Showing 16 results for Kazemian
Volume 2, Issue 2 (4-2016)
Abstract
Background: Helicobacter pylori is the most common cause of chronic infection in the human stomach. The infection has universe prevalence in all age groups. Probably, this bacterium is the cause of most common chronic bacterial infection in human beings and infects approximately half of the world population. H. pylori produces urease, an enzyme that degrades the urea in the stomach’s mucous to ammonia resulting in biochemical reaction that leads to increase in pH of the stomach lumen. This allows pathogenic intestinal protozoa to take the opportunity to cross through stomach’s increased pH and cause disease. The aim of this study was to evaluate the relationship between H. pylori infection and prevalence of parasitic infection in patients in Ilam. Materials and Methods: Following stool samples collection during 2013 in patients with abdominal pain in Ilam, Iran. H. pylori infection was investigated based on stool antigen analysis (HPSA) by enzyme-linked immunosorbent assay (ELISA) method in patients who had recurrent abdominal pain. Stool specimens were examined using the direct examination and the spontaneous sedimentation method for detecting the trophozoite and cyst of parasites. Results: In this study, we found 65 patients with H. pylori infection. Out of these 65 patients, the percentage of patients with positive results for Giardia lamblia was 30.7% and for Entamoebahistolytica/dispar was 12.3%. Conclusion: The results of this study suggest that H. pylori infection may provide favorable conditions for giardiasis infection; however, this presumption needs further studies with larger sample size.
Zahra Mahmoudi, Mohammad Kazemian, Eghbal Khajehrahimi,
Volume 11, Issue 1 (3-2022)
Abstract
The long nose sturgeon (Acipenser stellatus, Pallas, 1771) is an anadromous sturgeon species, yet little is known with regard to salt bath effect on bacterial adhesion on superficial organs of this species and its growth. This study was conducted to determine the optimal salt bath concentration on growth parameters and total bacteria count on juvenile stellate sturgeon gill and skin. A total of 200 fishes with mean initial weight 494.5 ± 2.17 g and length 62.63 ± 0.18 cm (mean ± SD) were randomly distributed into 12 concrete pools in groups of 25. Fishes exposed to acute salinity of 0, 5, 10, and 15ppt for 30 minutes. Salt bath is used 5 times for 60 days (1, 15, 30, 45 and 60). At the end of 60th day, growth indices including body weight, SGR, BWI, ADG, PER and FE revealed a significant increase at 5ppt salinity (P< 0.05) and fishes exposed to 15ppt exhibited the poorest growth. No statistical significant difference was observed between control and other treatments in total protein and albumin, also in total bacteria count in gill and skin of fishes (P>0.05) but higher levels of total protein and albumin and lower level of total bacteria observed in 5ppt treatment. The results of this study indicate that high acute salinity may compromise the growth of juvenile long nose sturgeon and suggest that, in commercial operations, salinity should be 5ppt.
Volume 12, Issue 4 (Winter 2023)
Abstract
Aims: The purpose of this study is to investigate the role of vegetation in reducing nuisance wind speed on the Imam Street sidewalk. Imam Street is one of the main arteries in Tabriz, and the nuisance wind speed on its sidewalks disturbs the climate comfort for pedestrians, especially during the cold season.
Methods: A descriptive-analytical method is used in this study, and numerical simulations are performed using Dlubal RWIND 2.02 to evaluate the wind flow for the current condition and the proposed alternatives. In this context, the effect of vegetation height, spacing and arrangement (with tree bench) as independent variables on wind speed at pedestrian height as dependent variable was investigated. Spearman correlation test is used to evaluate the relationship between variables.
Findings: The studies have shown that trees with a height of 4 meters, distributed at a distance of 5 meters according to the pattern 1, can reduce the flow velocity on the pedestrian level by 52%.
Conclusion: The results show that the implementation of vegetation in appropriate spacing and pattern can significantly reduce wind speed. Placing tree benches on the sidewalk changes the airflow toward the street and reduces wind speed at the pedestrian level.
Volume 13, Issue 2 (Fall & Winter 2009)
Abstract
City central district, where the most important events of a city take place, has different features in different cities according to the specific conditions of that city. However, in spite of the significance of this district in the city space, the researches in this field have been done with an emphasis on big cities and mainly for problem-solving purposes.
In this study, therefore, a framework consisting of economic (land and shopping value, employment density and distribution of financial, insurance and social security institutions), historical (the historic core of the city, stages of city development and symbolic elements of the city), social (public spaces of the city, density of cultural centers, population density, population density in certain parts of the day), traffic (centeral place for traffic, transport station density of city and accessibility), governmental (activity of governmental and public office centers) and physical- spatial factors (building density, historic fabric, specific architecture, urban development pattern and land use pattern), was presented. Through analyzing the urban space of Bookan, as an intermediate city located in Iran, the role of the
above-mentioned factors in the development of its central district was investigated. Then, the major factors contributing to the explanation of this district were identified.
The results showed that, among the set of factors influencing the central district historic and economic factors, were the most important ones in Bookan;on the other hand, the governmental function has been decentralized, and functional and activity variances are the major features of city central district of Bookan compared to other parts of the city. Our findings also show that the central district of Bookan city include the most important activities of the city; therefore, by including wide range of different activities it has different functions and, thereby, its boundary basically differs from that of other parts of the city from this perspective.
Volume 16, Issue 1 (Spring 2016 2016)
Abstract
Employees in the informal sector of the Iranian economy suffer from lack of access to various health insurance services. This research tries to assess the development of arbitrary health insurance schemes and households’ willingness to pay for health care premium for the low-income employees in the informal sector, totally aiming at universal coverage for the insurance scheme. This research is of statistical- analytic type, which uses contingent valuation questionnaire to estimate households’ willingness to pay for arbitrary health care premium subject to government financial contribution. To do this, it applies record data over the period 1987-2009. The regression analysis is used to determine households’ health care premium and public sector contribution. The research estimates the premium of the arbitrary health care insurance for the urban households in the first three deciles and determines the government contribution to this scheme. The estimated elasticities show that reduction in the government share in health care premium increases the effect of social- economic variables on households’ willingness to pay for health care premium. To achieve universal coverage in the arbitrary health insurance scheme for the low-income group requires providing appropriate data on variables affecting households’ willingness to pay through contingent valuation questionnaire. In addition, the administrative system for social health care insurance should be developed to the extent that low-income households can get access to insurance administrative services, and receive full information about annual households’ income and health expenditure, public sector contribution and monetary value for the arbitrary health insurance services.
Volume 17, Issue 6 (12-2017)
Abstract
Acting as a surface which is supposed to tolerate several reloading of heavy axes, pavement shall hold enough resistance against failures. Fatigue phenomenon is one of the most important causes of weakness in road pavement, which is occurred due to reloading of it. Many laboratory researches are carried out with the purpose to enhance fatigue life of asphalt concrete mix, in which researchers have tried to improve quality of asphalt concrete mix against load carrying transportation vehicles. During recent years, additives like polymer, iron powder, hydrated lime, glass wastages, crumb rubber and brick powder are also considered for improving tar and, consequently, asphalt mix properties. Generally, hot-mix asphalt (HMA) mixtures consist of three components: mineral aggregates, asphalt binder and air voids. It is well recognized that mineral fillers play an important role in the properties of mastics and hot-mix asphalt (HMA) mixtures. Better understanding of the effects of fillers on the properties of mastics and HMA mixtures is crucial to good mix design and high performance of HMA mixtures. In this stydy, the effect of brick powder on fatigue parametrs have been investigatedFiller content for mix design should be determined based on the overall performance of HMA mixtures.It has been recognised with growing concern that agricultural and industrial wastes are increasingly produced in large volume. In order to reduce environmental hazards and conserve natural resources, the use of waste materials in highway pavements would be extremely effective in terms of recycling waste materials. The main purpose of this study was to investigate the effects of waste materials as filler on the performance of hot mix asphalt (HMA) mixtures.It is well recognized that mineral fillers play an important role in the properties of mastics and hot-mix asphalt (HMA) mixtures. Better understanding of the effects of fillers on the properties of mastics and HMA mixtures is crucial to good mix design and high performance of HMA mixtures. Laboratory experiments were conducted to investigate the effect of different fillers on properties of mastics and HMA mixtures. The properties of HMA mixtures were investigated by Marshall, indirect tensile stiffness modulus and indirect tensile fatigue tests. The results indicated that WBP mixtures exhibited higher fatigue life and better performance than control mixtures. With the increase of filler content, some properties of HMA improved while others decreased. The effects of filler were exerted on HMA mixtures through the mastic. Fillers with rough particle texture (such as manufactured sand) tend to increase the stiffening effect of the mastics and mixtures. Considering the overall effects of filler on the properties of HMA mixtures, a filler content range would be required in order to ensure the performance of the mixtures. Waste materials can be mainly regarded as the following classifications: (a) industrial wastes such as cellulose waste, slag, bottom ash and fly ash; (b) municipal/household wastes such as incinerator residue, scrap rubber and waste glass; (c) mining wastes such as coalmine refuse and (d) construction and demolition Based on the results, in consequence of increased awareness of environmental issues and natural resources constraints, the studied waste materials can be advantageously utilised in road construction.
Volume 17, Issue 11 (1-2018)
Abstract
In this study, the effects of using pure water, water/ethylene glycol mixture with 50:50 wt% and pure ethylene glycol as the working fluids on the energy and exergy efficiencies of a photovoltaic thermal (PVT) system are experimentally investigated. Moreover, the performance of the PVT systems are compared with a conventional photovoltaic (PV) system. The experiments are performed on a selected day in August at the Ferdowsi University of Mashhad, Mashhad, Iran (Latitude: 36° and Longitude: 59°). The investigated parameters in this study are: the photovoltaic cells temperature; output electrical and thermal powers; electrical and thermal energy efficiencies; output electrical and thermal exergies; and electrical and thermal exergy efficiencies. Based on the results, the PVT system with water/ethylene glycol mixture increases the output electrical power by about 5.41 % compared to that of the PV system. Furthermore, the results indicate that using pure water in the PVT system enhances electrical and thermal energy efficiencies compared to those of pure ethylene glycol and water/ethylene glycol mixture, whereas the overall exergy efficiency of PVT systems with pure water and water/ethylene glycol mixture working fluids are approximately same.
Volume 19, Issue 12 (December 2019)
Abstract
In this paper, the effect of the Gurney flap parameters such as the angle of attack, Reynolds number, angle and height of the flap and its location from the escape edge on the lift coefficient of a symmetric airfoil is considered with the help of simulation in computational fluid dynamic software of Fluent. The turbulence model k-ε is used for the two-dimensional domain. Also, the value of the lift coefficient is introduced as a function of effective parameters by the design of experiment (DOE) method and using the backward elimination regression model which is a statistical method for selecting the model and estimated error terms. The value of the airfoil lift coefficient can be determined and predicted by the obtained function. The numerical values derived from the function of the lift coefficient resulted from the design of experiment method are in good agreement with other valid papers. The results show that at the constant attack angle by increasing Gurney flap height, lift coefficient increase. On the other hand, at the constant height of the Gurney flap, this coefficient decreases with increasing angle of attack. Moreover, the lift coefficient increased by increasing the distance of the Gurney flap from the airfoil escape edge at a 90-degree angle and 1.5%, as well as increasing the Reynolds number at a constant height of a Gurney flap.
Volume 20, Issue 2 (8-2017)
Abstract
Objective: Pathological changes to endothelial cells of the vessel wall may lead to vascular stenosis. In this study, we investigate damages that appear following radiotherapy in two states, single fraction and fractionation irradiation, as an effective sign of cytoskeletal and nuclei structure of vascular wall endothelial cells.
Methods: We irradiated human vein endothelial cells (HUVECs) with a Cobalt-60 therapy machine at radiation doses of 0, 2, 4, and 8 Gy. We stained the skeletal structure of the membrane and nuclei within 24 h after irradiation. This cell line received fractionation radiation therapy at doses from 0 to 8 Gy, in sub-fractions of 2 Gy, after which we stained the cytoskeleton. Morphological parameters such as area and perimeter of the cells and nuclei were determined, and we evaluated the cell shape index (CSI) for cells from each group.
Results: Increasing the irradiation dose from 0 to 8 Gy led to a significant decrease of CSI (approximately 56%) and a significant increase of nuclei shape index (approximately 85%; p<0.05). The cells’ areas and nuclei doubled (p<0.05). CSI parameter significantly decreased approximately 23% (4.5 times lower) during the radiotherapy fraction after application of the 8 Gy compared with control group cells.
Conclusion: After irradiation, we observed broken the membrane filaments that resulted in a new configuration, which led to increased cell and nuclei sizes along with alterations in the cell shape. Radiation therapy led to dose-dependent changes in morphological behavior response of the endothelial cells. Hence, it would be considered as a prognostic factor for behavior of healthy vascular cells in the process of radiotherapy.
Volume 20, Issue 142 (December 2023)
Abstract
Considering the sensitivity of fish meat to rapid spoilage, storage conditions and type of packaging are very effective factors in maintaining its quality and nutritional value after catching. In this research, rainbow trout fillets packed with aluminum and polystyrene as treatment and polyethylene bag as control were kept at 4°C for 12 days. Physical, chemical and microbial factors of fillets by recording changes in moisture, total protein, fat, total ash, free fatty acids, peroxide (PV), pH, Thiobarbituric acid (TBA), Total Volatile Basic Nitrogen (TVB-N) and also total microbial load It was measured. The results showed that with the passage of time, moisture and fat decreased significantly. Total protein, total ash, free fatty acids, PV, TBA, TVB-N and total microbial load increased significantly during storage. Also, pH had an increasing trend, but this increase was not significant. The highest amount of TVB-N on the twelfth day was related to the control package with a value of 24.52 mg/g. The lowest amount of total microbial load on the twelfth day was related to aluminum packaging with a log value of 6.86 cfu/g. According to the results, the priority of using packaging to increase shelf life and maintain the nutritional value of fillets was first with aluminum packaging and then with polystyrene. The polyethylene bag was declared unrecommended for consumption due to the lack of nutritional value and reduced product quality. Aluminum packaging worked significantly in maintaining the physicochemical and microbial properties of the product and according to the declared permissible limits of TVB-N and total microbial load, which are important indicators of spoilage, only fillets packed with aluminum containers could be consumed until the end of the storage period.
Volume 20, Issue 143 (January 2023)
Abstract
Currently, meat products are considered one of the most consumed foods in the world. The food industry is not only responsible for providing good food for the general public, but paying attention to nutritional and health-giving components such as reducing the consumption of nitrites and preservatives such as ascorbic acid is also a challenge. It is great for experts and activists in this field. This research was done to investigate the replacement of nitrite and ascorbic acid in the formulation of fish sausage. The samples are in the form of 5 treatments including C (control sample without lettuce powder and blueberry powder), T1(1%lettuce powder and 5% blueberry powder), T2 (2%lettuce powder and 5%blueberry powder), T3 (4%lettuce powder and 5%blueberry powder) and T4 (6%lettuce powder and 5% blueberry powder) blueberries) were produced. Recently, researchers are looking for the use of natural substitutes instead of nitrite in the meat industry to maintain the quality of the products to an acceptable level and to prevent their early spoilage; in this regard, many researchers use turned to plant materials as good sources of antioxidants and antimicrobials. Because blueberries are a rich source of phenolic compounds, anthocyanin, and vitamin C, they can be considered a good source of natural antioxidants. Nitrate accumulation in vegetables such as lettuce is higher than in other vegetables. It is different in different organs of vegetables, so lettuce is a good source of nitrate supply. According to the results obtained from the chemical characteristics, the T4 treatment (fish sausage sample containing 6%lettuce powder and 5% blueberry powder) was in the standard range in all the chemical characteristics of the treatment.
Volume 21, Issue 3 (5-2019)
Abstract
Developing materials to improve the efficiency of fertilizers and increase their performance is one of the main areas of research in the agricultural science. To the best of our knowledge, this is the first time that Mg-modified zeolite is used for modification of composting process of urban organic solid waste. Natural zeolite was clinoptilolite with a particle size smaller than 250 μm modified with MgCl2.6H2O salt. Different ratios (i.e. 5, 10, and 15% , on a weight basis) of natural and/or Mg-modified zeolite were used to modify the Municipal Solid Waste (MSW) compost. Experimental results revealed that the pH of the final compost product with the Mg-modified zeolite was effectively buffered at 7.7. Furthermore, in comparison to the control treatment (without zeolite), the compost with natural and Mg-modified zeolite showed 32.13 and 41.25% reduction in electrical conductivity, respectively. Ammonium retention of the compost containing 15% natural and Mg-modified zeolite was increased by 64.51 and 110.10%, respectively. Metals mobility test of the matured composts also revealed that adding zeolite, especially the Mg-modified zeolite, could decrease the mobility of Cu, Pb, Zn, Fe, Ni, and Mn metals. The most decrease in the mobility of metals was observed in Cu, which was about 44.16 and 47.82%, in the compost with the natural and Mg-modified zeolite, respectively.
Volume 21, Issue 156 (February 2025)
Abstract
Consumption of caffeine for reasons such as increasing alertness, reducing fatigue, increasing energy, and reducing drowsiness, as a drink and additive has many fans among consumers. Therefore, adding caffeine to cheese as a Dairy product containing caffeine. In addition, the consumption of caffeine causes weight loss by reducing appetite, and for this reason, its use in the formulation of food supplements has been considered. Therefore, the consumption of ultrafiltrated (UF) cheese containing caffeine, in addition to being a very good source of nutrients and useful substances needed by the children, increases energy and reduces fatigue, and makes a person more energetic. In this study, caffeine with different concentrations of 0 (control sample), 0.2, 0.4, and 0.6% was added to cheese, and its color values (L*, a*, b* indexes) and textural characteristics (hardness, cohesiveness, adhesiveness, gumminess, and springiness) were studied during the 45 days of storage period. The results of color evolution showed that the L* index decreased with the increase of caffeine concentration (p< 0.05) and passing the storage period (p< 0.001). In addition, no significant effect was observed by adding caffeine to UF-cheese on a* and b* indices, but the storage time caused a significant decrease (p< 0.01) in both parameters. The degree of hardness, cohesiveness and gumminess of the UF-cheeses decreased significantly with the increase of caffeine concentration from 0.2 to 0.6% and with the passage of storage time (p< 0.01). Adhesiveness and springiness values also decreased with increasing caffeine concentration and storage time, but these changes were not significant (p> 0.05). Based on color and texture quality, there were no significant differences between control and sample containing 0.4% caffeine. Therefore, by using the concentration of 0.4% caffeine, it is possible to produce an energizing and invigorating UF-cheese.
Volume 22, Issue 4 (6-2020)
Abstract
Cold plasma is a novel non-thermal technology for the food and packaging industry. In this study, the effects of argon glow discharge plasma on the mechanical properties, surface topography, chemical composition, film hydrophilicity, film solubility, and barrier properties of the starch films were examined. Plasma treatment improved Tensile Strength (TS) of the starch film. In contrast to TS, elongation at the break of the plasma-treated films remained unchanged. The surface roughness of starch film increased after plasma treatment. An apparent increase in the surface hydrophilicity was observed due to formation of oxygen-containing polar groups. FTIR analysis confirmed the increase in the oxygen containing groups in plasma-treated starch film. However, film surface hydrophilicity caused no significant change in the solubility of films. No significant difference was found in the barrier properties of the starch films. The evaluation of films modifications by glow discharge plasma will contribute to in-package decontamination studies of food products by plasma.
Volume 23, Issue 5 (11-2023)
Abstract
The construction industry produces substantial amounts of waste materials, which contribute to negative environmental impacts when disposed of in landfills. Recycling Construction and Demolition Waste (CDW) as secondary materials is an effective approach to reducing these negative effects. Recycled Concrete Aggregates (RCA) derived from distressed pavements, buildings, and concrete structures have potential for a variety of applications, including in asphalt mixes. This paper reports experimental research on the use of treated and untreated RCAs in preparing Hot Mix Asphalt (HMA). RCA materials were added in both treated and untreated form to HMA mixes. To improve the quality of recycled mixes, RCAs were treated with lime solutions. In order to improve quality of recycled mixes, RCAs were treated with lime solutions before that the recycled mixes were subjected to various tests. The treatment was applied to coarse RCA materials. The coarse RCAs were washed thoroughly, so that all noticeable impurities, including wood chips and other similar materials, were removed. These were then dried at ambient temperature for 24 h before that the treatment was applied. In order to reduce stripping susceptibility of the recycled asphalt mixtures, hydrated lime was added as a treatment additive. The addition of hydrated lime solution was beneficial due to, its abundance the convenience of application in HMA mixes. RCAs were impregnated in a 6% solution of hydrated lime for 24h at ambient temperature. Then these were dried at ambient temperature before being used in asphalt mixes. The physical and mechanical characteristics of the treated/untreated RCAs were determined. Asphalt mixtures were prepared that contained 25% and 50% RCAs of the size ranging from 4.75 to 12.5 mm. Various asphalt mixtures containing different amounts of RCAs were prepared. Moisture susceptibility of HMA mixes were evaluated using indirect tensile strength test (ITS). Fracture properties of mixes applying Semi-Circular Bending (SCB) were determined. SCB testing was performed according to ASTM D 8044 Standard testing method. Samples were prepared containing three different notches of 25, 32, and 38 mm. SCB samples were tested using a UTM machine. The loading mode as in monotonic compression at the speed of 0.5 mm/min. J-integral suggests as a criterion for resistance of materials to cracking. Testing was performed on HMA mixes treated and untreated samples. The results indicated that although treating RCAs might require more effort in production processing, significant benefits result in reducing moisture susceptibility and increasing fracture toughness of samples. It was also found that replacing virgin aggregates with RCA, improved fracture properties of HMA mixtures. The results indicated that with using RCA instead of conventional aggregates in asphalt mixes, has positive benefits for the environment and enhanced mechanical properties of HMA mixtures. A limited percentage of RCAs can be used in asphalt mixtures without significantly affecting performance of asphalt mixtures. The treatment resulted in reduced water absorption and increased fracture energy of mixes. Asphalt mixes containing 50% untreated RCA materials showed some moisture susceptibility while asphalt mixes containing 50% treated RCA showed improved moisture resistance. In conclusion, the study demonstrated that treating RCAs with hydrated lime solution improved the moisture susceptibility and fracture resistance of recycled HMA mixtures. Furthermore, utilizing recycled construction materials as secondary materials in asphalt mixes has significant environmental benefits. Future research can explore the potential use of various waste materials, including RCAs, in asphalt mixes.
Volume 26, Issue 4 (7-2024)
Abstract
Drought alters plant metabolic processes resulting in some changes at the anatomical and morphological levels. Experiments were conducted to determine the morphologic and anatomic responses of two cultivars of tomato (Solanum lycopersicum L., cultivars CaljN3 and Superstrain B) to different irrigation regimes [100, 75, 50, and 25% of Field Capacity (FC)]. Catalase 1 (CAT1) gene expression was investigated by real-time RT-qPCR and protein interaction studies in tomatoes. Drought stress caused an increase in the number of vessels in roots and stems of both cultivars. The diameter of vascular cylinders in roots of the control plants (both cultivars) was larger. Expression of the CAT1 gene did not show any significant difference in the CaljN3 cultivar under drought conditions. However, expression of the CAT1 gene indicated a significant increase in Superstrain B cultivar at the 50 and 25% FC treatments. The gene network showed that this protein interacts with superoxide dismutase, acyl-CoA oxidase, and glutathione peroxidase. CaljN3 cultivars and showed more tolerance than Superstrain B at all levels of drought treatment. Therefore, Superstrain B is considered a susceptible cultivar under drought conditions. This suggested that the defense against oxidative stress may initiate one step before the activity of antioxidant enzymes. Thus, tomato plant tries to fight the stress factor by activating proteins, especially channels, pumps, and some cellular messengers.