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SO2 Oxidation Efficiency Patterns during an Episode of Plume Transport over Northeast India: Implications to an OH Minimum  [PDF]
Timmy Francis, Shyam Sundar Kundu, Ramabadran Rengarajan, Arup Borgohain
Journal of Environmental Protection (JEP) , 2017, DOI: 10.4236/jep.2017.810071
Abstract: Systematic monitoring of the fluctuations in atmospheric SO2 oxidation efficiency—measured as a molar ratio of SO42- to total SOx (SOx=SO2+SO42-), referred as S-ratio—have been performed during a major long range plume transport to northeast India (Shillong: 25.67°N, 91.91°E, 1064 m ASL) in March 2009. Anomalously low S-ratios (median, 0.03) were observed during the episode—associated with a cyclonic circulation—and the SO42- and SO2 exhibited unusual features in the ‘relative phase’ of their peaks. During initial days, when SO2 levels were dictated by the long range influx, the SO42- and SO2 variabilities were in anti-phase—for the differing mobility/loss mechanisms. When SO2 levels were governed by the boundary layer diurnality in the latter days, the anti-phase is explained by a ‘depleted OH level’—major portion being consumed in the initial period by the elevated SO2 and other pollutants. Simulations with a global 3D chemical transport model, GEOS-Chem (v8-03-01), also indicated ‘suppressed oxidation conditions’—with characteristic low S-ratios and poor phase agreements. The modelled OH decreased steadily from the initial days, and OH normalized to SO2—referred as OHspecific—was consistently low during the ‘suppressed S-ratio period’. Further, the geographical distribution of modelled OH showed a pronounced minimum over the region surrounding (20°N, 95°E) spanning parts of northeast India and the adjacent regions to the southeast of it—prevalent throughout the year, though the magnitude and the area of influence have a seasonality to it—with significant implications for reducing the oxidizing power of the regional atmosphere. A second set of measurements during January 2010—when prominent long range transports were absent—exhibited no anomalies, and the S-ratios were well within the acceptable limits (median, 0.32). This work highlights the GEOS-Chem model skill in simulating/detecting the ‘transient fluctuations’ in the oxidation efficiency, down to a regional scale.
Spatial Variability and Radiative Impact of Aerosol along the Brahmaputra River Valley in India: Results from a Campaign  [PDF]
Shyam Sundar Kundu, Arup Borgohain, Nilamoni Barman, Meenakshi Devi, P. L. N. Raju
Journal of Environmental Protection (JEP) , 2018, DOI: 10.4236/jep.2018.94026
Abstract: The first ever land campaign to study the spatial variability of the aerosol characteristics along the Brahmaputra river valley (BRV) in Assam, North-Eastern India, was conducted during 2011. Measurements were made over 13 locations for Aerosol Optical Depth (AOD), scattering coefficient, particulate matter, black carbon (BC) concentration and meteorological parameters. The BRV is divided into three sectors longitudinally viz western sector (WS), central sector (CS), and eastern sector (ES). Significant Spatial heterogeneity in AOD and BC concentration was observed (p < 0.05) with the highest values over WS and a continual decrease from WS to ES with aerosol dominance in PM2.5 category along the entire valley. The Angstrom coefficient measured using different wavelength pairs showed spatial variability indicating dominance of fine particles over WS and coarse particles in ES with a probable bimodal distribution. The scattering and absorption coefficient shows dominance of both types of aerosol over WS than other areas. The shortwave radiative forcing was higher over the WS than CS and ES of the valley. The campaign revealed that under favorable wind conditions, the BRV is loaded with significant amount of natural and anthropogenic aerosol during local winter and is influenced by the long-range transport of aerosols from the Indo-Gangetic plain.
Funding For Development Of Infrastructure In The College Libraries In Murshidabad District (wb) And Associated Problems
Niti Mollah,A K M Anwaruzzaman,Shyam Sundar Kundu
Golden Research Thoughts , 2012, DOI: 10.9780/22315063
Abstract: College libraries in the district of Murshidabad started its journey way back in 1853. So far during the long period of over 150 years, libraries have witnessed ups and downs in terms of available finance leading to shortage of manpower and also infrastructure etc. Often libraries are found not equipped with modern gadgets and trained manpower. Even paucity of physical infrastructure such room space, etc. is evident from the study. Number of books available per student, annual expenditure incurred on running the library is found to be pathetically low. Sometimes libraries are not equipped with basic and 'must have' facilities in the age of ITrevolution such as internet links and thus facility of access to online publications and resource sharing etc. is a distant dream. Lack of books, journals and periodicals, lack of reprographic facility as well as internet etc. are the major cause of concerns expressed by the user.
A Green and Reliable Internet of Things  [PDF]
Shyam Sundar Prasad, Chanakya Kumar
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.51B011
Abstract: Internet of Things (IoT) is innovation in the field of Communication where a number of intelligent devices are involved sharing information and making collaborative decision. IOT is going to be a market-changing force for a wide variety of real-time monitoring applications, such as E-healthcare, homes automation system, environmental monitoring and industrial automation as it is supporting to a large number of characteristics and achieving better cost efficiency. This article explores the emerging IoT in terms of the potential Energy Efficiency Reliability (EER) issues. This paper discusses the potential EER barriers with examples and suggests remedies and techniques which are helpful in propelling the development and deployment of IoT applications.
Antimony Toxicity
Shyam Sundar,Jaya Chakravarty
International Journal of Environmental Research and Public Health , 2010, DOI: 10.3390/ijerph7124267
Abstract: Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The major toxic side-effects of antimonials as a result of therapy are cardiotoxicity (~9% of patients) and pancreatitis, which is seen commonly in HIV and visceral leishmaniasis co-infections. Quality control of each batch of drugs produced and regular monitoring for toxicity is required when antimonials are used therapeutically.
Liposomal amphotericin B and leishmaniasis: Dose and response
Sundar Shyam,Chakravarty Jaya
Journal of Global Infectious Diseases , 2010,
Abstract: Liposomal amphotericin B has been used with increasing frequency to treat visceral leishmaniasis (VL). It is the treatment of choice for immunocompetent patients in the Mediterranean region and the preferred drug for HIV/VL co-infection. Although there is a regional variation in the susceptibility of the parasite a total dose of 20 mg/kg is effective in immunocompetent patients. Randomized clinical trials of liposomal amphotericin B in the treatment and secondary prophylaxis of HIV-VL coinfected patients is urgently needed to optimize treatment in this subset. With the availability of Liposomal amphotericin B at a preferential pricing in the endemic areas, short course combination therapy can become a viable alternative.
Drug resistance in leishmaniasis
Chakravarty Jaya,Sundar Shyam
Journal of Global Infectious Diseases , 2010,
Abstract: The treatment options of leishmaniasis are limited and far from satisfactory. For more than 60 years, treatment of leishmaniasis has centered around pentavalent antimonials (Sb v ). Widespread misuse has led to the emergence of Sb v resistance in the hyperendemic areas of North Bihar. Other antileishmanials could also face the same fate, especially in the anthroponotic cycle. The HIV/ visceral leishmaniasis (VL) coinfected patients are another potential source for the emergence of drug resistance. At present no molecular markers of resistance are available and the only reliable method for monitoring resistance of isolates is the technically demanding in vitro amastigote-macrophage model. As the armametrium of drugs for leishmaniasis is limited, it is important that effective monitoring of drug use and response should be done to prevent the spread of resistance. Regimens of simultaneous or sequential combinations should be seriously considered to limit the emergence of resistance.
BV regularity near the interface for nonuniform convex discontinuous flux
Shyam Sundar Ghoshal
Mathematics , 2015,
Abstract: In this paper, we discuss the total variation bound for the solution of scalar conservation laws with discontinuous flux. We prove the smoothing effect of the equation forcing the $BV_{loc}$ solution near the interface for $L^\infty$ initial data without the assumption on the uniform convexity of the fluxes made as in [1,21]. The proof relies on the method of characteristics and the explicit formulas.
Biopolymeric nanoparticles
Sushmitha Sundar, Joydip Kundu and Subhas C Kundu
Science and Technology of Advanced Materials , 2010,
Abstract: This review on nanoparticles highlights the various biopolymers (proteins and polysaccharides) which have recently revolutionized the world of biocompatible and degradable natural biological materials. The methods of their fabrication, including emulsification, desolvation, coacervation and electrospray drying are described. The characterization of different parameters for a given nanoparticle, such as particle size, surface charge, morphology, stability, structure, cellular uptake, cytotoxicity, drug loading and drug release, is outlined together with the relevant measurement techniques. Applications in the fields of medicine and biotechnology are discussed along with a promising future scope.
Disease survey of Safed Musli (Chlorophytum borivilianum) in zone IVa and V of Rajasthan
Indian Phytopathology , 2011,
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