bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accelerating boundary analog of a Kerr black hole
Authors: Good Michael R R , Foo Joshua , Linder Eric V 
Published: March 2021

Abstract
An accelerated boundary correspondence (i.e. a flat spacetime accelerating mirror trajectory) is derived for the Kerr spacetime, with a general formula that ranges from the Schwarzschild limit (zero angular momentum) to the extreme maximal spin case (yielding asymptotic uniform acceleration). The beta Bogoliubov coefficients reveal the particle spectrum is a Planck distribution at late times with temperature cooler than a Schwarzschild black hole, due to the ‘spring constant’ analog of angular momentum. The quantum stress tensor indicates a constant emission of energy flux at late times consistent with eternal thermal equilibrium.
Total versus quantum correlations in a two-mode Gaussian state
Authors: Qars Jamal El 
Published: March 2021

Abstract
In Li and Luo (2007 Phys. Rev. A 76 032327), the inequality

(
1

/

2
)

≥


was identified as a fundamental postulate for a consistent theory of quantum versus classical correlations for arbitrary measures of total



and quantum



correlations in bipartite quantum states. Besides, Hayden et al (2006 Commun. Math. Phys.
265 95) have conjectured that, in some conditions within systems endowed with infinite-dimensional Hilbert spaces, quantum correlations may dominate not only half of total correlations but total correlations itself. Here, in a two-mode Gaussian state, quantifying



and



respectively by the quantum mutual information



G

and the entanglement of formation (EoF)



F

G

, we verify that



F
,
R

G

is always less than

(
1

/

2
)



R

G

when



G

and



F

G

are defined via the Rényi-2 entropy. While via the von Neumann entropy,



F
,
V

G

may even dominate



V

G

itself, which partly consolidates the Hayden conjecture, and partly, provides strong evidence hinting that the origin of this counterintuitive behavior should intrinsically be related to the von Neumann entropy by which the EoF



F
,
V

G

is defined, rather than related to the conceptual definition of the EoF



F

. The obtained results show that—in the special case of mixed two-mode Gaussian states—quantum entanglement can be faithfully quantified by the Gaussian Rényi-2 EoF



F
,
R

G

.
Some predictions of a validated physical model of Pt–Rh thermocouple drift above 1200 °C
Authors: Pearce Jonathan V 
Published: March 2021

AbstractA simple model was recently presented which relates the electromotive force (emf) drift rate of Pt–Rh thermoelements to the vapour pressure of Pt and Rh oxides. The model assumes that the evaporation of these oxides gives rise to a continuously changing concentration of Pt and Rh, at different rates along the length of the wires, which causes a change in the Seebeck coefficient. The model was tested by comparison with high precision measurements under comparable circumstances. By considering various thermocouples of different compositions, it was demonstrated that the calculated drift rate is proportional to the measured drift rate, which represented a validation of the model. In the current study, the model is used to make some predictions concerning the set of optimum ‘zero-drift’ thermocouple wire compositions above 1200 °C. It is shown that for a wire of Pt–Rh with more than a few %Rh, there is a corresponding wire to make a thermocouple which has nearly zero thermoelectric drift, and that this is almost independent of temperature. Remarkably, this optimum relation is found to agree very well with a previous optimisation that was based on an empirical technique. An intriguing finding is that when the measurement junction is at around 1285 °C, the drift rate is very low, regardless of wire composition; the reason for this is explained by the model. This has implications for thermocouple drift testing at temperatures close to 1285 °C, which may be unreliable if the drift is inherently low regardless of the composition of the two thermoelements, as suggested by the model. The melting point of Co–C, 1324 °C, commonly used for thermocouple drift assessment, is far enough away from 1285 °C for this effect not to be a problem.
Addressing global pandemic (COVID 19) – How much testing needed to control the disease effectively
Authors: Mazumder Neelanjan , Dutta Trina , Dutta Palash , Srimani Sneha 
Published: March 2021

Abstract
Corona virus has so far infected more than 21 million people worldwide with a mortality rate of nearly 3-4%. In some countries, it given goes up as 10%. While lockdown has so far been the only practised measure to hold the spread of the virus, still rate of infection is steadily increasing. Vaccine and effective antidotes are still to come. In this scenario, effective testing only works as an eye opener and helps in strategizing further measures. However, the testing is still a concern especially in developing economies. How much testing required, what are the effective ways to test people and its associated cost are critical considerations for the authorities.
In this paper, we are going to analyse trend of positive cases detected in various countries, requirement of testing based on population density and how effective this had been in adapting containment measures. Based on reach and cost constraints, testing at a mass level is exceedingly difficult. So, testing must happen among the most representative sample of the population and the amount of testing in a representative population has a significant role in extrapolating data well on the entire population. So, we will look at what is the optimum amount of testing required per million population by various countries (which would depend on the population and population density). However, this would still not address the exact requirement of optimum sampling frame as data to do that is not available.
COVID 19 – Tracking and Management System (CTMS)
Authors: Biswas Tamajit , Hazra Pranab , Sarkar Baishali , Monda Debdas , Kumari Deepali , Mallik Niladri 
Published: March 2021

Abstract
As concerned individuals and pursuing engineers, we are greatly affected by the adversity of the implications of the Corona Virus and thus decided to come up with a solution that aims to create a digital tracking and monitoring system so as to pacify the panic that is generated from the implications and severity of the COVID-19 virus. This digital solution system is targeted to help the masses in obtaining all the relevant and necessary information related to the scenario that would keep them well informed and updated and also give them an immediate and preliminary assistance if they develop the symptoms of the COVID-19 virus so as they can be subjected to immediate medical care and attending.
Design of miniaturized FSS structure using Optimization Technique based on Machine Learning
Authors: Ray Ranjana , Pal Moumita , Sarkar Dr. Debasree Chanda 
Published: March 2021

Abstract
This work presents the design of a miniaturized FSS structure characterized by three resonant frequencies for S and C-band applications. When an incident normalized plane wave is illuminated, the miniaturized FSS shows three rejecting bands at 2.42 GHz, 7.2 GHz, and 9 GHz simultaneously with the wide bandwidth of 2.3 GHz from 5.8 GHz to 8.1 GHz. The Frequency Selective Surface is designed by creating some rectangular slots within the square patch. The resultant slotted square patch can achieve a size reduction of 93.2%, 47.8%, and 18.98%. The measured results show great acceptance for the simulated ones. The theoretical investigation has been done by the Ansoft HFSS EM simulation tool. An experimental investigation has been performed and analytical results are achieved. A machine learning technique is implemented which also validates the experimental resonant frequency values.
Production of cheap hand sanitizer with herbal ingredients
Authors: Chakraborty A , Mukhopadhyay A , Sur A , Ghosh Dr. S 
Published: March 2021

Abstract
Novel Corona Virus has spread to 188 countries around the world which made the people infected, facing moderate respiratory illness. Currently one of the major strategies to deal with COVID-19 and reduce community transmission of infections is the frequent use of hand sanitizers. However, a large section of common mass is unable to buy them due to higher price. Therefore, an approach has been presented here to produce cheaper sanitizers with easily available herbal ingredients like Aloe Vera gel, boiled water, surgical spirit, Glycerine etc. The estimated making cost of 100 ml of sanitizer was 16 rupees. The mass production of this sanitizer can be very effective for large scale use of sanitizers by common people.
Can enhancement in tunnelling width influence the final spintronic feature of two-dimensional nanostructure of graphitic carbon nitride-(graphene)- graphitic carbon nitride?
Authors: Bhowmick Rinki , Chattopadhyaya Mausumi , Chakraborty Jit , Chakraborty Barnadip , Roy Anusweta , Neogi Biswarup , Koley Sayantanu , Sen Sabyasachi 
Published: March 2021

Abstract
Herein we present a theoretical foray on crucial role played by the graphitic tunnelling barrier in tuning spintronic feature of two-dimensional insulating graphene layer sandwiched between two ferromagnetic graphitic carbon nitride (g- C4N3) electrodes. We mainly focused on the tuning of spin filter efficiency due to the alteration in tunnelling width. 100% spin filter efficiency reported at each tunnelling width. High degree of spin filter efficiency is restored even at finite bias over a wide range of bias range -1.0 V to +1.0 V. Entire observation have been explained by analysing transmission spectrum at zero bias and a molecular level origin of the observed spintronic response of the device have been provided by analysing the Molecular Projected Self-Consistent Hamiltonian states (MPSH) and transmission pathways of the system.
Fabrication of natural polysaccharide based hydrogel with utility to entrap pollutants
Authors: Ghosh B , Bhattacharya D , Mukhopadhyay M 
Published: March 2021

Abstract
In the recent years of innovations hydrogels plays important role in various industrial applications. Hydrogels with combination of natural polymers are widely used for its biocompatibility and ecofriendly nature such as pectin and carboxymethyl cellulose (CMC). Plasticizers are utilized to enrich the physicochemical characteristics of hydrogels based on natural polymers. Polyethylene glycol 400 (PEG 400) is known to render thermostability. Whereas copper ions has wound healing properties and acts as biocide. These hydrogels due to its high porosity can have various utility to entrap small particles such as dust, pathogens and other pollutants and can act as very good face mask. Therefore the fabricated hydrogel is not only thermostable but also have high cytocompatibility, pH sensitivity, porosity and degree of swelling.
Vidyasetu - A Digital Disruption In Engineering Education System In India As An Impact Of Industry 4.0
Authors: Das P , Sarkar R , Mallik S , Majumder S , Das K , Sen S , Biswas P 
Published: March 2021

Abstract
Engineering education in India facing challenges from very past ages, but the most recent calls of Industry 4.0 may cause huge disruption for the ongoing education system. This change will not cause greater transparency or accountability of the education system, but it will reflect the role of universities, colleges on higher education, and also how people learn. Industry 4.0 described as an automation process for manufacturing in a smart way. So the time has arrived to create a new wave of the education system that only solve bookish problems but can educate the people to solve global issues. This study will discuss the problems of engineering education in India and the required change in the educational process to meet the new millennium needs of Industry 4.0.
Challenges in higher education during and after COVID-19 pandemic in India
Authors: Saha Tanusree , Das Partha Pratim , Singh Riya 
Published: March 2021

Abstract
Human Civilization has come a long way in terms of education. Starting from the ‘Pathsala’-‘Gurukul’ system to modern-day online teaching-learning, we made some massive strides. But, with arrival of Novel Corona Virus (COVID-19), an autopsy has happened to this millennium-old education system. This has pointed us to realize that, when we needed to shift the education paradigm from traditional chalk-talk method to online LMS-Blended learning technique all of a sudden within weeks, we are actually not ready. From premier institutions to the school/colleges/universities in rural area, everyone has struggled to some extent and huge amount of ground level remedial work need to be done to overcome the hurdles. Institutions need to be armed with proper infrastructure, teachers need to be trained, contents need to be developed, collaborations need to be built and the list goes on. In this paper we have discussed the challenges faced by the higher education learners and institutes in India in particular and also we have look beyond how this pandemic is going to change the educational path in future.
Effect of covid-19 on digital transformations in teaching learning methodology and its consequences in society: a review
Authors: DebarghaBanerjee  , Das Dr. Debasish , Pal Shaswatika , Paul Swarup Rudra , Debnath Akash , Reza Masud 
Published: March 2021

Abstract
Covid-19 forced all the schools, colleges and universities to suspend their physical classrooms and implemented the digital transformations into the entire education system worldwide. The structure of teaching-learning-assessment methodology becomes affected by this closure. Just a handful of universities, colleges and schools might follow teaching methods online, but private, government and low-income schools, on the other hand, have totally shut down because they do not have access to e-learning solutions. The higher education industry has been profoundly impacted by the pandemic. However, the biggest concern to everyone is how the illness impacts the pace of work. Recent graduates in India fear that the present situation will result in work offers being withdrawn from companies. To manage the crisis and develop a long-term, resilient Indian education system, a multi-stakeholder strategy is required.
Heat stress on agricultural workers exacerbates crop impacts of climate change
Authors: de Lima Cicero Z , Buzan Jonathan R , Moore Frances C , Baldos Uris Lantz C , Huber Matthew , Hertel Thomas W 
Published: March 2021

Abstract
The direct impacts of climate change on crop yields and human health are individually well-studied, but the interaction between the two have received little attention. Here we analyze the consequences of global warming for agricultural workers and the crops they cultivate using a global economic model (GTAP) with explicit treatment of the physiological impacts of heat stress on humans’ ability to work. Based on two metrics of heat stress and two labor functions, combined with a meta-analysis of crop yields, we provide an analysis of climate, impacts both on agricultural labor force, as well as on staple crop yields, thereby accounting for the interacting effect of climate change on both land and labor. Here we analyze the two sets of impacts on staple crops, while also expanding the labor impacts to highlight the potential importance on non-staple crops. We find, worldwide, labor and yield impacts within staple grains are equally important at +3 ∘C warming, relative to the 1986–2005 baseline. Furthermore, the widely overlooked labor impacts are dominant in two of the most vulnerable regions: sub-Saharan Africa and Southeast Asia. In those regions, heat stress with 3 ∘C global warming could reduce labor capacity in agriculture by 30%–50%, increasing food prices and requiring much higher levels of employment in the farm sector. The global welfare loss at this level of warming could reach $136 billion, with crop prices rising by 5%, relative to baseline.
Structural modelling of multilayer skis with an open source FEM software
Authors: Fraccaroli L , Gorla C , Concli F 
Published: March 2021

Abstract
The development process of mountaineering skis is characterized by a rapid design phase due to the continuous changes in materials, customer’s requirements and manufacturing processes. Nowadays, this type of ski is still characterized by a design process based on a basilar trials and error technique. Finite Elements Analysis (FEA) could introduce a different approach to overcome main disadvantages, such as time, of this actual design method. For this reason, the main purpose of this work is centered on the development of a reliable FE model of an existing mountaineering ski, capable to forecast the mechanical behavior of the real tool. Firstly, all mechanical properties of materials that were composing the ski were characterized. Tensile tests in the two principal directions were performed on flat dog-bones shaped specimens. Secondly, Digital Image Correlation (DIC) was combined with results obtained from tensile tests in order to approximate the four in-plane (XY) elastic properties, namely, the two elastic modules, the shear module and the Poisson ratio (Ex, Ey, Gxy, νxy). Results of the cross-correlation process were after checked with the help of numerical simulations. FEA simulations were reproducing the tensile-tests configuration. Finally, geometry, mesh and simulations-run of the ski were performed in the open source environment Code_Aster/Salome-Meca. The results of simulations of the ski were compared with the response of the real ski in three-point bending tests. Differences of 2.5%-10% with respect to the real ski were observed for the different modelling techniques.
Computational studies on cycloidal gearboxes: a systematic literature review
Authors: Maccioni L , Mastrone M N , Concli F 
Published: March 2021

Abstract
The high compactness of cycloidal gearboxes, their low backlash and their capability to withstand overloads are just some of the factors that have led the research to focus on these solutions for reducing speed. These types of gearboxes have very complex geometries, architectures and dynamics, and the contact between the various components occurs simultaneously in different areas of them. Therefore, numerical simulations can represent an essential tool for the design of these systems. The objective of this study is to understand in what and how numerical simulations can support the design of cycloidal reduction systems and make a review of the literature to understand to date, who, why and how has conducted these of studies. The reviewed contributions, collected through Scopus, are analyzed and classified according to, among others, the component modelled and analyzed, the scope of the analysis and if the analysis has been validated with experimental results. Bibliometric analyses show that the topic is of growing interest to the international scientific community but remains almost an Asian monopoly since most of the results are not shared in English. It has emerged that the study of the contact between cycloidal disk and rollers remains the most widespread study. The research showed that only a small number of analyses have been validated by experimental results.
Finite element modelling of a truck crashing into a new form of mobile vehicle blocker
Authors: Arcieri E V , Baragetti S 
Published: March 2021

Abstract
In the last years, a new form of terrorist attack has sowed panic in western countries: vehicles have been run into crowded places injuring and killing many people. The first solution to preventing the vehicle ramming attack has been the placement of concrete barriers around areas that are potential terrorist targets. The performance of these systems is questionable and the design of new, effective and good-looking protection devices is a hot topic. The authors have already presented a new certified mobile barrier, which is able to stop a 3500 kg vehicle run at 64 km/h in a few meters thank to its high deformability and the adoption of water as a filler. The water flows out and removes an appreciable amount of the impact energy. In this paper, the crashes of a 7500 kg truck running at 64 km/h against a concrete block and a single barrier designed by the authors are analysed with the help of finite element (FE) calculations in Abaqus Explicit. The water in the barrier is modelled using Smooth Particle Hydrodynamics (SPH). Due to the complexity of the truck modelling, a very simplified geometry is adopted, which is a consequence of the different versions tested. According to the results, compared to the concrete blocks, the designed barrier is overall more effective, even in a single configuration.
Validation of a multi-scale simulation strategy based on the Pointwise Strain Superposition Method
Authors: Moda M , Monelli B D , Benassi M , Palladino M 
Published: March 2021

Abstract
This paper details the experimental validation of a multi-scale simulation strategy that we developed for predicting the stresses and distortions induced by Powder Bed Fusion processes. The strategy comprises a meso-scale model, a macro-scale model, and a scaling method named Pointwise Strain Superposition. The first model evaluates the temperature, stress, and strain fields produced by a single scan line. The scaling method transfers the meso-scale results to the macro-scale model, which is then able to simulate the entire manufacturing process with a reasonable computational cost. The simulation strategy was validated by comparing its results with the stresses and distortions measured on several specimens made of selective laser melted Inconel 718. Stresses were measured through the blind hole drilling method on a cylindrical specimen printed with two different scanning strategies, while distortions were measured on a hollow cylinder and on a cantilever-shaped specimen after removing its supports. In both cases the simulation showed first- or higher-order accuracy despite the significant uncertainties regarding the input parameters and material properties. This robustness, coupled with its computational efficiency, leads us to believe that our simulation strategy could enhance the process optimization and provide a better understanding of the underlying physical phenomena along with their effects on the manufactured parts.
Influence of data input in the evaluation of Stress Intensity Factors from Thermoelastic Stress Analysis
Authors: Pitarresi Giuseppe , Cappello Riccardo , Calsi Giovanni Li , Catalanotti Giuseppe 
Published: March 2021

Abstract
Thermoelastic Stress Analysis (TSA) is applied to evaluate the Stress Intensity Factor (SIF), T-stress and J-Integral in a Single-Edge-Notched-Tension sample undergoing fatigue cycling. The Williams’ series stress formulation and a least-square fitting (LSF) procedure are used to obtain the SIF and the T-stress. The evaluation is carried out with the aim to investigate the influence of the input data in the system of equations solved with the LSF, and in particular: the number of coefficients used in the Williams’ series and the choice and position of the fitted experimental data points. Three algorithms for the determination of the crack tip position are also evaluated: a coarse grid method with pixel resolution, a refined grid method and a patternsearch method with sub-pixel resolution. In order to establish a criterion for the choice of input parameters for the LSF, the theoretical case of an infinite plate with a central crack has been analysed, for which an exact solution of the isopachics, SIF and T-stress is available. Finally, the stress separation obtained with the fully characterised Williams’ model is also used to evaluate the J-Integral by applying an Energy-Domain-Integral formulation, and the SIF retrieved from the J-Integral is compared with SIF obtained from the first coefficient of the Williams’ series.