Effect of Microwave Irradiation on the Dielectric Characteristics of Semi-Conductive Nanoparticle-Based Nanofluids: Progress towards the Microwave Synthesis

Studies on dispersing nanoparticles in base fluid to elevate its essential and critical properties have evolved significantly in the recent decade. Alongside the conventional dispersion techniques used for nanofluid synthesis, microwave energy at 2.4 GHz frequency is irradiated onto the nanofluids is experimented with in this study. The effect of microwave irradiation on the electrical and thermal properties of semi-conductive nanofluids (SNF) is investigated and presented in this article. Titanium dioxide and zinc oxide are the semi-conductive nanoparticles used for this study to synthesize the SNF, viz., titania nanofluid (TNF) and zinc nanofluid (ZNF). Flash and fire points are the thermal properties verified, and dielectric breakdown strength, dielectric constant ((Formula presented.)), and dielectric dissipation factor (tan (Formula presented.)) are the electrical properties verified in this study. AC breakdown voltage (BDV) of TNF and ZNF is improved by 16.78% and 11.25%, respectively, more than SNFs prepared without microwave irradiation. Results justify that the synergetic effect of stirring, sonication, and microwave irradiation in a rational sequence (microwave synthesis) exhibited better electrical and unaltered thermal properties. This microwave-applied nanofluid synthesis could be a simple and effective route to prepare the SNF with improved electrical properties

Growth rings in tropical trees : role of functional traits, environment, and phylogeny

Acknowledgments Financial support of the Centre National de la Recherche Scientifique (USR 3330), France, and from the Rufford Small Grants Foundation (UK) is acknowledged. We thank the private farmers and coffee plantation companies of Kodagu for providing permissions and logistical support for this project. We are grateful to N. Barathan for assistance with slide preparation and data entry, S. Aravajy for botanical assistance, S. Prasad and G. Orukaimoni for technical inputs, and A. Prathap, S. Shiva, B. Saravana, and P. Shiva for field assistance. The corresponding editor and three anonymous reviewers provided insightful comments that improved the manuscript.Peer reviewedPostprin

Data Paper – High Resolution Vegetation Cover Data for the Southern Western Ghats of India. (IFP_ECODATA_VEGETATION)

This data paper has been prepared following the Ecological Metadata format proposed by Michener et al. (1997). It is accompanied with data archives downloadable from the IFP Biodiversity Portal at http://www.ifpindia.org/biodiversityportal/The Western Ghats form a 1,600 km long escarpment that runs parallel to the southwestern coast of Peninsular India. This relief barrier, which orographically exacerbates the summer monsoon rains, is responsible for steep bioclimatic gradients that have long been recognized as one of the major ecological determinants for the forest vegetation of the region. We report here girded vegetation data at 30' lat/long (ca. 1 km) resolution that cover an area of about 70,000 km2 of the southern Western Ghats, between 74 to 78° E and 8 to 16° N. These data have been extracted from: the 1:250,000 scale forest maps of South India published by the French Institute of Pondicherry (FIP), which have been digitized and simplified; the 2004 MODIS (Moderate Resolution Imaging Spectroradiometer) database, for the IGBP (International Biosphere Geosphere Programme) global vegetation Land Cover Type and Normalized Difference Vegetation Index (NDVI) of March 2004

Socio-economic assessement of farmers' vulnerability as water users subject to global change stressors in the hard rock area of southern India. The SHIVA ANR project

International audienceDemand for vulnerability assessments is growing in policy-making circles, to support the choice of appropriate measures and policies to reduce the vulnerability of water users and resources. Through the SHIVA ANR project, we are seeking a method to assess and map the vulnerability of farmers in southern India to both climate and socioeconomic changes, and secondly, to assess the costs and benefits associated with trends farmers' vulnerability in the medium and long-term. The project is focusing on southern India 's hard rock area, as in the geological context, both surface and ground water resources are naturally limited. We are also focusing on farming populations as these are the main water users in the area and rely exclusively on groundwater. The area covers southern India's semi-arid zone, where the rainfall gradient ranges from 600 mm to 1100 mm. Vulnerability is expected to vary according to local climatic conditions but also the socioeconomic characteristics of farming households. The SHIVA research team has been divided into six thematic groups in order to address the different scientific issues : downscaling the regional climate scenario, farm area projections, vulnerability assessments and quantification, vulnerability mapping, hydrological modelling and upscaling, and vulnerability impact assessements. Our approach is multidisciplinary to cater for for numerous inherent themes, and integrated to cater for vulnerability as a dynamic and multidimensional concept. The project 's first results after 10 months of research are presented below

Climate change research (1991–2012): comparative scientometric study of Argentina, Brazil, China, India and Mexico

This paper attempts to highlight quantitatively the growth and development of climate change literature in terms of publication output as per Web of Science® (1991–2012, September).The focus of this analysis is to study the literature on climate change published from five developing countries namely Argentina, Brazil, China, India and Mexico. This paper is a comparative study on year wise, document type, most productive authors, subject wise, journal wise, institution wise, and language wise distributions. 7065 records have been retrieved for climate change for the studies countries. Country-wise climate change records and most prolific authors for the five countries have been identified. Authorship and collaboration trend was towards multi-authored papers. Institution-wise climate change records for these countries have also been generated. The topper here is Chinese Academy of Science, China (1843 records). We have grouped the listed publications from Web of Science® under “climate change” into six broad subjects among which “Geosciences (multidisciplinary)” has recorded maximum publications (22.4%) followed by “Environmental Sciences” (21.6%) while “Meteorology and atmospheric sciences” has recorded the least (9.3%). English language occupies the first place with 6882 out of 7065 records for the studied countries

Data paper : high-resolution topographic and bioclimatic data for the Southern Western Ghats of India (IFP_ECODATA_BIOCLIM)

The Western Ghats form a 1,600 km long escarpment that runs parallel to the southwestern coast of Peninsular India. This relief barrier, which orographically exacerbate the summer monsoon rains, is responsible for steep bioclimatic gradients that have long been recognized as one of the major ecological determinants for the forest vegetation of the region. We report here gridded topographic and bioclimatic data at 30' lat/lon (ca. 1 km) resolution that cover an area of about 70,000 km2 of the southern Western Ghats, between 74 to 78° E and 8 to 16° N. These data have been extracted from three main sources: the SRTM (NASA Shuttle Radar Topography Mission) 90 m Digital Elevation Data, version 4 (http://srtm.csi.cgiar.org/) from which were secondarily derived aspect and slope; a digitized version of the bioclimatic maps of the Western Ghats by Pascal (1982) based on various sources of long series of climatic records over the period 1950-1980, from which were derived annual rainfall, mean temperature of the coldest month and dry season length; the WORLDCLIM database, version 1.4 (http://www.worldclim.org/), which provides monthly interpolated rainfall and temperature data from series of at least 10 years records over the 1950–2000 period. Key-words: Digital Elevation Model, India, long-term bioclimatic interpolations, SRTM, Southern Western Ghats, WOLDCLIM

Heritage conservation and environmental threats at the 192-year-old botanical garden in Pondicherry, India

International audienceUrban botanical gardens conserve historical flora, improve the local environment and promote human well-being. Unfortunately they are often undervalued due to lack of public awareness or resources. Analysis of species diversity and turnover at long-lived gardens can improve the understanding of long-term plant resilience and help adapt management actions to align with rapidly changing urban contexts. Given the various threats faced by urban botanical gardens, we examined tree species diversity, historical changes and survival of plants at the Botanical Garden in Pondicherry (BGP), southern India, which was established 192 years ago by the colonial French government.A complete census of trees was carried out to compare current species diversity with two historical lists compiled 151 years ago and 57 years ago, respectively. These lists were also used to identify heritage trees. Effects of environmental threats, including the very severe cyclonic storm Thane (December 2011) and various damages to young stems, were analysed with Google Earth images and field inventories.There were 284 identified tree species, including 25 endangered/vulnerable/threatened species and 53 tropical dry evergreen forest species. Turnover had occurred, and approximately half of the historical species had been replaced with new species. Tropical Cyclone Thane caused severe damage to large trees and anthropogenic activities damaged saplings. Yet, at least 65 large resilient individuals had survived all the threats, and signifiy the adaptability and heritage value of the BGP.Our study revealed multiple values of this heritage green space in a rapidly developing South Asian city and suggests strategies for modernisation that are aligned with international conservation guidelines. We recommend better monitoring and utilisation of cyclone-damage data to guide future plant introductions at this coastal site

Potential and limists of satellite-derived digital surface model data for assessing flood risks in Southeast Coast of India

International audienceFlood risk assessment in low-lying coastal areas requires efficient spatial observations of land elevation for theimplementation of protection, evacuation and safeguard plans of people and assets. Here we evaluated the potentialof Digital Surface Model (DSM) derived from satellite observations to map flood prone areas with the objective ofearly warning on flood risk in the Cuddalore and Pondicherry region, southeast coast of India. Coastal zonemanagement of this 100 km long coast is particularly challenging. Indeed, the whole region experiences at leasttwo cyclonic storms accompanied with storm surge, heavy rains, flooding and beach erosion every year; the havocswreaked by the 2004 tsunami, flash floods of 2005 and 2015, and the Thane cyclone in 2011 are still closememories. We analyzed Sentinel-1 Synthetic Aperture Radar (SAR) and ALOS World 3D DSM satellite data, andGoogle Earth images. All these data are freely available and we compared them to the population census dataacquired in 2011. Using Sentinel-1 SAR images, we discriminated flooded from non-flooded areas before comparingmaps of low-lying areas derived from ALOS DSM data. The results suggest a good agreement between real floodedareas and low-lying areas. However, the micro-topography reflecting channels and drainage systems could not becaptured with important issue for delineating areas with high risks of flooding. We explained that spatial resolutionof about 2 m in X, Y and 10 cm in Z directions are necessary for identifying areas with high risk of flooding asdemonstrated in many countries of the world. It is time to rethink national Indian spatial policy about high-resolutionimages in order to prepare safety plans of the property and the lives of populations of Tamil Nadu coasts

Mapping Spatial Changes in the Pichavaram mangrove from 2003 Onwards Using Very High Resolution Images, Tamil nadu Coast, India

International audienc

Decadal evolution of a spit in the Baram river mouth in eastern Malaysia

We studied a newly formed spit in the Baram River mouth in Eastern Malaysia and evaluated the effects of climatic conditions and human interference over the last four decades (1974-2014). The development of a spit during a decade (1998-2008) and its maximum expansion over the period 2005-2010 is related to the erosion associated with deforestation and land use changes in the upstream region. The downstream transportation of the heavy sediment load occurred during the events of higher precipitation and flash floods. The recent spit was identified for the first time as a mud flat post the flash flooding of January 2005. It extended towards the south west of the river mouth till 2010 (six fold increase in area from 2005 to 0.29km<sup>2</sup>) and gradually disintegrated over the next 3 years. Depositional feature of coarse sediments and organic debris is clearly supported by the alternating thick layers in the top 25cm of the three core samples (C1-C3) collected from the region. The non-existence of finer particles clearly indicates the supremacy of long shore currents in the region carrying away the fines to deeper regions. Gradual disappearance of the sand barrier post 2011 is due to the reduction in the amount of sediment load as a result of reduction in recent rainfall activity, land use/land cover changes mainly as reforestation, strengthening of palm plantation (controlling soil erosion in the river banks) in the upstream region. The dominant NW wind direction during the major part of the year is also one of the factors for the shift in depositional sequence and it is helped by the long shore currents which lead to the spit being partially connected to the main land