Showing 11 results for Namazi
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Although faculty members’ job satisfaction has received remarkable attention over the last two decades, there has been a long-lasting lack of a questionnaire to measure it in the Iranian context. Thus, the present study purported to develop and validate a questionnaire with adequate psychometric properties to measure Iranian English faculty members’ job satisfaction. To this aim, two samples of faculty members for the first pilot study (n = 62) and the second pilot study (n = 254) were selected from Ayatollah Borujerdi University and Lorestan University through a random sampling method. Based on the past literature, a pool of items (n = 74) was extracted and subjected to an eleven-step systematic procedure: content analysis and sampling; creating an item bank; running the first pilot; creating item pool one; expert judgment to evaluate the sub-scales; running an interview and think-aloud protocol; running Cronbach’s alpha; running the second pilot; running exploratory factor analysis, confirmatory factor analysis, and Cronbach’s alpha; creating item pool two; and expert review. Results yielded a 60-item questionnaire with 6 sub-scales: 1. payment and rewards (10 items); promotion (7 items); supervision and interaction (17 items); job security (7 items); facilities of universities (7 items); and work nature (10 items). The hope is that the present questionnaire can be used for research and educational purposes in the future.
Volume 8, Issue 2 (Spring 2023)
Abstract
Aims: Musculoskeletal disorders (MSDs) are among the most prevalent health problems and one of the causes of occupational disability in administrative professions. This study aimed to describe the rate of skeletal disorders among Office Workers (OWs) in Khoi Health Center.
Method and Materials: In this descriptive study using convenience sampling, 100 OWs patients were selected from the Khoi Health Center under the supervision of the Khoi Faculty member of Medical Sciences. Data were collected through a demographic questionnaire in which questions were related to various MSDs, The Quebec Back Pain Disability Scale and Roland – Morris Disability Questionnaire were raised. Data were entered into SPSS 19 software and analyzed using descriptive analysis.
Findings: In total, 100 OWs participated in the study and answered the questions (100% response rate). Back pain and neck pain were the most common complaint areas of the participants, respectively (83%). Twenty participants (20%) of OWs stated that they did not pursue any pain treatment or pain management. Also, the majority of participants (N=100, 100%) believed that they have pain in different parts of the body. However, 85 participants (85%) stated that they frequently change their position to keep their back comfortable. However, the mean expression of pain by the participants was moderate, and 85 participants (85%) stated that they had difficulty sitting in a chair for several hours.
Conclusions: This study showed that most of the studied OWs suffered from some kind of chronic skeletal disorders without any treatment/pain management. Therefore, it is highly recommended to conduct further studies to confirm these results in this special target group who work in the Khoi health center and investigate the causes of pain.
Volume 8, Issue 4 (Fall 2023)
Abstract
Aims: Work-related Musculoskeletal Disorders (WMSDs), particularly Chronic Low Back Pain (CLBP), are a growing public health concern among office workers due to sedentary work styles. This study will aim to investigate the prevalence and risk factors of WMSDs among office workers in Khoi, Iran.
Method and Materials: A descriptive study will be conducted with a convenience sample of 100 office workers at Health Centers in Khoi, Iran. Data will be collected through a selfadministered questionnaire on demographics characteristics, work-related factors of musculoskeletal disorders and musculoskeletal symptoms and finally will be analyzed through SPSS.
Conclusion: This study will provide a positional approach in order to be able to determine the situation of WMSDs and related factors among office workers in Khoi, Iran. Additionally, based of these data, the researchers could design proper interventional preventive program to improving their WMSDs and reducing related among office workers.
Sayed Mostafa Hosseinalipour, Mohammadmehdi Namazi, Arvin Behravan, Khashayar Ghadiri, Masoud Madadelahi,
Volume 14, Issue 9 (12-2014)
Abstract
In the present study, fabrication and performance testing of a flameless catalytic pad has been investigated. The catalyst was prepared with 1g of H2PtCl6.6H2O solved in 0.5 liter solvent contains 50% water and 50% ethanol and sprayed on the alumina - silica fiber mat as the catalyst support. The wet pad was dried and calcined before usage. The performance of the heater was evaluated by design and fabrication of a test stand which was capable of measuring parameters such as temperature at surface and in depth of the catalyst layer, the amount of pollutants such as CO and NOx, flow rate and pressure of the fuel and surface air circulation in front of the pad. In addition, by placing the panel containing the pad in an environmental test chamber, the effect of different climate conditions in five cities of Iran, i.e., Borojerd, Khalkhal, Lavan, Mahshahr and Puladshahr were investigated. Average surface temperature of the pad was measured about 350°C. No NOx was detected and CO emission of the burner was measured up to 5ppm. In Khalkhal conditions with the lowest temperature and humidity, the highest temperature at surface was recorded and the maximum CO emissions in Mahshahr with the highest temperature and humidity was about 3ppm. It was shown that increasing the fuel flow rate increases the surface temperature and CO emissions. It was also shown that an increase of environment temperature and humidity, increases the surface temperature.
Farhang Honarvar, Seyed Abbas Arham Namazi,
Volume 14, Issue 15 (Third Special Issue 2015)
Abstract
Measurement of wave velocity in materials is very important.It has applications in ultrasonic thickness gauging as well as estimating the elastic constants of materials. In this paper, it is intended to improve the accuracy of wave velocity measurements by signal processing techniques. For this purpose, the SAGE algorithm, which is a model-based estimation technique, is implemented. Using SAGE, the overlapping echoes are separated and consequently the time-delay between these echoes is estimated more accurately. The signal processing scheme reduces the adverse effects of noise too. To demonstrate the effectiveness of the proposed technique, an AISI 4140 steel block with four steps of thicknesses 10, 15, 20, and 25 mm was tested by the immersion ultrasonic testing technique. The time-delaybetween echoes obtained from each step was measured fifty times and by averaging these measurements, the actual time-delay and its uncertainty were estimated. The thickness of the block at each step was also measured by a micrometer. Using the time-delay and thickness data, the wave velocity and its uncertainty were estimated for each of the four thicknesses. The results shows that this technique can reduce the uncertainty of wave velocity measurements significantly.
Mir Boyok Ehghaghi, Mohammad Vajdi, Mohammad Namazizadeh, Maryam Hajipour,
Volume 17, Issue 3 (5-2017)
Abstract
Centrifugal pumps as a heart of the system which are used to move fluids are used widely in most of the industries and have considerable contribution in the amount of energy consumption, so improving of their performance has been attended for researchers .In this paper the aim of studying is the effect of double splitter blades on pump’s performance numerically and experimentally. Three type impellers have been made as experimental investigation. Pump with this impellers is tested and extracted the performance curve. Also, for investigation of the flow pump has been simulated numerically by ANSYS-CFX commercial code. Numerical method of finite volume with k-ω SST turbulence model for numerical analysis. Numerical and experimental results show reasonable agreement that increasing of head and variation of NPSHR due to adding of double splitter blades. The maximum head increased was obtained related to third type of Impeller about 6.33 percent. Furthermore, third type is selected as best impeller. Also, it is observed that around point of designing of pump the effect of double splitter blades on pump’s performance is more significant and deviation from this point will decrease the effect of it.
Zafar Namazian, Jafar Namazian,
Volume 17, Issue 6 (8-2017)
Abstract
In the present study, modeling of two-phase flow through porous medium is performed by Lattice Boltzmann method; moreover, the porous medium with different porosity ratio are examined. The Shan–Chen-type (SC) multiphase lattice Boltzmann model at D2Q9 network is used to simulate the two phase flow. To validate the used Fortran code in the simulations, first, two-phase flow in channel with hydrophobic and hydrophilic surface, and then a droplet on the surface with different hydrophilic and hydrophobic are simulated. Achieving optimized array of porous medium which reduces the leakage flow rate and fluid penetration was the primary aim of our study. To achieve the mentioned purpose, first, the flow penetration through different porous medium arrays is compared; then, effect of hydrophobicity on penetration is studied. Finally, the leakage flow rate of various arrays is investigated. The results indicate that utilizing a combined porous medium can drastically reduce the penetration and leakage. This optimized configuration has lower porosity in underneath part. Also, result show when the surface is hydrophobic, the penetration of fluid through the porous medium is slower, compared with the hydrophilic surface.
Seyyed Abbas ArhamNamazi, Nasrollah Banimostafa Arab, Amir Refahi Oskouei, Francesco Aymerich,
Volume 18, Issue 3 (5-2018)
Abstract
Nowadays, the use of polymer composite materials in various industries has been increased due to their good mechanical properties, lightness, sound and thermal insulation and corrosion resistance. Over the past two decades, carbon fiber reinforced polymer (CFRP) materials have been widely used in aerospace and automotive industries. These materials may be subjected to impact during manufacturing or service period and a lsmal impact region may be produced in them. This small defect can reduce the mechanical properties of the structure and lead to its failure. Therefore, it is necessary to use a method for defect detection in these materials. In this study, a polymer composite sample made of carbon fiber in polyester resin was made and subjected to impact test. To consider the repeatability of the defect detection process, the sample was subjected to four various impact tests and the defect areas were evaluated using penetrant-enhanced X-ray radiography and ultrasound immersion pulse-echo C-scan. The image obtained from the penetrant-enhanced X-ray method was scanned using a digital scanner, and the image of the ultrasound C-scan test was calibrated, taking into account the step of scanning.The areas of the defect region were obtained using Imagej software. The results show that these methods are able to detect and measure the impact area in the composite sample and Ultrasonic C-scan method detect impact area more accurately.
Volume 18, Issue 113 (july 2021)
Abstract
Today, increasing attention is paid to natural antioxidants and preservatives, including plant extracts. The aim of this study was to identify the functional groups of bioactive compounds, antioxidant activity, total phenol and total flavonoids of ethanolic, aqueous and hydroalcoholic extracts of red bell pepper. Red bell pepper extracts were extracted using ethanol, water and a mixture of water and ethanol (50-50%), respectively. Factor groups were qualitatively identified and investigated by Fourier transform infrared spectroscopy (FTIR). Total phenol was calculated using Folin-Ciocalteu reagent and the number of total flavonoids was calculated by aluminum chloride colorimetry. The antioxidant activity of red bell pepper extracts was evaluated by DPPH and ABTS free radical scavenging tests and the decay of color of beta-carotene/linoleic acid. The presence of C-C and OH groups of polyphenolic compounds of red bell pepper extract was confirmed by FTIR. The phenols of ethanolic, aqueous and hydro-alcoholic extracts of red bell pepper were equal to 22.68, 19.50 and 20.80 mg GAE / g, respectively. The flavonoid content of ethanolic, aqueous and hydro-alcoholic extracts were calculated to be 39.30, 29.28 and 33.70 mg QE / g, respectively. Antioxidant capacity of red bell pepper extracts based on radical scavenging activity of DPPH, ABTS and decay of color of beta-carotene/linoleic acid, 53.39, 59.38 and 56.88 percent for ethanolic extract, 46.37, 51/28 and 48/20 percent for aqueous extract and hydro-alcoholic extract were 51, 57.66 and 49.60 percent. According to the results, it seems that ethanolic, aqueous and hydroalcoholic extracts of red bell pepper can be used as antioxidants and natural preservatives in the food industry to prevent oxidation of food products.
Volume 21, Issue 149 (July 2024)
Abstract
Probiotics are non-pathogenic and beneficial bacteria that contribute to improving digestive health, preventing various types of cancer, and boosting the body's immune system, among other benefits. The aim of this study was to investigate the probiotic potential and antimicrobial activity of the strain Lacticaseibacillus rhamnosus JCM 1136. In this research, the probiotic and safety characteristics of the strain were assessed, including acid resistance at pH 2, 3, and 4, bile resistance (0%, 0.3%, 0.5%, and 0.7% bile salt concentration), hydropHobicity, potential for producing DNase enzyme and biogenic amines, hemolytic activity, antioxidant activity, cholesterol absorption capacity, and resistance to common antibiotics. The antimicrobial effect of the strain against pathogenic bacteria (Shigella dysenteriae, Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, Listeria innocua, and Bacillus cereus) was evaluated using the agar well diffusion and disk diffusion methods. The results showed that L. rhamnosus JCM 1136 exhibited survival capability at different pH levels. The growth of the strain decreased with increasing bile salt concentration. L. rhamnosus JCM 1136 showed intermediate to the antibiotic Ampicillin and sensitivity to other antibiotics. The hydropHobicity, antioxidant activity by DPPH and ABTS methods, and cholesterol absorption capacity of the strain were 50.0 ± 50.53%, 50.0 ± 23.44%, 62.0 ± 50.48%, and 43.0 ± 55.41%, respectively. No production of DNase enzyme, biogenic amines, or hemolytic activity was observed in the strain. L. rhamnosus JCM 1136 exhibited a greater antimicrobial effect against Gram-positive bacteria. The results indicate that L. rhamnosus JCM 1136 possesses desirable probiotic characteristics and can be used in the production of probiotic food products.
Volume 21, Issue 153 (November 2024)
Abstract
In this study, molecular identification of Lactiplantibacillus pentosus v390 was performed using 16S rRNA gene analysis with FYM27 and R1492 primers. The viability of the strain was assessed under acidic conditions at pH 5.2, 5.3, and 5.4, and resistance to bile at concentrations of 0%, 3.0%, 5.0%, and 7.0% was investigated. Antioxidant activity, cholesterol absorption, hydrophobicity, potential for DNase enzyme production, biogenic amines, hemolytic activity, and resistance to common therapeutic antibiotics were evaluated. The antimicrobial effect of the strain against pathogenic bacteria (Shigella dysenteriae, Salmonella enterica serovar Typhimurium, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Bacillus subtilis) was examined using the well and disk diffusion method. The results showed that the L. pentosus v390 strain had the ability to survive at different pH levels, but after three hours of storage at pH 5.2, the bacterial count decreased. The strain demonstrated growth capability at various bile salt concentrations. L. pentosus v390 was intermediate to the antibiotic Nitrofurazone, resistant to Nalidixic and Imipenem antibiotics, and sensitive to Vancocin, Gentamicin, Chloramphenicol, Penicillin, and Ciprofloxacin antibiotics. The hydrophobicity, antioxidant activity (DPPH and ABTS), and cholesterol absorption of the strain were 38.0 ± 50.46%, 40.0 ± 20.37%, 45.0 ± 9.39%, and 47.0 ± 50.36%, respectively. No DNase enzyme production, biogenic amines, or hemolytic activity were observed from the strain. L. pentosus v390 exhibited stronger antimicrobial effects against Gram-positive bacteria. The results indicated that L. pentosus v390 has desirable probiotic properties that require further research to confirm its application potential in food product development.