检索结果-南通市图书馆

Application of dielectric barrier discharge(DBD) plasma packed with glass and ceramic pellets for SO_2 removal at ambient temperature: optimization and modeling using response surface methodology

引用

Plasma Science and Technology 2020年第10期22卷 100-110页

作者： Niloofar DAMYAR ali khavanin Ahmad JONIDI FAFARI Hasan ASILIAN Ramazan MIRZAEI Department of Occupational Health Engineering Faculty of Medical SciencesTarbiat Modares University14115-111 TehranIran Department of Environmental Health Engineering School of Public HealthIran University of Medical Sciences14665-354 TehranIran Department of Occupational Health Engineering.School of Public Health Mashhad University of Medical Sciences13131-99137 MashhadIran

Air pollution is a major health problem in developing countries and has adverse effects on human health and the environment. Non-thermal plasma is an effective air pollution treatment technology. In this research, the performance of a dielectric barrier discharge(DBD) plasma reactor packed with glass and ceramic pellets was evaluated in the removal of SO_2 as a major air pollutant from air in ambient temperature. The response surface methodology was used to evaluate the effect of three key parameters(concentration of gas, gas flow rate, and voltage) as well as their simultaneous effects and interactions on the SO2 removal process. Reduced cubic models were derived to predict the SO_2 removal efficiency(RE) and energy yield(EY). Analysis of variance results showed that the packed-bed reactors(PBRs) studied were more energy efficient and had a high SO2 RE which was at least four times more than that of the non-packed reactor. Moreover, the results showed that the performance of ceramic pellets was better than that of glass pellets in PBRs. This may be due to the porous surface of ceramic pellets which allows the formation of microdischarges in the fine cavities of a porous surface when placed in a plasma discharge zone. The maximum SO_2 RE and EY were obtained at 94% and 0.81 g kWh^(-1),respectively under the optimal conditions of a concentration of gas of 750 ppm, a gas flow rate of 2lmin^(-1), and a voltage of 18 kV, which were achieved by the DBD plasma packed with ceramic pellets. Finally, the results of the model's predictions and the experiments showed good agreement.

关键词： sulfur dioxide packed-bed plasma glass pellets ceramic pellets response surface methodology(RSM)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improving the Sound Absorption Properties of Flexible Polyurethane (PU) Foam using Nanofibers and Nanoparticles

引用

Sound & Vibration 2019年第5期53卷 207-222页

作者： Roohalah Hajizadeh ali khavanin Mohammad Barmar Ahmad Jonidi Jafari Somayeh Farhang Dehghan Department of Occupational Health Engineering Faculty of Medical SciencesTarbiat Modares UniversityTehranIran Department of Polyurethane Iran Polymer and Petrochemical InstituteTehranIran Research Center for Environmental Health Technology Department of Environmental Health EngineeringIran University of Medical SciencesTehranIran Department of Occupational Health and Safety at Work Workplace Health Promotion Research CenterSchool of Public Health and SafetyShahid Beheshti University of Medical SciencesTehranIran

Polyurethane foam as the most well-known absorbent materials has a suitable absorption coefficient only within a limited frequency *** aim of this study was to improve the sound absorption coefficient of flexible polyurethane(PU)foam within the range of various frequencies using clay nanoparticles,polyacrylonitrile nanofibers,and polyvinylidene fluoride *** response surface method was used to determine the effect of addition of nanofibers of PAN and PVDF,addition of clay nanoparticles,absorbent thickness,and air gap on the sound absorption coefficient of flexible polyurethane foam(PU)across different frequency *** absorption coefficient of the samples was measured using Impedance Tubes *** clay at low thicknesses as well as polyacrylonitrile nanofibers and polyvinyl fluoride nanofibers at higher thicknesses had a greater positive effect on absorption *** mean sound absorption coefficient in the composite with the highest absorption coefficient at middle and high frequencies was 0.798 and 0.75,*** comparison with pure polyurethane foam with the same thickness and air gap,these values were 2.22 times at the middle frequencies and 1.47 times at high frequencies,*** porosity rose with increasing nano clay,but decreased with increasing polyacrylonitrile nanofibers and polyvinyl fluoride *** results indicated that the absorption coefficient was elevated with increasing the thickness and air *** study suggests that the use of a combination of nanoparticles and nanofibers can enhance the acoustic properties of flexible polyurethane foam.

关键词： Sound absorption coefficient flexible polyurethane foam nano clay polyacrylonitrile nanofibers polyvinyl fluoride nanofibers

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Improving the Cellular Characteristics of Aluminum Foam for Maximum Sound Absorption Coefficient Using Genetic Algorithm

引用

Sound & Vibration 2021年第2期55卷 117-130页

作者： Mohammad Javad Jafari Mohsen Niknam Sharak ali khavanin Touraj Ebadzadeh Mahmood Fazlali Rohollah Fallah Madvari Department of Occupational Health Engineering School of Public Health and SafetyShahid Beheshti University of Medical SciencesTehranIran Mechanical Engineering Department of Mechanical EngineeringUniversity of BirjandBirjandIran Department of Occupational Health Engineering Faculty of Medical SciencesTarbiat Modares UniversityTehranIran Department of Ceramics Materials and Energy Research CenterAlborzIran Department of Data and Computer Science Faculty of Mathematical SciencesShahid Beheshti UniversityTehranIran Student Research Committee Department of Occupational Health EngineeringSchool of Public Health and SafetyShahid Beheshti University of Medical SciencesTehranIran Department of Occupational Health School of Public HealthShahid Sadoughi University of Medical SciencesYazdIran

Fabricating of metal foams with desired morphological parameters including pore size,porosity and pore opening is possible now using sintering ***,if it is possible to determine the morphology of metal foam to absorb sound at a given frequency,and then fabricate it through sintering,it is expected to have optimized metal foams for the best sound *** sound absorption models such as Lu model describe the relationship between morphological parameters and the sound absorption *** this study,the Lu model was used to optimize the morphological parameters of aluminum metal foam for the best sound absorption *** this purpose,the Lu model was numerically solved using written codes in MATLAB *** validating the proposed codes with benchmark data,the genetic algorithm(GA)was applied to optimize the affecting morphological parameters on the sound absorption *** optimization was carried out for the thicknesses of 5 mm to 40 mm at the sound frequency range of 250 Hz–8000 *** optimized parameters ranged from 50%to 95%for porosity,0.1 mm to 4.5 mm for pore size,and 0.07 mm to 0.6 mm for pore opening *** result of this study was applied to fabricate the desired aluminum metal foams for the best sound *** novel approach applied in this study,is expected to be successfully applied in for best sound absorption in desired frequencies.

关键词： Acoustic model Genetic Algorithm(GA) metal foam optimization Sound Absorption Coefficient(SAC)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Environmental Pollution Bioindication Based on Ficus benjamina L. Leaf Reflectance in the City of Abidjan, Côte d’Ivoire

引用

Open Journal of Air Pollution 2016年第2期5卷 55-63页

作者： Zamblé Fidèle Tra Bi Yao Sadaiou Sabas Barima Djédoux Maxime Angaman ali Reza khavanin Zadeh Karidia Traoré Unité de Formation et de Recherche en Environnement Université Jean Lorougnon Guédé Daloa C&#244te d’Ivoire Department of Bioscience Engineering University of Antwerp Antwerp Belgium Unité de Formation et de Recherche en Agroforesterie Université Jean Lorougnon Guédé Daloa C&#244te d’Ivoire

The air in African cities is increasingly polluted mainly due to human activities. A bioindication technical of urban air quality based on active remote sensing might be an alternative to existing physico-chemical methods. Reflectance measurements in the visible spectrum have been carried out at the adaxial and abaxial sides of Ficus benjamina L. leaves in the city of Abidjan, Côte d’Ivoire, with a precision digital camera. Leaves were collected in industrial zones and in parks. The impact of air pollution on leaf physiological as well as structural characteristics in these two contrasts urban environments was determined by Dorsiventral Leaf Reflectance Correlation (DRLC) and dorsiventral leaf reflectance asymmetry quantitatively defined with Normalized Dorsiventral Asymmetry Index (NDAI). Species leaf susceptibility to air pollution from season to season was determined by NDAI seasonal variation. Leaf reflectance measurements allowed the estimation of environmental stress level among industrial areas and parks. NDAI and DLRC were significantly higher in industrial zones compared to parks. NDAI values were found significantly higher for major rainy season compared to major dry season, indicating probably that F. benjamina leaf structure changes were increased from one season to another. Thereby, assessment of urban air quality can be done using leaves reflectance in the visible spectrum.

关键词： Bioindication Air Pollution Reflectance Visible Spectrum Côte d’Ivoire

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Functional reconstruction of lower extremity nerve injuries

引用

Plastic and Aesthetic Research 2022年第1期9卷 308-324页

作者： Cecil S.Qiu Philip J.Hanwright Nima khavanin Sami H.Tuffaha Department of Plastic and Reconstructive Surgery Johns Hopkins University School of MedicineBaltimoreMD 21287USA

Peripheral nerve injuries(PNI)in the lower extremity are an uncommon but highly morbid *** advances in our understanding of nerve physiology and microsurgical techniques have inspired renewed faith in nerve surgery and sparked a creative renaissance in the tools,approaches,and reconstructive schemas available to surgeons in the management of lower extremity *** this article,we review the literature and provide a principles-based approach for the surgical management of lower extremity PNIs with an emphasis on techniques for functional reconstruction after complete nerve *** principles in management include early diagnosis with electrodiagnostics and imaging,early surgical exploration,and opting for nerve and tendon transfers when primary reconstruction of the injured nerve is unfavorable(e.g.,delayed reconstruction,unavailability of proximal or distal nerve stumps,or long regenerative distance).The goal of functional reconstruction should be to restore independent gait,so understanding the roles of major neuromuscular units during the gait cycle informs the selection of donor nerves and tendons for *** on these principles and literature to date,specific algorithms for surgical management are presented for femoral,sciatic,tibial,and common peroneal *** recognize limitations of the current literature,namely the predominance of case series evidence,and call for the accrual of more patient data in surgical management of PNIs.

关键词： Nerve nerve transfer tendon transfer gait

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：