bluuebunny/crossref_metadata_2025 huggingface dataset:
A dynamic data prepossessing method for parameter identification in power distribution network
Authors: Wang Chuanjun , Xiang Wei , Hu Ke , Li Bin
Published: April 2023

The methods of building a model like Markov chain Monte‐Carlo (MCMC) and sequential model‐based global optimization (SMBO) in power distribution network (PDN) have achieved parameter identification successfully without extra measurement devices. However, the data processing focused on the feeder data is not concerned yet. In this study, the authors present a dynamic data prepossessing method for parameter identification in PDN to successfully obtain a more accurate result. This method considers the similarities of feeder data in both spatial relationship and statistical theory, and then realizes a dynamic aggregation process for new coming data and obtains a set of data with tighter higher dimensional relationship for following identification task. In experiments, the authors applied this data processing method to the actual feeder data with no adjustment of the other condition; identification results with the authors’ processing achieve a 5.3% improvement in accuracy at most.
Fault diagnosis of ZDJ7 railway point machine based on improved DCNN and SVDD classification
Authors: Shi Zengshu , Du Yiman , Yao Xinwen
Published: April 2023

Problems such as poor noise immunity and overfitting are prone to occur when convolutional neural network (CNN) is exploited in the fault diagnosis of ZDJ7 railway point machine. In addition, some fault features are unbalanced and have the features of multiple tags, which lead to low diagnosis accuracy. Therefore, an improved deep convolutional neural network (DCNN) and support vector data description (SVDD) classification is proposed. First, the depthwise separable convolution in the Xception structure is used to optimize the extraction of fault features. Second, the adaptive batch normalization processing (AdaBN) is performed to improve the noise immunity. Meanwhile, the global average pooling layer (GAP) is used instead of the fully connected layer to improve the generalization ability of the network. Aiming at the unbalanced features of the railway point machine sample, an improved quantity learning algorithm for hypersphere coordinate mapping based on SVDD is proposed. The classification is realized under unbalanced samples. The experiment shows that the accuracy based on the improved DCNN and SVDD is 96.59%. It has a good anti‐noise performance under different convolution kernels and SNRs. When the sample distribution is unbalanced, the performance indexes obtained by the proposed model are the best.
Coupling analysis on power‐frequency control loops for virtual synchronous generator based on relative gain array and Prony method
Authors: Jia Jiaoxin , Yan Xiangwu , Qin Benshuang
Published: April 2023

With the improvement of the penetration of power electronic equipment, a challenging scenario is arising in power‐frequency control system design of virtual synchronous generator (VSG). This affects the stability and control performance of the multi‐VSG grid‐connected system due to the undesirable dynamic coupling of the power‐frequency control loops. From this perspective, this paper proposes a systematic procedure for accurately evaluating the coupling of power‐frequency control loop, which is based on the relative gain array (RGA) and Prony analysis method. Firstly, the output admittance model of multi‐VSG grid‐connected system is established, and the transfer function matrices of output power and angular frequency are derived, respectively. Then, the variation law of coupling between control loops of VSG with different parameters is investigated by two methods: One is numerical analysis, and the other is RGA method which can determine the frequency band of coupling. Besides, the interaction between different VSG control strategies is compared and analyzed based on RGA. Subsequently, Prony analysis method is proposed to verify the results of RGA analysis. Finally, simulation and experimental results in a two‐machine grid‐connected system are presented to support the theoretical analysis and demonstrate the feasibility of the proposed method.
CIDFuzz: Fuzz testing for continuous integration
Authors: Zhang Jiaming , Cui Zhanqi , Chen Xiang , Yang Huiwen , Zheng Liwei , Liu Jianbin
Published: April 2023

As agile software development and extreme programing have become increasingly popular, continuous integration (CI) has become a widely used collaborative work method. However, it is common to make changes frequently to a project during CI. If existing testing methods are applied to CI directly, it will be difficult to make testing resources focus on changes generated by CI, which results in insufficient testing for changes. To solve this problem, we propose a fuzz testing method for CI. First, differential analysis is performed to determine the change points generated during CI, change points are added to the taint source set, and static analysis is conducted to calculate the distances between each basic block and the taint sources. Then, the project under test is instrumented according to the distances. During fuzz testing, testing resources are allocated based on seed coverage to test the change points effectively. Using the proposed methods, we implement CIDFuzz as a prototype tool, and experiments are conducted on four open‐source projects that use CI. Experimental results show that, compared with AFL and AFLGo, CIDFuzz can reduce the time costs of covering change points up to 39.59% and 41.64%, respectively. Also, CIDFuzz can reduce the time costs of reproducing vulnerabilities up to 34.78% and 25.55%.
The forming biomass energy rod from the leaf sheath of sugarcane during drying process using microwave energy
Authors: Keangin Pornthip , Charoenlerdchanya Aphisara
Published: April 2023

The leaf sheath of sugarcane are agricultural residues. In the past, the agriculturists used to burn leaf sheath of sugarcane which caused pollution. This research aims to develop the management process of leaf sheath of sugarcane and to reduce the burning of sugarcane. In addition, to eliminate the leaf sheath of sugarcane to effectively utilize suitable for agriculture and agro-industry as well as to add value to the leaf sheath of sugarcane. This research has developed biomass energy rod from the leaf sheath of sugarcane using natural rubber as binder during drying process by microwave energy. The ingredients for forming biomass energy rod using the designed machine are sugarcane leaves of 19 %w/w, water of 57 %w/w, tapioca flour of 6 %w/w and natural latex of 19 %w/w. The biomass energy rod has diameter of 5 cm, length of 10 cm, and weighs between 150-153 g is required. The effects of heat source namely microwave drying, hot air drying and microwave-hot air drying is studied. The drying time, net heating value and residual moisture content of biomass energy rod are compared with each drying heat source. The results showed that in case study 2 using microwave energy (8 microwave sources are turned on, 250 W each) in the drying process has the lowest drying time, highest net heating value and has the lowest residual moisture content of biomass energy rod when compared to each drying heat source. The results of this research help to develop innovations in the forming and drying process of biomass energy rod using agricultural products such as leaf sheath of sugarcane.
Corrigendum to: Mislabelling may explain why some prohibited invasive aquatic plants are still being sold in Belgium
Authors: Van den Neucker Tom , Scheers Kevin
Published: April 2023

Six taxonomic errors and one relevant taxonomic change were discovered after publication of “Mislabelling may explain why some prohibited invasive aquatic plants are still being sold in Belgium” Van den Neucker T, Scheers K. 2022. Knowl Manag Aquat Ecosyst 423: 8. This corrigendum lists the changes that need to be made in the paper and in Appendices A and B. The authors state that this does not change the scientific conclusions of the paper in any way. Corrected versions of Appendices A and B are made available as supplementary material.
„Ein wesentliches Therapeutikum“ –
Arbeitstherapie in psychiatrischen Einrichtungen der DDR aus Sicht von
Zeitzeugen
Authors: Windirsch Antonia , Haack Kathleen , Grabe Hans Jörgen , Kumbier Ekkehardt
Published: April 2023

Ziel Eine Befragung von in der DDR tätigen beruflichen Akteuren
sowie ehemaliger Patienten soll helfen, die Rolle der Arbeitstherapie in
psychiatrischen Einrichtungen zu bestimmen.

Methodik Es wurden 74 Zeitzeugen befragt, die in psychiatrischen
Einrichtungen in der DDR beruflich tätig oder dort im Erwachsenenalter
behandelt worden waren. Die Interviews wurden qualitativ ausgewertet.

Ergebnisse Die Zeitzeugen beschrieben die Organisation und Ziele wie auch
Veränderungen. Der Arbeitstherapie wurde ein hoher Stellenwert
zugesprochen, da sie ein wichtiges Therapieangebot darstellte.
Gleichförmige Tätigkeiten und der Missbrauch der Arbeitskraft
unter Vernachlässigung des therapeutischen Anspruchs wurden kritisch
gesehen.

Schlussfolgerung Zeitzeugeninterviews sollten in psychiatriehistorische
Untersuchungen einbezogen werden. Für unser heutiges Verständnis
kann der Blick auf die Entwicklung der Arbeitstherapie wertvolle Erkenntnisse
liefern.
Biomechanical Comparison of Four- versus Six-Strand Transosseous Suture Repair for Patellar Tendon Rupture
Authors: Zhang Tina , Wahl Alexander , Schneider Matheus , Xu Dali , Hahn Alexander , Meredith Sean J. , Packer Jonathan D. , Leong Natalie L. , Zhang Li-Qun , Henn R. Frank , Jauregui Julio J.
Published: April 2023

Background Surgical repair is indicated for patellar tendon ruptures that result in loss of knee extensor mechanism function. However, biomechanical studies report conflicting results when comparing transosseous suture versus suture anchor repair techniques. This discrepancy may be due to inconsistencies in experimental design as these studies use various numbers of suture strands. Therefore, the main objective of this study is to compare the ultimate load of four- versus six-strand transosseous suture repair. Secondary objectives are to compare gap formation after cyclical loading and mode of failure.

Methods Six pairs of fresh-frozen cadaveric specimen were randomly allocated to either four- or six-strand transosseous suture repair. Specimen underwent preconditioning cyclical loading and then load to failure.

Results The six-strand repair had a significantly higher maximum load to failure compared with the four-strand repair (mean difference = 319.3 N [57.9%], p = 0.03). There was no significant difference in gap length after cyclical loading or at max load. There were no significant differences in mode of failure.

Conclusion Utilizing a six-stand transosseous patella tendon repair construct with one additional suture increases overall construct strength by over 50% compared with a four-strand construct.
What Can We Still Learn from Brain Autopsies in COVID-19?
Authors: Solomon Isaac H. , Singh Arjun , Folkerth Rebecca D. , Mukerji Shibani S.
Published: April 2023

Neuropathological findings have been published from ∼900 patients who died with or from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, representing less than 0.01% of the close to 6.4 million deaths reported to the World Health Organization 2 years into the coronavirus disease 2019 (COVID-19) pandemic. In this review, we extend our prior work summarizing COVID-19 neuropathology by including information on published autopsies up to June 2022, and neuropathological studies in children, COVID-19 variants, secondary brain infections, ex vivo brain imaging, and autopsies performed in countries outside of the United States or Europe. We also summarize research studies that investigate mechanisms of neuropathogenesis in nonhuman primates and other models. While a pattern of cerebrovascular pathology and microglial-predominant inflammation remains the primary COVID-19-associated neuropathological finding, there is no singular understanding of the mechanisms that underlie neurological symptoms in acute COVID-19 or the post-acute COVID-19 condition. Thus, it is paramount that we incorporate microscopic and molecular findings from brain tissue into what we know about the clinical disease so that we attain best practice guidance and direct research priorities for the study of the neurological morbidity of COVID-19.
Reformbedarf: Quo vadis, Gesundheitswesen?
Authors: Gocke Peter
Published: April 2023

Sowohl die Pandemie-Folgen als auch die durch den Krieg in der Ukraine ausgelösten wirtschaftlichen Verwerfungen stellen eine erhebliche Bedrohung für unser Gesundheitswesen dar: Erstmals zeichnen sich Klinik-Insolvenzen in einem bisher nicht beobachteteten Ausmaß ab und bringen auch größere Einheiten in Schieflage.
Hohe Energiepreise: Kostspieliger Rechenkniff
Authors: Doelfs Guntram
Published: April 2023

Viele Krankenhäuser fahren wegen der stark gestiegenen Energie- und Inflationskosten weiter hohe Millionendefizite ein, trotz des milden Winters. Im November hatte Gesundheitsminister Prof. Karl Lauterbach den Kliniken daher Hilfen in Milliardenhöhe versprochen. Angekommen ist bei den Krankenhäusern bislang aber so gut wie nichts.
Innovation: Mit Spielen zurück ins Leben
Authors: Hollmig Luisa-Maria
Published: April 2023

Therapieerfolg dank Videospielen: In der „ukb Brain Cloud 1.0“ werden Unfallpatienten mit schweren Hirnverletzungen individuell und spielerisch zugleich therapiert. Das Projekt wurde mit dem Rotthaus Klinik Award 2022 als „Digitale Innovation“ ausgezeichnet.
Digitale Helfer für die Skoliosetherapie: Therapeuten entlasten, Patienten besser betreuen
Authors: Günther Florian , Marcel Müller M.
Published: April 2023

Zwei neue digitale Anwendungen unterstützen Patientinnen und Patienten bei der konservativen Skoliosebehandlung. Die Übungen können von ihnen zu Hause allein durchgeführt werden.
Inklusive Medizin: Überforderung auf allen Seiten
Authors: Hohnstein Aileen
Published: April 2023

Die medizinische Versorgung von Menschen mit Komplexen Behinderungen ist in Krankenhäusern noch keine Selbstverständlichkeit. Personal- und Zeitmangel sowie fehlendes Wissen in der Ärzteschaft wie bei Pflegekräften erschweren einen Klinikaufenthalt. Ein inklusives Pflegemodell sowie die erste Professur für „Medizin für Menschen mit Behinderung“ sollen das ändern.
Social origin and political participation: does education compensate for or reinforce family advantages and disadvantages?
Authors: Barsegyan Vardan , Knigge Antonie , Maas Ineke
Published: April 2023

Whether educational attainment compensates for or reinforces family disadvantages in political participation is currently a debated topic. Previous research has shown a consistent relationship between social origin and political participation in Western societies: individuals originating from low-socioeconomic-status families participate in politics less than those from high-socioeconomic-status families, which violates the democratic requirement of equality of political voice. In this paper, we investigate whether secondary education compensates for or reinforces the political inequality shaped by social origin. We used a German representative sample of 1012 identical twins aged 21–25 and applied family fixed effects regression models, which allowed us to control for measured and unmeasured social and genetic confounding. We found a positive effect of educational attainment on participation, which is most likely causal. Family disadvantage resulting from low parental education is compensated for by children finishing the academic track (Gymnasium) as opposed to the lower vocational track (Hauptschule). At the same time, family advantage originating from high parental occupational status is reinforced for children completing the academic track. We found no advantage nor disadvantage, compensation nor reinforcement, related to parental income. We conclude that compensation and reinforcement of family disadvantage may remain unnoticed if components of parental SES are not distinguished.
Temperature dependent electrical and mechanical loss in gravitational wave detectors
Authors: Shapiro Maura
Published: April 2023

Low temperature gravitational wave detectors reduce mechanical loss in test masses associated with electrostatic drives.
Prediction of four Si3N4 compounds by first-principles calculations
Authors: Wu Qiaohe , Huo Zhongtang , Chen Chong , Li Xiuqing , Wang Zhou , Wang Changji , Zhang Lianjie , Gao Yufei , Xiong Mei , Pan Kunming
Published: April 2023

Four Si3N4 crystal structures were predicted using an ab initio evolutionary methodology. The mechanical and dynamic stabilities were confirmed by the density functional theory assuming zero-pressure conditions. Energetic stability calculations indicated that the structures are metastable phases at ambient pressure, but their formation is more favorable at high pressures. At zero pressure, the densities of the hp-Si3N4, cp-Si3N4, oc-Si3N4, and ti-Si3N4 phases were 3.21, 3.28, 3.70, and 3.24 g/cm3, respectively. The calculated band structures and densities of states indicated that they have semiconductive properties, with gaps ranging from 0.754 to 3.968 eV. Mechanical property calculations revealed that the hardness of the Si3N4 compounds ranged between 11.2 and 23.3 GPa, which were higher than the corresponding values for the synthesized Si3N4 phases. These four Si3N4 structures are potentially valuable candidates for the synthesis of Si3N4 compounds.
Ultra-short baseline positioning delay estimation based on signal preprocessing and fourth-order cumulant
Authors: Liu Baoheng , Da Lianglong , Zhang Xiaochuan , Jia Shuyang , Zou Sichen , Tian Deyan
Published: April 2023

To address the problem that the traditional generalized cross correlation (GCC) method in ultra-short baseline (USBL) positioning systems has a poor delay estimation accuracy in a low signal-to-noise ratio environment or complex noise background, a generalized quadratic cross correlation (GQCC) time delay estimation algorithm based on signal preprocessing and fourth-order cumulants is proposed. The noisy signal was first preprocessed using singular value decomposition and wavelet denoising. Then, the delay was calculated using an algorithm that combined the GQCC and the fourth-order cumulant. The results of the simulation and sea trial demonstrate that the proposed method is superior to the GCC method and the GQCC method and may significantly increase the positioning accuracy of the USBL system. This technique can offer a fresh technological perspective for weak signal detection and passive positioning of small targets in ocean detection.
Observation of center-type quad-domain structures in ordered BiFeO3 nanoisland arrays fabricated via mask-assisted pulsed laser deposition
Authors: Zhang Xingchen , Guo Yihang , Tian Guo , Song Zhiqing , Chen Chao , Yang Wenda , Hou Zhipeng , Chen Deyang , Fan Zhen , Zhou Guofu , Liu Jun-Ming , Gao Xingsen
Published: April 2023

Exotic topological domains in BiFeO3 nanoislands have attracted much attention regarding their potential applications in advanced electronic devices. Here, different from the earlier reported disordered distributed BiFeO3 nanoislands formed by a self-assembly method, we fabricated an ordered BiFeO3 nanoisland array by mask-assisted pulsed laser deposition on a SrTiO3 substrate, which exhibits a center-converged in-plane polarization component and a monodomain pattern along the vertical direction. Such center-type quad-domain structures exhibit high stability, maintaining their topological structures after heating to 250 °C and subsequently cooling to room temperature. Moreover, they can be switched by applying a scanning electric field and recovered by applying a heating and cooling process. Observing this topological structure in BiFeO3 nanoislands might provide a suitable platform for further exploration of its topological phase transition properties, new functions, and potential applications.
Design and numerical analysis of CIGS-based solar cell with V2O5 as the BSF layer to enhance photovoltaic performance
Authors: Rahman Md. Ferdous , Mahmud Nayeem , Alam Intekhab , Ali Md. Hasan , Moon M. M. A. , Kuddus Abdul , Toki G. F. Ishraque , Rubel M. H. K. , Al Asad Md. Abdullah , Hossain M. Khalid
Published: April 2023

Copper indium gallium selenide (CIGS)-based solar cells have exhibited greater performance than the ones utilizing cadmium telluride (CdTe) or hydrogenated amorphous silicon (a-Si: H) as the absorber. CIGS-based devices are more efficient, considering their device performance, environmentally benign nature, and reduced cost. In this article, we proposed a potential CIGS-absorber-based solar cell with an FTO/ZnSe/CIGS/V2O5/Cu heterostructure, with a V2O5 back-surface field (BSF) layer, SnO2:F (FTO) window layer, and ZnSe buffer layer. Using the solar cell capacitance simulator one-dimensional simulation software, the effects of the presence of the BSF layer, the thickness, bulk defect density, and acceptor density of the absorber layer, buffer layer thickness, interfacial defect density, device resistance, and operating temperature on the open-circuit voltage, short-circuit current, fill factor, and efficiency, as well as on the quantum efficiency and recombination and generation rate, of the device have been explored in detail. The simulation results revealed that only a 1 μm-thick-CIGS absorber layer with V2O5 BSF and ZnSe buffer layers in this structure offers an outstanding efficiency of 31.86% with a VOC of ∼0.9 V. Thus, these outcomes of the CIGS-based proposed heterostructure provide an insightful pathway for fabricating high-efficiency solar cells with performance more promising than the previously reported conventional designs.
Computational analysis of magnetic induced micropolar flow in a rectangular channel through FreeFem++
Authors: Khan M. Sabeel , Hameed Isma , Memon M. Asif , Bonyah Ebenezer
Published: April 2023

In this article, we aim to computationally analyze the magnetic induced micropolar flow in a rectangular channel using a multiphysics finite element solver, FreeFem++. In this respect, a physical model in the framework of the micropolar continuum is taken into consideration with appropriate boundary conditions. The flow is considered laminar and incompressible and moves under the application of an external magnetic field at the boundary of the flow channel. The flow governing equations of momentum, microrotation, and induction are derived, and their weak integral forms in the context of finite elements are presented. The developed finite element model is then implemented in FreeFem++ in order to compute numerical solutions to the corresponding boundary value problem. The effects of different physical parameters are studied and discussed in detail. The main findings of this investigation pertaining to different physical aspects are summarized in the conclusion. It is interesting to find that the present problem becomes unstable with specific choices of material parameters, thereby leading to an unstable solution by the direct solver. However, numerical experimentation suggests that an iterative solver based on the generalized minimum residual method can stabilize the numerical solutions. In this connection, results are shown for varying Hartmann numbers. Moreover, it is worth mentioning that FreeFEM++ provides an efficient platform to compute and analyze magnetic induced flow within the context of a higher order continuum.
Numerical analysis of hemodynamic changes and blood stagnation in the left ventricle by internal structures and torsional motion
Authors: Miyauchi Suguru , Hosoi Koichi , Tsuda Shingo , Hayase Toshiyuki , Funamoto Kenichi
Published: April 2023

It is generally believed that thrombus formation does not occur in the left ventricle (LV) because of the high speed of blood flow. However, the LV has complex internal structures such as trabeculae carneae (TC) and papillary muscles (PM) on its inner wall, which may cause blood stagnation resulting in thrombus formation. In this study, the effects of the TC, PM, and torsional motion on the hemodynamics in the LV were investigated by computational fluid dynamics (CFD) analyses. An LV model was reconstructed from magnetic resonance imaging, and the shape was modified to mimic TC and PM. Then, the CFD analyses of blood flow were performed using several different combinations of TC, PM, and torsional motion. As the results, the presence of TC decreased the time-averaged wall shear stress and increased the relative residence time (RRT) of a blood stagnation index at the apex of the LV model. The TC-induced blood stagnation was also confirmed by a transportation analysis of the passive scalar. These hemodynamic changes were attributed to the fact that TC blocked the large vortex structures generated during the diastole, thus preventing them from reaching the apex. Moreover, the PM only affected the hemodynamics in its immediate vicinity, and torsional motion caused irregular changes to the RRT level and distribution at the apex. Therefore, the complex internal structures and torsional motion of the LV could cause blood stagnation.
Electron exchange effect on surface magnetoplasmon polaritons dynamics in a graphene-plasmonic structure
Authors: Eid I. S. , Mohamed B. F. , Guo Bin
Published: April 2023

By employing a two-dimensional linearized magnetoquantum hydrodynamic model and Maxwell’s equations, the electron exchange effect on the dispersion spectrum of surface magneto-plasmon polaritons (SMPPs) is studied in a perpendicular configurated graphene-plasmonic structure where a graphene sheet is directly covered by two semi-infinite dielectrics. Besides, other influences (including the graphene electron density, the dielectric constant of the dielectric medium, and the external magnetic field) on dispersion characteristics in both classical and quantum regimes of graphene surface magneto plasmon polaritons (GSMPPs) have been investigated in the presence of an electron exchange effect. Our results show that these influences greatly affect the dynamics of GSMPPs. Also, it is found that in the presence of the electron exchange effect, the propagation speed and the dispersion spectrum shift of GSMPPs in the classical regime are largely increased more than those in the case of the quantum regime. Our findings demonstrate that the electron exchange effect has a vital function in the modulation of the dynamical behavior of SMPPs in graphene-nano optical and plasmonic devices.
Path planning of indoor mobile robot based on improved A* algorithm incorporating RRT and JPS
Authors: Mi Zengzhen , Xiao Hongjian , Huang Chonghua
Published: April 2023

Indoor mobile robots are widely used in modern industry. Traditional motion control methods for robots suffer from discontinuous path curvature, low planning efficiency, and insufficient verification of theoretical algorithms. Therefore, a motion control system for an intelligent indoor robot was designed. By optimizing the radar map detecting and positioning, path planning, and chassis motion control, the performance of the system has been improved. First, a map of the warehouse environment is established, and the number of resampling particles interval is set for the Gmapping building process to improve the efficiency of map construction. Second, an improved A* algorithm is proposed, which converts the path solution with obstacles between two points into the path solution without obstacles between multiple points based on the Rapidly expanding Random Trees and Jump Point Search algorithms and further improves the pathfinding speed and efficiency of the A* algorithm by screening the necessary expansion nodes. The Dynamic Window Approach (DWA) algorithm based on the dynamic window is used to smooth the path, and the target velocity is reasonably assigned according to the kinematic model of the robot to ensure the smooth motion of the chassis. By establishing raster map models of different sizes, the traditional and improved A* pathfinding algorithms are compared and validated. The results illustrate that the improved pathfinding algorithm reduces the computing time by 67% and increases the pathfinding speed by 47% compared with the A* algorithm. Compared with the traditional method, the speed and effect are greatly improved, and the motion control system can meet the requirements of autonomous operation of mobile robots in indoor storage.
Recombination processes in MBE grown Al0.85Ga0.15As0.56Sb0.44
Authors: Gandan Shumithira , Pinel Lucas L. G. , Morales Juan S. D. , Ng Jo Shien , Tan Chee Hing , Ochalski Tomasz
Published: April 2023

Quaternary AlGaAsSb alloys have exhibited low excess noise characteristics as gain regions in avalanche photodiodes. In this work, optical spectroscopy techniques are used to demonstrate the recombination dynamics in molecular beam epitaxy grown Al0.85Ga0.15As0.56Sb0.44 with temperature variation. Photoluminescence (PL) measurements at 8–50 K show that the bandgap varies from 1.547 to 1.527 eV. The radiative recombination processes in the alloy were found to be dictated by the complexities of antimony (Sb) incorporation during the growth. Time-resolved PL (TRPL) measurements show a change in initial carrier lifetimes of ∼3.5 µs at 8 K to ∼1 µs at 30 K. The knowledge of carrier dynamics from optical characterization methods such as PL and TRPL can be employed to contribute to shorter feedback loops for improvement of alloy fabrication in addition to enhancing growth processes.
Effects of native and H related defects on magnetic properties of SrCoO2.5 and HSrCoO2.5
Authors: Teng Gaofeng , Wang Yupu , Zhu Junyi
Published: April 2023

The tunable magnetism and reversible phase transformation between SrCoO2.5 (SCO) and HSrCoO2.5 (HSCO) have attracted vast research interest; however, the physical origin of the weakly ferromagnetism of the hydrogenated phase is still unclear. Various point defects, especially H related ones, may play important roles in the magnetic order of SCO and HSCO. In this study, we performed first-principles calculations combined with bond orbital model analysis to investigate the stabilities and magnetic effects of these defects and their complexes in both phases. We find that Hi, VO, CoSr, and Oi are relatively stable in SCO, while VH, CoSr, Hi, and Oi are relatively stable in HSCO. Additionally, these defects show significant differences of formation energy in these two phases because the charge transfer mechanisms from defects to nearby Co atoms are different. The different mechanisms also lead to different local reconstructions and crystal field splitting of the Co 3d states, affected by the interaction between Co–O bond orbital and surrounding bonding environment. Single defects of VH, Hi, and CoSr contribute significantly to the total magnetic moment of the system for HSCO or SCO. However, a ferromagnetic coupling is discovered in the two VH configurations only in HSCO, which may explain the experimental observation of the weakly ferromagnetism of HSCO.
End effects in the wake of a hydrofoil working downstream of a propeller
Authors: Posa A.
Published: April 2023

Large-eddy simulations are reported on a system consisting of a marine propeller and a downstream, semi-infinite hydrofoil, carried out on a cylindrical grid of about 3.8 × 109 points. The results are compared with those of an earlier study, considering a similar hydrofoil of infinite spanwise extent, to shed light on the influence of the end effects on the wake flow. The comparisons show good agreement between the two cases at conditions of no incidence of the hydrofoil. However, as its incidence angle grows, end effects become important. Accounting for the limited spanwise extent of the hydrofoil results in the generation of a couple of streamwise-oriented vortices from the port and starboard edges of its tip, a reduced spanwise elongation of the propeller wake, and lower turbulent stresses on the suction side of the hydrofoil, where the massive separation phenomena characterizing the infinite hydrofoil at large incidence angles are missing. In the wake of the overall system, the peak values of turbulent stresses are produced in the region of shear between the vortex shed from the pressure side edge of the tip of the hydrofoil and the tip vortices from the propeller. The latter vortices roll around the former, resulting in an intense interaction between them. In contrast, downstream of the infinite hydrofoil, the highest turbulent stresses are achieved within its wake, due to its shear with the elongated wake of the propeller.
Adaptation of QES-Fire, a dynamically coupled fast response wildfire model for heterogeneous environments
Authors: Moody Matthew J. , Stoll Rob , Bailey Brian N.
Published: April 2023

Background Modelling of fire front progression is challenging due to the large range of spatial and temporal scales involved in the interactions between the atmosphere and fire fronts. Further modelling complications arise when heterogeneous terrain and fuels are considered. Aims The aim of this study was to create a new parameterisation for wildfire-induced winds that accounts for the effects of heterogeneous terrain and fuels within the QES-Fire modelling framework – a fast-response wildfire model. Methods QES-Fire’s new turbulent plume merging model allows for distinct plumes to be merged together from fires burning in heterogeneous terrain with heterogeneous fuels. Additionally, fuel inputs from the LANDFIRE database developed for the Rothermel rate of spread (ROS) model, are translated to the Balbi ROS model. Key results The model was evaluated against the forested RxCADRE field experiment, with and without the effects of heterogeneity. Inclusion of heterogeneity reduced the relative error in burned area from 36 to 6%. Conclusions Small variations in terrain and fuel heterogeneity lead to large errors in rate and direction of fire front spread. Implications The modelled effects of terrain and fuel heterogeneity indicated the importance of capturing the complex coupled wildfire–atmospheric dynamics at the fire front.
STING-dependent interferon signatures restrict osteoclast differentiation and bone loss in mice
Authors: MacLauchlan Susan , Kushwaha Priyanka , Tai Albert , Chen Sijia , Manning Catherine , Swarnkar Gaurav , Abu-Amer Yousef , Fitzgerald Katherine A. , Sharma Shruti , Gravallese Ellen M.
Published: April 2023

Stimulator of interferon genes (STING) is a key mediator of type-I interferon (IFN-I) signaling in response to a variety of stimuli, but the contribution of STING to homeostatic processes is not fully characterized. Previous studies showed that ligand activation of STING limits osteoclast differentiation in vitro through the induction of IFNβ and IFN-I interferon-stimulated genes (ISGs). In a disease model (SAVI) driven by the V154M gain-of-function mutation in STING, fewer osteoclasts form from SAVI precursors in response to receptor activator of NF-kappaB ligand (RANKL) in an IFN-I-dependent manner. Due to the described role of STING-mediated regulation of osteoclastogenesis in activation settings, we sought to determine whether basal STING signaling contributes to bone homeostasis, an unexplored area. Using whole-body and myeloid-specific deficiency, we show that STING signaling prevents trabecular bone loss in mice over time and that myeloid-restricted STING activity is sufficient for this effect. STING-deficient osteoclast precursors differentiate with greater efficiency than wild types. RNA sequencing of wild-type and STING-deficient osteoclast precursor cells and differentiating osteoclasts reveals unique clusters of ISGs including a previously undescribed ISG set expressed in RANKL naïve precursors (tonic expression) and down-regulated during differentiation. We identify a 50 gene tonic ISG signature that is STING dependent and shapes osteoclast differentiation. From this list, we identify interferon-stimulated gene 15 (ISG15) as a tonic STING-regulated ISG that limits osteoclast formation. Thus, STING is an important upstream regulator of tonic IFN-I signatures shaping the commitment to osteoclast fates, providing evidence for a nuanced and unique role for this pathway in bone homeostasis.
A marathon to nowhere
Authors: Babić Zdravko , Vuković-Stamatović Milica , Bratić Vesna
Published: April 2023

The paper examines the accession is a race metaphor in the online news articles published in three Western Balkans’ countries (Serbia, Montenegro, and Bosnia and Hercegovina), in the context of their accession to the EU. Through the methodological lens of the conceptual metaphor theory and critical metaphor analysis, our study shows that the conceptualisation of the accession as a race might purport different, even mutually conflicted political stances, i.e. it can have a laudatory function praising those at the forefront of the “race”, while at the same time calling for patience invoking the picture of the race as a marathon, long and exhausting, demanding in both time and stamina. Without delving further into the political reasons, concerns and vested interests of the stakeholders involved, what can be said with much certainty is that both the EU and the regional officials have made some creative excuses for the excessive duration of the EU integration process for the WB’s countries, and these have been analysed in the present study. The analysis has shown that the “finish line” of the race (the accession itself), long or short, is far less important in the regional news discourse than reaching further out than your co-runners, i.e. your immediate neighbours and competitors.
Regulation and characterisation of the expansion structure of dickite layers
Authors: Dang Lianfa , Ding Mingtao , Li Ye , Su Hao , Yang Kuo , Yang Yifu , Li Fangfei , Li Hongji , Xue Bing
Published: April 2023

A dickite with an expanded layer structure was prepared by the co-calcination of the dickite-urea intercalation complex, urea, and potassium chlorate at 450°C. The expansion degree of the dickite layer could be regulated by the mass ratio (P/I) of potassium chlorate to the intercalation complex. XRD and SEM results showed that with the increase of the P/I ratio, the (002) diffraction intensity of expanded dickite gradually weakened and the degree of layer expansion gradually increased. When the P/I ratio exceeded 0.375, the expanded dickite exhibited an accordion-like porous morphology. The layer expansion of dickite exposed more internal layer surfaces, which was conducive to increasing the specific surface area, mesopore volume, and absolute ζ-potential, thus enhancing the adsorption capacity of methylene blue.
Augmenting Density Matrix Renormalization Group with Disentanglers
Authors: Qian Xiangjian , Qin Mingpu
Published: April 2023

Density matrix renormalization group (DMRG) and its extensions in the form of matrix product states are arguably the choice for the study of one-dimensional quantum systems in the last three decades. However, due to the limited entanglement encoded in the wave-function ansatz, to maintain the accuracy of DMRG with the increase of the system size in the study of two-dimensional systems, exponentially increased resources are required, which limits the applicability of DMRG to only narrow systems. We introduce a new ansatz in which DMRG is augmented with disentanglers to encode area-law-like entanglement entropy (entanglement entropy supported in the new ansatz scales as l for an l × l system). In the new method, the O(D
3) low computational cost of DMRG is kept (with an overhead of O(d
4) and d the dimension of the physical degrees of freedom). We perform benchmark calculations with this approach on the two-dimensional transverse Ising and Heisenberg models. This new ansatz extends the power of DMRG in the study of two-dimensional quantum systems.
Virtual photon approach of cathodoluminescence and ion-beam induced luminescence of solids
Authors: Costantini Jean-Marc , Ogawa Tatsuhiko , Gourier Didier
Published: April 2023

A novel analysis of cathodoluminescence (CL) and ion-beam induced luminescence (IBIL) is presented on the basis of virtual photon spectra (VPS) produced by charged particles (electrons or ions) passing by luminescent species such as defects or impurities, in wide band-gap ionic-covalent solids. A discussion is provided for irradiations in a wide range of charged particle kinetic energy by using the Weizsäcker-Williams theory. The computed VPS are found to decay rapidly as a function of virtual photon (VP) energy regardless of particle energy, for close or distant collisions. The electron-energy dependence of experimental CL spectra of sapphire (α-Al2O3) is discussed in relation to the computed VPS for the primary and secondary electrons. The experimental IBIL spectra of α-Al2O3 are also analyzed in this framework for protons and helium ions in the MeV energy range. The variations of stopping power are consistent with the variation of the number of emitted VPs. The decay of IBIL yield versus ion stopping power is discussed on the basis of the variation of the computed VPS, and ionization and excitation induced by primary ions and secondary electrons. This decay is accounted for by a decrease of the yield of low-energy secondary electrons with the subsequent VP emission.
Iteratively weighted least squares solution for universal 3D similarity transformation
Authors: Zhang Chenghua , Zhao Zhangyan , Liu Yang
Published: April 2023

The 3D similarity coordinate transformation is widely used to estimate the transformation parameters for measurement datum transformation. Accurate and reliable transformation parameters are crucial for accurate and reliable data integration. However, the accuracy of the transformation parameters can be significantly affected or even severely distorted when the observed coordinates are contaminated by gross errors. To address this problem, an advanced iteratively weighted least squares solution based on the weighted least squares is proposed. This solution utilizes the singular value decomposition method to obtain the rotation matrix and introduces a novel weight estimation approach based on Gaussian function. This approach enables the weight to be normalized and optimized iteratively. To verify the accuracy and reliability of the proposed algorithm, the root mean square errors from both true and pseudo-observed values are analyzed by simulation experiments. Furthermore, the results of simulated and empirical experiments show that the proposed algorithm can effectively reduce the influence of gross errors to obtain reliable measurement datum transformation parameters. It should be noted that the new algorithm can easily be extended to the 2D/3D affine and rigid transformation cases, such as image matching, point cloud registration, and absolute orientation of photogrammetry.
Bimetallic PdY nanosponges for enhanced oxygen reduction electrocatalysis
Authors: Wang Hongjing , Ren Hang , Liu Songliang , Deng Kai , Yu Hongjie , Xu You , Li Xiaonian , Wang Ziqiang , Wang Liang
Published: April 2023

Controlling the morphology and composition of Pd-based catalysts is the key to construct highly efficient electrocatalysts for cathodic oxygen reduction reaction (ORR). Here, rare Earth element Y-doped Pd nanosponge (PdY NSs) are prepared by one-step reduction approach using NaBH4 as reductant, which are employed for ORR under 0.1 M KOH. The PdY NSs with plentiful voids can offer a large number of active sites and improve the mass transfer for ORR. Moreover, the introduction of Y alters the electronic structure of Pd, thus promoting the dissociation and adsorption of oxygen. Therefore, the prepared PdY NSs display superior ORR activity and durability to the Pd NSs and Pd black, highlighting the introduction of rare Earth element on the enhancement of ORR performance for Pd-based catalysts.
Unconventional long range triplet proximity effect in planar YBa2Cu3O7/La0.7Sr0.3MnO3/YBa2Cu3O7 Josephson junctions
Authors: Sanchez-Manzano David , Mesoraca S , Cuellar F , Cabero M , Rodriguez-Corvillo S , Rouco V , Mompean F , Garcia-Hernandez M , Gonzalez-Calbet J M , Feuillet-Palma C , Bergeal N , Lesueur J , Leon C , Villegas Javier E , Santamaria J
Published: April 2023

The proximity effect between superconductors and ferromagnets may become long range due to the generation of triplet pairs. The recent finding of a long, one micron-range unconventional Josephson effect between YBa2Cu3O7 high Tc cuprates separated by a half metallic La0.7Sr0.3MnO3 manganite ferromagnet has uncovered a novel unconventional triplet proximity effect. In this paper, we examine the temperature dependence of the critical current in planar Josephson junctions. We find that the critical current—normal resistance product follows the predictions of traditional superconductor-normal metal-superconductor junctions, which implies that triplet pairs in a ferromagnet are transported in the diffusive limit similarly to singlet pairs in a normal metal. This result calls for theoretical studies of the new triplet Josephson effect and underlines its potential in future superconducting spintronics.
Probing the initial state of inflation: analytical structure of cosmological correlators
Authors: Ghosh Diptimoy , Harsh Singh Amartya , Ullah Farman
Published: April 2023

We study the analytic structure of in-in correlation functions in a deSitter background. The aim of this study is to probe the initial conditions for inflation through the features of correlation functions of the field fluctuations, and understand precisely how an in-in correlator responds to particles in the initial state. We emphasize that the choice of vacuua and the corresponding particle interpretation for these fluctuations is flexible, and we clarify the role of this choice at the level of calculations and their diagrammatic interpretation. We consider several possibilities aside from the standard Bunch Davies (BD) vacuum prescription for the initial state, and trace the change in pole structure as one begins adding excitations; starting from just a single particle, to highly excited states and special cases such as a coherent state. We also go beyond the pole structure of the bispectrum, and calculate the 4 point classical and quantum correlators.
We illustrate — with the example of coherent states — the subtleties in concluding a Bunch Davies initial state from the absence of physical poles in the bispectrum, which is interesting in light of some recent literature.
Initial states with a finite number of excitations are plagued with disconnected diagrams isolated in phase space, and we highlight their implications on the observation of these signals, and how the situation changes as one begins to excite more and more particles. We also comment about the implications of various initial conditions on the squeezed limit of the bispectrum.
These new pole structures are a direct consequence of mixing of positive and negative frequency modes which is a characteristic of curved spacetimes; in particular, we see in detail how particles in an initial state replicate mode mixing structures. This study aims to clarify the missing details that link quantum and classical initial conditions, and sharpen our understanding of in-in correlators in inflation.