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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: International Journal of Advanced Design and Manufacturing Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Adjoint problem,Conjugate gradient method,Time-dependent heat flux,Three layer system
- چکیده:
- چکیده انگلیسی: In this paper, the conjugate gradient method coupled with adjoint problem is used in order to solve the inverse heat conduction problem and estimation of the time- dependent heat flux using the temperature distribution at a point in a three layer system with none homogeneous boundary conditions. Also, the effect of noisy data on final solution is studied. For solving this problem the general coordinate method is used. The inverse heat conduction problem of estimating the transient heat flux, applied on part of the boundary of an irregular region is solved in this paper. The present formulation is general and can be applied to the solution of boundary inverse heat conduction problems over any region that can be mapped into a rectangle. The obtained results for few selected examples show the good accuracy of the presented method. Also the solutions have good stability even if the input data includes noise. Applications of this model are in the thermal protect systems (t.p.s.) and heat shield systems.
- انتشار مقاله: 09-10-1394
- نویسندگان: Mohammad Mohammadiun,Mohammad Mohammadiun,Mohammad Mohammadiun
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Advanced Studies in Humanities and Social Science
- نوع مقاله: Journal Article
- کلمات کلیدی: Performance,Organizational Commitment,human resource,Organizational Promotion,job involvement
- چکیده:
- چکیده انگلیسی: The present study investigates the effect and relationship between organizational promotion system and organizational commitment among the HRM staff of; thus, the main purpose of this paper is to determine the relation among the variables of employees’ job satisfaction or organizational commitment as well as providing scientific suggestions for improving the employees’ job satisfaction and as a result, increasing their organizational commitment. Hence, the present paper investigates the objectives such as relationship between the employees’ job promotion and satisfaction and their organizational commitment in human resource management and relationship between the employees’ satisfaction with salary and their organizational commitment.
- انتشار مقاله: 12-12-1397
- نویسندگان: Mohammad Reza Mohammadi,Mohammad Reza Mohammadi,Mohammad Reza Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Agricultural Science Research& Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Marketing,ICT,Agricultural Crops
- چکیده:
- چکیده انگلیسی: This research through comparison study of application of ICT on marketing of agricultural crops in khozestan province, evaluate the role of such factors. The study is of applied type and the method being used is descriptive- correlational. Statistical population of this research is all agricultural experts of Khuzestan province and using Cochran’s formula , a sample size of 144 members was selected census method is used for the purpose of responding to the questionnaires. Researches show that there is significant difference between item of electronic readiness based on gender at 1% and item of market relationship, supply and demand, reducing production and sale costs based on gender at 5% and also there is significant difference between item of market relationship based on attending at computer education courses at level of 5%. There is significant difference between market influence based on education at the level of 1% and market relation based on education of respondents at the level of 5%.
- انتشار مقاله: 03-10-1394
- نویسندگان: Mohamad Kamal Ebrahimi Filouri,Azita Zand,Mohammad Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Future of Medical Education Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Medical students,Academic Performance,Keywords: Gardner Intelligences
- چکیده:
- چکیده انگلیسی: Background: Gardner’s Multiple-Intelligences profile can serve as a powerful instrument for assessment of learners' abilities and aptitudes. The present study aimed to obtain the Gardner’s Multiple Intelligences profile of students of Tabriz University of Medical Sciences (TUOMS) in the academic year 2014-2015 and examine its relationship with their academic performance.
Methods: This cross-sectional descriptive-correlational study was conducted on medical, nursing and midwifery students of TUOMS in the academic year 2014-2015. Data was collected by administering Gardner’s Multiple Intelligences Developmental Assessment Scales to 150 subjects selected by non-probability convenience sampling. Academic performance of students was evaluated by their average grades. Data was analyzed by SPSS19 using multiple regression.
Results: Medical students scored highest in existential intelligence (18.42 ± 4.67) and intrapersonal intelligence (16.74 ± 4.15) and scored lowest in musical intelligence (12.54 ± 3.99) and bodily intelligence (13.66 ± 4.46). Regression analysis showed that verbal intelligence (P= 0.004, β = 0.392) and existential intelligence (P= 0.014, β = -0.327) were the only Gardner intelligence components that can explain the students' academic performance with statistical significance.
Conclusion: The results showed that among Gardner’s Multiple-Intelligences, existential, intrapersonal, interpersonal, and verbal intelligence contribute the most to the selection of medical sciences as the path of education, and that verbal intelligence is associated with academic success. The results of this study can be employed as an applied knowledge to improve the quality of education counseling to be provided for future medical students.- انتشار مقاله: 29-04-1396
- نویسندگان: Roghayeh Poursaberi,Mohammad Mehdi Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Interdisciplinary Journal of Virtual Learning in Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Elite,Brain circulation,Reverse migration,Diaspora,Shiraz University of Medical Sciences
- چکیده:
- چکیده انگلیسی: Background: Brain mobility is an alternative word for brain drain. Today, brain drain is considered as a major loss that has a very harmful effect on developing countries. The brain movement, and inverse immigration depends a lot on policies adopted in the countries of origin. This research was conducted with the aim of investigating the role of virtual networks and diaspora in elite brain mobility and circulation in Iran. Methods: This study was conducted using a mixed-method approach based on sequential exploratory strategy in 2018. In qualitative section a semi-structured interview was conducted with 19 former graduates who had returned back to Iran. The theoretical saturation was reached via a purposeful sampling and maximum variation by applying conventional content analysis method processes. In the quantitative section, a questionnaire was developed and its validity and reliability was tested and verified for data collection. The questionnaire was distributed among a random sample of 285 physicians out of a target population of 1100 physician returnees. Only 158 participated in the study by returning the completed questionnaire. In addition, the data were reviewed by applying descriptive-survey method, and content analysis was used to analyze the collected data. Results: Regarding the theme of inclusive elite brain mobility and circulation, the results are indicative of the existence of 18 basic themes, and 4 organizing themes including: cultural strategies, educational and research strategies, management strategies, social and economic strategies, and 1 global theme. The Basic Islamic Cultural Requirement theme (with a factor of 0.83, P<0.001) is the best descriptor for elite brain circulation and movement. Conclusion: Developing countries not only should send their elite medical graduates abroad to gain professional experiences, but also they should try to motivate them for inverse migration to their homeland by creating and promoting Diaspora networks.
- انتشار مقاله: 22-09-1378
- نویسندگان: Zahra Yazdani,Parviz Saketi,Fariba Karimi,Mohammad H Yarmohammadian
- مشاهده
- جایگاه : پژوهشی
- مجله: Current Medical Mycology
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,Microsporidia,Immunocompetent individuals,Immunocompromised patients
- چکیده:
- چکیده انگلیسی: Background and Purpose: Gastroenteritis and the clinical profile caused by Microsporidia, an opportunistic pathogen, may be severe in immunocompromised individuals, especially in AIDS patients. Conventionally, it is necessary to detect the small infective spores in stained smears. However, due to the limitations of the microscopy-based methods, several DNA-based methods such as polymerase chain reaction (PCR) have recently been developed to enhance diagnosis sensitivity. Therefore,we sought to evaluate the rate of infection in immunocompromised patients as compared with immunocompetent patients in Kerman, Iran.
Materials and Methods: We collected stool samples of 199 human subjects (116 males and 83 females), aged 1 to 69 years old. They were divided into immunocompromised (i.e., AIDS [n=72] and cancer-positive patients [n=59]) and immunocompetent (n=68) groups. We comparatively examined the fecal materials using the microscopy and PCR methods.
Results: The overall prevalence rate of Microsporidia infection was 10.05% (20/199). Entrocytozoon bieneusi was the only species within the Microsporidia genus that was identified in 14.5% (19/131) of the immunocompromised patients and 1.47% (1/68) of the immunocompetent individuals.
Conclusion: Considering the higher prevalence rate of microsporidiosis in patients with immunodeficiency (10.03%), we suggest performing sensitive and specific techniques such as PCR for the detection of these parasites in immunocompromised patients.- انتشار مقاله: 18-04-1398
- نویسندگان: Maryam Nooshadokht,Iraj Sharifi,Mohammad Ali Mohammadi,Majid Pirestani,Afgar Afgar,Armina Mahootchi,Samira Salari,Zahra Babaei
- مشاهده
- جایگاه : پژوهشی
- مجله: Energy Equipment and Systems
- نوع مقاله: Journal Article
- کلمات کلیدی: Methane,hydrogen,Micro tube,Step,Air,Reduced chemistry
- چکیده:
- چکیده انگلیسی: In this study, the effect of the levels of hydrogen addition to methane-air premixed flame in a micro-stepped reactor has been studied numerically. In addition, the effects of mixture velocity and walls’ thermal conductivity (Kw) on the flame’s location, temperature, and species distribution in a micro reactor were calculated using a 2D numerical laminar steady code. The results showed that an increasing level of hydrogen in the methane-air mixture probably improves the combustion process in a micro reactor by intensifying the flame speed, adiabatic flame temperature and the generation of some crucial species (such as OH, H, HCO, HO2, and H2O2). Further, it was found that the addition of hydrogen to methane can shift the flame towards the inlet. In this way, it probably guarantees the flame’s presence in certain conditions compared to cases of no hydrogen addition. In conclusion, it is shown that the temperature distribution along the axis and the wall of the micro reactor can be dependent on the amounts of hydrogen added to the methane-air mixture.
- انتشار مقاله: 01-02-1393
- نویسندگان: Mohammadreza Baigmohammadi,Sadegh Tabejamaat,Babak Kashir
- مشاهده
- جایگاه : پژوهشی
- مجله: Environmental Energy and Economic Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,Air pollution,Renewable Energies,Heat Pump,Residential Buildings
- چکیده:
- چکیده انگلیسی: The use of renewable energies, especially in metropolises has led to a reduction in environmental pollution and greater access to clean, renewable and sustainable energy. This paper evaluates the effectiveness of a national plan adopted by the Tehran city council for reducing air pollutions. This plan is designed to increase the share of renewable energies in residential buildings. This study assumes that the extended renewable share is supplied by ground source heat pump (GSHP) systems. The number of Residential Building Permits (RBPs) issued by the city government is predicted in the next five years. Then the effects of using GSHPs on the amount of consumed electricity power and Gas are estimated by considering the policies intended for using GSHPs in Tehran. Finally, the reduction amount of air pollutants is calculated by considering the obtained results from the previous step. The reduction in gas consumption is estimated to be 4,810,848 m3. As a result of this reduction, 9429 tons of CO2, 201 kg of SOx, and 10 tons of NOx are prevented from releasing into the atmosphere. The increased amount of electricity power from running GSHPs in the residential buildings is predicted to be 11,182,543 kWh. The natural gas consumption savings is nearly 50% regarding using combined cycle power plants to generate electricity. The results demonstrated that the plan leads to decrease the emission of CO2 and SOx, and increases in NOx emissions when the excess electricity is supplied by the steam turbine, gas turbine, and combined cycle power plants.
- انتشار مقاله: 02-03-1396
- نویسندگان: Hossein Yousefi,Younes Noorollahi,Mohammad Mohammadi,Pedram Bigdelou,Mahyar Taheri Bavil Oliaei
- مشاهده
- جایگاه : پژوهشی
- مجله: Civil Engineering Infrastructures Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Frequency,Artificial Neural Networks,Damage Identification,Manhattan Distance,Structures
- چکیده:
- چکیده انگلیسی: One of the numerous methods recently employed to study the health of structures is the identification of anomaly in data obtained for the condition of the structure, e.g. the frequencies for the structural modes, stress, strain, displacement, speed, and acceleration) which are obtained and stored by various sensors. The methods of identification applied for anomalies attempt to discover and recognize patterns governing data which run in sharp contrast to the statistical population. In the case of data obtained from sensors, data appearing in contrast to others, i.e. outliers, may signal the occurrence of damage in the structure. The present research aims to employ computer algorithms to identify structural defects based on data gathered by sensors indicating structural conditions. The present research investigates the performance of various methods including Artificial Neural Networks (ANN), Density-Based Spatial Clustering of Applications with Noise (DBSCAN), Manhattan Distance, Curve Fitting, and Box Plot in the identification of samples from damages in a case study using frequency values related to a cable-support bridge. Subsequent to the implementation of the methods in the datasets, it was shown that the ANN provided the optimal performance.
- انتشار مقاله: 19-02-1396
- نویسندگان: Mohammad Mohammadizadeh,Babak Yasi
- مشاهده
- جایگاه : پژوهشی
- مجله: Civil Engineering Infrastructures Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Damage detection,Axial Load,Characteristic Equation,Eigen Frequency,Notched Beam
- چکیده:
- چکیده انگلیسی: The present study utilizes an analytical method to formulate the three lowest modal frequencies of axially-loaded notched beam through both crack location and load level in a specific format that can be used in existing frequency-based crack-identification methods. The proposed formula provides a basis to shift into two states, one with axial loading and the other without any loading whatsoever. When any two natural frequencies in simply-supported beam with an open crack, subjected to axial load, are measured, crack position and extent can be determined, using a characteristic equation, which is a function of crack location, sectional flexibility, and eigenvalue (natural frequency). Theoretical results show high accuracy for service axial loads. In this range, errors for crack location and extent are less than 12% and 10%, respectively.
- انتشار مقاله: 04-05-1393
- نویسندگان: Omid Rezaifar,Mohammad Reza Doostmohammadi
- مشاهده