bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bianchi IX gravitational collapse of matter inhomogeneities
Authors: Giani Leonardo , Piattella Oliver F. , Kamenshchik Alexander Yu. 
Published: March 2022

Abstract
We investigate a model of gravitational collapse of matter inhomogeneities where the latter are modelled as Bianchi type IX (BIX) spacetimes. We found that this model contains, as limiting cases, both the standard spherical collapse model and the Zeldovich solution. We study how these models are affected by small anisotropies within the BIX potential. For the spherical collapse case, we found that the model is equivalent to a closed FLRW Universe filled with matter and two perfect fluids representing the anisotropic contributions. From the linear evolution up to the turnaround, the anisotropies effectively shift the value of the FLRW spatial curvature, because the fluids have effective Equation of State (EoS) parameters w ≈ -1/3. Then we estimate the impact of such anisotropies on the number density of haloes using the Press-Schechter formalism.
If a fluid description of the anisotropies is still valid after virialization, the averaged over time EoS parameters are w ≈ 1/3. Using this and demanding hydrostatic equilibrium, we find a relation between the mass M, the average radius R and the pressure p of the virialized final structure.
When we consider within the BIX ansatz small deviations from the Zeldovich solution, our qualitative analysis suggests that the so called pancakes exhibit oscillatory behavior, as would be expected in the case of a vacuum BIX spacetime.
The method of modeling on effective modes of precision ventilation at power-stressed objects
Authors: Gubanov S M , Moiseeva K M 
Published: March 2022

Abstract
The paper presents modeling on the aerodynamic ventilation processes in the large-volume production room filled with electrical equipment, which requires special conditions of air humidity and temperature. We have developed the physical and mathematical model of the aerodynamics of the ventilation flow motion in the production room, considering the heat exchange of air with the equipment and mass exchange with the environment by filtering the air through the elements of the building structures. The paper provides the calculation results on the non-stationary displacement of the air with high humidity from a building by ventilation with dried air. We have described the technique for solving the equation system of the mathematical model, which makes it possible to reduce the calculation time by several times.
Determination of changes in the parameters of reed switches in resource-saving relay protection devices of the electrical part of power plants
Authors: Neftisov A V , Talipov O M , Andreeva O A , Kirichenko L N 
Published: March 2022

Abstract
This publication is a continuation of many years of research on the development of the basis for building a unique resource-saving relay protection, which does not use current transformers to obtain information about the primary current. The authors propose to consider the possibility of building relay protection devices with the use of reed switches as sensitive elements. However, an important issue remains the study of reed switches parameters with the passage of time and the number of actuations and returns.
Groundwater vulnerability assessment using SINTACS model and GIS: A case study in Raipur city
Authors: sahu Indrajeet , Prasad A.D. , Ahmad Ishtiyaq 
Published: March 2022

Abstract
The purpose of this study is to evaluate groundwater contamination vulnerability in the Raipur region using a Geographic Information System (GIS) based model. Researchers have worked on this method in the past, but none attempted to apply this method to the Raipur region. Various hydrogeological layers of the model i.e., water table depth, unsaturated conditions, soil media, net recharge, topographic slope, aquifer media, and hydraulic conductivity have been weighted as well as classified, integrated into the GIS environment to obtain groundwater contamination vulnerability zones (GVI). The (VI) estimated ranges between 84 to 215. Furthermore, the outcome shows that 5.42% of the region shows very low vulnerability and 14.26% of the region indicates very high vulnerability. Groundwater samples of ten locations were obtained from the delineated groundwater vulnerability zones to validate the model outcomes. The nitrate concentration was observed in the low groundwater vulnerable zone is < 15 mg/l, whereas it ranges from 15-40 mg/l in the moderate groundwater vulnerable zone and more than 40mg/l in the highly vulnerable zone of groundwater. The model approach SINTACS vulnerability index (SVI) is found to be well correlated with the nitrate concentration of the region and is appropriate for GVA of Raipur city. This model approach implemented was therefore found to be efficient for the area’s prevailing hydrogeological settings.
Quantum Chemical Computations of an Efficient Push-Pull NLO Chromophore 3-[4-Nitrophenyl Azo]- 9H- Carbazole-9-Ethanol
Authors: Balaji N. , Kannan M.R. , Sheeba Sherlin Y. , Vijayakumar T. 
Published: March 2022

Abstract
Electric-optic (EO) materials are being explored for applications ranging from fiber and satellite telecommunications, optical gyroscopes, to photonic detection of radar etc. Dipolar push-pull Organic chromophores that exhibit extended π-conjugation, in particular, show enhanced second order NLO properties. The present investigation reports the quantum chemical computations of the high efficiency push-pull NLO molecule 3-[(4-Nitrophenyl Azo)] - 9H-Carbazole-9-Ethanol (NPACE). The organic push-pull molecule is optimized in gaseous and in various solvent condition using Exchange correlation function (B3LYP/MP2). Molecular electrostatic potential, thermal properties and NBO analysis have also been performed in detail. The effective electron cloud moment in the molecule is mainly governed by the physical process termed intramolecular Charge Transfer (ICT).
Enzyme Free Detection of Glucose Using MgO Nanocubes Based Extended Gate N-channel MOSFET
Authors: Prasanna APS , Prasad Kuppuswamy Guru , Pradeep Natarajan , Jayaraman Surya Velappa , Sivalingam Yuvaraj 
Published: March 2022

Abstract
MgO nanocubes were used as a sensing electrode material for detection of glucose in the extended gate field effect transistor (EGFET) configuration. MgO nanocubes were prepared by thermal CVD approach. Morphology and elemental composition of as-prepared MgO nanocubes were obtained using the scanning electron microscope (SEM) along with EDS. The sensing electrode was prepared by coating MgO nanocubes over the copper foil by doctor blade method and it was tested with various concentrations of glucose in Phosphate Buffer Saline (PBS) buffer solution. The MgO nanocubes coated electrode showed linear response for glucose concentrations from 1.6 mM to 25.6 mM. The sensitivity was calculated as 0.12 |aA/mM.cm2.
Polymer / Nanoparticle Hybrid Membrane for Fuel Cell Application
Authors: Ashwin Sidharth N. , Mani Rahulan K. , Angeline Little Flower N. 
Published: March 2022

Abstract
The nanoparticle incorporated membranes were found to be optimistic versions of modified traditional polymeric membranes for fuel cell applications, with three main characteristics of enhanced diffusion, mechanical properties, and high resistance to thermal degradation. In Nafion membrane, Ion conductivity, which arises from the interaction between sulfone group and oxidized gas, the redox reactions involve thermal energy generation due to which water present inside the membrane evaporates thus significantly hinders the efficiency of membranes. In this present work, copper oxide and nickel tungstate nanoparticles were synthesized and nanoparticle immobilized polymer membranes were fabricated using the phase-inversion technique. The synthesized nanoparticles were characterized using Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD) to analyze its surface morphology, crystallinity and elemental composition of materials were identified using Energy Dispersive X-Ray Analysis (EDAX). The membranes are studied using FESEM for its surface morphology and surface roughness of membrane by Atomic Force Microscopy (AFM) and wettability by Contact Angle measurement.
Formation of Interfacial Reaction Products in Al-4Si-1Mg/SiC Composite
Authors: Raghu R. , Prathap M.J. , Ponpichai Pandiyan P. , Nandhakumar R. , Logeshwaran A. , Ragul T. 
Published: March 2022

Abstract
In Al/SiC composite, Al and SiC reacts and forms Al4C3 at the interface according to the reaction 4A1 + 3SiC → Al4C3+ 3Si. Hence in the present work, the Al-4Si-1Mg/SiC is fabricated through stir casting process. The fabricated composite is also ultrasonically treated prior to superheating to induce the interfacial reaction. The as cast composite and the ultrasonic treated composite are superheated at 900°C and computer aided cooling curve analysis is performed in the composite for different time to quantify the extent of interfacial reaction and to study the solidification behaviour. The Si released as a by-product can alter the composition and solidification behaviour. The salt flux reclamation technique is employed to extract the interfacial reaction products from the composite. The reclaimed powders are subjected to X-ray diffraction analysis and confirmed the presence of Al4C3 particles, which be used for grain refinement applications.
Influence of sintering temperature on structural, morphological and optical properties of nanocrystalline bismuth ferrite thin films via sol-gel processing
Authors: Deepak Sharma A. , Basantakumar Sharma H. 
Published: March 2022

Abstract
Nanocrystalline thin films of pure bismuth ferrite were synthesized by sol-gel deposition technique on the corning glass substrate. The influence of sintering temperature on microstructure, morphology, and optical parameters has been systematicallystudied. Optimization of sintering temperature for single-phase nanocrystalline bismuth ferrite fabrication was carried out and found to be at 550 °C. X-ray diffraction confirms the presenceof distortedrhombohedral perovskite structure of bismuth ferrite oriented along (hkl) plane of (101).Surface morphology and Root mean square (RMS) surface roughness of the thin films prepared were determined from the micrographs of atomic force microscopy (AFM).Several optical constants viz. bandgap energy, extinction coefficient,Urbach energy, has been determined using Ultraviolet-Visible spectroscopy of the thin films within the range 200 -800 nm. With the increase in sintering temperature, there is a decrease in the optical bandgap of the material which would be essential for the wide range of applications in thin-film solar cells along with optoelectronic devices.
Surface and subsurface investigation of Al-Mg-MoS2 composite on performing wire electrical discharge machining
Authors: S Senthil Kumar , R Sudhakara Pandian , P Pitchipoo , Narayanasamy P , Senthilkumar T S 
Published: March 2022

Abstract
Metal matrix composites (MMCs) give challenges during machining because of the reinforcements present in them as this ultimately leads to increased tool wear and a poor surface finish. Considering this, Al-Mg-MoS2 composite samples prepared using powder metallurgy process are employed under unconventional machining process like wire electrical discharge machining (WEDM), since the composites prepared to possess a higher hardness and strength compared to that of pure aluminium. The machining is done under 3 different factors operated at 3 levels, peak current (10 A, 15 A & 20 A), pulse on time (60 μs, 90 μs & 120 μs), and gap voltage (40 V, 45 V & 50 V) to analyze the material removal rate (MRR), surface roughness (SR) and overcut (OC). The surface texture of the machined samples is analyzed with scanning electron microscopy (SEM) and the recast layer so formed has also been analyzed. It is detected that the recast layer is found larger for larger surface roughness due to the higher spark energy at high-level peak current. Also, an optimal parameter of 15 A peak current, 45 V gap voltage and 90 μs pulse on time and 4% of MoS2 is determined through main effect plots for better machinability of the samples to obtain a better MRR, SR and OC. A better MRR, an improved surface finish and a reduced OC is seen in Al − 4%Mg - xMoS2 composite samples than that of pure Al and Al − 4% Mg materials.
Metal-insulator transition in monolayer MoS2 via contactless chemical doping
Authors: van Efferen Camiel , Murray Clifford , Fischer Jeison , Busse Carsten , Komsa Hannu-Pekka , Michely Thomas , Jolie Wouter 
Published: March 2022

Abstract
Much effort has been made to modify the properties of transition metal dichalcogenide layers via their environment as a route to new functionalization. However, it remains a challenge to induce large electronic changes without chemically altering the layer or compromising its two-dimensionality. Here, a non-invasive technique is used to shift the chemical potential of monolayer MoS2 through p- and n-type doping of graphene (Gr), which remains a well-decoupled 2D substrate. With the intercalation of oxygen (O) under Gr, a nearly rigid Fermi level shift of 0.45 eV in MoS2 is demonstrated, whereas the intercalation of europium (Eu) induces a metal–insulator transition in MoS2, accompanied by a giant band gap reduction of 0.67 eV. Additionally, the effect of the substrate charge on 1D states within MoS2 mirror-twin boundaries (MTBs) is explored. It is found that the 1D nature of the MTB states is not compromised, even when MoS2 is made metallic. Furthermore, with the periodicity of the 1D states dependent on substrate-induced charging and depletion, the boundaries serve as chemical potential sensors functional up to room temperature.
Correction of Bowtie filter induced scatter signals based on air scan data and object scan data
Authors: Zhang Guoqing , Wang Yang , Chen Wenhao , Li Taotao , Tian Yi 
Published: March 2022

Abstract
In a cone beam CT system, a bowtie filter brings in additional scatter signals with respect to object induced scatter signals, which can degrade image quality and sometimes result in artifacts. This work aims to improve the image quality of CT scans by analyzing the contribution of bowtie filter induced scatter signals and removing them from projection data. Air calibration is a very useful preprocessing step to eliminate the response variations of detector pixels. Bowtie filter induced scattered x-ray signals of air scans are recorded in air calibration tables and therefore considered as a part of primary signals. However, scattered X-rays behave differently in scanned objects compared to primary x-rays. The difference should be corrected to eliminate the impact of bowtie filter induced scatter signals. A kernel based correction algorithm based on air scan data, named bowtie filter scatter correction algorithm, is applied to estimate and to eliminate the bowtie filter induced scatter signals in object scans. The scatter signals of air scans can be measured with air scans or retrieved from air calibration tables of a CT system, and can be used as input of the correction algorithm to estimate the change of scatter signals caused by the scanned objects in the scan field. Based on the assumption that the scatter signals in the projection data scanned with narrow collimation can be neglected, the difference signals between narrow and broad collimations can be used to estimate bowtie filter induced scatter signals for air scans with the correction of extra-focal radiations (EFRs). The calculated bowtie filter induced scatter signals have been compared with the results of Monte Carlo simulations, and the parameters of correction algorithm have been determined by fitting the measured scatter signal curves of phantom scans with calculated curves. Projection data have been reconstructed using Filtered BackProjection (FBP) method with and without bowtie filter correction to check whether the image quality is improved. Scatter signals can be well approximated with the bowtie filter scatter correction algorithm together with an existing object scatter correction algorithm. After removing the bowtie filter induced scatter signals, the dark bands in reconstructed images in the regions near the edges of scanned objects can be mostly eliminated. The difference signals of air scan data between narrow and broad collimations can be used to estimate the bowtie filter induced scatter for air scans. The proposed bowtie filter scatter correction algorithm using air scan data can be applied to estimate and to remove most of the bowtie filter induced scatter signals in object scans.
Core outcome set for symptomatic uncomplicated gallstone disease
Authors: Innes Karen , Hudson Jemma , Banister Katie , Croal Bernard , Ramsay Craig , Ahmed Irfan , Blazeby Jane , Gillies Katie 
Published: March 2022

Abstract

Background
Heterogeneity of outcomes is a problem for assessing intervention effectiveness when considering treatments for uncomplicated symptomatic gallstone disease. The value to all stakeholders of outcomes that have been measured and reported to date is also unclear. The aim of this study was to develop a core outcome set for symptomatic uncomplicated gallstone disease.

Methods
An in person-meeting was held with patients to prioritize potentially important outcomes from a previously developed longlist of outcomes. This was followed by an online three-round Delphi survey that was conducted with healthcare professionals. The results of each consensus process were compared and combined to produce the final core outcome set.

Results
A total of 82 participants enrolled in round 1 of the Delphi survey, with a final sample of 40 participants contributing to round 3. Five patients contributed to the in-person group meeting. Following the consensus processes, 11 outcomes were considered to be core by patients and healthcare professionals, and included in the core outcome set. These were: quality of life; overall health state; overall satisfaction; overall pain; common bile duct injury; biliary leak; haemorrhage; need for endoscopic retrograde cholangiopancreatography; intra-abdominal collections; admission/readmission for problems; and reoperation.

Conclusion
A core outcome set for symptomatic uncomplicated gallstone disease has been developed with patients and healthcare professionals. Eleven outcomes across four key domains have been identified. These represent the minimum set of outcomes that should be reported in trials evaluating interventions for gallstone disease.
Neuroanatomical correlations of visuospatial processing in primary progressive aphasia
Authors: Tee Boon Lead , Watson Pereira Christa , Lukic Sladjana , Bajorek Lynn P. , Allen Isabel Elaine , Miller Zachary A. , Casaletto Kaitlin B. , Miller Bruce L. , Gorno-Tempini Maria Luisa 
Published: March 2022

Abstract
Clinical phenotyping of primary progressive aphasia has largely focused on speech and language presentations, leaving other cognitive domains under-examined. This study investigated the diagnostic utility of visuospatial profiles and examined their neural basis among the three main primary progressive aphasia variants. We studied the neuropsychological performances of 118 primary progressive aphasia participants and 30 cognitively normal controls, across 11 measures of visuospatial cognition, and investigated their neural correlates via voxel-based morphometry analysis using visuospatial composite scores derived from principal component analysis. The principal component analysis identified three main factors: visuospatial-executive, visuospatial-memory and visuomotor components. Logopenic variant primary progressive aphasia performed significantly worst across all components; nonfluent/agrammatic variant primary progressive aphasia showed deficits in the visuospatial-executive and visuomotor components compared with controls; and the semantic variant primary progressive aphasia scored significantly lower than nonfluent/agrammatic variant primary progressive aphasia and control in the visuospatial-memory component. Grey matter volumes over the right parieto-occipital cortices correlated with visuospatial-executive performance; volumetric changes in the right anterior parahippocampal gyrus and amygdala were associated with visuospatial-memory function, and visuomotor composite scores correlated significantly with the grey matter volume at the right precentral gyrus. Discriminant function analysis identified three visuospatial measures: Visual Object and Space Perception and Benson figure copy and recall test, which classified 79.7% (94/118) of primary progressive aphasia into their specific variant. This study shows that each primary progressive aphasia variant also carries a distinctive visuospatial cognitive profile that corresponds with grey matter volumetric changes and in turn can be largely represented by their performance on the visuomotor, visuospatial-memory and executive functions.
Nerve transfer with 3D-printed branch nerve conduits
Authors: Zhang Jing , Tao Jie , Cheng Hao , Liu Haofan , Wu Wenbi , Dong Yinchu , Liu Xuesong , Gou Maling , Yang Siming , Xu Jianguo 
Published: March 2022

Abstract

Background
Nerve transfer is an important clinical surgical procedure for nerve repair by the coaptation of a healthy donor nerve to an injured nerve. Usually, nerve transfer is performed in an end-to-end manner, which will lead to functional loss of the donor nerve. In this study, we aimed to evaluate the efficacy of 3D-printed branch nerve conduits in nerve transfer.

Methods
Customized branch conduits were constructed using gelatine-methacryloyl by 3D printing. The nerve conduits were characterized both in vitro and in vivo. The efficacy of 3D-printed branch nerve conduits in nerve transfer was evaluated in rats through electrophysiology testing and histological evaluation.

Results
The results obtained showed that a single nerve stump could form a complex nerve network in the 3D-printed multibranch conduit. A two-branch conduit was 3D printed for transferring the tibial nerve to the peroneal nerve in rats. In this process, the two branches were connected to the distal tibial nerve and peroneal nerve. It was found that the two nerves were successfully repaired with functional recovery.

Conclusions
It is implied that the two-branch conduit could not only repair the peroneal nerve but also preserve partial function of the donor tibial nerve. This work demonstrated that 3D-printed branch nerve conduits provide a potential method for nerve transfer.