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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Structural Engineering and Geotechnics
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: As regards if curing stops for some time and then resumes again, then strength gain will also stop and reactive, in this study with choose suitable curing conditions after improper first curing (recurring) for normal and silica-fume concrete, Effect of this curing conditions on strength and permeability was investigated. The results from tests such as compressive strength, capillary water absorption and water penetration under pressure, indicates that curing after 28 days for concretes with improper first curing, especially for silica-fume concretes could be effective and reduction permeability and increase compressive strength of concretes was observed
- انتشار مقاله: 29-12-1393
- نویسندگان: Ali Delnavaz,Mohammad Reza Pezeshkian
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Teaching Language Skills
- نوع مقاله: Journal Article
- کلمات کلیدی: Assessment,Performance Assessment,Accountability
- چکیده:
- چکیده انگلیسی: Accountability concerns in language education call for the development of more valid and authentic measures of assessment. In light of these concerns, performance assessment has received increasing interest in the context of teacher education programs and teacher licensing over the last decade. In Iran, a recent policy adopted by Farhangian University aims at assessing the professional competencies of its ELT graduates by requiring them to go through a performance assessment as part of the licensing requirements. Mounting concerns regarding the validity of traditional tests used for teacher certification (Mitchell, Robinson, Plake, & Knowles, 2001) have motivated Farhangian University to develop its own performance assessment. Therefore, the present study explored the components of the performance assessment through detailed analysis of the Curriculum Document of the English Major, review of literature, and investigation of the stakeholders' perspectives. To this end, in this exploratory study, convenience, purposive, and cluster sampling procedures were used for the selection of the teacher educators, student-teachers, and mentor teachers. Then, in-depth interviews were conducted with the stakeholders. Finally, based on the content analysis of the above-mentioned sources which resulted in a strong agreement, a performance assessment scheme with seventeen items was developed. However, results of the factor analysis yielded a thirteen-factor performance assessment scheme to be used as the criterion for assessing the professional competencies of student-teachers.
- انتشار مقاله: 03-08-1395
- نویسندگان: Gholamreza Kiany,Mohammad Nabi Karimi,Monireh Norouzi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of the Iranian Chemical Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Solvent-free,Protection,Carbonyl compound,Silica sulfuric acid,2,4-Dinitrophenylhydrazone
- چکیده:
- چکیده انگلیسی: Silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardous
protection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.- انتشار مقاله: 15-02-1388
- نویسندگان: Mehdi Fallah-Mehrjardi,Ali Reza Kiasat
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Optoelectronical Nanostructures
- نوع مقاله: Journal Article
- کلمات کلیدی: Graphene,Hydrodynamic Equations,Electrostatic Waves,Dispersion Relation
- چکیده:
- چکیده انگلیسی: In this paper, by using a quantum hydrodynamic plasma model which incorporates the important quantum statistical pressure and electron diffraction force, we present the corrected plasmon dispersion relation for graphene which includes a k quantum term arising from the collective electron density wave interference effects (which is integer and constant and k is wave vector). The longitudinal plasmons are the electrostatic collective excitations of the solid electron gas. We have tried to use the quantum hydrodynamic model for studying of propagation of the electrostatic surface wave in single layer graphene, in the presence of an external and uniform magnetic field. The direction of magnetic field was selected in plane of graphene sheet. It shows the importance of quantum term from the collective electron density wave interference effects. By plotting the dispersion relation derived, it has been found that dispersion relation of surface modes depends significantly on these quantum effects (Bohm’s potential and statistical terms) and it should be taken into account in the case of magnetized or unmagnetized plasma; we have noticed successful description of the quantum hydrodynamic model. The quantum corrected hydrodynamic model can effectively describe the Plasmon dispersion spectrum in degenerate plasmas, since it takes into account the full picture of collective electron-wave interference via the quantum Bohm’s potential. By plotting the normalized dispersion relation, the behavior of two different wave types (lower- and higher- branches) was predicted. It was found that the lower-branch should not be propagated to the specific wave number (cut-off frequency). By drawing of the contour curve of the lower- and higher-branches modes, the areas that modes can be propagated were obtained. So, Quantum hydrodynamic model is an effective way to study the waves in various media.
- انتشار مقاله: 23-06-1395
- نویسندگان: Alireza Abdykian,Zahra Safi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Optimization in Industrial Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Production Planning,Simulated Annealing,dynamic cellular manufacturing systems,group layout
- چکیده:
- چکیده انگلیسی: In this paper, a mixed-integer linearized programming (MINLP) model is presented to design a group layout (GL) of a cellular manufacturing system (CMS) in a dynamic environment with considering production planning (PP) decisions. This model incorporates with an extensive coverage of important manufacturing features used in the design of CMSs. There are also some features that make the presented model different from the previous studies. These include: 1) the variable number of cells, 2) machine depot keeping idle machines, and 3) integration of cell formation (CF), GL and PP decisions in a dynamic environment. The objective is to minimize the total costs (i.e., costs of intra-cell and inter-cell material handling, machine relocation, machine purchase, machine overhead, machine processing, forming cells, outsourcing and inventory holding). Two numerical examples are solved by the GAMS software to illustrate the results obtained by the incorporated features. Since the problem is NP-hard, an efficient simulated annealing (SA) algorithm is developed to solve the presented model. It is then tested using several test problems with different sizes and settings to verify the computational efficiency of the developed algorithm in compare to the GAMS software. The obtained results show that the quality of the solutions obtained by SA is entirely satisfactory in compare to GAMS software based on the objective value and computational time, especially for large-sized problems.
- انتشار مقاله: 14-12-1391
- نویسندگان: Reza KiA,Nikbakhsh Javadian,Reza Tavakkoli-Moghaddam
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Language and Translation
- نوع مقاله: Journal Article
- کلمات کلیدی: Textual input enhancement,Causative Construction,Interactionally modified input,VAK learning style
- چکیده:
- چکیده انگلیسی: This study sought to investigate the effect of the two input types interactionally modified input (IM) and textual input enhancement (TIE), the impact of a commonly used learning styles taxonomy as the Visual, Auditory and Kinesthetic learning styles (VAK) by itself as well as the interactional effect of perceptual learning styles and input types on the causative construction development of EFL learners. To this end, 120 female Iranian EFL learners from three language schools in Tehran participated in this research and were divided into two experimental groups of 60. The study adopted a pretest-posttest design and learner’s grammar knowledge was measured before and after providing them with instructional treatment through IM input and TIE techniques. The data were analyzed through a two-way ANOVA. The results of the study indicated that IM input was significantly more effective than TIE in promoting the participants' knowledge of the target structure. The comparison of the posttest means scores also revealed that the VAK style was not an influential factor in second language learners’ target form knowledge, while a significant interaction between input type and learning styles turned out to have a beneficial effect if they synchronize in classrooms.
- انتشار مقاله: 26-08-1397
- نویسندگان: Motahar Tavakoly,Gholamreza Kiany,Mohammad R. Hashemi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Industrial Engineering International
- نوع مقاله: Journal Article
- کلمات کلیدی: Cell formation,dynamic cellular manufacturing systems,multi-objective model,group layout
- چکیده:
- چکیده انگلیسی: This paper presents a multi-objective mixed-integer nonlinear programming model to design a group layout of a cellular manufacturing system in a dynamic environment, in which the number of cells to be formed is variable. Cell formation (CF) and group layout (GL) are concurrently made in a dynamic environment by the integrated model, which incorporates with an extensive coverage of important manufacturing features used in the design of CMSs. Additionally, there are some features that make the presented model different from the previous studies. These features include the following: (1) the variable number of cells, (2) the integrated CF and GL decisions in a dynamic environment by a multi-objective mathematical model, and (3) two conflicting objectives that minimize the total costs (i.e., costs of intra and inter-cell material handling, machine relocation, purchasing new machines, machine overhead, machine processing, and forming cells) and minimize the imbalance of workload among cells. Furthermore, the presented model considers some limitations, such as machine capability, machine capacity, part demands satisfaction, cell size, material flow conservation, and location assignment. Four numerical examples are solved by the GAMS software to illustrate the promising results obtained by the incorporated features.
- انتشار مقاله: 11-07-1399
- نویسندگان: Reza Kia,Hossein Shirazi,Nikbakhsh Javadian,Reza Tavakkoli-Moghaddam
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Advances in Computer Engineering and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: delay,Throughput,Packet Loss,Vanet,Quality of Service (QoS)
- چکیده:
- چکیده انگلیسی: The systems in which information and communication technologies and systems engineering concepts are utilized to develop and improve transportation systems of all kinds are called “The Intelligent Transportation Systems (ITS)”. ITS integrates information, communications, computers and other technologies and uses them in the field of transportation to build an integrated system of people, roads and vehicles by utilizing advanced data communication technologies. Vehicular Ad-hoc Networks which is a subset of Mobile Ad-hoc Networks, provide Vehicle to Vehicle (V2V), Vehicle to Roadside (V2R) and Vehicle to Infrastructure (V2I) communications and plays an important role in Intelligent Transportation System. Due to special characteristics of VANETs, QoS (Quality of Service) provisioning in these networks is a challenging task. QoS is the capability of a network for providing superior service to a selected network traffic over various heterogeneous technologies. In this paper we present an overview of Vehicular Networks, QoS Concepts, QoS challenges in VANETs and approaches which aim to enhance the Quality of Service in Vehicular Networks
- انتشار مقاله: 16-01-1396
- نویسندگان: Mohammadreza Pourkiani,Sepideh Adabi,Sam Jabbehdari,Ahmad Khademzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Advances in Computer Engineering and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: ITS,Vanet,AD-hoc Networks,Mobile Communications
- چکیده:
- چکیده انگلیسی: The Intelligent Transportation System (ITS) provides wireless and mobile communication between vehicles and infrastructure to improve the safety of transportation and make the journey more enjoyable. This system consists of many fixed and mobile nodes (Vehicles, Trains, Vessels, Air planes), Wireless and Wired Telecommunication Technologies to exchange information between mobile nodes or between mobile nodes and fixed stations. The most common transportation tools are cars. Vehicular Ad-hoc Networks as an Application of Mobile Ad-hoc Networks and one of the subsets of Intelligent Transportation System provides wireless Ad-hoc communication between vehicles. VANET is a mobile wireless technology which is designed to improve safety of transportation with exchanging real time data between vehicles and providing different services to the users. It has special characteristics like high mobility and provides a broad range of services to the users, so it has been emerged as one of the research interests in the field of computer and telecommunication networks. In This paper we present different aspects of ITS and VANET to help the researchers to understand the Architecture, Communication Technologies and Applications of these networks.
- انتشار مقاله: 03-02-1395
- نویسندگان: Mohammadreza Pourkiani,Sam Jabbehdari,Ahmad Khademzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pathology
- نوع مقاله: Journal Article
- کلمات کلیدی: Urinary bladder,like carcinoma,Carcinoma in situ
- چکیده:
- چکیده انگلیسی: Lymphoepithelial - like carcinoma, is rarely recognized in the urinary bladder and less commonly occurs with papillary transitional cell carcinoma i.e. mixed pattern. Also, less uncommon is the occurrence of carcinoma in situ changes in the adjacent urothelium of these tumors. Here, a case of lymphoepithelial – like carcinoma and papillary transitional cell carcinoma associated with carcinoma in situ changes of urothelium of the urinary bladder has been reported the prognosis of this type of malignancy as well as its management will be discussed. Meanwhile, immunohistochemical stains have been carried out to differentiate it from lymphoma of the urinary bladder and the findings will be discussed.
- انتشار مقاله: 03-06-1396
- نویسندگان: Yahya Attaran,Simin Moghdam,Ahmad Monabati,Reza Sarkeshikian
- مشاهده