Showing 9 results for Motalebi
Volume 5, Issue 1 (Winter 2019)
Abstract
Background: Biodegradation is the metabolic ability of some microorganisms in degrading or transforming the organic and inorganic contaminants into less harmful and non-hazardous substances, which are then integrated into the natural biogeochemical cycles. Some microorganisms, mainly the members of family Actinomycetes, were found with the capability of transforming and degrading the polluting agents. In this study, three different Nocardia species with the ability to biodegrade organic and inorganic compounds were isolated from soil in Isfahan province.
Materials & Methods: The soil samples were collected from the hospital environments. Isolation process was done according to the standard methods. The identification and characterization of the isolates were based on the conventional and molecular methods, including direct sequence analysis of almost full length of 16S rRNA gene.
Results: Almost, the complete 16S rRNA gene sequences of the strains under study revealed that the isolates coded as NR6, NR17, NR18, NR25, NR26, and NR28 were the strains of N. cyriacigeorgica; NR7, NR34, and NR50 were the strains of N. coubleae; and NR4 was the strain of N. otitidiscaviarum. The relationship between the isolates under study and standard strain of Nocardia was supported by a phylogenetic tree of 16S rRNA gene.
Conclusion: In this study, 10 Nocardia strains with the capability of biotransforming polluting agents were isolated from the hospital environments. It was the first study conducted on the isolation and characterization of Nocardia strains, with the capability of degrading polluting agents, from Iranian hospitals. This study can be considered as a pioneer to develop a new insight about the study of microbial diversity in Iran using an applied approach to deal with environmental challenges.
Volume 10, Issue 1 (Spring 2020)
Abstract
Aims: The purpose of this study is to measure the level of social sustainability in distressed urban areas and explain its components in the historical and marginal context of Ardabil as two examples of distressed urban areas.
Methods: The data were collected by library method and questionnaire in 2018 and analyzed by one-sample t-test, factor analysis and regression analysis. The sample consisted of 200 inhabitants of historical texture and 200 inhabitants of marginal context who were sampled by cluster sampling method.
Findings: The components of social sustainability in both studied areas were inadequate. However, the marginal context was worse than historical area. Based on the results of factor analysis, factors that contribute to the improvement of social sustainability are in the subset of the four main factors, which together explain 63% to 68% of variance of the social sustainability as dependent variable. Also the effect of various factors in each area was significantly different. As, the most important factor affecting social sustainability in the historical context is the social capital that explained by variables such as social participation, social interactions, social trust, and collective identity. In contrast, the most important factor affecting social sustainability in marginalized area is the availability of amenities and infrastructural facilities that are explained by variables such as housing quality, security and access to public services.
Conclusion: The final result was that the existence of intrinsic differences between historical and marginal context requires the development of separate regeneration schemes for each context in accordance with their characteristics.
Volume 12, Issue 3 (summer 2021)
Abstract
Aims The secondary metabolites of plants have been considered due to their diversity and roles in plants and human health. Grapevine is one of the plants that have secondary compounds with medicinal properties. such compounds include resveratrol which is a phenolic compound from the stilbenoid group. In order to investigate the resveratrol production under the effect of an elicitor, a CRD design with four replications using Soltani cultivar was done.
Materials & Methods. The salicylic acid (SA) was used as an elicitor with variable concentrations including 0, 10-4, 10-5, 10-6 and was introduced into MS medium without hormones to examine it`s stress effects. At the molecular level, the effect of SA on the expression of stilbene-synthase gene was evaluated by semi-quantitative RT-PCR. In the biochemical experiment, the rate of resveratrol production was measured by HPLC.
Findings Stilbene-synthase expression analysis showed that SA with a concentration of 10-4 M had a positive and incremental effect on gene expression and showed a 35.48% of increase compared to the control state, and also the concentration of 10-5 M increased the gene expression 5.65% in relation with control state. In the biochemical experiment, increasing in production of resveratrol was observed in 10-4 M treatment compared to the control treatment (6.1 µg) and 10-5 M treatment (3.25 µg) did not show a significant difference with the control sample.
Conclusion SA as an elicitor and stimulant of resveratrol production could enhance the expression of stilbene-synthase gene followed by enhancing the medicinal properties of the Vitis plant.
Volume 13, Issue 52 (4-2016)
Abstract
In this study the effect of different slaughter methods were examined on the quality of rainbow trout during 12 days storage in refrigerator. Treatments were included choked (suffocated) the fish out of water (control), blows to the head with a mallet, cut the base of gill and abdominal drain and the use of water and ice and then hit in the head with a mallet. Peroxide value in abovementioned treatments were increased from 0.96 to 11.03, from 0.92 to 10.60, from 0.86 to 10.20 and from 0.88 to 10.40 meq/kg during storage at 4 ºC, respectively. There were significant differences (P<0.05) in peroxide value (PV), thiobarbituric acid (TBA) and free fatty acid (FFA) content between different slaughter treatments during storage in refrigerator. Slaughter treatments had significant effect on bacterial loading. Lower mesophilic and TVC count during storage period was observed in use of water and ice and then hit in the head treatment followed by cut the base of gill and abdominal drain treatment. All treated samples reached to 7 logCFU/g at day 9. The result showed that gill based amputation treatment had best impact on the quality of rainbow trout during storage period.
Volume 16, Issue 4 (7-2014)
Abstract
In this study, a numerical model was developed to investigate the two-dimensional heat transfer in a homogenous finite cylinder to predict the local temperature and sterilizing value during caviar pasteurization. A fixed grid finite difference method was used in the solution of heat transfer equations according to Crank-Nicolson’s scheme. The model was validated by comparison of the experimental temperature profiles during caviar pasteurization with the model predicted values (Correlation Coefficient> 0.99 and Root Mean Square Errors< 0.61ºC). The cold spot location was at the radial center between the middle and top of the jar on the vertical axis. For caviar pasteurization, the required heating time for cold spot to reach the desired F-value (= 0.19 min) was 128 minutes at 55°C and 37.63 minutes at 65°C. The results indicated that the developed model could be successfully applied to simulate the caviar thermal processing.
Volume 16, Issue 88 (6-2019)
Abstract
In this study, gelatin from common carp scales (Cyprinus carpio) was produced using alkaline, acidic and thermal methods. Then, the physical factors, barrier properties and its appearance characteristics were optimized by changing effective factors in the initial gelatin extraction process. In order to optimize the film, the response surface methodology included a central composite design for extraction process, a series of effective factors in extraction including sodium hydroxide concentration, alkaline pre-treatment, hydrochloric acid concentration and extraction temperature as independent variables were investigated. The dependent variables including tensile properties, water solubility and water vapor permeability were investigated. The results of screening based on mechanical strength and solubility resulted in the selection of 4 factors of 9 factors. In the screening stage, four variables including two factor of the pH of extraction and the duration of the alkaline treatment that had the greatest effect on the tensile strength, and two factor including concentrations of acid treatments and the extraction temperature that had the most effect on the solubility of the films were selected for the the main experiments with gelatin extraction. Other variables that did not have a significant impact on the mechanical properties and film solubility were in their most common form. The main experiments of gelatin extraction included 30 treatments. Solubility showed significant changes (p <0.05). The lowest solubility was 25.08% for treatment No. 9 with alkaline treatment for 195 minutes, acid treatment with 0.3 molar concentration and extraction at 63 ° C. The lowest permeability was for treatment No. 15 with alkaline treatment for 140 minutes, acidic treatment with a concentration of 0.18 molar and extraction at 76 ° C (p <0.05). Finally, it was determined that by changing some of the extraction factors, the properties of gelatin film obtained from common carp scales could be optimized.
Volume 17, Issue 3 (9-2017)
Abstract
Reflective beaches requires a combination of lower waves, longer periods and particularly coarser sands. They are typically steep in beach profile with a narrow shoaling and surf zone, composed of coarse sediment. Coarser sediment allows percolation during the swash part of the wave cycle, thus reducing the strength of backwash and allowing material be deposited in the swash zone
The Swash zone, as extreme area of inner surf zone, influences coastal area and coastal structures. It defined as the part of the beach between the minimum wave run-down and maximum wave run-up. It constitutes a beach area where waves dissipate or reflect their remaining energy after traveling towards the shore. The role of Swash zone is influenced by incoming waves from surf zone, the geometry of beach face and the interaction between beach groundwater and surf zone.
The review of Laboratory researches indicated that wave height and period, beach slope, grain size distribution of beach material, still water level (SWL), beach groundwater level, the hydraulic conductivity of beach influence on the evolution of sand beaches. In a few laboratory researches, experiments is designed with One Factor At a Time method (OFAT) and the qualitative effect of parameters of regular wave height and period, SWL and beach groundwater level, and beach slope are investigated on nearshore evolution.
In this research, experiments are designed using Central Composite Design (CCD) of Response Surface Method (RSM). CCD is a type of response surface design that present very good predictions in the middle of the design space. Important properties and features of CCD are orthogonality, rotatability and uniformity. The quantitative effects and interactions of irregular wave height and period, beach groundwater level and SWL, and beach slope on beach profile evolution is examined in a sandy beach by 50 experiments designed with CCD. The experiments are carried out in laboratory flume in Faculty of Civil and Environmental Engineering, Tarbiat Modares University with high accuracy. The experimental setup is designed to simulate varying beach groundwater level and SWL and course sand (d50=0.8mm) is selected for beach material. Analysis of hydrodynamic data of the experiments indicated that the type of breaking waves is plunging wave and the hydrodynamic status of the swash zone is intermediate condition. The starting position of swash sedimentation (SWS) is extracted from mean of the beach profiles evolution.
By analyzing of experiments' SWS using CCD, a cubic model is suggested with %95 confidence level and predicted R-squared of 0.86. The results of model revealed that groundwater level has no significant effect on SWS. Wave height is the most influential factor affecting SWS and increasing wave height result to this position moves to upper beach rapidly. In addition, increasing beach slope causes the movement of SWS toward the beach. Increasing sea level lead to the displacement of SWS toward the sea.
This model indicated that the effect of wave height on SWS depends on wave period strongly and there is significant interaction between them. In addition, there is slightly interaction between the SWL and wave height and these variables influence on the role of each other in SWS.
Volume 21, Issue 2 (summer 2021 2021)
Abstract
Globalization is a driving force in emitting carbon dioxide (CO2), which causes countries to interact with each other economically, socially and politically. The interaction between countries will inevitably affect CO2 emissions. The aim of this study is to investigate the dynamic effects of globalization and energy consumption on environmental degradation in Iran. Therefore, it examines which variable (globalization, energy consumption or economic growth) is more effective in the process of environmental degradation. The Fully Modified Least Squares (FMOLS) and Charnes, Cooper and Rhodes (CCR) models are applied to investigate the subject over the period 1978-2016. In addition, Maki co-integration test is used to check the long-term dynamic relationships. The results show that globalization increases environmental degradation regardless of the decrease or increase in economic growth. This indicates that the scale effect of is dominant in Iran.
Volume 21, Issue 4 (Winter 2017)
Abstract
Climate change refers to the changes in the mean or variations of the climatic characteristics wich will exist for a long period of time. These changes are both of natural and man-made causes. In this study, we used the data on minimum temperature and the atmospheric general circulation models in order to simulate the minimum temperature variations. We also used correlation coefficients and root mean square methods to evaluate the performance of these models. In this study, the years between 1961-1990 were used as the base period to study the changes in the minimum temperature in the future decadal periods of 2011-2040, 2041-2070, and 2071-2099. The results showed that in the coming decades the minimum temperatures tend to decrease. The estimated simulated minimum temperatures using SDSM and artificial neural network model differ some 1.8 and 2.3 C˚ in January compared to the data observed. According to estimates of the two models in the years 2011-2040 in January temperature of 3.3 C˚ temperature rise for years by 2041 to 2070 an estimated 4.7 and for the period 2071 to 2099 will increase by about 5.05 C˚. This study showed that the results of the SDSM model were closer to real values than those of the neural networks models.
