NOPR Collection:

Global telecom revolution: Spatial - Temporal aspects

2016-07-20T04:12:25Z

Title: Global telecom revolution: Spatial - Temporal aspects Authors: Nauriyal, D K; Bhalla, Sanjeev Abstract: Current global telecommunication landscape is undergoing a paradigm change in terms of technologies and usage. Global System for Mobile (GSM) communications has emerged as the preferred technology followed by the fast growing Code Division Multiple Access (COMA) technology. Developed countries (without the transition countries) lead the world in number of landline and cellular connections, followed by high-income developing countries, which show the maximum growth. Paper also presents an analysis based on Digital Access Index (DAI) of the countries. India has emerged as a noteworthy participant in telecommunication market. Paper discusses techno-commercial and regulatory mechanism prevalent in the country. Page(s): 195-212

Leachate removal rate and the effect of leachate on the hydraulic conductivity of natural (undisturbed) clay

2009-06-26T16:31:17Z

Title: Leachate removal rate and the effect of leachate on the hydraulic conductivity of natural (undisturbed) clay Authors: Ozcoban, M S; Tufekci, N; Tutus, S; Sahin, U; Celik, S O Abstract: Hydraulic conductivity (HC) is perhaps the most important unique parameter determined in the laboratory for predicting mobility of leachates through clay liners. Typically, HC must be < or = 1x10^-9 m/s for soil liners and covers used to contain hazardous waste, industrial waste, and municipal solid waste (MSW). Soil samples used in this study were obtained from the Kemerburgaz landfill in Istanbul. The study presents change in clay HC brought about by the chemical reactions between clay and a permeant. Any change induced by such a reaction in the microstructure (microfabric) of the clay was studied by scanning electron microscope. In order to determine the removal capability of the natural clay, COD, SS, VSS, Total P, TKN, Cu, Mn, Fe are also measured in the influent and effluent of the lab-scale reactor. Page(s): 264-269

Removal of indigocarmine from industrial effluents using low cost adsorbent

2009-06-27T16:30:56Z

Title: Removal of indigocarmine from industrial effluents using low cost adsorbent Authors: Jain, Rajeev; Mathur, Megha; Sikarwar, Shalini Abstract: In the present paper, adsorption technique was employed for removal of indigocarmine and the technique was found to be very useful and cost effective for a better removal of dye. The operating variables such as adsorbent dose, adsorbate concentration, particle size, pH, contact time and temperature were optimized. Page(s): 258-263

Benzene and toluene profiles in ambient air of Delhi as determined by active sampling and GC analysis

2009-06-26T16:31:30Z

Title: Benzene and toluene profiles in ambient air of Delhi as determined by active sampling and GC analysis Authors: Kumar, Anuj; Tyagi, S K Abstract: Present study aims to standardise methodology for the measurement of benzene and toluene using active sampling onto sorbent tubes and to investigate their existing profile in the urban environment of Delhi, India. Samples were collected by active sampling onto preconditioned stainless steel standard adsorbent tubes packed with Tenax TA adsorbent using a portable constant low flow volume sampler. Sampling flow rate ranged 20-25 ml min^-1 and sampling duration 1.30-2.30 h. Samples were analysed by thermal desorption followed by gas chromatography coupled with automated thermal desorber. The desorption system was provided with a cryogenic trap filled with Tenax TA adsorbent. External calibration was performed using five concentration levels of standards solutions in carbon disulfide (CS₂). Linear fit in all cases were found good with R² > 0.99. Benzene concentration ranged 33.69-174.62 µg m^-3 whereas toluene ranged 45.18-228.83µg m^-3 in the vicinity of petrol pump along with heavy traffic roadside at Preet Vihar location. Average benzene and toluene concentration of ambient air at ITO (near a busy traffic intersection) ranged 13.03-33.06 µg m^-3 and 19.71-57.64 µg m^-3 respectively. While at East Arjun Nagar (a residential cum institutional area), levels were 17.69 µg m^-3 and 22.81 µg m^-3 for benzene and toluene, respectively. Present study indicated that the concentration of benzene at all the sites was higher than the limit values prescribed in the UK (16 µg m^-3, running annual average) and European Commission (5 µg m^-3, annual average). Average toluene and benzene ratio ranged between 1.29 µg m^-3 in residential cum institutional area to 1.74 µg m^-3 at busy traffic intersection. Page(s): 252-257