Search results for: Parvin Nikpoorparizi

Authors: Morteza Abbaszadeh, Parvin Nikpoorparizi, Mina Shahrooz

Abstract:

For the first time since 1940 and presentation of theodorson-s theory, distribution of thrust, torque and efficiency along the blade of a counter rotating propeller axial fan was studied with a novel method in this research. A constant chord, constant pitch symmetric fan was investigated with Reynolds Stress Turbulence method in this project and H.E.S. method was utilized to obtain distribution profiles from C.F.D. tests outcome. C.F.D. test results were validated by estimation from Playlic-s analytical method. Final results proved ability of H.E.S. method to obtain distribution profiles from C.F.D test results and demonstrated interesting facts about effects of solidity and differences between distributions in front and rear section.

Keywords: C.F.D Test, Counter Rotating Propeller, H.E.S. Method, R.S.M. Method

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Authors: Mohammad Ali Baradaran Ghahfarokhi, Parvin Baradaran Ghahfarokhi

Abstract:

In this paper, first we introduce the stable distribution, stable process and theirs characteristics. The a -stable distribution family has received great interest in the last decade due to its success in modeling data, which are too impulsive to be accommodated by the Gaussian distribution. In the second part, we propose major applications of alpha stable distribution in telecommunication, computer science such as network delays and signal processing and financial markets. At the end, we focus on using stable distribution to estimate measure of risk in stock markets and show simulated data with statistical softwares.

Keywords: stable distribution, SaS, infinite variance, heavy tail networks, VaR.

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Authors: Khosrow Maleknejad, Reza Mollapourasl, Parvin Torabi, Mahdiyeh Alizadeh,

Abstract:

Sinc-collocation scheme is one of the new techniques used in solving numerical problems involving integral equations. This method has been shown to be a powerful numerical tool for finding fast and accurate solutions. So, in this paper, some properties of the Sinc-collocation method required for our subsequent development are given and are utilized to reduce integral equation of the first kind to some algebraic equations. Then convergence with exponential rate is proved by a theorem to guarantee applicability of numerical technique. Finally, numerical examples are included to demonstrate the validity and applicability of the technique.

Keywords: Integral equation, Fredholm type, Collocation method, Sinc approximation.

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Authors: Elham Moniri, Homayon Ahmad Panahi, Ahmad Izadi, Mohamad Mehdi Parvin, Atyeh Rahimi

Abstract:

In this investigation Salicylic acid, Sulfosalicylic acid and Acetyl salicylic acid were chosen as a sample for thin layer chromatography (TLC) on silica gel plates. Bicarbonate buffer at different pH containing different amounts of boric acid was applied as mobile phase. Specific interaction of these substances with boric acid has effect on Rf in thin layer chromatography. Regular and similar trend was observed in variations of Rf for mentioned compounds in TLC by altering of percentages of boric acid in mobile phase in pH range of 8-10. Also effect of organic solvent, mixture of water/ organic solvent and organic solvent containing boric acid as mobile phase was studied.

Keywords: Thin layer chromatography (TLC), Aspirin, Salicylic acid, Sulfosalycylic acid, Boric acid.

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Authors: Maryam Azizkhani, Parvin Zandi

Abstract:

Application of synthetic antioxidants such as tertbutylhydroquinon (TBHQ), in spite of their efficiency, is questioned because of their possible carcinogenic effect. The purpose of this study was application of mixtures of natural antioxidants that provide the best oxidative stability for margarine. Antioxidant treatments included 10 various mixtures (F1- F10) containing 100-500ppm tocopherol mixture (Toc), 100-200ppm ascorbyl palmitate (AP), 100- 200ppm rosemary extract (Ros) and 1000ppm lecithin(Lec) along with a control or F0 (with no antioxidant) and F11 with 120ppm TBHQ. The effect of antioxidant mixtures on the stability of margarine samples during oven test (60°C), rancimat test at 110°C and storage at 4°C was evaluated. Final ranking of natural antioxidant mixtures was as follows: F2,F10>F5,F9>F8>F1,F3,F4>F6, F7. Considering the results of this research and ranking criteria, F2(200ppmAp + 200ppmRos) and F10(200ppmRos + 200ppmToc +1000ppmLec) were recommended as substitutes for TBHQ to maintain the quality and increase the shelf-life of margarine.

Keywords: Margarine, Natural antioxidant, Oxidative stability, Shelf-life.

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Authors: Mohammad Khosravi, Ali Kiani, Behroz Dastar, Parvin Showrang

Abstract:

Review was carried out on important anti-nutritional compounds of livestock and poultry foods and the effect of radiation usage. Nowadays, with advancement in technology, different methods have been considered for the optimum usage of nutrients in livestock and poultry foods. Steaming, extruding, pelleting, and the use of chemicals are the most common and popular methods in food processing. Use of radiation in food processing researches in the livestock and poultry industry is currently highly regarded. Ionizing (electrons, gamma) and non-ionizing beams (microwave and infrared) are the most useable rays in animal food processing. In recent researches, these beams have been used to remove and reduce the anti-nutritional factors and microbial contamination and improve the digestibility of nutrients in poultry and livestock food. The evidence presented will help researchers to recognize techniques of relevance to them. Simplification of some of these techniques, especially in developing countries, must be addressed so that they can be used more widely.

Keywords: Antitrypsin, gamma anti-nutritional components, phytic acid, radiation.

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Authors: Salma Parvin, M. A. Alim

Abstract:

The convective and radiative heat transfer performance and entropy generation on forced convection through a direct absorption solar collector (DASC) is investigated numerically. Four different fluids, including Cu-water nanofluid, Al₂O₃-waternanofluid, TiO₂-waternanofluid, and pure water are used as the working fluid. Entropy production has been taken into account in addition to the collector efficiency and heat transfer enhancement. Penalty finite element method with Galerkin’s weighted residual technique is used to solve the governing non-linear partial differential equations. Numerical simulations are performed for the variation of mass flow rate. The outcomes are presented in the form of isotherms, average output temperature, the average Nusselt number, collector efficiency, average entropy generation, and Bejan number. The results present that the rate of heat transfer and collector efficiency enhance significantly for raising the values of m up to a certain range.

Keywords: DASC, forced convection, mass flow rate, nanofluid.

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Authors: A. Dashti, M. Eskandari, L. Farahmand, P. Parvin, A. Jafargholi

Abstract:

Breast Cancer is one of the most considerable diseases in the United States and other countries and is the second leading cause of death in women. Common breast cancer treatments would lead to adverse side effects such as loss of hair, nausea, and weakness. These complications arise because these cancer treatments damage some healthy cells while eliminating the cancer cells. In an effort to address these complications, laser radiation was utilized and tested as a targeted cancer treatment for breast cancer. In this regard, tissue engineering approaches are being employed by using an electrospun scaffold in order to facilitate the growth of breast cancer cells. Polycaprolacton (PCL) was used as a material for scaffold fabricating because of its biocompatibility, biodegradability, and supporting cell growth. The specific breast cancer cells have the ability to create a three-dimensional cell cluster due to the spontaneous accumulation of cells in the porosity of the scaffold under some specific conditions. Therefore, we are looking for a higher density of porosity and larger pore size. Fibers showed uniform diameter distribution and final scaffold had optimum characteristics with approximately 40% porosity. The images were taken by SEM and the density and the size of the porosity were determined with the Image. After scaffold preparation, it has cross-linked by glutaraldehyde. Then, it has been washed with glycine and phosphate buffer saline (PBS), in order to neutralize the residual glutaraldehyde. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidefor (MTT) results have represented approximately 91.13% viability of the scaffolds for cancer cells. In order to create a cluster, Michigan Cancer Foundation-7 (MCF-7, breast cancer cell line) and Michigan Cancer Foundation-10A (MCF-10A, human mammary epithelial cell line) cells were cultured on the scaffold in 24 well plate for five days. Then, we have exposed the cluster to the laser diode 808 nm radiation to investigate the effect of laser on the tumor with different power and time. Under the same conditions, cancer cells lost their viability more than the healthy ones. In conclusion, laser therapy is a viable method to destroy the target cells and has a minimum effect on the healthy tissues and cells and it can improve the other method of cancer treatments limitations.

Keywords: Breast cancer, electrospun scaffold, polycaprolacton, laser diode, cancer treatment.

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