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Study on the Link between Lead Exposure and Hematological, Psychological, and Memorial Parameters in Automobile Repair Workers

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Health 2014年第8期6卷 712-719页

作者： Davood Fazli Ali Akbar Malekirad mahtab mirzaee Hajar Akbari Dastjerdi Sara Mostafalou Azam Karkhane Zahra Bayrami Mohammad Abdollahi Biology Department Payame Noor University Tehran Iran Environmental Toxicology and Human Health Group Tehran Iran Faculty of Biochemistry Tehran University of Medical Sciences Tehran Iran Psychology Department Arak University Arak Iran

In the surrounding environment, lead (Pb) can be released by repairing some parts of automobile engine and radiators repair works. Lead is very well-known as a neurotoxicant as some links exist between blood lead level (BLL) and neurological outcomes. This cross sectional study was performed on 35 male workers who were 23 - 40 and worked in an automobile repair shop located in an industrial part of Tehran. Clinical evidences were recorded by a questionnaire. Subjects had given their blood samples between 7 and 8 a.m. before going to work. The levels of hematological parameters were measured and the amount of lead in plasma samples was determined by graphite-furnace atomic absorption spectrophotometer. The Iranian versions of mood state and Wechsler memory questionnaire were applied in order to evaluate mood and memory impairment. The association between variables was studied using Pearson correlation coefficient. A positive correlation was seen between workers’ history on one side and, urinary frequency and restlessness on the other side. There was not any meaningful relationship between worker history, blood parameters, and mood state. A negative meaningful relationship existed between the workers’ history and visual memory. Also a positive significant relationship was observed between BLL and epigastric pain and there was a negative relationship between BLL and repeat number. There was not a significant relationship between BLL, blood parameters, and mood state as well. It was concluded that work practices in the automobile repair shop seemed to increase the body burden of lead and may pose a health risk to the workers.

关键词： Lead Mood State Memory Disorders Automobile Repair Shop

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Enhanced adaptive nonlinear extended state observer for pure feedback systems with matched and mismatched disturbances

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Control Theory and Technology 2024年第2期22卷 254-268页

作者： mahtab Delpasand Mohammad Farrokhi School of Electrical Engineering Iran University of Science and TechnologyTehran16846-13114Iran Center of Excellence for Modelling and Control of Complex Systems Iran University of Science and TechnologyTehran16846-13114Iran

In this paper, an enhanced adaptive nonlinear extended state observer (EANESO) for single-input single-output pure feedback systems in the presence of external time-varying disturbances is proposed. In this paper, a nonlinear system with matched and mismatched disturbances is considered. The conventional extended state observer (ESO) can only be applied to systems that are in the form of integral chains. Moreover, this method has limitations in the face of mismatched disturbances. In the presence of time-varying disturbances, the traditional ESOs cannot estimate the disturbances accurately. To overcome this limitation, an EANESO is proposed in this paper. The main idea is to design the nonlinear ESO (NESO) to estimate the states of the system and multiple disturbances simultaneously. The observer gains are considered time-varying and adjusted with adaptation laws to improve the estimation accuracy and overcome the peaking phenomenon. Next, the proposed controller is designed based on output feedback to eliminate the effects of multiple disturbances and stabilize the closed-loop system. Subsequently, the stability analysis of the closed-loop system and convergence of the observer error are discussed. Finally, the proposed method is applied to the inverted pendulum system. The simulated results show good performance of the proposed method as compared with a recently published scheme in the related literature.

关键词： Nonlinear extended state observer Enhanced adaptive extended state observer Adaptation law Multiple-channel disturbances Inverted pendulum system Time-varying gain

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STUDYING THE ABRASION BEHAVIOR OF RUBBERY MATERIALS WITH COMBINED DESIGN OF EXPERIMENT-ARTIFICIAL NEURAL NETWORK

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Chinese Journal of Polymer Science 2012年第4期30卷 520-529页

作者： Mehdi Shiva Hossein Atashi mahtab Hassanpourfard Research and Development Department ofKavir Tire Company.P.O.Box 518.Birjand Iran Department of Chemical Engineering Sistan and Baluchestan UniversityP.O.Box 98-164161ZahedanIran Departmen ofChemical Engineering Amirkabir University of TechnologyTehranlran

In this study, an application of artificial neural network （ANN） has been presented in modeling and studying the effect of compounding variables on abrasion behavior of rubber formulations. Three case studies were carried out in which the experiment data were collected according to classical response surface designs. Besides developing the ANN models, we developed response surface methodology （RSM） to confirm the ANN predictions. A simple relation was employed for determination of relative importance of each variable according to ANN models. It was shown through these case studies that ANN models delivered very good data fitting and their simulating curves could help the researchers to better understand the abrasion behavior.

关键词： Abrasion Feed forward neural networks Rubber compounding Central composite design.

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Practical approach to 2-thioxo-2,3-dihydroquinazolin-4(1H)-one via dithiocarbamate–anthranilic acid reaction

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Chinese Chemical Letters 2017年第1期28卷 109-112页

作者： Najmedin Azizi mahtab Edrisi Department of Green Chemistry Chemistry & Chemical Engineering Research Center of Iran P.O. Box 14335-186 Tehran Iran

A practical and straightforward protocol has been developed for the preparation of 2-thioxo-2,3-dihydroquinazolin-4（1H）-one derivatives from dithiocarbamate chemistry. The method involves the reaction of anthranilic acid derivatives（2-aminobenzoic acid, 2-aminobenzamide and isatoic anhydride）with various dithiocarbamate derivatives using ethanol as solvent. The main advantages of this protocol include practical simplicity, good to high yields, and ease of product isolation, purification and cheapness of the solvent.

关键词： Dithiocarbamate Anthranilic acid 2-Thioxo-2,3-dihydroquinazolin- 4(1H)-one 2-Aminobenzoic acid 2-Aminobenzamide lsatoic anhydride

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Intelligent Petroleum Engineering

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Engineering 2022年第11期18卷 27-32页

作者： Mohammad Ali Mirza mahtab Ghoroori Zhangxin Chen Department of Chemical and Petroleum Engineering University of CalgaryCalgaryAB T2N 1N4Canada

Data-driven approaches and artificial intelligence(AI)algorithms are promising enough to be relied on even more than physics-based methods;their main feed is data which is the fundamental element of each *** algorithms learn from data and unveil unseen patterns out of it The petroleum industry as a realm where huge volumes of data are generated every second is of great interest to this new *** the oil and gas industry is in the transition phase to oilfield digitization,there has been an increased drive to integrate data-driven modeling and machine learning(ML)algorithms in different petroleum engineering *** has been widely used in different areas of the *** extensive studies have been devoted to exploring AI applicability in various disciplines of this industry;however,lack of two main features is *** of the research is either not practical enough to be applicable in real-field challenges or limited to a specific problem and not *** must be given to data itself and the way it is classified and *** there are sheer volumes of data coming from different disciplines,they reside in departmental silos and are not accessible by *** order to derive as much insight as possible out of data,the data needs to be stored in a centralized repository from where the data can be readily consumed by different applications.

关键词： Artificial intelligence Machine learning Intelligent reservoir engineering Text mining Intelligent geoscience Intelligent drilling engineering

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Algorithms for Handoff Minimization in Wireless Networks

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Journal of Computer Science & Technology 2019年第4期34卷 887-900页

作者： Mansoor Davoodi Esmaeil Delfaraz Sajjad Ghobadi mahtab Masoori Institute for Advanced Studies in Basic Sciences Zanjan 45137-66731Iran Gran Sasso Science Institute L'Aquila 67100Italy

This study focuses on the problem of handoff minimization for a set of users moving in a wireless *** problem is analyzed by considering two cases for the user's movement under access point capacity constraints:1)all users move together,and 2)each user can have their chosen path within the *** the first case,we propose an optimal competitive ratio algorithm for the ***,in the second case,having the connectivity assumption,that is,"if a user is connected to an access point so long that the received signal strength of the access point is not less than a specified threshold,the user should continue his/her connection",we prove that no approach can reduce the number of unnecessary handoffs in an offline ***,without connectivity assumption,we present an optimal deterministic algorithm with the competitive ratio of n?for this problem under online setting,where n is the number of users and?is the maximum number of access points which cover any single point in the ***,we prove that the randomized version of the algorithm achieves an expected competitive ratio of O(log△).

关键词： competitive ratio handoff minimization offline algorithm online algorithm wireless network

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Rule of 100:An inherent limitation or performance measure in oxidative coupling of methane?

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Journal of Natural Gas Chemistry 2012年第3期21卷 308-313页

作者： Saeed Sahebdelfar Maryam Takht Ravanchi mahtab Gharibi Marzieh Hamidzadeh Catalyst Research Group Petrochemical Research and Technology CompanyNational Petrochemical CompanyNo.27Sarv AlleyShirazi-southMollasadraP.O.Box ***TehranIran

The oxidative coupling of methane over La203/CaO type-catalyst in a fixed-bed reactor is studied under a wide range of operating conditions （973〈T〈 1103 K, 55〈 Ptotal 〈220 kPa, and 3.7〈 mcat/VTp 〈50 kg.s/m^3）. A ten-step kinetic model incorporating all main products was used to predict the behavior of the system. Methane conversions and C2 selectivities were calculated by varying methane to oxygen ratios in the feed under different operating conditions which were also compared with the rule of 100. The results show that deviation from this rule depends on the operating conditions. Within the range studied, an increase in pressure, temperature and contact time results in smaller deviation from the rule. This rule is best approximated when the catalyst operates near its optimal performance. For negative deviations, common to the most catalysts, it is found that the optimal performance should occur at methane conversion levels lower than 50%. A plot of selectivity versus conversion for high-yield reported performance data of a large variety of catalysts shows that data points concentrated roughly in 20%-50% methane conversion region, confirming the generality and prediction of modeling.

关键词： oxidative coupling of methane (OCM) La203/CaO catalyst rule of 100 methane conversion C2 yield

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Omeprazole-based triple therapy with low-versus high-dose of clarithromycin plus amoxicillin for H pylori eradication in Iranian population

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World Journal of Gastroenterology 2007年第6期13卷 930-933页

作者： Ali Asghar Keshavarz Homayoon Bashiri mahtab Rahbar Department of Gastroenterology and Hepatology Emam Reza Hospital Kermanshah University of Medical Sciences Kermanshah Iran Department of Internal Medicine Emam Reza Hospital Kermanshah Iran Department of Pathology Emam Reza Hospital Kermanshah Iran

AIM： To investigate the efficacy and tolerability of H pylori eradication in an omeprazole-based triple therapy with high and low dose of clarithromycin and amoxicillin. METHODS： One hundred and sixty H pylori positive patients were randomly assigned to two groups based on the following 2 wk investigation; （1） group A or low-dose regimen received omeprazole 20 mg b.i.d, clarithromycin 250 mg b.i.d and amoxicillin 500 mg b.i.d; and （2） group B or high-dose regimen received omeprazole 20 mg b.i.d, clarithromycin 500 mg b.i.d and amoxicillin 1000 mg b.i.d. During the study Hpylori status was assessed by histology and rapid urease test prior and by 13C-urea breath test 6 wk after the therapy. Standard questionnaires were administered to determine the compliance to treatment and possible adverse events of therapy. Data were subject to x^2 to compare the eradication rates in the two groups. The significant level of 95% （P ≤ 0.05） was considered statistically different. RESULTS： We found that the per-protocol eradication rate was 88% （68/77） in group A, and 89% （67/75） in group B. The intension-to-treat eradication rate was 85% （68/80） in group A and 83.75% （67180） in group B. Overall adverse events were 26% in group A and 31% in group B. The adverse events were generally mild in nature and tolerated well in both groups with a compliance of 98% in group A vs 96% in group B. CONCLUSION： The omeprazole-based low dose regimen of darithromycin and amoxicillin for two weeks in Hpylori eradication is as effective as high dose regimen in Iranian population.

关键词： Triple therapy Hpy/ori Amoxicillin Clarithromycin Low-dose regimen

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Effect of loading direction on interaction of two pre-existing open and closed flaws in a rock-like brittle material

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Underground Space 2020年第3期5卷 242-257页

作者： mahtab Alitalesh Mahmoud Yazdani Ahmadali Fakhimi Marjan Naeimabadi School of Civil and Environmental Engineering Tarbiat Modares UniversityTehranIran Department of Mineral Engineering New Mexico TechSocorroNMUSA

Investigations of the growth,interaction,and coalescence of cracks are important because they help to provide tools for the more realistic modeling of rock masses containing low persistence discontinuities and better estimations of the strength and stiffness of a rock *** the coalescence mechanism is useful for justifying the mechanism of continental crustal deformation,evaluating the structural failure of slopes with rock bridges,and analyzing the stability of tunnels when a mode I or mix mode failure mechanism is *** evaluation of crack growth can provide valuable information about the mechanism for the formation of new geological structures,and the formation,evolution,and growth of *** paper reports the results of diametrical compression tests on rocklike disk-shaped *** specimen contained two pre-existing open or closed *** growth,interaction,and coalescence of the pre-existing flaws were investigated both physically and numerically.A hybrid bonded particle-finite element system was used in the numerical *** results of the physical and numerical studies were in good *** particular,the induced crack patterns showed close agreement in the physical and numerical *** microscope image processing was used in the physical tests to study the dislocations along the initial *** was shown that wing crack formation was responsible for the failure of the specimen when flaws were inclined with respect to the loading *** crack growth and linkage were shown to be affected by the friction between faces of the *** addition,the slip distributions at the flaws surfaces were illustrated and examined to understand the crack propagation *** effects of the flaws on the disk failure loads were assessed both numerically and experimentally as well.

关键词： Pre-existing flaws Brazilian disk Fracture mechanics Crack propagation Coalescence Bonded particle simulation

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Biostratigraphy,Microfacies and Depositional Environment of the Sarvak Formation at the Pyun Anticline(Zagros Basin,Southwest of Iran)

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Acta Geologica Sinica(English Edition) 2021年第5期95卷 1647-1667页

作者： mahtab DOUSTI MOHAJER Massih AFGHAH Mohammadsadegh DEHGHANIAN Seyed Jamal SHEIKH ZAKARIAII Department of Geology Science and Research BranchIslamic Azad UniversityTehranIran Department of Geology Shiraz BranchIslamic Azad UniversityShirazIran Department of Geology Bandar Abbas BranchIslamic Azad UniversityBandar AbbasIran

The Sarvak Formation is a carbonate sequence of Late Albian–Early Turonian age in Zagros Basin in *** this investigation,the Sarvak Formation at the Pyun Anticline section(Izeh Zone)has been *** consists of 797 m thick limestone which overlies the Kazhdumi Formation conformably and underlies the Gurpi Formation unconformably at the Pyun Anticline.A very rich fossil association(85 genera and 132 species)characterizes the Pyun *** on the stratigraphic distribution of diagnosed foraminifera,five biozones are established:1,Muricohedbergella-Globigerinelloides *** zone(Late Albian);2,Praealveolina iberica-Chrysalidina gradata interval zone(Early Cenomanian);3,Chrysalidina gradata-Cisalveolina fraasi(fallax)and *** interval zone(Middle Cenomanian);4,***(fallax)and ***-Praetaberina bingistani assemblage zone(Late Cenomanian);5,Nezzazatinella picardi-MangashtiaDicyclina assemblage zone(Early Turonian).Based on the petrographic and sedimentological analyses,some 13 carbonate microfacies were *** investigated microfacies confirm a ramp-type *** microfacies,from distal to proximal environments,consist of:MF1:planktonic foraminifera wackestone-packstone;MF2:Oligostegina planktonic foraminifera wackestone to packstone;MF3:planktonic-benthic foraminifers sponge spicules wackestonepackstone;MF4:rudist floatstone;MF5:rudist rudstone;MF6:bioclast intraclast grainstone;MF7:peloid intraclast grainstone;MF8:benthic foraminifers rudist grainstone-packstone;MF9:peloid bioclast grainstone-packstone;MF10:bioclast(benthic foraminifers)wackestone-packstone;MF11:peloid bioclast packstone;MF12:dacycladacea benthic foraminifera packstone-wackestone;MF13:miliolids wackestone-packstone.

关键词： Sarvak Formation biostratigraphy microfacies Pyun Izeh Zone Zagros Basin

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