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匹配条件: “Mohammad Reza Zarbakhsh Bahri” ,找到相关结果约16659条。
Effects of stress management training and problem solving on quality of life and life expectancy among infertile women
Mohammad Reza Zarbakhsh Bahri,Zahra Shoa Hasani,Ziba Zahiri Sorori,Farideh amirsadat Hafshejani
Pajouhan Scientific Journal , 2013,
Abstract: Introduction: This study aims to evaluate the effectiveness of stress management training and problem-solving training on quality of life and life expectancy of infertile women was conducted.Material and Methods: The method of this study was experimental with pretest – posttest design with a control group. population of 400 infertile women who referred to infertility center in Rasht were randomized to 250 of them were selected and the quality of life and life expectancy of the study were the 45 members of the quality of life and life expectancy lower were more randomly in three groups of 15 people, including two experimental groups and one control group were replaced. Each experimental groups were trained for 10 sessions of 90 minutes, respectively, stress management and problem-solving. Upon completion of the training program, participants were assessed again.Results: The result of present study showed that there was a significant difference between the experimental groups and control group in the scores of quality of life and life expectancy (p<0.05) while there was no significant difference between 2 experimental groups in these scores (p>0.05).Conclusion: Stress management and problem solving training were effective on life expectancy and quality of life of infertile women but there was no significant difference between the effectiveness of these two methods on life expectancy and quality of life of infertile women.
The Comparison of Many Biological Characteristics, Economical Conditions, General Health(Mental), of Mothers with Low and Normal Birth Weight at Guilan Province
Mohammad Reza Zarbakhsh Bhari,Simin Hoseinian,Gholamali Afrooz,Heidarali Hooman
Payavard Salamat , 2012,
Abstract: Background and Aim: Low weight at birth is one of the main health indexes in evaluating pregnancy period care, and recognizing its related factors is very important. The aim of this study was a comparison of pregnancy age, height, the distance between two pregnancies, gaining weight during pregnancy, economical condition, nutrition, general health of the mothers with low and normal birth weight. Materials and Methods: The research method was casual-comparative conducted as field-work. From all newborns born since (Jan 2008 to Nov 2009) 168 low birth weight babies with their mother and 157 newborns with normal weight from 20 maternity center at Guilan province were randomly selected. Mothers filled general health questionnaire with the reliability of 0.82. The data were analyzed using SPSS Software. Results: There was a significant difference among mothers (case and control ) in terms of pregnancy age, height ,distance between two pregnancies, increasing weight during pregnancy, economical condition, nutrition condition and general health (mental), (p 0.01). Conclusion: Various factors affected newborns weight at birth. Therefore, decreasing the rate of low weight will be one of the main social health indexes requiring cooperation of counter- groups and different organizations such as the Ministry of Health and treatment, psychotherapy, counseling centers and radio/television.
Spatial Reactor Dynamics and Thermo Hydraulic Behavior Simulation of a Large AGR Nuclear Power Reactor in Response to a Reactivity Step Change Disturbance  [PDF]
Mohammad Reza Ansari, Reza Marzooghi
Energy and Power Engineering (EPE) , 2011, DOI: 10.4236/epe.2011.33047
Abstract: In this article, two-dimensional partial differential equations with time representation of nuclear power reactor kinetics are considered for spatial reactor dynamics and thermo hydraulic behavior analysis of a large thermal advanced gas cooled reactor (AGR) type used for nuclear power generation. The equations include the neutron flux equation and delayed neutron precursor concentration, together with taking into account the equations to represent the thermo hydraulic behavior of the fuel, coolant and moderator temperatures. These equations are solved numerically using the finite difference method. For time propagation, an implicit method is applied. The desired initial condition for the reactor to stay at stable critical condition is established by finding the correct value of reactivity. The reactivity disturbance effect in the reactor is studied for different cases and presented for high reactivity values. The model was developed for the analysis of a large AGR with 2000 MWe for future power generation. The results show that the model not only behaves stably but also predicts the results physically for all the various parameters.
Recurrent Polynomial Neural Networks for Enhancing Performance of GPS in Electric Systems  [PDF]
Mohammad Reza MOSAVI
Wireless Sensor Network (WSN) , 2009, DOI: 10.4236/wsn.2009.12015
Abstract: Global Positioning System (GPS) is a worldwide satellite system that provides navigation, positioning, and timing for both military and civilian applications. GPS based time reference provides inexpensive but highly-accurate timing and synchronization capability and meets requirements in power system fault location, monitoring, and control. In the present era of restructuring and modernization of electric power utilities, the applications of GIS/GPS technology in power industry are growing and covering several technical and man-agement activities. Because of GPS receiver’s error sources are time variant, it is necessary to remove the GPS measurement noise. This paper presents novel recurrent neural networks called the Recurrent Pi-Sigma Neural Network (RPSNN) and Recurrent Sigma-Pi Neural Network (RSPNN). The proposed NNs have been used as predictor in GPS receivers timing errors. The NNs were trained using the dynamic Back Propagation (BP) algorithm. The actual data collection was used to test the performance of the proposed NNs. The ex-perimental results obtained from a Coarse Acquisition (C/A)-code single-frequency GPS receiver strongly support the potential of the method using RPSNN to give high accurate timing. The GPS timing RMS error reduces from 200 to less than 40 nanoseconds.
Input power-mechanism relationship for ultrasonic Irradiation: Food and polymer applications  [PDF]
Mohammad Reza Kasaai
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.58A2003

Mechanisms for interactions between ultrasound waves and materials vary as a function of input power of ultrasound. The objectives of this study were to compare mode of actions for ultrasound waves at different input powers. This study also describes various effects of ultrasound on materials at different input powers with emphasize on food and polymer applications. At low power of ultrasound, the major mechanism is acoustic streaming and at a power above threshold value, the most possible one is acoustic cavitation. Low power of ultrasound is a powerful analytical technique to investigate on physico-chemical properties of both biological and non-biological materials. While at sufficiently high power, it generates shear forces that are able to create different effects. For each pair of medium-acoustic wave, two types of mechanisms, acoustic streaming and cavitation may be occurred simultaneously.

The Effects of Schwann and Bone Marrow Stromal Stem Cells on Sciatic Nerve Injury in Rat: A Comparison of Functional Recovery
Sam Zarbakhsh,Mehrdad Bakhtiyari,Abolfazl Faghihi,Mohammad Taghi Joghataei
Cell Journal , 2012,
Abstract: Objective: Transplantation of bone marrow stromal cells (BMSCs) or Schwann cells (SCs) can facilitate axonal regeneration in peripheral nerve injuries. The aim of this study was to compare the effects of transplantation of BMSCs and SCs on functional recovery after injury to the sciatic nerve in the rat.Materials and Methods:In this experimental research, adult male Wistar rats (n=24, 250-300 g) were used, BMSCs and SCs were cultured, and SCs were confirmed with anti S100 antibody. Rats were randomly divided into 3 groups (n=8 in each group): 1; control group: silicon tube filled with fibrin gel without the cells, 2; BMSCs group: silicon tube filled with fibrin gel seeded with BMSCs and 3; SCs group: silicon tube filled with fibrin gel seeded with SCs. The left sciatic nerve was exposed, a 10 mm segment removed, and a silicone tube interposed into this nerve gap. BMSCs and SCs were separately transplanted into the gap in the two experimental groups and were labeled with anti BrdU and DiI respectively. After 12 weeks electrophysiological and functional assessments were performed and analyzed by one-way analysis of variance (ANOVA).Results: Electrophysiological and functional assessments showed a significant differencebetween the experimental groups compared with the control group. Electrophysiologicalmeasures were significantly better in the SCs transplantation group compared with the BMSCs treatment group (p<0.05). Functional assessments showed no statistically significant difference between the BMSCs and SCs groups (p<0.05).Conclusion: Although both BMSCs and SCs have the potential to produce functional recovery after injury to the sciatic nerve in rats, electrophysiological evaluation confirmsthat the improvement after SCs transplantation is greater than that after BMSCstransplantation.
Modified Scherrer Equation to Estimate More Accurately Nano-Crystallite Size Using XRD  [PDF]
Ahmad Monshi, Mohammad Reza Foroughi, Mohammad Reza Monshi
World Journal of Nano Science and Engineering (WJNSE) , 2012, DOI: 10.4236/wjnse.2012.23020
Abstract: Scherrer Equation, L=Kλ/β.cosθ, was developed in 1918, to calculate the nano crystallite size (L) by XRD radiation of wavelength λ (nm) from measuring full width at half maximum of peaks (β) in radian located at any 2θ in the pattern. Shape factor of K can be 0.62 - 2.08 and is usually taken as about 0.89. But, if all of the peaks of a pattern are going to give a similar value of L, then β.cosθ must be identical. This means that for a typical 5nm crystallite size and λ Cukα1 = 0.15405 nm the peak at 2θ = 170° must be more than ten times wide with respect to the peak at 2θ = 10°, which is never observed. The purpose of modified Scherrer equation given in this paper is to provide a new approach to the kind of using Scherrer equation, so that a least squares technique can be applied to minimize the sources of errors. Modified Scherrer equation plots lnβ against ln(1/cosθ) and obtains the intercept of a least squares line regression, ln=Kλ/L, from which a single value of L is obtained through all of the available peaks. This novel technique is used for a natural Hydroxyapatite (HA) of bovine bone fired at 600°C, 700°C, 900°C and 1100°C from which nano crystallite sizes of 22.8, 35.5, 37.3 and 38.1 nm were respectively obtained and 900°C was selected for biomaterials purposes. These results show that modified Scherrer equation method is promising in nano materials applications and can distinguish between 37.3 and 38.1 nm by using the data from all of the available peaks.
Analysis and Design of New Active Quasi Circulator and Circulators
Reza Bahri;Abdolali Abdipour;Gholamreza Moradi
PIER , 2009, DOI: 10.2528/PIER09072501
Abstract: This paper introduces two new type active quasi circulators and three new type active circulators which use the out-of-phase power divider/combiner, symmetric/anti-symmetric couplers and generic unilateral amplifiers. The proposed circuits are full-symmetric and composed of conventional microwave devices. Analytical relations for active quasi circulator modules are described. These modules have many variations and can be used for very wide frequency range depending on the type of the employed unilateral amplifier, power divider/combiner and symmetric/anti-symmetric couplers. Based on the proposed configurations, analysis and design of n-port active circulators are presented. Also they can be used in MMICs as active quasi circulators, active circulators and in other high frequency applications.
A Direct Derivation of the Exact Fisher Information Matrix for Bivariate Bessel Distribution of Type I  [PDF]
Mohammad Reza Kazemi, Alireza Nematollahi
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.33043
Abstract: This paper deals with a direct derivation of Fisher’s information matrix for bivariate Bessel distribution of type I. Some tools for the numerical computation and some tabulations of the Fisher’s information matrix are provided.
Portfolio Selection under Condition of Variable Weights  [PDF]
Reza Keykhaei, Mohammad Taghi Jahandideh
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.330210
Abstract: In this paper we generalize the single-period Markowitz Mean-Variance portfolio selection problem. The Markowitz’s model requires that after choosing the number of each security which constructs the portfolio in the beginning of the investment period, these numbers remain constant during and at the end of the investment period. We drop this as-sump- tion and consider an investment model in which the number of each security can vary randomly during the in-vestment period. Indeed we consider a single-period investment with the property that the initial weight of each security is not equal to the final weight of that security. We redefine the notion of the rate of return of each security and show that the return of the investment in a cash account is not certain. We investigate some alternatives among risky securi-ties which acts similar to cash accounts. For this we introduce the notion of free security and relate free securities to a riskless se- curity.

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