76,031 research outputs found
Slot configuration for axial-flow turbomachinery blades
Machining of slot in turbine blades of axial flow turbines to provide flow path between pressure and suction surfaces is discussed. Slot configuration and improvements in blade performance are described. Diagram of blade slot to show geometry of modification is included
Solar cell metallization: Historical perspective
Solar cell metallization design requirements are discussed. Space applications and terrestrial applications are considered. Cost factors are discussed in relation to design analysis
Demonstration of the feasibility of automated silicon solar cell fabrication
An analysis of estimated costs indicate that for an annual output of 4,747,000 hexagonal cells (38 mm. on a side) a total factory cost of 1.22 per watt of electrical output. A laboratory model of such a facility was operated to produce a series of demonstration runs, producing hexagonal cells, 2 x 2 cm cells and 2 x 4 cm cells
Research study of space plasma boundary processes
Representation of the Earth's bow shock and magnetopause and their geometrically determined macrostructure was investigated. Computer graphic depictions of the global distributions of bow shock structures and elementary animation of the dynamics of those distributions in the changing solar wind were developed. The shock-foreshock boundary and subcritical bow shocks as observed by ISEE 1 and 2 are discussed
Novel convolution-based signal processing techniques for an artificial olfactory mucosa
As our understanding of the human olfactory system has grown, so has our ability to design artificial devices that mimic its functionality, so called electronic noses (e-noses). This has led to the development of a more sophisticated biomimetic system known as an artificial olfactory mucosa (e-mucosa) that comprises a large distributed sensor array and artificial mucous layer. In order to exploit fully this new architecture, new approaches are required to analyzing the rich data sets that it generates. In this paper, we propose a novel convolution based approach to processing signals from the e-mucosa. Computer simulations are performed to investigate the robustness of this approach when subjected to different real-world problems, such as sensor drift and noise. Our results demonstrate a promising ability to classify odors from poor sensor signals
Navigation system and method
In a global positioning system (GPS), such as the NAVSTAR/GPS system, wherein the position coordinates of user terminals are obtained by processing multiple signals transmitted by a constellation of orbiting satellites, an acquisition-aiding signal generated by an earth-based control station is relayed to user terminals via a geostationary satellite to simplify user equipment. The aiding signal is FSK modulated on a reference channel slightly offset from the standard GPS channel. The aiding signal identifies satellites in view having best geometry and includes Doppler prediction data as well as GPS satellite coordinates and identification data associated with user terminals within an area being served by the control station and relay satellite. The aiding signal significantly reduces user equipment by simplifying spread spectrum signal demodulation and reducing data processing functions previously carried out at the user terminals
The Green Entrepreneur: Visionary, Maverick or Opportunist?
Given the importance of green entrepreneurs in the transition towards a truly sustainable society, this paper proposes frameworks for investigating the motives of entrepreneurs who set up green businesses. Different perceptions of 'green' are explored and although the paper focuses particularly on 'green-green' businesses, the scope for investigation encompasses all possible forms of green start-ups. The main approach taken in the paper is to review the literature on entrepreneurs generally, and approaches to classifying entrepreneurs with a view to gaining useful insights for the green context. An exploratory typology of green entrepreneurs is proposed, which has been adapted and developed from Thompson's four dimensions of entrepreneurship (1998). The terms 'ethical maverick', 'ad hoc environpreneur', 'visionary champion' and 'innovative opportunist' are coined to describe different motives or orientations of the green entrepreneur. Frameworks are proposed to investigate the motives of, and influences on, green entrepreneurs. The ultimate aim is to gain insights for policy makers and educators into ways to foster green entrepreneurship.entrepreneurship, sustainability, green, start-ups, motivation, typology
Adiabatic motion of auroral particles in a model of the electric and magnetic fields surrounding the earth
Adiabatic motion of auroral particles in model of earth electric and magnetic fiel
Demonstration of the feasibility of automated silicon solar cell fabrication
A study effort was undertaken to determine the process, steps and design requirements of an automated silicon solar cell production facility. Identification of the key process steps was made and a laboratory model was conceptually designed to demonstrate the feasibility of automating the silicon solar cell fabrication process. A detailed laboratory model was designed to demonstrate those functions most critical to the question of solar cell fabrication process automating feasibility. The study and conceptual design have established the technical feasibility of automating the solar cell manufacturing process to produce low cost solar cells with improved performance. Estimates predict an automated process throughput of 21,973 kilograms of silicon a year on a three shift 49-week basis, producing 4,747,000 hexagonal cells (38mm/side), a total of 3,373 kilowatts at an estimated manufacturing cost of 1.22 per watt
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