bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on fast identification model of water-flooded layer in old oilfield-- Taking Xingbei area of Daqing Oilfield as an example
Authors: Shang Xiaoyu
Published: October 2022

After long-term water flooding development in old oilfields, oil layers are generally flooded. Accurate and rapid recognize the water flooding layer is the key to later infill well layout and development plan adjustment. In this paper, taking Xingbei area of Daqing Oilfield as an example, on the basis of clarifying the characteristics of the water-flooded layer curve, through logging curve optimization, data preprocessing and algorithm model optimization processes, a rapid identification model of water-flooded layer suitable for this block is established. The results show that the HAC, CAL, RLLS and RMG curves with hidden duplicate information can be removed through the correlation screening of logging curves and the importance score of the tree model, which can reduce the amount of data calculation. When the four algorithms are used to identify the flooding level of each layer, the recognition rate of the XGboost algorithm can reach up to 95.45%; the reliability of this result has been confirmed in the model verification process (87.89%), which further shows that the model can be used to identify Xingbei area flooded.
Research on the Application of Computer Vision Technology in Power System UAV Line Inspection
Authors: Cheng Xuchang
Published: October 2022

The stability of transmission lines is one of the important factors to ensure stable power supply. In this paper, a set of UAV intelligent power line inspection flight control system is designed according to the special flight requirements of UAV in power line inspection operation based on the principle of photogrammetry. The key technologies of the system include UAV flight attitude control, high-precision time synchronization between multiple sensors, defect detection and intelligent diagnosis, airborne sensor calibration, wireless communication, and ground data processing. In this paper, a camera and an on-board computer are innovatively used for real-time image processing and pattern recognition for wire feature acquisition. At the same time, this paper proposes an improved Canny edge detection algorithm combined with image segmentation technology to achieve wire feature extraction and identification. The field test results show that the system can complete the remote control of the UAV and realize the intelligent navigation and inspection of the transmission line UAV.
Performance test of optimal denitration efficiency of a 350MW unit under the background of new power system
Authors: Zhong Ziwei , Zhu Lingkai , Zheng Wei , Gong Zhiqiang , Shang Panfeng , Guo Junshan , Liu Jun , Zhang Yanpeng
Published: October 2022

With the establishment of the goal of “carbon peaking and carbon neutralization”, a new power system based on new energy is proposed. With the rapid development of ultra-high voltage external power and new energy in Shandong power grid, the difficulty of system peak regulation is increasing. At present, the peak regulation is mainly based on direct regulating thermal power units. The capacity of pumped storage power stations is limited and there are no gas-fired generating units, which also leads to serious shortage of other flexible regulation resources that Shandong power grid can call. In 2022, Shandong Province plans to implement the renewable energy multiplication plan, and it is expected that the installed capacity of new energy will account for 38%. With the large-scale access of new energy, the “double high” characteristics of the power system are highlighted, and the technical characteristics and stability mechanism of the power grid will undergo profound changes. In the new power system with new energy as the main body, the role of thermal power generation has gradually changed from the electric power source to the regulating power source. Under the variable load conditions, find the optimal efficiency conditions and provide necessary data for the optimal denitration efficiency operation.
Construction of dual-carbon goal realization path based on fractal theory
Authors: Chi Hai , Wang Xincheng
Published: October 2022

The amount of CO2 emissions is related to people’s life, social progress and national development. To seek a balance between environmental protection and social progress is a problem that scholars have paid close attention to. This paper firstly studies the data of carbon emissions from 1997 to 2019, and conducts relevant processing on the data. Using fractal theory to predict the processed data, the prediction results show that my country’s carbon emissions will continue to grow. Finally, corresponding countermeasures are put forward for the realization of the dual-carbon goal.
New Progress in the Study of Siliceous Rock Oil and Gas in Nadanha Single Terrain
Authors: Qu Guohui , Tian Xuebin , Li Bowen , Li Xiunan , Zhang Zilu , He Weizhong , Liu Yikun , Bai Mingxing , Xie Kun
Published: October 2022

The siliceous shale oil and gas in Nadanhada terrane has been studied through field geological survey, geochemistry and sedimentary petrology. The results show that the area belongs to a good shale reservoir, and the siliceous rock is brittle and suitable for exploitation. The abundance of organic matter is relatively high. From west to east and from south to north, the abundance of organic matter increases and the maturity of organic matter decreases. From west to east and from south to north, the dynamic metamorphism and thermal contact metamorphism of the siliceous rocks in the Nadanhada terrane are gradually weakened, and the folds and magmatic intrusion of the strata are alleviated.
Can the Dragon Make the Lion Breathe Fire? The Links of Chinese Entrepreneurs in the Addis Ababa Economy
Authors: van Boekel Titus , Schutjens Veronique , Zoomers Annelies
Published: October 2022

China’s increasing role in many African economies has given rise to discussions about the drivers of these economic relations and the benefits that Africa can reap. This article, based on field work carried out in Addis Ababa (Ethiopia), aims to contribute to this discussion by shedding light on a group that is often overlooked: the Chinese small entrepreneurs. Our investigation of five specific economic linkages shows how Chinese entrepreneurs mainly operate in secluded market segments, but also are impactful players in the local economy of Bole Rwanda (Addis Ababa). Their presence has both direct and indirect economic effects: even though focusing mainly on serving the Chinese community, these entrepreneurs play important roles in employment generation, and the transfer of knowledge of particular markets, while simultaneously offering new opportunities for Ethiopian entrepreneurs and transforming the existing vegetable market. The dragon helped the lion to breathe fire—the challenge is to make it a far-reaching and long-lasting breath.
The Vacuum Cherenkov Detector (VCD) for γ-ray measurements in inertial confinement fusion experiments
Authors: Jeet J. , Zylstra A. B. , Rekow V. , Hardy C. M. , Pelepchan N. , Eckart M. , Kim Y. , Rubery M. , Moore A. S. , Schlossberg D. J. , Folsom E.
Published: October 2022

Inertial confinement fusion experiments at both the National Ignition Facility (NIF) and the Laboratory for Laser Energetics OMEGA laser facility currently utilize Cherenkov detectors, with fused silica as the Cherenkov medium. At the NIF, the Quartz Cherenkov Detectors improve the precision of neutron time-of-flight measurements; and at OMEGA, the Diagnostic for Areal Density provides measurements of capsule shell areal densities. An inherent property of fused silica is the radiator’s relatively low energy threshold for Cherenkov photon production (Ethreshold < 1 MeV), making it advantageous over gas-based Cherenkov detectors for experiments requiring low-energy γ detection. The Vacuum Cherenkov Detector (VCD) has been specifically designed for efficient detection of low energy γ’s. Its primary use is in implosion experiments, which will study reactions relevant to stellar and big-bang nucleosynthesis, such as T(4He,γ)7Li, 4He(3He,γ)7Be, and 12C(p,γ)13N. The VCD is compatible with LLE’s standard Ten-Inch Manipulator diagnostic insertion module. This work will outline the design and characterization of the VCD as well as provide results from recent experiments conducted at the OMEGA laser facility.
Boundary dynamics of a non-smooth memristive Hindmarsh–Rose neuron system
Authors: Min Fuhong , Rui Zhi
Published: October 2022

In this paper, the complex dynamics of non-smooth Hindmarsh–Rose (HR) neuron system with local active memristors is discussed through the theory of discontinuous dynamical system. Six mapping structures through two boundaries are employed to illustrate the various switching behaviors of the system. The analytical conditions of the HR system for the switching motions, such as passable motion and grazing motion, are investigated, and the extreme multistability of the improved HR neuron is revealed through switching bifurcations, parameter maps, and attraction basins. The firing activities of various modes in the HR system and the coexistence of various firing behaviors are observed by changing the initial values. Furthermore, the hardware circuit implement of the HR system is established to validate the numerical results.
DNA fragmentation in a steady shear flow
Authors: Qiao Yiming , Ma Zixue , Onyango Clive , Cheng Xiang , Dorfman Kevin D.
Published: October 2022

We have determined the susceptibility of T4 DNA (166 kilobase pairs, kbp) to fragmentation under steady shear in a cone-and-plate rheometer. After shearing for at least 30 min at a shear rate of 6000s−1, corresponding to a Reynolds number of O(103) and a Weissenberg number of O(103), 97.9±1.3% of the sample is broken into a polydisperse mixture with a number-averaged molecular weight of 62.6±3.2 kbp and a polydispersity index of 1.29±0.03, as measured by pulsed-field gel electrophoresis (with a 95% confidence interval). The molecular weight distributions observed here from a shear flow are similar to those produced by a (dominantly extensional) sink flow of DNA and are qualitatively different than the midpoint scission observed in simple extensional flow. Given the inability of shear flow to produce a sharp coil–stretch transition, the data presented here support a model where polymers can be fragmented in flow without complete extension. These results further indicate that DNA fragmentation by shear is unlikely to be a significant issue in microfluidic devices, and anomalous molecular weight observations in experiments are due to DNA processing prior to observation in the device.
Synchronizing the helicity of Rayleigh–Bénard convection by a tide-like electromagnetic forcing
Authors: Jüstel Peter , Röhrborn Sebastian , Eckert Sven , Galindo Vladimir , Gundrum Thomas , Stepanov Rodion , Stefani Frank
Published: October 2022

We present results on the synchronization of the helicity in a liquid-metal Rayleigh–Bénard experiment under the influence of a tide-like electromagnetic forcing with azimuthal wavenumber m = 2. We show that for a critical forcing strength the typical large-scale circulation in the cylindrical vessel of aspect ratio unity is entrained by the period of the tide-like forcing, leading to synchronized helicity oscillations with opposite signs in two half-spaces. The obtained experimental results are consistent with and supported by numerical simulations. A similar entrainment mechanism for the helicity in the solar tachocline may be responsible for the astonishing synchronization of the solar dynamo by the 11.07-year triple synodic alignment cycle of the tidally dominant planets Venus, Earth, and Jupiter.
A simple structured solar selective absorber for application in thermoelectric energy harvesters
Authors: Singh Harmeet Kaur Gurbachan , Matsumoto Kazuki , Sakurai Atsushi
Published: October 2022

This study focuses on green energy harvesting that aims to supply electricity from a different energy source: solar thermoelectric, which is present in the environment without grid connection or utilization of batteries. The concept of using solar selective absorbers and heat sinks is introduced to create temperature differences, which are then converted into electrical energy via the use of a thermoelectric power generator. The solar selective absorber used in this study is a light-absorbing material, and its voltage generation is then compared to a blackbody.
Invited papers from the PV Technologies for Desert Climates Workshop
Authors: Bermudez Veronica
Published: October 2022

Arid areas account for more than 20% of Earth's surface. Many of these arid areas suffer from harsh climates where energy consumption is high and production coexists with high hydrological stresses. In such areas, the production of water is directly linked to the production of electricity, bringing the Energy–Water nexus to a higher level [Heggy et al., Sustainable Energy-Water-Environment Nexus in Deserts (Springer, 2022)]. Under the current energy transition from a fossil-based economy to a renewable energy-based system, arid areas are seen as potential reservoirs for electricity production due to their high solar potential, thereby helping to achieve global decarbonation targets. This energy production transition will strongly affect the Energy–Water nexus as it will contribute to the decoupling of electricity from water production. The International Conference on Sustainable Energy–Water–Environment Nexus 2019 (ICSEWEN19) conference was the first to address the Sustainable Energy–Water Nexus in Deserts, bridging the gap between research and industry and highlighting the research capabilities relevant to Qatar, the region, and internationally. The Invited Papers from the International Conference on Sustainability, Energy, Water, and Environment Nexus in Desert Climates Special Collection in Journal of Renewable and Sustainable Energy presents articles covering the main elements of the conference with respect to solar photovoltaic implementation in desert environments as a key element to succeed in this global energy transition.
Suppression resources and their influence on containment of forest fires in Victoria
Authors: Marshall Erica , Dorph Annalie , Holyland Brendan , Filkov Alex , Penman Trent D.
Published: October 2022

Background Wildfire suppression is becoming more costly and dangerous as the scale and severity of impacts from fires increase under climate change. Aims We aim to identify the key environmental and management variables influencing containment probability for forest fires in Victoria and determine how these change over time. Methods We developed Random Forest models to identify variables driving fire containment within the first 24 h of response. We used a database of ~12 000 incident records collected across Victoria, Australia. Key results Response time, fire size at first attack, number of ground resources deployed (e.g. fire fighters), ignition cause, and environmental factors that influence fire spread (e.g. elevation, humidity, wind, and fuel hazard) were key drivers of suppression success within the first 24 h. However, certainty about the factors influencing suppression reduced as the containment period increased. Conclusions Suppression success hinges on a balance between the environmental factors that drive fire spread and the rapid deployment of sufficient resources to limit fire perimeter growth. Implications Decreasing the period between an ignition and the time of arrival at the fire will allow first responders to begin suppression before the fire size has exceeded their capability to construct a control line.
Interpretación semántica de verbos frasales por aprendientes de inglés como segunda lengua a partir de la posición
(dis)continua de sus partículas
Authors: Rincón Hernández Itsel Merari
Published: October 2022

Es investigación buscó establecer si los hablantes adultos no nativos de inglés interpretan los verbos frasales
aspectuales a partir de la posición continua o discontinua de la partícula que los acompaña y si esto tiene relación con su nivel
de dominio de inglés como segunda lengua (L2). Se diseñó una tarea de selección de imágenes que fue aplicada a hablantes adultos
nativos y no nativos de inglés, estos últimos fueron divididos en cuatro grupos a partir de sus horas de exposición a la lengua
meta (100–200 h, 300–400 h, 600–700 h, +1000 h). Los resultados sugieren que la posición de partícula puede afectar ocasionalmente
la interpretación de los verbos frasales de inglés por parte de hablantes no nativos; sin embargo, esto no ocurre de igual manera
en todos los verbos frasales, ya que la interpretación está también ligada a la categoría semántica de los verbos frasales y a la
partícula presente en cada verbo frasal. Finalmente, los hablantes no nativos de inglés con mayor número de horas de exposición a
la lengua meta tienen un desempeño no significativamente diferente al de los hablantes no nativos en la interpretación de verbos
frasales, aunque en algunos casos las diferencias son pronunciadas.
Metabolic features of innate lymphoid cells
Authors: Yu Huiyang , Jacquelot Nicolas , Belz Gabrielle T.
Published: October 2022

Innate and adaptive immune cells are found in distinct tissue niches where they orchestrate immune responses. This requires intrinsic and temporal metabolic adaptability to coordinately activate the immune response cascade. Dysregulation of this program is a key feature of immunosuppression. Direct or indirect metabolic immune cell reprogramming may offer new approaches to modulate immune cells behavior for therapy to overcome dysregulation. In this review, we explored how metabolism regulates lymphocytes beyond the classical T cell subsets. We focus on the innate lymphoid cell (ILC) family, highlighting the distinct metabolic characteristics of these cells, the impact of environmental factors, and the receptors that could alter immune cell functions through manipulation of metabolic pathways to potentially prevent or treat various diseases.
On the correlation between the TiN thin film properties and the energy flux of neutral sputtered atoms in direct current magnetron discharge
Authors: El Farsy Abderzak , Pierson Jean-François , Gries Thomas , de Poucques Ludovic , Bougdira Jamal
Published: October 2022

In this study, the energy flux of sputtered atoms on a substrate was correlated to the properties of titanium nitride (TiN) films deposited using direct current magnetron sputtering (dcMS) under mixed Ar and N2 atmospheres. The neutral titanium sputtered atoms velocity distribution functions (AVDFs) were measured by tunable diode-laser induced fluorescence (TD-LIF), and the flux of particles and their energy were derived. Mass spectrometry was used to characterize the energy-resolved flux of the ions. It was found that the neutral sputtered atoms flux and deposition rate were in good agreement, indicating that the flux of the neutral titanium ground state represents the number of deposited atoms. Moreover, TiN films were deposited at different gas pressures and at various Ar/N2 gas mixtures close to the conditions where stoichiometric TiN was formed, without bias voltage and heating of the substrates. The energy flux of the sputtered neutral Ti into the substrate was calculated from TD-LIF measurements. At a relatively low magnetron discharge pressure of 0.4 Pa, we demonstrated that the energy of sputtered neutral Ti impinging on the substrate is higher than the energy flux of ionized particles corresponding mainly to Ar+. Thus, the influence of the energy flux of the sputtered atoms on the texture and microstructure of the films is revealed. The (200) texture was obtained at 0.4 Pa when the energy flux of the sputtered atoms was higher than the ion energy flux. At 1.3 Pa where the sputtered atoms energy flux is one order lower compared to 0.4 Pa the (111) texture was obtained. The high-energy flux of the ground state of Ti sputtered atoms seems to allow stress removal in the films.
Machine learning interatomic potentials for aluminium: application to solidification phenomena
Authors: Jakse Noel , Sandberg Johannes , Granz Leon F , Saliou Anthony , Jarry Philippe , Devijver Emilie , Voigtmann Thomas , Horbach Jürgen , Meyer Andreas
Published: October 2022

In studying solidification process by simulations on the atomic scale, the modeling of crystal nucleation or amorphization requires the construction of interatomic interactions that are able to reproduce the properties of both the solid and the liquid states. Taking into account rare nucleation events or structural relaxation under deep undercooling conditions requires much larger length scales and longer time scales than those achievable by ab initio molecular dynamics (AIMD). This problem is addressed by means of classical molecular dynamics simulations using a well established high dimensional neural network potential trained on a set of configurations generated by AIMD relevant for solidification phenomena. Our dataset contains various crystalline structures and liquid states at different pressures, including their time fluctuations in a wide range of temperatures. Applied to elemental aluminium, the resulting potential is shown to be efficient to reproduce the basic structural, dynamics and thermodynamic quantities in the liquid and undercooled states. Early stages of crystallization are further investigated on a much larger scale with one million atoms, allowing us to unravel features of the homogeneous nucleation mechanisms in the fcc phase at ambient pressure as well as in the bcc phase at high pressure with unprecedented accuracy close to the ab initio one. In both cases, a single step nucleation process is observed.
Exploring the 4d1 analogue of cuprates: theoretical studies on bulk NbF4 and NbF4 monolayer stabilized on MgO (001) plane
Authors: Yang Yang , Wang Qiang-Hua
Published: October 2022

The recent research in infinite-layer nickelates has inspired new effort in finding the cuprate analogs. Here we propose that NbF4, which contains niobium-centered fluorine octahedra, is a promising 4d
1 analogue of cuprates. Using the density functional theory, we first show that bulk NbF4 is in close proximity to d
1 configuration, with Nb

4

d

x
y

orbital nearly half-filled. A single band with dominating

4

d

x
y

character crosses the Fermi level, forming a square-like Fermi surface. The intralayer G-type antiferromagnetic (AFM) order is energetically favored and the Coulomb interaction drives the system into an AFM insulator. Next we demonstrate that the NbF4 layer can be stabilized on MgO substrate with main electronic and magnetic features retained, offering an alternative route to realize the NbF4-related high-T

c
superconductors. Furthermore, we derive effective single orbital models for both systems and investigate the electron correlation effects via functional renormalization group. We find that the G-type AFM dominates near half-filling but

d

x
2

−

y
2

-wave superconductivity (SC) prevails upon suitable hole/electron doping. Based on the striking similarities between NbF4 and cuprates, we suggest that NbF4-related compounds may be exotic candidates for searching new high-T

c
superconductors.
Stability of nontrivial magnetic structures in ferromagnetic films with antidots
Authors: Magadeev E B , Vakhitov R M , Kanbekov R R
Published: October 2022

The paper investigates stability conditions of vortex-like inhomogeneities in perforated ferromagnet films with strong uniaxial anisotropy of the ‘easy plane’ type. It has been demonstrated that the non-trivial magnetic structures, which are characterized by the absence of an exit of the magnetization vector from the film’s plane, can be observed at the absolute values of the anisotropy constant which exceed a certain threshold point. Possible methods (analytical, numeric, and empiric) have been developed to calculate this threshold value. Universally applicable estimates have been obtained of the minimum permissible value of the anisotropy constant for a number of the most important cases. Possible scenarios have been investigated for a loss of stability of the magnetic structure as the film’s material parameters vary.
Enhanced cataluminescence sensing of MIL-53(Al)/Sb2SnO5 composites for isobutanol detection
Authors: Zhang Qianchun , Zhou Qin , Wu Yun , Li Yanxin , Tian Fengling , Tang Shan , Jiang Li
Published: October 2022

In this study, MIL-53(Al) and Sb2SnO5 were synthesized by hydrothermal and precipitation methods, respectively. The doped MIL-53(Al)/Sb2SnO5 showed excellent catalytic properties, specifically for selectivity and sensitivity for isobutanol (IBN). To assess the catalytic properties of MIL-53(Al)/Sb2SnO5, an IBN gas sensor based on cataluminescence of MIL-53(Al)/Sb2SnO5 was developed, and it demonstrated detection of IBN with high sensitivity, high specificity, fast detection, and good stability. The signal response and recovery time of IBN gas sensor were 0.5 s and 6 s, respectively, and a good linear relation was 0.050–2.5 μg ml−1 (R
2 = 0.9956) with a low detection limit of 0.015 μg ml−1. Further, the IBN sensor applied in the detection of real samples had satisfactory recoveries (90.0%–108%) with relative standard deviations of 3.2%–6.7%. The developed sensor based on MIL-53(Al)/Sb2SnO5 has great prospects for the practical detection of IBN gas in the fields of environmental analysis, safety monitoring, etc.
A high throughput rapid scanning dispersive spectrometer for longwave infrared absorption spectroscopy
Authors: Butler Austin , Krier Herman , Glumac Nick
Published: October 2022

A rapid-scanning spectrometer was constructed to capture several hundred wavenumber wide spectral scans at greater than 1 kHz repetition rate in the longwave infrared. The system, made from commercial-off-the-shelf components, exceeds scan width and repetition rate limitations present in other infrared diagnostics while maintaining better than 10 cm−1 spectral resolution through its high throughput (f/2) design. Instrument design and construction is discussed in detail, and validation of the spectrometer’s ability to capture time resolved spectra in the 800–1400 cm−1 region at 1.2 kHz was demonstrated through the measurement of organophosphorus chemical nerve agent simulant destruction inside high explosive fireballs.
Modelling and design of low-power, non-conventional current sensors based on smart materials for high-voltage transmission lines
Authors: Nikolic B , Khan S H
Published: October 2022

This paper presents a new technique for measurement of current based on magnetic shape memory (MSM) smart alloys. MSM alloys undergo shape changes when exposed to magnetic fields. The non-conventional instrument transformer (NCIT) proposed in this paper utilises this property to measure current. There is a correlation between the magnetic field produced by a current and the shape change of an MSM material (MSM sensor). By exploiting this correlation, we have shown that it is possible to measure alternating currents (a.c.) in high voltage overhead transmission lines. A change in the length of the MSM element causes voltage output in a linear variable differential transducer. The design of the NCIT was optimised for transmission lines. Several designs of its magnetic circuit were simulated using finite element package ANSYS APDL. Several key parameters were investigated to evaluate their effects on the sensitivity of the NCIT. Results are presented as the relationship between the current in the conductor and strain (linear elongation) of the MSM element. A commonly used conductor in high-voltage transmission lines was modelled together with the MSM element and the magnetic circuit. Recommendations have been made on the design of NCITs considering various parameters. In addition, analyses of errors in ANSYS models for the magnetic circuit have been presented. The developed methodology and obtained results are verified by comparing them to the results obtained through an experiment done by a manufacturer of MSM materials.
Mixing effect in Zr–Cu metallic liquids
Authors: Luo Xianan , Kang Heng , Niu Xiaofeng , Qiao Junwei , Song Kaikai , Wang Weimin , Qin Jingyu , Pan Shaopeng
Published: October 2022

Understanding the mixing properties of liquids is important to design new materials; however, the mechanism of mixing effect is unclear. In this work, the mixing effect of Zr–Cu metallic liquids has been investigated via molecular dynamics simulations. Various mixing properties including mixing enthalpy, (ΔH
m) mixing volume (ΔV
m), mixing coordination number (ΔZ
m) and mixing diffusion coefficient (ΔD
m) are studied in this work. Remarkably, it is found that all the mixing properties (ΔP
m) can be described by a common equation, ΔP
m = [aP
(T) + bP
(T)* (c
Zr − c
Cu)]*c
Zr*c
Cu. In addition, it is found that all the fitting coefficients of aP
(T) and most of bP
(T) show a quadratic dependence of temperature. Moreover, it is found that ΔH
m, ΔV
m and ΔD
m show linear correlations with each other at high temperatures, revealing close correlation between the thermodynamic and dynamic properties in metallic liquids. Our results are helpful to understand the mixing effects in metallic liquids.
Design and implementation of knee-ankle exoskeleton for energy harvesting and walking assistance
Authors: Chen Bing , Zheng Chengwang , Zi Bin , Zhao Ping
Published: October 2022

The increasing requirement of powering portable electronic devices can be potentially met by recycling the biomechanical energy generated during the human joint motion through a knee-ankle exoskeleton. In this paper, a knee-ankle exoskeleton is designed to recycle the negative work from the wearer’s knee extension and ankle dorsiflexion. The exoskeleton can convert the mechanical energy into electrical energy for energy harvesting and assist the knee flexion and ankle plantarflexion to reduce the wearer’s metabolic cost during walking. It is mainly composed of two torsion springs, two one-way transmission mechanisms, a gear train, and a generator. The torsion springs can store the elastic energy when the wearer’s ankle and knee joints do negative work and release it to assist walking when positive work is required. The one-way transmission mechanisms are employed to filter the knee flexion and ankle plantarflexion and to convert the knee extension and ankle dorsiflexion into the one-way rotation of the generator by symmetrically arranging the gear train. Finally, experiments are conducted to evaluate the performance of the developed knee-ankle exoskeleton. The experimental results indicate that the exoskeleton can generate an average electrical power of 0.49 W and a maximum instantaneous electrical power of 1.8 W at a walking speed of 5.5 km h−1 during a gait cycle, and reductions of 3.48% ± 0.33%, 9.50% ± 0.29%, and 4.54% ± 0.47% of the average muscle activities of the semitendinosus, soleus, and gastrocnemius during a gait cycle are observed, respectively.
Comprehensive study on structure, shielding properties of Ga-In-Sn-Bi-Zn alloys: potential use for low energy radiation
Authors: Wu Jiale , Duan Yunbiao , Hu Jin , Zhai Youwen , Wang Zhiyi , Feng Yongjin , Zhao Ziqiang , Fan Hongtao , Zhang Weijun , Wang Kaijun
Published: October 2022

Low-melting point Ga-In-Sn-Bi-Zn alloys were prepared using a vacuum melting technique as a novel radiation shielding material. To evaluate the interaction between alloys and photons in the energy range of 1–10000 keV, the WinXCom and Phy-X procedures are used to determine the shielding parameters for the Ga-In-Sn-Bi-Zn alloys, such as the mass attenuation coefficient, linear attenuation coefficient, half-value layer, tenth-value layer, mean free path, effective atomic number. Simultaneously, the energy absorption and exposure buildup factors, fast neutron removal cross section values is also calculated and the comparative lead equivalent (M) and weight reduction over lead for the alloy samples are compared. It is observed that the Ga2In2Sn2Bi3Zn1 alloy have exhibit superior comprehensive radiation attenuation, with a weight reduction of 2.948% compared to lead for the same shielding performance in the 30–90 keV range. After being irradiated by 40 keV He + irradiation system for 120 h, the phase structure of Ga2In2Sn2Bi3Zn1 alloy remained unchanged and that it shows excellent radiation tolerance. Combined with field emission scanning electron microscopy, x-ray diffraction, differential scanning calorimetry and thermogravimetric analysis results indicate that Ga2In2Sn2Bi3Zn1 is a eutectic alloy with a five-phase complex-regular structure and a melting point of 66.95 °C. The alloy exhibits excellent fluid compliance in the molten state when blended with polymers to prepare composites. The alloy filler is uniformly and continuously distributed in the polymer matrix, which ensures the reliability of the radiation shielding properties of the composites.
Theoretical study of perovskite solar cell for enhancement of device performance using SCAPS-1D
Authors: Srivastava Pranjal , Sadanand  , Rai Shambhavi , Lohia Pooja , Dwivedi D K , Qasem Hussam , Umar Ahmad , Akbar Sheikh , Algadi Hassan , Baskoutas Sotirios
Published: October 2022

Perovskite solar cells are a pioneering photovoltaic technology that has significantly improved performance in current years. The fundamental n-i-p planar heterojunction structure of solar cells is structured and simulated in the present work. The device configuration Glass/ITO/WS2/CH3NH3PbI3/P3HT/Au was investigated using the Solar Cell Capacitance Simulator (SCAPS-1D) program. To increase the performance of the photovoltaic solar cell thickness, bandgap, doping concentration and temperature have been varied. Further, using the optimal value of the different parameters, the performance of the photo-voltaic device such as power conversion efficiency (PCE) and Fill Factor (FF) are obtained as 27.02%, and 85.44%, respectively. Also, Open-circuit Voltage (VOC) of 1.46 V and Short-circuit current density (JSC) of 21.56 mA cm−2 were achieved. The influence of donor concentrations has been studied by varying its value from 1 × 10−12 cm−3 to 1 × 10−20 cm−3 for the proposed device. Thus, using different charge transport materials, the power convergence efficiency of the perovskite solar cell has been enhanced. Our simulation study reveals that the proposed configuration could be used to fabricate a device for the improvement of the efficient perovskite solar cell.
Soliton solutions of the (2+1)-dimensional Nizhnik-Novikov-Veselov equation via the Lie symmetry method and its stability analysis by using bifurcation theory
Authors: Manju Kumari , Kumar Mukesh
Published: October 2022

The objective of the present article is to seek new explicit solutions to the (2+1)-dimensional Nizhnik-Novikov-Veselov(NNV) equation. The NNV system is highly nonlinear in nature and is a known isotropic Lax extension of the Korteweg–de Vries model. The similarity transformation method has been used to systematically reduce the NNV equation into ordinary differential equations(ODEs). The new exact solutions have been obtained by solving the obtained ODEs based on the formed relationships. The resulting soliton solutions contain some arbitrary constants and functions. The use of appropriate functions and constants highlighted that the solutions of the NNV equation might be soliton, multisoliton, parabolic, doubly soliton and trigonometric. Moreover, the stability of the corresponding dynamical system has been investigated using bifurcation theory with different parametric regions. The figures obtained during MATLAB simulation supported the dynamic features of the derived solutions. Finally, we explore incredible aspects of the exact wave solutions via phase portraits. The phase portraits validate the existence of some families of homoclinic and periodic orbits about the equilibrium points, respectively.
Decay constants of B

c
(nS) and

(nS)*
Authors: Sun Chao , Ni Ru-Hui , Chen Muyang
Published: October 2022

The decay constants of the low lying S-wave

mesons, i.e.

and

with

, are calculated in the nonrelativistic quark model. The running coupling of the strong interaction is taken into account, and the uncertainties due to varying parameters and losing Lorentz covariance are considered carefully. As a byproduct, the decay constants of the low lying S-wave charmonium and bottomium states are given in the appendixes.
Integration of high-performance spin-orbit torque MRAM devices by 200-mm-wafer manufacturing platform
Authors: Zhang Hongchao , Ma Xiangyue , Jiang Chuanpeng , Yin Jialiang , Lyu Shuqin , Lu Shiyang , Shang Xiantao , Man Bowen , Zhang Cong , Li Dandan , Li Shuhui , Chen Wenjing , Liu Hongxi , Wang Gefei , Cao Kaihua , Wang Zhaohao , Zhao Weisheng
Published: October 2022

We demonstrate in-plane field-free-switching spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices that are capable of low switching current density, fast speed, high reliability, and, most importantly, manufactured uniformly by the 200-mm-wafer platform. The performance of the devices is systematically studied, including their magnetic properties, switching behaviors, endurance and data retention. The successful integration of SOT devices within the 200-mm-wafer manufacturing platform provides a feasible way to industrialize SOT MRAMs. It is expected to obtain excellent performance of the devices by further optimizing the MTJ film stacks and the corresponding fabrication processes in the future.
Identification of subsurface damage of 4H-SiC wafers by combining photo-chemical etching and molten-alkali etching
Authors: Geng Wenhao , Yang Guang , Zhang Xuqing , Zhang Xi , Wang Yazhe , Song Lihui , Chen Penglei , Zhang Yiqiang , Pi Xiaodong , Yang Deren , Wang Rong
Published: October 2022

In this work, we propose to reveal the subsurface damage (SSD) of 4H-SiC wafers by photo-chemical etching and identify the nature of SSD by molten-alkali etching. Under UV illumination, SSD acts as a photoluminescence-black defect. The selective photo-chemical etching reveals SSD as the ridge-like defect. It is found that the ridge-like SSD is still crystalline 4H-SiC with lattice distortion. The molten-KOH etching of the 4H-SiC wafer with ridge-like SSD transforms the ridge-like SSD into groove lines, which are typical features of scratches. This means that the underlying scratches under mechanical stress give rise to the formation of SSD in 4H-SiC wafers. SSD is incorporated into 4H-SiC wafers during the lapping, rather than the chemical mechanical polishing (CMP).
Asymmetry variations in Arctic summer onset and ending: Role of sea-ice melting
Authors: Yang Xiaoye , Zeng Gang , Wang Wei-Chyung , Iyakaremye Vedaste , Zhang Shiyue
Published: October 2022

Previous studies found that in Arctic regions with severe sea ice melting, summer ending (SE) variations are significantly larger than summer onset (SO) variations in the past few decades. Based on short-term observations, researchers preliminarily suggested that radiation variations caused by an earlier melting onset could be the possible reason for asymmetric Arctic SO/ending variations (AASV). Based on observations and National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis I dataset, here we quantitatively characterize AASV by calculating the difference between the 11 year sliding trend of Arctic SO and SE. The results show that AASV positively correlates with sea ice melting in summer. The increased summer sea ice melting increases the area to absorb short-wave radiation in summer and then release more long-wave radiation to heat the lower atmosphere and delay the peak time of long-wave radiation releasing. The variations in radiation lead to a significant delay of the Arctic SE, with no significant variations in SO. We introduce CMIP6 historical and future simulations of 15 models to verify further the relationship between AASV and summer sea ice melting. Historical run reproduces the observed asymmetry, and future simulations under various warming levels show that AASV will vanish with disappeared melting variations or be strengthened with increased melting. The latter could delay freeze-up and further exacerbate the following years’ melting, which will enhance AASV. Furthermore, AASV will delay the onset and peak time of Arctic amplification.
Achieving SDGs 11: A Review on Neighbourhood Engagement in Local Authorities Towards Disaster Risk Reduction of Highland Developments in Selangor
Authors: Yahman Nurul Khalida , Sarkom Yazid , Muhamad Ariff Nor Rima
Published: October 2022

Selangor’s growing population and accelerating economic conditions have resulted in the demand for human settlements. As a result, Selangor development has encroached the highland areas and it was constantly hit with inundated landslide disasters. Landslides are now viewed not only as natural occurrences or as the result of design flaws, but as a greater risk to society that must be managed accordingly. Since then, the issue of neighbourhood engagement in local authorities has increased. There are four issues that affect neighbourhood engagement in local authorities, 1) People in urban areas spend more time in their workplaces, 2) Some of planning and development tools, planning standards, and regulations are not clear, 3) Limited community capacity in decision making, and 4) Government behaviour towards residents in highland areas. Improving neighbourhood engagement in local authorities significantly enhances disaster risk reduction of highland developments in Selangor. Local authority as the service provider plays an important role in this issue, especially when it relates to policy decision-making. The aim of this research is to establish neighbourhood engagement framework in local authorities towards disaster risk reduction of highland developments in Selangor as to achieve SDGs 11. To achieve the aim, this review has two (2) objectives: 1) To investigate factors affecting neighbourhood engagement in local authorities towards disaster risk reduction in highland developments and 2) To suggest strategies to improve the neighbourhood engagement in local authorities towards disaster risk reduction in highland developments. The finding of this desk study suggests that even though neighbourhood engagement is exercised by the Local Authorities during the planning stage of highland development, the practice should be continued until after the occupation of the properties to help reduce the risk of landslides and highland disasters.
Integration Method for Web based Visualization Framework of Green Highway Index and Carbon Footprint Calculator
Authors: Yousif Omar Sedeeq , Zakaria Rozana , Aminudin Eeydzah , Shamsuddin Siti Mazzuana , Abdul Rahman Mohammad Faiz , Gara Jawa , Ahmad Nadzrol Fadzilah
Published: October 2022

Global warming and the development of the green economy have imposed more pressure on government economies to de-carbonise their economic initiatives. This, along with the global financial crisis, has prompted a significant rethinking of digital solutions to monitor carbon emissions. Likewise, drawing investors’ investment to further development of green highways by digitised tools for infrastructure projects is crucial. However, there is a demand for integration and visualisation of green highways assessment tools, which highlights an important gap in developing data integration and web-based visualisation application. This paper presents a research proposal method to build an integrated web-based dashboard that monitors the green highway rating assessment and the Carbon Footprint. It emphasizes variables of Malaysia Green Highway Index (MyGHI) and Carbon Footprint Calculator (CFC). A framework for integrating and transforming towards visualisation of web-based dashboard is established. The integration of MyGHI-CFC to the digital level and create a web-based dashboard used different methodologies from mixed qualitative and quantitative research. The results of this integration and visualization foresee contribute to an effective example, paving researchers with effective tools and standards that will contribute to the development of the green highway and future sustainability projects.
Towards Sustainable Public Transportation Cost in Malaysia
Authors: Majid Rohayu Ab , Said Rosli , Sahray Kholim , Mustafar Suriyana , Kaspin Morni
Published: October 2022

Public transportation has been opted as the main mode of travelling between destinations among Malaysians rather than private transportation. Each of the two types of transportation has its own characteristics that can attract the attention of passengers. Between the two, the rate of transportation costs is becoming the main concern among passengers. Therefore, this study was conducted to justify the extent of transportation costs incurred by Malaysians and their relationship with the cost attributes. The study was conducted on public travelers who are potentially using the various types of available public transportation. Six (6) scales of transportation cost have been explored in this research. A total of 900 responses were obtained from respondents living within the Klang Valley. Data has been analysed by employing descriptive and inferential analysis. The results of the study show that MRT/ LRT/ Monorail has become the most popular transportation among the population. The total of RM400 transportation cost per month was found to be sustainable as a result of affordable fares and public transport rebates.
Energy Consumption in Open and Enclosed Layout of Shopping Malls in Malaysia
Authors: Yaman Rostam , Yaziz Nur Suzziana , Ismail Farrah Zuhaira , Ahmad Noraini
Published: October 2022

shopping mall requires a huge amount of energy, in terms of embodied and operational energy needed to operate/ This research aim is to investigate the total energy electricity usage based on different types of shopping mall design layout while understanding the awareness of end user toward the building characterizes pertinent to energy uses of shopping malls. This research was conducted at two low-rise shopping malls in Klang Valley. The field study was conducted to explore the building configuration including the size, building form, orientation and opening. The data were collected and analyzed in order to have better understanding of total energy usage in these case studies. The Building Energy Index (BEI) in the case studies was calculated and the results are be compared. The results of study find that the BEI for open building has lower value than enclosed building.
Formulating an Assessment Tool for the Implementation of Green Initiatives in Library
Authors: Ismail Farrah Zuhaira , Yaman Rostam , Razali Khairul Nazli
Published: October 2022

Amidst environmental crisis, the role of built environment sector becomes even more vital as it formed capacity in contributing a substantial factors to reduce energy usage and emission of greenhouse gas to atmosphere. Library specifically, act as crucial function in extending the agenda of promoting environmental practice. However, limited rating system explicitly for library’s green initiatives makes it challenging for library to implement these initiatives due to lack of proper guidelines. Hence, this study was conducted to examine existing checklists measuring green initiatives in library and to formulate assessment list for evaluating sustainable library’s operational initiatives. Systematic literature reviews were conducted in establishing the evaluation checklist, in which three existing checklists related to green initiatives in library were compared and referred to. The assessment checklist developed in this study identifies 107 initiatives related to facilities can be implemented by existing libraries in Malaysia. The result of this study serves as a basis for libraries in Malaysia to environmentally improve its facilities.