5,460 research outputs found
Economic considerations of utilizing small wind generators
The economic feasibility of small wind generators is compared to that of solar cells, primary batteries, thermoelectric generators, and engine generators. It is shown that small wind generator plants offer an attractive alternative to primary battery systems and constantly running engines to generate power in remote areas. The limitation is an annual average wind velocity of at least 9 to 10 mph. Presently available units are most useful in the average load range of 10 to 1000 watts
The ethics of forgetting in an age of pervasive computing
In this paper, we examine the potential of pervasive computing to create widespread
sousveillance, that will complement surveillance, through the development of lifelogs;
socio-spatial archives that document every action, every event, every
conversation, and every material expression of an individual’s life. Examining lifelog
projects and artistic critiques of sousveillance we detail the projected mechanics
of life-logging and explore their potential implications. We suggest, given that lifelogs
have the potential to convert exterior generated oligopticons to an interior
panopticon, that an ethics of forgetting needs to be developed and built into the
development of life-logging technologies. Rather than seeing forgetting as a
weakness or a fallibility we argue that it is an emancipatory process that will free
pervasive computing from burdensome and pernicious disciplinary effects
The dynamic stiffness of a pneumatic tire model
Dynamic stiffness of pneumatic tire model - response of rotating cylindrical shell to stationary point loa
Calibration of a gamma-ray telescope using tagged position annihilation photons
Measurements of detection efficiency, angular resolution, and energy resolution properties of a gamma ray telescope used to study celestial gamma rays from balloon flight altitudes are described. Nearly monochromatic photons produced at the National Bureau of Standards tagged photon facility were used for the calibration. Details of the photon beam configuration and properties and results of the measurements made at photon energies of 15.1 and 31.1 MeV are presented. Finally, the data are compared with a Monte Carlo analysis of the instrument properties
Study of liquid jet impingement on screens
A model is presented for an unconfined flow, such as a free jet, impinging on a screen which incorporates the influence of liquid deflection by the screen. The boundary layer blockage coefficient is introduced. This coefficient depends on the screen weave geometry and the jet impingement angle, and essentially accounts for the increase in fluid particle trajectory length through the screen resulting from the flow deflection. Comparisons were made with previous experimental studies to determine empirical values of the blockage coefficient. It is concluded that the new model reliably predicts the bulk flow and penetration characteristics of an impinging liquid jet interacting with a screen
Simulated low-gravity sloshing in spherical tanks and cylindrical tanks with inverted ellipsoidal bottoms
Simulated low gravity sloshing in spherical and cylindrical tanks with inverted ellipsoidal bottom
Heat generation in aircraft tires under free rolling conditions
A method was developed for calculating the internal temperature distribution in an aircraft tire while free rolling under load. The method uses an approximate stress analysis of each point in the tire as it rolls through the contact patch, and from this stress change the mechanical work done on each volume element may be obtained and converted into a heat release rate through a knowledge of material characteristics. The tire cross-section is then considered as a body with internal heat generation, and the diffusion equation is solved numerically with appropriate boundary conditions of the wheel and runway surface. Comparison with data obtained with buried thermocouples in tires shows good agreement
Low-gravity sloshing in rectangular tanks
Low-gravity sloshing in rectangular tank
Propellant dynamics in an aircraft-type launch vehicle
Liquid propellant sloshing in tilted axisymmetric cylindrical tanks for space shuttle application
Equivalent mechanical model of propellant sloshing in the workshop configuration of the Saturn S-4B Final report
Mechanical model for propellant sloshing in irregular compartmentation of S-4B Workshop configuration during roll and lateral excitation
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