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Showing 12 results for aghazadeh
Volume 7, Issue 3 (10-2007)
Abstract
Competitiveness is considered as a key criterion for appraising the degree of success for countries, industries and enterprises in the political, economic and commercial competition areas. Research findings show that competitiveness has been discussed in three levels of national, industry and enterprise (organization or company). Among all these levels, the enterprise level seems to be more considerable. In this study enterprise competitiveness has been viewed from two main perspectives: construct and behavioral. According to construct perspective, competitiveness includes two groups of factors which are composing and affecting factors. Based on behavioral perspective an enterprise faces two types of factors in its decisions and actions which are strategic and operational ones. As a result of literature review, summarization and complementary edition, totally 28 factors have been identified as competitiveness factors ({16 composing f. and 12 affecting f.} and {15 strategic f. and 13 operational f.}). A questionnaire has also been developed based on these factors. The findings show that in Iranian business context, all competitiveness factors of enterprises are highly important but very weak
Volume 10, Issue 1 (5-2010)
Abstract
This study aims to develop a native scale of competitiveness in Iran's commercial banks. Based on the review of theoretical and empirical literatures, a comprehensive competitiveness scale is developed to show the various dimensions of international performance of commercial banks. The validity of the scale is confirmed by 50 experts. The information of the scale is collected using a sample of 300 questionnaires distributed among officers of commercial banks working at international departments of Iran's commercial banks. The main findings of this study can be summarized as follows. 1. The main determinants of native scale for measuring the performance of international departments of commercial banks are financial and non-financial performance, respectively. 2. the Non-financial performance is confirmed in the international departments of all commercial banks. Moreover, the financial performance of international departments in the Melli, Saderat, Mellat and Sepah Banks is approved while the financial performance is not confirmed in the Tejarat Bank.
Volume 10, Issue 4 (Fall 2019)
Abstract
The stimulants are materials that increase alertness and reduce physical and mental fatigue. These drugs increase the activity of excitatory receptors and reduce the activity of inhibitory receptors in the central nervous system. Methamphetamine, also known as crystal, is a psychoactive substance. This drug is stimulating nerves and by a direct effect on the brain, mechanisms cause joy and excitement in people. Methamphetamine in low to moderate doses (5 to 30 mg) causes euphoria; excitement, increased heart rate, and blood pressure, mydriasis, increased body temperature and decrease appetite. High but non-lethal doses of methamphetamine cause mental disorders and psychotic symptoms, seizures, and rhabdomyolysis. Cardiovascular toxicity of methamphetamine-induced hypertension, arrhythmia, acute coronary syndrome and ischemic ventricular. The most important cellular mechanisms involved in the damage caused by Methamphetamine are oxidative stress, excitotoxicity, and mitochondrial damage. The synthesis of methamphetamine in illegal workshops mainly of six methods which are based on the raw materials are divided into two groups. Raw materials in the synthesis of methamphetamine are ephedrine and phenyl propanol. In reduction, methods involve Birch reduction, Nagai and hydrogenation Rosenmund ephedrine and pseudoephedrine are used as raw material, in Lockhart methods and amination reduction methods based on phenyl propanol as raw material.
Damoon aghazadeh Dokandari, Seyyed Mohammad Seyyed Mahmoudi, Alireza Setayesh Hagh,
Volume 14, Issue 7 (10-2014)
Volume 14, Issue 7 (10-2014)
Abstract
Throttling process through expansion valves causes a considerable amount of exergy loss so that reducing this loss improves the performance of compressed refrigeration cycle considerably. In the present work, the effect of using an ejector on the performance of a cascade refrigeration cycle is evaluated. It is concluded that the using ejector and selecting R134a as the high temperature circuit refrigerant cause the COP and second law efficiency to increase by approximately 6.5 percent as compared to the conventional cascade cycle with the same cooling capacity. In addition, several refrigerants including R717, R290, R134a, and R123 are examined to reveal the effect of refrigerant type in the high temperature circuit on the cycle performance. It is also found that, at a temperature of more than 255.4 K, for the evaporator of high temperature circuit, the refrigerant combination of R744-R123 results in a better performance as compared to the other combinations. Finally, the cycle performance is optimized with respect to the temperatures of low temperature evaporator, high temperature evaporator, and the ambient from the view points of both the first and second laws of thermodynamics. It is concluded that the COP and the second law efficiency are the highest when R123 is used as the refrigerant at the high temperature circuit.
Volume 15, Issue 2 (May & June 2024)
Abstract
In today's world, expanding the existing body of knowledge through research is one of the main pillars of progress in the educational system. To achieve this goal, it is necessary for teachers to have research literacy, which is a prerequisite for their engagement in research. Research literacy can improve the quality of educational processes by helping teachers to apply research-informed approaches in their classrooms. One of the first steps to empower teachers in this regard is to determine their current level of research literacy and identify the knowledge and skills that they need in order to engage in research effectively. The present study introduces the concept of research literacy as an essential construct with regard to teachers' research engagement and discusses its impact on improving teaching methods and ultimately the quality of education. Adopting a scoping review approach, this study elaborates on teachers’ roles in relation to the concept of research literacy. Furthermore, the proposed models for the construct of research literacy in the field of education are presented and evaluated. The findings of this study indicated that teachers need to have a critical understanding of research reports in order to find solutions to educational problems, make informed decisions, and implement the implications of research studies in their classrooms. Finally, aiming to strengthen the dynamism of the educational system and encourage teachers to put research findings into practice, a number of practical guidelines are proposed which can promote the status and culture of research in educational settings.
1. Introduction
The assumption underlying the present study is that language teachers need to develop a certain level of research literacy to be able to teach effectively. Teachers are expected not only to be good consumers of research but also to be engaged in limited classroom research to improve the gap between theory and practice. Teacher education programs normally expose teachers to a core of research methods and design; however, it is not clear whether the courses designed for this purpose can equip teachers with the necessary knowledge and skills to carry out both functions mentioned above. To deal with this issue, the concept of research literacy has been proposed in the last two decades with a number of conceptual models operationalized in the form of research literacy instruments. The argument is that the first step, in a long term plan for developing research literacy among teachers, is to measure their level of research literacy. The purpose of the present study was conduct a scoping review of the conceptual models of research literacy and their components and to suggest strategies for its dissemination among language teachers.
Research Question(s)
How is research literacy defined and what conceptual models are proposed for research literacy in the relevant literature?
2. Literature Review
The literature review is mainly focused on (a) studies which have tried to demonstrate the complexity of effective teaching and the type and diversity of decisions that teacher are supposed to make in their teaching practice; (b) studies which have focused on teachers’ engagement with research and its importance for their teaching efficacy; (c) the studies which have dealt with the need for research literacy among teachers. As there is a lack of review studies to show the scope of issues related to research literacy it is argued that the present scoping review is necessary to deal with this gap.
3. Methodology
The present scoping review followed the framework proposed by Arksey and O'Malley (2005) which includes the following five steps: formulating the review research question, searching the literature, selecting and screening the collected studies, classifying and presenting the data, and summarizing and presenting the results.
The inclusion criteria used in the present study were as follows:
1. Introduction
The assumption underlying the present study is that language teachers need to develop a certain level of research literacy to be able to teach effectively. Teachers are expected not only to be good consumers of research but also to be engaged in limited classroom research to improve the gap between theory and practice. Teacher education programs normally expose teachers to a core of research methods and design; however, it is not clear whether the courses designed for this purpose can equip teachers with the necessary knowledge and skills to carry out both functions mentioned above. To deal with this issue, the concept of research literacy has been proposed in the last two decades with a number of conceptual models operationalized in the form of research literacy instruments. The argument is that the first step, in a long term plan for developing research literacy among teachers, is to measure their level of research literacy. The purpose of the present study was conduct a scoping review of the conceptual models of research literacy and their components and to suggest strategies for its dissemination among language teachers.
Research Question(s)
How is research literacy defined and what conceptual models are proposed for research literacy in the relevant literature?
2. Literature Review
The literature review is mainly focused on (a) studies which have tried to demonstrate the complexity of effective teaching and the type and diversity of decisions that teacher are supposed to make in their teaching practice; (b) studies which have focused on teachers’ engagement with research and its importance for their teaching efficacy; (c) the studies which have dealt with the need for research literacy among teachers. As there is a lack of review studies to show the scope of issues related to research literacy it is argued that the present scoping review is necessary to deal with this gap.
3. Methodology
The present scoping review followed the framework proposed by Arksey and O'Malley (2005) which includes the following five steps: formulating the review research question, searching the literature, selecting and screening the collected studies, classifying and presenting the data, and summarizing and presenting the results.
The inclusion criteria used in the present study were as follows:
- Studies written in English
- Studies published in authoritative journals
- Studies published in the form of articles
- Studies dealing with the concept and models of research literacy
- Studies conducted in education and social sciences
- Studies published between 2000 to 2022
The exclusion criteria of the present study were as follows:
- Studies published in languages other than English
- The grey literature studies
- Studies published in disciplines other than education and social studies
Initially 334 studies were identified which were then reduced to 44 after the inclusion and exclusion criteria were applied through reading the title, abstracts and the relevant section of each paper.
4. Results
The results show that the proposed models of research literacy are based on teachers’ role in research. Their roles are classified as: (a) critical understanding of research reports; (b) the ability to engage in classroom research; (c) applying the research results to teaching practice.
With regard to the proposed models of research literacy, the results show that each proposed model include components which are more in line with the aims and underlying principles of teacher education in the country where the model was introduced. For example, in countries where critical understanding of research reports and their use in developing more effective teaching procedures is emphasised, teachers are expected to be able to identify the implication of the studies they have read and understood and to apply them to the relevant aspects of their teaching practice and to be able to collect research evidence helping them to deal with teaching and learning issues. On the other hand, in countries where teachers are trained to be involved actively in classroom research, they are expected to contribute the educational knowledge development and to be ready to be engaged in evidence-based practice. As it is evident the componenets of research literacy differs in each of these cases, although in both of them the knowledge and skills necessary to be consumer of research is shared.
4. Results
The results show that the proposed models of research literacy are based on teachers’ role in research. Their roles are classified as: (a) critical understanding of research reports; (b) the ability to engage in classroom research; (c) applying the research results to teaching practice.
With regard to the proposed models of research literacy, the results show that each proposed model include components which are more in line with the aims and underlying principles of teacher education in the country where the model was introduced. For example, in countries where critical understanding of research reports and their use in developing more effective teaching procedures is emphasised, teachers are expected to be able to identify the implication of the studies they have read and understood and to apply them to the relevant aspects of their teaching practice and to be able to collect research evidence helping them to deal with teaching and learning issues. On the other hand, in countries where teachers are trained to be involved actively in classroom research, they are expected to contribute the educational knowledge development and to be ready to be engaged in evidence-based practice. As it is evident the componenets of research literacy differs in each of these cases, although in both of them the knowledge and skills necessary to be consumer of research is shared.
Volume 15, Issue 4 (12-2015)
Abstract
The lateral spreading of mildly sloping ground and the liquefaction induced by earthquakes can cause major destruction to foundations and buildings, mainly as a result of excess pore water pressure generation and softening of the subsoil. During many large earthquakes, soil liquefaction results in ground failures in the form of sand boils, differential settlements, flow slides, lateral spreading and loss of bearing capacity beneath buildings. Such ground failures have inflicted much damage to the built environment and caused significant loss of life. The risk of liquefaction and associated ground deformation can be reduced by various ground improvement methods, including densification, solidification (e.g., cementation), vibro-compaction, drainage, explosive compaction, deep soil mixing, deep dynamic compaction, permeation grouting, jet grouting, piles group and gravel drains or SCs. Nowadays, using pile foundation is one of the popular solution for soils vulnerable to liquefaction. the pile with enough length more than liquefiable soil depth can reduce the large deformation and unacceptble settlements. Liquefaction and lateral deformation of the soil has caused extensive damage to pile foundations during past earthquakes. Several example of significant damages in pile foundation have been reported in the literature from the 1964 Niigata,1983Nihonkai-Chubu,1989 Manjil and 1995 kobe earthquakes. These damage have been observed mainly in coastal areas or sloping ground. evaluation of liquefaction in order to develop the northern and southern ports and implement coastal and offshore structures in Iran is of particular importance due to locating in a high seismic hazard zone and Liquefactable soil in coastal areas. Although, in recent years many studies have been conducted to understand the various aspects of this phenomenon, yet a lot of uncertainties have remained about the lateral deformations of the soil and its effects on deep foundations. In this study, behavior of pile groups (2 × 1, 1 × 3, 2 × 2 and 3 × 3) were evaluated using fully coupled three-dimensional dynamic analysis. Therefore, the influence of effective parameters such as number of piles, ground slope angle on soil and pile behavior has been studied using the finite element software Opensees SP v2.4. results indicate that most of the factors affecting the behavior of the pile, soil are not considered in the current design codes (such as JRA 2002) and these issues indicate the need to revise the current design and analysis methods.Lateral Pressures compared to that of JRA regulations show that these regulations cannot exactly predict pressures on pile and pile groups. Altogether comparing the results of numerical model of this research to various laboratory observations indicate that the use of numerical method can be reliable to predict the behavior of the soil and pile qualitatively and quantitatively using appropriate constitutive model and parameters for soil and pile. Keywords: Liquefaction soil, pile group, fully coupled numerical analysis, multi-surface-plasticity constitutive model.
Kamal Jahani, Parisa aghazadeh,
Volume 16, Issue 4 (6-2016)
Volume 16, Issue 4 (6-2016)
Abstract
Employing piezoelectric systems is one of the suitable methods for harvesting energy from mechanical vibrations available in the environment. In this work,single degree of freedom model for cantilever beam with piezoelectric layer is considered. Simulation contains nonlinear coefficients like: stiffness, damping and coupling coefficient. Governing system of equations is solved by multiple scales method. First with assuming one term in approximate response, the effects of all nonlinear parameters on frequency curve are investigated. Results show that assuming only one term in response evaluates the effect of nonlinear damping correctly. Increasing this coefficient leads to reduce the range of excitation frequency and maximum harvested power. But one term assumption couldn’t assess the effects of nonlinear stiffness and coupling coefficient logically. In this case, the peak of frequency response curve is independent of nonlinear coefficients. So for obtaining accurate results assuming at least two terms of response is necessary. Results show increasing nonlinear stiffness coefficient increase the maximum harvested power and the range of excitation frequency. The effect of nonlinear coupling coefficient is decreasing the maximum power because this coefficient increases the stiffness of the system.
Damoon aghazadeh Dokandari, Ali Naseri, Mokhtar Bidi, Ramin Haghighi Khoshkhoo,
Volume 18, Issue 1 (3-2018)
Volume 18, Issue 1 (3-2018)
Abstract
An ejector-expansion refrigeration cycle employing N2O is studied in this paper and thermodynamic and exergy analysis is carried out to find out the effect of some key factor within the system. The results show that Ejector-Expansion Refrigeration Cycle (EERC) obviously has the highest maximum coefficient of performance and exergy efficiency by about 12% and 14% more than Internal Heat Exchanger Cycle (IHEC); meanwhile these are about 15% and 16.5% higher than Vapor-Compression Refrigeration Cycle (VCRC) ones, respectively. Moreover, the total exergy destruction in N2O ejector-expansion cycle is 63.3% and 54% less than IHEC and VCRC and the exergy destructed in expansion process within EERC is 19.39% and 40.497% of total destruction less than IHEC and VCRC. Furthermore, the highest COP for vapor-compression refrigeration, internal heat exchanger and ejector-expansion refrigeration cycles is corresponding to the high side pressure of 7.328 Mpa, while this value for CO2 refrigeration cycle is about 8.5 Mpa.
Naghi aghazadeh, Shahram Khalilarya, Samad Jafarmadar, Ata Chitsaz Khoyi,
Volume 18, Issue 7 (11-2018)
Volume 18, Issue 7 (11-2018)
Abstract
In this article, a new power, cooling and heating cogeneration system consisting of a solid oxide fuel cell (SOFC) - gas turbine (GT), a heat recovery steam generator (HRSG), Generator-Absorber-heat eXchange (GAX) absorption refrigeration cycle and a heat exchanger for heat recovery (HR) has been studied from a thermodynamic and economic perspective. The modeling of this cycle was done by solving the electrochemical, thermodynamic and exergoeconomic equations for fuel cell and system components, simultaneously. The results showed that the exergy of our proposed combined cycle is 14.9% more and the irreversibility rate of this cycle is 10.6% less than that of the combined SOFC-GT-GAX systems in the same conditions. Also, the fuel cell and the afterburner have the highest rate of exergy destruction among other components due to irreversibility. Exergoeconomic analysis showed that the sum of uint cost of products (SUCP), the exergoeconomic factor, the capital cost rate and the exergy destruction cost rate for the overall system is equal to 331.1 $/GJ, 29.3%, 10.47 $/h and 25.32 $/h, respectively. Parametric studies showed that increasing the current density will increase the net electrical power, heating capacity of HRSG and HR heat exchanger, cooling capacity and total irreversibility. Also, with increasing of the current density, both the exergy efficiency and SUCP decrease.
Volume 25, Issue 1 (4-2021)
Abstract
Coopetition strategy is a relationship in which collaboration and competition co-exist, to create value in cooperation with their competitors and to appropriate a share of that value themselves in an all-win scenario. The focus of this study is to investigate the concept of competitive collaboration in the engineering services industry. In this regard, one of the innovations of the present study is to try to design a conceptual model for this strategy and then to modify it based on the Iranian engineering services. Using grounded theory, methodology as a qualitative method based on primary data of 12 in-depth interviews with experts in the field, a theoretical framework was formulated regarding the systematic view of Strauss and Corbin. The research data were analyzed in three stages: open coding (650 descriptive codes), axial coding and selective coding. The findings show that the final model consists of 6 main categories, 14 subcategories, and 98 abstract concepts. By gathering the data and evidence from analysis of inter-firm level, a conceptual model relationship for coopetition strategy in the field of engineering services. The research findings show that engineering services managers and policymakers need to pay attention to all categories of causal conditions, intervening conditions, contextual conditions, strategies and outcomes of competitive collaboration.
Volume 25, Issue 5 (9-2023)
Abstract
Bacterial endophytes associated with algae represent a rich source of bioactive metabolites and biostimulants that can be used practically in agriculture as biofertilizer. We carried out a series of experiments to study the diversity of bacterial endophytes associated with seaweed species of the Persian Gulf (PG) and Oman Sea (OS) and their capability in nourishing Mexican lime seedlings. We collected samples of brown, red, and green seaweed species (62 samples of brown, 79 of red and 49 of green) from intertidal zones of PG and OS in southern coastlines of Iran. The isolated bacteria were identified molecularly, morphologically and physiologically. Among 12 bacterial genera identified, the genus Bacillus had the highest frequency (51.51%). In addition to identification, results showed that all bacterial endophytes isolates were negative oxidase, most isolates (81.25 %) were positive catalase and could produce HCN, and all isolates produced IAA, from 0.897 μg mL-1 in Empedobacter falsenii to 0.085 μg mL-1 in Bacillus zhangzhouensis. Most isolates (96.77%) were able to grow on medium incorporated with different NaCl concentrations. Results of inoculation showed that lime seedlings colonized by B. aquimaris (MT278260), B. megaterium (MN626631) and B. zhangzhouensis (MN611359) had more growth and intended morphological characteristics than those lacking endophytes.
Volume 30, Issue 3 (Fall 2024)
Abstract
The study of international entrepreneurship in one of the most important and influential businesses in the economic world today, namely small and medium-sized businesses that are run by families, has been introduced as one of the vital fields of study by researchers. The study provides an international entrepreneurship model in small and medium family businesses in Iran. The study has been taken by adopting a qualitative approach of Grounded theory, through purposive sampling and data collection among 20 managers and employees of family businesses active in the food industry. Also, the data analyzed using interview tools during three common coding steps in the Strauss-Corbin approach. Data analyzed by Atlas ti software. The reliability of the research tool assessed using the two-coder agreement method. The designed model includes market strategies, networking, Iranian culture governing business, entrepreneurial capabilities, underlying factors (internal factors, external factors, area of business activity, political conditions of sanctions and government support), resources (financial, Technological and human resources), sustainable development, sustainable Currency and global practice are among the results of the research.
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