bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of COVID-19 in the construction sector and its remedial measures
Authors: Biswas Ankan , Ghosh Abhinandan , Kar Adrish , Mondal Tuhin , Ghosh Buntee , Bardhan Dr.Prasanta Kumar 
Published: March 2021

Abstract
Corona virus (COVID-19) outbreaks have severely disrupted the economy, with devastating effects on global trade and it has simultaneously affected households, businesses, financial institution, industrial establishments and infrastructure companies. The economic crisis caused by the virus has hit many more organizations around the world. Similarly, construction and engineering projects around the world have been jeopardize in various way by the COVID-19 pandemic and many projects have closed. As a result, there has been a financial recession in the construction industry in almost all countries and has created unemployment. All in all, this situation has caused great concern, uncertainty and unrest in the construction industry. This paper observes in several countries and describes the global impact of the Corona virus on the construction industry. This paper also explains how it is possible to continue construction work in this situation. If construction work continues, the economic downturn will be reduced and unemployment will be reduced.
Attendance and attention monitoring - a perspective in digital pedagogy
Authors: Saha Dwaipayan , Mukherjee Indrani , Roy Jesmin , Sarkar Bikramjit , Bhattacharjee Rupak 
Published: March 2021

Abstract
Technology has played an integral role in the field of education. Its prominence and efficacy have proved to be a great boon for the people in this New Normal after the severe outbreak of COVID-19. Although the entire world is confined among the four walls, it is the technology that contributed a lot by enabling the conduction of online classes through different Learning Management Systems and multidimensional efforts of student-teacher fraternity. Earlier the Distance Learning was prevalent but was not given much importance owing to own limitations. This period of emergency has identified and highlighted the need and immense contribution of technology in digital pedagogy through online mode. In this paper we have surveyed various ways, where technology has played a gigantic role in the field of education. Various techniques for monitoring the attendance of the learners are also explored. Identifying several problems and related drawbacks of the digital transformation in the pedagogical approach, we have proposed some dynamic systems that can resolve certain issues efficiently and effectively. Solutions to mitigate the problems of attendance and to prevent the lack of attention/concentration of the students during the conduction of the online classes are presented.
Study of Adhesion Recovery phenomenon using a Multi-axle Roller-rig
Authors: Magelli Matteo 
Published: March 2021

Abstract
When a railway vehicle is running on a contaminated track, the available friction is reduced, and large creep values arise at the wheel-rail interface. However, the work of the friction forces of the leading wheelsets produces a cleaning effect on both the track and the wheels, so that the contaminant layer is partially removed, and adhesion increases on the leading as well as on the trailing wheelsets. The investigation of these adhesion recovery phenomena is the key to develop new solutions aiming to improve the vehicle dynamic behaviour in degraded adhesion conditions. Since on-field tests are usually expensive and time-consuming, roller-rigs are the typical apparatus used to simulate the vehicle dynamic behaviour in laboratory conditions. The paper describes the mechanical design of an innovative roller rig specifically designed to study adhesion recovery phenomena, consisting of four wheelsets running over the same pair of rollers. Experimental tests are performed on the test bench to obtain adhesion characteristics under dry and contaminated conditions.
Numerical modeling of selective laser melting lattice structures: A review of approaches
Authors: Alomar Z , Concli F 
Published: March 2021

Abstract
With the recent development of metal additive manufacturing processes, the fabrication of lattice structures became more feasible. Mainly, with the selective laser melting process, lattices of various topologies have been designed and manufactured with superior properties. Their excellent characteristics have drawn the attention of major leading industrial sectors. Nevertheless, their full-scale adoption is still limited, owing to the lack of a standard numerical model that can accurately represent the lattices’ mechanical and failure response. The main challenge in developing such a model is the high computational cost associated with the fine three-dimensional meshes of the struts. Besides, the need to incorporate the struts’ defects into the finite element model while also accounting for the material behavior significantly increases the complexity of the model. In this context, this paper presents a review of the numerical models explicitly developed to simulate the lattices’ behavior. The potential of modeling lattices at the macro-scale level using reduce order elements will also be discussed. Overall, the aim of this paper is first to identify the important numerical parameters needed to construct the optimum numerical setup, and second to pinpoint the gaps that can be worked upon to develop a more reliable and computationally effective model.
Experimental characterization and validation by FEM analyses of a 3D-printed support
Authors: Cosmi F , Dal Maso A 
Published: March 2021

Abstract
Devices for training of healthcare specialists are widespread applications of 3D printing. BES TEST™ is an innovative test for the diagnosis of osteoporosis and similar bone diseases, based on mechanical simulations performed on a virtual biopsy of the patient’s fingers, obtained by radiograms. Operator training is performed on a phantom hand, which is held in place by a specifically-designed support, which was 3D printed using stereolithography (SLA) with Formlabs Tough V5™ resin. Our aim is twofold: (1) perform a mechanical characterization of the resin and (2) verify that the obtained material characteristics can be used for the design of 3D-printed parts, in particular the phantom hand support. Tensile tests were performed following ISO-527. FEM analyses were carried out on the support CAD model adopting the experimentally-obtained material properties. The calculated displacements were compared with those measured experimentally on the prototype, which was manufactured using the same 3D printing and post-curing parameters as the tensile samples. FEM and experimental results were in very good agreement (error < 5.5%): this confirms that, when studying the mechanical performance of SLA 3D-printed parts, it is good practice to characterize the resin using the same printing and post-curing parameters as the final part.
Investigation of the plastic zone around the crack tip in small-scale pure Titanium specimens by means of Thermal Signal Analysis and Digital Image Correlation
Authors: Di Carolo F , Palumbo D , De Finis R , Vasco-Olmo JM , Díaz FA , Galietti U 
Published: March 2021

Abstract
The local plasticity characterizing the area around the crack tip affects the elastic strain field area due to the boundary interaction between the two zones. Its effects on the SIF and on the Paris’ Law are known, hence it must be considered in the crack growth monitoring and the fatigue limit estimation. Among the different approaches developed, those focusing their attention on the interaction between the elastic stress field and the plastic area seems to be more promising in the evaluation of the crack growth behaviour. In this work, an experimental approach was adopted to identify the plastic zone around the crack. In particular the Thermal Signal Analysis was employed and the thermal footprint was compared with shape and size of the plastic zone predicted through the application of Digital Image Correlation (DIC) in combination with two theoretical models: Westergaard’s model for the stress distribution around the crack tip and the more recent Christopher–James–Patterson (CJP) model
Experimental analysis and numerical optimization of a thermoplastic composite in crashworthiness
Authors: Raponi E , Fiumarella D 
Published: March 2021

Abstract
In this work, we present an experimental analysis and a numerical optimization study for the material parameter identification of an impact attenuator made of a brand new All-PP thermoplastic composite material subjected to an axial impact load. After an experimental characterization of the material, a Finite Element (FE) numerical model of the impact attenuator is created and simulated using the LS-DYNA explicit software. Subsequently, in order to capture the force-displacement trend of the crush experimental test, a fine-tuning of some relevant material parameters through surrogate-based optimization techniques is performed. The optimization process mainly consists of (1) defining a set of target points on the load-displacement curve where to evaluate the Mean Squared Error (MSE) between the numerical and the experimental values; (2) using a Design of Experiments technique to provide a sample set on which expensive deterministic simulations are performed; (3) constructing as many surrogate approximations as the number of target points in order to predict how the load values change over the parameters’ domain; (4) predicting an overall MSE surface that is optimized by means of a genetic algorithm in a sequential domain reduction iterative procedure. Results show a good agreement between the numerical and the experimental impact load and energy curves, and hence confirm that surrogate-based optimization is a valuable technique to refine the material parameters in the numerical simulation of composite structures.
An estimation model of suspension loads in explicit multibody simulation
Authors: Cianetti F , Garzia R , Palmieri M , Ambrogi F , Braccesi C 
Published: March 2021

Abstract
Explicit simulation is an extensively tool used by automotive designer both for car-performance analysis in standard operating condition and both in drive-simulator, whom exploits the computational ability of this codes to operate in real-time. The computational capability of these simulation tools however implies a reduced set of information available in simulation results. Regards automotive sector, with a particular focus on suspension system, the confined number of information in structural terms (states of solicitation on components and constraint) can be a strong limitation in their massive use. In this context, the objective of this activity is to propose a calculation method, as simple as accurate, that foresees to characterize the suspension by an implicit multibody model, and then using the information already available in explicit multibody model (wheel motion and external forces at the contact patch) allows estimating whichever force in all points of the suspension. The results obtained with the proposed method were compared with those outcoming from ADAMS/Car supplying in all cases, good results.
Friction dissipation in reciprocating internal combustion engines: camshaft bearings
Authors: Sordo F , Scalzo G , Lavella M 
Published: March 2021

Abstract
The increasing environmental awareness of the last decades has led to a huge tightening of the restrictions on vehicle pollutant and carbon dioxide emissions. Friction dissipation plays a strategic role as its reduction necessarily leads to a decrease in CO2 emissions. Valve timing system is responsible for a significant part of the overall friction losses and provides a relatively wide margin of improvement. This system regulates intake and exhaust flows in the combustion chamber. The camshaft allows the motion transmission between the crankshaft and the valves. The main goal of this research is the friction dissipation modeling in camshaft bearings of reciprocating internal combustion engines. The proposed model is aimed to investigate possible optimization strategies and to evaluate, with an appropriate precision to the design phase, different constructive solutions of the camshaft from the point of view of friction losses. An empiric model for the evaluation of the Stribeck curve was proposed. It allows to estimate friction coefficient explicitly through a continuous function. Then, this study showed that camshaft friction losses optimization is possible, through the careful adjustment of parameters such as number of bearings, camshaft diameter and bearings dimensions.
Laser thermography NDT for the inspection of debonding in titanium based Fibre Metal Laminates
Authors: Montinaro N , Cerniglia D , Pitarresi G 
Published: March 2021

Abstract
Fibre Metal Laminates (FMLs) describe a number of aerospace-grade layered structural materials where thin metal alloy foils are interleaved with Fibre Reinforced Polymer (FRP) plies. The evaluation of bonding integrity in multilayered primary structures is of great importance, as is generally the case with the specific performance requirements of aeronautical applications. This work describes the successful implementation of an Infrared-NDT approach to evaluate debonds in FMLs panel made of Titanium/Graphite (Ti-Gr). The proposed approach uses a flying laser heat-source, raster scanning the surface, in search of defect signatures arising on the temperature distribution profile left by the moving laser, and acquired from the component surface by an IR camera. A numerical simulation of the above NDT approach is proposed and used to investigate the mechanisms allowing to correlate defects signatures to defect features and material thermal response. The outcomes of the model are also evaluated in order to optimize the experimental setup.
Adhesive contact of randomly rough surfaces: experimental and numerical investigations
Authors: Violano G , Chateauminois A , Afferrante L 
Published: March 2021

Abstract
The contact mechanics of soft matters is strongly affected by short-range adhesive interactions, which can lead to large deformations and contact instabilities.
In this work, we present both experimental and numerical investigations of the adhesive contact between soft elastic bodies with a Greenwood and Williamson (GW)-like roughness. To investigate the coalescence of neighbour contact spots, surfaces have been designed with overlapping spherical asperities. Normal contact experiments are carried out by using a home-built device. Numerical simulations are performed with the Interacting and Coalescing Hertzian Asperities (ICHA) model, conveniently modified to take account of adhesion according to the Johnson, Kendall & Roberts (JKR) theory.
Additively manufactured Ti6Al4V lattice structures: mechanical characterization and numerical investigation
Authors: Scalet G , Biffi CA , Fiocchi J , Tuissi A , Auricchio F 
Published: March 2021

Abstract
The interest in manufacturing complex devices with integrated extra-functional properties is steadily growing for high technological application fields, such as the aerospace and biomedical ones. Among advanced methods of manufacturing, additive manufacturing allows to produce complex three-dimensional geometries, like lattice structures, which possess mechanical and functional properties unachievable by their constituent materials. The present work investigates Ti6Al4V lattice structures produced by Selective Laser Melting (SLM) through a combined experimental and numerical campaign. The effects of the relative density of the elementary cell, building direction (along horizontal and vertical building directions), and sample condition (as-built and heat treated at 850°C) on the mechanical properties of the lattice structures are investigated through tensile testing. Finite element analysis is performed to analyze the stress/strain distribution due to the different investigated effects. The results provide useful insight into the deformation/failure mechanisms, stress concentrations, and mechanical properties of the studied structures as well as into their correlation to the relative density and printing process parameters. The resulting performances of the lattice structures are compared with the ones of the bulk samples.
Numerical and experimental evaluation of the energetic release during static tensile tests on short fiber reinforced composite material
Authors: Santonocito D 
Published: March 2021

Abstract
In this work, a simple numerical model is presented in order to evaluate the energetic release of short fiber composite PA66GF35 under static tensile tests. The micro-mechanical behavior of the fiber-matrix system was taken into account, as well as the fiber distribution and orientation. Numerical simulation at macro scale level were carried out to predict the temperature evolution of the material under monotonic load. Experimental validation was performed on dog-bone specimens monitoring the surface temperature with an infrared camera. A deviation from the linearity of the thermoelastic effect has been noticed for a stress level below the yielding strength of the material. The analysis of the temperature trend evolution may be a useful aid in order to identify damage initiation within the material that would lead to failure, especially under fatigue load, even adopting a simple and rapid static tensile test.
A phenomenological model for chain transmissions efficiency
Authors: Sgamma M , Bucchi F , Frendo F 
Published: March 2021

AbstractThis work deals with the development of a simplified and time-efficient phenomenological model for chain transmissions efficiency. Firstly, a complete multibody model for a final transmission of a motorcycle is developed in MSC Adams View environment, and is properly validated in terms of efficiency with experimental tests on a real chain system. Results from multibody simulations are used to develop a new analytical model, that relates all the main operating and geometry parameters of the transmission system to the transmission efficiency with simple relations. In particular, the influence of the polygonal effect on system efficiency is investigated, finding a relationship with the angle of the sprockets pitch polygon.A new parameter, called chain tension efficiency, is introduced to model the distribution of losses within the system. A linear relationship between this parameter and the number of sprockets teeth and with the system efficiency was assumed and validated, with good results. In addition, the dependence of slack span tension from several parameters, like speed, torque and number of teeth of sprockets, is investigated. In particular, it is highly dependent on the chain peripheral speed, both for a centrifugal tension and for a further linear component of tension, which might be originated by friction between links.The presented simple model can describe the chain system dynamics with low computational effort, allowing the designer to use a smart tool to select the proper transmission parameters. Due to its computational efficiency, the model is also useful for real-time and hardware-in-the-loop simulations.
mi-IsoNet: systems-scale microRNA landscape reveals rampant isoform-mediated gain of target interaction diversity and signaling specificity
Authors: Guo Li , Li Yongsheng , Cirillo Kara M , Marick Robert A , Su Zhe , Yin Xing , Hua Xu , Mills Gordon B , Sahni Nidhi , Yi S Stephen 
Published: March 2021

AbstractMicroRNA (miRNA) is not a single sequence, but a series of multiple variants (also termed isomiRs) with sequence and expression heterogeneity. Whether and how these isoforms contribute to functional variation and complexity at the systems and network levels remain largely unknown. To explore this question systematically, we comprehensively analyzed the expression of small RNAs and their target sites to interrogate functional variations between novel isomiRs and their canonical miRNA sequences. Our analyses of the pan-cancer landscape of miRNA expression indicate that multiple isomiRs generated from the same miRNA locus often exhibit remarkable variation in their sequence, expression and function. We interrogated abundant and differentially expressed 5′ isomiRs with novel seed sequences via seed shifting and identified many potential novel targets of these 5′ isomiRs that would expand interaction capabilities between small RNAs and mRNAs, rewiring regulatory networks and increasing signaling circuit complexity. Further analyses revealed that some miRNA loci might generate diverse dominant isomiRs that often involved isomiRs with varied seeds and arm-switching, suggesting a selective advantage of multiple isomiRs in regulating gene expression. Finally, experimental validation indicated that isomiRs with shifted seed sequences could regulate novel target mRNAs and therefore contribute to regulatory network rewiring. Our analysis uncovers a widespread expansion of isomiR and mRNA interaction networks compared with those seen in canonical small RNA analysis; this expansion suggests global gene regulation network perturbations by alternative small RNA variants or isoforms. Taken together, the variations in isomiRs that occur during miRNA processing and maturation are likely to play a far more complex and plastic role in gene regulation than previously anticipated.
Characteristics Associated With Household Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Ontario, Canada: A Cohort Study
Authors: Paul Lauren A , Daneman Nick , Brown Kevin A , Johnson James , van Ingen Trevor , Joh Eugene , Wilson Sarah E , Buchan Sarah A 
Published: March 2021

Abstract

Background
Within-household transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been identified as one of the main sources of spread of coronavirus disease 2019 (COVID-19) after lockdown restrictions and self-isolation guidelines are implemented. Secondary attack rates among household contacts are estimated to be 5–10 times higher than among non-household contacts, but it is unclear which individuals are more prone to transmit infection within their households.

Methods
Using address matching, a cohort was assembled of all individuals with laboratory-confirmed COVID-19 residing in private households in Ontario, Canada. Descriptive analyses were performed to compare characteristics of cases in households that experienced secondary transmission versus those that did not. Logistic regression models were fit to determine index case characteristics and neighborhood characteristics associated with transmission.

Results
Between January and July 2020, there were 26 714 individuals with COVID-19 residing in 21 226 households. Longer testing delays (≥5 vs 0 days; odds ratio [OR], 3.02; 95% confidence interval [CI], 2.53–3.60) and male gender (OR, 1.28; 95% CI, 1.18–1.38) were associated with greater odds of household secondary transmission, while being a healthcare worker (OR, .56; 95% CI, .50–.62) was associated with lower odds of transmission. Neighborhoods with larger average family size and a higher proportion of households with multiple persons per room were also associated with greater odds of transmission.

Conclusions
It is important for individuals to get tested for SARS-CoV-2 infection as soon as symptoms appear, and to isolate away from household contacts; this is particularly important in neighborhoods with large family sizes and/or crowded households.