bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐speed target imaging for vortex electromagnetic wave radar
Authors: Zhou Yu‐Ang , Zhu Yong‐Zhong , Chen Yi‐Jun , Zhao He‐Feng , Xie Wen‐Xuan 
Published: October 2021

AbstractVortex electromagnetic waves (VEMWs) carrying orbital angular momentum (OAM) are promising to benefit the higher degree of freedom for inverse synthetic aperture radar (ISAR) imaging on account of their helical wavefront. For high‐speed targets, the ‘stop and go’ hypothesis is no longer valid. Thus, the intrapulse movement of the target will cause the broadening and shift of the one‐dimensional range profile and the blurring of the OAM eigenvalues coupling azimuth. This contribution proposes a high‐speed target imaging method for the VEMW ISAR. First, an OAM‐based ISAR imaging model for high‐speed targets is derived and the echo characteristics are analysed. Subsequently, in order to effectively estimate the ratio of the echo to correct the imaging result, an estimation method that takes into account the calculation speed and accuracy is proposed. On this basis, the target velocity distribution obtained under multiple echoes is analysed to improve the accuracy of the results. Finally, the range profile and azimuthal profile are reconstructed. Compared with the existing vortex electromagnetic imaging algorithm, the proposed method can effectively eliminate the influence of high‐speed motion on the range and azimuth profile. This work provides suggestions for the development of EM vortex ISAR imaging technology.
Low elevation target altitude measurement for ubiquitous radar based on known transmitted waveform and sparse representation
Authors: Guo Rui , Peng Xiangyu , Tian Biao , Zhang Yue , Chen Zengping 
Published: October 2021

AbstractThe multipath effect deteriorates the performance of low elevation target altitude estimation with a ubiquitous radar strongly, especially in complex terrain environments in which multiple reflection paths exist simultaneously. This work shows how the authors reconstructed a multipath model for ubiquitous radar with a known waveform and took advantage of it to improve the altitude measurement performance when locating low‐altitude small targets in complex terrain environments. The authors first present a multipath propagation model for target elevation angle estimation in which not only received multipaths but also transmitted multipaths are taken into consideration. Then, a reconstructed elevation angle estimation model in which the waveform is known and the target elevation information is as same as the original model is derived. Finally, an innovative low elevation angle estimation algorithm based on a maximum likelihood estimator and a sparse representation is proposed. Simulations and experiment results verify that the proposed algorithm has a much more robust low elevation angle estimation performance than existing methods in complex terrain environments. Index Terms—Target altitude measurement, complex multipath effect, known transmitted waveform, sparse representation, ubiquitous radar.
Laboratory observation and astronomical search of 1-cyano propargyl radical, HCCCHCN
Authors: Cabezas C. , Nakajima M. , Chang C. H. , Agúndez M. , Endo Y. , Cernicharo J. 
Published: October 2021

Context. The reaction between carbon atoms and vinyl cyanide, CH2CHCN, is a formation route to interstellar 3-cyano propargyl radical, CH2C3N, a species that has recently been discovered in space. The 1-cyano propargyl radical (HC3HCN), an isomer of CH2C3N, is predicted to be produced in the same reaction at least twice more efficiently than CH2C3N. Hence, HC3HCN is a plausible candidate to be observed in space as well.
Aims. We aim to generate the HC3HCN radical in the gas phase in order to investigate its rotational spectrum. The derived spectroscopic parameters for this species will be used to obtain reliable frequency predictions to support its detection in space.
Methods. The HC3HCN radical was produced by an electric discharge, and its rotational spectrum was characterized using a Balle-Flygare narrowband-type Fourier-transform microwave spectrometer operating in the frequency region of 4–40 GHz. The spectral analysis was supported by high-level ab initio calculations.
Results. A total of 193 hyperfine components that originated from 12 rotational transitions, a- and b-type, were measured for the HC3HCN radical. The analysis allowed us to accurately determine 22 molecular constants, including rotational and centrifugal distortion constants as well as the fine and hyperfine constants. Transition frequency predictions were used to search for the HC3HCN radical in TMC-1 using the QUIJOTE survey between 30 and 50 GHz. We do not detect HC3HCN in TMC-1 and derive a 3σ upper limit to its column density of 6.0 × 1011 cm−2.
Linking high- and low-mass star formation
Authors: Pitts R. L. , Kristensen L. E. , Jørgensen J. K. , van der Walt S. J. 
Published: October 2021

Context. Astronomers have yet to establish whether high-mass protostars form from high-mass prestellar cores, similar to their lower-mass counterparts, or from lower-mass fragments at the heart of a pre-protostellar cluster undergoing large-scale collapse. Part of the uncertainty is due to a shortage of envelope structure data on protostars of a few tens of solar masses, where we expect to see a transition from intermediate-mass star formation to the high-mass process.
Aims. We sought to derive the masses, luminosities, and envelope density profiles for eight sources in Cygnus-X, whose mass estimates in the literature placed them in the sampling gap. Combining these sources with similarly evolved sources in the literature enabled us to perform a meta-analysis of protostellar envelope parameters over six decades in source luminosity.
Methods. We performed spectral energy distribution fitting on archival broadband photometric continuum data from 1.2 to 850 μm to derive bolometric luminosities for our eight sources plus initial mass and radius estimates for modelling density and temperature profiles with the radiative-transfer package Transphere.
Results. The envelope masses, densities at 1000 AU, outer envelope radii, and density power law indices as functions of bolometric luminosity all follow established trends in the literature spanning six decades in luminosity. Most of our sources occupy an intermediate to moderately high range of masses and luminosities, which helps to more firmly establish the continuity between low- and high-mass star formation mechanisms. Our density power law indices are consistent with observed values in the literature, which show no discernible trends with luminosity, and have a mean p = −1.4 ± 0.4. However, our sub-sample, with a mean power law index of −1.1 ± 0.3, is slightly flatter than would be expected for spherical envelopes in free fall (p = −1.5).
Conclusions. We attribute flattened density profiles for our eight sources to one or more of the following: ongoing accretion from their natal filaments, convolution of sources with neighbours or the larger filament, spherical averaging of asymmetric features (for example fragments), or inflation of the envelope by a moderate far-ultraviolet field. Finally, we show that the trends in all of the envelope parameters for high-mass protostars are statistically indistinguishable from trends in the same variables for low-mass protostars.
Feasibility analysis of an innovative naval on-board power-train system with hydrogen- based PEMFC technology
Authors: Di Micco Simona , Minutillo Mariagiovanna , Forcina Antonio , Cigolotti Viviana , Perna Alessandra 
Published: October 2021

The maritime transportation sector is one of the main contributors to global emissions of greenhouse gases (GHGs), volatile organic compounds (VOCs), particulate matter (PM), hazardous air pollutants, NOX and SOX. In particular, it is estimated that the CO2 emissions in this sector are about 1 Gt every year.
The International Maritime Organization (IMO) adopted stringent emission limits in its Tier III regulation, most notably on NOX and SOX emissions and pledged to reach a reduction in greenhouse gas (GHG) emissions from international shipments by at least 50% by the year 2050, compared to 2008 emissions. For emission control areas (ECAs) these requirements are particularly strict and will be difficult to meet with traditional diesel engines and bunker fuels. Therefore, ship owners need to adopt solutions to bring emissions within these and other future limits by means of environmentally friendly fuels and high efficiency propulsion technologies. In this context, hydrogen and fuel cells play a crucial role, thanks to their low criteria pollutant and GHG emission.
This paper presents a techno-economic feasibility study for replacing the conventional diesel engine powertrain, usually employed in Ro-Pax ferries, with an innovative system based on polymer electrolyte membrane fuel cell (PEMFC) technology. The ferry is actually powered by four diesel engines, which deliver a total output of 37.8 MW. The ferry also has two auxiliary engines which give an output of 4.0 MW and also two 2.0 MW bow thrusters for its manoeuvring. The energy analysis has allowed to define the hydrogen consumption for each cruise, as well as the optimal size of the innovative propulsion system. In particular, The PEMFC powertrain is sized at the same maximum power output as the main diesel engine and, thanks to the modular architecture of fuel cells and their flexible performance at partial load, the auxiliary engines are not contemplated. Moreover, in order to identify the best solution in terms of ship’s weight and space requirements, two hydrogen storage solutions based on compressed hydrogen technology and liquefied hydrogen technology, have been analyzed and compared. The economic assessment has been carried out by estimating the CAPEX and OPEX for each H2 storage technology by considering short-term, mid-term and long-term scenarios (from 2020 to 2050).
Grinder Injury of the Hand: A Rare but Devastating Occupational Hazard
Authors: Patial Tushar , Mittal Rajinder K. , Garg Ramneesh , Shah Sheerin , Kaur Amandeep 
Published: October 2021

AbstractFood handlers and workers are exposed to several occupational hazards not frequented by the general population. Grinder injuries of the hand present a devastating consequence of industrial food processing that is infrequently described. Herein, we describe two cases that presented to our department with meat grinder injuries of the hand.
Towards energy policy corporatism in Central and Eastern Europe?
Authors: Horváthová Brigitte , Dobbins Michael , Labanino Rafael Pablo 
Published: October 2021

AbstractThis paper contributes to our understanding of interest intermediation structures in Central and Eastern Europe (CEE) and, specifically, whether, which, how and to what extent organized interests are incorporated into policy-making processes. Unlike previous studies primarily focusing on patterns of economic coordination (Jahn 2016), we focus on energy policy-making in the Czech Republic, Hungary, Poland and Slovenia. We address the extent to which these energy interest intermediation systems are gravitating towards a more corporatist policy-making paradigm and whether corporatist arrangements have been dismantled in view of the new wave of national conservatism in CEE. We offer a complex operationalization of corporatism based on concrete indicators and present the results of a survey of energy interest groups operating in the region. It covers questions regarding interest intermediation between the organized interests and the government, regulatory authorities as well as the degree of policy coordination and political exchange with the state and between rivalling organizations, enabling us to derive a “corporatism score” for each national institutional setting and discuss them in the light of Jahn’s (2016) corporatism rankings for the region. We show that—despite striking differences—at least rudimentary corporatist interest intermediation structures have emerged with some variations of pluralism and statism in all four countries.
Partial substitution of barley with maize meal or flaked meal in bovine diets: effects on fatty acid and α-tocopherol concentration and the oxidative stability of beef under simulated retail display
Authors: Siphambili S. , Moloney A. P. , O’Riordan E. G. , McGee M. , Harrison S. M. , Monahan F. J. 
Published: October 2021

Context Different cereal grain sources may be used in beef production but little is known about their effects on beef quality. Aims This study evaluated fatty acid composition, α-tocopherol concentration and oxidative stability of beef from bulls fed barley or a combination of barley and either ground or toasted flaked maize. Methods Fatty acid composition, α-tocopherol concentration, lipid oxidation and colour stability were measured in beef from late maturing bulls finished on a barley-based concentrate (BC) or on the concentrate with barley partially replaced by either maize meal (MM) or flaked meal (FM). Samples of M. longissimus thoracis were subjected to simulated retail display (4°C) for 3, 7, 10 and 14 days in modified atmosphere packs (O2:CO2; 80:20). Muscle was analysed for fatty acid and α-tocopherol concentrations, colour stability and lipid oxidation. Key results There were differences in the fatty acid concentrations. Total fatty acids, monounsaturated fatty acids and saturated fatty acids were higher (P < 0.05) in muscle from BC compared to FM bulls but neither were different to MM bulls. A decrease (P < 0.05) in concentration following display was observed across all treatments for α-tocopherol, C15:1, C18:2 n-6c, C18:3 n-3, C20:3 n-6, C20:4 n-6, C22:2, C20:5 n-3, C22:5 n-3, C22:6 n-3, total polyunsaturated fatty acids (PUFA), n-6 PUFA, n-3 PUFA and highly peroxidisable PUFA. Lipid oxidation in muscle was higher (P < 0.01) in muscle of FM compared to MM bulls after 14 days of refrigerated storage but neither were different to BC bulls. There was no difference (P > 0.05) in colour stability of muscle due to dietary treatment. Conclusions Partial replacement of barley with maize in the diet of bulls influences muscle fatty acid concentration and profile, leading to a marginal increase in lipid oxidation with no detrimental effect on colour stability. Implications Toasted-flaked or ground maize may partially substitute for rolled barley in a concentrate ration without affecting colour stability of meat under retail display conditions. The slight increase in lipid oxidation, after prolonged storage, in beef from bulls fed flaked toasted maize is unlikely to be of significance from a product acceptability perspective.
A language-matching model to improve equity and efficiency of COVID-19 contact tracing
Authors: Lu Lisa , Anderson Benjamin , Ha Raymond , D’Agostino Alexis , Rudman Sarah L. , Ouyang Derek , Ho Daniel E. 
Published: October 2021

Significance
Language discordance has been shown to contribute to social disparities in healthcare. Contact tracing is essential to combating COVID-19, but language differences between contact tracers and patients have hindered its efficacy. We demonstrate a general method for leveraging machine learning and administrative data to maximize the impact of bilingual contact tracers and level language differences. We evaluate in a randomized controlled trial the impact of language matching on high-volume contact tracing in Santa Clara County, CA, and show that it reduces time spent and improves engagement with contact tracers. These results illustrate the advantages of utilizing bilingual personnel over third-party interpreters in improving social services.
Control of radiation-driven tearing mode by externally driven current in tokamaks
Authors: Xu Hai-Wen , Song Yuan-Hong , Ma Zhi-Wei , Wang You-Nian 
Published: October 2021

Abstract
The radiation-driven tearing mode (RTM) in tokamaks was numerically studied in our previous investigation (Xu et al 2020 Plasma Phys. Control. Fusion
62 105009), and it was noticed that radiation cooling could drive magnetic island growth and could even cause disruption due to the nonlinear mode coupling. In this work, the suppression of the radiation-driven

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tearing mode by an externally driven current is investigated numerically by using a three-dimensional toroidal code CLT (Ci-Liu-Ti means magnetohydrodynamics in Chinese) based on a full set of resistive magnetohydrodynamic equations. It is found that an externally driven current with appropriate turn-on time and strength can effectively stabilize the RTM. The effects of the asymmetry current and multi-mode coupling can be stabilized effectively by the externally driven current. In the nonlinear stage, under the influence of the radiation, a strong

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mode is generated due to the hot-core shift caused by the decrease of the core thermal pressure, which is irreversible even if the

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magnetic island could be effectively controlled by the externally driven current. When the externally driven current is turned on in the linear stage, it very efficiently and quickly suppresses the dominant modes, and the hot-core shift effect also becomes weaker because of the smaller

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mode. Moreover, it is found that external auxiliary heating with appropriate intensity in the core region can effectively balance the reduced pressure and can further control the hot-core shift caused by radiative cooling.
Iterative technique for a beam lying on a transversely isotropic foundation
Authors: Yue F , Wu Z Y 
Published: October 2021

Abstract
The effect of the foundation heterogeneity on the mechanical behaviour of a beam on Vlasov soils is discussed. According to a refined Vlasov soil model, the static problem of beams lying on transversely isotropic soils can be solved by an iterative method. In this paper, based on the energy variational principle, the differential equations for beams under an axial force on refined Vlasov foundations are derived. The methods for solving the internal forces and deformations of beams lying on refined elastic foundations are given. Additionally, an equation for the attenuation parameters is also established, and the characteristic parameters of the refined model are solved by iterative technique. Numerical results show that the foundation heterogeneity have a influence on the deformations and internal forces of the beam-soil system. Moreover, relatively accurate characteristic parameters can be obtained through the iterative process. The refined Vlasov model has broad application prospects.
Additive remanufacturing of coupler knuckle based on robotic gas metal arc welding
Authors: Wang F , Yin Z Q , Sun X H , Gong X D , Kou L , Zhan Z T , Ni X H , Yuan X J , Meng Y X , Liang G Q , Feng X C , Li X J , Gao J L 
Published: October 2021

Abstract
Take the wear parts of coupler knuckle as an example, the “Modeling—Slicing — Stacking” mode remanufacturing process is studied. First, the 3D model of the of the worn coupler knuckle surface is acquired by structured light 3D detection. The remanufacturing model of the failure part is built by Boolean operation between the original model and the acquired 3D model. Second, the user can slice layer of the remanufacturing model according to the remanufacturing stacking parameters. The zone that surrounded by the contour of each sliced layer is the robotic GMAW remanufacturing stack region. Third, the robotic GMAW remanufacturing path is planed within the region mentioned above and the executable program is generated to carry out the remanufacturing task layer by layer. Moreover, the worn coupler knuckle was repaired by adopting Robotic GMAW Process. The mechanical performances of component were tested, the results indicate that the remanufactured coupler knuckle satisfying the operating requirements.
Experimental Study on the Effect of C-PAM and A-PAM on Dewatering Performance of Waste Mud
Authors: Du C L , Peng M G , Li Z W , Zhou S X , Ren L Z , Duan J C , He M X , Wang M 
Published: October 2021

Abstract
Abstract:In order to improve the treatment capacity of waste mud, C-PAM and A-PAM were used to treat waste mud in this paper. The effects of C-PAM and A-PAM on the flocculation effect of waste mud were discussed. The key mechanisms of C-PAM and A-PAM on the flocculation of waste mud were deeply analyzed by analyzing the variation characteristics of particle size distribution, water content of filter cake, Zeta potential of supernatant and turbidity of supernatant during the treatment process. The results showed that the flocculation effect was the best when the dosages of C-PAM and A-PAM were 140 mL (2%) and 30 mL (2%), respectively. The adsorption bridging of C-PAM and A-PAM plays a leading role in the treatment of waste mud, but the electric neutralization is not obvious. This research can reduce the amount of waste mud and has practical significance.
The Release of C-14 of HTR Graphite Spheres during High Temperature Oxidation
Authors: Chen X , Liu B , Wang T , Xu G , Zhang L , Mao C , Xiao H , Shao Y , Zhao H , He L , Yin Z 
Published: October 2021

Abstract
As the key components of the HTGR fuel, the intact TRISO-coated particles contain almost all fission products under the normal and accident conditions in the reactor. On the other hand, the high temperature oxidation of irradiated fuel pebbles is one of feasible processing methods for HTR spent fuel pebbles. The knowledge of the C-14 release from irradiated fuels and the migration behavior during high temperature oxidation is of great importance for the post-irradiation examinations (PIE) and long-term storage and reprocessing of HTR-PM fuel pebbles. In this work, the C-14 release behavior from one irradiated HTR graphite sphere, which was used as a substitute for a irradiated HTR fuel, was determined by out-of-pile examination. The irradiated HTR fuel was oxidized in the hot lab of INET, and the substantial migration of fission products from graphite matrix was adsorbed and systematically studied by γ-scanning. Specifically, the C-14 release during oxidation was analyzed and illustrated. This work will provide theory and experiment basement for spent fuel disposal of HTGR, as well as a new sample preparation method for C-14 measurement by liquid scintillation counter (LSC).
Release Rates of Short-lived Fission Gases from Modern Spherical Fuel Elements with TRISO-coated Particles
Authors: Verfondern K , Liu B , Nabielek H , Wang T , Allelein H J , Tang C H 
Published: October 2021

Abstract
Measurement and prediction of fission product release is important in design, licensing and operation of HTRs. Latest development status is near zero particle manufacturing defects and in-pile failures combined with very low matrix contamination levels. In-pile Release over Birth rate measurements will be described and evaluated. Quantitative predictive analyses of short-lived gas release will be provided for MTR irradiation testing with a focus on the most recent experiment with Chinese fuel from HTR-PM production. For irradiation tests with no single particle failure, models describing particle kernel release are not applicable; instead modeling of matrix contamination release is essential. Good agreement between post calculations and in-line R/B measurements has been achieved.