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Search Results: 1 - 10 of 4597 matches for " Majid Abbas Pour "
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Measuring the Noise Caused by Tehran Metro
Majid Abbas Pour,Faezeh Mir Heidari
Audiology , 1999,
Abstract: One of the most common and important sources of noise in the residential environments are vehicles such as airplanes and subways. Trafficking of vehicles in streets and highways, psychologically, have damaging impacts on people living close to such areas. The development and expansion of the trading and industrial units is another factor that causes more and more exposure to noise.We have aimed at measuring the noises caused by vibration of subways of the Line of Karaj-Tehran-Mehrshahr and its effect on its surrounding area.To study this effect we designed a mathematical model and put the information of this subway line in the mentioned model. Then we analyzed the findings.This model demonstrated that we can control the harsh noise of the subway by reducing the speed of the train to 60Km/h in some points and increase in other parts to 130Km/h.
A Noise Measurement Study of the Traffic in the Modarres High Way in Tehran
Amir Hossein Izad Doustdar,Parvin Nasiri,Majid Abbas Pour
Audiology , 1999,
Abstract: We measured the noise caused by Vehicles and its subjective effects in the Modarres high way In Tehran. we examined 143 cases in 11 stations in the mentioned pathway with an accuracy of 95% and a standard deviation of 39%. The noise criteria of Leq and the number of vehicles were determined in dBA. The loudness contours were also measured in some stations to determine the subjective impacts of noise. Then the correlation of the responses of the interviewees with sound pressure level was measured. Based on our findings, decrease of the noise of traffic sources should be considered three levels: the first level is noise reduction at the level of source, e.g. the vehicles;the second is Noise reduction at the traffic level and the third is noise reduction at the level of general activity.
Effects of extremely low-frequency electromagnetic fields on learning and memory and anxiety-like behaviors in rats
Zahra Akhtary,Ali Rashidy-Pour,Abbas Ali Vafaei,Majid Jadidi
Koomesh , 2011,
Abstract: Introduction: Although past research has suggested that acute exposure to the extremely low-frequency electromagnetic fields (ELFEFs) can impair cognitive functions, data on chronic exposure remained scare. Only a few studies investigated the effects of chronic ELFEFs on cognitive functions, but the results are controversial. Thus, the aim of the present study was to study whether chronic exposure to ELFEFs can affect cognitive functions and anxiety-like behaviors in rats. Materials and Methods: Thirty-five male Wistar were divided into control and exposed (10 or 100 uT). Exposed rats were continuously exposed to a 50 Hz magnetic field of 10 or 100 μT for four weeks. Then, cognitive functions of all rats were tested in the Morris water maze and passive avoidance tasks. Also, anxiety-related behaviors of all rats were examined in the elevated- plus maze and light-dark box. Results: No significant differences were found between control and exposed in learning acquisition, memory retention and anxiety-related behaviors. Conclusion: Our results showed that chronic exposure to ELFEFs neither change cognitive functions nor anxiety-related behaviors in rats.
Factor Controlling Reservoir Properties and Flow Unit Determination in the Ilam Formation of Dezfol Embayment at Zagros Fold-Thrust Belt, Southwest of Iran  [PDF]
Peiman Rezaie, Akram Jooybari, Majid Mehdi Pour, Mansour Gorbani
Open Journal of Geology (OJG) , 2016, DOI: 10.4236/ojg.2016.67051
Abstract: Dezfol embayment in the Southwest of Iran is located in the Zagros fold-thrust belt, which is one of the world’s largest petroleum provinces. Ilam Formation (Santonian-Companian) is one of the reservoir formations in this area that has been less studied. This paper focused on reservoir properties in this formation using petrography and petrophysics data. According to the petrography studies Ilam Formation composed of limestone as dominant lithology. Detailed petrographic analyses, have led to identification of 10 micro-facies which are represented as a carbonate ramp depositional model. Also petrographic analyses are revealed that cementation, dissolution, compaction and dolomitization are most important digenetic processes. Detailed petrographic analyses and petrophysics data showed that due to mud-supported nature of more facies
Relationship between Personality Types and Job Stress among Teachers at First Period (Guidance Schools) and Second Period of High School (Secondary Schools)  [PDF]
Abbas Sadeghi, Gholam Hossein Niyafar, Ali Hossein Pour, Anita Zamani, Fatemeh Gholami
Creative Education (CE) , 2016, DOI: 10.4236/ce.2016.73056
Abstract: This research has investigated the relationship between John Halland’s personality types (realist, investigative, conventional) with job stress among teachers at first period (guidance school) and second duration of high school (secondary school). 327 teachers were selected by multistage cluster sampling method and Philip Rice job stress questionnaire and John Halland’s job-personality questionnaire were used. Pearson correlation coefficient, linear regression and the analysis of multivariable variance (Manova) were used to measure the relationships. The results showed that there was a reversed relationship between personality types and the degree of stress, with correlation coefficient of r = -1.15, respectively, in the level of p = 0.05 and reversed relationship between conventional personality type and job stress was obtained by (r = -1.17). There was not any significant relationship between realist and investigative personality type with job stress of teachers and there was just a significant relationship between gender, personality type and the degree of stress in the level of (p = 0/05). Also, the degrees of stress in male teachers were more than female.
A Novel Technique for Rotor Bar Failure Detection in Single-Cage Induction Motor Using FEM and MATLAB/SIMULINK
Seyed Abbas Taher,Majid Malekpour
Mathematical Problems in Engineering , 2011, DOI: 10.1155/2011/620689
Abstract: In this article, a new fault detection technique is proposed for squirrel cage induction motor (SCIM) based on detection of rotor bar failure. This type of fault detection is commonly carried out, while motor continues to work at a steady-state regime. Recently, several methods have been presented for rotor bar failure detection based on evaluation of the start-up transient current. The proposed method here is capable of fault detection immediately after bar breakage, where a three-phase SCIM is modelled in finite element method (FEM) using Maxwell2D software. Broken rotor bars are then modelled by the corresponding outer rotor impedance obtained by GA, thereby presenting an analogue model extracted from FEM to be simulated in a flexible environment such as MATLAB/SIMULINK. To improve the failure recognition, the stator current signal was analysed using discrete wavelet transform (DWT). 1. Introduction Induction motors (IMs) play an important role in many industrial processes. Hence, IM failures should be detected at early stages before they become catastrophic and lead to shutdowns and enhanced maintenance costs. Condition monitoring is desirable for increasing machinery availability, reducing consequential damage, and improving operational efficiency [1–3]. IM faults may occur in three main parts of the machine; stator, rotor, and bearings. Rotor bars are commonly broken in squirrel cage induction motor (SCIM) due to several causes [4, 5], including (1) thermal stress, (2) magnetic stress, (3) residual stresses from manufacturing, (4) dynamic stress from shaft torques, (5) mechanical stress owed to bearing failure, and (6) environmental stresses such as moisture. In terms of condition monitoring, fault detection in SCIM is studied in two categories; steady-state condition and during start-up transient condition. For many years, researchers have focused on fault detection methods which are based on steady state such as FFT. Recently, following progress in signal processing, methods based on study of the start-up transient current have attracted attention. Traditional methods for monitoring the rotor conditions are based on frequency domain analysis of stator currents [6, 7], mechanical vibrations [8], fluxes on search coils [9], and rotor speed [10] in steady state. Motor current signature analysis (MCSA) is used by many researchers due to its availability and simplicity. The broken bars induce some harmonic components with special frequencies in stator currents (sideband frequencies), as below where is the slip and is the supply frequency. Bar
EFL Students’ Attitudes towards Learning English Language: The Case of Libyan Secondary School Students
Mohamad Jafre Zainol Abidin,Majid Pour-Mohammadi,Hanan Alzwari
Asian Social Science , 2012, DOI: 10.5539/ass.v8n2p119
Abstract: This study investigated Libyan secondary school students’ attitudes towards learning English in terms of the behavioral, cognitive and emotional aspects. It also explored whether there is any significant difference in the students’ attitudes towards English language based on their demographic profiles i.e., gender, field and year of study. A total of 180 participants in the three study years from three specializations of Basic Sciences, Life Sciences, and Social Sciences took a questionnaire as a measuring instrument. Regarding the three aspects of attitude i.e., cognitive, behavioral, and emotional, the participants showed negative attitudes towards learning English. On the demographic profile, there were statistically significant attitudinal differences regarding gender and field of study but not year of study. Based on the research findings, some recommendations are finally presented.
Attitudes towards Teaching and Learning Test-taking Strategies for Reading Comprehension Tests: The Case of Iranian EFL Undergraduates
Majid Pour-Mohammadi,Mohamad Jafre Zainol Abidin
Journal of Studies in Education , 2011, DOI: 10.5296/jse.v1i1.1028
Abstract: Reading, as the most important academic language skill, receives the special focus in second or foreign language teaching. In addition, tests are regularly applied to evaluate academic performance. There are several cognitive and psychological factors which affect test performance. One of such important test-related factors is test-taking strategies, also known as testwiseness. This study was set to probe the attitudes of Iranian EFL undergraduates towards training test-taking strategies. A set of 22 test-taking strategies for multiple-choice reading comprehension tests was taught as extra material to 30 EFL undergraduates in their regular reading classes within 11 sessions. A Likert rating-scale questionnaire was administered at the end of semester. Overall, students revealed positive opinions on teaching and learning of test-taking strategies. Results are discussed and some recommendations are ultimately provided.
Effects of stress related acute exercise on consolidation of implicit motor memory
Farhad Ghadiri,Ali Rashidy-Pour,Abbas Bahram,Saleh Zahediasl
Koomesh , 2012,
Abstract: Introduction: Extensive evidence documents arousal modulation of declarative memory in humans. However, little is known about the arousal modulation of implicit motor memory. The purpose of this study was to examine the effects of a post-acquisition acute exercise stress on implicit motor memory consolidation.Materials and Methods: Forty healthy subjects were randomly divided into stress (10 men and 10 woman) and non- stress (10 men and 10 woman) groups. Experiment consisted of two phases of acquisition and retention. Serial Color matching (SCM) task was used for this study. In acquisition period, all groups practiced the task for six blocks of 150 trials. Following, the stress group performed exercise on a treadmill until the moment of exhaustion while the non stress group did rest. In retention, all groups practiced the SCM task in one block. During the experiment the trends of saliva cortisol changes were measured.Results: Acute exercise stress leads to a significant increase in salivary cortisol level. While the non-stress group did not show enhancement of SCRT learning across the 24 hours delay interval, the stress group showed substantial enhancement across the same time (P<0.05).Conclusion: Our findings indicate that acute stress after acquisition can facilitate the implicit motor memory consolidation.
Central mineralocorticoid receptors mediate impairing effects of corticosterone on memory retrieval in rats
Mehdi Khaksari,Ali Rashidy-Pour,Abbas Ali Vafaei
Physiology and Pharmacology , 2008,
Abstract: Introduction: Previous studies have indicated that stress levels of glucocorticoid hormones induce impairment of long term memory retrieval, but the underlying mechanisms (genomic or non-genomic) are not clear. To clarify this issue, we investigated the involvement of brain corticosteroid receptors and protein synthesis in the glucocorticoid-induced impairment of memory retrieval. Methods: 140 young rats were trained in the water maze (WM) task with six trials per day for six consecutive days. Retention of the spatial training was assessed 24 h after the last training session with a 60-s probe trial. Experiments included intraventricular injections of anisomycin ( 187.5 or 450 μg/5μl) , a specific protein synthesis inhibitor or specific antagonists for mineralocorticoid receptors (MR, 37.5, 75, 150 μg/5ul) or glucocorticoids receptors (GR, 75 or 150 μg/5ul) before corticosterone administration (1 mg/kg) shortly before retention testing. Results: The results showed that administration of anisomycin did not change the corticosterone response. Administration of the MR, but not GR, antagonist blocked the corticosterone-induced response. Conclusion: These findings provide evidence for the view that glucocorticoids impair memory retrieval through non-genomic mechanisms involving an interaction with central MRs.
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