Calculation of Dynamic Amplification Factor for Railway Concrete and Masonry Arch Bridges Subjected to High-speed Trains

The dynamic amplification factor (DAF) is one of the most important parameters to express the dynamic behavior of bridges under moving loads. This parameter is used in bridge design codes instead of exhaustive dynamic analyses. Therefore, the DAF and the possible derived relationships can be good alternatives to dynamic analyses because of time and computational cost savings. Masonry arch bridges are complex infrastructures due to their geometry and structural behavior, and it is troublesome to prepare an accurate numerical model. To conduct dynamic analyses, due to their multiplicity, calculating the DAF of the bridges imposed by high-speed trains can lead to a rapid assessment of these old railway arch bridges. For this purpose, in the present study, the finite element models of two concrete and masonry arch bridges with small fill material heights, which are completely different in terms of geometric and mechanical characteristics, were prepared. In the next step, by performing 378 dynamic analyses based on the 27 different train models, the DAF has been computed. The results show that the calculated DAFs are in the rational range, and bogies interval, axles interval, and span length are recognized as the most important parameters in the DAF changes

Application of Fuzzy AHP and COPRAS to Solve the Supplier Selection Problems

Supply chain management (SCM) can be considered as a key component of competitive strategy to enhance organizational productivity, performance and profitability. In this paper, designed Questionnaires are sent to 5 professional experts in different departments of ABZARSAZI COMPANY in Iran. Proposed approach is based on Fuzzy Analytic Hierarchy Process (FAHP) and COPRAS (Complex Proportional Assessment) methods. The major purpose of this paper is ranking the suppliers of ABZARSAZI COMPANY by using a hybrid Fuzzy AHP and COPRAS approaches. Finally, results of this research, give an evaluation method for companies in order to help managers to identify and select the best suppliers

The effect of disciplinary background and sporting history of Premier League football players on sport legal awareness

The purpose of this study was to investigate the relationship between disciplinary background and sporting history of Premier League football players on their awareness of sports rights. In this study, descriptive-analytical method and Spearman correlation coefficient were used. Questionnaires about variables were used to identify the sample group and the main questions about players' legal awareness were used for data collection. The results showed that Pearson correlation coefficient was 0.107, Spearman correlation coefficient was 0.204 and Kendall correlation coefficient was 0.139 and significant was 0.88. There is no relationship between awareness of sports law and the history of sports in the Premier League. Based on the results of correlation coefficient and investigation of the relationship of players' disciplinary background with sport rights awareness the test statistic value is -1.73 and p-value is 0.84, so the null hypothesis is not rejected at 0.05 level and therefore between sport rights awareness and No disciplinary record found

Self-powered cardiac pacemaker by piezoelectric polymer nanogenerator implant

Self-powered biomedical implants improve the life of patients and lower the risks associated with battery replacement. Piezoelectric energy harvesters that generate electricity from the cardiac motions are among the potential candidates to be used in self-powered implants, such as cardiac pacemakers. In this context, lead-based ceramic piezoelectric nanogenerators (PNGs) were emerged, which are toxic and susceptible to fatigue crack, causing harm to the patients. Polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE)-based films were also developed as cardiac energy harvesters. Here, we show a battery-free heart pacemaker that is powered by the generated electricity of a biocompatible and flexible piezoelectric polymer-based nanogenerator (PNG) from the cardiac motions of the left ventricle. The PNG is comprised of composite nanofibers of poly(vinylidene fluoride) (PVDF) and a hybrid nanofiller made of zinc oxide (ZnO) and reduced graphene oxide (rGO). The composite nanofiber is optimized towards achieving a large power output. In vivo implanted optimized PNG can successfully harvest 0.487 μJ from every heartbeat, which is conveniently larger than the pacing threshold energy for the human heart. The successful demonstration of a self-powered pacemaker places the polymer-based PNGs among the viable candidates for self-powered biomedical implants.</p

An Integrated AHP-PROMETHEE Method for Selecting the most Suitable Ethylene Propylene Diene Termonomer

This paper considers the problem of selecting the most appropriate ethylene propylene diene monomer (EPDM), which is a polyolefin with a variety of usages in different areas. The metallocene catalyst, bis(2-phenyl indenyl) zirconium dichloride ((2-PhInd)2ZrCl2) was synthesized by a modified method and applied to the terpolymerization of ethylene, propylene, and 5-ethylidiene-2-norbornene (ENB). The methylaluminoxane (MAO) was used as a cocatalyst. It showed an appropriate activity, a high incorporation ability of the comonomers, and good performance in terpolymerization. The compounded EPDM showed good thermal stability with time. Proper criteria were chosen for the selection of the best EPDM, and a hybrid of the analytical hierarchy process (AHP) and preference ranking organization method for enrichment evaluations (PROMETHEE) was used for prioritizing 15 different synthesized EPDM species. The sensitivity and Genetic Association Interaction Analysis (GAIA) analysis were also performed. Finally, one of the polymers, which had a very high quality and moderate yield, cost, and curing time was selected

Porous graphene/poly(vinylidene fluoride) nanofibers for pressure sensing

Piezoelectric polymers have emerged as promising materials for application in pressure sensing devices in particular for wearable applications, where inorganic piezoelectric materials can face limitations due to their brittleness. One of the bottlenecks for the adaptation of piezoelectric polymers is their relatively weak piezoelectric voltage coefficient. Hence there have been numerous efforts to improve the performance of the comprising devices by making composites of poly(vinylidene fluoride) (PVDF), or through making porous PVDF films, or by nanostructuring. Here, we demonstrate the fabrication of porous nanofibers with graphene/PVDF composites and investigate the suitability of the fiber for motion sensing. The nanofibers are fabricated by electrospinning from the solution phase. Guided by an experimentally validated phase diagram for PVDF/solvent/non-solvent ternary system, porous graphene/PVDF nanofibers with different porosities and pore morphologies have been produced through solidifying the fibers in the binodal or spinodal regions of the phase diagram. It is found that only by solidifying the composite fibers in the spinodal region, graphene loading of 0.1 wt% promotes the formation of the electroactive phase substantially, and the resulting fibers exhibit enhanced piezoelectric output. It is further shown that the comprising sensors are biocompatible and show high sensitivity to body motion.</p

High variations of the thebaine concentrations in Iranian poppy (Papaver bracteatum Lindl.) from various regions in Iran

This paper aims to contribute reliable information to promote the pharmacological utilization of Papaver bracteatum by analyzing itswild population in Iran. For this purpose, 27 Iranian poppy specimens from 7 provinces of Iran were analyzed. The highest thebaine concentrations were detected in the capsules, whereas they were relatively lower in the flowering stems. Maximal concentration (more than 53 mg/g d.w.) was present in the P. bracteatum plant capsules growing in the Zanus region of Mazandaran province. Surprisingly, the thebaine concentration varies drastically excessively among the tested specimens, ranging from 5 to more than 53 mg/g d.w. Up to now, it is not known whether these drastic differences are due to clonal variations or the differences in the growth conditions, e.g., due to different stress levels of the plants. There is no doubt that the Iranian poppy represents an important alternative source for thebaine, yet, further studies and research are required to promote the farming of this auspicious pharmaceutical plant. In this context, it is of special interest to elucidate the effects of potential genotypes, the impact of the growing conditions as well as seasonal effects

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance