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61.
Pavan S. Kulkarni Sachin D. Ghude S. L. Jain B. C. Arya P. K. Dubey Shahnawaz 《International journal of remote sensing》2013,34(6):1545-1559
A tropospheric ozone variability study is carried out to investigate the spatial and temporal distribution over the coastline of the Indian peninsula and adjacent land and sea using NASA Langley Tropospheric Ozone Residual data set for the period 1979–2005. A strong seasonal cycle has been observed with large variation (~ 55%) over the upper eastern coast, followed by the upper and lower western coast, compared to the lower eastern coast (~ 33%). A negative gradient in ozone concentration is observed along eastern and western coasts during summer (slope ~ –0.78 and –0.65) and a positive gradient (slope ~ 0.16 and 0.21) during winter. The same is observed over the adjacent land and sea along the coastline with slight variation. This change in gradient can be attributed to the anthropogenic emission of precursor gases that reinforce localized photochemical production of ozone. In addition, topography, transport, seasonality of emission of precursor gases and the solar insolation cycle play a vital role. 相似文献
62.
Y. Kalyana Lakshmi N. Pavan Kumar P. Venugopal Reddy 《Journal of Superconductivity and Novel Magnetism》2013,26(9):2975-2980
The effects of silver doping on the magnetotransport and thermopower of La1?x Ag x MnO3 (0.05≤x≤0.30) have been investigated. For the sample with x=0.05, temperature dependent resistivity exhibits an insulating behavior, while thermopower is found to be large and negative over the measured temperature range. An increase in the Ag doping enhances the conductivity and shifts the metal-insulator transition temperature toward high temperature side. The low temperature thermopower data has been explained in terms of diffusion, magnon drag, and phonon drag effects and found that the magnon drag effect dominates in this region. Finally, the electrical transport in the high temperature region has been analyzed by using adiabatic small polaron hopping mechanism. 相似文献
63.
M. Pedretti O. Cremonesi L. Foggetta A. Giachero A. Giuliani P. Gorla C. Nones M. Pavan C. Salvioni S. Sangiorgio 《Journal of Low Temperature Physics》2008,151(3-4):841-847
The main problem for experiments using the bolometric technique to search for rare events is the contribution of surface contamination
to the background. In this paper a new technique for the identification of the origin of events will be described. The idea
is to shield the main bolometer with bolometric shields. Tests on small and large prototypes and the promising results will
be reported.
相似文献
64.
R. Karthikeyan S. Balaji N. K. Chandrababu P. K. Sehgal 《Clean Technologies and Environmental Policy》2008,10(3):295-301
Acid hydrolysis of horn meal (obtained from raw horns of slaughtered cattle and buffaloes) yields a mixture of water soluble
and low molecular weight peptides with average particle size of 3,838 nm (3.84 μm) and mean intensity of 5,243.7 nm (5.24 μm)
and mean volume of 6,228.1 nm (6.23 μm). These peptides on reaction with Cr(III) yield a product that exhibits high exhaustion
of chromium bath (above 92%) during tanning of hides and skins. To consolidate the results, the process was up-scaled in Central
Leather Research Institute (CLRI) pilot plant for commercial trials. This material is applied directly to the pickled pelts
at 8% w/w level and then the pelt is converted to wet blues and crust leathers. Control leathers were also processed concurrently
using standard chrome tanning salts (8% w/w). Leathers showed the desired level of softness, fullness, shrinkage temperature
and physical properties, and are comparable with control ones. Our results have indicated the use of Cr(III)–keratin complex
could considerably reduce pollution load of Cr salts in leather processing. 相似文献
65.
Quasi-single-phase mathematical models as applied to the ladle hydrodynamics have been analysed rigorously. It is shown that choice of convergence criteria, nodal configuration and differencing schemes all influence the computed results significantly and consequently, results independent of these numerical parameters must first be established to draw any useful conclusion. Several quasi-single-phase computational procedures reported in the literature to study the gas-injection-induced flow phenomena have been critically examined. To this end, experimentally measured bulk flow-fields, plume-rise velocity and gas voidages have been compared with those predicted numerically. Such comparisons indicate that the bottom injection phenomena (viz., bulk flow, plume-rise velocity, and gas volume fraction within the plume etc.) can be adequately represented by assuming bubble slippage and considering a constant rise velocity in the two-phase region in the numerical solution scheme. 相似文献
66.
Shanthi Pavan 《IEEE transactions on circuits and systems. I, Regular papers》2008,55(6):1412-1420
67.
Francesco Fatone Paolo Battistoni David Bolzonella Paolo Pavan Franco Cecchia 《Desalination》2008,227(1-3):72
The alternating processes applied in membrane bioreactors for municipal wastewater treatment may be an attractive option to reduce the energy consumptions and optimize carbon and nitrogen removal. However, the knowledge of these systems is often based on empirical results so to discourage the plant operators for its adoption. This paper discusses and compares the empirical evidence coming from two different alternating membrane bioreactors, a demonstration and a full-scale one. The two plants treat two real municipal wastewaters, rather different for both C:N ratio and degree of biodegradability of the influent organics. Nine steady-state runs have been carried out in the demonstration plant, while a one whole year operation has been considered for the full-scale system. Combining the results of the two MBRs, it was found that the alternating process was able to adjust automatically and adequately the aeration of the biological reactor with a nitrogen loading rate in the range 0.05–0.18 kgN m−3 d−1 and C:N mass ratios greater than 5–6. As a result, the use of the available carbon source, with concern to the total nitrogen removal, was as low as 0.1 kg of total nitrogen removed per kg of total influent COD. Effluent total nitrogen met the standard for reuse with specific energy consumptions in the range 85–109 gTNremoved per kWhconsumed. Considering the usual loading conditions of the municipal wastewater treatment plants in Italy, membrane bioreactors operating alternating processes may be implemented to increase the nitrogen treatment capacity of existing plants and achieve the standards for reuse. 相似文献
68.
69.
This study mainly deals with cenosphere‐filled phenolic resin‐based composite that is prepared using ceramic‐ceramic fiber as reinforcement by traditional hand layup technique. The effect of cenosphere at various percentage is investigated on the mechanical, ablative, and thermal properties of the filled composites. Mechanical investigation revealed that the addition of microsized cenosphere up to 10% concentration increased the tensile strength of the composite. It is also observed that the addition of cenosphere increased the compressive strength and impact resistance of the composites. Thermogravimetric analysis (TGA) and ablative test revealed that the addition of cenosphere not only decreased both linear and mass ablative rates but also increased the upper working temperature of the filled ceramic/phenolic composites. POLYM. COMPOS., 37:1906–1913, 2016. © 2015 Society of Plastics Engineers 相似文献
70.
Ying Zhang Surya K. Mallapragada Balaji Narasimhan 《Polymer Engineering and Science》2010,50(5):863-870
The dissolution behavior of polystyrene (PS) and low‐density polyethylene (LDPE) in biodiesel was investigated with an eye towards developing methods to dispose waste plastics by burning them with fuel. To complement and guide the experimental investigations, molecular dynamics simulations were performed to calculate solubility parameters, cohesive energy densities, Flory‐Huggins χ parameters and phase diagrams of the target systems. Dissolution kinetics of PS and LDPE in methyl esters was monitored by gravimetry, from which parameters such as dissolution rates, activation energies, and scaling indices were estimated. The shear viscosity of the polymer solutions was measured to ascertain their suitability as fuel mixtures. The dissolution of PS in biodiesel appears to be controlled by the diffusion of polymer chains through a boundary layer adjacent to the polymer/solvent interface. Taken together, the experimental and modeling studies provide a predictive toolbox to design biodiesels of different compositions that will dissolve commodity polymers such as PS and LDPE to be used as fuels in engines. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers 相似文献