مقالههای Reza Ahmadi
توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقالههای نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده میشوند.
اطلاعات انتشار: ششمین کنگره بین المللی مهندسی شیمی، سال ۱۳۸۸
تعداد صفحات: ۷
Perovskite–type Ba0.5Sr0.5Co0.2Fe0.8O3–δ oxide membranes were synthesized successfully using EDTNAD complexing method. The structure of Ba0.5Sr0.5Co0.2Fe0.8O3–δ was determined by XRD which showed a cubic perovskite structure. Oxygen permeation through these membranes was studied by the GC method using a high–temperature permeation cell. High permeation fluxes were observed. The permeation flux of Ba0.5Sr0.5Co0.2Fe0.8O3–δ membrane reached about 1.8 mlmin−1 cm−2 under air\He gradients at 950oC. The oxygen permeation flux was determined at different oxygen partial pressures of upstream and different temperatures between 750 and 950oC. The effects of air flow rate and sweeping helium flow rate on the oxygen permeation were also investigated. XRD pattern after O2 –TPD showed that Ba0.5Sr0.5Co0.2Fe0.8O3–δ possess a very stable structure.<\div>
اطلاعات انتشار: چهاردهمین همایش بین المللی نفت، گاز و پتروشیمی، سال ۱۳۸۹
تعداد صفحات: ۷
In iran and the other petroleum and gas enriching countries . A considerable amount of gas is combusted wastefully without using them profitably . Now a day while the world petroleum resources are diminishing incrasingly instead nes sources of gas are explored at a large amoun.therefore it is valuable commit investigation on gas conversion to the value–added product such as ethylene which is the most important raw material in petrochemical industry . the results from reactor tests shoewed that perovskite–type catalysts , can be used in this reation. for example , by varying the parameteresof the reactor their crystalline structures remain unchanged. in this paper the variation of temperature, flow rate, inert gas composition in feed and CH4\O2 have been studied for this reaction, and finally, the best catalyst have been selected among the prepared catalyst with perovskite structures.<\div>
۳Numerical Analysis of Effects of Input–parameters on the Flushing Efficiency of Plasma Channel in EDM process
اطلاعات انتشار: دوازدهمین کنفرانس ملی مهندسی ساخت و تولید ایران، سال ۱۳۹۰
تعداد صفحات: ۶
In the present study, the temperature distribution in the surface of workpiece during a single discharge has been simulated using ABAQUS code finite element software. The temperature dependency of material properties and the expanding of plasma channel radius by time have been employed in the simulation stage. The profile of temperature distribution has been utilized to calculate the dimensions of discharge crater. Based on the results of FEM and the experimental observations a numerical analysis has been developed assessing the contribution of input–parameters on the efficiency of plasma channel in removing the molten material from molten puddle on the workpiece at the end of each discharge in the EDM process. The results showed that plasma flushing efficiency increase as the pulse current increases, but decreases as the pulse on–time increases.<\div>
۴A Study of Unified Theory of Acceptance and the Use of Technology in Iranian Organization Case of Cement Factories
اطلاعات انتشار: کنفرانس جهانی افق های نوین در علوم انسانی، آینده پژوهی و توانمند سازی، سال ۱۳۹۴
تعداد صفحات: ۱۶
Study of Information Technology (IT) adoption models indicates that many competitive models have been presented and each one holds various sets of determinant factors. This research studies user acceptance model in Iran through applying Venkatesh et al.s’ the Unified Theory of Acceptance and Use of Technology (2003) which is outcome of integral structures related to the eight widely applied models in the area of technology adoption. This study is conducted in the first half of 2014. Data were collected from a sample consisting of directors and experts of four cement complexes in Qeshm, Ardestan, Darab and Kerman in Iran. The data analysis revealed that Effort Expectancy and Social Influence have a significant correlation with the Users Intentions of using technologies. In addition, it is found that there is a significant correlation between Facilitating Conditions and use Behavior. Furthermore, results demonstrated relationship between Performance Expectancy and Behavioral Intention which is stronger for men rather than women. Effort Expectancy and Social Influence as well as behavioral Intention is stronger for women in comparison with men. However, the relationship between Performance Expectancy variable with Behavioral Intention was not approved. Generally the result of this study shows that the UTAUT is a reliable and strong model for anticipating the Behavioral intention and Use behavior in IT systems adoption in Iran too.<\div>
۵The Relationship between Religious Attitudes and Psychological Well–being of Nurses Working in Health Centers in Qom University of Medical Sciences in 2014
اطلاعات انتشار: Health، دوم،شماره۴، ۲۰۱۶، سال ۰
تعداد صفحات: ۷
Background and Objectives: Nurses are the most important group who provide health system services. They may face with various stresses related to their job that may cause physiological problems. Many factors can influence their psychological health. With this in mind, the current study aimed to examine the relationship between religious attitude with psychological well–being in nurses working in Qom University of Medical Sciences. Methods: The data were collected by means of three questionnaires: demographic, psychological wellbeing, and religious attitude questionnaires. The religious attitude was assessed by Clark and Stark's religious attitude questionnaire. And the psychological well–being was measured by psychological well–being questionnaire introduced by Ryff and Keyes for adults in this study.Results: Religious attitude and psychological well–being were at medium level in 53\6% of the subjects (n=127). Correlational Pearson test showed that total score of religious attitude had significantly positive relationships with psychological well–being (r=+0\30, p0\01). Conclusion: Based on the results of the study, it can be concluded that religious attitude can have a positive influence on psychological well–being.
۶An Investigation of the Relationship between Religious Orientation and Quality of Life of Male Addicts Referring to Addiction Treatment Centers in Qom
اطلاعات انتشار: Health، دوم،شماره۴، ۲۰۱۶، سال ۰
تعداد صفحات: ۶
Background and Objectives: Addicts are among the socially disadvantaged people whose quality of life has been changed and damaged due to drug abuse. This in turn has influenced their physical, psychological and social health. Addiction is a phenomenon that has long existed in different human societies; and now again, it is still expanding despite the scientific advances and indisputable increase in people’s level of understanding and awareness. As such, this study aimed to examine the relationship between religious orientation and quality of life of the addicts.Methods: This is a descriptive–correlational study in which Alport religious orientation questionnaire and SF–12 quality of life questionnaire were used for data collection and analysis. The population consisted of the addicted men who had referred to 8 drug treatment centers in the city of Qom in 2013–14, out of whom 190 subjects were selected. The data were analyzed using SPSS software and correlation coefficient test. Results: The findings showed that there was a significant relationship between religious orientation and quality of life of addicts (p0\05).Conclusion: The findings suggest that external religious orientation in people being treated from the drug addiction can be used as a defense and supporting mechanism to improve the quality of life in them. Therefore, the likelihood of successful treatment will be increased by strengthening the external religious orientation.
۷Proposing New Methods to Enhance the Low–Resolution Simulated GPR Responses in the Frequency and Wavelet Domains
اطلاعات انتشار: International Journal of Mining & Geo-Engineering، چهل و هشتم،شماره۲، ۲۰۱۴، سال ۰
تعداد صفحات: ۱۴
To date, a number of numerical methods, including the popular Finite–Difference Time Domain (FDTD) technique, have been proposed to simulate Ground–Penetrating Radar (GPR) responses. Despite having a number of advantages, the finite–difference method also has pitfalls such as being very time consuming in simulating the most common case of media with high dielectric permittivity, causing the forward modelling process to be very long lasting, even with modern high–speed computers. In the present study the well–known hyperbolic pattern response of horizontal cylinders, usually found in GPR B–Scan images, is used as a basic model to examine the possibility of reducing the forward modelling execution time. In general, the simulated GPR traces of common reflected objects are time shifted, as with the Normal Moveout (NMO) traces encountered in seismic reflection responses. This suggests the application of Fourier transform to the GPR traces, employing the time–shifting property of the transformation to interpolate the traces between the adjusted traces in the frequency domain (FD). Therefore, in the present study two post–processing algorithms have been adopted to increase the speed of forward modelling while maintaining the required precision. The first approach is based on linear interpolation in the Fourier domain, resulting in increasing lateral trace–to–trace interval of appropriate sampling frequency of the signal, preventing any aliasing. In the second approach, a super–resolution algorithm based on 2D–wavelet transform is developed to increase both vertical and horizontal resolution of the GPR B–Scan images through preserving scale and shape of hidden hyperbola features. Through comparing outputs from both methods with the corresponding actual high–resolution forward response, it is shown that both approaches can perform satisfactorily, although the wavelet–based approach outperforms the frequency–domain approach noticeably, both in amplitude and shape of the outputted hyperbola response.
نمایش نتایج ۱ تا ۷ از میان ۷ نتیجه