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991.
Amit Kumar Maity Kalipada Maity Shyamal Kumar Mondal Manoranjan Maiti 《Optimization and Engineering》2009,10(3):427-438
This paper develops an integrated production-recycling system over a finite time horizon. Here, the dynamic demand is satisfied
by production and recycling. The used units are bought back and then either recycled or disposed of which are not repairable.
The used units are collected continuously from the customers. Recycling products can be used as new products which are sold
again. The rate of production and disposal are assumed to be function of time. The setup cost is reduced over time due to
“Learning curve” effect. The optimum results are presented both in tabular form and graphically. 相似文献
992.
993.
Abstract We introduce the inverse of the Hermitian operator (ââ ?) and express the Boson inverse operators â ?1 and â ??1 in terms of the operators â, â ? and (ââ ?)?1. We show that these Boson inverse operators may be realized by Susskind-Glogower phase operators. In this way, we find a new two-photon annihilation operator and denote it as â 2(ââ ?)?1. We show that the eigenstates of this operator have interesting non-classical properties. We find that the eigenstates of the operators (ââ ?)?1 â 2, â(ââ ?)?1 â and â 2(ââ ?)?1 have many similar properties and thus they constitute a family of two-photon annihilation operators. 相似文献
994.
A Al-Othman S Al-Musharaf NM Al-Daghri S Yakout KM Alkharfy Y Al-Saleh OS Al-Attas MS Alokail O Moharram S Sabico S Kumar GP Chrousos 《Nutrition journal》2012,11(1):56
ABSTRACT: BACKGROUND: Coffee and tea consumption was hypothesized to interact with variants of vitamin D-receptor polymorphisms, but limited evidence exists. Here we determine for the first time whether increased coffee and tea consumption affects circulating levels of 25-hydroxyvitamin D in a cohort of Saudi adolescents. METHODS: A total of 330 randomly selected Saudi adolescents were included. Anthropometrics were recorded and fasting blood samples were analyzed for routine analysis of fasting glucose, lipid levels, calcium, albumin and phosphorous. Frequency of coffee and tea intake was noted. 25-hydroxyvitamin D levels were measured using enzyme-linked immunosorbent assays. RESULTS: Improved lipid profiles were observed in both boys and girls, as demonstrated by increased levels of HDL-cholesterol, even after controlling for age and BMI, among those consuming 9--12 cups of coffee/week. Vitamin D levels were significantly highest among those consuming 9--12 cups of tea/week in all subjects (p-value 0.009) independent of age, gender, BMI, physical activity and sun exposure. CONCLUSION: This study suggests a link between tea consumption and vitamin D levels in a cohort of Saudi adolescents, independent of age, BMI, gender, physical activity and sun exposure. These findings should be confirmed prospectively. 相似文献
995.
A.M.P. Sakita E.C. Passamani H. Kumar D.R. Cornejo C.S. Fugivara R.D. Noce A.V. Benedetti 《Materials Chemistry and Physics》2013
The influence of current density, at the interval 5–100 mA cm−2, on the structural and magnetic properties of electrodeposited (Co100−xNix)100−yWy alloys (x = 23–33.5 at. % Ni, y = 1.7–7.3 at. % W) was studied from a glycine-containing bath. W-content decreases with the increase of the current density magnitude. X-ray data have shown stabilization of hexagonal close packed, face centered cubic or a mixture of these structures by modulating the applied cathodic current density, for values lower than 50 mA cm−2. Two structural phase transitions were observed: one from hexagonal close packed to face centered cubic structural transition occurring for a current density of 20 mA cm−2, and another one, from cubic crystalline phase to amorphous state, which happens for values higher than 50 mA cm−2. These structural phase transitions seem to be associated with the W-content as well as average crystalline grain sizes that reduce with increasing the current density value. The grain size effect may explain the face centered cubic stabilization in Co-rich CoNiW alloys, which was initially assumed to be basically due to H-adsorption/incorporation. Magnetic properties of Co-rich CoNiW alloys are strongly modified by the current density value; as a result of the changes on the W-content and their structural properties. 相似文献
996.
Santhakumar Kannappan Kumar Palanisamy Jiro Tatsugi Paik-Kyun Shin Shizuyasu Ochiai 《Journal of Materials Science》2013,48(6):2308-2317
Organic solar cells have been significantly attracted due to the need to develop an inexpensive clean and sustainable renewable energy source. We report on the fabrication of poly [N-9″-hepta-decanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)]/[6, 6]-phenyl-C71-butyric acid methyl ester blend active layer using airbrush spray-coating method in mixed solvents. Optical absorption of the active layers was analyzed using UV–visible spectral studies in the wavelength range from 300 to 800 nm. The surface morphology of the active layers deposited with different parameters (spraying time and substrate-nozzle distance) was examined using atomic force microscopy. The current density–voltage (J–V) characteristics of photovoltaic cells were measured under the illumination of simulated solar light with 100 mW cm?2 (AM 1.5G) by an Oriel 1000 W solar simulator. The power conversion efficiency of the solar cell is more than 5 %. 相似文献
997.
Susanta Kumar Gauri Surajit Pal 《The International Journal of Advanced Manufacturing Technology》2010,48(9-12):1205-1220
The Taguchi method of experimental design is widely used for optimization of process performance. However, this method has been developed to optimize single-response processes. But, in many situations, the engineers are required to determine the process settings that can simultaneously optimize multiple responses. In the recent past, researchers have proposed several systematic procedures for multi-response optimization. Most of these methods use complicated statistical/mathematical models and are, therefore, not easily comprehendible to the engineers who do not have a strong background in mathematics. Only a few methods, e.g. weighted signal-to-noise (WSN) ratio, Grey relational analysis, multiple-response signal-to-noise ratio, VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje in Serbian), and weighted principal component methods, use relatively simpler procedures. In this paper, the computational procedures for these five methods are standardized. Three sets of experimental data are analyzed using these standardized procedures and the predicted optimization performances of the five methods are compared. The results show that no method can give better optimization than the WSN method. 相似文献
998.
Jidong Kang David S. Wilkinson Raja K. Mishra J. David Embury Elhachmi Essadiqi Amjad Javaid 《Journal of Materials Engineering and Performance》2013,22(5):1386-1395
There are considerable data in the literature dealing with deformation mechanisms in AZ31 sheets. However, there is little information on the damage and fracture processes in this material. In this contribution, digital image correlation is used to follow deformation patterns occurring during tensile and v-bending tests at room temperature. A variety of surface analysis techniques and three-dimensional x-ray tomography have been used to examine the relationship between deformation, damage initiation, and the final fracture processes. The results show that premature diffuse necking occurs in the tensile tests without transit into localized necking. Deformation twins cluster by an autocatalytic process to form shear bands serving as preferential sites for strain localization and crack initiation. Damage appears in the form of microcracks within the shear bands at a late stage of necking and lead to the final fracture. The presence and the distribution of second-phase particles and their distributions help accelerate the final fracture processes. 相似文献
999.
S. Manoj Kumar N. Rajkumar W. Catherine Christinal Mary 《Wireless Personal Communications》2013,70(4):1697-1709
In Wireless Sensor Network (WSN) sensors are densely deployed where the intruders can compromise some sensor nodes and inject false data in order to raise false alarms, reduce network lifetime, utilize bandwidth resources and so on. False Data Injection can possibly occur in Data Aggregation (DA) and Data Forwarding (DF). This paper analyses EFDD Protocol-Early False Data Detection Protocol which addresses the two possibilities in a simple and secure way considering the constraints of sensor nodes. The main idea is the selection of the network structure; this protocol will work effectively in Spatial/Semantic Correlation Tree Structure (SCT). False Data Detection in DA is done using some monitoring nodes which will monitor the Data Aggregator. EFDD in SCT structure reduce the counterfeit data transmission when compared to other structure in a better way. The result shows that EFDD reduce data transmission by dropping false data earlier and it also reduces computation when compared to the existing schemes. 相似文献
1000.
Ismail Rahath Kubra Devender Kumar Lingamallu Jagan Mohan Rao 《International Journal of Food Science & Technology》2013,48(9):1828-1833
The significance of different variables viz. temperature, time and solvent at constant power in microwave‐assisted extraction (MAE) process of ginger was studied and compared with conventional method. Aqueous ethanol (50%) provided higher yields of extract as well as the highest release of total polyphenols (TPP) than alcoholic solvents. The reason could be the high dielectric constant of aqueous ethanol as compared to alcohols. Microwave heating being a volumetric process, an exposure time of 1 min was found to be sufficient. The better penetration of microwaves and greater solubility at higher temperature resulted in higher yield of TPP and [6]‐gingerol. The resultant extract showed higher radical scavenging activity (RSA) values. Thus, MAE allowed higher recoveries compared to conventional extraction process, with improvement in the quantity and quality of extract in very short period of time. 相似文献