bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partial discharge characteristics of free moving metal particles in gas insulated systems under DC and AC voltages
Authors: Sun Jixing , Wu Nana , Fan Yongzhi , Lei Dong , Yang Sile , Guo Xugang , Wang Huili , Song Sibo 
Published: May 2022

AbstractFree conductive particles in a gas‐insulated metal‐enclosed system produce partial discharges during movement, resulting in insulator flashover and insulation failures. This study focuses on the partial discharge property of free conductive particles under DC and AC voltages. The relationship between the micro‐discharge property and the intrinsic properties of the particles was obtained based on experimental tests. The results show that under DC conditions, the local discharge property varies linearly with particle size and density. The discharge probability of particles in SF6 is significantly reduced compared with that in air, while the discharge magnitude rapidly increases if the lift voltage exceeds a certain value. Under AC conditions, the partial discharge generated by the particle becomes less random, and the amplitude and phase angle of the discharge are not significantly related. As the size of the electrode decreases, the partial discharge current generated by the particles on the surface of the electrode with an uneven electric field increases significantly. This research provides a basis for the optimization of withstand voltage test method and its applications.
A risk‐based resilient distribution system planning model against extreme weather events
Authors: Zare‐Bahramabadi Majid , Ehsan Mehdi , Farzin Hossein 
Published: May 2022

AbstractDue to the accelerated climate change, it is anticipated that the number and severity of natural disasters such as hurricanes, blizzards, and floods will be increased in the coming years. In this regard, this paper presents a distribution system planning model to improve the system resilience against hurricane. A scenario‐based mathematical model is proposed to capture the random nature of weather events. Moreover, a stochastic optimization model is developed to simultaneously harden the distribution lines and place different types of distributed generation (DG) units such as microturbines (MTs), wind turbines (WTs), and photovoltaic cells (PVs). The conditional value at risk (CVaR) is used as a risk index to manage the system risk against different failure scenarios. The problem is formulated as a mixed integer linear programming (MILP) model that can be solved by various commercial solvers. Finally, to illustrate the effectiveness of the proposed model, it is implemented on the IEEE 33 bus system, and various case studies are defined. The results show the effectiveness of our mathematical model in improving the distribution system resiliency and managing the system risk.
Underwater passive manoeuvring target tracking with isogradient sound speed profile
Authors: Su Jun , Li Yaan , Ali Wasiq 
Published: May 2022

AbstractCompared with the traditional tracking problem, the underwater 3‐D passive manoeuvring target tracking faces the following challenging problems: (1) Since the signal propagation delay is varying and unknown, the relationship between the two adjacent target states is hard to describe; (2) limited by the underwater environment, it is more difficult to establish a target manoeuvring motion model; (3) the propagation speed of the underwater acoustic signal varies with the depth, and the propagation path will be curved instead of straight. Various parameters including signal propagation delay, target pitch angle and receiving frequency measured by the observer cannot be calculated as usual. In this paper, we improved a 3‐D constant turn (3D‐CT) model to match the underwater target motion. For the problems (1) and (3), this paper proposes a novel interacting multiple model underwater Gauss‐Helmert unscented Kalman filter (IMM‐UGHUKF) with isogradient sound velocity profile, which analytically describes the relationship between the state to be estimated and the passive measurement. This method augments the unknown signal emission time into the state with implicit equations, and transits the state by the Gauss–Helmert model. Simulation tests have been carried out, and the results show that IMM‐UGHUKF can significantly reduce the estimation error compared with other approaches.
A study of natural frequencies in a dynamic corona – disk system
Authors: Mastichiadis A. , Petropoulou M. , Kylafis N. D. 
Published: May 2022

Context. Black-hole X-ray binaries (BHXRBs) in the hard and hard-intermediate spectral (and temporal) states exhibit in their power spectra characteristic frequencies called type-C quasi-periodic oscillations (QPOs). Various models that can explain them with various degrees of success have been proposed, but a definitive answer is still missing.
Aims. The hot Comptonizing corona interacting with the cold accretion disk, both of which are central in understanding BHXRBs, is essentially a dynamical system. Our aim is to investigate if the radiative coupling between the two components can produce QPOs.
Methods. We write and solve the time-dependent equations that describe energy conservation in the system corona – accretion disk. We examine both constant and variable mass accretion rates. By necessity, in this first investigation we use a simple model, but it contains all the essential ingredients.
Results. For a constant mass accretion rate and certain justifiable conditions, the dynamic corona – disk system exhibits oscillations, which die out after a few cycles. The characteristic frequencies of these oscillations are similar to the ones observed in the power spectra of BHXRBs. For most parameters, the natural frequencies persist even in the case of variable accretion rates.
Conclusions. We argue that type-C QPOs in BHXRBs could, in principle, arise from the interaction of the hot Comptonizing corona with the much colder accretion disk. If this picture is correct, it has immediate implications for other systems that contain the above constituents, such as active galactic nuclei.
Sehnenpathologien im Bereich des Fußes – Inflammation
versus Degeneration: wo liegen die Unterschiede?
Authors: Arnold Ingo 
Published: May 2022

ZusammenfassungDie Ursachen für Tendopathien bzw. Tenosynovialitiden sind mannigfaltig.
Stoffwechsel und Genaktivität der Bindegewebszellen im Sehnengewebe
reagieren sehr empfindlich auf mechanische Beanspruchung und aber auch
entzündliche Reize im Hinblick auf die Integrität der
extrazellulären Matrix. Hierin unterscheiden sich entzündliche
und degenerative Sehnenerkrankungen nicht. Die verbesserten
medikamentösen Möglichkeiten einer nachhaltigen
Entzündungskontrolle erlaubt es dem Rheumaorthopäden auch
häufiger sich an den fusschirurgischen Prinzipien eines Gelenkerhaltes
orientieren zu können. Weiterhin erfordert jedoch die mit chronisch
degenerativen Prozeßen nicht vergleichbare
Entzündungsintensität einen ausreichenden Erfahrungsschatz im
peri- und intraoperativen Umganges mit den RA, SpA und PsA Patienten.
A review of the internationalization of state-owned firms and sovereign wealth funds: Governments’ nonbusiness objectives and discreet power
Authors: Cuervo-Cazurra Alvaro , Grosman Anna , Megginson William L. 
Published: May 2022

AbstractWe review and bridge the literature on the internationalization of state-owned firms and sovereign wealth funds to provide a novel understanding of how government ownership affects foreign investments in three ways. First, we explain how state-owned firms and funds behave differently from private ones because they need to balance governments’ nonbusiness objectives and firms’ business goals. This results in competing predictions on whether government ownership helps or hinders internationalization due to particular nonbusiness objectives. Second, building on the review, we provide suggestions on how to extend research topics and theories of the firm by incorporating these nonbusiness objectives in the internationalization decisions in four areas: home government’s endowments, characteristics, and attitudes; host-country expansion’s support, influence, and impact; home- and host-country relationship conflicts, mediation, and disguising; and management’s orientation, opacity, and arbitrage. Third, we capture how governments may use state-owned multinationals and sovereign wealth funds to nudge host-country governments by introducing the concept of discreet power and the use of four strategies (recognition, values, development, and supremacy) to achieve it. This helps to outline the beginning of a unified approach to how governments use their foreign investments to achieve nonbusiness goals.
Safety perceptions in university campuses: the role of environment
Authors: Huang Dengkai , Ceccato Vania , Kyttä Marketta 
Published: May 2022

AbstractThis study reports the variation in safety perceptions of university students (N = 196 university students) on university campuses in South China, focusing on the risk of crime and traffic incidents. Using a public participation geographic information system, we explore potential links between students’ perceptions and campus characteristics. We conclude that environmental cues associated with the risk of crime victimisation (e.g. lack of natural surveillance) are more often linked to poorer safety perceptions than those linked to the risk of traffic conditions. Although half of the students declare feeling safe on campus, their perception varies by individual characteristics, frequency of use, and daily experiences. Inspections of campuses environments using a door-to-door perspective are advised when safety becomes an integral part of sustainability planning of universities worldwide.
Cultural, economic, and symbolic value of the enset crop in Sebat-Bet Guraghe, Southwest Ethiopia: a qualitative study
Authors: Wondimu Habtamu , Kebede Ashenafi 
Published: May 2022

AbstractEnset, with its starch-rich corm and pseudostem, is a staple meal for over 20 million Ethiopians, although it is almost unknown outside of a small production zone in southern Ethiopia. As a result, to fill a gap, this study investigates the Gurage people of Ethiopia’s socially constructed indigenous knowledge in producing and consuming the enset plant and its economic, cultural, and symbolic representational value, which has received little attention from several authors. In achieving the study’s stated objectives, a qualitative research approach was used, allowing the researchers to investigate the lived experiences of the local people. Although secondary data sources were used to analyze the discussion in this study, primary data was predominantly used. This primary data was collected through observation, key informant interviews, casual conversations, and focus group discussions. We found that the Gurage people are somewhat different from other enset cultivating societies in enset cultivation and transplantation. According to the study’s findings, enset is a factor in wealth stratification. Despite the previous studies, we discovered that enset plays a significant role in socializing the study people in various ways. Based on the study’s findings, the researchers recommend a more in-depth study focusing on the medicinal, disease or frost tolerance, pest and pathogen incidence importance of the enset plant in Chaha Woreda.
Accurate equation of state of rhenium as pressure scale up to 130 GPa and 3200 K
Authors: Xian Yunting , Xiang Shikai , Liu Lei , Chen Junxiang , Luo Yin 
Published: May 2022

The equations of states (EOSs) of inert metals are generally used as pressure scales in a high-pressure experiment. However, the thermodynamic model and the method used to constrain the parameters of the EOSs of these metals may cause pressure deviations of up to 7% at 100 GPa and room temperature, and even higher at higher pressures and higher temperatures. In this study, we provide a new approach for obtaining accurate EOS of inert metals. First, we use a set of thermodynamic models, within the quasi-Debye framework, to describe the thermodynamics. Second, both the volume vs pressure data from the shock compression experiment and the volume vs sound velocity data from the static compression experiment are used to constrain the parameters in the EOS formula. In the fitting process, a weighted least-square method based on the uncertainty of these data is used. The calculated Grüneisen parameter shows a strong dependence not only on volume but also on temperature. The variation of the Grüneisen parameter of Re can increase by up to 7% per 103 K under the same volume, which means the previous temperature-independent approximation of the Grüneisen parameter may cause an underestimate of the pressure at high temperature. The pressure–volume–temperature EOS of Re up to 140 GPa and 3200 K is established, which can be used as a high-pressure and high-temperature pressure gauge in the future.
Electrically MHD Casson nanofluid flow and entropy exploration under the influence of the viscous dissipation, radiation, and higher-order chemical reaction
Authors: Ganesh G Raghavendra , Sridhar W , Al-Farhany Khaled , Ahmed Sameh E 
Published: May 2022

Abstract
The current study aims at studying the viscous dissipation and chemical reaction of higher-order Casson nanofluid flow and entropy exploration along with MHD and electric field influences. The PDE guiding the model is transformed into nonlinear ODE by applying adequate similarity transformations. Further, the equations are worked out using the Keller Box method. The influence of several parameters

β
,

H
a
,

E
r
,

K
r
,

N
t
,

N
b
,

S
c
,

E
c
,

Pr
,

R
d

is observed by constructing velocity, temperature, and concentration graphs using MATLAB. It is observed that entropy shows a rising tendency in the case of radiation parameter, Eckert number, decays for Casson parameter, temperature raises for radiation, Eckert parameters, and decays for Casson parameter. Velocity profiles decay for the Casson parameter. Also, local parameters skin friction, Nusselt number, and Sherwood numbers are calculated for Casson parameter, which is a function of Hartmann, number, Brownian motion parameter, thermophoresis parameter, which is a function of electric field parameter.
Unusual slow energy relaxation induced by mobile discrete breathers in one-dimensional lattices with next-nearest-neighbor coupling
Authors: Xu Bin , Zhang Jun , Zhong Wei , Xiong Chi , Xiong Daxing 
Published: May 2022

Abstract
We study the energy relaxation process in one-dimensional (1D) lattices with next-nearest-neighbor (NNN) couplings. This relaxation is produced by adding damping (absorbing conditions) to the boundary (free-end) of the lattice. Compared to the 1D lattices with on-site potentials, the properties of discrete breathers (DBs) that are spatially localized intrinsic modes are quite unusual with the NNN couplings included, i.e. these DBs are mobile, and thus they can interact with both the phonons and the boundaries of the lattice. For the interparticle interactions of harmonic and Fermi–Pasta–Ulam–Tsingou-β (FPUT-β) types, we find two crossovers of relaxation in general, i.e. a first crossover from the stretched-exponential to the regular exponential relaxation occurring in a short timescale, and a further crossover from the exponential to the power-law relaxation taking place in a long timescale. The first and second relaxations are universal, but the final power-law relaxation is strongly influenced by the properties of DBs, e.g. the scattering processes of DBs with phonons and boundaries in the FPUT-β type systems make the power-law decay relatively faster than that in the counterparts of the harmonic type systems under the same coupling. Our results present new information and insights for understanding the slow energy relaxation in cooling the lattices.
Frequency-shifted nano-particle sizing using laser self-mixing interferometry under linear current tuning
Authors: Wang Cuo , Kou Ke , Yan Jian 
Published: May 2022

Abstract
In addition to the traditional physical quantities (such as displacement, distance, velocity and vibration) detection that has been widely researched and reported, laser self-mixing interferometry (SMI) has shown great potential in nano-particle sizing during the last two decades, primarily depending on the incoherent stochastic superposition of the laser beam’s interaction with each particle in the illuminating volume. Particle diameter can be determined from the power spectra of self-mixed signals through Lorentz fitting. SMI particle sensing using laser diodes (LDs) always adopts direct current (DC) driving, so the spectrum peak occurs around zero-frequency and merely exhibits the right-hand half. Some other particle sensors using solid-state lasers (SSLs), however, prefer to employ a pair of acousto-optic modulators (AOMs) as frequency shifters, which pronouncedly increase the complexity and the cost of the whole measurement system. In this letter, linearly injected current is applied to a LD to achieve laser frequency tuning and conveniently shift the concerned Lorentz peak to any specified spectrum position, which simplifies the measurement setup and greatly avoids the influence of DC or low-frequency disturbance. The technique proposed is beneficial to developing low-cost, compact and precise SMI particle sensors or instruments.
Slot implementation on second iteration of fractal log periodic dipole antenna for UHF band application
Authors: Rosmin Muhammad Hafeez , Rahim Mohamad Kamal A , Yaziz Nur Syahirah , Iqbal Muhammad Naeem , Ayop Osman , Kamarusshahrin Muhammad Amir Haziq , Zubir Farid 
Published: May 2022

Abstract
In this paper, the design of the second iteration of Log Periodic Fractal Koch Antennas (LPFKA) with and without slot implementation is designed for Ultra High Frequency (UHF) band applications. The slot implementation is applied on each of the radiating elements to reduce the antenna’s size and to prevent the shifting of a lower frequency to a higher frequency. The antenna is operated at a frequency between 0.5 GHz and 9.0 GHz. The Computer Simulation Technology (CST) software was used to design and simulate the antenna. The performance of the antenna such as reflection coefficient, radiation pattern and gain have been analyzed. The antennas have been fabricated using an FR4 laminated board with a dielectric constant of 4.6, tangent loss of 0.019, and a thickness of 1.6mm. The results show a positive outcome, with a stable radiation pattern over the operational bandwidth and a reflection coefficient of less than -10 dB for the designed frequency.
Cylindrical Dielectric Lens Antenna for 5G Mobile Base Station
Authors: Ansarudin F , Yamada Y , Kamardin K 
Published: May 2022

Abstract
A wide range new technologies such as millimetre wave, massive MIMO technology, multi beam base station antenna are required in the fifth-generation (5G) mobile system. For multi beam base station application, a dielectric lens antenna is selected due to capabilities of achieving excellent radiation patterns in a wide angular range by applying the lens shaping method. A cylindrical structure is suitable for a lens antenna installation on the base station pole. In this paper, a cylindrical dielectric lens antenna is proposed and multi beam radiation patterns are investigated through the calculations by an electromagnetic simulator (FEKO) at the operating frequency of 28 GHz. As a result, good multi beam radiation patterns are achieved in the scanning angle from 0°to 30° with total gain reduction around 5dBi and antenna efficiency of about 95.9%.
Coupled-cluster calculation of neutron matter equation of state
Authors: Mishev Stoyan 
Published: May 2022

Abstract
We present a relation between the density and pressure of pure neutron matter derived from numerical calculations based on a truncated coupled cluster model using a simple bare nucleon-nucleon interaction in the Minnesota potential form. The obtained relationship exhibits well-known behaviour only at low densities ≲ 0.08 fm−3 and diverges from the supported by observations data equations of state at higher densities. Our results are compared with those derived from efective feld theory using realistic NN forces.
Feasibility Study of Simultaneous Measurement of Multiple Parameters from a Single Monolithic Scintillator Crystal Using the Geant4 Simulation Toolkit
Authors: Ivanov S , Toneva Zh 
Published: May 2022

Abstract
A feasibility study for the construction of a minimal multi-parameter detector module from a single monolithic CeBr3 scintillator crystal and a SiPM matrix that is capable of simultaneously measuring deposited energy, position of particle interaction and time characteristics was performed by simulation and direct measurements.
The results show that the detector module can operate successfully with characteristics that are close to the limits of the physical detector and that such minimal modules can potentially be used on micro- and nano-satellite platforms .
Streambank and floodplain geomorphic change and contribution to watershed material budgets
Authors: Noe G B , Hopkins K G , Claggett P R , Schenk E R , Metes M J , Ahmed L , Doody T R , Hupp C R 
Published: May 2022

Abstract
Stream geomorphic change is highly spatially variable but critical to landform evolution, human infrastructure, habitat, and watershed pollutant transport. However, measurements and process models of streambank erosion and floodplain deposition and resulting sediment fluxes are currently insufficient to predict these rates in all perennial streams over large regions. Here we measured long-term lateral streambank and vertical floodplain change and sediment fluxes using dendrogeomorphology in streams around the U.S. Mid-Atlantic, and then statistically modeled and extrapolated these rates to all 74 133 perennial, nontidal streams in the region using watershed- and reach-scale predictors. Measured long-term rates of streambank erosion and floodplain deposition were highly spatially variable across the landscape from the mountains to the coast. Random Forest regression identified that geomorphic change and resulting fluxes of sediment and nutrients, for both streambank and floodplain, were most influenced by urban and agricultural land use and the drainage area of the upstream watershed. Modeled rates for headwater streams were net erosional whereas downstream reaches were on average net depositional, leading to regional cumulative sediment loads from streambank erosion (−5.1 Tg yr−1) being nearly balanced by floodplain deposition (+5.3 Tg yr−1). Geomorphic changes in stream valleys had substantial influence on watershed sediment, phosphorus, carbon, and nitrogen budgets in comparison to existing predictions of upland erosion and delivery to streams and of downstream sediment loading. The unprecedented scale of these novel findings provides important insights into the balance of erosion and deposition in streams within disturbed landscapes and the importance of geomorphic change to stream water quality and carbon sequestration, and provides vital understanding for targeting management actions to restore watersheds.
Study of the additives for polymeric materials by cheminformatics methods
Authors: Bărbulescu A , Barbes L , Dumitriu C S 
Published: May 2022

Abstract
This article analyzes the structures of some antioxidants, UV stabilizers, and inhibitors utilized to improve the polymeric materials’ functionalities using Cheminformatics tools implemented in the R software. Based on their properties, the dendrograms are drawn, and the molecules are classified in clusters, utilizing hierarchical clustering and the k-means algorithm.