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41.
Mohammad Sadegh Sekhavatjou Ali Rostami Azam Sadat Hoseini Alhashemi 《Environmental monitoring and assessment》2010,163(1-4):467-476
Tehran is one of the megacities of the world with a population of over eight million. Its air is highly polluted mainly due to the suspended particulate matters, which encompasses a wide spectrum of chemical elements. These elements based on their type, size, and impact on the life cycle have various environmental and heath risks. In this research, the neutron activation method is used to determine the concentration levels of Al, Ba, Fe, Mg, and V in the urban air. Thus, two districts of Tehran with different characteristics are selected. District 21 includes much of the industries located in Tehran metropolitan and is considered as an industrial area. In contrast, district 22 lacks any significant industrial activity. It is a newly established and expanding district adjacent to district 21 with a great deal of constructional activities. For the measurement of the suspended particulate matters in the air, the various sections of the aforesaid districts with industrial, residential, heavily congested traffic, residential/commercial, residential/heavily congested traffic, and residential/industrial classifications were identified. Subsequently, 24 sampling stations were selected. The sampling of the suspended particulate matters was conducted with the aid of a high volume pump containing 125 mm cellulose filters in two different time intervals. After completion of the sampling process, the samples were prepared and sent to the research reactor of the Iran Nuclear Energy Organization for Neutron Activation. During the next steps, the radiations emitted from the samples were registered, the radiation curves were plotted, and the amounts of the trace elements were determined. As a result, the average concentration levels of Al, Ba, Fe, Mg, and V were identified to be 3.301140, 2.273658 × 10, 4.0681696 × 10???1, 3.5525475 × 10???1, and 3.04075 × 10???2 μg/m3, respectively. Moreover, the emission sources of the aforesaid elements into the air were identified. The concentration levels of these elements in the industrial and heavily congested traffic sections were higher. Finally, it was concluded that the statistical analysis of these elements presents a meaningful correlation among them. 相似文献
42.
Comparison between Hansen-Hurwitz and Horvitz-Thompson estimators for adaptive cluster sampling 总被引:1,自引:0,他引:1
Mohammad M. Salehi 《Environmental and Ecological Statistics》2003,10(1):115-127
Thompson (1990) introduced the adaptive cluster sampling design. This sampling design has been shown to be a useful sampling method for parameter estimation of a clustered and scattered population (Roesch, 1993; Smith et al., 1995; Thompson and Seber, 1996). Two estimators, the modified Hansen-Hurwitz (HH) and Horvitz-Thompson (HT) estimators, are available to estimate the mean or total of a population. Empirical results from previous researches indicate that the modified HT estimator has smaller variance than the modified HH estimator. We analytically compare the properties of these two estimators. Some results are obtained in favor of the modified HT estimator so that practitioners are strongly recommended to use the HT estimator despite easiness of computations for the HH estimator. 相似文献
43.
Alipour Nima Nazari-Shirkouhi Salman Sangari Mohamad Sadegh Vandchali Hadi Rezaei 《Environmental science and pollution research international》2022,29(55):82812-82826
Environmental Science and Pollution Research - There are four paradigms of lean, agile, resilient, and green (LARG) which can promote human resource culture to create novel ideas and increase... 相似文献
44.
Kassaei Farshid Ghodsi Amirhosein Jadidi Amir Mohammad Valipour Mohammad Sadegh 《Environmental science and pollution research international》2022,29(49):73842-73855
Environmental Science and Pollution Research - Solar chimneys are among relatively modern mechanisms in the field of renewable energy which can be employed for power generation or indoor... 相似文献
45.
Dabaghian Neda Tavakkoli-Moghaddam Reza Taleizadeh Ata Allah Moshtagh Mohammad Sadegh 《Environment, Development and Sustainability》2022,24(3):3165-3197
Environment, Development and Sustainability - By developing markets and increasing world competition, today, companies' success is not only related to their performance but also the interaction... 相似文献