检索结果-南通市图书馆

Color and Gloss Changes of a Lignin-Based Polyurethane Coating under Accelerated Weathering

Journal of Renewable Materials 2024年第2期12卷 305-323页

作者： Fatemeh Hassani Khorshidi Saeed Kazemi najafi Farhood najafi Antonio Pizzi Dick Sandberg Rabi Behrooz Department of Wood Science and Technology Faculty of Natural ResourcesTarbiat Modares UniversityTehranIran Department of Resin and Additives Institute for Color Science and TechnologyP.O.Box 16765-654TehranIran LERMAB University of LorraineBlvd des AiguillettesNancy54000France Wood Science and Engineering LuleåUniversity of TechnologySkellefteåSweden

The purpose of this research study was to investigate the properties of polyurethane coatings based on lignin nano-particles.For this purpose,the prepared coatings were applied to pine wood surfaces and weathered artificially.Subsequently,color and gloss of the coatings were measured before and after the weathering test.Field emission scanning electron microscopy(FE-SEM)micrographs prepared from the coatings showed that the average size of nano-particles in the polyurethane substrate was approximately 500 nm.Nuclear magnetic resonance(13C-NMR)spectroscopy showed that strong urethane bonds were formed in the nano-lignin-based polyurethane.Differential calorimetric analysis(DSC)test revealed that the glass-transition temperature(Tg)of lignin nanoparticles modified with diethylenetriamine(DETA)was 112.8℃ and Tg of lignin nano-particles modified with ethylenediamine(EDA)was 102.5℃,which is lower than the Tg of un-modified lignin(114.6℃)and lignin modified with DETA(126.8℃)and lignin modified with EDA(131.3℃).The coatings modified with lignin nano-particles had a greater change in gloss.The lignin nano-particles in the modified coating are trapping hydroxyl radicals which reduces photoactivity and yellowing of the polyurethane by about 3 times compared to unmodified polyurethane coatings.After weathering test,the nano-lignin-based coating had a rougher surface with a lower contact angle(0.78°)compared to the unmodified polyurethane coating(0.85°).

关键词： Amination propylene carbonate lignin biopolymer polyurethane coating polyol UN SDG 13

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

Examining the Effect of Hydroalcoholic Extract of Dracaena cinnabari on Sex Hormones and Ovarian and Uterine Tissues of Rats

引用

World Journal of Traditional Chinese Medicine 2024年第2期10卷 213-219页

作者： Elham najafi Bahareh Babaei Hoolari Akbar Karimi aliasghar Pilehvarian Department of Cellular Biology Genesis Evolution-Develoment Isfahan Payame Noor University Department of Anatomy School of Medicine Tehran University of Medical Sciences Department of Biology Group Faculty Member of Isfahan Payame Noor University

Introduction: Dracaena cinnabari is considered a rich source of phytochemicals used widely in traditional medicine. In the present study, the effect of D. cinnabari hydraulic extract on the reproductive system of female rats was investigated. Methods: The samples were randomly divided into four groups(six samples in each group), including three treatment groups and one control group, and all samples were kept at the same conditions. Hydraulic extract of D. cinnabari and injected intraperitoneally daily for 10 days, while physiological serum was used for injection in to the control group. After 10 days of injection, estrogen and progesterone levels were measured by enzyme immunoassay technique. After dissection, the ovaries and uterine tissues were isolated for histological examination, and tissue changes were carefully examined. Results: The results revealed that the levels of estrogen and progesterone in experimental Groups 2 and 3 had a significant increase(P < 0.001). Regarding tissue changes, a significant increase was observed in epithelial thickness(P < 0.001), number of corpus luteum(P < 0.01), and Graafian follicle(P < 0.01) in doses of 100 and 150 mg/kg. Conclusions: Based on the results, it seems that D. cinnabari extract has an effect on the ovarian follicles.

关键词： Dracaena cinnabari herbal medicine ovarian tissues reproductive sex hormones

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Situation analysis of cutaneous leishmaniasis in an endemic area,south of Iran

引用

Asian Pacific Journal of Tropical Medicine 2017年第1期10卷 88-93页

作者： Mansour Nazari Saman Nazari Ahmad ali Hanafi-Bojd Ali Najafi Sasan Nazari Department of Medical Entomology School of MedicineHamadan University of Medical SciencesHamadanIran Medical student Students Research CenterHamadan University of Medical SciencesHamadanIran Department of Medical Entomology and Vector Control School of Public HealthTehran University of Medical SciencesTehranIran Master of Medical Entomology Health Center of Kazerun cityIran

Objective: To update current situation of the cutaneous leishmaniasis(CL) in Kazerun County,southwest of Iran and to analyze the epidemiological aspects of the disease during 2005-2015,Methods: Data on CL were obtained from the Health Center of Kazerun County,and then were analyzed and mapped using SPSS and Arc GIS 10.3,Results: A total of 700 cases of CL were recorded during the study period with an overall decreasing trend from 2005 to 2015,More than 60% of the patients were inhabitants of rural areas and males were infected more than females,Although there was not a significant difference between gender,job categories,residence and CL infection(P>0.05),age groups were significantly different(P0.05),Most of the acute lesions were found to be present on the hand,leg and face,respectively,The average CL incidence in the study area was calculated as 24.9/100 000 population,A hot spot for the disease was found in southern part of the area(P<0.05),Conclusions: This study revealed that CL is present in Kazerun country,Thus,effective monitoring and sustained suveillance system is crucial in counteracting the disease,and if possible,to eliminate it.

关键词： Cutaneous leishmaniasis Epidemiological study Southern Iran

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

Isoimperatorin alleviates acetic acid-induced colitis in rats

引用

Asian Pacific Journal of Tropical Biomedicine 2024年第4期14卷 147-153页

作者： Saied Goodarzi Amir Hossein Abdolghaffari Behnaz najafi Mostafa Pirali Hamedani Saeed Tavakoli Mahshad Marvi Maryam Baeeri Narguess Yassa Abbas Hadjiakhoondi Mohammad Abdollahi Zahra Tofighi Medicinal Plants Research Center Faculty of PharmacyTehran University of Medical SciencesTehranIran Department of Toxicology and Pharmacology Faculty of PharmacyTehran Medical SciencesIslamic Azad UniversityTehranIran Department of Pharmacognosy Faculty of PharmacyTehran University of Medical SciencesTehranIran Medicinal Plants Research Center Institute of Medicinal PlantsACECRKarajIran International Campus School of Pharmacy Tehran University of Medical SciencesTehranIran Toxicology and Diseases group The Pharmaceutical Sciences Research CenterTehran University of Medical SciencesTehranIran Department of Toxicology and Pharmacology Faculty of PharmacyTehran University of Medical SciencesTehranIran

Objective:To investigate the effect of isoimperatorin on histopathological and biochemical changes in acetic acid-induced colitis rats.Methods:Colitis was induced by intracolonic administration of acetic acid solution(4%v/v)in rats.Rats were divided into six groups including the sham group,the negative control group,the dexamethasone-treated group,and the groups treated with isoimperatorin(0.1,1,and 10 mg/kg/d by gavage).The treatments were administered for three days and then colonic status was assessed by macroscopic,histopathological,and biochemical analyses.Results:Isoimperatorin significantly alleviated colonic damage in a dose-dependent manner and improved histological changes in rats with acetic acid-induced colitis.It also significantly reduced myeloperoxidase,TNF-α,IL-1β,and malodialdehyde levels.Conclusions:Isoimperatorin alleviates acetic acid-induced colitis in rats and may be a potential therapeutic agent for the treatment of colitis.

关键词： Isoimperatorin Inflammatory bowel disease Acetic acid Colitis TNF-α IL-1β

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

Market-based coordination of price-responsive demand using Dantzig-Wolfe decomposition method

Energy and AI

引用

Energy and AI 2023年第4期14卷 329-340页

作者： Foad najafi Matthias Fripp Department of Electrical Engineering University of Hawaii at Manoa2540 Dole StreetHonoluluHawaiiUnited States

The increasing penetration of Distributed Generation(DG)and Demand Responsive(DR)loads in power systems has necessitated the development of novel approaches to address the coordination problem of Price Responsive Devices(PRD).These PRDs are treated as self-interested players aiming to optimize their consumption patterns based on prevailing prices.In this paper,we propose a new algorithm based on the Dantzig-Wolfe(DW)Decomposition method,which tackles the coordination problem of self-interested PRDs in a distributed manner.Leveraging the distributed nature of the DW approach,we model the self-interested algorithms of PRDs as sub-problems within the DW framework.The coordinator,or grid operator,responsible for collecting the energy consumption information(energy bids)of PRDs,solves the master problem of the DW and determines the price signal accordingly.The proposed algorithm exhibits fast convergence as the sub-problems within DW,which could involve a large number of PRDs(potentially millions),can be solved simultaneously.Additionally,based on the DW theory,if the PRDs’subproblems are convex,reaching the optimal point(equivalent to Nash Equilibrium)is guaranteed within a limited number of iterations.To evaluate the proposed model,we conducted a simulation involving 200 participant households,each equipped with two types of loads:Electric Vehicles(EVs)as examples of inter-ruptible loads,and Electric Water Heaters(EWHs)as examples of Thermostatically Controlled Loads(TCLs).The results demonstrate that when the algorithm converges to the optimal point,both the generation cost and user payment(based on the marginal cost of generation)decrease.Furthermore,there is a significant reduction in the Peak to Average Ratio(PAR)of the aggregate load.

关键词： Demand-side management(DSM) Distributed optimization Dantzig-Wolfe algorithm Price responsive devices(PRD) Appliance coordination

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

Review of application of artificial intelligence techniques in petroleum operations

引用

Petroleum Research 2023年第2期8卷 167-182页

作者： Saeed Bahaloo Masoud Mehrizadeh Adel najafi-Marghmaleki Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Department of Petroleum Engineering School of Science and EngineeringKhazar UniversityBakuAzerbaijan Department of Petroleum Engineering Ahwaz Faculty of PetroleumPetroleum University of TechnologyAhwazIran

In the last few years,the use of artificial intelligence(AI)and machine learning(ML)techniques have received considerable notice as trending technologies in the petroleum industry.The utilization of new tools and modern technologies creates huge volumes of structured and un-structured data.Organizing and processing of these information at faster pace for the performance assessment and forecasting for field development and management is continuously growing as an important field of investigation.Various difficulties which were faced in predicting the operative features by utilizing the conventional methods have directed the academia and industry toward investigations focusing on the applications of ML and data driven approaches in exploration and production operations to achieve more accurate predictions which improves decision-making processes.This research provides a review to examine the use cases and application of AI and ML techniques in petroleum industry for optimization of the upstream processes such as reservoir studies,drilling and production engineering.The challenges related to routine approaches for prognosis of operative parameters have been evaluated and the use cases of performance optimizations through employing data-driven approaches resulted in enhancement of decision-making workflows have been presented.Moreover,possible scenarios of the way that artificial intelligence will develop and influence the oil and gas industry and how it may change it in the future was discussed.

关键词： Artificial intelligence Machine learning Upstream operation Oil and gas industry Petroleum systems Decision-making

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

Direct production of hydrogen peroxide over bimetallic CoPd catalysts:Investigation of the effect of Co addition and calcination temperature

引用

Green Energy & Environment 2023年第1期8卷 246-257页

作者： Hamidreza Nazeri alireza najafi Chermahini Zahra Mohammadbagheri Mirko Prato Department of Chemistry Isfahan University of Technology84154-83111IsfahanIran Materials Characterization Facility Istituto Italiano di TecnologiaVia Morego 3016163GenovaItaly

A series of CoPd/KIT-6 bimetallic catalysts with various Co:Pd molar ratios at different calcination temperatures were prepared and used for the direct synthesis of H_(2)O_(2) from H_(2) and O_(2).These catalysts were characterized by nitrogen adsorption-desorption,low and wide-angle X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),scanning electron microscopy(SEM),elemental mapping and energy-dispersive X-ray(EDX)methods.It was found that the particle size,electronic interactions,morphology,and textural properties of these catalysts as well as their catalytic activity in the reaction of H_(2) with O_(2) were affected by Co addition and different calcination temperatures.Also,the results showed that while the H_(2)O_(2) selectivity depends on Pd^(2+) species,the H_(2) conversion is related to Pd0 active sites.Among these catalysts,CoPd/KIT-6 calcined at 350℃(CoPd/KIT-350 catalyst)showed the best catalytic activity with 50%of H_(2)O_(2) selectivity and 51%conversion of H_(2).

关键词： Direct synthesis of hydrogen peroxide Co/Pd catalysts Selectivity The oxidation state of Pd Reusability

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

Effect of Amine Type on Lignin Modification to Evaluate Its Reactivity in Polyol Construction for Non-Isocyanate Polyurethanes(NIPU)

引用

Journal of Renewable Materials 2023年第5期11卷 2171-2190页

作者： Saeed Kazemi najafi Farhood najafi Antonio Pizzi Fatemeh Hassani Khorshidi Rabi Behrooz Department of Wood Science and Technology Faculty of Natural ResourcesTarbiat Modares UniversityTehranIran Department of Resin and Additives Institute for Color Science and TechnologyTehranIran LERMAB University of LorraineBlvd des AiguillettesNancyFrance

Polyols are groups of organic compounds which contain carbon and are randomly linked to other atoms,especially carbon-carbon and carbon-hydrogen.These compounds are mainly used as reactants to make other polymers.Among biopolymers,lignin is regarded as the base of a new polymer in polyol construction.The present study aimed to investigate the effects of amine type(diethylenetriamine and ethylenediamine)on the modification of lignin-based polyols,so as to provide an alternative to petroleum polyols and,in turn,increase functional groups and reduce their harm to humans’health and the environment.To this aim,first,lignin was extracted from raw liquor.Next,the extracted lignin was reacted with diethylenetriamine(DETA)and ethylenediamine(EDA).Finally,the Mannich method was used for the reaction between amine lignin and propylene carbonate.The results of the Fourier Transform Infrared(FTIR)spectroscopy analysis showed that modification with DETA led to more structural change in lignin and peak 1100 indicates the presence of C–O bond related to urethane bonds in modified lignin.Moreover,adding propylene carbonate to aminated lignin did not result in much change in the results of the FTIR analysis.Additionally,urethane bonds can be seen in the results of GPC at 400℃–500℃.Furthermore,a slight decrease in thermal stability was observed in lignin modified with amine and propylene carbonate,compared to the raw lignin sample.

关键词： Polyol lignin diethylenetriamine ethylenediamine propylene carbonate polyurethanes NIPU

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

A fuzzy logic model to predict the out-of-seam dilution in longwall mining

引用

International Journal of Mining Science and Technology 2015年第1期25卷 91-98页

作者： ali Bahri najafi Mohammad ali Ebrahimi Farsangi Golam Reza Saeedi Mining Engineering Department Shahid Bahonar University of Kerman

The longwall mining method is often affected by the out-of-seam dilution(OSD). Therefore, predicting and controlling of dilution are important factors for reducing mining costs. In this study, the fuzzy set theory and multiple regression models with parameters, including variation in seam thickness, dip of seam, seam thickness, depth of seam, and hydraulic radius as inputs to the models were applied to predict the OSD in the longwall coal panels. Field data obtained from Kerman and Tabas coal mines, Iran were used to develop and validate the models. Three indices including coefficient of determination(R2), root mean square error(RMSE) and variance account for(VAF) were used to evaluate the performance of the models. With 10 randomly selected datasets, for the linear, polynomial, power, exponential,and fuzzy logic models, R2, RSME and VAF are equal to(0.85, 4.4, 84.4),(0.61, 7.5, 59.6),(0.84, 4.5, 72.7),(0.80, 4.1, 79.6), and(0.97, 2.1, 95.7), respectively. The obtained results indicate that the fuzzy logic model predictor with R2= 0.97, RMSE = 2.1, and VAF = 95.7 performs better than the other models.

关键词：模糊逻辑模型模型预测长壁开采稀释长壁采煤法多元回归模型煤层厚度模糊集理论

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

Microscopic and macroscopic atomization characteristics of a pressure-swirl atomizer, injecting a viscous fuel oil

引用

Chinese Journal of Chemical Engineering 2020年第1期28卷 9-22页

作者： Seyed Mohammad Ali Najafi Pouria Mikaniki Hojat Ghassemi School of Mechanical Engineering Iran University of Science and Technology(IUST)P.O.B.16765-163TehranIran

Combustion of heavy fuels is one of the main sources of greenhouse gases, particulate emissions, ashes, NOxand SOx. Gasification is an advanced and environmentally friendly process that generates combustible and clean gas products such as hydrogen. Some entrained flow gasifiers operate with Heavy Fuel Oil(HFO) feedstock. In this application, HFO atomization is very important in determining the performance and efficiency of the gasifiers.The atomization characteristics of HFO(Mazut) discharging from a pressure-swirl atomizer(PSA) are studied for different pressures difference(Δp) and temperatures in the atmospheric ambient. The investigated parameters include atomizer mass flow rate( _m), discharge coefficient(CD), spray cone angle(θ), breakup length(Lb), the unstable wavelength of undulations on the liquid sheet(λs), global and local SMD(sauter mean diameter) and size distribution of droplets. The characteristics of Mazut sheet breakup are deduced from the shadowgraph technique. The experiments on Mazut film breakup were compared with the predictions obtained from the liquid film breakup model. Validity of the theory for predicting maximum unstable wavelength was investigated for HFO(as a highly viscous liquid). A modification on the formulation of maximum unstable wavelength was presented for HFO. SMD decreases by getting far from the atomizer. The measurement for SMD and θ were compared with the available correlations. The comparisons of the available correlations with the measurements of SMD andθ show a good agreement for Ballester and Varde correlations, respectively. The results show that the experimental sizing data could be presented by Rosin-Rammler distributions very well at different pressure difference and temperatures.

关键词： Gasifier Heavy fuel oil Atomization Pressure-swirl atomizer Mazut Size distribution Wavelength Viscosity

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

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

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

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：