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

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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

Sterilization of Turmeric by Atmospheric Pressure Dielectric Barrier Discharge Plasma

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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

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

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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 novel approach towards parametric assessment of reliability and resilience of high voltage mica-based insulation systems by statistical analysis of experimental failure data

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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

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

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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 ℃）. 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^-10m^2·s^-1to 4.1397 × 10^-10m^2·s^-1 and mass transfer coefficient varied in the range of 2.6433 × 10^-7–8.7203 × 10^-7m·s^-1. The activation energy was obtained to be 27.86 kJ·mol^-1. The quality assessment results showed that the total crocin content increased, when the temperature increased up to90 ℃ 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 ℃ to 70 ℃ and then continuously increased up to 110 ℃. Also, the amount of picrocrocin increased from 83.1 to 93.3 as the drying temperature increased from 60 ℃ to 100 ℃.

关键词： drying moisture Infrared expensive slightly convective varied dehydration spice convert

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

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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

Weighing and Prioritizing Noise Control Methods Using the Delphi Technique and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) in an Iranian Tire Manufacturing Factory

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Sound & Vibration 2020年第3期54卷 201-213页

作者： Mohammad Reza Ghotbi-Ravandi davoud Hassanvand Sajad Zare Milad Beytollahi Associate Professor Department of Occupational HealthSchool of Public HealthKerman University of Medical Sciences and Health ServicesKermanIran Master of Occupational Health Student Research CommitteeSchool of Public HealthKerman University of Medical Sciences and Health ServicesKermanIran Assistant Professor Department of Occupational HealthSchool of Public HealthKerman University of Medical Sciences and Health ServicesKermanIran Department of Industrial Engineering Faculty of EngineeringShahid Bahonar University of KermanKermanIran

Undoubtedly,noise has become a major hazardous issue in today’s industrial world,with a lot of people suffering from exposure to excessive noise in their work *** study was conducted to weigh and prioritize noise control methods in an Iranian tire manufacturing complex in *** Delphi method and the Technique for Order Preference by Similarity and an Ideal Solution(TOPSIS)were utilized for this *** cross-sectional,descriptive study was conducted in the baking hall of an Iranian tire manufacturing factory in *** weigh and prioritize noise control methods,Analytic Hierarchy Process(AHP)and TOPSIS were *** total,4 criteria and 8 alternatives were *** AHP and TOPSIS questionnaire was then designed to prioritize noise control methods in the light of the objectives,criteria,and ***,the collected data were fed into Expert Choise.V.11 and Excel and data analysis was carried out using *** results of data analysis indicated that the inconsistency rate in all the cases was smaller than 10%,hence the consistency of the responses was *** to the TOPSIS results and experts’opinions about the criteria,implementation and maintenance cost(with a weight of 0.481)and method effectiveness and efficiency(with a weight of 0.046)had the highest and lowest priority *** on the weights TOPSIS,the appropriate methods for controlling noise in tire manufacturing are designing and manufacturing silencer,requiring people in charge to quickly fix the leaks and change baking press washers on time.

关键词： Ranking noise control methods TOPSIS delphi technique

Selective leaching of arsenic from copper converter flue dust by Na2S and its stabilization with Fe2(SO4)3

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Transactions of Nonferrous Metals Society of China 2020年第6期30卷 1674-1686页

作者： Amirhossein SHAHNAZI Sadegh FIROOZI davoud HAGHSHENAS FATMEHSARI Department of Mining and Metallurgical Engineering Amirkabir University of Technology424 Hafez Ave.Tehran 15875-4413Iran

The alkaline leaching of arsenic (As2O3) by Na2S, together with its precipitation by Fe2(SO4)3 was studied. Response surface methodology based on central composite design was employed to quantify and qualify the effect of pertinent factors and to develop statistical models for optimization purposes. Based on the obtained results, 89% of arsenic is removed from the dust under following optimum predicted conditions: Na2S concentration of 100 g/L and solid to liquid ratio of 0.163 g/mL at 80 °C. It is found that solid to liquid ratio and Na2S concentration are the significant factors influencing the leaching process. In the precipitation process, more than 99.93% of arsenic from the leaching solution is removed in the form of amorphous ferric arsenate, at pH 4.8 when Fe3+ to arsenic and H2O2 to arsenic molar ratios are set at 5:1 and 4:1, respectively. Also, Fe3+ to arsenic ratio and pH are the most significant factors, and the interaction between these terms is significant.

关键词： flue dust arsenic response surface methodology alkaline leaching precipitation

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

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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