Engineering
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Modeling and Simulation for Pressure Swing Adsorption System for Hydrogen Purification
Electrical Engineering Journal: Despite tremendous growth in practical applications of this technology, the design of PSA system is more of an experimental basis. The realistic model of a PSA cycle consists of flow rate which varies due to significant adsorption, while the heat effect needs also to be considered due to adiabatic thermal conditions. In this paper, an effort has been made to model and simulate a PSA cycle for hydrogen purification. For this purpose, a system consisting of 4 beds and 8 stages was considered using beds of activated carbon and zeolite. The PSA process for hydrogen purification uti-lizes different loading capacities of adsorbent at different pressures to separate a gas mixture into its components. The loading capacity of an adsorbent is the amount of gas that can be bound by mass unit of the adsorbent material. The extent to which an adsorbent can be loaded increases in general with the partial pressure of the gas component.
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Role of DeNOx Catalyst in PCDD/F Emission Reduction in HazardousWaste Incineration
On the basis of nine periodical measurements, emissions of PCDD/F have been analysed. As a result, a correlation was detected between elevated PCDD/F emissions and operational problems with selective catalytic reduction (SCR) system. The air pollution control system (APCS) consisted of dry scrubbing system (mixture of active carbon and NaHCO3), fabric filter, DeNOx catalyst and wet scrubber. It was assumed that such a state-of-the-art system should be able to achieve dioxin emission limit of 0.1 ng Nm–3 I-TEQ, even without DeNOx catalyst. However, this expectation proved to be wrong. The presence of memory effect was recognized as the possible cause of elevated PCDD/F emissions. During normal operational periods presence of memory effect was not noticed, due to selective catalytic reduction system. With malfunction of DeNOx catalyst, this effect escalated, causing elevated PCDD/F emissions.
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European Engineering Journal Collection 2010
Mechanical and Environmental Engineering Journal: The present work focuses on experimental and numerical investigations of the augmentation of turbulent flow heat transfer in a horizontal circular tube by means of mesh inserts with air as the working fluid. The results are compared with the clear flow case when no porous material was used. CFD techniques were also employed to perform optimization analysis of the mesh inserts. The horizontal tube along with mesh inserts was modeled in Gambit 2.2.30 with fine meshing and analyzed using FLUENT 6.2.16. CFD analysis was performed initially for plain tube and the results are compared with experimental values for validation.
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Journal of Management of High-Throughput DNA Sequencing Projects: Alpheus
High-throughput DNA sequencing has enabled systems biology to begin to address areas in health, agricultural and basic biological research. Concomitant with the opportunities is an absolute necessity to manage significant volumes of high-dimensional and interrelated data and analysis. Alpheus is an analysis pipeline, database and visualization software for use with massively parallel DNA sequencing technologies that feature multigigabase throughput characterized by relatively short reads, such as Illumina-Solexa (sequencing-by-synthesis), Roche454 (pyrosequencing) and Applied Biosystem’s SOLiD (sequencing-by-ligation). Alpheus enables alignment to reference sequence(s), detection of variants and enumeration of sequence abundance, including expression levels in transcriptome sequence.
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Nuclear Power Development: International Trade & Waste and Fuel Management
Nuclear cooperation between different nations has been an element of nuclear power development and operation since the earliest days of the nuclear power. Nuclear cooperation has taken different forms and has served a variety of purposes.
Contents: Developments in International Nuclear Cooperation, Reviving American Nuclear Industry, An Opportunity for US to Lead by Example, Supporting Advanced Fuel Technologies, Nuclear Power for Process Heat Applications, $2.38 Million Savings with Simple Innovation, $50 Million/Plant Savings with
IN-SITU Epoxy Coating, Improved Service Water Performance with Polyethylene Piping, Supporting 1,000 Well-Paying Jobs.
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Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
Integrated energy, environment and economics modeling suggests electrical energy use will increase from 2.4 TWe today to 12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources. Thus nuclear power may be needed to provide ~30% by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting.
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Mesoporous Silicate Materials as Substrates for Molecular Machines and Drug Delivery
Mesoporous silica thin films and nanoparticles prepared by surfactant-templated sol–gel techniques are versatile substrates that can be easily derivatized with active molecules to create functional materials. By exploiting the chemical and physical differences that exist in different regions of the mesostructure, active molecules can be deliberately placed using one-pot techniques, or they can be tethered to the exposed surfaces postsynthetically. The methods available for functionalization have been used to design operational machines including nanoimpellers based on the dynamic photoisomerization of azobenzene, and nanovalves based on the switchable motion of supramolecular rotaxanes and pseudorotaxanes. The ability of nanoimpellers and nanovalves to control the release of molecules from the pores of mesoporous silica materials is demonstrated using luminescence spectroscopy.
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Proactive product quality control: An integrated product and process control approach to MIMO systems
Real-time control of product performance parameters is a key for proactive quality control (QC), as it can prevent the occurrence of potential quality problems in the earliest stage of manufacturing. It is recognized that dynamic product QC must be coordinated with the control of the process through which the product is manufactured. The integrated product and process control (IPPC) design methodology introduced recently is a proven approach to the simultaneous control of both the product quality and the process performance.
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Free Engineering Journal - Steel Fabrication Costs in China
Main Issues : Steel Fabrication Costs in China, As its economy develops, China is moving from the manufacturing of small consumer goods into larger, sophisticated products, such as fabricated structural steel. Contractors bidding on fixed-price contracts rely on lower quotes for Chinese steel products. However, our case study indicates that the true cost of steel fabrication in China may not be as low as China’s basic labor rates suggest, and owners may find themselves paying higher prices than expected for change orders. A Monte Carlo model was developed to forecast the labor cost of steel fabrication for a bridge, to compensate the fabricator for change-order work, and to allow the project’s management to assess acceleration alternatives. It takes into account current Chinese national and local labor laws, company benefits, and work schedules. The model results support the use of a “two-thirds” rule of thumb to estimate Chinese steel fabrication costs at two-thirds of the US costs. This article is reprinted from the 2010 Transactions.
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Aircraft Tool Control Technical Manual - Organizational Maintenance
The purpose of this manual is to present the Tool Control Program for Naval and Marine aviation organizational maintenance activities. The prime objective of the Tool Control Program is the prevention of aircraft accidents, incidents, and foreign object damage, which have cause factors of tools adrift. Additional benefits that will be realized by compliance with the procedures contained herein are the reduction of pilferage, initial outfitting costs, in-use inventories, tool replacement costs, and maintenance manhours. All of these reductions make significant contributions to cost effectiveness. This manual divided into sections as follow: introduction, estabilishing and operating instrument, materials, container descriptions and typical uses, container hardware, additional information, pwer plants tool lists and container layouts, tool listing.
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