bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatiotemporal characteristics of spin transport in compensated metals with electron–hole exchange interaction
Authors: Sakai Masamichi , Aktar Mst Sanjida , Yoshizumi Toshihiro , Hasegawa Shigehiko
Published: October 2021

We develop a theory describing spatiotemporal behavior of spin transport in two-band metals by postulating a spin–exchange interaction between electrons and holes. Starting with the semiclassical Boltzmann equation, we derive a system of coupled diffusion equations and solve them analytically under steady-state conditions. The solutions reveal two types of electron–hole coupled-spin transport modes: a dissipative mode and a nondissipative mode with an infinite spin diffusion length. The two modes are the manifestations of two types of spin coupling channels. Besides the exchange interaction, we incorporate into our derivation the relaxation caused by the spin–orbit interaction to show how it affects the spin transport characteristics of the two modes.
Multi-channel monitoring data compression method for industrial robot based on compressed sensing
Authors: Yu Xiaojie , Hu Qiao , Xu Dan , Xie Xingju , Liu Yaohui
Published: October 2021

To address the problems of considerable redundancy and weak transmission security of multi-channel real-time vibration monitoring data of industrial robots, in this research a compressed sensing (CS)-based method to compress multi-channel industrial robot monitoring data has been proposed. Firstly, the multi-sensor data of the robot is fused into a comprehensive signal by the cross-correlation function fusion algorithm, which can significantly reduce the signal redundancy among sensors and improve the signal quality. Then, the discrete cosine transform matrix is used for sparse decomposition analysis of the synthetic signal. Finally, CS technology and chaotic matrix are used to encrypt and compress the integrated signal to achieve efficient encryption transmission. The experimental results show that the method can significantly reduce the amount of data transmitted and enhance the encryption performance during transmission without sacrificing helpful information and ensuring signal transmission efficiency and security.
High-efficiency diffraction gratings for EUV and soft x-rays using spin-on-carbon underlayers
Authors: Wang Xiaolong , Kazazis Dimitrios , Tseng Li-Ting , Robinson Alex P G , Ekinci Yasin
Published: October 2021

We report on the fabrication and characterization of high-resolution gratings with high efficiency in the extreme ultraviolet (EUV) and soft x-ray ranges using spin-on-carbon (SOC) underlayers. We demonstrate the fabrication of diffraction gratings down to 20 nm half-pitch (HP) on Si3N4 membranes with a bilayer of hydrogen silsesquioxane (HSQ) and spin-on-carbon and show their performance as a grating mask for extreme ultraviolet interference lithography (EUV-IL). High-resolution patterning of HSQ is possible only for thin films due to pattern collapse. The combination of this high-resolution resist with SOC circumvents this problem and enables the fabrication of high aspect ratio nanostructures. Rigorous coupled-wave analysis shows that the bilayer gratings exhibit higher diffraction efficiency than what is feasible with a grating made of HSQ. We also demonstrate a simple and accurate method to experimentally measure the diffraction efficiency of high-resolution gratings by measuring the relative ratio of the dose-to-clear curves of the photoresist. The measured diffraction efficiencies are in good agreement with the theoretically predicted values. Furthermore, we verify our calculations and measurements by printing line/space patterns in chemically amplified resists down to 10 nm HP with both HSQ and bilayer grating masks using EUV-IL. The improved diffraction efficiency of the bilayers is expected to have applications not only in gratings for interference lithography, but also in Fresnel zone plates and gratings for spectroscopy in the EUV and soft x-ray ranges.
Solvation of NiO
x
for hole transport layer deposition in perovskite solar cells
Authors: Armstrong Peter J , Chandrasekhar P S , Chapagain Sashil , Cline Carmen M , van Hest Maikel F A M , Druffel Thad , Grapperhaus Craig A
Published: October 2021

A series of nickel oxide (NiO
x
) inks, in the perovskite antisolvent chlorobenzene (CB) containing 15% ethanol, were prepared for the fabrication of p-i-n perovskite solar cells by blade coating. The inks included triethylamine (Et3N) and alkyl xanthate salts as ligands to disperse NiO
x
particle aggregates and stabilize suspension. A total of four inks were evaluated: 0X (Et3N with no alkyl xanthate), 4X (Et3N + potassium n-butyl xanthate), 12X (Et3N + potassium n-dodecyl xanthate), and 18X (Et3N + potassium n-octadecyl xanthate). The inks were characterized by UV–visible spectroscopy and FT-IR spectroscopy and the resulting films analyzed by thermogravimetry and scanning electron microscopy. Devices prepared using the 0X ink resulted in a peak power conversion efficiency (PCE) of 14.47% (0.25 cm2) and 9.96% (1 cm2). The 0X devices showed no significant loss of PCE after 100 days in a nitrogen flow box. Devices prepared with inks containing alkyl xanthate ligand had lower PCE that decreased with decreasing chain length, 18X > 12X > 4X.
Self-force on a charged particle in an external scalar field
Authors: Noble Adam , Burton David A , Docherty Lauren , Jaroszynski Dino A
Published: October 2021

A charged particle subject to strong external forces will accelerate, and so radiate energy, inducing a self-force. This phenomenon remains contentious, but advances in laser technology mean we will soon encounter regimes where a more complete understanding is essential. The terms ‘self-force’ and ‘radiation reaction’ are often used synonymously, but reflect different aspects of the recoil force. For a particle accelerating in an electromagnetic field, radiation reaction is usually the dominant self-force, but in a scalar field this is not the case, and the total effect of the self-force can be anti-frictional. Aspects of this self-force can be recast in terms of spacetime geometry, and this interpretation illuminates the long-standing enigma of a particle radiating while experiencing no self-force.
Sustained W-melting experiments on actively cooled ITER-like plasma facing unit in WEST
Authors: Corre Y , Grosjean A , Gunn J P , Krieger K , Ratynskaia S , Skalli-Fettachi O , Bourdelle C , Brezinsek S , Bruno V , Chanet N , Coenen J , Courtois X , Dejarnac R , Delmas E , Delpech L , Desgranges C , Diez M , Dubus L , Durif A , Ekedahl A , Fedorczak N , Firdaouss M , Gardarein J-L , Gaspar J , Gerardin J , Guillemaut C , Houry M , Loarer T , Maget P , Mandelbaum P , Mitteau R , Missirlian M , Moreau P , Nouailletas R , Nardon E , Pocheau C , Podolnik A , Reilhac P , Regal-Mezin X , Reux C , Richou M , Rigollet F , Schwob J-L , Thorén E , Tolias P , Tsitrone E
Published: October 2021

The consequences of tungsten (W) melting on divertor lifetime and plasma operation are high priority issues for ITER. Sustained and controlled W-melting experiment has been achieved for the first time in WEST on a poloidal sharp leading edge of an actively cooled ITER-like plasma facing unit (PFU). A series of dedicated high power steady state plasma discharges were performed to reach the melting point of tungsten. The leading edge was exposed to a parallel heat flux of about 100 MW.m−2 for up to 5 s providing a melt phase of about 2 s without noticeable impact of melting on plasma operation (radiated power and tungsten impurity content remained stable at constant input power) and no melt ejection were observed. The surface temperature of the MB was monitored by a high spatial resolution (0.1 mm/pixel) infrared camera viewing the melt zone from the top of the machine. The melting discharge was repeated three times resulting in about 6 s accumulated melting duration leading to material displacement from three similar pools. Cumulated on the overall sustained melting periods, this leads to excavation depth of about 230 μm followed by a re-solidified tungsten bump of 200 μm in the JxB direction.
Brain-computer interface-based assessment of color vision
Authors: Norton James J S , DiRisio Grace F , Carp Jonathan S , Norton Amanda E , Kochan Nicholas S , Wolpaw Jonathan R
Published: October 2021

Objective. Present methods for assessing color vision require the person’s active participation. Here we describe a brain-computer interface-based method for assessing color vision that does not require the person’s participation. Approach. This method uses steady-state visual evoked potentials to identify metamers—two light sources that have different spectral distributions but appear to the person to be the same color. Main results. We demonstrate that: minimization of the visual evoked potential elicited by two flickering light sources identifies the metamer; this approach can distinguish people with color-vision deficits from those with normal color vision; and this metamer-identification process can be automated. Significance. This new method has numerous potential clinical, scientific, and industrial applications.
Closed-loop control of neural spike rate of cultured neurons using a thermoplasmonics-based photothermal neural stimulation
Authors: An Yujin , Nam Yoonkey
Published: October 2021

Objective.Photothermal neural stimulation has been developed in a variety of interfaces as an alternative technology that can perturb neural activity. The demonstrations of these techniques have heavily relied on open-loop stimulation or complete suppression of neural activity. To extend the controllability of photothermal neural stimulation, combining it with a closed-loop system is required. In this work, we investigated whether photothermal suppression mechanism can be used in a closed-loop system to reliably modulate neural spike rate to non-zero setpoints.Approach. To incorporate the photothermal inhibition mechanism into the neural feedback system, we combined a thermoplasmonic stimulation platform based on gold nanorods (GNRs) and near-infrared illuminations (808 nm, spot size: 2 mm or 200μm in diameter) with a proportional-integral (PI) controller. The closed-loop feedback control system was implemented to track predetermined target spike rates of hippocampal neuronal networks cultured on GNR-coated microelectrode arrays.Main results. The closed-loop system for neural spike rate control was successfully implemented using a PI controller and the thermoplasmonic neural suppression platform. Compared to the open-loop control, the target-channel spike rates were precisely modulated to remain constant or change in a sinusoidal form in the range below baseline spike rates. The spike rate response behaviors were affected by the choice of the controller gain. We also demonstrated that the functional connectivity of a synchronized bursting network could be altered by controlling the spike rate of one of the participating channels.Significance.The thermoplasmonic feedback controller proved that it can precisely modulate neural spike rate of neural activityin vitro. This technology can be used for studying neuronal network dynamics and might provide insights in developing new neuromodulation techniques in clinical applications.
Edge-localized-mode simulation in CFETR steady-state scenario
Authors: Tang T.F. , Xu X.Q. , Li G.Q. , Chen J.L. , Chan V.S. , Xia T.Y. , Gao X. , Wang D.Z. , Li J.G.
Published: October 2021

The EPED1 model and self-consistent core-pedestal coupling in integrated modeling are used to design the pedestal structure of the China Fusion Engineering Testing Reactor (CFETR) steady-state scenario. The key parameters, such as β
p and q
95, are based on the grassy edge-localized-mode (ELM) experimental database. In this work, we use the BOUT++ six-field two-fluid code to simulate the onset of the ELM in the CFETR steady-state scenario. The ELM size is around 0.2% in nonlinear simulations, which is in the experimental range of the grassy ELM discharges, 0.1%–1% observed in multiple tokamak devices. Linear and nonlinear simulations show that the dominant high-n ballooning modes peak around n = 40. Compared to type-I ELM crashing dynamics, grassy ELM crashing has a smaller initial crash and is then followed by three phases of turbulence spreading, which are dominated by multi-modes, a high-n mode of n = 45 and low-n mode of n = 5, respectively. In contras to type-I ELM, the perturbation of the high-n mode has a narrow width around ψ = 0.95, and magnetic island formation and reconnection occur only beyond ψ = 0.95, leading to a small initial crash. Mode–mode interaction in the multi-mode coexistence stage stops the growth of individual modes and reduces the transport of particles and heat, and these are the two reasons why the ELM size is small. In–out asymmetry of transient heat flux with a ratio of E
out/E
in = 3.5 is found during grassy ELM crash. The rise and delay times of the heat flux match the calculation from the free-streaming model. To evaluate the erosion of the divertor target, the energy fluence at the outer divertor target is calculated, which is 0.029 MJ m−2, 5.5 times smaller than the tungsten melting limit 0.16 MJ m−2. The calculated energy fluency still follows the experimental scaling law from type-I ELM experiments. The fluctuation eddies in the toroidal direction show a filament structure at the outer mid-plane. Parallel heat flux patterns with a toroidal mode number n = 10 are found at the outer divertor with an amplitude of 680 MW m−2.
Effects of boron doping on the fabrication of dense 6H-SiC ceramics by high-temperature physical vapor transport
Authors: Liu B B , Huang J , Yang J F
Published: October 2021

In this paper, boron-doped dense 6H-SiC ceramics was fabricated by the high-temperature physical vapor transport (HTPVT) method. The effect of B doping on the crystal structure stability of 6H-SiC was investigated based on density functional theory (DFT). The results show that B doping can be realized even under thermodynamical equilibrium conditions. Nevertheless, it is found that the B doping effects on the (0001) of Si-plane and (000-1) of C-plane are significantly different. The doping experiments demonstrated that B can observably change the crystal growth morphology, leading to the formation of elongated 6H-SiC crystals.
Assessment of stress distribution in premium connections with ultrasonic phased array and metal magnetic memory
Authors: Han T , Fan J C
Published: October 2021

The strength and sealing performance of premium connections in high temperature-high pressure (HTHP) gas well is one of the key factors for the integrity of wellbore, in which, the distribution of contact stress is the guarantee of metal-to-metal seals, while the stress distribution will affect the strength on the threaded connection. This paper explained the ultrasonic phased array (UPA) detection for contact stress of sealing surface and metal magnetic memory (MMM) detection for thread stress. The magnetic-acoustic detection test of the full-scale joints was carried out during make-up, with signals characterized the stress changes in the premium connections under the torque, the detection was also carried out during axial tension, with the contact stress of sealing surfaces quantitatively characterized by the reflection coefficient of sealing surfaces and the peak echo ratio between sealing surfaces and the inner wall of pipe. The variation of tangential component of magnetic field intensity has the same trend with that of threaded connection stress, which is linearly related to the change of contact stress in metal-to-metal seals. These findings show that the combination of UPA and MMM provides a reliable detection method for performance assessment on premium connections, both in quality control and in its field inspection.
Damage constitutive model of pure copper at different annealing temperatures
Authors: Li L , Zhu X J , Zhang L , Tian F Z
Published: October 2021

Aiming at the problem of damage evolution of pure copper during the plastic deformation, the normalized shape factor is introduced based on the RO model (Ramberg-Osgood model). The mesoscopic damage constitutive model of pure copper at different annealing temperatures is established and the tensile deformation of industrial pure copper at different annealing temperatures is analyzed. The results show that the error between the calculated value and the experimental value of the damage constitutive model, based on normalized shape factor, at different annealing temperatures, is less than 10%. The model can effectively reveal the tensile damage evolution behavior of industrial pure copper and accurately predict the plastic tensile flow stress of industrial pure copper at different annealing temperatures. The hardening coefficient and hardening exponent in the model are closely related to the annealing temperature of the material. The annealing temperature has little effect on the hardening exponent and has a significant effect on the hardening coefficient and the hardening coefficient decreases with the increase in annealing temperature.
Analysis on accumulated deformation and stress of the steel roof of Beijing Opera House during construction
Authors: Wu L L , Gao G , Ye B R , Zhang H D , Lu Q
Published: October 2021

This paper aims to study the stress and deformation of large steel structure buildings in the actual construction process. Midas Gen finite element software is used to simulate and analyze the whole construction process of the curved reticulated shell roof, the peripheral steel columns and the permanent support. The stress and deformation results of the structure in the final construction state are compared with those in the design state under one-time loading. The results show that, in the final construction state, the maximum tensile stress and the maximum compressive stress are 1.9 times and 2.0 times of that in the design state under one-time loading respectively, which is very significant. When the design model is loaded with weight at one time, the maximum tensile stress and the maximum compressive stress of the structure both appear near the opening of the steel roof, while in the final construction state, the maximum tensile stress of the structure appears near the boundary frame beam, and the maximum compressive stress appears on the main ridge beam. The maximum vertical displacement of the structure in the final construction state is 2.0 times of that when the design model is loaded at one time. The maximum vertical displacement of the design state appears near the opening of the steel roof, while the maximum vertical displacement of the structure in the final construction state appears on the main ridge beam. In view of the above, the effective guidance for the construction of steel roof structure is provided in this paper to ensure the safety of the structure.
Detection techniques for monitoring dioxin-like compounds: latest techniques and the comparison
Authors: Du X Y , Liu X Y , Shang Z Y , Han W S , Zhang H
Published: October 2021

In order to clarify the necessity and urgency of dioxin detection, the characteristics and emission sources were firstly studied in this paper. The current dioxin detection techniques were then summarized, including chemical detection technique represented by HRGC/MS, biological detection technique covering immunology and biotechnology, and laser mass spectrometry technique using fusion ionization technology and time-of-flight mass spectrometry. Then the advantages and disadvantages, representative technologies, development directions and application prospects of various detection methods were analyzed. Eventually, the future development direction of dioxin detection technology was prospected.
Study on the assessment and reduction technology of carbon dioxide from cementing material manufacturing sector
Authors: Liu Y J , Fang J R , Kang Y W , Wang L , An X P
Published: October 2021

For the purposes of simplifying the calculation task, adjusting production processes in time and solving the inconsistent requirements for carbon emissions, this paper investigates the calculation methods of carbon dioxide emissions from cement production, for example IPCC, WBCSD-CSI, MEE-CBMA, CNIS and BNU. Then a simplification and intuitive method is proposed. Based on the intuitive method, CO2 emission of 21 cement plants in China are calculated and analyzed, of which the error between the calculation results and those obtained by HJ 2519-2012 is less than 0.5%. About the carbon reduction technology in cement industry, there is limited reduction space that rely on energy efficiency improvements and clinker substitution. The technology of alternative fuels still needs to be further expanded. China has operated the first demonstration production line of CCUS technology at the Anhui Baimashan Conch cement plant with a capacity of 20,000 tons/year of industrial-grade liquid CO2 products and 30,000 tons/year of food-grade liquid CO2 products. Alternative raw material technology may be one developing direction to cut carbon emission; only 6.18% of steel slag was added to the raw meal at a 2500t/d production line, CO2 emission from process emissions were reduced by nearly 10%.
TRISO Fuel Performance Modelling with BISON
Authors: Collin B , Jiang W , Gamble K , Gardner R , Hales J , Haugh B , Novascone S , Roche J , Spencer B , Toptan A
Published: October 2021

Modeling of tristructural isotropic (TRISO)-coated particle fuel is being refined in the fuel performance code BISON. New developments include the implementation of an updated set of material properties, TRISO failure mechanisms, fission product diffusion parameters, and the design of a Monte Carlo scheme that allows BISON to calculate the probability of fuel failure within a population of TRISO particles and the subsequent fractional release of key fission products.
Capability of Indonesian Hot cell Towards Pebble Bed Post Irradiation Examination
Authors: Setiawan J , Ismarwanti S , Paid A , Rahmatullah H F , Sigit R , Ajiriyanto M K
Published: October 2021

Post irradiation examination is one of the requirements to obtain licensing of nuclear fuel, and the purpose of this activity is to represent the performance of nuclear fuel itself. Currently, Indonesia is developing the 10 MWth high-temperature reactor type with its fuel in the form of pebble bed. Indonesia has a hot cell installation that has a function to do post-irradiated examinations. This hot cell mainly used for plate and rod type fuel. This paper wants to show this installation capability to perform the post-irradiation examinations based on its documents and current status. We also show the future possibility of performing pebble bed post-irradiation examinations. The hot cell installation in Indonesia, mainly divided into two areas. First areas are to perform the examinations in the intact form of fuel and second areas are to perform in the small specimen of fuel. For the future pebble bed examinations, Indonesian hot cell structure is possible to perform these examinations. These examinations are possible with limiting amount and stay time of fuel inside the hot cell. The current status gap with requirements for pebble bed tests such as handling tool, deconsolidation apparatus, simulation accident test apparatus also is described.
The Effect of Catalysts Addition to Silicone Rubber as Pressure Transmitting Medium in the Pebble Fuel Production Process
Authors: Sutarya D , Pamungkas I R , Sukma H , A Sartono DS
Published: October 2021

Pebble Fuel is a spherical fuel for high temperature gas-cooled reactors (HTGR). This fuel must have a homogeneous density distribution. Hyperelastic material is used as a pressure transmitting medium (PTM) material in making Pebble fuel using the cold quasi-isostatic pressing method. PTM material properties and characteristics were predicted using the finite element analysis method. The problem is the type of material used and its suitable composition to make a pressure-transmitting medium that has the properties and characteristics of the material as predicted. This research discusses the manufacture of tensile specimens for pressure-emitting media using RTV-586 silicone rubber. The composition comprises three different variants with two major ingredients, namely RTV-586 silicone rubber and catalyst. The test results are then analyzed using the finite element method to determine the material composition that is appropriate or close to the predicted properties and characteristics of the PTM material. This initial study used the Mooney-Rivlin hyperelastic model. The Mooney-Rivlin model shows good similarity to the test result data. In future studies, it will make comparisons with other hyperelastic models to get a suitable PTM material constant.
Evaluation of PBMR-400 Core Design Steady State Condition with Serpent and AGREE
Authors: Ardiansyah H , Seker V , Downar T , Skutnik S , Wieselquist W
Published: October 2021

The significant recent advances in computer speed and memory have made possible an increasing fidelity and accuracy in reactor core simulation with minimal increase in the computational burden. This has been important for modeling some of the smaller advanced reactor designs for which simplified approximations such as few groups homogenized diffusion theory are not as accurate as they were for large light water reactor cores. For narrow cylindrical cores with large surface to volume ratios such the Ped Bed Modular Reactor (PBMR), neutron leakage from the core can be significant, particularly with the harder neutron spectrum and longer mean free path than a light water reactor. In this paper the core from the OECD PBMR-400 benchmark was analyzed using multigroup Monte Carlo cross sections in the HTR reactor core simulation code AGREE. Homogenized cross sections were generated for each of the discrete regions of the AGREE model using a full core SERPENT Monte Carlo model. The cross sections were generated for a variety of group structures in AGREE to assess the importance of finer group discretization on the accuracy of the core eigenvalue and flux predictions compared to the SERPENT full core Monte Carlo solution. A significant increase in the accuracy was observed by increasing the number of energy groups, with as much as a 530 pcm improvement in the eigenvalue calculation when increasing the number of energy groups from 2 to 14. Significant improvements were also observed in the AGREE neutron flux distributions compared to the SERPENT full core calculation.
Developing a Design Optimization Methodology for the Thermal-Hydraulic Evaluation for a High Temperature Reactor During a DLOCA
Authors: Atkinson Seddon , Gray Ander , Patelli Edoardo
Published: October 2021

Methods of implementing uncertainty within nuclear reactor modelling have traditionally been achieved via worst case scenario uncertainty quantification. This article investigates how this practice can be expanded to provide data on the driving factors behind the temperatures experienced during accident conditions via a global sensitivity analysis. The second part of the article investigates how a stochastic optimization technique can be included within the design process to provide the most cost-effective core geometry which meets the temperature constraints of the fuel and the reactor pressure vessel. The third study investigates the impact of how uncertainty reduction can be used in combination with the stochastic optimization technique to provide further design optimization.
Design of Fault Diagnosis Algorithm for Electromechanical System Based on Artificial Intelligence
Authors: Zhao Fuyou , Huo Mingying , Qi Naiming , Li Lianfeng , Cui Weiwei
Published: October 2021

A relatively perfect system for the fault diagnosis of mechanical and electrical products has been formed through decades of development. Nevertheless, the traditional fault diagnosis methods fail to cope with the gradual huge mechanical and electrical system. As a result, the advantages of fault diagnosis mode driven by data are increasingly prominent. Meanwhile, the effect of fault diagnosis has exceeded the traditional fault diagnosis methods in many fields. Through the use of the deep learning technology based on artificial intelligence, it carries out mapping and fitting. By fully taking advantages of neural network, it can effectively obtain the accurate classification of fault data. A fault diagnosis method based on the fault data of mechanical and electrical system is designed in this thesis. When it comes to the basic process, it is to take data sets for different mechanical and electrical products. Through the use of feature engineering method, it extracts the fault features of data. Through the use of deep learning technology, it carries out the intelligent diagnosis. According to the experimental results, it indicates that the fault diagnosis method based on deep learning technology can distinguish a variety of fault modes in mechanical and electrical system in an effective way. What’s more, good classification results in fault recognition have been achieved by a variety of deep convolutional neural network structures, so the feasibility of the method is further verified.
Passive design of buildings: A review of configuration features for natural ventilation and daylighting
Authors: Loo S-H , Lim P I , Lim B H
Published: October 2021

Passive design involves the utilization of natural forces such as natural ventilation and daylighting without mechanical input of energy, and is a subset of environmentally sustainable design (ESD), which offers solutions for more environmentally friendly buildings. This review is based on the premise that ESD interventions have an inherent cost on building projects. The aim is to review existing research on applications of various building configurations for facilitating the economical application of passive design, in terms of natural ventilation and daylighting. A systematic review of existing research during the previous decade (2010 – 2020) was conducted. In our findings, we compare and categorise concepts within building configuration in terms of their applicability to natural ventilation and daylighting. Our review identified seven categories of building configuration ie. building geometry, interior, context, envelope, fenestration, building plan and voids, with their associated parameters. It was discovered that building fenestration was the most frequently researched followed by building voids. The identified parameters point to the variety, diversity and trends of research in the field. The knowledge can be used in familiarising, assessing and evaluating various aspects of passive design of building configuration towards energy saving and ESD.
Stochastic type-2 fuzzy modelling on GHG emission prediction for gas-fired power plant
Authors: Zakaria Sazalina , R. Ahmad Radin Diana , Abbas Ahmad Rosly , Mohideen Batcha Mohd Faizal , Zanil Mohd Fauzi
Published: October 2021

This paper demonstrates the implementation of type-2 fuzzy logic model in prediction of greenhouse gas emission for gas fuelled power plant. The data collection and analysis on the GHG emission had been conducted with emphasis on the industrial scale with many uncertainty factors. The developed model will be used as a prediction tools to evaluate potential GHG emission for future study and mitigation planning. In this work, 100 sample sizes had been used as training dataset in the model framework which serve as the input information while 14 sample sizes are used for model validation to achieve model generalization. A novel Karnik-Mendel (KM) algorithm had been proposed with the Genetic Algorithm (GA) model optimization to achieve high performance and accuracy for the respective predictive model. In conclusion, the result showed that the model able to give an outstanding accuracy. On the validation analysis, the results showed developed model able to give satisfactory prediction with R2 of 0.978 and 0.84968 for training and validation, respectively.
Numerical studies of fluid flow and heat transfer in microchannel heat sink with trapezoidal cavities, ribs and secondary channel
Authors: Razali S A , Sidik N A C , Yusof S N A
Published: October 2021

In order to improve reliability and prevent premature failure, heat produced by electronic devices must be transfer efficiently. The microchannel heat sink appears to be the most reliable cooling technology to improve heat transfer performance. A new Microchannel Heat Sink (MCHS) design has been proposed with trapezoidal cavities, ribs and secondary channels. Fluid flow and heat transfer characteristics for Reynold numbers from 100 to 500 are numerically studied and analysed. Four microchannel heat sinks with various related geometry have been considered in this study, for instance, microchannel with rectangular ribs (TRAC-RR) and microchannel with trapezoidal cavities (TRAC). The finite volume method (FVM) is used to solve the governing equations, and the computations are performed using the SIMPLE algorithm. The present design’s overall performance is evaluated using the friction factor, the Nusselt number, and performance evaluation criteria (PEC). The results show that the TRAC-RR-SC MCHS is the best design for the proposed design compared to the other four geometries, with a maximum PEC of 1.78. Additionally, the secondary flow field analyses visually show the hydraulic and thermal performance enhancements due to interruption, flow mixing and redevelopment of the thermal boundary layer.
Nitrogen Gas Adsorption Filter (NgAF) to enhance producer gas quality
Authors: Mohammud Mohd Mahadzir , Mohd Fohimi Nor Azirah , Hamid Pahmi Muhammad Arif Ab , Hairun Anuar Ariffatul Amirah
Published: October 2021

Biomass gasification is a thermochemical conversion process of solid biomass into a gaseous fuel called producer gas that can be used to generate power and electricity. The producer gas consists of around 47% of Nitrogen (N2), 24% Carbon Monoxide (CO), 16% Carbon Dioxide (CO2), 12% Hydrogen (H2), and 1% Methane (CH4). However, Nitrogen (N2) content in the producer gas reduces its heating values as N2 acts as a diluent because of the low calorific value (LCV) of gas. This study aims to design a Nitrogen gas filter for capturing nitrogen gas from producer gas to increase the heating value of producer gas as fuel in combustion. The method to increase the heating value of producer gas will increase the number of combustible gases or reduce the composition of non-combustible gases in producer gas. The use of material name zeolite with its microporous structures able to adsorb nitrogen molecules and act as catalysts to chemical reactions. Zeolites 5A have a small pore highly efficient to adsorb nitrogen gas because pore diameter is relatively similar to the size of nitrogen molecules. The quality of the producer gas depends on the design and operating parameters of the zeolite catalyst. Nitrogen Gas Adsorption Filter is a new method that has to be designed to improve the previous producer gas quality. Nitrogen Gas Adsorption Filter consists of a cylindrical shape body packed with crushed zeolites 5A. When this method of adsorption process is applied, the heating value of the producer gas is increased by observing the quantity of blue flame colour produced by NgAF.
Structural, thermal and optical studies of Eu3+ ion doped Ge22As20Se58 glass
Authors: Singh Amarendra Kumar , Mehta Neeraj , Mishra Hirdeysh , Mishra S K
Published: October 2021

The effect of Eu3+ doping on improving the amorphous nature of commercial chalcogenide glass/ChG (Ge22As20Se58), which is typically used as a molded lens for mid-infrared imaging, has been investigated. The observed absence of bright spots in Transmission Electron Microscope-Selected area (electron) diffraction (TEM-SAED) pattern confirmed the doping-induced amorphous nature of Eu-Ge22As20Se58 glass. The thermal studies over glass transition temperature (Tg) using DSC technique also revealed that Eu doping has increased the amorphous nature along with the thermal stability of Ge22As20Se58 glass. The optical analysis using UV–vis absorption spectroscopy showed that the activity of Eu-doped ChG has been extended across the UV-visible region. Tauc plot derived band gap energy of Eu-doped and undoped ChG is found to be 2.2 and 2.6 eV, respectively.
Hot filament chemical vapor deposition temperature field optimization for diamond films deposited on silicon nitride substrates
Authors: Wu Yuhou , Zhang Huisen , Yan Guangyu , Liu Lusheng , Cristea Daniel , Wang He , Yang Yumiao , Shen Jianhui
Published: October 2021

The influence of some key parameters of hot filament chemical vapor deposition (HFCVD) on the temperature distribution during the deposition of diamond coatings on silicon nitride (Si3N4) substrates was assessed with the help of the finite element method. Solid heat transfer, fluid heat transfer and surface radiation heat transfer mechanisms were used to calculate the substrate temperature in the steady state during the deposition process. The accuracy of the model was verified by comparing the simulation model with experimental measurements. The comparison shows that the deviation between the model and the actual substrate temperature measurements is within 3%. Furthermore, a Taguchi orthogonal experiment was designed (3 factors, 3 levels, L9). By changing the number of hot filaments, the distance between the filaments and the substrate, and the separation between two adjacent hot filaments, the influence trend of these parameters on the substrate temperature was assessed, leading to an optimal hot filament arrangement. A deposition experiment was carried out using the optimized parameters, and the results showed that the substrate surface temperature obtained by numerical simulation is highly consistent with the temperature measured by the infrared thermometer. The optimized deposition parameters contributed to a more suitable temperature range and more uniform temperature distribution on the Si3N4 ceramic substrate. The deposited diamond film exhibited uniform crystal quality and grain morphology, thus verifying the validity of the simulation results.
Effect of laser power and scanning speed on the characteristics of laser metal deposition of Ti6Al4V + W composite powder on Ti6Al4V substrate
Authors: Ndou Ndivhuwo , Mubiayi Mukuna Patrick
Published: October 2021

The usage of different powders to enhance the surface properties of base materials has an impact on the cost. Laser Metal Deposition (LMD) of Ti6Al4V + W composite was used and the effect of laser power and scanning speed was investigated. The microstructure, microhardness, and x-ray diffraction analyses, and wear tests were conducted. The microstructure of the samples fabricated using higher laser power (1400W) displayed larger grains when compared to the ones fabricated using lower laser power (800 W). The Full Width at Half Maximum (FWHM) values showed some changes with the variation of scanning speeds. Furthermore, the x-ray diffraction patterns did not show the formation of new phases. A similar trend on the microhardness profiles for all the fabricated samples was observed. Higher microhardness values were observed in the top part of the deposited material. The microhardness profile showed similar trends for all the analysed samples. Higher microhardness values were measured at the top of deposition and decreased progressively. On the other hand, the scanning speed did not affect the wear volume, though the highest wear volume of 0.144 mm was observed for the sample fabricated using 800 W laser power and 0.7 m min−1. This shows that process parameters such as laser power and scanning have an impact on the resulting properties of deposited composite material.
A review of printable, flexible and tissue equivalent materials for ionizing radiation detection
Authors: Posar Jessie A , Petasecca Marco , Griffith Matthew J
Published: October 2021

Advances in flexible and printable electronics have paved the way for large-area, and low-cost wearable electronics that will revolutionize the way we detect and monitor ionizing radiation. The improvements to early detection and widespread use of treatment procedures of tumors and other illnesses using ionizing radiation have led to the rapid increase in the yearly dose exposure to the public. Therefore, safety organizations must introduce stricter quality assurance measures to ensure the safe delivery of the total dose to the patient—only achievable using live monitoring systems, named in-vivo dosimetry. Such systems would also benefit the safety of professional personnel employed in areas that encounter higher exposures of ionizing radiation including nuclear plants, space exploration, flight staff, and research beamline facilities. However, the current real-time detectors employ expensive and rigid high-Z materials including silicon, germanium, and cadmium telluride, that suffer substantial limitations in monitoring the dose deposited in biological tissue and conforming to the complex contours of the human body over large areas. We provide insights into the innovative materials capable of solution-based device fabrication onto flexible substrates with foreseeable avenues towards low-cost large-area printing techniques. This discussion will also review and identify the advantages and existing capabilities of tissue-equivalent materials in the detection of ionizing radiation as the ideal materials for in-vivo dosimetry. Finally, the radiation tolerance of organic materials is outlined to demonstrate that extensive investigations are still required before their utilization as radiation detectors.
Markov modelling of treatment response in a 30-year cohort study of newly diagnosed epilepsy
Authors: Simpson Hugh D , Foster Emma , Ademi Zanfina , Lawn Nicholas , Brodie Martin J , Chen Zhibin , Kwan Patrick
Published: October 2021

People with epilepsy have variable and dynamic trajectories in response to antiseizure medications. Accurately modelling long-term treatment response will aid prognostication at the individual level and health resource planning at the societal level. Unfortunately, a robust model is lacking. We aimed to develop a Markov model to predict the probability of future seizure-freedom based on current seizure state and number of antiseizure medication regimens trialled.

We included 1795 people with newly diagnosed epilepsy who attended a specialist clinic in Glasgow, Scotland, between July 1982 and October 2012. They were followed up until October 2014 or death. We developed a simple Markov model, based on current seizure state only, and a more detailed model, based on both current seizure state and number of antiseizure medication regimens trialled. Sensitivity analyses were performed for the regimen-based states model to examine the effect of regimen changes due to adverse effects. The model was externally validated in a separate cohort of 455 newly diagnosis epilepsy patients seen in Perth, Australia, between May 1999 and May 2016.

Our models suggested that once seizure-freedom was achieved, it was likely to persist, regardless of the number of antiseizure medications trialled to reach that point. The likelihood of achieving long-term seizure-freedom was highest with the first antiseizure medication regimen, at approximately 50%. The chance of achieving seizure-freedom fell with subsequent regimens. Fluctuations between seizure-free and not seizure-free states were highest earlier on but decreased with chronicity of epilepsy. Seizure-freedom/recurrence risk tables were constructed with these probability data, similar to cardiovascular risk tables. Sensitivity analyses showed that the general trends and conclusions from the base model were maintained despite perturbing the model and input data with regimen changes due to adverse effects. Quantitative comparison with the external validation cohort showed excellent consistency at Year 1, good at Year 3 and moderate at Year 5.

Quantitative models, as used in this study, can provide pertinent clinical insights that are not apparent from simple statistical analysis alone. Attaining seizure freedom at any time in a patient’s epilepsy journey will confer durable benefit. Seizure-freedom risk tables may be used to individualize the prediction of future seizure control trajectory.
Studies on pathways to carbon neutrality for indirect coal liquefaction in China
Authors: Li Chufu , Li Yonglong , Xu Ming , Gong Yan , Gong Siqi , Wang Peng , Li Pingping , Dong Binqi , Men Zhuowu
Published: October 2021

The production capacity of indirect coal liquefaction (ICL) in use in China has reached a level of 8 million t/a, which corresponds to a carbon footprint of >60 million t/a. ICL is facing mountainous pressure to reduce its carbon emissions when its development is planned with carbon neutrality as a background objective. This paper studies the pathways that can lead to carbon neutrality for ICL in China, constructing four carbon-neutral pathways for ICL systems with the introduction of green hydrogen, biomass as feedstock and with CCS (carbon capture and storage), which can reduce significant carbon emissions from coal-gasification and water–gas shift processes. The carbon-neutral biomass is used to replace some coal as co-feed to gasification and combustion, leading to reduced carbon emissions as well. Calculations and economic analyses are performed on different carbon-reduction pathways using a carbon-neutral ICL system on a 1 million t/a scale as an example. The results are that the pathway of direct coal substitution with biomass is the lowest carbon-reduction route at RMB 31~125/t CO2, substitution with green hydrogen costs the highest at RMB 84~422/t CO2 and CCS costs are in the middle at RMB 96~148/t CO2. Each pathway has its pros and cons, and a combination of the three may be used for the best outcome. Furthermore, a comprehensive study and systematic summation of the critical technological processes and their underlying challenges for carbon-neutral ICL together with direction for a technological breakthrough are presented. These ICL carbon-reduction pathways presented in this paper are capable of realizing an integrated development between fossil and renewable energy sources, helping the carbon-intense coal-chemical industries to achieve their goals of carbon peak and carbon neutrality.
The COVID-19 disaster and mental health—assessing, responding and recovering
Authors: Lindert Jutta , Jakubauskiene Marija , Bilsen Johan
Published: October 2021

The coronavirus disease 19 (COVID-19) pandemic is a disaster that has impacted lives globally. The purpose of this paper is to understand the linkage between COVID-19 and its impact on mental health. To reach this aim, we reviewed the literature on COVID-19 and mental conditions. Based on the literature, we identified COVID-19 as an unexpected, large-scale event that disrupted communities and caused death, destruction and trauma which upended normal existence. For mental conditions, effects of the pandemic are likely to manifest in different ways: development of symptoms in previously healthy individuals, new episodes in those with predisposition to mental disorders and development of symptoms that do not meet diagnostic criteria. The level of mental health problems varies depending on the stage of the pandemic, country, population groups and types of conditions. This also applies to the level of suicide, although suicides do not seem to have increased during the pandemic. Yet, we identified a net of factors contributing to mental conditions, in general. These factors include demographic factors (e.g. female gender, younger and older age), social factors (e.g. economically disadvantaged), mental factors (e.g. pre-existing mental conditions) and relationship factors (e.g. stressful relationship, lack of relationships). Additionally, we identified COVID-19-specific factors such as threat to own life and threat to life of loved ones, containment measures and interruption of services and social life. We further explored potentially additional suicide-related risk factors. Regardless of differences, health care and psychosocial systems were in many countries not prepared to respond to a viral disaster. Viral disaster requires that responses not only include direct care but also responses to populations that may need support due to known determinants of mental health.