Showing 9 results for khosravi
E Kalantar, A Maleki, M Khosravi, S Mahmodi,
Volume 3, Issue 3 (4 2010)
Abstract
BackgroundsAandObjectives: Pseudomonas aeruginosa and Staphylococcus aureus are important pathogens that producewidespread infections. Purpose of this studywas to evaluate the antimicrobial effect of ultrasonic irradiation (US) alone and in combination with antibiotic on antibiotic resistance Pseudomonas aeruginosa and Staphylococcus aureus.
Materials and Methods: In this study ultrasonic irradiation (US) in a laboratory-scale batch sonoreactor with low frequency (42 kHz) plate type transducer at 170W of acoustic power was used. The Water samples, were taken from different wards of the 3 teaching hospitals which were affiliated to the Kurdistan University of Medical Sciences to isolate Pseudomonas aeruginosa and Staphylococcus aureus and also to determine their antimicrobial susceptibility pattern.
Results:Our results showed that Pseudomonas aeruginosa and Staphylococcus aureus were affected by the ultrasound and the bactericidal effect increased with time.
Conclusion: It was found that P. aeruginosa was more susceptible to the ultrasonic treatment than S. aureus. The combination of US with an antibiotic (amoxicillin) enhanced killing of both bacteria over the use of US alone. There were no differences in resistance to ultrasound between isolated strains and standard strains from persian type culture collection.
M Khosravi, N Bahramifar, M Ghasempour,
Volume 4, Issue 2 (9 2011)
Abstract
Background and Objectives:Anzali Wetland is one of the most important aquatic ecosystems of Iran which is located in south-west of the Caspian sea. This Wetland provides a suitable and non-market price habitat for valuable fish and aquatic animals which have an important role in the life cycle of this ecosystem. This study reports the results of some heavy metals contamination monitoring in superficial water of the Anzali Wetland, Iran.
Materials and Methods: The samples were collected from three sites (east, center and west) of Anzali Wetland, in each site three stations existed and each sample replicated three times.
Results: The results showed high heavy metal levels in eastern site of wetland, where there were high levels of contamination. The mean of heavy metals concentration in sediment from Anzali Wetland were in order as Cd 157.023, Pb 3.646 and Hg 300.692 ng /g dried weight, Zn 186.953 and Cu 44.452 mg /g dried weight in eastern site. The concentration levels of heavy metals in three sites were in order as follows: Zn > Cu > Hg > Cd > Pb.
Conclusion: Concentrations of heavy metals in eastern zone reflected metal loadings from anthropogenic sources located at and in the vicinity of the sampling sites.
R Khosravi, G.r Moussavi, Sh. Roudbar Mohammadi,
Volume 4, Issue 4 (2 2012)
Abstract
Background and Objectives: Effluent generated in several industries contains phenolic compounds, which have been classified as priority pollutants. Due to its toxicity, the conventional systems are inefficient for treatment of phenol-Laden wastewater. Biological processes using pure microbial culture, including fungi and yeast, are environmentally friendly techniques capable of complete destruction of contaminants.
Materials and Methods: This work was aimed at investigating the efficiency of a fungi specie in the decomposition of high concentrations of phenol ranging from 500 to 20000 mg/L. Several batch reactors were operated at different phenol concentration. The concentration of residual phenol was monitored over time using colorimetric method 4-aminoantipyrine. The removal efficiency was calculated considering the initial phenol concentration.
Results: Experimental data indicated that the phenol could efficiently degrade using the selected culture. The developed granules could completely degrade phenol at concentrations up to 20000 mg/L.
Conclusion: It can be concluded from the experimental data that the biodegradation using the Fungi granules is a very efficient and thus promising technique for treatment of wastewaters containing phenolic compounds.
Mostafa Leili, Gholamreza Moussavi, Kazem Nadafi, Rasoul Khosravi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and Objectives: Furfural with a chemical formula of C5H4O2 is a toxic and hazardous substance for human and environment. Furfural and its derivatives such as furfuryl alcohol, alone or in combination with phenol, acetone or urea are used mainly in the production of resin. The second major application of furfural is in the production of solvents such furan and tetrafuran frequently used as a selective solvent in the production, treatment, and refining lubricants from petroleum products. A few studies have recently been done in terms of removal or recovery of furfural. Due to advantages of biological methods, the uses of theses environmentally friendly methods are being investigated in this study.
Materials and Methods: We used cyclic biological reactor (CBR) and Fusarium culmorum granules to biologically degrade different concentration of furfural and equivalent of COD under different operating conditions. The analysis was based on the measurement of furfural degradation efficiency during operational period using spectrophotometer and measuring influent and effluent COD variations using a closed reflux method.
Results: cyclic biological reactor was operated in various flow rate (Q) of furfural-containing wastewater for a different period. For all of the flow rate used, furfural degradation and COD removal efficiency was over 99 and 90 percent respectively. Fusarium culmorum granules were also exposed to different concentrations of furfural at different incubation temperatures showing high furfural removal capacity. Conclusion: Under different operating conditions of biological systems, high removal efficiency of furfural was observed, but CBR in comparison with Fusarium culmorum granules reached the optimum and desired removal efficiency in shorter time. Therefore, these systems can be developed and replaced with chemical methods to treat furfural containing wastewater.
F Majidi, Y Khosravi,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objective: The aim of noise control in a community is to improve its management in the community, because the traffic noise can affect neighboring residential areas. Well-planned noise management can eliminate this major and harmful component issue, which is one of the stresses of urban life on human health. However, before planning to decrease urban noise, it is necessary to determine the very noisy areas in a given city. Therefore, the objective of this study was to measure the main noise indices at the noisy areas of Zanjan City, Iran.
Materials and Methods: This study was performed in the central area of Zanjan City, with heavy traffic. For this purpose, the equivalent sound level (Leq), the day-night sound level (Ldn), the day-evening-night sound level (Lden), the noise pollution level (NP) and the traffic noise index (TNI) were measured in 19 stations in the first half (winter and spring) of 2012. The measurements were conducted in the main streets of this area as recommended by EPA guidelines and finally the results obtained were mapped using the ArcGIS (Ver. 10.2) software.
Results: the noise maps in GIS showed clearly the variations of Leq, Ldn, and Lden indices in the study field area. Moreover, it was found that the hourly variations of Leq, Ldn and Lden in stations are completely function of population movements and therefore traffic loads in the Zanjan city center. In addition, the extent of violation of traffic noise level from the ambient noise standard was estimated by Lden at 100% stations (greater than 55 dB). The TNI values at 67 and 100% stations were more than 74 dB (A), but in the evenings the TNI values at 100% of stations were more than 74 dB (A). The NP values at 78% sampling stations were more than 80 dB implying traffic noise was annoying in the most stations and times.
Conclusion: Using noise maps, NP and TNI indices can help intelligent traffic control planning, because the noise maps can be used to represent the movement of people in different times and parts of a city.
A Tavakoli, A Parizanganeh, Y Khosravi, P Hemmati,
Volume 10, Issue 1 (6-2017)
Abstract
Background and Objective: Radon is highly regarded because of its impacts on public health. Northern regions of Iran have a high potential for radon emissions. This research aimed to measure residential radon concentrations in Tarom country- Zanjan and to compare the results with international standards and acceptable values.
Materials and Methods: Passive diffusive samplers, Solid State Nuclear Track Detector (SSNTD), with the ability to determine background and longtime concentration, were selected for this study. A total of 30 detectors were located based on a pre-identified network in the residential buildings of Chavarzaq, Ab Bar and Gilvan for a period of three months. Then, detectors were sent to a laboratory for counting the traces.
Results: Based on the results, average radon concentrations in Chavarzaq, Ab Bar and Gilvan were 220.51, 95.25 and 119.84 Bq/m3, respectively. The average radon concentration in Tarom was about 130.57 Bq/m3. There was no meaningful relationship between radon concentration with the age of buildings or number of occupants. In comparison of the results with USEPA standards it was observed that among total samples just one of them was in the range of target level, and 15 detectors were in the range of target to action levels and the remaining samples showed high level of radon requiring corrective measures. In addition, 12 detectors showed values less than the reference level of WHO and the remaining detectors had higher values than WHO level.
Conclusion: Based on results of this research, soil analysis before construction, application of building materials resistant to leakage and regular monitoring of radon levels in region were suggested.
M Abadi, Aa Zamani, A Parizanganeh, Y Khosravi, H Badiee,
Volume 10, Issue 3 (12-2017)
Abstract
Background and Objective: Mercury (Hg) contamination in marine ecosystems is a major threat to human health in the developing countries like Iran. The main route of mercury exposure is from consumption of fish and seafood. Upon entering mercury in human bodies, Hg is converted into methyl mercury, which may lead to serious implications including neurological disorders, reproductive abnormalities, kidney failure, emotional instability, gingivitis and tremors. Therefore, research on mercury concentrations in marine ecosystems (water and fishes) can be help to protect human health and reduce the risks of mercury contamination.
Materials and Methods: In this study in order to evaluate the concentrations of Hg in water and fish, water samples (36 stations), fish tissue livers (n=33) and muscles (n=33) of four fish species from the Caspian Sea (southern coasts) were collected and analyzed. For determination of Hg in water and fish samples, Voltammetry and GF-AAS techniques were used, respectively.
Results: The results showed that the average Hg concentration detected in water samples was 1.657 (μg/L) and in fish muscle and liver tissues were 68.636 and 125.606 (μg/g.dw), respectively. The bioaccumulation factor showed that mercury concentrations from water to fish are in the range of 14 to 80 times. The highest levels of mercury in water and fish were observed in the southwest coasts of the Caspian Sea.
Conclusion: According to USEPA and SPPA (China) standards, more than 58 % of the water samples collected from the southern coasts of the Sea was polluted by mercury. However, the average concentrations of mercury in fish samples were less than the standards by WHO and EPA.
Fatemeh Mohebbian, Azadeh Tavakoli, Abdolhossein Parizanganeh, Younes Khosravi, Isa Eskandari,
Volume 13, Issue 1 (4-2020)
Abstract
Background and Objective: Conversion of houses into residential towers in worn-out urban textures increases population. Schools of the vicinity would face with multiplicity and limited space for students, leading to noise pollution. The purpose of this study was to evaluate the noise levels during morning and afternoon shifts among two primary schools in Zanjan.
Materials and Methods: Measurements had been done using sound level meter, KIMO DB100. The equivalent noise level (Leq) measured during school year (2018-2019) in 10 stations. The measurements were done in three seasons (autumn, winter and spring) and in each season for two weeks. The data of the two schools were used for drawing charts and zoning by ArcGIS using IDW method. In addition, questionnaires were distributed among the teachers and school’ neighbors. The data were analyzed by SPSS software.
Results: The results showed that all the stations were tackled with noise pollution. The highest levels were related to school’s shift change and break times. The morning shift schools experienced higher levels of noise in comparison to the afternoon ones (1.87 and 2.1 dB, respectively for boys and girls). Leq values for boys’ school was 2 dB higher than that of the girls’. The noise level in the schools were 72 dB, which is 17 dB higher than the standard level 55 dB.
Conclusion: The residents living close to the schools were exposed to noise pollution for almost 10 hours a day. This could be regarded as harmful. The zoning maps showed that southwest side of the yard, adjacent to the neighboring residential buildings, had the highest levels of noise. This study demonstrated the site selection for the schools were not properly done. Having a control strategy is needed.
Parvane Dowlati, Hatam Godini, Abbas Moghimbeigi, Yahya Khosravi,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: In this research, considering the importance of the adverse effects of the Covid-19 disease and identifying the environmental factors involved in its outbreak, the effects of environmental factors and compliance with health guidelines on outbreak and mortality of Covid-19 have been evaluated.
Materials and Methods: This research was a descriptive-analytical study on confirmed patients with Covid-19 in Alborz province in 2019. In this study, outbreak rate and death due to Covid-19, compliance with health guidelines, air pollutants concentrations, air pollution indicators, and the meteorological conditions of Alborz province were daily collected for 2019. All data were analyzed in IBM SPSS Statistics v26 software with Pearson, Spearman, Kruskal-Wallis, one-way variance ANOVA analysis tests, and negative binomial regression statistical models.
Results: The results of the regression model showed that in the mortality rate due to Covid-19, the variables of average temperature(p=0.042), humidity(p=0.048), rate of Covid-19 infection(p=0.001), and compliance with health guidelines(p=0.007) are significant. However, in the model of the rate of infection with Covid-19, only compliance with health guidelines(p=0.001) was significant. Pearson's and Spearman's correlation coefficients for infection rate, compliance with health guidelines, wind speed, and concentrations of carbon monoxide, PM2.5, and SO2 with the death rate due to corona, were 0.575, -0.411, -0.206, 0.211, 0.114 and -0.158.
Conclusion: The results showed that in addition to compliance with health guidelines, some atmospheric factors and air pollutants also impact the rate of infection and mortality caused by Covid-19.
