Showing 6 results for Standard
N Jaafarzadeh Haghighi Fard, S Salamat, Z Rezvani, M.a Behrooz,
Volume 2, Issue 3 (11-2009)
Abstract
Backgrounds and Objectives: As industries are developed, human uses of the energy in the huge scale and release the loss energy in the form of electromagnetic radiation such as infrared into the environment, that it could affect on the man health. According to the available standards, if the IR-A could be controlled and consequently health of workers could be provided, it would reduce the total industrial expenses.
Materials and Methods: To control this radiation, it is necessary to measure it and compare the results with the available standards. Hence, in this study, we try to measure this radiation in a unit of industy. For this porpuse the unit of steel company that settled in southeast of ahvaz is selected.
Results: The determinations were done every month during one year in all selected units. These results are compared with the available standards, and finally the differences are statistically evaluated by some suitable statistical methods. For measuring the dispersal of ray in the diffrent height. bat hard data compared with ACGIH standard and SPSS software is used for changing Radiation.
Conclusion: The average amount of IR-A at this industrial unit is 1.18 mW/cm2 which is more than the standard value in such industries ,and based on our fouding the natural solar source of this radiation increases such effects in out-door work places.
M Ghanbari, K Nadafi, M Mosaferi, M Yunesian, H Aslani,
Volume 4, Issue 3 (10-2011)
Abstract
Background and Objectives: Over the last three decades environmental pollutions became a more noticeable problem in all around of the world. In many countries, noise pollution as a basic problem has a great importance.Development of the city, increasing of industrial centers, increasing vehicles, other annoying noise resources and also little information about the noise pollution of Tabriz city, has led to the doing of this research.
Materials and Methods: Sampling and measuring of noise pressure levels was done 180 times According to the EPA standards, measuring was done simultaneously in two stations(commercial-residential areas), three times a day (morning 7:30 -9:30 am, midday 12:30-14:30 pm and night 19:00-21:00 pm) and 30 days in month.
Results: Sound pressure level in both stations was higher than the standards and the highest average level with 71.4 db was recorded in Raste-koche station at midday. Also lowest calculated average value with 68.5 db was measured in Golbad station at the morning time that is 8.5 db higher than the standards.
Conclusion: Average measured sound pressure level in two stations was higher than the standards. The results show that Tabriz has a noise pollution in commercial and residential - commercial areas. It is suggested that other noise pollution resources identified and the proper management actions for its reduction be done.
P. Nassiri, M.r Monazzam, K Azam, N Hosseini Gousheh, S Farhang Dehghan,
Volume 4, Issue 4 (3-2012)
Abstract
Background and Objectives: Sound of motorcycles plays an important role in noise pollution in big cities. This is due to the lack of national law or standards to control the noise of domestic and also imported motorcycles. This study tries to introduce a practical limit value in different stage of motorcycle life cycle by assessing their noise pollution.
Materials and Methods: First the motorcycles noise standards at different countries were studied and they were compared with the results from noise level of 622 motorcycles in 3 different groups. The sample volume in each group corresponds to the amount of their annual production rate. Then using statistical tests, a limit was determined in which 90% of the domestic motorcycles can be covered. The limit is proposed as the standard for domestic motorcycle noise.
Results: The limit for motorcycles of groups 1, 2 and 3were 84, 86 and 87 dB (A) ,respectively in the TA stage. For the COP stage (Conformity of Production), the limit increases according to certain formula. In the end, a flowchart was proposed as a standard method for measuring the sound of motorcycles in the TA and COP stages was proposed.
Conclusion: Noise level of the domestic motorcycles is at least 9 dB (A) higher than the noise limit value of European motorcycle. If European limit value is considered for producing the national motorcycle, 90% of them will get out of production cycle and this would not be practical.
Akbar Eslami, Hamzehali Jamali, Shirin Naderi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and Objectives: Water is essential for sustaining life & adequate safe supplies must be accessible to the public. Nowadays, people prefer to purchase bottled water for reasons including taste, convenience, following fashion, and its safety and sanitary conditions. According to the WHO guideline, it is of great importance to control the bottled water because of keeping it for longer period of time and at higher temperature in comparison with the water of distribution networks, reusing containers and bottles without adequate washing and disinfecting, and more growth of microorganisms having less important in the terms of health. The aim of this study was to investigate the microbial and physicochemical quality of bottled water in the stores of Qazvin City and to compare the aforesaid features with national standards and to check the quality with the bottles label.
Materials and Methods: In this cross-sectional study, 51 samples of 11 bottled water brands with different production date were obtained. The features were studied in accordance with Standard Methods. Then, the data were analyzed by T-Test and one way ANOVA analysis using SPSS software. Eventually, the results were compared with the national standards, the WHO guidelines, and the product labels.
Results: Results showed lack of microbial contamination of the samples. Physically and chemically, all the parameters measured were below the national standards level. Study of conformity of the variables to the label indicated that mostly there was a significant difference between the values measured and the values listed on the product labels.
Conclusion: Although the concentration of microbial, physical and chemical features of samples were in the extent of national standards, there was a meaningful difference between labels and measured values so that the average concentration of TDS, TH, SO4-2, Ca2+, Mg2+ and Na+ would be more than the label values and the average of the other parameters was lower than the label values.
R Dehghan, S Abdolahi, M Rahimi, F Nejad Koorki, M Amini,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Due to the increasing growth of urbanization, vehicles are one of the most important environmental causes of air pollution in today's world.. With the increasing problems of air pollution and its environmental consequences due to lack of compliance with standards in manufacturing cars and their fuel consumption, awareness of the exhaust of cars and its comparison with environmental protection standards and technical examination is essential for controlling and reducing air pollution. Therefore, the present study was carried out with the aim of studying and comparing the amount of CO, CO2 and HC emissions from light vehicle exhausts in the period of 1383-1389 based on technical and environmental inspection standards in Shiraz. Also, the relationship between the year of construction of the car and the amount of output of these pollutants was discussed.
Materials and Methods: In this research, the amount of exhaust emissions (carbon monoxide, carbon dioxide and uncured hydrocarbons) from the exhaust of 858 vehicles included models Peugeot 206, GLX and Pars that were referred to the technical examination center during 5 months in Shiraz between the years 1383-1389 was investigated. Also, the relationship between the year of production and the amount of output of these pollutants was studied. Data analysis was done using SPSS software and Microsoft Excel software was used for drawing graphs.
Results: The results showed that there was a significant and negative correlation between the year of manufacture of the vehicle and the reduction of CO and HC. As the year of construction increases, the amount of pollutants is decreasing. Also, this relationship was positive and significant between the year of manufacture and CO2. Also, the exhaust pollutants (CO and CO2) from the Peugeot GLX exhaust system were lower than Peugeot Pars and 206, and the lowest amount of HC was observed in Peugeot 206.
Conclusion: In general, the exhaust emissions of all three cars were at the standard Euro 2 and technical examination.
Gholamreza Shaghaghi, Amir Hossein Javid, Sara Allahyaribeik, Ali Mashinchian Moradi,
Volume 17, Issue 3 (12-2024)
Abstract
Background and Objective: The discharge of seawater concentrate from desalination plants into the sea causes irreparable effects on the environment. The purpose of this study is to identify the effects of this discharge, model methods for optimizing it, and design an effective outlet that minimizes environmental impacts and costs.
Materials and Methods: This study discusses impacts of seawater concentrate discharged into the sea, numerical modeling of diffusion, and outlet design based on discharge standards.A review of articles and sources from databases such as Google Scholar, Academia, Scopus, Civilica and Irandak was conducted using keywords such as “brine discharge”, “numerical modeling”, and “outlet design.” Out of 132 reviewed articles, 45 articles were consistent with the objectives of the study.
Results: The effects of seawater discharge can be observed in the discharge area and at greater distances. Numerical modeling is employed to predict pollutant concentrations at various distances and to determine the optimal discharge point while considering established standards. The design of the diffuser and the use of multiple nozzles at an angle of 60 degrees result in the greatest dilution at the discharge point.
Conclusion: The use of desalination systems necessitates addressing the effects of climate change. Appropriate modeling and design of the outlet are essential for complying with environmental standards and optimizing costs. Further research in this field is needed.
