Al2O3
Authors: Schmelz David , Gerold Kristin , Käsebier Thomas , Sergeev Natali , Szeghalmi Adriana , Zeitner Uwe D
Published: September 2022

Atomic layer deposited (ALD) Al2O3 coatings were applied on black silicon (b-Si) structures. The coated nanostructures were investigated regarding their reflective and transmissive behaviour. For a systematic study of the influence of the Al2O3 coating, ALD coatings with a varying layer thickness were deposited on three b-Si structures with different morphologies. With a scanning electron microscope the morphological evolution of the coating process on the structures was examined. The optical characteristics of the different structures were investigated by spectral transmission and reflection measurements. The usability of the structures for highly efficient absorbers and antireflection (AR) functionalities in the different spectral regions is discussed.
Micro-mechanisms of failure in nano-structured maraging steels characterised through in situ mechanical tests
Authors: Jacob Kevin , Sahasrabuddhe Hrushikesh , Hohenwarter Anton , Dixit Saurabh , Jaya Balila Nagamani
Published: September 2022

High-pressure-torsion (HPT) processing introduces a large density of dislocations that form sub-grain boundaries within the refined nano-scale structure, leading to changes in precipitate morphology compared to hot-rolled maraging steels. The impact of such nanostructuring on the deformation and fracture micro-mechanisms is being reported for the first time using in situ characterization techniques along with transmission electron microscopy and atom probe tomography analysis, in this study. Digital image correlation has been used to quantify the full field strain maps in regions of severe strain localization as well as to determine the fracture toughness through critical crack tip opening displacements. It is seen that the phenomenon of planar slip leads to strain softening under uniaxial deformation and to crack branching under a triaxial stress state in hot rolled maraging steels. On the other hand, nano-structuring after HPT processing creates a large number of high angle grain boundaries as dislocation barriers, leading to strain hardening under uniaxial tension and nearly straight crack path with catastrophic fracture under triaxial stress state. Upon overaging, the hot-rolled sample shows signature of transformation induced plasticity under uniaxial tension, which is absent in the HPT processed overaged samples, owing to the finer reverted austenite grains containing higher Ni concentration in the latter. In the overaged fracture test samples of both the hot-rolled and HPT conditions, crack tips show a signature of strain induced transformation of the reverted austenite to martensite, due to the accompanying severe strain gradients. This leads to a higher fracture toughness even while achieving high strengths in the overaged conditions of the nanocrystalline HPT overaged samples. The results presented here will aid in design of suitable heat treatment or microstructure engineering of interface dominated nano-scale maraging steels with improved damage tolerance.
Buckling behavior of ternary one-dimensional van der Waals heterostructures
Authors: Gao Bingjie , Lin Shu , Wan Jing , Cai Haifang , Zhu Zuoquan
Published: September 2022

One-dimensional van der Waals heterostructures (1D vdWHs) may suffer from external compression when applied in field-effect, light-emitting and photovoltaic devices. Ternary 1D vdWHs were recently reported to be successfully synthesized (Xiang et al 2020 Science
367, 537). In present work, the buckling behavior of ternary 1D vdWH consisting of an inner carbon nanotube, a middle boron nitride nanotube and an outer molybdenum disulfide nanotube is extensively investigated by using molecular dynamics simulations. We find that the composite can effectively enhance the capability of axial compression of the inner nanotubes. The 1D vdWH gradually loses its stability under uniaxial compression and the critical stress of buckling decreases as the temperature increases. Slenderness ratio α of 4.8 ≤ α ≤ 7.2 has a slight influence on the strength and stability of ternary 1D vdWH under axial compression. To obtain a 1D vdWH with best compressive stability and strength, there is an optimal diameter existing for any specific length. Our work provides guidance for the design of 1D vdWH with desired compressive stability.
Dynamically defined subsets of generic self-affine sets*
Authors: Bárány Balázs , Troscheit Sascha
Published: September 2022

In dynamical systems, shrinking target sets and pointwise recurrent sets are two important classes of dynamically defined subsets. In this article we introduce a mild condition on the linear parts of the affine mappings that allow us to bound the Hausdorff dimension of cylindrical shrinking target and recurrence sets. For generic self-affine sets in the sense of Falconer, that is by randomising the translation part of the affine maps, we prove that these bounds are sharp. These mild assumptions mean that our results significantly extend and complement the existing literature for recurrence on self-affine sets.
Unique data sets aid in detecting and proving contract cheating in numerical examination questions
Authors: Lim (林百君) Kieran Fergus
Published: September 2022

Undergraduate first-year courses are often mandatory for students in a variety of majors and degrees. Many students view these core courses as of little interest and relevance, which is associated with lack of motivation for study and can lead to cheating. Contract cheating in text-based is difficult to detect and prove. Contract cheating in numerical-calculation-based assessments is even harder to detect and prove. This paper discusses how unique identifying information can be incorporated into numerical assessments and how unique data sets can be used to both detect and prove contract cheating. Finally, some measures to discourage contract cheating are discussed.
Suggestions on the teaching of atmospheric pressure at university and secondary school levels
Authors: Giulotto Enrico , Malgieri Massimiliano
Published: September 2022

The distinction between pressure in a liquid and in a gas is often treated in a cursory way, or not treated at all, even in university level textbooks. Most texts fail to point out the relation between pressure and density in a gas as compared to pressure in a—virtually incompressible—liquid. In many instances this also results in a dismissive treatment of atmospheric pressure. In this paper we suggest that in the physics curriculum of university and secondary school students, kinetic theory of gases be treated before fluid mechanics and thermodynamics. In this way, the definitions of pressure P and absolute temperature T in a gas can be derived consistently, with the remarkable advantage that the links between the macroscopic parameters P and T and the velocity of molecules—a microscopic parameter—are made clear at an early stage, as well as the relation between P and density ρ.
2D-materials-integrated optoelectromechanics: recent progress and future perspectives
Authors: Peng Mingzeng , Cheng Jiadong , Zheng Xinhe , Ma Jingwen , Feng Ziyao , Sun Xiankai
Published: September 2022

The discovery of two-dimensional (2D) materials has gained worldwide attention owing to their extraordinary optical, electrical, and mechanical properties. Due to their atomic layer thicknesses, the emerging 2D materials have great advantages of enhanced interaction strength, broad operating bandwidth, and ultralow power consumption for optoelectromechanical coupling. The van der Waals (vdW) epitaxy or multidimensional integration of 2D material family provides a promising platform for on-chip advanced nano-optoelectromechanical systems (NOEMS). Here, we provide a comprehensive review on the nanomechanical properties of 2D materials and the recent advances of 2D-materials-integrated nano-electromechanical systems and nano-optomechanical systems. By utilizing active nanophotonics and optoelectronics as the interface, 2D active NOEMS and their coupling effects are particularly highlighted at the 2D atomic scale. Finally, we share our viewpoints on the future perspectives and key challenges of scalable 2D-materials-integrated active NOEMS for on-chip miniaturized, lightweight, and multifunctional integration applications.
Proof-of-concept study of bolt connection status monitoring using fiber Bragg grating curvature sensor
Authors: Deng Shaohua , Wang Tao , Tan Bohai , Yu Wei , Lu Guangtao
Published: September 2022

For connection status monitoring of bolted joint groups, a novel method with fiber Bragg grating (FBG)-based curvature sensor is proposed. An FBG curvature sensor with an inextensible elastic matrix and an offset grating is adopted and clamped between a fixed support and the monitored bolt in a plane bending status. Based on the shape deformation of the FBG curvature sensor induced by the bolt loosening, the bending curvature change of the elastic matrix is measured by the FBG. By detecting the wavelength shift of the FBG induced by the matrix curvature variation, the relationship between the bolt loosening angle and the wavelength shift of FBG can be obtained, and hence the bolt connection status can be determined by the wavelength shift of FBG. Details of the proposed method are presented, and a surface-bonded FBG curvature sensor is designed, fabricated, and experimentally studied to verify the proposed method, and the parameters on sensing performance are also investigated. Experimental results show that the proposed method can monitor bolt loosening angle with high sensitivity and linear output by adjusting the parameters of the FBG curvature sensor. The looseness angle resolution of the proposed sensor can reach 0.0767°. This paper presents the first attempt to monitor bolt loosening angle using an FBG curvature sensor. With the advantages of high sensitivity and resolution, strong applicability, convenience and reusability for the maintenance of bolts, and ease of forming quasi-distributed sensor networks, the proposed method is able to provide a general solution for the on-line monitoring of bolt connection status for large-span distributed bolted-joint groups.
Investigating the effect of transverse compressive loads on the electromagnetic performance of superconducting CORC® cables
Authors: Yan Jiangtao , Wang Keyang , Gao Yuanwen , Zhou Youhe , Nijhuis Arend
Published: September 2022

High-temperature superconductor (Re)Ba2Cu3O
x
(ReBCO) conductor on round core cable (CORC®) has a large current carrying capacity for high field magnets. Lorentz forces acting on CORC conductors, cause a reduction of the critical current, or even permanent degradation of their performance when exceeding critical values. Transverse compressive stress is one of the principal mechanical stresses when CORC cables are bundled to cable-in-conduit conductors (CICC) conductors capable of operating at currents up to 100 kA in magnetic fields of up to 20 T. In this research, a mechanical-electromagnetic model is developed to study the effect of transverse compressive loads on the electromagnetic performance of CORC cables. A mechanical transverse load on the cable is implemented to simulate the electromagnetic force. A comparison of numerical simulations with experiments for a three-layer CORC cable is first performed to validate the model’s reliability, with particular attention to critical current reduction during the transverse compression process. A novel feature of this paper is that the model developed can analyze both mechanical response under transverse compressive loads and electromagnetic performance under applied AC magnetic fields with low amplitudes. On this basis, the model investigates the effects of winding parameters on the axial strain and critical current reduction of the ReBCO layer in a single-layer CORC cable. The numerical analysis shows that increasing the winding angle can reduce the axial strain and critical current reduction of the ReBCO layer in the contact area. Subsequently, a detailed comparative study is carried out studying the axial strain of the ReBCO layer in the non-contact area with and without taking the winding core into account. In addition, a sudden increase in the magnetization loss is explained when the transverse compressive load reaches a certain level. Finally, a six-layer CORC cable’s electromagnetic analysis is performed, and each tape layer’s critical current reduction is investigated and discussed. The comparison of magnetization loss and current density between six- and single-layer CORC cables in the no-strain case is also given. This finite element model can guide optimizing a cable design for specific application conditions.
The correlation between structure and magneto optical properties of nanostructured Magnesium ferrites upon Molybdenum doping for magnetic and optoelectronic applicability
Authors: Desoky W M , Abd Allah T M
Published: September 2022

Nano-ferrite MgMoxFe2-xO4 (X = 0.0, 0.05, 0.1, 0.15, and 0.3) were synthesized employing citrate sol-gel auto combustion methodology. X-ray diffraction (XRD) reveals the crystal structure of the prepared samples. XRD scrutiny disclosed a single cubic spinel phase for all specimens. Furthermore, the Rietveld analysis based on structure refinement used to determine the microstructural parameters and evaluate the cation distribution. The findings showed that the average crystallite size was ∼39 nm, while the lattice constant ‘a’ increases with increasing Mo concentrations attributable to introducing Mo+6 to supplant Fe+3. The magnetic properties were investigated utilizing VSM magnetometer. The saturation magnetization (Ms) descends with escalating Mo+6 replacement. Consequently, both Rietveld scrutiny and saturation magnetization (Ms) results suggest that the Mo+6 supplanted Fe+3 in octahedral B-locations. On the other hand, reflectance and transmittance were used in optical properties to calculate the refractive index, n, and the extinction coefficient, k. The parameters of optical properties such as infinity, lattice and relaxation time of dielectric constant were estimated. In addition, complex optical conductivity, optical electronegativity and optical transitions of all studied samples were assessed. Finally, the parameters of opto-electrical application, such as the concentration, mobility and resistivity of optical carrier were appraised.
Boosting the solar conversion efficiency of MoSe2/PtX2 (X = O, S) vdW heterostructure by strain and electric field engineering
Authors: Chang Yee Hui Robin , Yeoh Keat Hoe , Jiang Junke , Khong Heng Yen , Mahat Mohd Muzamir , Chai Soo See , Liew Fui Kiew , Tuh Moi Hua
Published: September 2022

Vertically stacking two-dimensional materials via weak van der Waals (vdW) forces is an effective strategy for modulating optoelectronic performance of materials. To accelerate more novel MoSe2-based heterostructure design, the interlayer coupling effect in MoSe2/PtX2 (X = O, S) heterostructure has been systematically studied, from the atomic structure to the electronic and optical properties, on the basis of first-principles calculations and BSE model with scissor inclusion. Density functional theory (DFT) calculations unveil a type-II indirect bandgap measuring between 0.85 and 0.91 eV at HSE06 level, with Bader and charge density difference analyses suggesting occurrence of charge redistributions at the interface and electrons diffusion from MoSe2 to PtX2 layers, driven by large band offsets. The thermodynamic and thermal stabilities of the heterostructures are demonstrated by the negative binding energy and AIMD simulation. The heterostructure interface is influenced by the weak vdW coupling with an equilibrium interlayer distance of 3.01 to 3.08 Å and binding energy of −5.5 to −11.2 meV Å−2, indicating an exothermic process and steady adhesion at the interface. Reasonable lattice mismatch that ranges from 1.5 to 4.7% between the vdW heterostructure and separate monolayers suggests good structure compatibility. The optical performance of the heterostructure was examined using the real and imaginary components of dielectric function, where enhanced light absorption of 104–105 cm−1 and prominent peaks are observed encompassing the infrared to ultraviolet domains. Record high spectroscopic limited maximum efficiency (SLME) of ∼33% was also predicted. The absorption strength of MoSe2/PtO2 and MoSe2/PtS2 enhances with increasing negative external electric field (Eext) and compressive strain, individually, inferring their optical properties modulation by Eext and biaxial strain. Both heterostructures present high carrier mobility up to 1322.98 cm2 V−1 s−1 in zigzag direction.
Scrutinization of coating thickness of Sutterby fluid during isothermal blade coating using lubrication theory: the case of plane coater and exponential coater
Authors: Abbas Z , Hanif A , Khaliq S
Published: September 2022

In the literature, there is a gap regarding the analysis of coating thickness of Sutterby fluid during isothermal blade coating using lubrication theory, focusing on the case of plane coater and exponential coater. During the blade coating processes, this report presents the outcome of a study on an isothermal and incompressible flow of a Sutterby fluid. Both the planar and exponential coaters were considered in the analysis. Lubrication theory was used to simplify the non-dimensional governing equations, which were then solved using the numerical shooting approach and perturbation technique for small values of the fluid parameter. Furthermore, the perturbation results are compared to the numerical results and are in good agreement. As the fluid parameter increases, the shear-thinning effect is noted, leading to an increased velocity profile and coating thickness while reducing blade load. Sutterby fluid parameter develops to be the controlling parameter for Pressure profile and blade load compared to the Newtonian case, which leads to an effective coating process and improves the substrate life.
Optical properties of graphane in infrared range
Authors: Preobrazhensky E I , Oladyshkin I V , Tokman M D
Published: September 2022

The theory of optical effects in hydrogenated graphene (graphane) in the terahertz and infrared range is developed, including the analysis of complex conductivity, reflection coefficient for graphane on a substrate and dispersion of surface plasmon-polaritons. The calculations are based on quite simple analytical approximation of graphane band structure in the vicinity of Γ-point and on the modified model of quantum coherence relaxation. Comparison of the obtained theoretical results with corresponding experimental data can be used both for the determination of graphane characteristics (Fermi level, relaxation rate etc) and for the investigation of potential applications of this material in the design of new optical elements.
Photometric Redshift Estimates using Bayesian Neural Networks in the CSST Survey
Authors: Zhou Xingchen , Gong Yan , Meng Xian-Min , Chen Xuelei , Chen Zhu , Du Wei , Fu Liping , Luo Zhijian
Published: September 2022

Galaxy photometric redshift (photoz) is crucial in cosmological studies, such as weak gravitational lensing and galaxy angular clustering measurements. In this work, we try to extract photoz information and construct its probability distribution function (PDF) using the Bayesian neural networks from both galaxy flux and image data expected to be obtained by the China Space Station Telescope (CSST). The mock galaxy images are generated from the Hubble Space Telescope - Advanced Camera for Surveys (HST-ACS) and COSMOS catalogs, in which the CSST instrumental effects are carefully considered. In addition, the galaxy flux data are measured from galaxy images using aperture photometry. We construct a Bayesian multilayer perceptron (B-MLP) and Bayesian convolutional neural network (B-CNN) to predict photoz along with the PDFs from fluxes and images, respectively. We combine the B-MLP and B-CNN together, and construct a hybrid network and employ the transfer learning techniques to investigate the improvement of including both flux and image data. For galaxy samples with signal-to-noise ratio (SNR) > 10 in g or i band, we find the accuracy and outlier fraction of photoz can achieve σ
NMAD = 0.022 and η = 2.35% for the B-MLP using flux data only, and σ
NMAD = 0.022 and η = 1.32% for the B-CNN using image data only. The Bayesian hybrid network can achieve σ
NMAD = 0.021 and η = 1.23%, and utilizing transfer learning technique can improve results to σ
NMAD = 0.019 and η = 1.17%, which can provide the most confident predictions with the lowest average uncertainty.
CMS improved resistive plate chamber studies in preparation for the high luminosity phase of the LHC
Authors: Uribe Estrada C.
Published: September 2022

The high luminosity expected from the HL-LHC will provide a great opportunity for precise physics measurements and searches for new physics. Nevertheless, the increased rate of particles coming from the collisions will pose a challenge for the CMS detectors. To prepare the muon system for the challenging conditions during the high luminosity phase, several upgrades have been planned and are being developed. Thanks to their fast time and space resolution, resistive plate chambers form part of the trigger system and are installed both in the barrel and endcap regions as a subsystem of the muon detector. As part of the upgrades, the muon forward region will be enhanced with two stations, called RE3/1 and RE4/1, equipped with improved Resistive Plate Chambers (iRPCs). These detectors use thinner electrodes, a narrower gas gap (1.4 mm compared to 2 mm in the current design) and improved front-end electronics. These features allow them to withstand particle rates up to a few kHz/cm2. Furthermore, they will extend the geometrical acceptance of the RPCs from a pseudorapidity of 1.9 to 2.4. In this work we present different studies related to the iRPC prototypes in preparation for the high luminosity phase of the LHC.
The Topmetal-CEE prototype, a direct charge sensor for the beam monitor of the CSR external-target experiment
Authors: You B. , Gao C. , Yang P. , Guo D. , Tian X. , Huang G. , Liu J. , Sun X. , Wang H. , Xiao L. , Huang F. , Feng W. , Ye Q. , Guo Z. , Qiao Y. , Hu Z. , Yang Y. , Zhao C. , Yang H. , Wang Z. , Liu F.
Published: September 2022

The Cooler-Storage-Ring External-target Experiment (CEE) which is being constructed since 2020 is a spectrometer to study the properties of nuclear matter at high baryon density region. We present the design and simulation results of a sensor named Topmetal-CEE which is being developed for an online beam monitor of the CEE. A prototype of the Topmetal-CEE has been designed in a standard CMOS 130 nm process and is being fabricated. The Topmetal-CEE prototype has 180 channels with a pitch of 100 μm. In each channel, electrons are collected by a charge collection electrode which is a top-most metal exposed to the surrounding media, amplified by a charge sensitive amplifier, and then fed into a discriminator. The output of the discriminator is split into two paths which record Time of Arrival (ToA) and Time over Threshold (ToT) of the collected signal, respectively. In order to reduce the dead time, 180 channels are split into two separate parts and then the information in each part is read out by a data-driving priority readout scheme independently. Each channel has its own address encoded by an address encoder. The ToA, ToT and address of each channel are framed and encoded, and then transferred off chip with a serial speed of 4.4 Gbps.
Recent advances in lead-free based perovskite solar cells on optoelectronic properties, stability and economic feasibility
Authors: Chakraborty Kunal , Gupta Choudhury Mahua , Choudhury Sushabhan , Paul Samrat
Published: September 2022

The present review article represents the scope of different
lead (Pb)-free hybrid halide Perovskite solar cells (PSC) for
photovoltaic (PV) applications. Research on lead-free material is
emerging mainly to identify the alternatives of lead in the
Perovskite solar cells. Several homovalent (Sn2+, Ge2+,
Cu2+) and heterovalent (Sb3+, Bi3+, Ti4+)
materials have good physical properties to replace the lead content
in the absorbing material compound. However the power conversion
efficiency (PCE, %) is not higher as compared to lead based
material. This review article focuses on the characteristics,
material properties, stability and performance of the different
Pb-free materials as absorbing layer in the Perovskite solar cells.
SiPM and PMT driving, signals count, and peak detection circuits, suitable for particle detection
Authors: Fardipour Raki Gholamreza , Ghahremani Gol Maryam , Sahraei Mohammad , Khakzad Mohsen
Published: September 2022

The signals received from the optical receivers like SiPM
and PMT due to the collision of energetic particles with the
scintillators attached to these optical receivers are weak and
fast. Optimizing signals is necessary to measure the number of
signals and their peak height with electronic circuits. This text
presents an example of SiPM's driver circuit, signal counting, and
peak measurement. Also, the electronic circuits necessary to
optimize the signals, including amplification, removing background
noise, converting the signal to digital, and increasing the duration
of the signal, are presented in this text. In the end, we provide
two tests to confirm the correct operation of the circuits. Such a
system has several advantages. This set has a small volume and is
portable. Its operating voltage is 12 volts, with a current of about
0.3 amps; as a result, it is easily possible to use this set in any
experiment. In addition, the cost of building such a system is much
lower than providing similar ready-made designs. The most important
achievement here is to convert the standard signal taken from the
detector into an almost ideal optimized signal for signal counting
and peak measurement. Therefore, it seems that using all or part of
these circuits can be helpful for researchers. This text presents a
particular method for signal optimization and provides the reader
with a coherent and complete process of building and testing
circuits. If the reader is familiar with the basics of electronics
and detectors, they can reconstruct the circuits without any
problems. Therefore, parts of this text may have an educational and
review form.
Facile construction of tumour spheroids with induced M2 macrophage polarization for anticancer drug screening
Authors: Tran Na Ly , Lee In Kyu , Kim Hyerim , Lee Kangwon , Kim Sang-Heon , Oh Seung Ja
Published: September 2022

Tumour-associated macrophages (TAMs) are involved in cancer progression and drug resistance in the tumour microenvironment (TME). Consequently, macrophages as therapeutic targets have garnered increased attention; however, there are hurdles to screening interactions between cancer and macrophages owing to technical difficulties in recapitulating in vitro physiological systems. In this study, we propose a simple strategy to construct tumour spheroids with induced M2 macrophage polarization for anticancer drug screening. We observed that cytokine expression related to the TME in three-dimensional (3D) cancer spheroids was enhanced compared with that in two-dimensional conventional cancer cell cultures. We also demonstrated that the 3D breast tumour spheroids promote M2-like TAM polarization via granulocyte–macrophage colony-stimulating factor and granulocyte colony-stimulating factor. Furthermore, adipose tissue-derived stem cells, an abundant stromal cell population in the breast cancer TME, further enhanced the M2 phenotype in the in vitro tumour spheroids. Therefore, we propose the tumour spheroids as a drug screening platform to evaluate drug efficacy in cancers. Overall, the simple strategy to form tumour spheroids developed in this study will broaden the understanding of communication between cancer cells and macrophages and contribute to the evaluation of cancers and the development of better strategies for their therapy and management.
Soil coarsening alleviates precipitation constraint on vegetation growth in global drylands
Authors: Zhu Xinrong , Liu Hongyan , Xu Chongyang , Wu Lu , Shi Liang , Liu Feng
Published: September 2022

Drought is an important and complicated topic, and the specific variables that are considered to represent climate drought stress and plant water stress often generate highly contradictory conclusions. As the junction of the atmosphere and the biosphere, soil may play an important role in separating climatic drought stress from vegetation water constraint. Here, we conduct a comprehensive evaluation of water constraint on vegetation growth in global drylands by separating precipitation constraint and soil moisture constraint. Although global drylands are characterized by low precipitation supply capacity, there are indeed a large number of grids showing decoupled water availability for plants from variability of precipitation, with ratios of 47%, 64%, and 61% for arid, semiarid, and subhumid regions, respectively. Soil properties, instead of climate and root length regimes, can explain the water constraint divergence between precipitation and soil moisture. Sand content emerges as the most significant soil property to weaken the precipitation constraint on vegetation growth, with a 1% increase in sand content of global arid, semiarid, and dry subhumid regions increasing an average of 0.31, 0.45, and 0.04 gC m−2 yr−1 gross primary productivity (GPP) deviation from the theoretical GPP determined by precipitation, respectively. This study provides new insight into how soil texture interacts with precipitation constraints to influence plant-available water in global drylands, which contributes to assessing ecological drought in global drylands.
Unified thermodynamic–kinetic uncertainty relation
Authors: Vo Van Tuan , Van Vu Tan , Hasegawa Yoshihiko
Published: September 2022

Understanding current fluctuations is of fundamental importance and paves the way for the development of practical applications. According to the thermodynamic and kinetic uncertainty relations, the precision of currents can be constrained solely by the total entropy production or dynamical activity. In this study, we derive a tighter bound on the precision of currents in terms of both thermodynamic and kinetic quantities, demonstrating that these quantities jointly constrain current fluctuations. The thermodynamic and kinetic uncertainty relations become particular cases of our result in asymptotic limits. Intriguingly, the unified thermodynamic–kinetic uncertainty relation leads to a tighter classical speed limit, refining the time constraint on the system’s state transformation. The proposed framework can be extended to apply to state observables and systems with unidirectional transitions, thereby providing a constraint on the precision of the first-passage time.
Design of groundwater monitoring network for coastal aquifers based on seawater intrusion vulnerability: A case study of Mandaue City, Philippines
Authors: Condor B , Patiño C , Sinogaya J
Published: September 2022

Groundwater is an essential source of freshwater. However, this natural resource exhibits high vulnerability to contamination due to human activities and natural phenomena. Over extraction of groundwater and sea level rise have hastened seawater intrusion in aquifers that lie along the coasts. This has led to the accelerated deterioration of groundwater quality in coastal aquifers. Thus, there is an urgent need to develop tools to monitor groundwater resources. In this study, a framework of selecting priority areas for monitoring was applied to Mandaue City, Philippines. The monitoring areas were selected based on their vulnerability to seawater intrusion using the GALDIT-index. A collection of 77 initial public sites were investigated as potential locations of monitoring wells. The resulting network determined 45 priority areas located across the study area wherein monitoring wells should be located for the long-term observation of groundwater quality. These sites are composed of 28 from the initially investigated locations and 17 proposed sites which were determined to satisfy the required number of wells lacking in certain areas. The results of this study are intended to aid decision makers in creating groundwater management plans.
Green energy and environmental sustainability on Vernacular Architecture. The case of Ayllus of Atacama Desert and stilt houses of Chiloé
Authors: Pareti Stefania , Valdebenito Vicente , Rudolph Loreto , Bustamante Claudia
Published: September 2022

The main objective of this study is to explore the development of vernacular techniques capable of facilitate a green and sustainable architecture today’s. An ayllu in San Pedro de Atacama and a stilt house in Chiloé are selected as a comparative case, since (1) both are part of the vernacular architecture of its respective place, (3) both cases belong to extreme regions of the country, with both geographical characteristics totally opposite, the ayllu in the extreme north with a desert climate and the stilt houses in the country’s south with low temperatures and maritime-rainy climate, (4) both cases are works of green and sustainable architecture, wooden on stilt houses and adobe on ayllu. The methodology is carried out through three points, contamination levels (1), materiality (2) and energetic design and climate adaptation (3). It is concluded that the development of particular vernacular architecture, can introduce new logics to develop green energy and being closer to environmental sustainability, as has occurred in the palafitos and in the ayllu.
An approach for analysis of critical infrastructure vulnerability to climate hazards
Authors: Zlateva P , Hadjitodorov S
Published: September 2022

In recent years, climate change negatively impacts on the resilience of critical infrastructure. This increases the vulnerability of critical infrastructure to climate hazards. In this paper is proposed an approach for analysis of the critical infrastructure vulnerability to climate hazards. It is assumed that the level of vulnerability of the critical infrastructure depends on its levels of sensitivity and exposure to the specific climate hazards in the given geographical region. The approach is consisted from seven steps. For each of the variables related to the vulnerability, four levels are defined (Low, Middle, High, Very high). The usefulness and peculiarities of the proposed approach for analysis of critical infrastructure vulnerability to climate hazards are demonstrated with several examples. The results obtained with the proposed approach for vulnerability analysis can successfully help the stakeholders to make informed decisions about the choice of targeted measures to adapt critical infrastructure to climate change.
Sustainable product development of biomass briquette from Samanea saman leaf waste with rejected papaya as the binding agent in Indonesia
Authors: Hilario Yusuf , Sahputra Iwan Halim , Tanoto Yusak , Jeremy Gotama Gabriel , Billy Alexander , Anggono Willyanto
Published: September 2022

The depletion of solid fuels in the world triggers the requirement for the existence of an alternative fuel product as a substitute. In several studies, briquettes have become one of the alternatives used to deal with this problem. However, the selection of briquette material that considers its impact on economic, social, and environmental aspects has not been widely carried out. To solve this problem, the selection of raw materials for briquettes must be determined using the concept of sustainable product development (SPD). SPD is a concept that can be used to determine a new product by considering various aspects, including economic, environmental, and social aspects. Briquette fuel that is derived from leaf waste and rejected fruit as a binding agent can be an alternative to renewable solid fuels since the raw materials come from wastes that have no selling value. The methodology used in this research is by conducting a survey at five markets in Surabaya and proceeding with interviews with the local government official. Pugh Matrix Concept Selection (PMCS) method is used to determine the suitable raw materials and to analyze the sustainability of the product development. Through PMCS, the results show that the best material for briquette production based on economic, social, and environmental aspects is a mixture of Samanea saman leaf waste with a 12.83 rating value and rejected papaya as the binding agent with a 10.44 rating value. Briquette with a mixture of 95% Samanea saman leaf waste and 5% rejected papaya is produced with a mesh size of 60 or 250 μm and a compression pressure of 2 MPa and is identified to have a heating value of 4025.87 Kcal/Kg.
Predicting sunlight availability for vertical shelves using simulation
Authors: Man Ar , Chaichana Chatchawan , Wicharuck Suwimon , Rinchumphu Damrongsak
Published: September 2022

Vertical farming (VF) allows for a higher number of plants to be grown in a limited land area, maximizing agricultural land use. VF employs multiple vertical shelves. Each shelf consists of several levels. This paper aims to develop a computer simulation model. The computer model could predict the sunlight availability received at each level of the shelves. The model was developed using RHINO (RHINOCEROS) software with Grasshopper plug-in. The VF shelf was constructed for the experiment in Chiang Mai, Thailand. The experiment data is used to validate the computer model. The validated computer simulation model is then used to predict the daily averaged Photosynthetic Photon Flux Density (PPFD) received by each level of vertical shelves. Year-round daily averaged PPFD provides insights into the seasonal variations of sunlight availability. For the VF shelf constructed for experiment in Chiang Mai, it was found that the top level of the shelf would receive a yearly average of 1275.17 PPFD. The middle and bottom would receive 781.29 and 617.67 PPFD, respectively. The month with the lowest amount of sunlight is in January. This computer simulation model will help predict solar radiation received by each vertical farming shelf. The farmers could identify suitable shelf designs to provide enough PPFD for specific crops to be grown.