در هنگام جستجو کلمه در قسمت عنوان میتوانید کلمات مورد جستجو را با کاراکتر (-) جدا کنید.
کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Progress in Color, Colorants and Coatings
- نوع مقاله: Journal Article
- کلمات کلیدی: Sonication,morphology,Rheology,Aspect ratio,glass flake,Epoxy Vinyl Ester
- چکیده:
- چکیده انگلیسی: In the present work, attempts were made to investigate the reinforcement and treatment effect of GF on morphological and rheological behaviour of GF/epoxy vinyl ester composites. GF was incorporated into epoxy vinyl ester resin by sonication, and mechanical agitation. Rheological and morphological properties were studied as a function of particle treatment and size distributions. The dispersion morphology, agglomeration degree and homogeneity of additives were analyzed by scanning electron microscopy SEM, and optical microscopy. Effect of mixing method, surface treatment, and particle size distribution on rheological properties of composites were investigated with a modular compact rheometer. The results showed that the mechanical agitation decreases GF aspect ratio more than sonication. SEM fractography shows finer particles improve toughness properties of the composites in comparison with larger ones. GF with larger circular diameter and length is more sensitive to shear than the smaller one. Rheological investigations showed that surface treatment improves the interaction between the polymer matrix and GF. These results indicated that the finer the GF, the better the rheological properties will be displayed.
- انتشار مقاله: 11-10-1348
- نویسندگان: A. Ghadami,M. Ehsani,H. Haddadi,B. Kaffashi
- مشاهده
- جایگاه : پژوهشی
- مجله: Progress in Color, Colorants and Coatings
- نوع مقاله: Journal Article
- کلمات کلیدی: Optical properties,Spectrophotometry,polyethylene blend,CIELAB color coordinates
- چکیده:
- چکیده انگلیسی: This study reports an application of instrumental color measurement for quantifying and comparing the optical properties of high density polyethylene HDPE and low density polyethylene LDPE blend films and the effect of blending ratio and miscibility on these properties. The technique of spectrophotometry in transmission and reflectance modes can be used as a versatile tool to evaluate the colorimetric parameters of polymers. The optical properties of the films indicated likeliness of affecting color spectrum by incorporating low-density PE LDPE into high-density PE HDPE. This is the principal reason for changing colorimetric parameters of the films. CIE colorimetric values in CIELab and CIELCho color scales and associated parameter Color Intensity CI showed that they are practical for comparing the blend films. The most change in the values versus composition was pertained to films of HDPE-rich blends which were verified miscible using thermal analysis. In this paper it was observed that the used measurement technique, through quantitative parameters provided by it, would be useful to reveal the difference in behavior of the HDPE/LDPE blends at miscible compositions from immiscible ones.
- انتشار مقاله: 11-10-1348
- نویسندگان: M. Mohammadi,A. A. Yousefi,M. Ehsani
- مشاهده
- جایگاه : پژوهشی
- مجله: SCIENTIA IRANICA
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی:
- انتشار مقاله: 26-02-1386
- نویسندگان: M. Ehsan,M. Ehsan,M. Ehsan
- مشاهده
- جایگاه : پژوهشی
- مجله: SCIENTIA IRANICA
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی:
- انتشار مقاله: 03-04-1386
- نویسندگان: M. Ehsan,M. Ehsan,M. Ehsan
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Operation and Automation in Power Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Demand response,Microgrid,Economic dispatch,Multi Carrier System,Small-scale Energy Resource
- چکیده: در این مقاله شبکه های توزیع آینده که شامل چند حامل انرژی میباشند به عنوان مفهوم یک ریز با شبکه چند حامل انرژی (MCMG) مورد بررسی قرار گرفته میشود. یکی از مسائل مهم در بهره برداری از این ریز شبکه ها، استفاده بهینه از حامل های مختلف انرژی می باشد. بطوری که، علاوه بر کاهش هزینه مصرف انرژی، امکان تولید برق و حرارت و فروش آنها نیز در نظر گرفته شود.
در مقاله مدل ارائه شده بهره برداری همزمان از حاملهای انرژی در یک ریزشبکه به همراه تجهیزات موجود در این ریزشبکه با فرض وجود مدیریت متمرکز پاسخگویی بار (IDSM) در قالب یک مساله بهینه سازی مد نظر قرار داده میشود. در مطالعات متداول در بهره برداری از چند حامل انرژی، هر حامل انرژی بطور جداگانه مورد بررسی قرار میگیرد. لذا اثر بهره برداری از حاملهای مختلف بر روی همدیگر نادیده گرفته میشود. در مدل ارائه شده با توجه به در نظر گرفتن کفایت ظرفیت خطوط انتقال حاملهای انرژی، ریز شبکه را در قالب یک سیستم یکپارچه انرژی(EH) با امکان بهره برداری بهینه حاملهای انرژی و فروش برق و حرارت برای شبکه در نظر گرفته می شود و اثر حاملهای مختلف انرژی بر روی همدیگر مدل شده است. شبیه سازی در یک ریز شبکه نمونه نشان میدهد که بهره برداری همزمان از چند حامل انرژی در یک ریز شبکه انعطاف پذیری عملکرد بهره برداری را افزایش داده و در نتیجه هزینه بهره برداری و تامین بارهای الکتریکی و حرارتی را کاهش میدهد. این مسأله به روش بهینه سازی تحلیلی مسائل MINLP به کمک نرم افزار GAMS حل شده است .- چکیده انگلیسی: : In this paper, the operation of a future distribution network is discussed under the assumption of a multi-carrier microgrid (MCMG) concept. The new model considers a modern energy management technique in electricity and natural gas networks based on a novel demand side management (DSM) which the energy tariff for responsive loads are correlated to the energy input of the network and changes instantly. The economic operation of MCMG is formulated as an optimization problem. In conventional studies, energy consumption is optimized from the perspective of each infrastructure user without considering the interactions. Here, the interaction of energy system infrastructures is considered in the presence of energy storage systems (ESSs), small-scale energy resources (SSERs) and responsive loads. Simulations are performed using MCMG which consists of micro combined heat and power (CHP), photovoltaic (PV) arrays, energy storage systems (ESSs), and electrical and heat loads in grid-connected mode. Results show that the simultaneous operation of various energy carriers leads to a better MCMG performance. Moreover, it has been indicated that energy sales by multi sources to main grids can undoubtedly reduce the total operation cost of future networks.
- انتشار مقاله: 17-10-1395
- نویسندگان: V. Amir,Sh. Jadid,M. Ehsan
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Operation and Automation in Power Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Demand response,Microgrid,Economic dispatch,Multi Carrier System,Small-scale Energy Resource
- چکیده: در این مقاله شبکه های توزیع آینده که شامل چند حامل انرژی میباشند به عنوان مفهوم یک ریز با شبکه چند حامل انرژی (MCMG) مورد بررسی قرار گرفته میشود. یکی از مسائل مهم در بهره برداری از این ریز شبکه ها، استفاده بهینه از حامل های مختلف انرژی می باشد. بطوری که، علاوه بر کاهش هزینه مصرف انرژی، امکان تولید برق و حرارت و فروش آنها نیز در نظر گرفته شود.
در مقاله مدل ارائه شده بهره برداری همزمان از حاملهای انرژی در یک ریزشبکه به همراه تجهیزات موجود در این ریزشبکه با فرض وجود مدیریت متمرکز پاسخگویی بار (IDSM) در قالب یک مساله بهینه سازی مد نظر قرار داده میشود. در مطالعات متداول در بهره برداری از چند حامل انرژی، هر حامل انرژی بطور جداگانه مورد بررسی قرار میگیرد. لذا اثر بهره برداری از حاملهای مختلف بر روی همدیگر نادیده گرفته میشود. در مدل ارائه شده با توجه به در نظر گرفتن کفایت ظرفیت خطوط انتقال حاملهای انرژی، ریز شبکه را در قالب یک سیستم یکپارچه انرژی(EH) با امکان بهره برداری بهینه حاملهای انرژی و فروش برق و حرارت برای شبکه در نظر گرفته می شود و اثر حاملهای مختلف انرژی بر روی همدیگر مدل شده است. شبیه سازی در یک ریز شبکه نمونه نشان میدهد که بهره برداری همزمان از چند حامل انرژی در یک ریز شبکه انعطاف پذیری عملکرد بهره برداری را افزایش داده و در نتیجه هزینه بهره برداری و تامین بارهای الکتریکی و حرارتی را کاهش میدهد. این مسأله به روش بهینه سازی تحلیلی مسائل MINLP به کمک نرم افزار GAMS حل شده است .- چکیده انگلیسی: : In this paper, the operation of a future distribution network is discussed under the assumption of a multi-carrier microgrid (MCMG) concept. The new model considers a modern energy management technique in electricity and natural gas networks based on a novel demand side management (DSM) which the energy tariff for responsive loads are correlated to the energy input of the network and changes instantly. The economic operation of MCMG is formulated as an optimization problem. In conventional studies, energy consumption is optimized from the perspective of each infrastructure user without considering the interactions. Here, the interaction of energy system infrastructures is considered in the presence of energy storage systems (ESSs), small-scale energy resources (SSERs) and responsive loads. Simulations are performed using MCMG which consists of micro combined heat and power (CHP), photovoltaic (PV) arrays, energy storage systems (ESSs), and electrical and heat loads in grid-connected mode. Results show that the simultaneous operation of various energy carriers leads to a better MCMG performance. Moreover, it has been indicated that energy sales by multi sources to main grids can undoubtedly reduce the total operation cost of future networks.
- انتشار مقاله: 17-10-1395
- نویسندگان: V. Amir,Sh. Jadid,M. Ehsan
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Mining and Environment
- نوع مقاله: Journal Article
- کلمات کلیدی: Clay Minerals,Tailing Storage Facility,Initial Settled Density,Shrinkage Limit Density,Beach Slope
- چکیده:
- چکیده انگلیسی: Changes in the tailing properties (increasing clay mineral content and fine particles) and poor operation of the dewatering systems have negative impacts on the Tailing Storage Facilities (TSF) of the Shahrbabak copper complex. The design solid concentration of the thickened tailings is 63 wt.% in the Shahrbabak paste plant but it is well below the design value right now (approx. 55 wt.%). The aim of this work is to find the effects of the clay mineral and dewatering operations on the water recovery and tailing dam capacity. The understudied samples were taken from the thickener underflow and prepared at the required solid concentrations (55, 60, 65, and 70 wt.%). The results obtained showed that the initial settled density varied from 1.044 to 1.146 t/m3 by increasing the solid concentrations from 55 to 63 wt.%. Furthermore, the shrinkage limit density of the two solid concentrations was recorded at 1.52 and 1.62 t/m3, and the crack volume was estimated at 6.3% and 7.2% of the final sample volume. Also the sub-aerial tailing beach slope in the upper quarter and the remainder of TSF was too low and exhibited 2.0% and 1.0%, respectively. However, it is far from the design values (3.5%, 2.5%, and 1.7% from head of the beach to the end). Thus it is clear that the clay minerals and fine particles hold more water in their inner network and occupy a more TSF volume. Nevertheless, the beach slope can be increased by improving the thickener performance and removing the leakage and other periodic water, although it seems impractical to achieve the design value due to the changes in the tailing properties.
- انتشار مقاله: 23-03-1397
- نویسندگان: Seyedeh M. Ehsani,M. Unesi,R. Tamartash
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Food Biosciences and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Structural Properties,Atomic force microscopy (AFM),Heat-Induced Whey Protein Isolate Gels,pH Modifications,Textural Analysis
- چکیده:
- چکیده انگلیسی: Formation and structure of whey protein heat-induced gels (100 mg mL-1) through heat treatment at 80 °C and pH modifications at three pH values of acidic (2), isoelectric (5.6) and neutral (7) were studied. The obtained results indicated that the nature of the primary gel networks was different at each pH value. The heat-induced gels produced at pH of 2 and 7, had acceptable overall shape and consistency which confirmed the significant effect of pH on the regular gel structures. Conversely, the amorphous gel structure was observed at isoelectric pH. According to Atomic Force Microscopy images, the structural unfolding of the protein during denaturation and formation of the fibrillar structures was observed in gel at pH of 2 and stranded aggregates at pH of 7. In terms of textural analysis, in samples at pH of 2 and 7, the required force to fracture gel structure was approximately equal and less than that of the sample at pH of 5.6 which goes back to the amorphous large protein aggregates in gel network at isoelectric pH. The ordered, regular and stable gel structures and high ionic balance were reflected in color parameters and lower amounts of moisture content in the gel matrix of samples at pH of 2 and 7 (P<0.05). The well-organized structure and stable gels network along with their desirable functional characteristics, might reinforce their application as food ingredients in terms of improving the qualitative and textural qualities of food products. This property can facilitate the use of these protein gels in novel food systems.
- انتشار مقاله: 25-09-1398
- نویسندگان: F. Farrokhi,M.R. Ehsani,F. Badii,M. Hashemi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Food Biosciences and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Lactobacillus acidophilus,Lactobacillus casei,Inulin,Synbiotic,Sweet Cream
- چکیده:
- چکیده انگلیسی: The effect of different levels of inulin (0, 1.5 and 3 %) and probiotic bacteria including Lactobacillus acidophilus and Lactobacillus casei on chemical properties (pH and titratable acidity) and viable count of probiotic strain of sweet cream during 30 days for 15-day interval at 4°C were studied. All experiments were carried out in three replications. The results showed that during the refrigeration storage of samples, pH decreased and acidity increased significantly. The addition of inulin caused significant changes in pH, acidity and the viability of probiotic strains. By increasing the level of inulin to 3%, the pH of the cream samples decreased, and the acidity and counts of the probiotics increased significantly and this was more significant in Lactobacillus acidophilus, although the treatment containing Lactobacillus acidophilus had the highest acidity. The probiotic survival evaluation also indicated that inulin treatment at 3% level was the best treatment for increasing the viability of the probiotics in cream. The results showed that the addition of prebiotics, such as inulin, could play an important role in increasing the viability of probiotics. In general, changes in the chemical properties of sweet cream during the refrigeration were standard, which could be considered as a synbiotic product and sweet cream as a dairy product can also be considered as a good carrier for probiotic bacteria.
- انتشار مقاله: 21-08-1397
- نویسندگان: A. Farrokh,M. R. Ehsani,N. Moayednia,R. Azizi Nezhad
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Food Biosciences and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Ultrafiltration,Milk,Protein,Permeate,Rejection Coefficient,Retentate
- چکیده:
- چکیده انگلیسی: The most widespread method applied for standardization of milk protein in cheese production is
ultrafiltration. In the current study, pasteurized, unhomogenized whole milk was ultrafiltered with APV
ultrafiltration system, 51 spiral wound, polysulfone membrane with 20000 Da molecular weight cut off (DDS,
Nakskov, Denmark) at 50 ˚C, such that the pressure difference between the two sides of membranes was not
more than 3.6 bar. Permeate that was collected, contained (w/w٪) 0.01 ٪ proteins. The protein was isolated from
crystalline TCA to the concentration of 12.5٪ (w/v), and then characterized by discontinuous SDS-PAGE (10-20
٪ acryleamide). The products of proteolysis contained α-lactalbumin (49.95±2.25 %), β- lactoglubolin
(22.30±2.3 %) and casein proteolysis products (30±4 %) and (96.68±1.725), (99.18±0.46) and (98.39±1.005) %
were rejected by ultrafiltration membrane, respectively. Casein micelles were rejected completely (100 ٪),
therefore, they couldn’t penetrate to permeate from retentate. Incomplete rejection of casein and penetration of
casein into permeate indicates the leakage of retentate in to permeate.- انتشار مقاله: 08-03-1397
- نویسندگان: M. Jahadi,M. R. Ehsani,S. Paidari
- مشاهده