4,793 research outputs found
Photographic image enhancement and processing
Image processing techniques (computer and photographic) are described which are used within the JSC Photographic Technology Division. Two purely photographic techniques used for specific subject isolation are discussed in detail. Sample imagery is included
Evaluation of film type QX 807 (SO-368, Kodak Ektachrome MS, Estar thin base, with an equivalent Wratten 2A filter overcoat)
A color film with a sensitivity and color balance equal to SO-368, Kodak MS Ektachrome (Estar thin base) was required for use on the Apollo-Soyuz test project (ASTP). A Wratten 2A filter was required for use with the film to reduce short wavelength effects which frequently produce a blue color balance in aerial photographs. The background regarding a special emulsion which was produced with a 2A filter equivalent as an integral part of an SO-368 film manufactured by Eastman Kodak, the cost for production of the special film, and the results of a series of tests made within PTD to certify the film for ASTP use are documented. The tests conducted and documented were physical inspection, process compatibility, effective sensitivity, color balance, cross section analysis, resolution, spectral sensitivity, consistency of results, and picture sample analysis
Water penetration study
Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. An experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included
Energetic solar particle fluxes out to 3 AU during the 7 May 1978 flare event
Simultaneous solar proton flux measurements on IMP 7 and by the world wide neutron monitor network during the May 7, 1978 flare event led to conclusions that in the energy range from 50 MeV to 10 GeV: (1) the propagation of the flare particles in the interplanetary magnetic field (IMF) between the Sun and the Earth was nearly scatter free; and (2) therefore, the intensity time (IT) profiles of the solar proton fluxes observed at Earth for about one hour after onset represent the solar injection profiles even to energies as low as 50 MeV. Observations of the IMF at Helios A indicate that the IMF was undisturbed between the Sun and Helios A at the time of the May 7, 1978 flare event; and, therefore, the solar particle propagation was also scatter free from the Sun to Helios A
Evaluation of S190A radiometric exposure test data
The S190A preflight radiometric exposure test data generated as part of preflight and system test of KM-002 Sequence 29 on flight camera S/N 002 was analyzed. The analysis was to determine camera system transmission using available data which included: (1) films exposed to a calibrated light source subject; (2) filter transmission data; (3) calibrated light source data; (4) density vs. log10 exposure curves for the films; and (5) spectral sensitometric data for the films. The procedure used is outlined, and includes the data and a transmission matrix as a function of field position for nine measured points on each station-film-filter-aperture-shutter speed combination
Investigating the adjacent patient radiation dose received during a simulated ward chest X-ray examination
Introduction: A patient having a chest X-ray will inevitably be exposed to radiation from the primary beam. Using a light beam diaphragm (LBD) on the X-ray tube reduces scattered radiation at the X-ray tube through longitudinal and horizontal collimation. But not scattered secondary radiation resulting from interactions of the primary beam. This study aimed to investigate whether lead protection on simulated hospital ward inpatients (opposite and adjacent to a simulated chest X-ray examination) would change the secondary scattered radiation dose received.
Method: Two rando phantoms (simulated patients) were positioned at different distances from the simulated patient receiving the chest X-ray. The phantoms were positioned one metre adjacent (either side of the phantom being X-rayed) and two metres opposite. The scattered radiation dose to radiosensitive organs (thyroid, breast, and gonads) was recorded using Thermoluminescent Dosimeters (TLDs). Six exposures were conducted, three with lead protection and three without. The mean radiation dose and standard deviation were compared using a paired two-sample t-test for statistical significance (p>0.05).
Results: The lead protection reduced the radiation dose to the radiosensitive organs by 64%-100% (p=0.51-0.18) one metre adjacent and 65%-100% (p=0.65-0.18) two metres opposite. Noticeably the phantom two metres opposite had substantial individual organ dose reductions due to the distance from the primary beam.
Conclusion: Lead aprons, thyroid collars, and distance reduced the radiation dose to the radiosensitive organs of the surrounding phantoms (simulated patients) from an adjacent chest X-ray examination and present opportunities for dose reduction techniques during ward chest X-ray examinations
Rising Buddhism in Vietnam
The religion in Vietnam has come to a turning point. Buddhism has been revived and the people of this country are taking interest in this renewed Buddhism. I visited several of the revitalized Truc Lam Zen monasteries and discussed with monks their current practices. I also read an article that addresses this new phenomenon in Vietnam and criticizes its origination. I interviewed two laity about their experiences and opinions about the rising Buddhism in Vietnam today. I found that there are several factors contributing to this new attraction, particularly in the younger generation. I concluded with agreeing with my last two interviewees that as long as the people of Vietnam are content with their newfound spirituality, its origin is of little consequence
Recommended from our members
Texas Business Review, January 1976
The Business Situation in Texas; The Last Hundred Years; The Next Hundred Years; Electric Funds Transference: Development and Prospects; Texas Construction: Four Decades of ChangeBureau of Business Researc
Recommended from our members
Modeling the observed proton aurora and ionospheric convection responses to changes in the IMF clock angle: 1. Persistence of cusp proton aurora
We employ a numerical model of cusp ion precipitation and proton aurora emission to fit variations of the peak Doppler-shifted Lyman-a intensity observed on 26 November 2000 by the SI-12 channel of the FUV instrument on the IMAGE satellite. The major features of this event appeared in response to two brief swings of the interplanetary magnetic field (IMF) toward a southward orientation. We reproduce the observed spatial distributions of this emission on newly opened field lines by combining the proton emission model with a model of the response of ionospheric convection. The simulations are based on the observed variations of the solar wind proton temperature and concentration and the interplanetary magnetic field clock angle. They also allow for the efficiency, sampling rate, integration time and spatial resolution of the FUV instrument. The good match (correlation coefficient 0.91, significant at the 98% level) between observed and modeled variations confirms the time constant (about 4 min) for the rise and decay of the proton emissions predicted by the model for southward IMF conditions. The implications for the detection of pulsed magnetopause reconnection using proton aurora are discussed for a range of interplanetary conditions
- …