bluuebunny/crossref_metadata_2025 huggingface dataset:
Impulse mitigation in nonlinear composite-based woodpile phononic crystals
Authors: Jang Yeongtae , Lee Geon , Kim Eunho , Rho Junsuk
Published: November 2022

In this work, we study the mitigation of stress waves in composite-based woodpile phononic crystals composed of heterogeneous cylindrical rods, whose bending mode exhibits local resonant behavior that strongly interferes with external perturbation. Impulse excitation in this system is transformed into several modulated wave patterns depending on resonant frequencies and their mechanical properties. Thus, these mechanisms have been a candidate for novel methods of shock mitigation without relying on material dissipation. Here, we suggest the mechanical system consisting of the unit cell's composite configuration as an approach for more efficient shock attenuation. To efficiently analyze the nonlinear wave dynamics of the proposed systems, we present an extended discrete element model (DEM) resulting from a combination of an analytic beam theory with the discretization model. We numerically and experimentally demonstrate extreme dispersive waves for shock mitigation by adjusting the weighted composition ratio of the heterogeneous cylinder. Using the verified DEM, we also investigate the strong attenuation performance of incident impulse in disorder-induced systems with different nonlinear strengths. We, thus, expect that these composite-based mechanical systems could be used to design tunable modulation energy transport and efficient impact protector devices.
High volume UV LED performance testing
Authors: Letson Benjamin C. , Barke Simon , Kenyon Samantha Parry , Olatunde Taiwo , Mueller Guido , Wass Peter , Ren Fan , Pearton Stephen J. , Conklin John W.
Published: November 2022

There is increasing interest in deep UV Light-Emitting Diodes (LEDs) for applications in water purification, virus inactivation, sterilization, bioagent detection, and UV curing, as well as charge management control in the Laser Interferometer Space Antenna (LISA), which will be the first gravitational wave detector in space. To fully understand the current state of commercial UV LEDs and assess their performance for use on LISA, large numbers of UV LEDs need to be tested across a range of temperatures while operating in air or in a vacuum. We describe a new hardware system designed to accommodate a high volume of UV LED performance tests and present the performance testing results from over 200 UV LEDs with wavelengths in the 250 nm range.
Oxide magnonics: Spin waves in functional magnetic oxides
Authors: Zhang Yuelin , Chen Jilei , Zhang Jinxing , Yu Haiming
Published: November 2022

Spin waves or their quanta magnons are collective excitations in magnetically ordered materials. Magnonics have recently attracted tremendous interest for building next-generation nanoscale devices and circuits with low-power consumption. Oxide materials provide an excellent platform for achieving highly efficient spin-wave excitation and transmission for magnonic applications with versatile functionalities. In this article, we review some recent advances for oxide-based magnonics, including both magnetic oxides for hosting spin waves and non-magnetic oxides for manipulating spin waves. First, we introduce recent development on coherent propagation and incoherent transport of magnons in thin-film iron garnets, low-damping ferrimagnetic oxides widely used in magnonics. Then, we discuss spin-wave chirality due to the inversion symmetry broken in magnetic oxides. Magnonics in antiferromagnetic oxides is also presented, where the spin-wave resonance frequency enters THz regime. Nanoscale spin textures, such as magnetic skyrmions, can be stabilized in magnetic oxides, and provide additional versatilities by coupling their dynamics with spin waves. Last but not the least, we highlight the electrical control of spin waves based on multiferroic oxides toward applications for hybrid magnonics.
Thermodynamic modeling for numerical simulations based on the generalized cubic equation of state
Authors: Trummler T. , Glatzle M. , Doehring A. , Urban N. , Klein M.
Published: November 2022

We further elaborate on the generalized formulation for cubic equation of state proposed by Cismondi and Mollerup [Fluid Phase Equilib. 232, 74–89 (2005)]. With this formulation, all well-known cubic equations of state can be described with a certain pair of values, which allow for a generic implementation of different equations of state. Based on this generalized formulation, we derive a complete thermodynamic model for computational fluid dynamics simulations by providing the resulting correlations for all required thermodynamic properties. For the transport properties, we employ the Chung correlations. Our generic implementation includes the often used equations of state Soave–Redlich–Kwong and Peng–Robinson and the Redlich–Kwong–Peng–Robinson equation of state. The first two assume a universal critical compressibility factor and are, therefore, only suitable for fluids with a matching critical compressibility. The Redlich–Kwong–Peng–Robinson overcomes this limitation by considering the equation of state parameter as a function of the critical compressibility. We compare the resulting thermodynamic modeling for the three equations of state for selected fluids with each other and CoolProp reference data. Additionally, we provide a Python tool called real gas thermodynamic python library (realtpl). This tool can be used to evaluate and compare the results for a wide range of different fluids. We also provide an implementation of the generalized form in OpenFOAM.
Wake flow characteristics and unsteady performance of a pump-jet propulsor under hull condition
Authors: Shi Shuaikang , Tang Wanghao , Huang Xiuchang
Published: November 2022

The propulsor is one of the main noise sources of an underwater vehicle. The pump-jet operating under hull condition is in a typical non-uniform strong anisotropic turbulent flow field. In this paper, the wake flow characteristics and unsteady performance of a pump-jet propulsor under hull condition are numerically investigated. Reynolds-averaged Navier–Stokes (RANS) method and large eddy simulation (LES) method are used to evaluate and compare the ability of solving vortex structure, pressure distribution and unsteady force. LES method can capture the interaction between different vortex systems, and the vortex shedding process of the stator wake and appendage wake. These lead to that the frequency spectra of fluctuation pressure have peaks in the low-frequency range for LES method. For unsteady force spectrum, the frequency of maximum amplitude of a single blade is mainly affected by relative intensities of the stator wake and appendage wake. “Humps” appear near the blade passing frequency and its multiples for unsteady force spectrum of the rotor for LES method. The blade passing frequency in the rotor force spectrum is generated by the phase cancelation between different blades. The completeness of rotor blade phase cancelation is mainly affected by the intensity of the non-stationarity in the flow field. Overall, it is sufficient to clarify the hydrodynamic performance and the characteristics of fluctuation pressure distribution of the pump-jet with RANS method. The LES method is necessary to obtain reasonable transient characteristics of the unsteady force and vortex system interaction for the pump-jet under hull condition.
High-speed imaging of degassing kinetics of CO2–water mixtures
Authors: Boeije Chris , Zitha Pacelli , Pluymakers Anne
Published: November 2022

The exsolution of gas molecules from gas–liquid mixtures plays a significant role in a wide range of applications from industrial processes such as metal casting to subsurface flow of oil or geothermal waters. This study aims to improve the understanding of the conditions under which free gas bubbles start forming in CO2–water mixtures. The bubble point pressure was determined under various different conditions like the temperature and initial pressure of the mixture along with other parameters such as the bubble growth rate. A series of depressurization experiments at high pressure and temperature (up to 100 bar and 100 °C) is performed using a pressure cell that allows for visual monitoring of the degassing process. Bubble formation during the depressurization process is recorded using a high-speed camera paired with a uniform light source along with a pressure transducer and thermocouple. Image analysis allows for the determination of the bubble point pressure and rate of bubble formation. For CO2 in its gaseous state and at moderate temperatures, decent agreement between experimental results and the theoretical bubble point pressure is found, although significant deviations are observed at elevated temperatures. More pronounced differences in bubble point are observed for mixtures starting out at high pressures where CO2 is a supercritical fluid, which lead to lower than expected bubble point pressures.
Temperature dependent nonequilibrium magneto-transport in a correlated polar single molecular transistor with quantum dissipation
Authors: Bhattacharyya Kuntal , Kalla Manasa , Chatterjee Ashok
Published: November 2022

Quantum magneto-transport in a dissipative single molecular transistor is investigated at finite temperature in the presence of electron correlation and electron–phonon interaction within the framework of the Anderson–Holstein–Caldeira–Leggett Hamiltonian. The electron–phonon interaction and dissipation are dealt with by canonical transformations and the Coulomb correlation is treated at the mean-field level. The transport properties such as spectral function, tunneling current, differential conductance, and spin polarization are determined using the Keldysh method.
Mesoscopic simulation of liquid bridge spreading under squeezing of parallel plates
Authors: Wang Jinhe , Li Jiaming , Pan Dingyi
Published: November 2022

The spreading behavior of a droplet under squeezing between parallel plates is seen in the adhesion of microelectronic components and the lubrication of human joints, which is a process involving complex micro-scale flow behaviors, such as three-phase contact line movement. In this study, a many-body dissipative particle dynamics method is employed to account for this process. The method has been first validated by comparing with Cox's theory of contact lines. Two stages have been identified during the process of squeezing: a contact line retraction state and a symmetrical spreading state, which can also be reflected by the change of the system's surface energy. The combined effects of the squeezing velocity and plate's wettability on the appearance of the first stage have been investigated, showing that a large enough squeezing velocity and a hydrophobic enough substrate will lead to no contraction of the contact line. This study provides a valuable tool to explore the possibility of controlling the droplet squeezing behavior and, thus, is helpful for optimizing the adhesion and lubrication process.
Colossal barocaloric effects in adamantane derivatives for thermal management
Authors: Salvatori Alejandro , Negrier Philippe , Aznar Araceli , Barrio María , Tamarit Josep Lluís , Lloveras Pol
Published: November 2022

Plastic crystals are currently attracting interest because their solid-state caloric functionality could be used to tackle climate change in two critical areas: (i) more environmentally friendly cooling and heating driven by pressure and (ii) passive waste heat management. Here, we suggest that plastic crystals could also be used for active pressure-assisted (i.e., barocaloric) waste heat management. In contrast to the barocaloric cooling/heating cycle, for active barocaloric waste heat management, the hysteresis may not be a constraint and transition temperatures above ambient are usually desired. In contrast to passive waste heat management, the application of pressure can be an advantage to actively control the absorption and delivery of heat by the plastic crystal. Here, we have investigated the pressure-induced caloric response at the first-order phase transitions occurring above room temperature of three plastic crystals derived from adamantane: 1-adamantanol, 2-adamantanol, and 2-methyl-2-adamantanol. Colossal barocaloric effects have been found for two of them under small pressure changes of 50 MPa. This behavior occurs thanks to a colossal transition entropy change and a large transition sensitivity to pressure, which can simultaneously take place due to enormous transition volume changes. The balance between configurational and volumic entropy changes at the transition has also been discussed. For 2-adamantanol, in addition to the transition to the plastic phase, the less energetic triclinic-to-monoclinic transition at lower temperatures has also been analyzed. The transition temperatures above ambient make these compounds suitable for waste heat management and, thanks to a small hysteresis, also for industrial cooling and heat pumping.
Uniaxial pulling and nano-scratching of a newly synthesized high entropy alloy
Authors: Fan Pengfei , Katiyar Nirmal Kumar , Zhou Xiaowang , Goel Saurav
Published: November 2022

Multicomponent alloys possessing nanocrystalline structure, often alluded to as Cantor alloys or high entropy alloys (HEAs), continue to attract the great attention of the research community. It has been suggested that about 64 elements in the periodic table can be mixed in various compositions to synthesize as many as ∼108 different types of HEA alloys. Nanomechanics of HEAs combining experimental and atomic simulations are rather scarce in the literature, which was a major motivation behind this work. In this spirit, a novel high-entropy alloy (Ni25Cu18.75Fe25Co25Al6.25) was synthesized using the arc melting method, which followed a joint simulation and experimental effort to investigate dislocation-mediated plastic mechanisms leading to side flow, pileup, and crystal defects formed in the sub-surface of the HEA during and after the scratch process. The major types of crystal defects associated with the plastic deformation of the crystalline face-centered cubic structure of HEA were 2,3,4-hcp layered such as defect coordination structures, coherent ∑3 twin boundary, and ∑11 fault or tilt boundary, in combination with Stair rods, Hirth locks, Frank partials, and Lomer–Cottrell locks. Moreover, 1/6 <112> Shockley, with exceptionally larger dislocation loops, was seen to be the transporter of stacking faults deeper into the substrate than the location of the applied cutting load. The (100) orientation showed the highest value for the kinetic coefficient of friction but the least amount of cutting stress and cutting temperature during HEA deformation, suggesting that this orientation is better than the other orientations for improved contact-mode manufacturing.
Corrigendum to: Effects of mobile phone use on semen parameters: a cross-sectional study of 1634 men in China
Authors: Zhang Shanshan , Mo Fengyi , Chang Yali , Wu Shufang , Ma Qing , Jin Fan , Xing Lanfeng
Published: November 2022

Mobile phones play an irreplaceable role in modern people’s lives. However, the radiofrequency electromagnetic radiation produced by mobile phones has also caused increasing concern. A cross-sectional study was conducted to investigate the effect of radiofrequency electromagnetic radiation produced by mobile phones on semen parameters in 1634 men who underwent semen examination at the Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, China. Analysis of variance and multivariate linear regression were used to explore differences among different groups. A P < 0.05 was considered statistically significant. The results showed significant associations among different groups of daily mobile phone use time and daily duration of phone calls in the percentage of progressively motile spermatozoa (P = 0.004 and P = 0.007), rapid progressively motile spermatozoa (P = 0.012 and P = 0.006) and total motile spermatozoa (P = 0.004 and P = 0.046). After adjustments for the confounding effects of age and body mass index by multiple linear regression, the results showed that the daily duration of mobile phone use had a negative effect on sperm motility. However, there was no statistically significant correlation between daily phone call duration and sperm motility. Therefore, the daily duration of mobile phone use may negatively affect sperm motility and impair male fertility.
Corrigendum to: Local patterns of edaphic mesofauna distribution in the arid Patagonian steppe, Argentina
Authors: Manzo Rosa M. , Manzo Luz M , Rizzuto Susana , Valenzuela M. Fernanda , Martínez Pablo A
Published: November 2022

Mesofauna represents a major component of soil biological community and play a critical role in maintaining soil quality, as well as a range of ecosystem functions. A split–split plot design was performed with the aim of identifying the main predictors (phytogeographical criteria, cover type and environmental variables) of edaphic community structure under the effect of desertification. The study also aimed to examine the spatial and seasonal distribution of mesofauna community according to phytogeographical criteria (shrubland vs grassland) and cover type (bare vs covered soil) in the north-western Patagonian steppe of Argentina. The relationship between edaphic fauna, environmental variables and site location was investigated using redundancy analysis (RDA), while the main predictors of edaphic community were analysed using generalised linear mixed models (GLMMs). A total of 43 taxa of Oribatida were found in 168 samples. GLMM approaches selected cover type due to its higher effect on mesofauna community. In this sense, cover type was more important than phytogeographical criteria and environmental variables as predictor of mesofauna community. These findings contribute to a better understanding of how the distribution of mesofauna community respond in Patagonia steppe.
Conversion of CO
2
into organic acids by engineered autotrophic yeast
Authors: Baumschabl Michael , Ata Özge , Mitic Bernd M. , Lutz Lisa , Gassler Thomas , Troyer Christina , Hann Stephan , Mattanovich Diethard
Published: November 2022

The increase of CO
2
emissions due to human activity is one of the preeminent reasons for the present climate crisis. In addition, considering the increasing demand for renewable resources, the upcycling of CO
2
as a feedstock gains an extensive importance to establish CO
2
-neutral or CO
2
-negative industrial processes independent of agricultural resources. Here we assess whether synthetic autotrophic
Komagataella phaffii
(
Pichia pastoris
) can be used as a platform for value-added chemicals using CO
2
as a feedstock by integrating the heterologous genes for lactic and itaconic acid synthesis.
13
C labeling experiments proved that the resulting strains are able to produce organic acids via the assimilation of CO
2
as a sole carbon source. Further engineering attempts to prevent the lactic acid consumption increased the titers to 600 mg L
−1
, while balancing the expression of key genes and modifying screening conditions led to 2 g L
−1
itaconic acid. Bioreactor cultivations suggest that a fine-tuning on CO
2
uptake and oxygen demand of the cells is essential to reach a higher productivity. We believe that through further metabolic and process engineering, the resulting engineered strain can become a promising host for the production of value-added bulk chemicals by microbial assimilation of CO
2
, to support sustainability of industrial bioprocesses.
The evaluation of cochlear implant users’ acoustic change detection ability
Authors: Saraç Kaya Eylem , Türkyılmaz Meral Didem , Yaralı Mehmet
Published: November 2022

Objectives

This study aimed to evaluate the relationship between behaviourally acquired Acoustic Change Detection Test (ACDT) responses and electrophysiologically obtained Acoustic Change Complex (ACC) responses in participants with Cochlear Implant (CI).

Methods

28 unilateral adult CI users (mean age 41) participated in the study. In behavioural test session, ACDT and speech tests were administered. In electrophysiological test session, sound onset and ACC responses of participants stimulated by/ui/speech structure were recorded and N1–P2 peak-to-peak amplitude and N1 latencies were determined.

Results

No significant correlation was found between individuals’ behavioural and electrophysiological responses but it was observed that individuals dived into two clusters in terms of ACDT responses (p < 0.05). A statistically significant difference was found between the mean ACC amplitudes of the clusters. No statistically significant difference was observed between the mean ACC N1 latency findings of the clusters, suggesting that ACC amplitude may be a better predictor than latency in auditory discrimination.

Conclusion

ACC measurement may be a potential clinical tool to evaluate auditory discrimination performance in individuals with CI, but using the electrophysiological and behavioural tests together may provide a more holistic perspective.
Enhancement of H2S sensing performance of rGO decorated CuO thin films: experimental and DFT studies
Authors: Kumar Sumit , Chaurasiya Rajneesh , Khan Mustaque A , Meng Gang , Chen Jen-Sue , Kumar Mahesh
Published: November 2022

We demonstrate a highly selective and sensitive Cupric oxide (CuO) thin film-based low concentration Hydrogen sulfide (H2S) sensor. The sensitivity was improved around three times by decorating with reduced graphene oxide (rGO) nanosheets. CuO thin films were deposited by Chemical Vapor Deposition followed by inter-digital electrode fabrication by a thermal evaporations system. The crystal structure of CuO was confirmed by x-ray diffraction. The sensing response of pristine CuO was found around 54% at 100 °C to 100 ppm of H2S. In contrast, the sensing response was enhanced to 167% by decorating with rGO of 1.5 mg ml−1 concentration solution. The sensing was improved due to the formation of heterojunctions between the rGO and CuO. The developed sensor was examined under various gas environments and found to be highly selective towards H2S gas. The improvement in sensing response has been attributed to increased hole concentration in CuO in the presence of rGO due to the Fermi level alignment and increased absorption of H2S molecules at the rGO/CuO heterojunction. Further, electronic structure calculations show the physisorption behavior of H2S molecules on the different adsorption sites. Detailed insight into the gas sensing mechanism is discussed based on experimental results and electronic structure calculations.
Low-pass U-Net: a segmentation method to improve strip steel defect detection
Authors: Liu Bo , Yang Bin , Zhao Yelong , Li Jianqiang
Published: November 2022

The detection of strip steel surface defects is critical to ensuring the quality of strip steel products. Many deep learning-based methods have been presented and can achieve outstanding performance. However, most of these methods ignore the frequency information among defect areas, which plays an important role in defect detection. This paper proposes a deep learning method to further improve defect segmentation effects based on existing methods, called low-pass U-Net. Since most defects in strip steel are located in high-frequency areas, we implement a low-pass filter before downsampling in the encoder, which prevents aliasing and separates out high-frequency information. The high-frequency feature is transferred into the decoder to assist segmentation. Following previous studies, we propose an adaptive variance Gaussian low-pass layer to generate different filters according to each spatial location of the feature map, with lower computing resource use. Furthermore, to detect defects at significantly different scales, an improved Hypercolumn module is adopted at the end of the decoder to upsample and fuse the feature maps in different resolutions, where Subpixel replaces the bilinear interpolation to refine the upsampled results. The proposed method is validated on practical datasets and achieves considerable performance improvement (with a best Dice coefficient of 0.903), which demonstrates the effectiveness of low-pass U-Net. The introduction of the adaptive variance Gaussian low-pass filter layer results in a 3% increase in Dice coefficient in a comparative inference time, which achieves a balance in performance, inference time and complexity.
Machine learning-based predictions of gamma passing rates for virtual specific-plan verification based on modulation maps, monitor unit profiles, and composite dose images
Authors: Quintero Paulo , Benoit David , Cheng Yongqiang , Moore Craig , Beavis Andrew
Published: November 2022

Machine learning (ML) methods have been implemented in radiotherapy to aid virtual specific-plan verification protocols, predicting gamma passing rates (GPR) based on calculated modulation complexity metrics because of their direct relation to dose deliverability. Nevertheless, these metrics might not comprehensively represent the modulation complexity, and automatically extracted features from alternative predictors associated with modulation complexity are needed. For this reason, three convolutional neural networks (CNN) based models were trained to predict GPR values (regression and classification), using respectively three predictors: (1) the modulation maps (MM) from the multi-leaf collimator, (2) the relative monitor units per control point profile (MUcp), and (3) the composite dose image (CDI) used for portal dosimetry, from 1024 anonymized prostate plans. The models’ performance was assessed for classification and regression by the area under the receiver operator characteristic curve (AUC_ROC) and Spearman’s correlation coefficient (r). Finally, four hybrid models were designed using all possible combinations of the three predictors. The prediction performance for the CNN-models using single predictors (MM, MUcp, and CDI) were AUC_ROC = 0.84 ± 0.03, 0.77 ± 0.07, 0.75 ± 0.04, and r = 0.6, 0.5, 0.7. Contrastingly, the hybrid models (MM + MUcp, MM + CDI, MUcp+CDI, MM + MUcp+CDI) performance were AUC_ROC = 0.94 ± 0.03, 0.85 ± 0.06, 0.89 ± 0.06, 0.91 ± 0.03, and r = 0.7, 0.5, 0.6, 0.7. The MP, MUcp, and CDI are suitable predictors for dose deliverability models implementing ML methods. Additionally, hybrid models are susceptible to improving their prediction performance, including two or more input predictors.
Technical Comparison Report on Aerospace Plane Propulsion System
Authors: Li Siwei
Published: November 2022

The aerospace plane is a new type of aircraft used for both aviation and space flight. This paper analyzes the performance requirements of the propulsion system of space airplanes and focuses on the introduction and comparison of the propulsion systems used in three typical aerospace planes. Then, some suggestions are put forward for the subsequent development of the related technology.
3D Mapping and Positioning Technology of Lunar Environment Based on LiDAR
Authors: Du Shi Biao , Zhao Xin , Fu Hong Yong
Published: November 2022

-Using intelligent guidance system for lunar sample collection, Simultaneous lunar environment 3D mapping and localization technology (SLAM) is a key problem to be solved urgently. The lunar illumination changes dramatically and the terrain is complex. And limited computing power of the intelligent guidance system on the moon will affect the positioning accuracy of the algorithm. In view of the low positioning accuracy of LiDAR in the current lunar environment. This paper use an algorithm with higher positioning accuracy, which integrates the front-end feature extraction algorithm, the back-end optimization algorithm based on factor graph and the Scan Context loop closure detection algorithm. The simulation platform of lunar environment is built by Airsim to test the algorithm, and the robustness and accuracy of the algorithm are verified.
Research on optimization of wave glider wing plate
Authors: Wang Ganlin , Zhu Liucun , Wan Hong , Wang Jiyue , Deng Haofeng , He Congwei
Published: November 2022

In this study, a new wing plate was designed for the wave glider. The wing plate A and the wing plate C made of NACA0012 were extracted from the adult green sea turtle in the Pacific Ocean, and a new wing plate B was optimized by optimizing the design of the two, and set the control. Group wings D. In order to improve the utilization rate of wave energy of the wave glider, the hydrodynamic performance of the wave glider wing was studied. At the installation angle of 0-90°, the thrust FX in the forward direction of the four types of wings is simulated and calculated. The results show that at the angle of attack of 6° and 9°, the incoming flow velocity is 0.5m/s, 1m/s, 1.5 At m/s, the hydrodynamic performance of the wing plate increases with the increase of the installation angle. The hydrodynamic performance of the four kinds of wing plates is from good to bad: B-foil, A-foil, C-foil and D-foil. The research results help to understand the hydrodynamic performance of the wing plate, and provide a research basis for improving the wave energy utilization rate of the wave glider.
Research on global calibration technology of pressure sensitive paint based on airtight chamber
Authors: Shang Jinkui , Zhao Ronghuan , Xu Zhaonan , Zhong Hongjie
Published: November 2022

Pressure sensitive paint (PSP) technology has been widely applied in wind-tunnel test. Generally, PSP calibration data are obtained using a calibration sample in laboratory priori calibration device, which the sample is sprayed at the same time with the test model.In this study, taking the real test model as the calibration object, a global calibration technology of PSP coating on the surface of the test model is proposed, which is verified in the airtight chamber, and the effective PSP calibration data are obtained. A two-component fast response PSP coating was used in the study. In the validation test, a flying wing model is used, the flying wing model sprayed with PSP coating was placed in the airtight chamber. 11 groups of calibration tests were carried out in the environment of 0.06 MPa ~ 0.14 MPa and 30°C ~50°C, and the calibration curves obtained showed good consistency.
Physical and Chemical Analysis of Contact Points of relay on EMU
Authors: Sun Ping , Zhang Junying , Dong Anji , Zhang Lei , Wang Wenjun , Wu Nan , Dou Abo
Published: November 2022

Electromagnetic relay is an essential part in electric control system on EMU. Because of frequent operation of on-off, external vibration, temperature rising and corrosive gas, etc when the EMU is in operation may cause wear and oxidation of the surface of contact points. Therefore, the electrical contact resistance increased, which cause contact electrical performance failure. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) was used to observe and measure the surface and section of contact points. The experimental result shows that the surface layer wear and contained phosphate and the section contained O, F, S, P, Ag, Ni elements. Thereafter the mechanism of efficacy losing of electromagnetic relay was discussed.
Application Research of Civil Aviation High Frequency Communication System
Authors: Si Kaikai , Lu Qing , Guo Xiaoyan , Gao Bin
Published: November 2022

High frequency communication system is an important part of civil aviation radio communication system. This paper introduces the typical structure and function of civil aircraft high frequency communication system. Discussing the high frequency system architecture mainly and introducing the components of aircraft high frequency transceiver, high frequency coupler and antenna in detail. This paper discusses its principle and function, so as to provide some reference for the design of civil aviation high frequency communication system.
The Bellows Designing Method of Divided Working Conditions for Launch Vehicle
Authors: Zhang Yi , Li Xu , Wang CongFei , Huang Wei , Shi Gang , Wang Yi
Published: November 2022

The working environment of the pipeline system of the launch vehicle is very complex. Bellows in piping system should endure high temperature, corrosive medium, vibration and other conditions, which require for high reliability. However, due to the restrictions of fixed location, weight reduce requirement, the number and location of bellows are strictly required. There is a great difference for the bellows design method between the launch vehicle and the ground pipeline. In this paper, a bellows designing method for launch vehicle is introduced in detail. The method calculates the compensation amount of bellows under divided working conditions, and checks the fatigue damage coefficient as the main failure judgement basis. It has been proved by practice that the designing method of divided working conditions can solve the design problems of the bellows of launch vehicles effectively.
Dynamic pressure-based rocket PID parameters adaptive adjustment method and application
Authors: Zhao Meng , Zhang Yifan , Tao Zhengxin , Liu Yiyue , Li Runqi , Peng Ke
Published: November 2022

This paper establishes a dynamic pressure-based PID parameter adjustment method, which uses the function of the ratio of the maximum dynamic pressure of the rocket to the actual dynamic pressure of the current flight to correct the rocket control parameters. Compared with the traditional time-based PID parameter gain scheduling method, the number of PID parameters to be adjusted is significantly reduced from nearly 50 to 10, and the adjustment complexity is significantly reduced. Based on the method in this paper, the PID parameter debugging of the attitude control of a model-guided rocket is completed. The six-degree-of-freedom ballistic simulation results show that the control law obtained by the method in this paper meets the requirements of the attitude control of the model-guided rocket, and is superior to the traditional time-based PID parameter gain adjustment method in terms of response rate.
The category of black holes and state-of-art detection scenarios
Authors: Peng Zhenyu
Published: November 2022

The existence of black holes has been proposed for more than two centuries. Contemporarily, plenty of milestones have been achieved in this field, e.g., the first image of the black holes and the launch of the James Webb Space Telescope. This paper focuses on the organization of recent achievements in this field including three main parts: the history and fundamental concepts of the black holes; the classification of different black holes through their physical qualities; and progresses in this decade. These results shed light on the technical developments of the ability to detect black holes, which is beneficial to further research in the future.
Numerical study of air-breathing two-phase rotating detonation engine under Ma 6 flight conditions
Authors: Yan Chenglong , Lin Wei , Shu Chen , Zhi Yue , He Wei
Published: November 2022

Air-breathing two-phase rotating detonation engines possess high thermodynamic cycle efficiency and have attracted extensive attention in domain of wide range flight aircraft. In this study, an engine configuration is proposed, and the corresponding numerical model is established using the Euler-Lagrange method. The engine type is suitable for flying at an altitude of 28 kilometers and a flying speed of Ma 6. Our data show that the engine operates primarily in chaos in this flight state. The peak pressure of the detonation wave is about 0.85 MPa, the peak temperature of the detonation wave is about 4500 K, the average thrust of the engine is 2637 N, and the average fuel-specific impulse is about 2989 s.
Numerical Simulation of Jet Interaction Flow Field with Different Flow Rates
Authors: Liu Yuwei , Wang Xinchen , Li Kangkang , Liu Yaofeng
Published: November 2022

In this paper, the complex disturbance flow caused by the interaction of jets with different flow rates and hypersonic incoming flow on a cone-cylinder-skirt of revolution is numerically studied, the typical shock wave structure and the influence range caused by the jet interaction are given, and the effect of the jet flow rate on the interaction flow field is discussed. The results show that the interaction between the jet flow and the incoming flow increases with the rise of the jet flow rate, and the influence range of the wrapping effect enlarges. If the jet flow rate is equivalent to the incoming flow rate, the leading edge separation line forms a closed loop.
Classification of Schmidt-rank-two multipartite unitary gates by singular number
Authors: Shen Yi , Chen Lin , Yu Li
Published: November 2022

The multipartite unitary gates are called genuine if they are not product unitary operators across any bipartition. We mainly investigate the classification of genuine multipartite unitary gates of Schmidt rank two (SR-2), by focusing on the multiqubit scenario. For genuine multipartite (excluding bipartite) unitary gates of SR-2, there is an essential fact that their Schmidt decompositions are unique. Based on this fact, we propose a key notion named as singular number (SN) to classify the unitary gates concerned. The SN is defined as the number of local singular operators in the Schmidt decomposition. We then determine the accurate range of SN. For each SN, we formulate the parametric Schmidt decompositions of genuine multiqubit unitary gates under local equivalence. Finally, we extend the study to three-qubit diagonal unitary gates due to the close relation between diagonal unitary gates and SR-2 unitaries. We start with discussing two typical examples of SR-2, one of which is a fundamental three-qubit unitary gate, i.e. the CCZ gate. Then we characterize the diagonal unitary gates of SR greater than two. We show that a three-qubit diagonal unitary gate has SR at most three, and present a necessary and sufficient condition for such a unitary gate of SR-3. This completes the characterization of all genuine three-qubit diagonal unitary gates.
Random sampling in reproducing kernel spaces with mixed norm
Authors: Li Yaxu
Published: November 2022

In this work we consider random sampling of signals in (in)finite-dimensional reproducing kernel spaces with mixed norm. Here the random sampling refers to randomly taken sampling positions according to some probability measure. We study the stability of random sampling procedure by establishing sampling inequality that holds with high probability when the sampling size is large. We establish the probabilistic sampling inequality though a combination of mathematical analysis and probabilistic analysis. The main tools we use are covering number of signal (function) space and (uniform) large deviation inequality for a sequence of random variables. We provide a concise proof and our proof leads to explicit and transparent estimates involved in the probability with which the sampling inequality holds.
Prevalence and Level of Occupational Exposure to Asbestos in Canada in 2016
Authors: Fenton Shelby , Rydz Ela , Demers Paul A , Peters Cheryl E
Published: November 2022

Objective

Asbestos use has decreased over time but occupational exposure still exists today due to the presence of asbestos in older buildings. The objective of this study was to update CAREX Canada’s prevalence of exposure estimate from 2006 to 2016, and to assess the level of occupational exposure by industry, occupation, province/territory, and sex.

Methods

Estimates by occupation, industry, province/territory, and sex were calculated using labor force data from the 2016 Census of Population and proportions of workers exposed by occupation and industry, which were previously developed for the 2006 estimates and updated here to reflect new knowledge and changes in exposures. Statistics Canada concordance tables were used to account for changes between the 2006 and 2016 job and industry coding systems. Expert assessment was used to qualitatively assign levels of exposure (low, moderate, or high) for each occupation and industry, with consideration of workers’ proximity and access to asbestos-containing material, and the condition and content of asbestos.

Results

Approximately 235 000 workers are exposed to asbestos on the job in Canada. The majority of Canadian workers exposed to asbestos are male (89%). Only 5% of all exposed workers are in the high-exposure category, while most workers are in the low (49%) or moderate (46%) exposure categories. The construction sector and associated jobs (e.g. carpenters, trades helpers and laborers, electricians) accounted for the majority of exposed workers.

Conclusions

Occupational exposure to asbestos continues to occur in Canada. Updating the prevalence of exposure estimate and adding exposure levels highlights the shift from high to lower-lever exposures associated with asbestos-containing materials remaining in the built environment.
On international arbitration, choice of substantive law, and the CISG: a case law study
Authors: Favero Vaughn Gustavo , Duggal Kabir
Published: November 2022

This article analyses past arbitral decisions concerning disputes related to the international sale of goods. It also explores when and how arbitrators should apply the CISG as the substantive law to resolve the merits of these disputes. This article takes into account three different scenarios in determining the applicable substantive law: (i) when parties choose the applicable substantive law; (ii) when there is no choice of law by the parties, and the arbitrators apply the indirect method; and (iii) when there is no choice of law by the parties, the arbitrators apply the direct method. In a nutshell, it is our submission that arbitrators’ should respect the laws chosen by the parties and, if the CISG applies by virtue of this choice, then arbitrators should not circumvent the use of the CISG.
In silico versus functional characterization of genetic variants: lessons from muscle channelopathies
Authors: Vivekanandam Vinojini , Ellmers Rebecca , Jayaseelan Dipa , Houlden Henry , Männikkö Roope , Hanna Michael G
Published: November 2022

Accurate determination of the pathogenicity of missense genetic variants of uncertain significance is a huge challenge for implementing genetic data in clinical practice. In silico predictive tools are used to score variants’ pathogenicity. However, their value in clinical settings is often unclear, as they have not usually been validated against robust functional assays. We compared nine widely used in silico predictive tools, including more recently developed tools (EVE and REVEL) with detailed cell-based electrophysiology, for 126 CLCN1 variants discovered in patients with the skeletal muscle channelopathy myotonia congenita. We found poor accuracy for most tools. The highest accuracy was obtained with MutationTaster (84.58%) and REVEL (82.54%). Both of these scores showed poor specificity, although specificity was better using EVE. Combining methods based on concordance improved performance overall but still lacked specificity. Our calculated statistics for the predictive tools were different to reported values for other genes in the literature, suggesting that the utility of the tools varies between genes. Overall, current predictive tools for this chloride channel are not reliable for clinical use, and tools with better specificity are urgently required. Improving the accuracy of predictive tools is a wider issue and a huge challenge for effective clinical implementation of genetic data.
Cytomegalovirus infection is associated with rapid NK differentiation and reduced incidence of relapse in HLA matched sibling donor transplant patients
Authors: Han Tingting , Xie Juan , Zhao Xiaosu , Lv Meng , Chang Yingjun , Xu Lanping , Wang Yu , Zhang Xiaohui , Liu Kaiyan , Huang Xiao-Jun , Zhao Xiang-Yu
Published: November 2022

The effect of cytomegalovirus (CMV) infection on leukemia relapse and the potential mechanism remains controversial. In this retrospective study, we evaluated the association among CMV infection, NK reconstitution and clinical outcomes in consecutive patients with hematologic malignancy who underwent HLA matched sibling donor transplantation (MST). In total, 228 patients were enrolled in the study between January 2010 and December 2011. The cumulative incidence of CMV infection on day 100 post-HSCT was 13.6 ± 4.9%. The probabilities of OS and DFS were 45.4% vs. 71.7% (P = 0.004) and 43.9% vs. 64.2% (P = 0.050) in the patients with CMV infection and without CMV infection, respectively. The cumulative incidence of treatment-related mortality (TRM) and relapse at 5 years was 48.6 ± 9.6% vs. 11.5 ± 2.9% (P < 0.001) and 6.2 ± 4.3% vs. 29.2 ± 3.9% (P = 0.024) in the patients with CMV infection and without CMV infection, respectively. In the multivariate analysis, CMV infection was associated with higher TRM, lower OS, and lower DFS. In addition, we found that CMV infection may promote the recovery of the absolute number of NK cells and promote the differentiation of NK cells post-MST. In conclusion, CMV infection may promote the recovery and differentiation of NK cells and was correlated with a lower relapse rate post-MST.
Moral hazard in the British bovine tuberculosis control programme
Authors: Scheitrum Daniel P , Schaefer K Aleks , van Winden Steven
Published: November 2022

Animal disease indemnity payments create a moral hazard problem by diminishing the financial burden of on-farm infection which, in turn, can reduce private incentives to invest in biosecurity. The economic importance of the moral hazard problem is a function of the size of the indemnity payment relative to market prices and input costs, as well as farm-specific disease risks and the probability that biosecurity efforts can reduce those risks. We investigate the importance of these contributory factors on disease outcomes in the context of the British bovine tuberculosis control programme using longitudinal herd-level data for all beef cattle herds in Great Britain. We show that, by disincentivising biosecurity investment, increases in disease indemnity payments lead to more on-farm breakdowns, increase the number of on-farm disease reactors and extend the duration of infection. Our findings suggest that the disease burden created through these unintended consequences accounts for approximately one-fourth of the additional programme outlays associated with a 10% increase in the per-head indemnity payment.
Microcontextual considerations in ouster clause analysis: A comparative study of parallel trends in the United Kingdom and Singapore
Authors: Chng Kenny
Published: November 2022

The classic legal approach to legislative ouster clauses in the common law was articulated by the House of Lords in Anisminic Ltd. v. Foreign Compensation Commission. However, recent developments in both the United Kingdom and Singapore indicate a judicial desire to shift away from that approach towards a more flexible analysis of an ouster clause’s effect, centered on the rule of law. This article highlights the significance of those parallel developments, especially given the starkly differing constitutional contexts shaping the approach to ouster clauses in the two jurisdictions. Capitalizing on these trends, it proposes a comparative assessment of the materiality of various microcontextual considerations in ouster clause analysis in the two jurisdictions—considerations such as the nature of the subject matter and the characteristics of the decision-maker—and inquires into the normative implications in each jurisdiction of these developments in ouster clause doctrine.