Study of the 3He(α,γ)7Be and 3H(α,γ)7Li Reactions at Astrophysical Energies

H. Sadeghi,R. Ghasemi 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.11

We have studied the important astrophysical 3He(α,γ)7Be and 3H(α,γ)7Li reactions in the framework of a potential model. 3He(α,γ)7Be and 3H(α,γ)7Li processes are key reactions in both bigbang nucleosynthesis and the p-p chain of hydrogen-burning in stars. The stellar 3He(α,γ)7Be and 3H(α,γ)7Li reactions were analyzed at low energies on the basis of a direct radiative capture mechanism. The astrophysical S-factors near zero energy were calculated without using the effective expansion of the S-factor or the asymptotic wave functions. In this paper, 3He(α,γ)7Be and 3H(α,γ)7Li radiative capture reactions at very low energies are taken as a case study. Using the M3Y potential, we have calculated the astrophysical S-factors for the E1 transition. In comparison with other theoretical methods and available experimental data, excellent agreement is achieved for the astrophysical S-factors of these processes.

Effect of Punch Speed on the Formability Behavior of Austenitic Stainless Steel Type 304L

H. Fathi,E. Emadoddin,H. R. Mohammadian Semnani,B. Mohammad Sadeghi 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.3

The aim of the present study is to investigate the effect of punch speed on forming limit diagram (FLD) and the formability of austenitic stainless steel type 304L. Effect of strain rate on the height of dome is studied using the hemispherical punch test. Results of this study show that strain rate has significant effect on FLD in this material and high formability obtains at low strain rate. The safe area of FLD between major and minor strains is extended under low strain rate. It is seen that at low punch speed, failure and fracture occur at the pole region (top of the dome), whereas at higher forming rates, failure occurs close to the flange region. Modeling studies are also carried out using Ls-Dyna to know the region of high stress concentration and to predict the location of fracture. There is good agreement between simulation and experimental results.

Design and simulation of a blanket module with high efficiency cooling system of tokamak focused on DEMO reactor

Sadeghi, H.,Amrollahi, R.,Zare, M.,Fazelpour, S. Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.2

In this study, the neutronic calculation to obtain tritium breeding ratio (TBR) in a deuterium-tritium (D-T) fusion power reactor using Monte Carlo MCNPX is done. In addition, by using COMSOL software, an efficient cooling system is designed. In the proposed design, it is adequate to enrich up to 40% ⁶Li. Total tritium breeding ratio of 1.12 is achieved. The temperature of helium as coolant gas never exceed 687℃. As regards the tolerable temperature of beryllium (650℃), the design of blanket module is done in the way that beryllium temperature never exceed 600℃. The main feature of this design indicates the temperature of helium coolant is higher than other proposed models for blanket module, therefore power of electricity generation will increase.

The Bacillus subtilis and Lactic Acid Bacteria Probiotics Influences Intestinal Mucin Gene Expression, Histomorphology and Growth Performance in Broilers

Aliakbarpour, H.R.,Chamani, Mohammad,Rahimi, G.,Sadeghi, A.A.,Qujeq, D. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.9

The aim of the present study was to evaluate the effect of commercial monostrain and multistrain probiotics in diets on growth performance, intestinal morphology and mucin gene (MUC2) expression in broiler chicks. Three hundred seventy-eight 1-d-old male Arian broiler chicks were allocated in 3 experimental groups for 6 wk. The birds were fed on a corn-soybean based diet and depending on the addition were labeled as follows: control-unsupplemented (C), birds supplemented with Bacillus subtilis (BS) and lactic acid bacteria (LAB) based probiotics. Each treatment had 6 replicates of 21 broilers each. Treatment effects on body weight, feed intake, feed conversion ratio and biomarkers such as intestinal goblet cell density, villus length, villus width, and mucin gene expression were determined. Total feed intake did not differ significantly between control birds and those fed a diet with probiotics (p>0.05). However, significant differences in growth performance were found. Final body weight at 42 d of age was higher in birds fed a diet with probiotics compared to those fed a diet without probiotic (p<0.05). Inclusion of Bacillus subtilis based probiotic in the diets also significantly affected feed conversion rate (FCR) compared with control birds (p<0.05). No differences in growth performance were observed in birds fed different types of probiotic supplemented diets. Inclusion of lactic acid bacteria based probiotic in the diets significantly increased goblet cell number and villus length (p<0.05). Furthermore, diets with Bacillus subtilis based probiotics significantly increased gene expression (p<0.05), with higher intestinal MUC2 mRNA in birds fed diet with probiotics compared to those fed the control diet. In BS and LAB probiotic fed chicks, higher growth performance may be related to higher expression of the MUC2 gene in goblet cells and/or morphological change of small intestinal tract. The higher synthesis of the mucin gene after probiotic administration may positively affect bacterial interactions in the intestinal digestive tract, intestinal mucosal cell proliferation and consequently efficient nutrient absorption.

Mechanical properties and microstructural evaluation of AA1100 to AZ31 dissimilar friction stir welds

Azizieh, M.,Sadeghi Alavijeh, A.,Abbasi, M.,Balak, Z.,Kim, H.S. Elsevier Science Publishers 2016 Materials chemistry and physics Vol.170 No.-

In this paper, microstructure and mechanical properties of dissimilar friction stir welds of AA1100 and AZ31 were investigated to understand the effects of rotational and travel speed as well as pin position. The tensile results of welded samples revealed that the sound welds were formed when the stirring pin deviated from the centreline to the AZ31 side. The X-ray diffraction shows that Al<SUB>3</SUB>Mg<SUB>2</SUB> and Al<SUB>12</SUB>Mg<SUB>17</SUB> intermetallics formation occurs in the stir zone during the welding process. High hardness of these intermetallic phases increased the hardness of the stir zone to 110 Hv. The best tensile results were obtained in the sample processed in the range of 28-32 (rev/mm) rotational to travel speed ratio.

Effect of pillars on the mixing efficiency of a peristaltically-driven Bingham fluid within a closed channel: A LBM simulation

Z. Poursharifi,H. Asadi,K. Sadeghy 한국유변학회 2018 Korea-Australia rheology journal Vol.30 No.2

We have numerically studied the effect of a fluid’s yield stress on the performance of a peristaltic mixer reinforced by cylindrical pillars, typical of those used in microfluidic systems. A multiple-relaxation-time, Lattice Boltzmann code was used to investigate the effect of a fluid’s yield stress on mixing efficiency for a viscoplastic fluid obeying the bi-viscous model. A Lagrangian particle-tracking method called “boxcounting” has been utilized for evaluating the mixing performance of the channel through introducing a stirring index parameter. Numerical results indicate that for both Newtonian and Bingham fluids, wave amplitude is the most potent tool for controlling the mixing performance of the mixer. It is shown that while for Newtonian fluids the mixing index is dropped if the channel is equipped with circular pillars, for Bingham fluids pillars can play a slightly positive role in enhancing the mixing efficiency of the mixer, and this is particularly so when the confinement ratio is sufficiently large. A more dramatic increase in the mixing efficiency can be attained when only one of the membranes is vibrating (i.e., the asymmetric case).

Optimization of the forging of aerofoil blade using the finite element method and fuzzy-Pareto based genetic algorithm

V. Alimirzaloo,M. H. Sadeghi,F. R. Biglari 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.6

In this research non-isothermal forging process of an aerofoil blade was simulated using 3-dimentional finite element method. Then an optimization approach integrated with the finite element method has been applied to optimize the blade forging process. Preform shape and angular position of the die parting line were optimized in order to minimize the flash volume, strain non-uniformity and lateral forces generated during the forging operation. The optimization method includes the finite element approach and the response surface method for the formulation of the objective functions. Using the multi-objective genetic algorithm, Pareto front of global optimal solutions was generated. Then a fuzzy-based membership value assignment method was used to select the best compromise solution. The simulation of the blade forging process was verified by experimental test. Results show that the numerical results and experimental tests have a good agreement. Waste material and lateral forces generated during the forging operation is decreased with optimization method significantly. Therefore the proposed approach is an appropriate method for multi-objective optimization of the forging process of aerofoil blades.

Relationship between Spiritual Health and Quality of Life in Patients with Cancer

Mohebbifar, Rafat,Pakpour, Amir H,Nahvijou, Azin,Sadeghi, Atefeh Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16

As the essence of health in humans, spiritual health is a fundamental concept for discussing chronic diseases such as cancer and a major approach for improving quality of life in patients is through creating meaningfulness and purpose. The present descriptive analytical study was conducted to assess the relationship between spiritual health and quality of life in 210 patients with cancer admitted to the Cancer Institute of Iran, selected through convenience sampling in 2014. Data were collected using Spiritual Health Questionnaire and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ). Patients' performance was assessed through the Karnofsky Performance Status Indicator and their cognitive status through the Mini-Mental State Examination (MMSE). Data were analyzed in SPSS-16 using descriptive statistics and stepwise linear regression. The results obtained reported the mean and standard deviation of the patients' spiritual health scoreas $78.4{\pm}16.1$ and the mean and standard deviation of their quality of life score as $58.1{\pm}18.7$. The stepwise linear regression analysis confirmed a positive and significant relationship between spiritual health and quality of life in patients with cancer (${\beta}$=0.688 and r=0.00). The results of the study show that spiritual health should be more emphasized and reinforced as a factor involved in improving quality of life in patients with cancer. Designing care therapies and spiritual interventions is a priority in the treatment of these patients.

Evaluation of Die Chilling Effects during Forging of Nimonic-80A Superalloy

D. Shahriari,M.H. Sadeghi,A. Amiri,M. Cheraghzadeh 한국소성가공학회 2010 기타자료 Vol.2010 No.6

Nimonic-80A is a kind of nickel-based superalloys which is used in high temperature components of land gas turbines. In this paper, the influence of four design factors: die temperature, strain rate, friction coefficient and geometry size of ring sample over the variation of internal diameters (VID) and forging load (FL) was studied. It was done by means of design methodology based on DOE-designated full factorial and FE simulations. FEM and experimental results showed that the variation of internal diameters and forging load had inverse proportion to the die temperature. Regression models were developed by using the response surface methodology (RSM) for VID and FL. Rate of the dynamic recrystallization varied depending on different amounts of die temperature. The results can be used in the semi-isothermal forging of complex part of the Nimonic-80A.

Enhancement of the gas separation properties of polyurethane membrane by epoxy nanoparticles

Ali Pournaghshband Isfahani,Morteza Sadeghi,Amir H. Saeedi Dehaghani,M. Ali Aravand 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.44 No.-

In this study, we report highly selective CO2 polyurethane incorporated with cured epoxy nanoparticles. PU–epoxy composite membranes were prepared via solution casting method. The obtained SEMmicrographs confirmed the nano-scale distribution of epoxy particles in the polymer matrix. DSC andFTIR spectra showed different phase separation for the PU composites compared to the pure PU. Theeffect of epoxy nanoparticles on the gas permeability of CO2, CH4, O2 and N2 was studied at 25 8C and10 bar. The selectivity of CO2/N2 increased from 25 for the pure PU membrane to 55.5 for the PU–EP10,while the CO2 permeability was unchanged.