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Copyright of REDER: Revista de Estudios Latinoamericanos sobre Reducción del Riesgo de Desastres is the property of Corporacion Gestion de Riesgos y Desastres (GRID-Chile) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The production of wind energy via natural gas turbines and compressed air energy storage to reduce greenhouse gas emissions is analyzed.

Channels not receiving the same amount of flow (flow maldistribution) is an important effectiveness loss for high effectiveness heat exchangers. This paper develops a finite difference model of a counter flow heat exchanger. It reproduced the simple NTU result for two channels exactly. For more than two channels, there is an edge effect, and the model agreed within 0.1% of the literature. Perfect agreement was achieved for a simple flow maldistribution case. For independent pairs of hot and cold channels, as flow rate is reduced, the effectiveness asymptotically approaches the irregularity parameter (a measure of channel flow maldistribution). With thermal coupling between pairs of channels (measured by an equivalent Peclet number), effectiveness continues to increase with decreasing flow rate. These results hold for uncorrelated flow maldistribution on both sides or no flow maldistribution on one side. However, when flow maldistribution is positively correlated, effectiveness is higher; and, when it is negatively correlated, effectiveness is lower. A number of resulting graphs illustrate the effectiveness for each channel with different flow rate and correlation. While one exemplary application is a polymer expanded microchannel heat exchanger, the model could be used for other heat exchangers. [ABSTRACT FROM AUTHOR]

Recent theoretical developments in expanded microchannel polymer-based heat exchangers were promising, but the initial experiments underperformed simple theory. In order to understand this discrepancy, this article introduces a nondestructive methodology for characterizing polymer heat exchangers. A computerized tomography (X-ray) scan was performed to diagnose the problem. The method was tested on the expanded microchannel polymer heat exchanger to determine the variations in geometry between the theoretical and experimental heat exchanger. Channels were found to have variable heights causing flow maldistribution. The results are discussed to guide further technological development of this approach to heat exchanger design and fabrication and lays the groundwork for an advanced discretized modeling. [ABSTRACT FROM AUTHOR]

This study determines the nuclear pragmatic limit where the direct physical negative consequences of nuclear weapons use are counter to national interests, by assuming all unknowns are conservatively optimistic. The only effect considered is nuclear winter ("nuclear autumn" in the low weapons limits) and the resultant effects on the aggressor nation. First, the ability of low nuclear weapon limits is probed for maintaining deterrence in the worst-case scenario of attacking the most-populous nation. Second, the ability of aggressor nations to feed themselves is assessed without trade and industry resultant from a nuclear attack causing "nuclear autumn" (10% global agricultural shortfall). Third, the best-case wealthy aggressor nation with abundant arable land is analyzed for starvation and economic impacts given 7000, 1000, and 100 nuclear weapons scenarios. The results found that 100 nuclear warheads is adequate for nuclear deterrence in the worst case scenario, while using more than 100 nuclear weapons by any aggressor nation (including the best positioned strategically to handle the unintended consequences) even with optimistic assumptions (including no retaliation) would cause unacceptable damage to their own society. Thus, 100 nuclear warheads is the pragmatic limit and use of government funds to maintain more than 100 nuclear weapons does not appear to be rational. [ABSTRACT FROM AUTHOR]

In this work, solar radiation availability has been estimated for south‐facing inclined surfaces in India. Five different climatic zones prescribed by Energy Conservation Building Code (ECBC) for India have been considered. A comparison of optimum tilt angles and corresponding incident solar radiation for representative locations under different climatic zones, that is, Srinagar (cold), Delhi (composite), Jodhpur (hot and dry), Mumbai (warm and humid), and Bangalore (Temperate) has been established. Gains in the availability of incident solar radiation in comparison with a horizontal surface observed for Jodhpur and Bangalore were found to be maximum (15.77%) and minimum (7.57%), respectively, on monthly optimum tilt angle. A loss of 5.74% for cold climate, 7.49% for composite climate, 6.16% for hot and dry climate, 4.30% for warm and humid climate, and 4.39% for temperate climate were estimated with surface tilted at annual optimum tilt in comparison with a surface at monthly optimum tilt angle. A linear relationship was observed between annual optimum tilt angles and locations latitude as βopt(annual) = 0.671 ϕ + 9.087 with R2 = 0.9984. It was concluded that climatic conditions can considerably affect the availability of incident solar radiation under different climatic zones. ' 2018 American Institute of Chemical Engineers Environ Prog, 38:e13050, 2019 [ABSTRACT FROM AUTHOR]