bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization of process parameters of A-359 aluminium alloy in EPS-assisted-investment casting process using Taguchi method
Authors: Bhati Girendra , Kumar Sudhir , Kumar Ajay , Kumar Sanjeev 
Published: June 2020

AbstractThe purpose of this research is to optimize the process parameters such as pouring temperature, pouring time and the thickness of coating using Taguchi mod in expandable polystyrene assisted investment casting process. In this paper, zircon flour and mullite sand with potassium silicate binder and coarse fused-silica sand stucco are used as coating materials. Problems like cracking, breaking, bending, expanding and distending in shell are eliminated by preheating the shell and slowly rise in temperature, during foam removal process. For maximum impact strength, the optimum values of process parameters-pouring temperature, pouring time and thickness of coating layers are 750°C, 15 seconds and 5 mm respectively.
Investigation of Laser Sintered AlSi10Mg Specimens for Density and Surface Roughness
Authors: Sharma Ritesh , Kumar Sanjeev , Saha Rajeev 
Published: June 2020

Abstract
AlSi10Mg is one of the most promising alloys in SLM technology due to its low weight and competitive mechanical properties. It gives a good alternative to the conventional manufacturing systems in terms of design flexibility, cost and production time. But the parts made from laser sintering of powder are bound to have rough surface texture. The present study is focused on investigating the impact of process parameters namely laser power, scan speed, hatch spacing and orientation on density and surface roughness of the specimens sintered on selective laser melting of AlSi10Mg. To characterize the parameters, design of experiments was created using RSM and ANOVA analysis was employed to find the factors affecting the responses. The optimization was carried out in MATLAB using optimization toolbox. As per the study, hatch spacing proved to be the major contributor for influencing both density as well as surface roughness.
Prioritization of Variables Affecting the Effectiveness of Material Handling System
Authors: Kumar Surinder , Attri Rajesh 
Published: June 2020

Abstract
In today’s competitive technology environment implementation of advanced manufacturing technologies and its systems like flexible manufacturing system (FMS) has become the necessity of manufacturing organizations. Selection of appropriate material handling equipment based on their variables which affect the effectiveness of material handling system has become the necessity requirement of FMS. Keeping this fact in view, the current paper focuses on identification of different variables like speed of delivery, available space, cost and throughput rate etc. which affects the effectiveness of material handling system and prioritization of these variables using TOPSIS approach. The results of present research will aid to select an effective material handling system for enhancing the required productivity of organisations in an effective manner.
Fabrication and Characterization of hybrid aluminium-fly ash-graphite composite
Authors: Saxena Mayank , Tarique Md. , Rafi Md. , Anand Mukul , Joshi Sumit , Sharma Vipin Kumar , Singh R. C. , Chaudhary Rajiv 
Published: June 2020

Abstract
In the present paper, an aluminium metal composite with fly ash and graphite as the reinforcement were prepared using the stir casting route. The effects of reinforcements on the hardness of the Al 6061 were evaluated using a Brinell hardness tester and optical micrographs and XRD analysis was done to inspect the distribution of the reinforcements in the Al 6061 matrix. It was observed that the introduction of reinforcements in the Al matrix greatly influenced the surface hardness. There was about 32 % improvement in the hardness value. Optical micrographs also indicated the homogeneous distribution of reinforcements in the aluminium matrix.
Relationship of the electric potential inside the nano crystallite with the chemisorbed gas molecules at metal oxide semiconductor surface and its effect on gas sensor response
Authors: Kumar Anil , Kumar Ravi , Singh Rakesh , Prasad B. , Kumar Dinesh , Kumar Mukesh 
Published: June 2020

Abstract
The metal oxide semiconductors surface exhibit great gas sensing response when the size of the grains becomes much smaller i.e. in the range of debye length. In the presented study, the effect of crystal size and surface states has been studied on gas sensing properties for cylindrical shaped nanostructures of metal oxide semiconductors. To calculate the grain potential Poisson’s equation coupled with electroneutrality condition in cylindrical shaped nanostructures has been solved. The shape of the potential profile inside the nanograins has been calculated as a function of available surface states, surface temperature and occupied surface states. Eventually, the sensitivity of the gas sensor has been simulated and compared for different sizes of nanocrystals.
Design and Analysis of Cascaded H Bridge Nine-Level Inverter in Typhoon HIL
Authors: Lone Jaffar Ali , Bakhsh Farhad Ilahi 
Published: June 2020

Abstract
As the pressure on renewable energy resources like wind and solar is growing continuously because of the tremendous rise in electrical energy consumption, inverters are playing an important part. The problem with the conventional two-level inverter is that it has high harmonic pollution and low power rating. These problems limit the use of these inverters in high power applications. Therefore, the trend towards multilevel inverters is gaining more and more interest in researchers these days. In multilevel inverters, by providing a certain switching sequence, various voltage levels can be generated in a staircase manner as close as possible to a sinusoidal waveform. In this paper, Cascaded H Bridge (CHB) based nine-level inverter is designed using Typhoon Hardware-in-loop (HIL) Simulator. The Typhoon HIL Simulator is a real-time simulator that gives real-time results. The designed multilevel inverter has been analyzed for different levels. The obtained results reveal that with the increase in number of levels, the Total Harmonic Distortion (THD) of the inverter reduces.
A Novel System of Primary Oscillations for Micromechanical Gyroscope
Authors: Baranov P , Nesterenko T , Duc B B , Hao L V 
Published: June 2020

Abstract
The paper proposes a novel system of primary oscillations produced by the microelectromechanical (MEMS) gyroscope. This system is based on a synchronous detection of the current passing through the power capacitances of MEMS gyroscope. This detection method enables the excitation and stabilization of primary oscillations during two measuring cycles. The proposed system of primary oscillations also enhances the operation speed and the accuracy of frequency control, and reduces the ambient temperature effect on the stability of the scaling factor of the MEMS gyroscope.
Utilizing Wind Vibrations from Vehicular Airdrag Using Microwind Harnessing Device
Authors: Gapuz Charlyn May A. , Santiago Ronald Vincent M. 
Published: June 2020

Abstract
Windbelt has been developed to be an alternative for wind turbines to utilize wind energy, meanwhile, fast-moving vehicles in highways creates wind forces that has potential to be a source of wind energy. This study presents a windbelt prototype and evaluates the output and performance of 1, 5 and 10 connected windbelts when placed on the highway. The results reveal that for every increase in windspeed there is 0.155v and 0.485v increase in output voltage response for 5 and 10 connected windbelt respectively, indicating that the 10 connected windbelt have the highest output voltage response. This indicates that the higher the number of connected windbelts result to larger output voltage.
Correlation between Rail Vibration and Sound Radiation Using a Hammer Impact
Authors: Hou Bowen , Shao Zhuang , Zeng Qine 
Published: June 2020

Abstract
When the track structure is subject to certain excitation, the vibration characteristics and sound radiation characteristics will show certain correlation with each other. However, the study on finding the direct relationship between rail vibration and radiated sound is very limited. In this paper, the correlation between the rail vibration and radiated sound pressure under a hammer impact was investigated with a full-scale track slab. The rail acceleration, rail surface sound pressure and radiated sound pressure nearby at the rail web and rail foot were measured and analyzed in frequency domain. The transfer function, coherence function were obtained to reveal the relevance between each pair of input and output signals. Finally, by choosing rail vibration acceleration and surface sound pressure as input excitation and choosing the surface sound pressure and the sound pressure in near field as output response successively, the transfer function and the transmission loss for each pair of input and output were analyzed and compared to reveal the signal transmission in different frequency ranges.
Towards the design of a wideband reflective long period grating distributed sensor
Authors: Rana Sohel , Kandadai Nirmala , Subbaraman Harish 
Published: June 2020

Abstract
In this paper, we computationally investigate the effects of metal coating length and coating coverage on the reflected spectrum of a long period grating (LPG) over a broad bandwidth. Simulation results indicate that coating the tail end of the fiber between the LPG and the end facet of the fiber provides a reflected spectrum that mimics the LPG transmission spectrum shape over a 400 nm bandwidth. Based on single LPG simulation results, we present the design of a distributed LPG structure containing a multiple number (n) of LPGs in reflection mode for the first time. Simulation results for n = 1, 2, and 3 are presented here to demonstrate the concept of a distributed reflective LPG design. It is expected that such a sensor will open a new window for distributed sensing using reflective LPGs.
Analytical solution to DGLAP integro-differential equation via complex maps in domains of contour integrals
Authors: Álvarez Gustavo , Kondrashuk Igor 
Published: June 2020

AbstractA simple model for QCD dynamics in which the DGLAP integro-differential equation may be solved analytically has been considered in our previous papers arXiv:1611.08787[hep-ph] and arXiv:1906.07924[hep-ph]. When such a model contains only one term in the splitting function of the dominant parton distribution, then Bessel function appears to be the solution to this simplified DGLAP equation. To our knowledge, this model with only one term in the splitting function for the first time has been proposed by Blümlein in arXiv:hep-ph/9506403. In arXiv:1906.07924[hep-ph] we have shown that a dual integro-differential equation obtained from the DGLAP equation by a complex map in the plane of the Mellin moment in this model may be considered as the BFKL equation. Then, in arXiv:1906.07924 we have applied a complex diffeomorphism to obtain a standard integral from Gradshteyn and Ryzhik tables starting from the contour integral for parton distribution functions that is usually taken by calculus of residues. This standard integral from these tables appears to be the Laplace transformation of Jacobian for this complex diffeomorphism. Here we write up all the formulae behind this trick in detail and find out certain important points for further development of this strategy. We verify that the inverse Laplace transformation of the Laplace image of the Bessel function may be represented in a form of Barnes contour integral.
A relic of the past: current genetic patterns of the palaeoendemic tree Nothofagus macrocarpa were shaped by climatic oscillations in central Chile
Authors: Mathiasen Paula , Venegas-González Alejandro , Fresia Pablo , Premoli Andrea C 
Published: June 2020

AbstractBackground and AimsThe Mediterranean-type forest of central Chile is considered a ‘biodiversity hotspot’ and a relic of a wider ancient distribution produced by past climatic oscillations. Nothofagus macrocarpa, commonly known as ‘roble de Santiago’, is a threatened palaeoendemic of this forest, poorly represented in the protected area system. This tree has been repeatedly misidentified as the sister species N. obliqua, which has affected its recognition and protection. Only a few populations of N. macrocarpa remain within a matrix of intensive land use that has been affected by recent forest fires. We tested the hypothesis that current populations of N. macrocarpa are a relic state of a previously widespread range, with the aim of contributing to its identification, its biogeographical history and the design of conservation measures using genetic information.MethodsWe analysed remnant N. macrocarpa forests using nuclear (nDNA) and chloroplast DNA (cpDNA) sequences, conducted phylogenetic and phylogeographical analyses to reconstruct its biogeographical history, and assessed microsatellites [simple sequence repeats (SSRs)] to determine contemporary patters of diversity within and among all remnant populations. We also examined the degree of past, current and potential future isolation of N. macrocarpa populations using ecological niche models (ENMs).Key ResultsThe species N. macrocarpa was confirmed by nDNA sequences, as previously suggested by chromosomal analysis. Small isolated populations of N. macrocarpa exhibited moderate to high genetic diversity according to SSRs. cpDNA analysis revealed a marked past latitudinal geographical structure, whereas analysis of SSRs did not find such current structure. ENM analyses revealed local expansion–contraction of the N. macrocarpa range during warmer periods, particularly in the northern and central ranges where basal-most cpDNA haplotypes were detected, and recent expansion to the south of the distribution.ConclusionsGenetic patterns confirm that N. macrocarpa is a distinct species and suggest a marked latitudinal relic structure in at least two evolutionarily significant units, despite contemporary among-population gene flow. This information must be considered when choosing individuals (seeds and/or propagules) for restoration purposes, to avoid the admixture of divergent genetic stocks.
The impact ofSpodoptera exiguaherbivory onMeloidogyne incognita-induced root responses depends on the nematodes’ life cycle stages
Authors: Mbaluto Crispus M , Ahmad Esraa M , Fu Melody , Martínez-Medina Ainhoa , van Dam Nicole M 
Published: June 2020

AbstractInduced responses to above-ground and below-ground herbivores may interact via systemic signalling in plants. We investigated whether the impact of above-ground herbivory on root-knot nematode-induced responses depends on the nematode’s life cycle stages. Tomato plants were infected with the nematode (Meloidogyne incognita) for 5, 15 or 30 days before receiving Spodoptera exigua caterpillars above-ground. We collected root materials after 24 h of caterpillar feeding. We investigated phytohormones and α-tomatine levels, and the expression of defence and glycoalkaloid metabolism (GAME) marker genes in tomato roots. Nematode infection alone increased the endogenous root levels of jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), α-tomatine and the expression of the GLYCOALKALOID METABOLISM 1 (GAME1) gene mostly at 30 days post-nematode inoculation. Caterpillar feeding alone upregulated Lipoxygenase D and downregulated Basic-β-1-glucanase and GAME1 expression in roots. On nematode-infected plants, caterpillar feeding decreased JA levels, but it increased the expression of Leucine aminopeptidase A. The induction patterns of ABA and SA suggest that caterpillars cause cross-talk between the JA-signalling pathway and the SA and ABA pathways. Our results show that caterpillar feeding attenuated the induction of the JA pathway triggered by nematodes, mostly in the nematodes’ reproduction stage. These results generate a better understanding of the molecular and chemical mechanisms underlying frequent nematode–plant–caterpillar interactions in natural and agricultural ecosystems.
Developmental mechanisms regulating the formation of smooth muscle layers in the mouse uterus†
Authors: Nakajima Tadaaki , Sakai Naoto , Nogimura Miho , Tomooka Yasuhiro 
Published: June 2020

AbstractUterine smooth muscle cells differentiate from mesenchymal cells, and gap junctions connect the muscle cells in the myometrium. At the neonatal stage, a uterine smooth muscle layer is situated away from the epithelium when smooth muscle cells are grafted near the epithelium, suggesting that the epithelium plays an important role in differentiation, proliferation, and/or migration of smooth muscle cells. In this study, developmental mechanisms regulating the formation of the smooth muscle layers in the mouse uterus were analyzed using an in vitro culture model. Differentiation of smooth muscle cells occurs at a neonatal stage because ACTA2 gene expression was increased at the outer layer, and GJA1 was not expressed in cellular membranes of uterine smooth muscle cells by postnatal day 15. To analyze the effects of the epithelium on the differentiation of smooth muscle cells, a bulk uterine mesenchymal cell line was established from p53−/− mice at postnatal day 3 (P3US cells). Co-culture with Müllerian ductal epithelial cells (E1 cells) induced repulsive migration of ACTA2-positive cells among bulk P3US cells from E1 cells, but it had no effects on the migration of any of 100% ACTA2-positive or negative smooth muscle cell lines cloned from P3US cells. Thus, uterine epithelial cells indirectly affected the repulsive migration of smooth muscle cells via mesenchymal cells. Conditioned medium by E1 cells inhibited differentiation into smooth muscle cells of clonal cells established from P3US cells. Therefore, the uterine epithelium inhibits the differentiation of stem-like progenitor mesenchymal cells adjacent to the epithelium into smooth muscle cells.
The value of septal rebound stretch analysis for the prediction of volumetric response to cardiac resynchronization therapy
Authors: Salden Odette A E , Zweerink Alwin , Wouters Philippe , Allaart Cornelis P , Geelhoed Bastiaan , de Lange Frederik J , Maass Alexander H , Rienstra Michiel , Vernooy Kevin , Vos Marc A , Meine Mathias , Prinzen Frits W , Cramer Maarten J 
Published: June 2020

Abstract

Aims
Patient selection for cardiac resynchronization therapy (CRT) may be enhanced by evaluation of systolic myocardial stretching. We evaluate whether systolic septal rebound stretch (SRSsept) derived from speckle tracking echocardiography is a predictor of reverse remodelling after CRT and whether it holds additive predictive value over the simpler visual dyssynchrony assessment by apical rocking (ApRock).

Methods and results
The association between SRSsept and change in left ventricular end-systolic volume (ΔLVESV) at 6 months of follow-up was assessed in 200 patients. Subsequently, the additive predictive value of SRSsept over the assessment of ApRock was evaluated in patients with and without left bundle branch block (LBBB) according to strict criteria. SRSsept was independently associated with ΔLVESV (β 0.221, P = 0.002) after correction for sex, age, ischaemic cardiomyopathy, QRS morphology and duration, and ApRock. A high SRSsept (≥optimal cut-off value 2.4) also coincided with more volumetric responders (ΔLVESV ≥ −15%) than low SRSsept in the entire cohort (70.0% and 56.4%), in patients with strict LBBB (83.3% vs. 56.7%, P = 0.024), and non-LBBB (70.7% vs. 46.3%, P = 0.004). Moreover, in non-LBBB patients, SRSsept held additional predictive information over the assessment of ApRock alone since patients that showed ApRock and high SRSsept were more often volumetric responder than those with ApRock but low SRSsept (82.8% vs. 47.4%, P = 0.001).

Conclusion
SRSsept is strongly associated with CRT-induced reduction in left ventricular end-systolic volume and holds additive prognostic information over QRS morphology and ApRock. Our data suggest that CRT patient selection may be improved by assessment of SRSsept, especially in the important subgroup without strict LBBB.

Clinical trial registration
The MARC study was registered at clinicaltrials.gov: NCT01519908.
A case report of isolated severe valve stenosis in a previous tricuspid valve repair: an integrated multimodality imaging and invasive haemodynamic evaluation
Authors: Jensen Jesper Khedri , Frederiksen Christian Alcaraz , Andersen Mads Jønsson , Poulsen Steen Hvitfeldt 
Published: June 2020

Abstract

Background
Tricuspid valve (TV) stenosis is a very rare condition and the aetiology is primarily due to rheumatic disease, carcinoid disease, congenital heart disease, endocarditis, and following degeneration of biological valve prosthesis.

Case summary
We present a 45-year-old man with a rare case of symptomatic TV stenosis (TS) in a previously isolated TV repair. A meticulous multimodality diagnostic approach is presented in order to determine the severity of the TS and to evaluate the right ventricular function.

Discussion
This case report presents an integrated multimodality imaging and haemodynamic approach to evaluate and document the suspicion of development of a symptomatic significant stenosis in a previous TV repair. The initial TV repair was done without ring annuloplasty, because only the anterior leaflet was affected and bicuspidalization of the valve made it patent. In addition, minimizing the amount of implanted material was intended to minimize the risk of reinfection. The final treatment was performed as a TV replacement with insertion of a bioprosthesis.
Association of anticoagulant therapy with risk of dementia among patients with atrial fibrillation
Authors: Kim Daehoon , Yang Pil-Sung , Jang Eunsun , Yu Hee Tae , Kim Tae-Hoon , Uhm Jae-Sun , Kim Jong-Youn , Sung Jung-Hoon , Pak Hui-Nam , Lee Moon-Hyoung , Lip Gregory Y H , Joung Boyoung 
Published: June 2020

Abstract

Aims
To investigate the risk of dementia in atrial fibrillation (AF) patients treated with different oral anticoagulants (OACs).

Methods and results
This observational, population-based cohort study enrolled 53 236 dementia-free individuals with non-valvular AF who were aged ≥50 years and newly prescribed OACs from 1 January 2013 to 31 December 2016 from the Korean National Health Insurance Service database. Propensity score matching was used to compare the rates of dementia between users of non-vitamin K antagonist oral anticoagulant (NOAC) (dabigatran, rivaroxaban, and apixaban) and warfarin and to compare each individual NOAC with warfarin. Propensity score weighting analyses were also performed. In the study population (41.3% women; mean age: 70.7 years), 2194 had a diagnosis of incident dementia during a mean follow-up of 20.2 months. Relative to propensity-matched warfarin users, NOAC users tended to be at lower risk of dementia [hazard ratio (HR) 0.78, 95% confidence interval (CI) 0.69–0.90]. When comparing individual NOACs with warfarin, all the three NOACs were associated with lower dementia risk. In pairwise comparisons among NOACs, rivaroxaban was associated with decreased dementia risk, compared with dabigatran (HR 0.83, 95% CI 0.74–0.92). Supplemental propensity-weighted analyses showed consistent protective associations of NOACs with dementia relative to warfarin. The associations were consistent irrespectively of age, sex, stroke, and vascular disease and more prominent in standard dose users of NOAC.

Conclusion
In this propensity-matched and -weighted analysis using a real-world population-based cohort, use of NOACs was associated with lower dementia risk than use of warfarin among non-valvular AF patients initiating OAC treatment.
A unified theory for the circuit of atrioventricular nodal re-entrant tachycardia
Authors: Katritsis Demosthenes G 
Published: June 2020

Abstract
Atrioventricular nodal re-entrant tachycardia (AVNRT) is the most common regular tachycardia in the human, but its exact circuit remains elusive. In this article, recent evidence about the electrophysiological characteristics of AVNRT and new data on the anatomy of the atrioventricular node, are discussed. Based on this information, a novel, unified theory for the nature of the circuit of the tachycardia is presented.