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41.
It is becoming more important to realize CO2‐capturing power generation systems (PGSs) for drastically decreasing an amount of CO2 emission into the atmosphere. However, net power generation efficiency (NPGE) of a CO2‐capturing system has been considered to be greatly deteriorated, since capturing CO2 requires extra energy. This paper proposes a new CO2‐capturing PGS that has a high‐efficient NPGE by utilizing waste heat from factories. As an example of a waste heat, exhaust gas with temperature 200°C from refuse incinerator plants is adopted. In the proposed system, the temperature of saturated steam produced by utilizing the waste heat is raised by combusting fuel with the use of pure oxygen in a combustor, and is used as the main working fluid of a gas turbine PGS. It is estimated that the proposed system has a fuel‐to‐electricity NPGE of 59.3%, when turbine inlet temperature (TIT) is assumed to be 1000°C. The economics of the proposed system is also evaluated and the CO2 reduction cost is estimated to be small; 4.16 U.S. $ t−1 CO2 compared with 32.1 U.S. $ t−1 CO2 for a conventional steam turbine PGS. It is shown that CO2‐capturing is not cost consuming but becomes to be profitable owing to improved power generation characteristics, when its TIT is increased from 1000 to 1200°C. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
42.
Shin H Lee KM Moon WK Jeon JU Lim G Pak YE Park JH Yoon KH 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2000,47(4):801-807
The feasibility of utilizing PZT films as future data storage media was investigated using a modified AFM. Applying voltages between a conductive AFM tip and the PZT films causes the switching of ferroelectric domains. The domains are observed using an EFM imaging technique. The experimental results and calculations revealed that the electrostatic force generated between the polarized area and the tip is a main contributor for the imaging of the polarized domains. The written features on ferroelectric films were less than 100 nm in diameter, implying the possibility of realizing data storage devices with ultra-high area density. The disappearance of the polarized images without any applied voltage was observed, which is a drawback in this application of PZT thin films. 相似文献
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Eui-Jun Kim Jong-Jin Pak Byung-Don You 《Metallurgical and Materials Transactions B》2001,32(4):659-668
The nitrogen solubilities in liquid manganese, manganese-iron, manganese-carbon, and manganese-iron-carbon alloys have been
measured by the gas-liquid metal equilibration technique in the temperature range of 1623 to 1823 K. The equilibrium nitrogen
content in pure liquid manganese at an atmospheric nitrogen pressure is high, and it does not follow Sievert’s law, i.e., f
N is not unity. The reduced nitrogen partial pressures by dilution with argon enabled us to obtain more reliable information
on the thermodynamics of nitrogen in liquid manganese. The nitrogen dissolution follows Sievert’s law at nitrogen contents
below 1 wt pct. The standard free-energy change for the dissolution of nitrogen in pure liquid manganese has been determined
as −67,222+30.32T J/g atom, with the standard state of nitrogen taken as a 1 wt pct solution. Carbon and iron in manganese-rich melts decrease
the nitrogen solubility significantly. The first- and second-order interaction parameters between nitrogen and other elements
in manganese alloy melts have been determined. The activity coefficient of nitrogen in a ferromanganese alloy melt can be
expressed as
where the interaction parameters are independent of temperature in the temperature range of 1623 to 1823 K. 相似文献
47.
Two-dimensional (2D) crystals have a multitude of forms,including semi-metals,semiconductors,and insulators,which are ideal for assembling isolated 2D atomic materials to create van der Waals (vdW) heterostructures.Recently,artificially-stacked materials have been considered promising candidates for nanoelectronic and optoelectronic applications.In this study,we report the vertical integration of layered structures for the fabrication of prototype non-volatile memory devices.A semiconducting-tungsten-disulfide-channel-based memory device is created by sandwiching high-density-of-states multi-layered graphene as a carrier-confining layer between tunnel barriers of hexagonal boron nitride (hBN) and silicon dioxide.The results reveal that a memory window of up to 20 V is opened,leading to a high current ratio (>103) between programming and erasing states.The proposed design combination produced layered materials that allow devices to attain perfect retention at 13% charge loss after 10 years,offering new possibilities for the integration of transparent,flexible electronic systems. 相似文献
48.
The effect of feeding 24 to 52-days-old male rats of the Wistar strain, with beans diet deficient in sulfur-containing amino acids or supplemented with 0.3% DL-methionine and two corn oil concentrations, 2% and 20% (g/kg/diet), on the glutathione content (GSH) in liver, and on the renal gamma glutamyl transpeptidase (GGTP) (E.C.2.3.2.2) activity was studied. Results indicated that rats fed the bean diet with 2% corn oil decreased significantly the liver GSH content and GGTP renal activity. Supplementation with 0.3% methionine and/or the 20% increment of the diet corn oil, significantly stimulated the liver GSH content and the transpeptidase activity in the kidney. It is postulated that the increase of polyunsaturated fatty acids, stimulated the GGTP activity as a way of increasing substrate bioavailability for synthesis de novo of liver GSH, necessary for the protection of the hydroperoxides formation, attributed to the increment of polyunsaturated acids at cellular level. 相似文献
49.
The purpose of the present study was to evaluate the amino acid score adjusted by digestibility to estimate protein quality and utilizable protein in foods and diets, considering net protein utilization (NPU) as a biological reference method. Ten foods of vegetable origin and ten of animal origin, as well as eight mixtures of foods of vegetable and animal origin were studied. When all the foods were considered, a positive (r = 0.83) and highly significant correlation (p less than 0.001) between NPU and the amino acid score adjusted by digestibility was found. When the foods were separated according to their origin, this correlation was positive only for the foods of vegetable origin (r = 0.93) and statistically significant (p less than 0.001). Also, only in those foods were similar values found between NPU and amino acid score adjusted by digestibility, as well as in utilizable protein estimated considering both methods. Caution is required to interpret protein quality and utilizable protein values of foods of animal origin and mixtures of foods of vegetable and animal origin when the amino acid score method adjusted by digestibility, or NPU, are utilized. 相似文献
50.
An optimal planning problem of a co-generation plant is studied which is constructed by combining gas turbine generators, waste heat boilers, auxiliary boilers, etc. The planning problem proposed is to determine the optimal configuration of the plant equipment taking into account the optimal operational policy of the plant for the annual energy demands of electric power and heat given a priori. Based on the annual cost method, the long-term economics of the plant is evaluated by the annual total cost, which is the objective function to be minimized. This optimal planning problem is formulated as a mixed-integer linear programming problem, and the optimal solution is derived by adopting the branch and bound method. As a result, both the configuration of the plant equipment and the operational policy are optimally determined reflecting the difference in economics and efficiency of the scale of each equipment. In addition, both the power to be purchased and the value of maximum contract demand of the purchased power is optimally determined. Using a numerical example, the validity and effectiveness of the optimal planning method proposed here is ascertained. 相似文献