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Sharma S.,Pandit Ravishankar Shukla University | Sharma S.,Government Kamla Devi Girls College | Giri B.,Kathmandu Institute of Applied science | Patel K.S.,Pandit Ravishankar Shukla University
Journal of Atmospheric Chemistry | Year: 2016

Volatile organic compounds (VOCs) are an important group of compounds because of their role in atmospheric chemistry and the risk they pose to human health and ecosystem. Therefore, the interest in determining VOCs in the atmosphere has increased over the last few decades to understand their emission, distribution, and sources. Considering the expanding urbanization and increasing use of fuels, very limited data of VOCs in India is available. This paper describes the chemical analysis of 12 light VOCs in 144 ambient air samples collected from three different sites near Raipur, India during a period of April, 2006-March, 2007 in order to understand their temporal and spatial distributions. This data has provided some important insights into the VOC profile, for the first time, of an industrial area in India. The annual average concentrations of all 12 VOCs in our study ranged from 43.2 to 160.4 μg m−3 (mean: 95.6 ± 31.0). The annual average concentration of individual VOCs in Raipur region ranged from 3.4 μg m−3 for xylenes to 18.3 μg m−3 for n-butane. n-Butane, i-butane, and propane were the three most abundant pollutants among all of the VOCs measured. The observed concentrations of these compounds in Raipur region were comparable to other Asian cities with some exceptions. The levels of total VOCs showed seasonal variations with a statistically significant winter maximum and lower values during summer and monsoon ranging from 55.9 ± 9.9 μg/m3 in August to 144.5 ± 15.5 μg/m3 in January. Sources of these VOCs have been described using species ratios and correlation studies. © 2016 Springer Science+Business Media Dordrecht


Neupane B.,University of North Carolina at Chapel Hill | Neupane B.,North Carolina State University | Neupane B.,Kathmandu Institute of Applied science | Chen F.,North Carolina State University | And 4 more authors.
ChemPhysChem | Year: 2016

Early studies showed that the adsorption of nanorods may start from a special “anchored” state, in which the nanorods lose translational motion but retain rotational freedom. Insight into how the anchored nanorods rotate should provide additional dimensions for understanding particle–surface interactions. Based on conventional time-resolution studies, gold nanorods are thought to continuously rotate following initial interactions with negatively charged glass surfaces. However, this nanosecond time-resolution study reveals that the apparent continuous rotation actually consists of numerous fast, intermittent rotations or transitions between a small number of weakly immobilized states, with the particle resting in the immobilized states most of the time. The actual rotation from one immobilized state to the other happens on a 1 ms timescale, that is, approximately 50 times slower than in the bulk solution. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


Paudel P.K.,Nepal Academy of Science and Technology | Paudel P.K.,Kathmandu Institute of Applied science | Heinen J.T.,Florida International University
Applied Geography | Year: 2015

Landscapes consisting of heterogeneous environmental conditions (e.g. elevational gradients) are richer in species diversity than more homogeneous landscapes. Furthermore, the importance of heterogeneous landscapes has been widely acknowledged in biodiversity conservation due to expected elevational shifts in ranges as a result of climate change. This is especially important in mountainous landscapes. There is as yet no protocol that conservation planners can use to integrate landscape heterogeneity in the design of protected area (PAs) systems. In this study, we tested whether Nepal, as a whole, consists of highly heterogeneous landscapes in term of elevation, and whether heterogeneity of PAs is correlated with their size and species diversity. We developed a conservation index of elevational zones within Nepal to evaluate their representativeness in the protected area system. The results showed that, in Nepal's PAs, indices of elevational heterogeneity were strongly associated with species richness. However, heterogeneity indices were not strongly associated with sizes of PAs despite the fact that Nepal is a highly heterogeneous country. The same is true for national parks and conservation areas based on IUCN-The World Conservation Union's categories of PAs. The conservation index of elevation zones suggested a bias in reserve selection towards higher elevations. There is an urgent need to rectify past biases in reserve design so as to ensure protection of elevational heterogeneity during conservation planning, especially in these times of human-induced climate change. © 2014 Elsevier Ltd.


Paudel P.K.,Nepal Academy of Science and Technology | Paudel P.K.,Kathmandu Institute of Applied science | Sipos J.,University of Ostrava
Global Ecology and Conservation | Year: 2014

Understanding diversity patterns along altitudinal gradients, and their underlying causes are important for conserving biodiversity. Previous studies have focused on climatic, energetic, and geographic variables (e.g., mid-domain effects), with less attention paid to human-induced habitat modifications. We used published data of bird distributions along an elevational gradient (0-4900m) in the Nepalese Himalaya and interpolated species presence between elevational limits. The relationship between species richness and environmental variables was analyzed using generalized linear models. A low plateau relationship between bird richness and elevation was observed, with a main peak at intermediate elevations (2800m). Across the total gradient, interpolated bird species richness had a unimodal relationship to maximum monthly precipitation and a linear response to seasonal variation in temperature, proportion of forest cover, and proportion of protected area. In lower elevations (0-2800m), interpolated species richness had a positive and linear response to the proportion of Ramsar sites and a unimodal response to habitat heterogeneity. At higher elevations (2900-4900m), interpolated bird richness had a positive linear response to monthly variation in temperature and a negative linear response to proportion forest cover. We conclude that factors related to human management are important drivers of elevational gradients in bird species richness. © 2014 The Authors.


Paudel P.K.,Academy of Sciences of the Czech Republic | Paudel P.K.,University of South Bohemia | Paudel P.K.,Kathmandu Institute of Applied science | Hais M.,University of South Bohemia | And 2 more authors.
Zoological Studies | Year: 2015

Background: Determining the distribution of species and of suitable habitats is a fundamental part of conservation planning. We used slope and ruggedness of the terrain, forest type and distance to the nearest village to construct habitat suitability maps for three mountain ungulates (barking deer (Muntiacus muntjak), Himalayan goral (Naemorhedus goral) and Himalayan serow (Capricornis thar)) in the midhills of western Nepal. We used locations of sightings and signs of presence of these mountain ungulates collected during surveys along transect to derive a suitability value for each variable using Jacob’s index. A multiplication approach was used to combine environmental variables and produce a habitat suitability map for each of the three species. An independent dataset was used to evaluate the maps using Boyce’s index. This approach provides an overview of the probable distributions of the species in question. Results: We predict that of the total area studied, 57% is suitable for M. muntjak, 67% for N. goral and 41% for C. thar. Although there are suitable habitats for all three species throughout the study area, the availability of high-quality habitats for these species varied considerably. Conclusions: Suitable habitats for N. goral and C. thar were fragmented and mostly confined to the southern and northern parts of the study area. This study provides important baseline information for conservation biologists concerned with maintaining biodiversity in the midhills of Nepal. © 2015 Paudel et al.

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