فهرست مطالب

  • Volume:16 Issue:3, 2018
  • تاریخ انتشار: 1397/05/02
  • تعداد عناوین: 8
  • E Asadifard, M Masoudi Pages 203-213
    In the present study, air quality analyses were conducted for carbon monoxide (CO) in Ahvaz, a city in the south of Iran. The measurements were taken from 2009 through 2010 in two different locations to prepare average data in the city. The average concentrations calculated for every 24 hours, each month and each season showed that the highest CO concentration occurs generally in the nighttime, while the least was found at in the midday. Monthly CO concentrations showed the highest values in May and June, while the least in January and February. The seasonal concentrations showed the highest amounts in the spring. Then Relations between the air pollutant and some meteorological parameters were calculated statistically using the daily average data. The wind data (velocity, direction), relative humidity, temperature, sunshine periods, dew point and rainfall were considered as independent variables. The level relationships between pollutant concentration and meteorological parameters were expressed by multiple linear and nonlinear regression equations for both annual and seasonal conditions using SPSS software. RMSE test showed that among different prediction models, stepwise model is the best option.
    Keywords: Air pollution, Carbon monoxide, Ahvaz, Meteorological Parameters, Regression model
  • L Soleimannejad, A.E. Bonyad, R. Naghdi Pages 215-230
    The Zagros forests come as one of the most valuable ecosystems in western Iran. Therefore, accurate and up-to-date information on basal area, canopy cover, and stem number per hectare of these forests are the important factors in the context of forest management and conservation. The main objective of this study was to estimate quantitative forest attributes using Landsat 8-OLI image data and Random Forest, a well-known machine learning technique. The results were shown the lowest out of bag error with the combination of 800 trees and 8 variables in each node as the optimal model parameters to classify forest canopy cover with overall accuracy and Kappa coefficient of 83% and 0.73 respectively, while those of classified mapping of basal area were 78% and 0.72, and also those of stem number per hectare were 75% and 0.69 respectively. All in all, the Random Forest classifier algorithm provided comparatively successful mapping results of quantitative attributes in Zagros open forests of Iran from Landsat 8-OLI image data.
    Keywords: Random forest classifiers, landsat 8-OLI data, Zagros forests, Iran
  • A Moradi, K Taheri Abkenar, M Afshar Mohammadian, N Shabanian Pages 231-239
    In recent years, the microdust phenomenon has greatly changed in concentration, duration and continuity as well as the frequency of occurrence in comparison with dust storms in the past which has caused a great deal of concern. Microdust is one of the most devastating factors in the environment threatening all animal and plant species. Regarding to the microdust impending threat, its ecological and economic impacts on scarce species is critical. Zagros forests act as an intrinsic filter for microdust in the western region of Iran. This study investigates the effect of microdust on oak, the most important tree in the Zagros forests. So that, three-year old seedlings of three oak species (Quercus branti, Q. libni and Q. infectoria) were exposed to microdust under natural conditions during spring and summer 2016. We examined the rate of photosynthesis, stomatal conductance, transpiration, internal CO2, mesophyll conductance, water use efficiency in control and treated plants. The results indicated that microdust had a significant impact on the examined parameters of the three oak species (P≤0.01). The gas exchange and photosynthetic rates of the treated plants were significantly reduced. In Q. infectoria, microdust had the greatest impact on photosynthesis, stomatal conductance, leaf internal CO2, transpiration and mesophyll conductance. Accordingly, microdust had a substantial influence on photosynthesis and mesophyll conductance in Q. brantii as well as the leaf internal CO2 and mesophyll conductance in Q. libani. Therefore, based on these findings, it can be concluded that microdust can disrupt the physiological activities of the examined species. Hence, continuous - exposure to microdust will accelerate the process of destruction of these forests.
    Keywords: Microdust, Forest trees, Gas exchange, Zagros
  • M Mansour Bahmany, A Vakili, M Danesh Mesgaran, M.R Rezaie Rayeni, E Rezvan Nejhad Pages 241-248
    Radon, as naturally occurring radioactive gas, is responsible for 50% of the total background radiations in human. Radon gas is able to enter to human body through eating and drinking. So, measurement of received radiation in the human body is essential. In this study, the presence of radon in milk and its dose was examined. This experiment was conducted using 12 Rayeni goats which have been categorized in a completely randomized design by 4 treatments and 3 replication (Treatment A = Radon-containing water + zero antioxidant, Treatment B = Radon-containing water + antioxidant, Treatment C = healthy water + antioxidant, Treatment D = healthy water+ zero antioxidant). The experiment was prolonged for 60 days. During the experiment the goats were milked every day. The samples were transferred to laboratory to determine the milk compounds and properties, as well as to measure its radon level. Presence of radon in milk was detected using Rad7 device. The averaged radon concentration in milk samples (for treatments A and B) receiving radon was about 126 Bq m-3. There was no significant difference between protein. But there was a significant difference between the percentages of fat, lactose, total antioxidant capacity and the number of somatic cells. Radon did not change pH and Malondialdehyde contents of the treatments. We also determined annual received radon dose per person from drinking milk. It was different among age groups. Newborns were at higher risk of internal radon exposure from contaminated milk. Radon can enter thelivestock milk. According to our findings, with, this radon amount in milk was not higher than the allowable level in valid resources for human health.
    Keywords: Radon, Milk, Antioxidant, Effective Dose
  • M Banimahd Keivani Pages 249-258
    The entrance of household wastewater to rivers has not only brought about numerous environmental problems, which have resulted in a huge problem in the society, but also led to undesirable mental and psychological effects in the society. The removal of dye from these wastewaters before entrance to rivers is of great importance. In this research, it was discovered that by depositing a layer of polyaniline-based conductive nano polymer on hazelnut skin, a nano composite was produced which helps in removing brilliant blue (BB) dye from aqueous environments. The aim of this study was to deposit a layer of polyaniline nano polymer on the surface of hazelnut skin and produce polyaniline/hazelnut skin (Pan/Hz) composite through chemical polymerization of aniline in aqueous environments and adsorption of BB dye from aqueous environments. In this stage, polyaniline was synthesized using ammonium persulfate. In order to find the optimal conditions for the removal of the dye, the effect of a number of important parameters such as pH, contact time, initial concentration of the dye, and temperature was examined. Langmuir and Freundlich isotherms were used for adsorption studies. Furthermore, thermodynamic and kinetic studies were also conducted. This dye has the greatest adsorption at pH 2 and by optimizing other mentioned parameters, the best state has been presented for maximum adsorption. Thermodynamic studies indicate that the adsorption has been spontaneous, endothermic, and chemical, following the second order kinetics. The introduced adsorbent is a very effective one for the adsorption of BB and by using a layer of conductive nano polymer on hazelnut skin, it is possible to absorb BB dye from aqueous environments with a very high percentage.
    Keywords: Pollution, Nano hazelnut skin composite, Brilliant blue, Polyaniline, Environment
  • A Makhdoumi Pages 259-269
    Bacterial diversity in the south coast of the Caspian Sea was studied by analyzing 16S rDNA clone library and cultivation technique. Analysis of inserts of 30 clones revealed a total of 13 OTUs. All of these sequences were related to Proteobacteria including Betaproteobacteria (60%), Gammaproteobacteria (22%) and Alphaproteobacteria (18%). The majority of these sequences (40%) branched with member of Limnobacter. Within the cultivation effort, phylotypes related to Gammaproteobacteria (60%), Firmicutes (27%), Actinobacteria (9%) and Bacteroidetes (4%) were retrieved. Members of the Bacillus (14%) and Rheinheimera (18%) were the most common isolates. The secretions of eight hydrolytic enzymes and antibiotic compounds, as well as resistance to heavy metals were studied in these marine strains. Among them 46, 45, 38, 27, 19, 19, 7 and 4% of bacterial isolates were able to produce protease, pectinase, xylanase, amylase, cellulase, lipase, urease and DNase, respectively. Two strains which are phylogenetically related to Streptomyces and Stenotrophomonas produced antimicrobial compounds and could inhibit the growth of Candida albicans and Bacillus subtilis,respectively. A total of 2, 1, 2, 3 and 2 strains could survive in the presence of lead (1500 ppm), cadmium (1000 ppm), zinc (2000 ppm), copper (2000 ppm), and Chromium (2000 ppm), respectively. The investigation showed that this marine environment harbors a high bacterial diversity which is a potential source of hydrolytic enzymes and other valuable biotechnological activities.
    Keywords: Antimicrobial compounds, Bacterial diversity, Caspian Sea, Heavy metal resistance, Hydrolytic enzymes
  • P Alemi Safaval, M Kheirkhah Zarkesh, S.A Neshaei, F Ejlali Pages 271-285
    Coastal areas are continuously under the regional changing and interaction of land-sea resulting in the short and long terms deformation. Study of beach morphology has been one of the most important issues in coastal engineering research projects. Managing and controlling the shoreline changes and behavior are essential for all marine projects and integrated coastal zone management policy in such environments. In the present study, Guilan Province region was selected and an analysis of the coastal zone behavior was carried out based on the available satellite images. According to results, we estimated the bed level changes and also submerged area, resulting from a rise in sea level at different locations in the study area (from Anzali Port to Boujagh National Park) and compared them with those obtained from the satellite images. The results were presented graphically and changes in shorelines were estimated using ETM+ sensors and OLI images from 2002 to 2013 which can be used for site selection and design of marine structures and establishing a data base for the coastal zone in the study region. Laplacian filter was applied to satellite images to establish the shoreline and to clarify the effect of ports and coastal structures constructed in the study region on beach and shoreline morphological changes. This study is a combination of remote sensing and GIS systems with field surveys on the ground. The innovation of this work is the application of Laplacian filter for shoreline detection and estimation of the sediment deposition area by calculating the distance between the observed shorelines. This will lead to the better understanding of the effect of coastal structures on the beach morphology using satellite images. The results show the remarkable changes occurred in the shoreline due to the environmental and human-based effects during the eleven years period. The present study can be considered as a contribution to the existing knowledge of the coastal process in the study area and referred to as a basis for the future coastal research projects.
    Keywords: Caspian Sea, change detection, coastline, GIS, laplacian filter, remote sensing
  • Z Bozorgpanah Kharat, M Mohammadi Galangash, A Ghavidast, M Shirzad, Siboni Pages 287-301
    In this study, Fe3O4@SiO2-APTES nanoparticles were successfully synthesized via a one-pot route in order to remove reactive black 5 dye from aqueous solutions. To obtain optimal conditions on the dye removal efficiency, the effects of various parameters were investigated including solution pH, initial dye concentration, and absorbent dosage. According to the experimental results, the removal efficiency of the dye decreased with increasing in pH and initial dye concentration, as well as with decreased adsorbent dosage. In fact, about 100.00 % of reactive black 5 was removed from aqueous solution using Fe3O4@SiO2-APTES NPs at the adsorbent amount of 0.4 g L-1 and pH = 3 in 90 min. The kinetics were found well match with pseudo-second-order equation. The isotherm analysis indicated that the equilibrium data were well fitted to the Langmuir isotherm model, showing a monolayer adsorption manner of the dyes on homogeneous surface of nanoparticles. Also, the results of absorbent recycling showed that this nanoparticle could be reused up to 6 times with high efficiency.
    Keywords: Fe3O4@SiO2-APTES nanoparticles, Reactive Black 5, Kinetic, Isotherm