Ruler for making navigational computations

An extensive ruler used as a computer in navigation to calculate travel time between map points or to calculate ground speed is described. The ruler has a time scale that can be adjusted at length to equal map distances travelled at a designated speed in a time period such as sixty minutes. A means for fixing the length of the ruler is also provided

Crossflow vorticity sensor

A crossflow vorticity sensor for the detection of crossflow vorticity characteristics is described. The sensor is comprised of crossflow sensors which are noninvasively adhered to a swept wing laminar surface either singularly, in multi-element strips, in polar patterns, or in orthogonal patterns. These crossflow sensors are comprised of hot-film sensor elements which operate as a constant temperature anemometer circuit to detect heat transfer rate changes. Accordingly, crossflow vorticity characteristics are determined via cross-correlation. In addition, the crossflow sensors have a thickness which does not exceed a maximum value h in order to avoid contamination of downstream crossflow sensors

Wind and solar powered turbine

A power generating station having a generator driven by solar heat assisted ambient wind is described. A first plurality of radially extendng air passages direct ambient wind to a radial flow wind turbine disposed in a centrally located opening in a substantially disc-shaped structure. A solar radiation collecting surface having black bodies is disposed above the fist plurality of air passages and in communication with a second plurality of radial air passages. A cover plate enclosing the second plurality of radial air passages is transparent so as to permit solar radiation to effectively reach the black bodies. The second plurality of air passages direct ambient wind and thermal updrafts generated by the black bodies to an axial flow turbine. The rotating shaft of the turbines drive the generator. The solar and wind drien power generating system operates in electrical cogeneration mode with a fuel powered prime mover

Boundary layer measurements using hot-film sensors

Measurements in the aerodynamic boundary layer using heat transfer, hot-film sensors are receiving a significant amount of effort at the Langley Research Center. A description of the basic sensor, the signal conditioning employed, and several manifestations of the sensor are given. Results of a flow reversal sensor development are presented, and future work areas are outlined

Volunteers and volunteering in leisure : social science perspectives

Leisure has been widely examined within the context of social science theory; however, little work has considered the range of social science disciplines and applied them to specific phenomena located within the leisure field. This paper adopts such an approach to conceptualise and examine volunteers and volunteering in leisure settings. In a disciplinary sense, therefore, the sociological view focuses upon the conceptualisation of volunteering as leisure, the psychological view seeks to understand motivations driving volunteering while the perspective of economists tends to complement these standpoints in terms of why people volunteer and further examines the value of volunteer contributions. Comparative analysis of the perspectives enunciated within these key disciplines provides a picture of the status of research relating to leisure volunteers and volunteering. The purposes of this paper are to identify gaps in current knowledge, drawing out conclusions and their implications for an improved understanding of this area as well as to enhance comprehension of disciplinary contributions to the study of leisure phenomena

REIT Stock Repurchases: Completion Rates, Long - Run Returns, and the Straddle Hypothesis

This study of real estate investment trusts (REITs) analyzes three possible explanations for the stock price reaction to a repurchase announcement and the subsequent repurchase behavior of managers under each hypothesis. Two of the hypotheses, the signaling hypothesis and the exchange option hypothesis, are established in the existing literature; the third hypothesis is a modification of the exchange option hypothesis. The exchange option hypothesis is extended to allow for additional flexibility in management decisions. This extended exchange option hypothesis is termed the ‘‘straddle’’ hypothesis because it provides management with both a call and put option. The empirical analyses show the straddle hypothesis is a more robust explanation of changes in shares outstanding in the postannouncement period than the alternative explanations.

"If We Don't Produce, Bring Another:" Work Organization and Tomato Worker Health.

Objectives: Specific work processes and management structures that contribute to high rates of occupational illness and injury in agricultural industries are not well described in academic literature. This qualitative study of work organization in the U.S. fresh tomato industry investigates how work processes and management structures impact tomato workers' occupational health. Methods: After conducting literature review and key informant interviews, semi-structured interviews and focus groups were conducted with 36 individuals with experience working in the U.S. fresh tomato industry. Interviews and focus groups were audio-recorded, transcribed, coded, and analyzed using a modified grounded theory approach. Results: These data indicate that participants endured income insecurity and hazardous supervisory practices, including wage theft, retaliation, intimidation, and humiliation, that put them at risk of preventable illness and injury. Support from workers' organizations and health-conscious supervisory practices helped mitigate some of these occupational hazards. Conclusion: Participants' adverse work experiences may be considered sequelae of workers' lack of job control and positions of socioeconomic structural vulnerability. Other aspects of tomato work organization, including health-conscious supervisory practices and the involvement of workers' organizations, indicate that modifying work organization to better safeguard health is possible. Such modifications present compelling opportunities for employers, employees, organizations, community and government leaders, and health care professionals to help create healthier occupational environments for tomato workers