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61.
Ashish Kumar Jindal Lawrence Overzet Matthew Goeckner 《Plasma Chemistry and Plasma Processing》2010,30(2):287-297
Pulsed plasmas containing organic precursors are becoming increasingly common for multiple applications. To understand the
nature of such discharges, in-situ time resolved microwave interferometry measurements of the electron density in a 60 W pulsed
inductively coupled 1,3-butadiene discharge have been made. Measurements were also made for continuous wave plasmas at 40,
50, 60 and 70 W power for comparison. The data shows that the time averaged electron densities are independent of pulse width
at a particular duty cycle. In addition, time averaged values increase approximately linearly with increasing duty cycle.
Such linearity in average density is tied to the ambipolar loss rate. This knowledge is important for understanding the growth
kinetics of plasma polymerized films. 相似文献
62.
Chlorella minutissima—A Promising Fuel Alga for Cultivation in Municipal Wastewaters 总被引:1,自引:0,他引:1
Ashish Bhatnagar Monica Bhatnagar Senthil Chinnasamy K. C. Das 《Applied biochemistry and biotechnology》2010,161(1-8):523-536
It is imperative to slash the cost of algal oil to less than $50 bbl?1 for successful algal biofuel production. Use of municipal wastewater for algal cultivation could obviate the need for freshwater and the nutrients—N and P. It would also add CO2 through bacterial activity. Chlorella minutissima Fott et Nova dominated the entire phycoflora year around and through each stage of the wastewater treatment at the oxidation pond system of Wazirabad (Delhi) in India. The ability to grow so profusely in such varied and contrasting situations made this alga unique. Besides pollution tolerance, it grew heterotrophically in dark under acidic conditions and as a mixotroph in presence of light over a range of organic C substrates. It could utilize both ammoniacal and nitrate nitrogen, survived anaerobicity, 5% NaCl and ?10 bar of osmotic stress. C. minutissima grew at pH 4–11 and raised the pH set initially by 1 to 3 units in 7.5 h. It showed gigantism and largely kept afloat in presence of utilizable organic carbon, while flocculated in mineral medium and on aging. The alga also possessed potential for biofuel production. The studied parameters indicate why C. minutissima was a potential biomass builder in municipal sewage and could be used to determine which other alga(e) may serve the purpose. 相似文献
63.
ZnS:Cu nanophosphors were prepared by wet chemical methods and characterized by X-ray diffraction (XRD). The typical morphologies of the nanophosphors were investigated by scanning electron microscopy (SEM). The thermoluminescence (TL) properties of inorganically and organically passivated ZnS:Cu nanophosphors were investigated after γ-irradiation using a 60Co source at room temperature. The TL glow curve of capped ZnS:Cu showed variation in TL peak and intensity as the capping agent was changed. Amongst the synthesized samples the TL glow curve of SiO2 capped ZnS:Cu showed the highest TL intensity. It has been found that TL response of SiO2 capped ZnS:Cu is linear in the range 10-550 Gy. A discussion of the obtained results is also presented. 相似文献
64.
Use of ultrasound can yield polymer degradation as reflected by a significant reduction in the intrinsic viscosity or the molecular weight. The ultrasonic degradation of two water soluble polymers viz. carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) has been studied in the present work. The effect of different operating parameters such as time of irradiation, immersion depth of horn and solution concentration has been investigated initially using laboratory scale operation followed by intensification studies using different additives such as air, sodium chloride and surfactant. Effect of scale of operation has been investigated with experiments in the available different capacity reactors with an objective of recommending a suitable type of configuration for large scale operation. The experimental results show that the viscosity of polymer solution decreased with an increase in the ultrasonic irradiation time and approached a limiting value. Use of additives such as air, sodium chloride and surfactant helps in increasing the extent of viscosity reduction. At higher frequency operation the viscosity reduction has been found to be negligible possibly attributed to less contribution of the physical effects. The viscosity reduction in the case of ultrasonic horn has been observed to be more as compared to other large capacity reactors. Kinetic analysis of the polymer degradation process has also been performed. The present work has enabled us to understand the role of the different operating parameters in deciding the extent of viscosity reduction in polymer systems and also the controlling effects of low frequency high power ultrasound with experiments on different scales of operation. 相似文献
65.
Shashaank Gupta Shuvrajyoti Bhattacharjee Dhananjai Pandey Vipul Bansal Suresh K. Bhargava Ju Lin Peng Ashish Garg 《Applied Physics A: Materials Science & Processing》2011,104(1):395-400
We report an unusual behavior observed in (BiFeO3)1−x
–(PbTiO3)
x
(BF–xPT) thin films prepared using a multilayer chemical solution deposition method. Films of different compositions were grown
by depositing several bilayers of BF and PT precursors of varying BF and PT layer thicknesses followed by heat treatment in
air. X-ray diffraction showed that samples of all compositions show mixing of two compounds resulting in a single-phase mixture,
also confirmed by transmission electron microscopy. In contrast to bulk compositions, samples show a monoclinic (MA-type) structure suggesting disappearance of the morphotropic phase boundary (MPB) at x=0.30 as observed in the bulk. This is accompanied by the lack of any enhancement of the remanent polarization at the MPB,
as shown by the ferroelectric measurements. Magnetic measurements showed an increase in the magnetization of the samples with
increasing BF content. Significant magnetization in the samples indicates melting of spin spirals in the BF–xPT films, arising from a random distribution of iron atoms. Absence of Fe2+ ions was corroborated by X-ray photoelectron spectroscopy measurements. The results illustrate that thin film processing
methodology significantly changes the structural evolution, in contrast to predictions from the equilibrium phase diagram,
besides modifying the functional characteristics of the BP-xPT system dramatically. 相似文献
66.
Jiang Wu Liang-Yuh Ouyang Leopoldo Eduardo Cárdenas-Barrón Suresh Kumar Goyal 《European Journal of Operational Research》2014
In a supplier-retailer-buyer supply chain, the supplier frequently offers the retailer a trade credit of S periods, and the retailer in turn provides a trade credit of R periods to her/his buyer to stimulate sales and reduce inventory. From the seller’s perspective, granting trade credit increases sales and revenue but also increases opportunity cost (i.e., the capital opportunity loss during credit period) and default risk (i.e., the percentage that the buyer will not be able to pay off her/his debt obligations). Hence, how to determine credit period is increasingly recognized as an important strategy to increase seller’s profitability. Also, many products such as fruits, vegetables, high-tech products, pharmaceuticals, and volatile liquids not only deteriorate continuously due to evaporation, obsolescence and spoilage but also have their expiration dates. However, only a few researchers take the expiration date of a deteriorating item into consideration. This paper proposes an economic order quantity model for the retailer where: (a) the supplier provides an up-stream trade credit and the retailer also offers a down-stream trade credit, (b) the retailer’s down-stream trade credit to the buyer not only increases sales and revenue but also opportunity cost and default risk, and (c) deteriorating items not only deteriorate continuously but also have their expiration dates. We then show that the retailer’s optimal credit period and cycle time not only exist but also are unique. Furthermore, we discuss several special cases including for non-deteriorating items. Finally, we run some numerical examples to illustrate the problem and provide managerial insights. 相似文献
67.
In the present paper, we consider Mond-Weir type nondifferentiable second order fractional symmetric dual programs over arbitrary cones and derive duality results under second order K?F-convexity/K?F-pseudoconvexity assumptions. Our results generalize several known results in the literature. 相似文献
68.
A comprehensive note on: An inventory model under two levels of trade credit and limited storage space derived without derivatives 总被引:1,自引:0,他引:1
In 2006, Huang proposed an inventory model with two warehouses when the supplier offers the retailer a permissible delay of M periods, and the retailer also provides its customers a permissible delay of N periods. He then solved it without derivatives. In this note, we extend his model to complement the shortcomings of his model. In contrast to the complicated and tedious quadratic–algebraic method suggested by Huang, we propose a simple arithmetic–geometric method to solve the inventory problem. Finally, we run computer programs for several numerical examples to illustrate the proposed model and obtain some managerial implications. 相似文献
69.
70.
J Santhanalakshmi G Shantha Lakshmi V K Aswal P S Goyal 《Journal of Chemical Sciences》2001,113(1):55-62
Small angle neutron scattering (SANS) measurements of D2O solutions (0.1 M) of sodium cholate (NaC) and sodium deoxycholate (NaDC) were carried out atT= 298 K. Under compositions very much above the critical micelle concentration (CMC), the bile salt micelle size growths were
monitored by adopting Hayter-Penfold type analysis of the scattering data. NaC and NaDC solutions show presence of correlation
peaks atQ = 0.12 and 0.1 ?-1 respectively. Monodisperse ellipsoids of the micelles produce best fits. For NaC and NaDC systems, aggregation number (9.0,
16.0), fraction of the free counterions per micelle (0.79, 0.62), semi-minor (8.0 ?) and semi-major axes (18.4, 31.7 ?) values
for the micelles were deduced. Extent of micellar growth was studied using ESR correlation time measurements on a suitable
probe incorporating NaC and NaDC micelles. The growth parameter (axial ratio) values were found to be 2.3 and 4.0 for NaC
and NaDC systems respectively. The values agree with those of SANS. 相似文献