Search published articles


Showing 45 results for Akbarzadeh


Volume 1, Issue 1 (2-2016)
Abstract

Background: Musculoskeletal disorders (MSD) represent one of the most frequently occurring and costly occupational issue in nursing. The nursing profession is one of the most stressful occupations today, because of the quantity and diversity of risk factors associated with the work environment. The aim of this study was to examine the relationship between burnout syndrome and musculoskeletal disorders. Material and Methods: In this cross-sectional study a questionnaire survey was carried out among 415 nursing personnel in five educational hospitals in Hamedan, Iran. Data were collected through two unnamed questionnaires including Maslach Burnout Inventory, Visual Analogue Scale (VAS). Results: Statistical analysis showed that the most commonly painful regions among the nurses were lower back (5.53%), left foot (5.08%), and head and neck (4.43%), right foot (4.90%), right knee (3.84%) and left knee (3.74%). The lowest pain, were found to be in right and left elbows (1.99%) and (1.91%), respectively. Also emotional exhaustion, depersonalization and personal accomplishment has significant correlation with musculoskeletal disorders (P = 0.000, r = 0.122). Conclusions: The results showed high prevalence of MDS among Iranian nurses that could be due to emotional exhaustion and depression.  

Volume 6, Issue 2 (9-2016)
Abstract

Supplier development refers to the purchaser activities to improve supplier performance in the areas of quality, cost, time of ordering to delivery, service, reliability, and promotion of suppliers knowledge which positively affects the operational and business performance of purchaser. The present study deals with suppliers' development strategies including enhancement of suppliers’ quality improvement systems, data exchange with suppliers in the areas of quality, suppliers’ process improvement, suppliers’ productivity enhancement and contribute to the development of the suppliers’ product by the Balanced Scorecard (BSC) approach, Analytic Network Process (ANP) and Revised Decision Making Trial and Evaluation Laboratory (Revised DEMATEL) techniques. The population of the current research consists of the foundry companies having more than 200 subject as human resources in Iran which manufacture the automobile parts. The research findings have shown that financial perspective (0.5417) ,  learning and growth perspective (0.0688) are respectively the most important and the least important dimensions to improve organization performance. in addition , information exchange with suppliers in the areas of quality (0.30) and suppliers' productivity increasing (0.11) are respectively the most and least important strategies in suppliers' development.

Volume 8, Issue 2 (Number 2 - 2006)
Abstract

Thrips species injurious to grapes are known as pests in vineyards all over the world and belong to the main pests of grapes in West Azarbaijan, Iran. In this study, thrips species occurring in West Azarbaijan vineyards were identified and the predominant species documented according to their relative abundance at different growth stages. The seasonal abundance of predominant species was investigated by means of yellow sticky trap catches and weekly sampling from vegetative and reproductive organs of vines. Five species including: Rubiothrips vitis (Priesner), Thrips tabaci Lindeman, Tenothrips discolor (Karny), Tenothrips reichardti (Priesner), and Limothrips angulicornis Jablonowski, were collected and identified. R. vitis, constituting 92 and 66 percent of the thrips population on vegetative and reproductive organs, respectively, was found to be predominant. T. tabaci was not found on vegetative organs, but it was found to constitute 32 percent of the thrips found on reproductive organs (flowers). The two species R.vitis and T. reichardti are new records for the Iranian fauna. The number of adult thrips caught by sticky traps was positively correlated with the density of the adults on vegetative (buds and leaves) and reproductive (flower) organs in the first and second generations, respectively.

Volume 9, Issue 1 (Winter 2020)
Abstract

Aims: Monitoring of the fish biomass is one of the basic principal of fisheries management, but ornamental and reef fish stocks, because of difficulty of estimating their abundance, have been less studied than others. The aim of this study was to estimate the standing biomass of ornamental and reef fishes in Larak Island, in the Strait of Hormuz.
Materials &Methods: Standing biomass of the fish species was assessed seasonally using Underwater Visual Census Method (UVCm) in coral reefs and  mesophotic coral reefs in Larak Island throughout 2018 and 2019. Two popular methods in UVCm (belt transect and stationary point) were used based on topography of sea bottom. The confidence interval of estimated standing biomass is calculated using bootstrapping method.
Findings: The standing biomass of ornamental and reef fishes is estimated as 2522.18, 5222.17 and 1325.15(Kg.) in Site 1, Site 2 and Site 3, that are located in 3-15meters depth. The standing biomass at Site 4, was estimated as 884.13kg. The minimum were observed in summer, also the result showed  that the standing biomass in summer was significantly lower than other seasons (P <0.05). In addition, the temporal diagnostic test showed that population structure of fish in the spring, autumn, and winter seasons was similar but significantly different from the population structure in summer.
Conclusion: The less of standing biomass in summer season can be affected  by seasonal migrations of fish in tropical and subtropical waters to deeper waters, in order to trade of the stresses caused by temperature fluctuations.
 

Volume 9, Issue 2 (Spring 2020)
Abstract

The aim of the present study was to identify the phytoplankton species which producing domoic acid and okadaic acid toxins in coastal waters of Banar Abbas city, and to determine the concentration of domoic acid and okadaic acid toxins in water and shellfish samples.Water sampling was performed in winter 2015 and summer 2016 from coastal areas overlooking the discharge of municipal and industrial effluents. Shellfish were collected from the coasts of Bandar Abbas and Bandar-e- Lengeh. Phytoplankton toxins were measured by kit method and instrumental analysis based on ELIZA method.Pseudonitzschia delicatissima, Pseudo-nitzschia pungens and Pseudo-nitzschia seriata were identified in the production of domoic acid, while Dinophysis caudate and Prorocentrum Lima were recorded as okadaic acid producers in the coastal waters of Bandar Abbas. Water-soluble okadaic acid showed significantly higher concentrations than domoic acid. Instudied shellfish samples (Circenita callipyga, Barbatia candida, Telescopium telescopiumandThalessa savignyi), the measured concentrations of okadaic acid ranged from 59.8 ± 2.38 to 121.96 ± 28.25 μg / kg. This value for domoic acid was from 0.85 to 83.59 ± 38.72 μg / kg.Compared to the guideline values, the observed concentrations of okadaic acid and domoic acid toxins in the studied shellfish were lower than the allowable level.  But this value was recorded for the water-soluble domoic acid above the allowable value, which requires continuous monitoring to achieve the quantitative and qualitative pattern of phytoplankton toxins in order to support the safety of the marine ecosystem users in Hormozgan province.

Volume 10, Issue 3 (9-2021)
Abstract

Biofloc technology has mentioned as a new tool for sustainable aquaculture development and has overcome the problems of water scarcity and discharge of aquaculture effluents to the environment. In this system, nitrogenous wastes (Ammonia and Ammonium) are simultaneously recovered by bacteria and converted into microbial proteins that can be consumed by aquatic animals. The purpose of this study was to investigate the factors affecting the production of biofloc and evaluate it for use in aquaculture. The effect of different temperature levels (24, 28, 32 °C), salinity (0, 4, 8 g/l)  ,and C/N ratio (10:1, 15:1, 20:1) which are the main key factors to the formation and function of biofloc system was evaluated by using a response surface method designing. Moreover, the influence of those factors on total ammonia nitrogen, nitrite, nitrate, floc volume, protein, and lipid content of biofloc was investigated. The results showed that the temperature had a significant effect on floc volume and protein content of biofloc (P < 0.05), but it had no significant effect on other nitrogenous compounds and lipid content (p > 0.05). The protein, lipid and moisture of biofloc particles were decreased by increasing salinity significantly (P < 0.05). Also, TAN and nitrite concentration influenced by C/N ratio inversely. According to the factors Optimization, providing 27 °C and C/N ratio of 18:1 in brackish water and 29 °C and C/N ratio of 14:1 in fresh water resulted in high quality biofloc production and control of nitrogenous wastes in water.

Volume 10, Issue 4 (12-2021)
Abstract

 This study was conducted to investigate the possible effects of cages culture Asian sea bass fish (Lates calcarifer) on the population structure of macrobenthos in the Rigo area of Qeshm Island in Hormozgan province during a breeding period in 1397 were investigated. The average abundance of macrobenthos at the location of the cages culture and the refrences site in this study was equal to (52765 ± 19154 in m2) and (50642 ± 21002 in m2), respectively.The results showed that at the time of the study among the identified the genus of Ammonia sp. With a relative abundance of 73.41 percent at the location of the cages compared to the control station and Archasterope sp., Spirolochulina sp. and Nephtys sp. with a relative abundance of 63.9%, 49.1% and 12.6%, respectively, were more dominant in the control station compared to the location of the cages.The loading rate of organic matter in the bed of the cages was significantly affected by fish farming activities and in some times showed a significant difference with the control station (P<0.05). In general, at the time of the study, activities related to fish farming in cages had no effect on the population structure of macrobenthos in the study area.


Volume 12, Issue 1 (12-2022)
Abstract

 In this study, the possible impact Asian sea bass fish (Lates calcarifer) cages culture on the population structure of phytoplankton in the coastal waters of Qeshm Island.Water sampling was done monthly for a period of six months in three stations from October 2018 to March 2019.The results showed that the mean Variations of total abundance of phytoplankton at the location of fish cages culture compared to the Reference station had a significant increase (P <0.05). At the location of cages culture, the Trophic status level was high (<5), the risk of eutrophication status (<4) and the value of trophic efficiency coefficient were high. According to the analysis of Simper test, Among the Forty-one genera identified, Noctiluca sp. with a relative abundance of % 82.37, contribution rate of 21.8% with high algal bloom at the location of cages in autumn season and then the genera Chaetoceros sp., Nitzschia sp. and Coclodinium sp. with a relative abundance of less than 10 percent in differentiating the population structure of phytoplankton have played a significant role in the dissimilarity of the population structure of phytoplankton between stations In general, in this study, the effects of fish farming activities on the population structure of phytoplankton are ineffective, but it causes the abundance of some species, available nutrients, increases the trophic level, and the probability of harmful algal blooms in the location of the cages culture.
 

 

Volume 12, Issue 2 (4-2023)
Abstract

Annually, millions of rainbow trout frys are produced in Iranian hatcheries, however, millions of selected stocks of rainbow trout eyed eggs are also imported for breeding in farms. Despite the interest of many rainbow trout farmers to use imported fish for breeding, there is no clear information about the superiority of growth and survival of these imported strains over the rainbow trout that are produced in Iranian hatcheries. For this purpose, in the present study, the growth parameters of 432 individuals of either imported Spanish and Iranian strains of rainbow trout reared in 12 ponds using both river and spring water sources (four treatments and three replicates) were investigated and compared for 90 days. At the end of the experiment, a significantly higher weight and length gain, and specific growth rate was observed in Spanish rainbow trout compared to Iranian strain in both water sources (river and spring) (p < 0.05). Moreover, the food conversion factor was significantly lower in Spanish strain than Iranian rainbow trout) (p < 0.05). These results showed that the selection breeding could remarkably enhance growth performance and consequently cause more production and profit for rainbow trout farmers.

Volume 12, Issue 3 (9-2023)
Abstract

The present study was conducted in order to obtain the necessary information on the diversity, abundance and distribution of macroinvertebrates, as well as to investigate the grazing status of batoid fishes (stingrays) from benthic macroinvertebrtes in coastal waters of Hormozgan province. For this purpose, sampling was done in the years 2017 and 2018 and once every year in the autumn season. At the end of the identification process, a number of 125 genus and 104 species belonging to 85 families, 31 classes, 9 orders, and 7 phyla were successfully identified. Results revealed that Malacostraca was the frequent order in the studied area. In order to investigate the possible relationship between composition and abundance of benthic macroinvertebrte and stingrays, CCA analysis was employed. Results of stomach content of stingrays revealed that in the diet of M. randall, crustacean (93.25 %IRI) has the highest amount. This pattern was the same for M. gerrardi and H. walga. However, in M. gerrardi, bivalvia were in the first place of importance (31.33 %IRI). Also, trophic level analysis was done for three species which shows all species are Mesopredators that place in the same level of food web. According to the mentioned cases, some benthic macroinvertebrates identified in this research have a significant  relationship with the benthic fishes, which requires more studies to investigate their relationship.
 

Volume 13, Issue 1 (Winter 2025)
Abstract

Aims: Occupational illnesses remain a pressing concern for workers exposed to hazardous materials in industrial settings. While Personal Protective Equipment (PPE) serves as a primary safeguard against such risks, its inconsistent utilization highlights critical gaps in understanding the determinants of PPE compliance. This study investigated personal and situational factors influencing PPE usage among employees handling organic solvents in three major industrial companies.
Methods: A cross-sectional survey of 340 workers was conducted, employing the Health Promotion Model (HPM) as the theoretical framework to identify predictors of PPE utilization. Data were analyzed using chi-square tests, t-tests, and two-level logistic regression.
Findings: Results revealed that only 47.9% of workers regularly used face masks, while 67.4% wore gloves, signifying substantial non-compliance. Among the HPM components, interpersonal factors, such as trust, mutual respect, and collegial relationships, were significantly associated with PPE adherence. Additionally, organizational factors, including workplace policies and support systems, strongly correlated with the use of protective gloves. These findings underscore the critical role of fostering interpersonal relationships and implementing robust organizational policies to promote PPE compliance.
Conclusion: The study demonstrates the applicability of the HPM in understanding PPE compliance within industrial settings. While the research was conducted in companies located within the same city, the findings emphasize the significance of interpersonal and organizational factors in promoting PPE usage. By offering actionable insights, this study provides a foundation for developing targeted interventions aimed at improving PPE adherence, ultimately reducing workplace-related health risks and enhancing worker safety.

Volume 13, Issue 3 (8-2010)
Abstract

Objective: Prostate cancer is one of the most common cancer in the developed countries. Most of cancer deaths are due to development of metastasis. Hence, prevention of metastasis is critical. Silibinin is a flavonoid component that inhibits cell proliferation and causes cell death of human prostate cancer. In this study, the expression of CD82 gene in PC-3 cells treated with escalating concentrations of silibinin was evaluated which can result in new view for prostate cancer therapy. Materials and Methods: In this study, PC-3 cells were treated with different concentrations of silibinin for 24h. The LD50 was determined. RNA was extracted by trizol, then cDNA was synthesized. Precise primers were designed for CD82 and GAPDH genes by specific software. Quantity of CD82 gene expression compare to GAPDH gene in different concentrations of silibilin was analyzed using very sensitive quantitative Real-time PCR. Results: CD82 gene expression in PC-3 cells treated with 100, 150 and 200μg/ml of silibinin at 24h was increased by 1.97±0.26 (P<0.05), 3.00±0.26 and 3.43±0.43 (P<0.01), respectively. Conclusion: The results of quantitative Real-time PCR indicated that silibinin can probably decrease metastasis, by up-regulation of CD82 metastasis suppressor gene in PC-3 cells.

Volume 13, Issue 4 (11-2024)
Abstract

The dramatic increase in heavy metals, their stable nature, and high toxicity, is gradually becoming a global crisis. In a recent study, a comprehensive assessment of the spatial distribution of heavy metals including Cd, Pb, Ni, Cu, Zn, and Cr was performed in industrial and commercial areas, including the sediments of 32 stations located in the area of Jask, Bandar Abbas, Qeshm, and Bandar Lange during the 2021to 2022. In this area, the concentration of heavy metals showed significant spatial variations between the areas. The maximum concentration of Cd was 0.55 μg/g in the first station of Gasheh. The second station of Khor Langeh had the highest Pb concentration with an average of 10.25 μg/g. The maximum concentration of Cr was 2420.33 μg/g in the second Shahid Bahonar station. The highest Zn concentration of 268.56 μg/g was observed in the first station of Suru beach. In the first station of Shahid Rajaei port, the highest concentration of Cu was observed at 18.36 μg/g. The maximum concentration of Ni was 519.02 μg/g in the second station of Shahid Bahonar.The stations located in Shahid Bahonar port, Suru beach, and Khor Gorsouzuan had a higher pollution intensity than other places and significant pollution risks, especially in terms of Cr, Ni, and Zn. In these areas, Cr was identified as the most dangerous metal. It is necessary to consider comprehensive strategies to control and reduce these heavy metal pollutions, to identify and manage the sources of these pollutions.
 


Volume 14, Issue 2 (3-2012)
Abstract

Grape berry moth, Lobesia botrana (Denis and Schiff.) is a destructive pest of grapevine in Orumieh (Northwest, Iran) vineyards. It is mainly controled through application of broad-spectrum insecticides, which can adversely affect vineyard ecosystem and consequently human health. Since a first step in setting up an IPM program is to assess the biological control agents within the ecosystem, so in this research work the larval parasitoid complex of Grape Berry Moth (GBM) on vine was identified, and its natural potential in controlling the pest compared for different generations and in different locations in Orumieh during 2004-2006. Adults of the larval parasitoids of GBM were recorded from laboratory-reared larvae, which had been collected on damaged inflorescences of the first generation and berries of the second and the third generations. Rate (%) of parasitism on L. botrana larvae was estimated as the number of parasitoids over the total count of parasitoids and moths. Six larval parasitoids of the host were found: Enytus apostata Gravenhorst, 1829; Pristomerus vulnerator (Panzer, 1799); Temelucha sp. (Hymenoptera: Ichneumonidae), Nemorilla maculosa (Meigen, 1824) (Diptera: Tachinidae), Habrobracon hebetor (Say) and Bracon sp. (Hymenoptera: Braconidae). Total parasitism varied from 1 to 16.8%, with an average of 7.7% as revealed through the present study. A comparison of the means of the larval parasitism rate showed a significant difference at 5% level between different generations and localities. The highest rate of parasitism occurred in the first generation in all localities, as well as in years.

Volume 14, Issue 3 (2-2024)
Abstract

  The use of productive microorganisms in the production of primary and secondary metabolites is part of the knowledge of microbial biotechnology, which is carried out with the aim of using huge cellular factories and considering their inherent and latent ability to produce products. Investigating and optimizing the factors affecting the synthesis of metabolites will increase the growth of the strain and the yield of the product. In this regard, in this research, by using the response surface method (RSM) and Box-Behnken design, the fermentation production of cephalosporin C by Acromonium chrysogenum PTCC 5271, and the effect of three factors on the fermentation process, including pH of Fermentation culture media, rice bran and magnetite iron oxide nanoparticles have been measured at three levels. The obtained results showed that changes in the concentration of magnetite iron oxide nanoparticles and rice bran in the fermentation media significantly affect the amount of antibiotics produced. The highest amount of Cephalosporin C produced (224 mg/l) was obtained in the culture containing 0.04 mg/l magnetite iron oxide nanoparticles, 2.5 g/l rice bran and pH of 6.5. The optimized values ​​for the factors were calculated as 0.0325 mg/l, 2.6162 g/l, and 6.4545 respectively by the Mini Tab program, and finally the mathematical model for the response variable was obtained. Based on the results of this research, magnetite iron oxide nanoparticles and rice bran are suitable substrates in fermentation culture media and biological processes.
Pooria Akbarzad, Iraj Mirzaee, Mohammad Hassan Kayhani, Ebrahim Akbarzadeh,
Volume 14, Issue 4 (7-2014)
Abstract

Effect of boundary layer and its local separation on lift and drag coefficients, especially in the analysis of hydrodynamic behavior of hydrofoils is considered as an interesting subject for fluid mechanics researchers. Boundary layer control methods to increase the lift coefficient and reduce the drag coefficient, are very common. Aerodynamic study of flows at low Reynolds to special applications such as micro unmanned underwater vehicles, underwater robots and explorers are interested. For this reason in this study, the effect of fluid blowing and suction through upper surface of hydrofoils on flow control, lift and drag coefficients for flow under Re =500 and Re=2000 are investigated. Jameson’s finite volume method and power-law preconditioning method for analyzing viscous incompressible flows are presented. To control the boundary layer a jet with a width of 2.5% of chord length is placed on hydrofoil’s upper surface and results for different blowing (suction) parameters are introduced. Results show that, blowing far from leading edge at low blowing angel and perpendicular suction far from leading edge increase the lift coefficient. Also blowing with law velocity ratio and suction with large velocity ratio, has the better impact on increasing lift coefficient.
Saleh Akbarzadeh, Morteza Parsa,
Volume 14, Issue 7 (10-2014)
Abstract

Gears are widely used to transmit power between two parallel shafts. Study on the lubricant film which is formed between the engaged teeth of pinion and gear is of high importance in predicting the performance of the power transmission system as well as surface failure and wear. Gear surfaces in comparison to rolling element bearings have a higher surface roughness and thus considering the surface roughness is important in gear analysis. In this research, the performance of a pinion-gear system operating under mixed-elastohydrodynamic lubrication is being investigated using load-sharing concept. The contacting asperities might experience elastic, elasto-plastic or fully plastic contact. The engagement of pinion and gear for each point along the line of action is replaced with contact of two cylinders. The radii of these cylinders as well as the exerted load vary along the line of action. Using load-sharing concept, the proposed model can predict the lubricant film thickness, friction coefficient, and portion of the total load that is carried by asperities as well as lubricant film. The predicted results are verified by comparison to other available methods which are published in the literature.
Pooria Akbarzadeh, Ebrahim Akbarzadeh,
Volume 14, Issue 8 (11-2014)
Abstract

Numerical analysis and simulation of cavitating flows due to appearance and its application in the maritime industry, water turbomachinery, hydrofoils, underwater vehicles, etc. have specific importance. For this reason in this research, the effect of blowing on hydrodynamic behavior of cavitating flows over hydrofoils has been investigated. Jameson's finite volume method and power-law preconditioning method with single-phase cavitation model (Barotropic model) have been used to the analyzing of cavitating flow. The stabilization of solution has been achieved with help of the second and fourth-order dissipation term. Explicit four step Runge-Kutta method has been used to achieve the steady state condition. As regards the cavitation often occurs at high Reynolds number, to facilitate the simulation the inviscid flow equations are considered. For apply the blowing from hydrofoil surface, a jet has been placed on hydrofoil’s upper surface. The parameters of jet location, blowing velocity ratio, blowing angle and width of jet are investigated and simulation has been performed for two different cavitation numbers. The numerical results show that the power-law precondition increases the convergence speed significantly. Blowing reduces the cavity length, lift and pressure drag coefficients compared to no blowing case. Also the increase of blowing velocity ratio, blowing angle and width of jet, decrease the cavity length, lift and pressure drag coefficients.
Saleh Akbarzadeh, Abolfazl Ebrahimi Serest,
Volume 14, Issue 10 (1-2015)
Abstract

Gears are one of the most important elements of any power transmission system. Among all types of gears, helical gears are more common due to their high capacity in power transmission as well as lower level of noise. The aim of this study is to present a model for analyzing the contact of teeth of helical gears considering thermal effects and surface roughness. In the present model, each helical gear is divided to several narrow spur gears in which each of the spur gears have a small rotation angle relative to the previous one. Also each contact point of gears is replaced with contact of two equivalent cylinders. Considering the fact that the governing regime for gears lubrication is the mixed-elastohydrodynamic regime, the total load is carried by lubricant and asperities' contact. Meshing and lubrication analysis of a pair of helical gears is conducted based on the load-sharing concept and parameters such as film thickness, friction coefficient and temperature rise are predicted. The predictions based on the load-sharing concept are compared to other published results Acceptable accuracy, short execution time along with considering thermal and roughness effects are some of the major characteristics of this study.
Mohammad Mahdi Samandari, Karen Abrinia, Abbas Akbarzadeh,
Volume 14, Issue 15 (Third Special Issue 2015)
Abstract

Spin-bonding is a method for fabrication of bilayer tubes based on flow-forming process. This new method is a process with high potential in production of seamless thin-walled tubes. Utilizing this process, aluminum tube (as the inner layer or clad layer) has been bonded into steel tube (as the outer layer) to fabricate tubular laminate composites. As important parameters for creating a suitable bond, effects of thickness reduction, initial aluminum thickness and strength on bonding strength were investigated. The bond strength was evaluated by peel test and the peeled surfaces were examined using scanning electron microscopy (SEM). The results indicated that thickness reduction has great influence on strength and quality of the bond. After a threshold reduction (about 35%) the bond strength increases rapidly with the amount of deformation, until it approaches the weaker metal strength, and samples fracture from the base metal in the peel test. Approaching the strength of the two metals and decreasing the initial thickness of the clad layer, with a high amount of deformation increased the bonding strength. Fracture surface images showed that the surface fraction of bonding area was increased when deformation increased. It was also increased with the reduction of the initial thickness of the clad layer and when the strength of the two layers approached each other. Additionally, distribution and shape of the fracture area changed from a disordered fibril structure to approximately straight area, with an increase in the deformation.

Page 1 from 3    
First
Previous
1