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91.
V.?S.?S.?YadavalliEmail author Diatha?Krishna?Sundar Swaminathan?Udayabaskaran 《Annals of Operations Research》2015,235(1):517-542
A disaster inventory system is considered in which two substitutable items are stored for disaster management. In the event of disaster management, a particular product may become stock-out and the situation warrants that a demand for the particular product during its stock-out period may be substituted with another available similar product in the inventory. From the utility point of view, continuous review inventory models are quite appropriate in disaster inventory management. In this paper, a continuous review two substitutable perishable product disaster inventory model is proposed and analyzed. Since the inventory is maintained for disaster management, an adjustable joint reordering policy for replenishment is adopted. There is no lead time and the replenishment is instantaneous. For this model, some measures of system performance are obtained. The stationary behavior of the model is also considered. Numerical examples are also provided to illustrate the results obtained. 相似文献
92.
K. Jeyadheepan P. Palanichamy V. Swaminathan M. Jayachandran C. Sanjeeviraja 《Applied Physics A: Materials Science & Processing》2010,98(4):919-925
Cadmium stannate (Cd2SnO4) thin films were prepared by the RF magnetron sputtering technique on glass substrates with substrate temperatures of room
temperature (RT), 100°C, 200°C and 300°C. Photoacoustic analyses were made to obtain the thermal diffusivity and the optical
bandgap values of the Cd2SnO4 thin films. The change in thermal diffusivity of the films with the substrate temperature was analyzed. The optical bandgap
values obtained from the photoacoustic spectroscopy were compared with the values obtained from the optical transmittance
spectra. X-ray photoelectron spectroscopic (XPS) studies confirm the formation of stoichiometric films. Surface morphological
studies by atomic force microscopy (AFM) revealed the crystalline nature of the films deposited at 100°C. 相似文献
93.
Lactic acid fermentation in cell-recycle membrane bioreactor 总被引:2,自引:0,他引:2
Traditional lactic acid fermentation suffers from low productivity and low product purity. Cell-recycle fermentation has become
one of the methods to obtain high cell density, which results in higher productivity. Lactic acid fermentation was investigated
in a cell-recycle membrane bioreactor at higher substrate concentrations of 100 and 120 g/dm3. A maximum cell density of 145 g/dm3 and a maximum productivity of 34 g/(dm3…h) were achieved in cell-recycle fermentation. In spite of complete consumption of substrate, there was a continuous increase
in cell density in cell-recycle fermentation. Control of cell density in cell-recycle fermentation was attempted by cell bleeding
and reduction in yeast extract concentration. 相似文献
94.
Jegadesan S Sindhu S Advincula RC Valiyaveettil S 《Langmuir : the ACS journal of surfaces and colloids》2006,22(2):780-786
The direct nanopatterning of polycarbazole on ultrathin films of a "precursor polymer" and monomer under ambient conditions is reported. In contrast to previous reports on electrochemical dip-pen nanolithography using monomer ink or electrolyte-saturated films in electrostatic nanolithography, these features were directly patterned on spin-cast films of carbazole monomer and poly(vinylcarbazole) (PVK) under room temperature and humidity conditions. Using a voltage-biased atomic force microscope (AFM) tip, electric-field-induced polymerization and cross-linking occurred with nanopatterning in these films. Different parameters, including writing speed and bias voltages, were studied to demonstrate line width and patterning geometry control. The conducting property (current-voltage (I-V) curves) of these nanopatterns was also investigated using a conducting-AFM (C-AFM) setup, and the thermal stability of the patterns was evaluated by annealing the polymer/monomer film above the glass transition (T(g)) temperature of the precursor polymer. To the best of our knowledge, this is the first report in which thermally stable conducting nanopatterns were drawn directly on monomer or polymer film substrates using an electrochemical nanolithography technique under ambient conditions. 相似文献
95.
Varghese B Cheong FC Sindhu S Yu T Lim CT Valiyaveettil S Sow CH 《Langmuir : the ACS journal of surfaces and colloids》2006,22(19):8248-8252
We report a simple and effective approach to organize micron- and submicron-sized particles in a size selective manner. This approach utilizes the template assisted directed self-assembly technique. A topographically patterned photoresist surface is fabricated and used to create an ordered array of colloidal particles from their aqueous suspensions. Assembly of particles on this template is then achieved by using a conventional spin coating technique. Feasibility of this technique to form a large area of patterned particle assemblies has been investigated. To arrange the particles on the template, the physical confinement offered by the surface topography must overcome a joint effect of centrifugal force and the hydrophobic nature of the photoresist surface. This concept has been extended to the size selective sorting of colloidal particles. The capability of this technique for sorting and organizing colloidal particles of a particular diameter from a mixture of microspheres is demonstrated. 相似文献
96.
Managing new and differentiated remanufactured products 总被引:2,自引:0,他引:2
We study a firm that makes new products in the first period and uses returned cores to make remanufactured products (along with new products) in future periods. The remanufactured product is differentiated from the new product, so the firm needs to choose differentiated prices. We analyze the monopoly environment in two-period, multi-period (three, four and five) and infinite planning horizons, and characterize the optimal remanufacturing and pricing strategy for the firm. In the process, we identify remanufacturing savings thresholds that determine the production and pricing strategy for the firm. Among other results, we find—counter to intuition—that in a finite-horizon, multi-period setting, the optimal policy is not necessarily monotone in remanufacturing savings. 相似文献
97.
98.
V.Srirama Swaminathan B.H. Suits 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1998,132(2):274-278
Theoretical and experimental results for NMR imaging measurements of powdered materials using the + to − transition of -integerspin nuclei in the presence of a very large second-order electric quadrupolar broadening are presented. An “effective spin-” formalism is developed to account for additional effects due to the presence of quadrupolar interactions comparable in size to the Zeeman interaction. A large (7.9 mT/cm-A, with a maximum current of ≈20 A), rapid (≈30 μs) pulsed linear gradient field is used with echoes and phase encoding techniques to obtain images in the limit γH1is much narrower than the NMR linewidth. A one-dimensional projection of the second-order quadrupolar perturbed, 4-MHz-wide, + ↔ − transition for63Cu in Cu2O powder is presented as an example. An experimental one-dimensional projection of a sample containing Cu2O and YBa2Cu3O6.7is also presented. 相似文献
99.
The carbinol is found to rearrange to the bicyclo (2,2,2) octane derivative in the presence of base; the rearrangement involves a transannular reaction in a ten membered ring resulting from an Oxy-Cope system. 相似文献
100.
B. Saha K. Swaminathan C. R. Venkatasubramani P. R. Vasudeva Rao 《Journal of Radioanalytical and Nuclear Chemistry》1996,214(1):17-27
The extraction of Ce (IV) by di-(2-ethylhexyl)-phosphoric acid (HDEHP) has been studied as a function of nitric acid concentration. Using the distribution coefficient data, the optimum conditions for recovery of Ce (IV) from nitric acid medium were arrived at. Under the conditions employed for Ce(IV), a small percentage of Ru was also found to be extracted. Cerium could be selectively stripped from the organic phase with 8M HNO3/30% H2O2 solution. This procedure led to the recovery of144Ce free of106Ru. Based on the solvent extraction data, an extraction-chromatographic procedure employing HDEHP (40% w/w) loaded on Amberlite XAD-7 as the stationary phase was developed for the isolation of pure, carrier-free144Ce from the spent fuel solution. 相似文献