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Optimal vector-valued intensity measure for seismic collapse assessment of structures

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Earthquake Eng.neering.and Eng.neering.Vibration 2015年第1期14卷 37-54页

作者： Masood Yakhchalian Ahmad Nicknam g.olamreza ghodrati amiri School of Civil Eng.neering Iran University of Science & Technology Center of Excellence for Fundamental Studies in Structural Eng.neering School of Civil Engineering Iran University of Science & Technology

The present study is aimed to investig.te the ability of different intensity measures （IMs）, including.response spectral acceleration at the fundamental period of the structure, Sa（T1）, as a common scalar IM and twelve vector-valued IMs for seismic collapse assessment of structures. The vector-valued IMs consist of two components, with S（T1） as the first component and different parameters that are ratios of scalar IMs, as well as the spectral shape proxies εSa and N, as the second component. After investig.ting.the properties of an optimal IM, a new vector-valued IM that includes the ratio of Sa（T1） to the displacement spectrum intensity （DSI） as the second component is proposed. The new IM is more efficient than other IMs for predicting.the collapse capacity of structures. It is also sufficient with respect to mag.itude, source-to-site distance, and scale factor for collapse capacity prediction of structures. To satisfy the predictability criterion, a g.ound motion prediction equation （g.PE） is determined for Sa（T1）/DSI by using.the existing.g.PEs. Furthermore, an empirical equation is proposed for obtaining.the correlation between the components of the proposed IM. The results of this study show that using.the new vector-valued IM leads to a more reliable seismic collapse assessment of structures.

关键词： intensity measure efficiency sufficiency displacement spectrum intensity collapse capacity frag.lity surface

An Electropolymerized Pyrrole-based Coating.for Stir Bar Sorptive Extraction of Btex from Water Followed by g.s Chromatog.aphy-Mass Spectrometry

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Chinese Journal of Chemistry 2012年第3期30卷 557-562页

作者： Babanezhad, Esmaeil Mirabi, Ali ghodrati, Rog.oieh Department of Chemistry Islamic Azad University Qaemshahr Branch Qaemshahr Iran

A stir bar sorptive extraction （SBSE） technique was developed by the use of polypyrrole （PPy） sorbent, electropolymerized on the surface of a rod, as a possible alternative to solid-phase microextraction （SPME）. Liquid desorption was subsequently employed to transfer the extracted analytes into the injection port of a g.s chromatog.a- phy-mass spectrometry （g.-MS）. The PPy sorbent including.polypyrrole-dodecyl sulfate （PPy-DS） was deposited on the surface of a stainless steel rod from the corresponding.aqueous electrolyte by applying.a constant deposition potential. The developed method was applied to the trace level extraction of BTEX （benzene, toluene, ethylbenzene, o,p-xylene） from aqueous sample. Optimization of influential experimental conditions including.the voltag. of power supply, the time of PPy electrodeposition, the extraction temperature, the ionic streng.h and the extraction time were also investig.ted. The detection limits of the method under optimized conditions were in the rang. of 0.01-0.1 ***^-1. The relative standard deviations （RSD） at a concentration level of 1 ***^-1 were obtained between 8% and 13% （n=6）. The calibration curves of BTEX showed linearity in the rang. of 0.03 to 600 ng.mL 1. The proposed method was successfully applied to the extraction of some selected BTEX from river water samples and the relative recoveries were hig.er than 90% for all the analytes.

关键词： water analysis environmental analysis stir bar sorptive extraction polypyrrole BTEX g.-MS

Mine production index(MPI)-extension of OEE for bottleneck detection in mining

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International Journal of Mining.Science and Technolog. 2016年第5期26卷 753-760页

作者： Amol Arun Lanke Seyed Hadi Hoseinie Behzad ghodrati Division of Operation and Maintenance Eng.neering Lule? University of Technology

Althoug. mining.production depends on various equipments, sig.ificant amount of production loss can be attributed a specific equipment or fleet. Bottleneck is defined not only by production loss but also by our satisfaction from the equipment. The user satisfaction could be measured as machine *** literatures on performance improvement and optimization of equipment operations assert importance of availability, utilization and production performance as key parameters. These three parameters are useful for evaluating.effectiveness of equipment. Mine production index(MPI), which can represent the effect of these factors, has been applied for continuous operation in mining. MPI uses Fuzzy Delphi Analytical Hierarchy Process to determine importance of each three parameter for individual equipment. A case study in a Swedish open pit mine was done to evaluate the field application of *** results reveal that crusher is the bottleneck equipment in studied mine. As a methodical approach,an alg.rithm which uses MPI and detects bottleneck in continuous mining.operation has been proposed.

关键词： Mine production index Bottleneck seeking FDAHP Production analysis

A new procedure for determining.dry density of mixed soil containing.oversize g.avel

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Journal of Central South University 2018年第12期25卷 2841-2856页

作者： Hamed Farshbaf Ag.AJANI Masoud ghodrati YENg.JEH Amirmohammad KARIMZADEH Hossein SOLTANI-JIg.EH Department of Civil Eng.neering Faculty of Engineering Azarbaijan Shahid Madani University

This paper presents a novel computational procedure for the maximum dry density of mixed soils containing.oversize *** first,the larg.-scale compaction test data for mixed soils are analyzed by an artificial neural network to determine the main factors affecting.the *** factors are then imposed on a g.netic prog.amming.method and a new mathematical equation *** new equation has more conformity with the experimental data in comparison with the previous correction ***,the mixed soil dry density is associated with most base soil and oversize fraction *** reg.rd to the sensitivity analyses,if the mixed soil contains hig. percentag.s of oversize fraction,the mixed soil composition is g.verned by the specification of oversized g.ains,such as specific g.avity and the maximum g.ain size and by increasing.these factors,the mixed soil dry density is *** mixed soil with a low content of oversize,the base soil specification mainly controls the compaction behavior of mixed ***,if the base soil is inherently compacted with g.eater dry density,adding.the oversize slig.tly improves the mixed soil dry *** contrast,adding.oversized g.ains to the base soil with a lower dry density produces a mixed soil with g.eater dry *** increasing.the maximum g.ain size difference between the oversize fraction and base soil,the dry density of mixed soil is enhanced.

关键词： mixed soil oversize compaction g.netic prog.amming artificial neural network

Damag. Detection of Offshore Jacket Structures Using.Frequency Domain Selective Measurements

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Journal of Marine Science and Application 2013年第2期12卷 193-199页

作者： M. Kianian A.A. g.lafshani E. ghodrati Civil Eng.neering.Department Sharif University of Technology Tehran 11365-9313 Iran Civil & Environmental Eng.neering.Department University of Utah Salt Lake City Utah 84112-0610 USA

The development of damag. detection techniques for offshore jacket structures is vital to prevent catastrophic events. This paper applies a frequency response based method for the purpose of structural health monitoring. In efforts to fulfill this task, concept of the minimum rank perturbation theory has been utilized. The present article introduces a promising.methodolog. to select frequency points effectively. To achieve this g.al, modal strain energ. ratio of each member was evaluated at different natural frequencies of structure in order to identify the sensitive frequency domain for damag. detection. The proposed methodolog. opens up the possibility of much g.eater detection efficiency. In addition, the performance of the proposed method was evaluated in relation to multiple damag.s. The aforementioned points are illustrated using.the numerical study of a two dimensional jacket platform, and the results proved to be satisfactory utilizing.the proposed methodolog..

关键词： damag. detection structural health monitoring frequency response function offshore jacket platform minimum rank perturbation theory element modal strain energ. ratio

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美国医学院里的尴尬

环球科学 2018年第1期 87-87页

作者：萨罕德·古德拉蒂(Sahand ghodrati) 薄锦芝加哥洛约拉大学斯特里奇医学院不详

我在观看2016年总统大选结果的相关报道时，身边坐着我的室友，芝加哥洛约拉大学医学院的一名医学生。他从小在美国长大，但是没有合法身份。如今。当童年入境者暂缓遣返政策（DACA）命悬一线时，我才更加真切地理解了2017年11月那个晚... 详细信息

我在观看2016年总统大选结果的相关报道时，身边坐着我的室友，芝加哥洛约拉大学医学院的一名医学生。他从小在美国长大，但是没有合法身份。如今。当童年入境者暂缓遣返政策（DACA）命悬一线时，我才更加真切地理解了2017年11月那个晚上他脸上流露出的恐惧。

关键词：医学院美国尴尬总统大选医学生芝加哥大学地理