Viscometric Constants For Chitosan In Various Solvents

(Mohammad Reza Kasaai) 한국키틴키토산학회 2000 한국키틴키토산학회지 Vol.5 No.3

Association between Obesity and Bone Mineral Density by Gender and Menopausal Status

Mohammad Reza Salamat,Amir Hossein Salamat,Mohsen Janghorbani 대한내분비학회 2016 Endocrinology and metabolism Vol.31 No.4

Background: We investigated whether there were gender differences in the effect of obesity on bone mineral density (BMD) basedon menopausal status. Methods: We assessed 5,892 consecutive patients 20 to 91 years old who were referred for dual-energy X-ray absorptiometry(DXA) scans. All subjects underwent a standard BMD scan of the hip (total hip and femoral neck) and lumbar spine (L1 to L4) usinga DXA scan and body size assessment. Body mass index was used to categorize the subjects as normal weight, overweight, andobese. Results: BMD was higher in obese and overweight versus normal weight men, premenopausal women, and postmenopausal women. Compared to men ≥50 years and postmenopausal women with normal weight, the age-adjusted odds ratio of osteopenia was0.19 (95% confidence interval [CI], 0.07 to 0.56) and 0.38 (95% CI, 0.29 to 0.51) for obese men ≥50 years and postmenopausalwomen. Corresponding summaries for osteoporosis were 0.26 (95% CI, 0.11 to 0.64) and 0.15 (95% CI, 0.11 to 0.20), respectively. Compared to men <50 years and premenopausal women with normal weight, the age-adjusted odds ratio of low bone mass was 0.22(95% CI, 0.11 to 0.45) and 0.16 (95% CI, 0.10 to 0.26) for obese men <50 years and premenopausal women, respectively. Conclusion: Obesity is associated with BMD of the hip and lumbar spine and overweight and obese individuals have similar degreesof osteoporosis. This result was not significantly different based on gender and menopausal status, which could be an importantissue for further investigation.

Relationship between university brand personality and student behavioral loyalty

Mohammad Reza Karimi Alavijeh,Morteza Rezaee,Vahid Hosseinabadi 한국교육개발원 2014 KEDI Journal of Educational Policy Vol.11 No.2

The brand personality and status of the university among other universities are important for encouraging students to choose a particular university. This study examines different dimensions of the university brand personality and the effect of brand personality on the student-university relationship, student loyalty, and the moderating role of ethics on the research model. The sample of the first study includes all the students of public universities of Tehran city, and for the second study all the students of University of Tehran. 403 and 399 completed surveys were collected for the first and second studies. The results of an exploratory factor analysis show that the university brand personality has six dimensions with twenty-two scales. The results of structural equation modeling show that the university brand personality has a positive and meaningful effect on student-university relations, the relationship between student and university and the likelihood of students recommending the university to others, and the willingness to continue academic study. Ethics has a moderating role, but its effect and intensity are not meaningful.

Identification and Ranking of Factors Influencing International Market Segmentations for Direct Exports Study Case

Mohammad Reza Karimi Alavijeh,Farzaneh Naseri 대한산업공학회 2017 Industrial Engineeering & Management Systems Vol.16 No.4

The purpose of the present research was to identify and rank those factors which influence international markets segmentation in Iranian nuts and dried fruits industry. The present applied research was carried out in descriptive survey design, given the data collection methodology. The population consisted of members of Iranian Nuts and Dried Fruits Exporters Union (120 individuals representing 120 member companies). The sample size equaled the population through a head counting sampling procedure. To carry out this research, first 64 factors influencing international market segmentation were identified by systematic literature review and a questionnaire was prepared based on the research background to measure the factors influencing international market segmentation. The items of the questionnaire were rated using a 5-point Likert scale. Out of the 120 distributed questionnaires, 103 questionnaires were achieved and used in data analysis. The data were analyzed using descriptive statistics and decision tree in SPSS software program. The results revealed that among the 6 dimensions under study, market potential, legal environment, and infrastructure ranked first to third respectively while cultural outlook had the smallest effect on international market segmentation. Out of the 18 components considered, market cycle, customers’ demand, and specific competitors were of highest significance and stability and instability were found to be the least important. At the end, suggestions were made for exporters and future studies.

A Metamodeling Approach for Leader Progression Model-based Shielding Failure Rate Calculation of Transmission Lines Using Artificial Neural Networks

Mohammad Reza Bank Tavakoli,Behrooz Vahidi 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.6

The performance of transmission lines and its shielding design during a lightning phenomenon are quite essential in the maintenance of a reliable power supply to consumers. The leader progression model, as an advanced approach, has been recently developed to calculate the shielding failure rate (SFR) of transmission lines using geometrical data and physical behavior of upward and downward lightning leaders. However, such method is quite time consuming. In the present paper, an effective method that utilizes artificial neural networks (ANNs) to create a metamodel for calculating the SFR of a transmission line based on shielding angle and height is introduced. The results of investigations on a real case study reveal that, through proper selection of an ANN structure and good training, the ANN prediction is very close to the result of the detailed simulation, whereas the Processing time is by far lower than that of the detailed model.

Remote sensing analysis of unknown origin of a crater in western Yemen

Mohammad Reza Mansouri Daneshvar,Hamid Nejadsoleymani 대한공간정보학회 2017 Spatial Information Research Vol.25 No.4

The present study aims to detect unknown origin of a terrestrial structure in western Yemen based on the remote sensing procedure in order to enhance scientific database on the possible impact craters in the Middle Eastern countries. On this basis, a crater-shaped structure, named as Salab crater, was detected with a diameter of ~3.2-km. Topographical study indicated a circular morphology with two rings. Interior ring has a diameter of ~1-km and depth of ~100-m, while exterior ring has a diameter of ~2.2-km and depth of ~400-m. According to the geological data, the crater environ mainly has the different units outcropped of the Jurassic Amran limestone, the Cretaceous Tawilah sandstone, and the late Oligocene to early Miocene volcanic groups and intrusions. We indicated that the Salab crater is entirely located on Jurassic limestone of Amran group bedrocks with poor aquifer, low potential of water productivity and impure limestone deposits. Hence, the Salab crater could not be categorized as a volcanic crater or a karstic product. In addition, it could not be the remained from a salt-dome or a certain active hydrothermal pattern of springs. Nevertheless, to distinguish of the crater from old and fossil travertine crater or a possible impact crater, a detailed field work and a petrology investigation should be considered.

Gas Metal Arc Welding Process Control Based on Arc Length and Arc Voltage

Mohammad Mousavi Anzehaee,Mohammad Haeri,Ali Reza Doodman Tipi 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

In this paper, we present a method to dynamically observe two important variables of a Gas Metal Arc Welding (GMAW) process, i.e. arc voltage and arc length. To do this, we use Kalman filter to estimate these two variables in a high level noisy environment of GMAW process both in open and closed loop modes.

Multi-objective optimization of double wishbone suspension of a kinestatic vehicle model for handling and stability improvement

Mohammad Reza Bagheri,Masoud Mosayebi,Asghar Mahdian,Ahmad Keshavarzi 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.5

One of the important problems in the vehicle design is vehicle handling and stability. Effective parameters which should be considered in the vehicle handling and stability are roll angle, camber angle and scrub radius. In this paper, a planar vehicle model is considered that two right and left suspensions are double wishbone suspension system. For a better analysis of the suspension geometry, a kinestatic model of vehicle is considered which instantaneous kinematic and statics relations are analyzed simultaneously. In this model, suspension geometry is considered completely. In order to optimum design of double wishbones suspension system, a multi-objective genetic algorithm is applied. Three important parameters of suspension including roll angle, camber angle and scrub radius are taken into account as objective functions. Coordinates of suspension hard points are design variables of optimization which optimum values of them, corresponding to each optimum point, are obtained in the optimization process. Pareto solutions for three objective functions are derived. There are important optimum points in these Pareto solutions which each point represents an optimum status in the model. In other words, corresponding to any optimal point, a specific geometric position is determined for the suspension hard points. Each of the obtained points in the Pareto optimization can be selected for a special design purpose by designer to create an optimum condition in the vehicle handling and stability.

The caspase-3 inhibitor (peptide Z-DEVD-FMK) affects the survival and function of platelets in platelet concentrate during storage

Reza Shiri,Fatemeh Yari,Minoo Ahmadinejad,Shahram Vaeli,Mohammad Reza Tabatabaei 대한혈액학회 2014 Blood Research Vol.49 No.1

Background Although apoptosis occurs in nucleated cells, studies show that this event also occurs in some anucleated cells such as platelets. During storage of platelets, the viability of platelets decreased, storage lesions were observed, and cells underwent apoptosis. We investigated the effects of caspase-3 inhibitor on the survival and function of platelets after different periods of storage. Methods Platelet concentrates were obtained from the Iranian Blood Transfusion Organization in plastic blood bags. Caspase-3 inhibitor (Z-DEVD-FMK) was added to the bags. These bags along with control bags to which no inhibitor was added were stored in a shaking incubator at 22℃ for 7 days. The effects of Z-DEVD-FMK on the functionality of platelets were analyzed by assessing their ability to bind to von Willebrand factor (vWF) and to aggregate in the presence of arachidonic acid and ristocetin. Cell survival was surveyed by MTT assay. Background Although apoptosis occurs in nucleated cells, studies show that this event also occurs in some anucleated cells such as platelets. During storage of platelets, the viability of platelets decreased, storage lesions were observed, and cells underwent apoptosis. We investigated the effects of caspase-3 inhibitor on the survival and function of platelets after different periods of storage. Methods Platelet concentrates were obtained from the Iranian Blood Transfusion Organization in plastic blood bags. Caspase-3 inhibitor (Z-DEVD-FMK) was added to the bags. These bags along with control bags to which no inhibitor was added were stored in a shaking incubator at 22℃ for 7 days. The effects of Z-DEVD-FMK on the functionality of platelets were analyzed by assessing their ability to bind to von Willebrand factor (vWF) and to aggregate in the presence of arachidonic acid and ristocetin. Cell survival was surveyed by MTT assay. Results At day 4 of storage, ristocetin-induced platelet aggregation was significantly higher in the inhibitor-treated (test) than in control samples; the difference was not significant at day 7. There was no significant difference in arachidonic acid-induced platelet aggregation between test and control samples. However, at day 7 of storage, the binding of platelets to vWF was significantly higher in test than in control samples. The MTT assay revealed significantly higher viability in test than in control samples at both days of study. Conclusion Treatment of platelets with caspase-3 inhibitor could increase their functionality and survival.

Aeroelastic analysis of cantilever non-symmetric FG sandwich plates under yawed supersonic flow

Mohammad Hosseini,Ali Ghorbanpour Arani,Mohammad Reza Karamizadeh,Hassan Afshari,Shahriar Niknejad 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.29 No.6

In this paper, a numerical solution is presented for supersonic flutter analysis of cantilever non-symmetric functionally graded (FG) sandwich plates. The plate is considered to be composed of two different functionally graded face sheets and an isotropic homogeneous core made of ceramic. Based on the first order shear deformation theory (FSDT) and linear piston theory, the set of governing equations and boundary conditions are derived. Dimensionless form of the governing equations and boundary conditions are derived and solved numerically using generalized differential quadrature method (GDQM) and critical velocity and flutter frequencies are calculated. For various values of the yaw angle, effect of different parameters like aspect ratio, thickness of the plate, power law indices and thickness of the core on the flutter boundaries are investigated. Numerical examples show that wings and tail fins with larger length and shorter width are more stable in supersonic flights. It is concluded for FG sandwich plates made of Al-Al2O3 that increase in volume fraction of ceramic (Al2O3) increases aeroelastic stability of the plate. Presented study confirms that improvement of aeroelastic behavior and weight of wings and tail fins of aircrafts are not consistent items. It is shown that value of the critical yaw angle depends on aspect ratio of the plate and other parameters including thickness and variation of properties have no considerable effect on it. Results of this paper can be used in design and analysis of wing and tail fin of supersonic airplanes.