检索结果-南通市图书馆

High Voltage 2024年第2期9卷 495-507页

作者： Shahram Negari davoud Esmaeil Moghadam Integrated Power Services ClevelandOhioUSA Valeo eAutomotive Germany GmbH ErlangenGermany

Insulation systems in high-voltage electric machines play a pivotal role in the reliable operation and longevity of the ***-based insulation materials have proven to possess and maintain excellent dielectric properties in the long run and prevent premature insulation *** qualifications tests,such as voltage endurance,are outlined in IEC and IEEE *** authors,however,take a different parametric approach,opting for reliability assessment of insulation systems using derived three-parameter Weibull ***,instead of simple pass–fail criteria,empirical data is employed to determine failure rate probabilities quantitatively and *** data,including breakdown,dissipation factor,and partial discharge mea-surements,are used to construct the Weibull distribution model to predict fault and failure rates and calculate hazard *** rigorous examinations interpreted through the analytical model help assess insulation system resilience and particularly the impact of electrical field stress and mica *** of electrical stress from 66.75 to 71.20 V/mil demonstrated how the mean time to failure of the system changed from 146.4 to 85.1 at 3 Un,hence identifying opportunities for design improvement and uncovering performance ***,the developed framework enhances comprehension of insulation system failure probabilities,guiding design decisions and ensuring a secure and reliable operation of electrical machines across applications.

关键词： insulation parametric approach

Spatial distribution of sand flies(Diptera: Psychodidae; Larroussius group), the vectors of visceral leishmaniasis in Northwest of Iran

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2018年第9期8卷 425-430页

作者： Eslam Moradi-Asl Yavar Rassi davoud adham Ahmad Ali Hanafi-Bojd Abedin Saghafipour Sayena Rafizadeh Department of Public Health School of Public Health Ardabil University of Medical Sciences Department of Medical Entomology and Vector Control School of Public Health Tehran University of Medical Sciences Department of Public Health Faculty of Health Qom University of Medical Sciences Ministry of Health National Institute for Medical Research Development

Objective: To determine spatial distribution of sand flies(Diptera: Psychodidae; Larroussius group), the vectors of visceral leishmaniasis in Ardabil province, Northwest of ***: Sand flies were collected using sticky traps from the 30 selected points in Ardabil province, during May-November *** MaxEnt model in GIS software was used for ***: A total of 2 794 specimens of sand flies were collected, of which 33% were Larroussius subgenus sand *** kandelakii and Phlebotomus wenyoni were the highest and lowest collected species *** on the modeling, four areas in the province were identified with more than 70% probability of the presence of Larroussius group vectors which were at risk of visceral leishmaniasis disease ***: The distribution of Larroussius subgenus sand flies was observed in all parts of *** the northern parts of the province(Germi and Bilesavar counties) as well as central part(Ardabil and Meshkinshahr counties) were of great importance in terms of the presence of Larroussius subgenus sand flies and the possibility of transmission of the visceral leishmaniasis.

关键词： Larroussius subgenus Sand fly Ardabil Modeling Iran

Microstructure and phase formation of mullite-Pr6O11 composite prepared by spark plasma sintering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2023年第2期41卷 283-289页

作者： Ehsan Ghasali davoud Ghahremani Yasin Orooji Aida Faeghi-nia Asghar Kazem-zadeh Touradj Ebadzadeh College of Geography and Environmental Sciences Zhejiang Normal UniversityJinhua 321004China Ceramic Dept. Materials and Energy Research CenterAlborzIran Department of Engineering Maybod BranchIslamic Azad UniversityMaybodIran

The present work investigates the effect of high praseodymium oxide(Pr6O11)content on the microstructure and phase formation of mullite(3Al_(2)O_(3)·2SiO_(2))precursor by means of the spark plasma sintering process.30 wt%Pr6O11was added to a mullite precursor consisting of aluminum nitrate nonahydrate and tetraethyl orthosilicate through a high energy mixer mill in ethanol *** spark plasma sintering was performed at a te mperature of 1200℃under 23 Pa vacuum co nditions by applying initial and final pressure of 10 and 30 MPa,*** analysis confirms the existence of mullite,alumina,Pr6O11,Pr2O3and quartz as the only crystalline *** images reveal an interesting deposition of hexagonal-shaped Al_(2)O_(3)particles on polished surfaces and complex oxide phases of the fiber network adhering to alumina particles in the form of tails seen on the fracture ***,the bending strength of 213±21 MPa,Vickers hardness of 9.3±0.1 MPa and fracture toughness of6.21±0.12 MPa·m1/2are obtained for the prepared composite.

关键词： Mullite Pr6O11 Composite Spark plasma sintering Rare earths

Exploring the criteria and factors affecting firefighters’resilience:A qualitative study

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Traumatology 2022年第2期25卷 107-114页

作者： Ahad Heydari Abbas Ostadtaghizadeh Ali Ardalan Abbas Ebadi Iraj Mohammadfam davoud Khorasani-Zavareh Department of Health in Emergencies and Disasters School of Public HealthTehran University of Medical SciencesTehranIran Behavioral Sciences Research Center Life Style InstituteBaqiyatallah University of Medical SciencesTehranIran Nursing Faculty Baqiyatallah University of Medical SciencesTehranIran Center of Excellence for Occupational Health Occupational Health and Safety Research CenterSchool of Public HealthHamadan University of Medical SciencesHamadanIran Workplace Health Promotion Research Center(WHPRC) Shahid Beheshti University of Medical SciencesTehranIran Department of Health in Emergencies and Disasters School of Public Health and SafetyShahid Beheshti University of Medical SciencesTehranIran

Purpose:Firefighters are exposed to high levels of occupational risk factors,such as safety risks,chemical,ergonomic,and physical hazards that may jeopardize their *** overcome these hazards,firefighters must be physically,mentally,and personally fit to *** study aimed to explore the criteria and factors affecting firefighters'resilience based on stakeholders’***:This qualitative study was carried out using conventional content *** total,21 face-to-face interviews were conducted by firefighters who were experienced in the *** interviews were carried out from July 2019 to January *** data were collected using 3 unstructured interviews and then resumed by 18 semi-structured *** analysis was done using Graneheim ***:The participants had more than 5 years of experience in the field of search and *** extracted codes through data analysis were classified into 3 main categories(individual,organizational,and social factors),9 sub-categories(mental,physical,occupational,managerial,colleagues-related,equipment-related,environmental,community-related,and family-related factors),as well as 19 sub-sub-categories and 570 ***:Firefighters'personality,physical condition,behavior and psychological characteristics can affect their resilience along with organizational and management factors that play significant role in people's *** a tool for assessing resilience can help decision makers to have a real depict of firefighters'job qualifications.

关键词： Qualitative research Safety Resilience Firefighters

Urban restaurants and online food delivery during the COVID-19 pandemic:a spatial and socio-demographic analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2023年第1期16卷 1725-1751页

作者： Bakhtiar Feizizadeh davoud Omrazadeh Mohammad Ghasemi Samaneh Bageri Tobia Lakes Robert Kitzmann Abolfazl Ghanbari Thomas Blaschke Department of Remote Sensing and GIS University of TabrizTabrizIran Department of Geography Humboldt-Universität zu BerlinBerlinGermany IN3 Universitat Oberta de CatalunyaBarcelonaSpain Department of Geoinformatics-Z_GIS University of SalzburgSalzburgAustria

In this research,we analyzed the delivery service areas of restaurants,customer satisfaction,and restaurant sales of urban restaurants during the COVID-19 *** obtained the datasets on food ordering options and restaurant rankings based on Google Maps,Open Street Map,and widely known online food order applications in *** on this analysis we further modeled suitable areas for future extension of *** analyzed the online food order data of restaurants’sales and food delivery reports for 1050 restaurants in the city of *** collected and analyzed data on the restaurant locations,the number of food orders for each restaurant,and the number of customers and their *** results revealed that the spatial dimension of the newly emerging food delivery areas is of utmost importance for the success of *** indicates that an optimal location is not longer only dependent on factors like population density and competitors in the direct vicinity but on the services density even from more distant *** results indicate that an optimized spatial distribution of the restaurants together with efficient quality in services can contribute to optimistic urban development.

关键词： Urban restaurant services area mapping success factors customer satisfaction COVID-19 spatial analysis

Sterilization of Turmeric by Atmospheric Pressure Dielectric Barrier Discharge Plasma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2013年第11期15卷 1122-1126页

作者： Setareh SALARIEH davoud DORRANIAN Biotechnology Engineering Lab. Plasma Physics Research Center Science and Research Branch Islamic Azad University

In this study atmospheric pressure dielectric barrier discharge （DBD） plasma has been employed for sterilizing dry turmeric powders. A 6 kV, 6 kHz frequency generator was used to generate plasma with Ar, Ar/Ou, He, and He/O2 gases between the 5 mm gap of two quartz covered electrodes. The complete sterilization time of samples due to plasma treatment was measured. The most important contaminant of turmeric is bacillus subtilis. The results show that the shortest sterilization time of 15 rain is achieved by exposing the samples to Ar/O2 plasma. Survival curves of samples are exponential functions of time and the addition of oxygen to plasma leads to a significant increase of the absolute value of time constant of the curves. Magnitudes of protein and DNA in treated samples were increased to a similar value for all samples. Taste, color, and solubility of samples were not changed after the plasma treatment.

关键词： sterilization, DBD plasma, atmospheric pressure, decontamination, positive(negative) Gram bacteria radio frequency plasma bacillus subtilis

Estimation of photolysis half-lives of dyes in a continuous-flow system with the aid of quantitative structure-property relationship

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2014年第5期8卷 683-692页

作者： davoud BEIKNEJAD Mohammad Javad CHAICHI Faculty of Chemistry University of Mazandaran Babolsar 47416-95447 Iron

In this paper the photolysis half-lives of the model dyes in water solutions and under ultraviolet （UV） radiation were determined by using a continuous-flow spectrophotometric method. A quantitative structure- property relationship （QSPR） study was carried out using 21 descriptors based on different chemometric tools including stepwise multiple linear regression （MLR） and partial least squares （PLS） for the prediction of the photolysis half-life （t1/2） of dyes. For the selection of test set compounds, a K-means clustering technique was used to classify the entire data set, so that all clusters were properly represented in both training and test sets. The QSPR results obtained with these models show that in MLR-derived model, photolysis half-lives of dyes depended strongly on energy of the highest occupied molecular orbital （EHoMO）, largest electron density of an atom in the molecule （ED^＋） and lipophilicity （logP）. While in the model derived from PLS, besides aforementioned EHOMO and ED^＋ descriptors, the molecular surface area （Sm）, molecular weight （M-W）, electronegativity （X）, energy of the second highest occupied molecular orbital （EHoMO- 1） and dipole moment （μ） had dominant effects on logt1/2 values of dyes. These were applicable for all classes of studied dyes （including monoazo, disazo, oxazine, sulfo- nephthaleins and derivatives of fluorescein）. The results were also assessed for their consistency with findings from other similar studies.

关键词： dye photolysis half-life quantitative structure-property relationship continuous-flow stepwise multiple linear regression partial least squares

Multi-objective robot motion planning using a particle swarm optimization model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第8期11卷 607-619页

作者： Ellips MASEHIAN davoud SEDIGHIZADEH Faculty of Engineering Tarbiat Modares University

Two new heuristic models are developed for motion planning of point robots in known *** first model is a combination of an improved particle swarm optimization (PSO) algorithm used as a global planner and the probabilistic roadmap (PRM) method acting as a local obstacle avoidance *** the PSO component,new improvements are proposed in initial particle generation,the weighting mechanism,and position-and velocity-updating ***,two objective functions which aim to minimize the path length and oscillations,govern the robot’s movements towards its *** PSO and PRM components are further intertwined by incorporating the best PSO particles into the randomly generated *** second model combines a genetic algorithm component with the PRM *** this model,new specific selection,mutation,and crossover operators are designed to evolve the population of discrete particles located in continuous *** comparisons of the developed models with each other,and against the standard PRM method,show the advantages of the PSO method.

关键词： Robot motion planning Particle swarm optimization Probabilistic roadmap Genetic algorithm

A comparison of the effect of Vitamin D and Vitamin E supplementations,alone,and in combination,on reducing the intensity and duration of dysmenorrhea in women:A randomized controlled trial

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Nursing 2023年第1期5卷 21-26页

作者： Tahereh BEHROUZI LAK Nader AGHAKHANI davoud VAHABZADEH Samereh EGHTEDAR Rozita CHERAGHI Nazafarin GHASEMZADEH Vahid ALINEJAD Maryam MESGARZADEH Reproductive Health Research Center Urmia University of Medical SciencesUrmiaIran Food and Beverages Safety Research Center Urmia University of Medical SciencesUrmiaIran Department of Nutrition and Biochemistry Faculty of MedicineIlam University of Medical SciencesIlamIran Department of Medical Surgical Nursing School of Nursing and MidwiferyUrmia University of Medical SciencesUrmiaIran Department of Medical Ethics Faculty of MedicineUrmia University of Medical SciencesUrmiaIran Department of Biostatics Faculty of MedicineUrmia University of Medical SciencesUrmiaIran Department of Midwifery School of Nursing and MidwiferyUrmia University of Medical SciencesUrmiaIran

Objective:The aim of this study is to compare the effect of Vitamin D and Vitamin E supplementations,alone,and in combination,on reducing the intensity and duration of dysmenorrhea in women who were referred to the Kowsar gynecological clinics of Shahid Motahari Hospital of Urmia University of Medical *** and Methods:A double-blinded clinical trial was conducted on 112 women with dysmenorrhea who were randomly allocated into the four study ***,100 women complete the study and received capsules containing a placebo(n=25),1000 IU of Vitamin D(n=25),400 mg of Vitamin E(n=25),and 1000 IU of Vitamin D+400 mg of Vitamin E(n=25)every 24 h for 2 consecutive months at the beginning of the menstrual *** pain intensity and duration among groups were compared before and after the ***:The mean menstrual pain duration in all three experimental groups(Vitamin E,Vitamin D,and the combination of them)was lower than the placebo group(all P<0.05),and the mean pain intensity scores in all three experimental groups were significantly lower than the placebo group(all P<0.05).The results(means)for all of the drugs administered at the end of the 2nd month were better than the 1st month(all P<0.01).Conclusions:Vitamin E and Vitamin D,as well as their combination,are recommended as an effective and safe treatment for the management of the complications of dysmenorrhea.

关键词： Duration dysmenorrhea intensity randomized controlled trial Vitamin D Vitamin E women

Infrared thin layer drying of saffron(Crocus sativus L.) stigmas:Mass transfer parameters and quality assessment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第4期25卷 426-432页

作者： Mehdi Torki-Harchegani davoud Ghanbarian Vida Maghsoodi Ahmad Moheb Young Researchers and Elite Club Shahrekord BranchIslamic Azad University Department of Mechanical Engineering of Biosystems Shahrekord University Department of Chemical and Petroleum Engineering Sharif University of Technology Department of Chemical Engineering Isfahan University of Technology

Saffron is the most precious and expensive agricultural product. A dehydration treatment is necessary to convert Crocus sativus L. stigmas into saffron spice. To the best of our knowledge, no information on mass transfer parameters of saffron stigmas is available in the literature. This study aimed at investigating the moisture transfer parameters and quality attributes of saffron stigmas under infrared treatment at different temperatures(60,70, …, 110 °C). It was observed that the dehydration process of the samples occurred in a short accelerating rate period at the start followed by a falling rate period. The effective moisture diffusivity and convective mass transfer coefficient were determined by using the Dincer and Dost model. The diffusivity values varied from1.1103 × 10^(-10)m^2·s^(-1)to 4.1397 × 10^(-10)m^2·s^(-1) and mass transfer coefficient varied in the range of 2.6433 × 10^(-7)–8.7203 × 10^(-7)m·s^(-1). The activation energy was obtained to be 27.86 k J·mol^(-1). The quality assessment results showed that the total crocin content increased, when the temperature increased up to90 °C but, in higher temperatures, the amount of crocin decreased slightly. The total safranal content of the samples decreased slightly when drying temperature increased from 60 °C to 70 °C and then continuously increased up to 110 °C. Also, the amount of picrocrocin increased from 83.1 to 93.3 as the drying temperature increased from 60 °C to 100 °C.

关键词：藏花红外线的弄干有效扩散性集体转移系数化学作文