Investigation of radiative interactions in supersonic internal flows

Analyses and numerical procedures are presented to study the radiative interactions of absorbing emitting species in chemically reacting supersonic flow in various ducts. The 2-D time dependent Navier-Stokes equations in conjunction with radiative flux equation are used to study supersonic flows undergoing finite rate chemical reaction in a hydrogen air system. The specific problem considered is the flow of premixed radiating gas between parallel plates. Specific attention was directed toward studying the radiative contribution of H2O, OH, and NO under realistic physical and flow conditions. Results are presented for the radiative flux obtained for different gases and for various combination of these gases. The problem of chemically reacting and radiating flows was solved for the flow of premixed hydrogen-air through a 10 deg compression ramp. Results demonstrate that the radiative interaction increases with an increase in pressure, temperature, amount of participating species, plate spacing, and Mach number. Most of the energy, however, is transferred by convection in the flow direction. In general the results indicate that radiation can have a significant effect on the entire flow field

AMMONIA GAS(NH3) SENSING OF SnO2-CuO MIXED OXIDE THICK FILM AT OPERATING TEMPERATURE

Objective To develop ammonia gas sensor by SnO2-CuO Mixed oxide thick film which is highly sensitive at particular optimum temperature.Materials and Methods:The SnO2 and CuO powder mixed with different ratio and heated at 8000C and then this powder is used to prepared thickfilms by a screen – printing technique on glass substrate.Results:The NH3 gas sensing properties, preferably the rate of response of CuO-SnO2 sensors are influenced by the CuO doping and operatingtemperature. XRD analysis showed that crystallite size is small (97.3nm) for 50SnO2-50CuO composition. Thermal analysis (TG/DTA) is the calculateof change in weight and energy in the form of heat as the material is being cooled or heated at a constant rate. The resistance change per ppm is foundto be 82 MΩ for SA5 sample.Conclusion : 50SnO2-50CuO composition sample is optimize for better sensing material as regards to other

Reverse supply chains: A source of opportunities and challenges

Reverse supply chains: A source of opportunities and challenges

A Goal Programming Approach to the Remanufacturing Supply Chain Model

Copyright 2001 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.The current trend of depletion of natural resources due to an ever-increasing number of consumer goods manufactured has led to an increase in the quantity of used and outdated products discarded. From an environmental point of view, it is not only desirable to disassemble, reuse, remanufacture and/or recycle the discarded products, in many cases it can also be economically justified. This situation being the motive, in recent years there have been several studies reported on disassembly, remanufacturing and/or recycling environments. Since “environmentally conscious manufacturing" is a relatively new concept that brings new costs and profits into consideration, its analysis cannot be provided by readily available techniques. This paper presents a quantitative methodology to determine the allowable tolerance limits of planned/unplanned inventory in a remanufacturing supply chain environment based on the decision-maker’s unique preferences. To this end, an integer goal-programming model that provides a unique solution for the allowable inventory level is presented. The objective of the supply-chain model is to determine the number of a variety of components to be kept in the inventory while economically fulfilling the demand of a multitude of components, and yet have an environmentally benign policy of minimizing waste generation.A numerical example is presented to illustrate the methodology.http://dx.doi.org/10.1117/12.41726

A Genetic Algorithm for Disassembly Process Planning

Copyright 2001 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.When a product reaches it’s end-of-life, there are several options available for processing it including reuse, remanufacturing, recycling, and disposing (the least desirable option). In almost all cases, a certain level of disassembly may be necessary. Thus, finding an optimal (or near optimal) disassembly sequence is crucial to increasing the efficiency of the process. Disassembly operations are labor intensive, can be costly, have unique characteristics and cannot be considered as reverse of assembly operations. Since the complexity of determining the best disassembly sequence increases with the increase in the number of parts of the product, it is extremely crucial that an efficient methodology for disassembly process planning be developed. In this paper, we present a genetic algorithm for disassembly process planning. A case example is considered to demonstrate the functionality of the algorithm.http://dx.doi.org/10.1117/12.45526

The influence of PMS and PDS oxidants on reaction rate of photocatalytic degradation of p-cresol over TiO2 powder - Advanced Oxidation Process

The degradation of p-cresol is approved out under UV-visible light by TiO2 as a photocatalyst. In the direction of determining the efficiency of the photocatalyst, the, unlike variables, studied built-in the amount of photocatalyst, consequence of oxidants peroxomonosulphate (PMS) and peroxodisulphate (PDS) on the photocatalytic oxidation of p-cresol on elucidation TiO2 surface have been investigating. The efficiencies of these oxidants on photocatalytic degradation of p-cresol are compared with that of PMS and PDS.The investigational results indicate that these oxidants reveal improved rates of mineralization of p-cresol. A response mechanism, linking the production of hydroxyl radicals and sulfate radicals. In conclusion, this investigation indicated a high potential of TiO2 suspension to remove the high-level concentration of p-cresol under UV radiation

Karbon emisyon politikalarının tersine tedarik zincir ağı tasarımı üzerindeki etkileri

Reverse Supply Chain is described as an initiative that plays an important role in the global supply chain for those who seek environmentally responsible solutions for their end-of-life products. The relative economic and environmental benefits of reverse supply chain are influenced by costs and emissions during collection, transportation, recovery facilities, disassembly, recycling, remanufacturing, and disposal of unrecoverable components. The design of reverse supply chain network takes into account social, economic and environmental objectives. This paper addresses the design of reverse supply chain under the three common regulatory policies, strict carbon caps, carbon tax, and carbon cap-and-trade.Küresel tedarik zincirinde önemli bir rol oynayan tersine tedarik zinciri, ömrünü tamamlamış ürünler için çevreye karşı sorumlu çözümler arayanların bir girişimi olarak tanımlanmaktadır. Tersine tedarik zincirinin nispi ekonomik ve çevresel faydaları, toplama, nakliye, geri kazanım tesisleri, demontaj, geri dönüşüm, yeniden imalat ve geri dönüşü olmayan bileşenlerin imha edilmesi sırasında oluşan maliyetler ve emisyonlardan etkilenmektedir. Tersine tedarik zinciri ağ tasarımı sosyal, ekonomik ve çevresel hedefleri dikkate almaktadır. Bu makale, sıkı karbon kapsülleri, karbon vergisi, karbon emisyon üst sınırı ve ticareti olmak üzere üç ortak düzenleyici politikada ters tedarik zincirinin tasarımını ele almaktadır