12,834 research outputs found
Development and integration of the capillary pumped loop GAS and Hitchhiker flight experiments
The Capillary Pumped Loop (CPL) is a thermal control system with high density heat acquisition and transport capability. A small spaceflight version of the CPL was built and flown as a GAS experiment on STS 51-D in April 1985 and STS 51-G in June 1985, and as a Hitchhiker-G experiment on STS 61-C in January 1986. The purpose of the experiments was to demonstrate the capability of a capillary pumped system under microgravity conditions for use in the thermal control of large scientific instruments, advanced orbiting spacecraft, and space station components. The development, integration, and test activities of the CPL are described
NONCONSTANT PRICE EXPECTATIONS AND ACREAGE RESPONSE: THE CASE OF COTTON PRODUCTION IN GEORGIA
An adaptive regression model is used to examine the relative importance of cash and government support prices in determining cotton production over time. The results show that the cash price is more important as a source of price information for cotton producers than the government program price. The cash price was shown to have a greater influence on acreage response in every year, including periods thought to be dominated by government commodity programs.Adaptive regression, Cotton acreage response, Price expectations, Crop Production/Industries,
REIT Pricing Efficiency; Should Investors Still Be Concerned?
This study examines the impact of the REIT boom on the market microstructure of REIT common stocks. We analyze NYSE-traded REITs during the pre-boom period (1992) and the post-boom period (1994), and find significant reductions in bid/ask spreads over the period. We also find that the bid/ask spread differential between REITs and non-REITs has been roughly halved between 1991 and 1994. These reductions provide a direct benefit to REIT investors in terms of reduction in transaction costs and improved liquidity, and suggest that the level of uncertainty on the part of the REIT specialist has been reduced.
An Examination of Informed Traders and the Market Microstructure of Real Estate Investment Trusts
A significant body of research exists documenting that REITs perform differently from other types of equity securities, although the reasons for these differences are unclear. This study examines the intraday trading behavior of Real Estate Investment Trusts (REITs). Specifically, intraday REIT returns, volume, trading activity, and bid/ask spread are examined in an attempt to better understand the patterns of intraday information flow for a sample of REITs trading on the NYSE. After controlling for differences in market capitalization, share price, and institutional holdings, this paper analyzes differences between REITs and non-REITs, and between REITs that are widely held by institutions and those that are not. The results suggest that, as a group, REITs exhibit lower average volumes and number of trades than do similar non-REITs. In addition, the findings suggest that mortgage REITs trade at spreads that are wider. Surprisingly, the analysis of institutional ownership suggests that equity REITs that are widely held by institutions exhibit the largest divergence from non-REITs in terms of both intraday trading activity and volume, but at the same time trade closer to non-REITs in terms of bid/ask spread. Overall, the results of this study confirm that REITs are treated differently by investors than similar non-REITs, and the institutional ownership findings suggest that trading activity is less important as a determinant of REIT performance than is the level of institutional ownership.
Prehension and perception of size in left visual neglect
Right hemisphere damaged patients with and without left visual neglect, and age-matched controls had objects of various sizes presented within left or right body hemispace. Subjects were asked to estimate the objects’ sizes or to reach out and grasp them, in order to assess visual size processing in perceptual-experiential and action-based contexts respectively. No impairments of size processing were detected in the prehension performance of the neglect patients but a generalised slowing of movement was observed, associated with an extended deceleration phase. Additionally both patient groups reached maximum grip aperture relatively later in the movement than did controls. For the estimation task it was predicted that the left visual neglect group would systematically underestimate the sizes of objects presented within left hemispace but no such abnormalities were observed. Possible reasons for this unexpected null finding are discussed
Invited commentary on Stewart and Davis " 'Big data' in mental health research-current status and emerging possibilities"
No abstract available
Cost-effective use of liquid nitrogen in cryogenic wind tunnels, phase 2
Cryogenic seal tests were performed and Rulon A was selected for the subject nutating positive displacement expander. A four-chamber expander was designed and fabricated. A nitrogen reliquefier flow system was also designed and constructed for testing the cold expander. Initial tests were unsatisfactory because of high internal friction attributed to nutating Rulon inlet and outlet valve plates. Replacement of the nutating valves with cam-actuated poppet valves improved performance. However, no net nitrogen reliquefaction was achieved due to high internal friction. Computer software was developed for accurate calculation of nitrogen reliquefaction from a system such as that proposed. These calculations indicated that practical reliquefaction rates of 15 to 19 percent could be obtained. Due to mechanical problems, the nutating expander did not demonstrate its feasibility nor that of the system. It was concluded that redesign and testing of a smaller nutating expander was required to prove concept feasibility
Calixarene-supported clusters:employment of complementary cluster ligands for the construction of a ferromagnetic [Mn<sub>5</sub>] cage
A combination of complementary cluster ligands results in the formation of a new calixarene-supported ferromagnetic [Mn5] cage that displays the characteristic bonding modes of each support.</p
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