خيارات البحث
النتائج 261 - 270 من 616
N-acetyl-β-d-glucosaminidase measurement on the freshwater amphipod Gammarus fossarum: development, biological variability and application in an ecotoxicological approach النص الكامل
2023
Rollin, Marc | Coulaud, Romain | Quéau, Hervé | Delorme, Nicolas | Duflot, Aurélie | Le Foll, Frank | Geffard, Olivier | Xuereb, Benoit | Stress Environnementaux et BIOsurveillance des milieux aquatiques (SEBIO) ; Institut National de l'Environnement Industriel et des Risques (INERIS)-Université de Reims Champagne-Ardenne (URCA)-Université Le Havre Normandie (ULH) ; Normandie Université (NU)-Normandie Université (NU)-SFR Condorcet ; Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS) | RiverLy - Fonctionnement des hydrosystèmes (RiverLy) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
International audience | Due to its role in the crustacean moulting process, N-acetyl-beta-d-glucosaminidase (NAGase) is interesting to monitor the good proceeding of the moult cycle, as well as relevant in assessing changes in the moulting process caused by stressors. The present study aimed to measure the NAGase activity to monitor the moulting process of the freshwater amphipod Gammarus fossarum. Firstly, an optimised protocol measuring the NAGase activity was made, allowing a robustness and reproducibility of measurements. Then, intrinsic variability of NAGase response was checked under two physiological factors: the gammarid moult cycle and gender. For both genders, a significative increase of activity was observed during premoult, instead of a basal activity detected during postmoult and intermoult. However, the NAGase female profile was preconised to study since it was defined with more precision. Finally, a 16-day exposure of female gammarids to different levels of treated or non-treated wastewater effluents was made. If delays of tissue development appeared on effluent exposed specimens, NAGase activity was similar between the different conditions. This apparent desynchronization between tissue and molecular activities accentuates the diagnostic of moult impairment and raises the interest to use markers at different organisational levels.
اظهر المزيد [+] اقل [-]Removal Study of Hazardous Thiols Pollution by Tributylammonium Halochromates (VI) / Silica, (C4 H9) 3 NH + [CrO3 X]- , (X=F, Cl): as an Oxidizing Agent النص الكامل
2023
OICC Press Authors | Mohammad Kazem Mohammadi
Oxidative coupling of thiols to the corresponding symmetrical disulfides were performed in the presence of silica gel supported tributylammonium fluorochromate(VI), (TriBAFC), and tributylammonium chlorochromate(VI), (TriBACC). Silica gel supported TriBAFC and TriBACC are versatile reagents for the effective and selective oxidation of organic substrates, in particular of thiol, under mild conditions. Disulfides are also key intermediates in a wide variety of organic synthetic routes. Considerable improvements are observed in the presence of the absorbent and making the work-up much more convenient. The nature of the solvent does not appear to be particularly critical. Hydrocarbons, benzene, ethers and chlorinated hydrocarbons are equally effective, the practical choice being oriented by the solubility of the products and the desired reaction temperature. The IR spectra of TriBAFC and TriBACC are similar to that of other fluoro and chlorochromates, TriBAFC and TriBACC are soluble in water, dimethylformamide, acetonitrile, acetone and dichloromethane; they are only sparingly soluble in benzene, carbon tetrachloride, chloroform and hexane.
اظهر المزيد [+] اقل [-]Risk analysis of ammonia release in food refrigeration Using FTA technique and fuzzy logic النص الكامل
2023
Leila Asghariazim
The purpose of this research is to analyze the risk of ammonia release in the cold storage of one of the large food companies in Mashhad. This is an applied research that was done using FTA technique and fuzzy logic. Fuzzy logic was used to weight experts' opinions (Delphi panel). In this study, to model the consequences and calculate the collective risk using the DNV PHAST 7.2 software, the most critical conditions that have the greatest possible contribution to the release of ammonia were, respectively: lack of proper and planned maintenance; Pressure increase and failure and defects in gaskets. Also, the results showed that the rate of death, toxicity and explosion is directly related to the distance. On the other hand, the maximum amount of possible losses in the event of an explosion will be in the winter season and at a distance of 14.26 meters, and finally, 95% of the losses due to the blast wave will occur at a distance of 13.54 meters and 99% of deaths of people up to a radius of 38.89 meters, also 50% of the deaths of people from the radius of 38.89 meters to the radius of 124.93 meters, and 10% of the deaths of people from the radius of 124.93 meters to the radius of 178.53 meters, also 1 percent of deaths from the radius of 178.53 meters to the radius of 234.05 meters.
اظهر المزيد [+] اقل [-]Long-term and microstructural studies of soft clay stabilization using municipal solid waste and Nano-MgO as an Eco-Friendly Method النص الكامل
2023
Ali Ohadian | Navid Khayat | Mehdi Mokhberi
This study provides a practical solution to manage non-hazardous waste and aid the environment. The largest group of non-hazardous waste is called municipal solid waste (MSW) which can be effectively used as an alternative material in civil projects. In this research, as an alternative to traditional modification methods of soil which causes global warming, the soft clay (Clay) was chemically modified by four different percentages of MSW in soil dimensions (15%, 25%, 35%, 45%) in 28 and 120 days. The optimum percentage of MSW addition (15%) to the Clay at the curing age of 28 days increased the unconfined compressive strength (UCS) and California bearing ratio (CBR) by 1.28 and 3.34 times, respectively. Given that higher percentages of MSW reduce the UCS and CBR in the specimens, four percentages of Nano-MgO, i.e., 0.25, 0.5, 0.75, and 1% were used for stabilization. The specimens containing optimum percentages of MSW (15%, 25%) and stabilized with 1% Nano-MgO could improve UCS and CBR 2.34 and 5.59 times, respectively that results had better durability over 120-days which can be attributed to the CBR testing condition. The cause of the increase in UCS and CBR was investigated using microstructural analysis for 120 days of curing. The specimen with high durability approved the cement bond formation with Anorthite & Dolomite minerals. In conclusion, using optimum MSW and Nano-MgO effectively solved the Clay problems in suitable conditions and allowed higher percentages of MSW to be removed from the environment.
اظهر المزيد [+] اقل [-]Optimization of Aeration for Improving Performance of Hospital Wastewater Treatment Plant النص الكامل
2023
Zahra Hezarian | Ehsan Derikvand | Afshin Takdastan
The present descriptive cross-sectional study was conducted by altering the type of blowers in the wastewater treatment system of Abuzar hospital in Ahvaz during the first and second quarters (6 months). In every month, inlet raw wastewater, aeration tank one, and effluent were sampled in one week (Saturday-Friday), which resulted in harvesting a total of 42 samples. Then, they were assessed based on the techniques provided in the book entitled "standard methods for evaluating water and wastewater", and data were evaluated through employing statistical analyses. The average removal efficiency of total and organic phosphorus, phosphate, and ammonia in the effluent was respectively determined 46.47, 34.45, 18.14, and 68.49 before starting up a new aeration system, which reached 69.36, 76.21, 65.09, and 96.53 during the second period, respectively. In addition, the average concentration of nitrate varied from 21.79 to 44.11 mg/l, while that of nitrite changed from 0.04 to 0.03 mg/l. Further, an increase (39.19 to 67.19%) was observed in the average nitrogen removal efficiency in effluent. Based on the results, EAAS process was efficient in eliminating nitrogen and phosphorus by using the helicoidal pumps of aeration blowers and regulating aeration rate. Thus, aeration plays an effective role in activated sludge systems despite the microorganism diversity in aeration tank sludge. The produced effluent was consistent with Iran national standards in terms of the parameters under study, especially phosphorus and nitrogen, and can be discharged into the environment.
اظهر المزيد [+] اقل [-]Zoning and modeling of energy consumption in human settlements and explaining the effective components in the design of green buildings (Case study: Mashhad) النص الكامل
2023
Najiyeh Abavisani Joghtaee | Amir Farajollahi Rod | Mansour Yeganeh
The purpose of this study is to achieve the effective components and criteria in the design of green residential settlements with an environmental protection approach in Mashhad. The research method is applied and in terms of implementation is descriptive-analytical. Using the TM sensor and LANDSAT satellite, satellite images of the study area were prepared and modeled by superimposing data related to energy consumption through GIS tools and Arcview software to final synthesis and mapping. Then, using the opinions of experts to extract and prioritize the appropriate components and criteria from each of the mentioned systems. Data were analyzed by structural equation method with least squares approach and Smart - PLS2 software was used for final analysis. Then, after explaining the components and criteria, according to the available data, the optimal limit (10% -20%) for 10 components was proposed as a scenario. Then modeling was done through Design Builder software. The results showed that a total of 4 categories of macro variables have been identified as the main components affecting energy consumption, which are: "management", "environmental performance", "economic performance" and "social performance" variables, all of which have divergent validity. Also, 11 topics and 61 criteria were extracted and explained as components for assessing the sustainability of residential buildings. Finally, it was found that with the implementation of energy optimization strategies, the heating system will be reduced by 36%, the cooling system energy by 41% and the total cooling and heating energy by 38% compared to the base state.
اظهر المزيد [+] اقل [-]Investigation of civil responsibility for the spread of environmental pollution caused by the Coronavirus pandemic النص الكامل
2023
Shadi Shoghi Beygi | S.Ali Jozi | Mojtaba Zamani
The most important objectives of the present study include finding a legal solution to prevent the spread of coronavirus, compensation for damages caused by the negligence of human factors, determining the basis for this responsibility, and the rate of compensation for these damages. The present study, through library and field studies, made it possible to compensate for the damage caused by the spread of coronavirus infections. Pollution caused by a human is one of the most important environmental law challenges. Neglect of the human factor has caused losses due to the spread of this disease. In the present study by preparing a researcher-made questionnaire, the opinion of lawyers specializing in the field of civil responsibility was also inquired. The results of the research show that by resorting to the "risk theory" and the "fault assumption" basis, the rights of the victims of the Coronavirus can be better secured. At present, legal systems are not sufficiently determined to compensate the victims of the Coronavirus. While environmental jurists believe that strict rules and regulations should be applied to combat the spread of coronavirus infection and to impose compensation for damages caused by negligence in observing health standards on its human factors. In Iran, several juridical and legal rules are a good basis for preventing the spread of coronavirus and human infections.
اظهر المزيد [+] اقل [-]Measuring noise pollution from sports events in urban environments (case study: Azadi stadium) النص الكامل
2023
Farzaneh Taghavi Baghan | Seyed Mostafa Tayebi Sani | Nabiollah Ider | Mozhdeh Khajoo
Sound pollution is known as one of the main disturbances in urban environments. The purpose of this study is to measure the sound level during sports competitions in the vicinity of settlements. For this purpose, Azadi Sports Complex was selected as the largest sports space in the IRAN and the measurements were performed cross-sectional and in two different times, which included days without sports competition and after the end of the sports competition. Measurements were used 5 times by KIMO-DB100. All measurements were made to determine the sound pressure level in network A. The mean data (Leq) was the basis for drawing the maps. To do this, the pattern of changes was entered into the Arc map software and based on the Inverse Distance Weighting method. The results showed that the minimum sound level on the day without exercise was 50 dB and the maximum sound level measured at this time was 80 dB. On the day of the race, the minimum and maximum sound levels were 55 dB and 95 dB, respectively. On a non-racing day, large sections of the study range have sound levels of 50-65 dB, indicating relative calm and compliance with outdoor sound standards. However, on the day of the match and after the spectators left the stadium, none of the sound level stations showed less than 75 dB. This situation continues for about 3 hours after the end of the game and until the study area of spectators and their cars is completely emptied.
اظهر المزيد [+] اقل [-]Investigation of wet spraying system to control dust pollution in mines (A case study ) النص الكامل
2023
Mahmoud Makkiabadi | Sara Yaghoobi | Mohammad Saleh Haj Mohammadi
Industrial dust has a significant effect on the environment of mines, which leads to an increase in illness among workers. To decrease the impact of dust on the climate, a wet spraying system is useful for controlling dust in mining companies. In this paper, by using the wet (water) spraying system, dust control in the area of the crusher and pellet plant (discharge tower) has been investigated by Goharzamin Iron Ore company. Goharzamin Iron Ore company has an essential role producing of steel in Iran. There are a 15 million tons gyratory crusher, three iron concentrate plants with an annual capacity of 6 million tons, and a pelletizing plant with annual capacity of 5 million tons. The dust was controlled in the gyratory crusher area of Goharzamin Iron Ore company by using a wetting spraying system. Results showed that the rates of PM10 for the east, west, north and south sides of the gyratory crusher and also the center of this system are equal 851.2, 647.5, 643.9 and 781.2, and 1116.3 μg/m3, respectively. Foremore, after turning on the wet spraying system in this area, these values are reduced to 128.3, 112.8, 115.9, 123.7, and 189.9 μg/m3, respectively. The results showed that the water spray system in the gyratory crusher area reduced the PM2.5 (Particulate matter) and PM10 particles by 67% and 80%, respectively.
اظهر المزيد [+] اقل [-]Investigating the role of origami algorithm in facades of high-rise buildings to reduce visual pollution and improve urban landscape quality النص الكامل
2023
Tabbasom Tabasi | Amir Farajolahi Rod | Vahid Ahmadi | Hamid Reza Shoaei
The present study was conducted to identify and prioritize origami components affecting facades of high-rise buildings to explain the role of origami algorithm in improving urban landscape quality and reducing visual pollution. The research had an exploratory nature, and used the method of descriptive-survey data analysis. The research design was carried out in three steps, documentary analysis, Delphi survey and semiotic analysis. A panel of experts (n = 15) was considered as specialists in urban planning, architecture and urban design. Data were analyzed by statistical tests, SPSS-22 software and MAXQDA 2020 software. A hypothetical model of high-rise building made in RHINO software using Grasshopper plugin was applied for simulation. The results of the questionnaires revealed the effects of 18 components on the facade of high-rise buildings and also 12 components on the improvement of urban landscape quality. The findings indicated a correlation between overall dimensions of origami algorithm and urban landscape quality, and showed that the components of ârepetitionâ, âdetailsâ, âgeometryâ and ârhythmâ were most related to the origami algorithm, thereby highlighting the strong impact of the origami algorithm on improving urban landscape quality. According to the simulation results, among the components affecting urban landscape quality, âView compositionâ had the largest contribution with the correlation coefficient of 130, followed by âColorâ and âBalance and symmetryâ with the coefficients of 120. The end of this classification included the component âposition of openingsâ with the coefficient of 2.
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