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: Adsorption,Methylene blue,activated carbon,aqueous solution,Oak fruit hull
- چکیده:
- چکیده انگلیسی: This study was conducted to assess the ability of the studied adsorbent, i.e. raw oak fruit hulls and the activated carbon prepared from oak fruit hull for removing the Methylene blue (MB) from aqueous solution. This study was conducted under various effective parameters, e.g., contact time, pH, MB concentration, adsorbent concentration. The optimum amount of each parameter was determined and the isotherm and kinetic studies were also carried out. The results revealed that the best results for MB removal efficiency are observed using the activated carbon prepared from oak fruit hulls. It was also observed that increasing the contact time, pH and adsorbent concentration provides better condition to enhance the dye removal efficiency and increasing the MB, hence reducing the removal efficiency. Furthermore, the results also clarified that the best models to describe the MB adsorption onto the raw oak fruit hulls and activated carbon are the Langmuir model 1 (R2=0.9971) and Langmuir 2 (R2=0.7631), respectively. In addition, the adsorption of MB onto the raw oak fruit hulls and activated carbon are better fitted to pseudo-second-order model and zero-order model, respectively. Finally, it can be concluded that the activated carbon prepared from the raw oak fruit hulls is more valuble than the raw oak fruit hull for removing the MB.
- انتشار مقاله: 02-10-1397
- نویسندگان: A. Seidmohammadi,G. Asgari,A. Dargahi,M. Leili,Y. Vaziri,B. Hayati,A.A. Shekarchi,A. Mobarakian,A. Bagheri,S. B. Nazari Khanghah,A. Keshavarzpour
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Solid Mechanics
- نوع مقاله: Journal Article
- کلمات کلیدی: Upper bound method,Velocity field,Axisymmetric extrusion
- چکیده:
- چکیده انگلیسی: In this paper, a generalized expression for the flow field in axisymmetric extrusion process is suggested to be valid for any dies and the boundary shapes of the plastic deformation zone. The general power terms are derived and the extrusion force is calculated by applying upper bound technique for a streamlined die shape and exponential functions for shear boundaries. It is shown that assuming exponential boundaries for deformation zone yields a die shape with smaller extrusion force than that of by assuming spherical shape boundaries is in agreement with the results obtained by the finite element method.
- انتشار مقاله: 06-05-1394
- نویسندگان: H Haghighat,G.R Asgari
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Mechanical Engineering Transactions of the ISME
- نوع مقاله: Journal Article
- کلمات کلیدی: upper bound,Extrusion,Bimetallic rod
- چکیده:
- چکیده انگلیسی: In this paper, an upper bound approach is used to analyze the extrusion process of bimetallic rods through arbitrarily curved dies. Based on a spherical velocity field, internal, shearing and frictional power terms are calculated. The developed upper bound solution is used for calculating the extrusion force for two types of die shapes: a conical die as a linear die profile and a streamlined die shape as a curved die profile. The bimetallic rod extrusion process is also simulated by using the finite element code, ABAQUS for those two die shapes. The analytical results have been compared with finite element data and the experimental results obtained from a reference to illustrate the validity of the proposed upper bound solution. These comparisons show a good agreement.
- انتشار مقاله: 12-11-1390
- نویسندگان: H. Haghighat,G. R. Asgari
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Engineering, Transactions A: Basics
- نوع مقاله: Journal Article
- کلمات کلیدی: p,chloropheno Ultrasound Nano Zero,valent Copper Persulfat Activation
- چکیده:
- چکیده انگلیسی: In this study, nanoscale zero-valent copper (nZVC) as catalyst activated persulfate (PS) was used for the degradation of p-chlorophenol (p-CP) under ultrasonic (US) irradiation in aqueous solution. The effect of different operational parameters such as solution pH (3.5-10.5), PS concentration (1-7.5 mm/L), nZVC dosage (5-35 mg/L) and initial p-CP concentration (10-100 mg/L) were evaluated at different contact time. Results indicated that US/PS/nZVC system achieve higher efficiency in p-CP degradation than US/PS, US/nZVC and PS/nZVC systems. The optimal p-CP removal efficiency (98%) was achieved within 40 min with 5 mm/L PS and 30mg/L nanocatalyst at 25 mg/L initial p-CP concentration. It was also observed that the p-CP degradation rate depends on initial p-CP concentrations. To clarify the mineralization of p-CP, TOC and COD were analyzed at optimum conditions. COD and TOC removal rate obtained from the US/PS/nZVC system with contact time of 60 min were 61and 75%, respectively. Through the use of methanol (MA) and tert-butyl alcohol (TBA) as radical scavengers, was identified as the main radical species that are generated during processes. The removal process of p-CP could be described by the pseudo-first-order kinetics. The apparent degradation rate constant (k) was 0.076 min-1 in US/PS/nZVC system at optimal conditions.
- انتشار مقاله: 02-11-1398
- نویسندگان: Z. Sharifi,G. Asgari,A. Seid-mohammadi
- مشاهده