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One of the most important sources of noise pollution in urban areas is traffic noise. The aim of the present study was to determine noise pollution in the different parts of Yazd city in 2010 and to compare them with current standard levels. In total, 135 samples were obtained from both residential and commercial areas according to the ISO 1996-2002 method in order to measure noise pressure levels. Locations included 10 streets and 5 squares of the city and the measurement times were considered in the morning, afternoon, and the evening. Noise level was determined in A-weighted by sound level meter model 2232. Results showed that the rate of background noise in Yazd city was high, as it was 71,2±4.4, 66.2±3.7, and 60.3±4 in the L₁₀, L₅₀, and L₉₀, respectively. The mean level of maximum noise pressure was 74.3 dB(A) (Lmax), and the mean continuous sound equivalent level was 66.7 dB(A) (Leq). Comparing the noise level obtained in the present study to the standard level, it can be obviously concluded that the noise levels are higher than that of acceptable levels in most parts of the city. So, different preventive countermeasures such as increasing public awareness through educational programs and technical controls for the future development of the city are crucial.
In recent years humans have endured increasing numbers of natural disasters, of which flooding is the greatest and most common throughout the world. Iran is also exposed to floods, considering the severe damage recently incurred in Golestan province, particularly Gorganroud watershed. Due to the importance of the subject and lack of comprehensive studies on flood risk in the country's watersheds, it is crucial to perform flood risk assessment using appropriate tools, such as Landsat ETM+ imaging and digital elevation model data collections in geographic information system throughout the region. For this purpose, database maps of 6 subwatersheds in Gorganroud watershed were prepared in 5 layers affecting flooding in the region. By overlaying and weighing three layers in GIS software, a layer of flood hazard intensity was obtained. Next, by means of obtained numbers and scoring, the overuse layer priorities were determined. Then, these two flooding layers were overlaid with the help of a two-dimensional matrix, and the final map of flood risk was obtained. Finally, it was found that Chelichay and Sarab Gorganroud, making up to 24.59% of the Gorganroud watershed, are the most risky sub-watersheds. In light of the fact that the data pertaining to Gorganroud watershed have never been entirely used to sort out the risk priorities in the region, the new method presented in this paper can lead to a more accurate and comprehensive understanding about what is really taking place in it.
Precise and appropriate management of farmland for a cotton crop to reach the highest water use efficiency with a low water supply and an acceptable yield is required in arid- and semiarid regions. This study in Iran aimed to find the most appropriate concentration of jasmonic acid (JA) and the best stage for application to cope with any negative impacts of water deficit stress. A split-plot factorial experiment based on a randomized complete block design with three replications was used in 2 consecutive years (2016–2017). Two irrigation intervals of 10 and 20 days were used, with four concentrations of JA (0, 25, 50, and 100 mg L−1 ) and applications at three crop stages (vegetative, reproductive, and vegetative and reproductive together). The final results showed that the 20-day interval significantly decreased relative water content, the quantity of cotton, cotton yield and its related traits including boll number per plant, the 1,000-seed weight, seed cotton yield, lint yield, and lint percentage. It also increased the content of proline and soluble sugars. The 50-mg L−1 concentration of JA applied at the vegetative-reproductive stages appropriately mitigated the negative effects of water deficit. These results are of practical application for farmers in arid- and semiarid regions with low water supply when irrigating cotton lands in order to reach an acceptable cotton yield.
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