Search

The mechanism of noise pollution propagation is considerably affected by 1) the type and configuration of its receiving environment and 2) the distance that sound waves pass to reach that environment. This study adopts a spatio-statistical approach to quantify and model associations between noise pollution levels and landscape metrics of land categories (built-up structures and urban green covers). Accordingly, noise levels were measured employing a sound pressure meter to quantify equivalent levels (Leq in dB A), in addition to their corresponding percentiles (L10 and L90). A collection of 30 sampling points were selected to measure noise data within the fall season and between 4 p.m. and 8 p.m. hours of the day. A hierarchical distance-sampling framework based on buffer areas with different radius (300 m, 600 m and 1 km) around each sampling point was compiled to measure composition and configuration metrics of land categories within each buffer area. The results derived from Pearson correlation analysis and multiple-linear regression models indicated that there is a distance-dependent relationship between the metrics of green areas and noise levels. We didn’t find remarkable distance-dependency between built-up structures and noise levels. Based on our new spatio-statistical approach, we conclude that more connected and compacted pattern of green areas closer to pollution centers can significantly alleviate the effects of noise propagation mechanism and appropriate pattern of built-up areas follows a low density distribution with coming green areas in between. Findings of this study highlight the potential of landscape ecology approach as an effective planning paradigm for designing greener and calmer cities.

Nowadays a wide range of options of vehicles fuels and technologies are commercially available. Still, the complicated nature of environmental impacts caused by each option makes it a tough decision for the consumer, fleet manager, or policy maker to find the best choice. Even policy makers may run into trouble regarding the relative advantages of cleaner options and their relative effects on fuel and vehicle cycle. In light of these, the present paper is an attempt to evaluate the life cycle environmental impacts of road vehicle fuels and available technologies and compare the cleaner options with each other and the main stream fuel/technologies. A complete fuel life cycle assessment (LCA) on petrol, diesel, compressed natural gas (CNG), electric vehicle (EV), hydrogen fuel cell vehicle (FCV), and biodiesel vehicles was made. Results are shown for climate change, air quality effects and Energy resource depletion impact of the different vehicle technologies. As recommended by the results, none of the options dominated the others regarding all dimensions. Instead of mandating a particular solution, such as electric cars or biofuels, probably successful vehicle and fuel policies include established standards of performance and levies to attenuate emissions and let the market to find the best effective alternative.

Understanding, analysis, monitoring and modeling of urban growth evolution as a major driving force of land use/land cover transformation, especially in developing countries, is of great importance for land managers in the process of sustainable development. Using spatial predictive models and change detection techniques can provide an additional level of knowledge of the causes and impacts of urban growth mechanisms, which finally provide comprehensive insight into urban chronology. Karaj, the capital of Alborz province, has been experiencing a substantial increase in total area of urban environments mainly due to its socioeconomic attractions during the last three decades. The present work aims to reveal how the historical trend of the urban growth can affect its future spatial pattern. For conducting this study, the SLEUTH cellular automata urban growth model was executed via three calibration steps including coarse, fine and final. Relying on the calibrated model, dynamics of the Karaj City were predicted under its historical trend as well as two different scenarios including compact and extensive growth up to year 2040. According to the findings of the present study, while extensive growth option indicates the most consumption of the vacant lands, the compact scenario dictates infill form of the urban growth in addition to saving spaces. Finally, urban growth forecasting based on its historical trend illustrates that total area of the human-constructed elements will be in the middle of other two predictive scenarios.

Sustainability analysis of urban complex systems, as an interdisciplinary study, necessitates integrative modeling approaches for analyzing relationships between land parameters and landscape patterns. The present paper emphasizes applicability of dynamic and scenario-based investigation of urban environments for understanding the interactions between urbanization suitability and landscape pattern. Combining parameter modification and model integration approaches for introducing growth alternatives, a basis was established for detailed assessment of the Karaj urban context, Iran. SLEUTH’s probabilistic images of future urbanized lands of two growth scenarios (historical trend-based urban growth and compact urban growth) were simultaneously employed as dynamic factors for urbanization suitability mapping and landscape pattern analysis of the years 2011, 2020, 2030 and 2040. Findings of the present studies showed while historical trend-based urban expansion occupied more land resources, this growth option resulted in a more manageable pattern of urban landscape in terms of its connectivity and compactness as well as possessing higher urbanization suitability index across the study time frame. This study addresses utility of scenario-based analysis of urban areas that furnishes urban planners with insights into cumulative impacts of an ongoing urbanization process under different environmental circumstances.

Population growth and an increase in the quantity of municipal solid waste have made it ever more difficult to locate appropriate sites for waste disposal in urban areas. Transfer stations are used for landfills located far from waste generation centers, but they generate noise, offensive odors, and dirt that give rise to dissatisfaction of neighbors. This study identified suitable waste transfer stations for Mashhad City, Iran. A multi-criteria evaluation (MCE) model for assessing suitability of land for solid waste transfer stations was developed. The criteria for site selection included soils, geology, slope, and distance to residential areas, waste generation centers, streams, faults, and highways. Each of the criteria used in the MCE was standardized with a fuzzy subset, and a linear function was used to rank each criterion. Relative importance of each criterion was calculated using the pairwise comparison method. A weighted linear combination method was used for spatial multi-criteria layer combination. Twelve zones ranked in descending order are proposed for transfer stations. The MCE results also provided a first-cut information layer for a fast environmental impact assessment. The nature of MCE, being repeatable as many times as desired, makes consensus building among stakeholders possible. The results can be used by decision makers for site selection of the waste transfer stations after taking into account other relevant ecological and economic factors.

Breeding success of the Arabian/Indian race of the Western Reef Heron Egretta gularis schistacea was studied in the Hara Biosphere Reserve, Persian Gulf, during 2008 and 2009, with 103 and 137 nests studied, respectively. Marked nests were checked at least twice a week to note egg-laying date, clutch size, brood size, egg loss and chick mortality. Also, hatching and breeding success were estimated. Egg-laying was from 21 March to 17 April in 2008 and from 28 March to 28 April in 2009. Mean clutch size in the two years combined was 3.4 ± 0.05 and significantly greater in 2009 (3.5 ± 0.07) than 2008 (3.2 ± 0.07). Mean brood size was 2.0 ± 0.1 for all clutches and was greater in 2008. The internal diameter of nests, the height of nests from the ground and the distance of nests from the mangrove forest border were important factors influencing breeding success. The percentage of successful nests varied significantly between the two years (80% in 2008 and 51% in 2009). Overall, approximately 64% of n...

Mashad is the capital city of Khorasan Razavi Province, in the North East of Iran. The city has witnessed rapid growth in the last two decades, mostly because of its economic, social and religious attractions. We implemented this study to understand Mashad City growth dynamics, to forecast its sprawl for the next two decades and to provide a basis for urban management. We used the SLEUTH urban growth simulation and forecasting model. We calibrated it with historical data derived from a time series of satellite images. Three scenarios were designed to simulate the spatial pattern of urban growth under different conditions. The first scenario was historical urban growth, which allowed continual urban area expansion, similar to historical trends, without any limitation. The second scenario was environmentally-oriented in which urban growth was limited. The third scenario was a specific compound urban sprawl situation in which growth was allowed to continue, similar to the historical trend, but a limitation was applied to construction on steeper slopes. The results showed the utility of the modeling method in explaining the spatial pattern of urban growth. The result of the second scenario illustrated that valuable land in suburban areas, including flourishing farms, could be saved. Urban growth under the third scenario showed the harnessing effect of slope-limited growth. We conclude that the results of the modeling under the three scenarios for Mashad City growth are of great potential use to city managers. We also showed that the environmental scenario is preferable for Mashad City development.

We report on high efficiency resonant doubling at 486nm using periodically poled KTP. A stable blue power of 700 ± 5 mW was obtained using the 840 mW output power of a FBG stabilized PM fiber coupled IR semiconductor laser. This gives an overall conversion efficiency of 83%. To obtain this result, all losses in the system were carefully studied and minimized.

Pigeon pea [Cajanus cajan] is an important grain legume of South-East Asia and East Africa. It is mainly grown as a kharif crop and is known to sustain prolonged drought and temperature stress. The Hsp 100family gene [ClpB] is one of the major and critical genes required for acquired thermo tolerance. The current study was taken up to identify and characterize the Hsp 100 family genes in pigeon pea since very little information is available for this thermo tolerant plant. In silico genome wide characterization was carried out and 5 Hsp100 like gene sequences were identified. Domains were predicted and three proteins were found to possess Class I type ClpB domains. Expression of these genes was observed at control 2, 6 and 24 h post heat stress conditions indicating their heat inducible nature. Out of the 5 genes predicted, two Clp genes show constant expression under heat stress and could be important components of the heat stress response in pigeon pea as they are targeted to the chloroplast. To identify additional members, candidate gene approach was taken up. Glycine max Hsp100 genes were downloaded and their expression studied under heat stress conditions in Asha, Pusa dwarf and C. platycarpus genotypes. Out of 23, 20 genes were expressed in pigeon pea indicating the presence of more Hsp100 family genes in the genome that need further investigation. This study would help in understanding the molecular components governing thermo tolerance in pigeon pea.

We report on high efficiency resonant doubling to 486 nm using periodically poled KTP. The IR laser source is an FBG stabilized semiconductor laser with a maximum polarization maintaining (PM) fiber coupled output of 840 mW. An output power of 680 mW at 486 nm was obtained from our optimized cavity, giving net efficiency of 81%. Also, we report an 87.5% net efficiency in coupling of this blue light from the servo locked cavity into a single-mode PM fiber. This gives a total of 71% fiber to fiber efficiency. Furthermore, a wall plug efficiency of 21.4% was obtained.

I have been asked to speak on a difficult subject. I accepted the invitation not because I feel equal to the task but because I believe that, for a proper appreciation of the several problems that the Indian society is presently facing, we must understand the nature of the underlying class conflict. This sounds very Marxian.