Application of moderate resolution band models to the prediction of heat transfer from rocket exhaust plumes

Computer program for resolution band model prediction of heat transfer from rocket exhaust plume

New technique to measure the cavity defects of Fabry-Perot interferometers

(Abridged): We define and test a new technique to accurately measure the cavity defects of air-spaced FPIs, including distortions due to the spectral tuning process typical of astronomical observations. We further develop a correction technique to maintain the shape of the cavity as constant as possible during the spectral scan. These are necessary steps to optimize the spectral transmission profile of a two-dimensional spectrograph using one or more FPIs. We devise a generalization of the techniques developed for the so-called phase-shifting interferometry to the case of FPIs. The technique is applicable to any FPI that can be tuned via changing the cavity spacing ($z$-axis), and can be used for any etalon regardless of the coating' reflectivity. The major strength of our method is the ability to fully characterize the cavity during a spectral scan, allowing for the determination of scan-dependent modifications of the plates. As a test, we have applied this technique to three 50 mm diameter interferometers, with cavity gaps ranging between 600 micron and 3 mm, coated for use in the visible range. We obtain accurate and reliable measures of the cavity defects of air-spaced FPIs, and of their evolution during the entire spectral scan. Our main, and unexpected, result is that the relative tilt between the two FPI plates varies significantly during the spectral scan, and can dominate the cavity defects; in particular, we observe that the tilt component at the extremes of the scan is sensibly larger than at the center of the scan. Exploiting the capability of the electronic controllers to set the reference plane at any given spectral step, we develop a correction technique that allows the minimization of the tilt during a complete spectral scan. The correction remains highly stable over long periods, well beyond the typical duration of astronomical observations.Comment: 15 pages, 20+ figures, accepted for publication in A&A. Two additional movies are available in the online version of the pape

Impacts of Agrifood Market Transformation during Globalization on the Poor's Rural Nonfarm Employment: Lessons for Rural Business Development Programs

Consumer/Household Economics, Resource /Energy Economics and Policy,

Impacts of Agrifood Market Transformation during Globalization on the Poor's Rural Nonfarm Employment: Lessons for Rural Business Development Programs

This paper presents emerging evidence pointing to the transmission to developing countries' rural spaces of the impacts of agrifood market transformation occurring at national and global levels. That transmission takes place via retail chains penetrating intermediate cities and rural towns, and urban-based food manufacturers selling products to those chains as well as to traditional shops. The paper presents and justifies three main hypotheses concerning the impacts of that penetration. (1) The direct effect is that the modern retailers and modern-sector processed products directly compete with, and present potentially major challenges to, the processed foods, farm inputs, and commercial services already being undertaken in the RNFE sector by the rural poor among others. (2) The indirect effects is that modern sector firms tend, once they have "modernized" their procurement systems, to prefer larger suppliers if available, and/or small suppliers that have the requisite levels of capital assets. This further translates to a potential labor substitution bias, in particular of unskilled labor, although it may drive skilled labor demand. (3) The production and consumption linkage effects of the above impacts on RNFE firms, laborers, and farmers, all else equal, probably implies greater demand for non-tradeable goods and services in the RNFE that correspond to the demand patterns of the upper stratum of rural consumers. Faced with the above, what can business development programs do? (1) Given the change in the market context, it will be increasingly undesirable and "un-strategic," except in the most remote, hinterland areas, to maintain the separation between competitiveness and nonfarm employment programs. At least for RNF activities that supply processed products, farm inputs, and retail commerce, RNF enterprises will need to face the same general challenge that exporters in their country face on the global market, and urban firms face, which is to compete on cost and quality. (2) Second, maintaining the analogy to international competitiveness, it will be necessary go beyond a generic competitiveness approach, to employ a "customized competitiveness" strategy (a term used by Reardon and Flores 2006 for export programs, but applicable here). Such an approach focuses on understanding the specific requirements of transformed markets and building the capacity of particular groups to respond to those requirements (as suppliers) or match cost and quality and compete for specific niches. The capital assets that programs should building include market intelligence capital, organizational capital, technology capital, and financial (and risk reduction) capital. (3) In the economic transformation, this time in the rural space, the poorest, those with least assets, are again vulnerable. Special attention should be paid to equipping those households and firms to participate in the increasingly challenging rural nonfarm economy.Community/Rural/Urban Development,

Bilateral attentional advantage on elementary visual tasks

We examined interactions between and within the left and right visual hemifields using elementary visual tasks. Each trial required identifying a letter at fixation and then either discriminating the orientation of (experiment I) or detecting (experiment 2) peripheral Gabor targets. On half the trials Gabor distracters were presented between the Gabor targets, and were either restricted to one lateral hemifield (unilateral condition) or presented across the left and right hemifields (bilateral condition). Orientation discrimination and detection each exhibited bilateral superiority only when distracters were present. The results confirm bilateral superiority in attentional selection, even on these most elementary visual tasks. (C) 2009 Elsevier Ltd. All rights reserved

Racking Performance of Plasterboard-Clad Steel Stud Walls

It is recognised that structural design efficiency in domestic and similar structures can be improved when the composite behaviour and contribution of all materials in the permanent structure can be fully recognised in the structural design of the frame. The ability to achieve this Improvement is currently limited by the need 10 rely on empirical test results for standardised building elements when considering the composite behaviour of the entire structure. The existing test methodology for determining the shear strength of plasterboard lined steel stud walls leads to an excessively conservative design of the complete structure. Since the test configuration is for isolated test panels, the absence of continuity of the plasterboard lining around a set corner is not included in the test procedure. A test program has been devised and carried out to explore the effect of the set corner on the performance of shear test panels. A dramatic improvement in both diaphragm shear strength and shear stiffness has been achieved in these tests supporting a proposal to amend the standard lest methodology to Include set corners

Commentary on “Critical Appraisal of Published Systematic Reviews Assessing the Cost-Effectiveness of Telemedicine Studies”

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140283/1/tmj.2014.9980.pd