Graphite-polyimide composite for application to aircraft engines

A combined experimental and theoretical investigation was performed in order to (1) demonstrate that high quality angleplied laminates can be made from HT-S/PMR-RI (PMR in situ polymerization of monomeric reactants), (2) characterize the PMR-PI material and to determine the HT-S unidirectional composite properties required for composite micro and macromechanics and laminate analyses, and (3) select HT-S/PMR-PI laminate configurations to meet the general design requirements for high-tip-speed compressor blades. The results of the investigation showed that HT-S/PMR laminate configurations can be fabricated which satisfy the high-tip-speed compressor blade design requirements when operating within the temperature capability of the polymide matrix

The Accessible Toilet Resource

Extract: This Accessible Toilet Design Resource has been produced from new primary research carried out within VivaCity 2020, a large university-based research consortium that is developing tools and resources to support the design of socially inclusive cities. The consortium is funded by the Engineering and Physical Sciences Research Council (EPSRC). It was set up in 2003 and will complete its work in 2008. The Resource is concerned primarily with the design of the accessible toilet cubicle that should be provided for customer or public use wherever there is standard toilet provision. Though it may make reference to other types of toilet cubicles, urinals, automatic public conveniences (APCs) or grouped toilet provision, the location and design of these facilities are not addressed in great detail here. The location and design of accessible toilet facilities merits this independent, detailed scrutiny because it is essential to provide these facilities and to design them correctly, so that disabled people can participate on equal terms to able-bodied people in every aspect of city life

Intermediaries in Entrepot Trade: Hong Kong Re-Exports of Chinese Goods

In this paper, we examine Hong Kong's role in intermediating trade between China and the rest of the world. Hong Kong distributes a large fraction of China's exports. Net of customs, insurance, and freight charges, re-exports of Chinese goods are much more expensive when they leave Hong Kong than when they enter. Hong Kong markups on re-exports of Chinese goods are higher for differentiated products, products with higher variance in export prices, products sent to China for further processing, and products shipped to countries which have less trade with China. These results are consistent with quality-sorting models of intermediation and with the outsourcing of production tasks from Hong Kong to China. Additional results suggest that Hong Kong traders price discriminate across destination markets and use transfer pricing to shift income from high-tax countries to Hong Kong.

Radar signal return from near-shore surface and shallow subsurface features, Darien Province, Panama

The AN/APQ-97 radar imagery over eastern Panama is analyzed. The imagery was directed toward extraction of geologic and engineering data and the establishment of operational parameters. Subsequent investigations emphasized landform identification and vegetation distribution. The parameters affecting the observed return signal strength from such features are considered. Near-shore ocean phenomena were analyzed. Tidal zone features such as mud flats and reefs were identified in the near range, but were not detectable in the far range. Surface roughness dictated the nature of reflected energy (specular or diffuse). In surf zones, changes in wave train orientation relative to look direction, the slope of the surface, and the physical character of the wave must be considered. It is concluded that the establishment of the areal extent of the tidal flats, distributary channels, and reefs is practical only in the near to intermediate range under minimal low tide conditions

Risk aversion and bidding theory

Theory of bidding behavior and formation of bidding model with risk aversio

Simulated Trading for Maryland's Nitrogen Loadings in the Chesapeake Bay

We investigate nutrient trading for point and non-point sources for the Bay Restoration Fund in Maryland. We demonstrate how to use the proceeds from the tax revenue to mimic a market by trading high-cost upgrades of sewage treatment plants for low-cost winter cover crops. Under an optimistic assumption about costs for non-point sources and naïve assumptions about the lag from planting cover crops to changes in nitrogen load, we calculate that 100 percent of abatement could be achieved at 56 percent of total costs, while in a pessimistic scenario, 100 percent of abatement could be could be achieved at 83 percent of total costs.Chesapeake Bay, cover crops, nitrogen abatement, nutrient trading, sewage treatment plants, trading ratios, water pollution, Environmental Economics and Policy,

Productivity Measurement and the Impact of Trade and Technology on Wages: Estimates for the U.S., 1972-1990

We develop an empirical framework to assess the importance of trade and technical change on the wages of production and nonproduction workers. Trade is measured by the foreign outsourcing of intermediate inputs, while technical change is measured by the shift towards high-technology capital such as computers. In our benchmark specification, we find that both foreign outsourcing and expenditures on high-technology equipment can explain a substantial amount of the increase in the wages of nonproduction (high-skilled) relative to production (low-skilled) workers that occurred during the 1980s. Surprisingly, it is expenditures on high-technology capital other than computers that are most important. These results are very sensitive, however, to our benchmark assumption that industry prices are independent of productivity. When we allow for the endogeneity of industry prices, then expenditures on computers becomes the most important cause of the increased wage inequality, and have a 50% greater impact than does foreign outsourcing.

Foreign Direct Investment and Relative Wages: Evidence from Mexico's Maquiladoras

In this paper, we examine the increase in the relative wages of skilled workers in Mexico during the 1980s. We argue that rising wage inequality in Mexico is linked to capital inflows from abroad. The effect of these capital inflows, which correspond to an increase in outsourcing by multinationals from the United States and other Northern countries, is to shift production in Mexico towards relatively skill-intensive goods thereby increasing the relative demand for skilled labor. We study the impact of foreign direct investment (FDI) on the share of skilled labor in total wages in Mexico using state-level data on two-digit industries from the Industrial Census for the period 1975 to 1988. We measure the state- level growth in FDI using data on the regional activities of foreign- owned assembly plants. We find that growth in FDI is positively correlated with the relative demand for skilled labor. In the regions where FDI has been most concentrated, growth in FDI can account for over 50 percent of the increase in the skilled labor share of total wages that occurred during the late 1980s.