3,053 research outputs found
The albedo of particles in reflection nebulae
The relation between the apparent angular extent of a reflection nebula and the apparent magnitude of its illuminating star was reconsidered under a less restrictive set of assumptions. A computational technique was developed which permits the use of fits to the observed m-log a values to determine the albedo of particles composing reflection nebulae, providing only that a phase function and average optical thickness are assumed. Multiple scattering, anisotropic phase functions, and illumination by the general star field are considered, and the albedo of reflection nebular particles appears to be the same as that for interstellar particles in general. The possibility of continuous fluorescence contributions to the surface brightness is also considered
Research Studies in Religious Education
The Lutheran Education Association assumed the task of compiling a bibliography of research studies in religious education to fill the need for such a catalogue. The bibliography, consisting of classified abstracts with index, was compiled especially with the needs of educators of The Lutheran Church--Missouri Synod in mind. It should be suggestive for future research studies in religious education and should serve to prevent duplication of effort as well as to suggest areas of study not previously covered or covered inadequately
Using Manipulatives to Teach Beginning Reading Skills
Based on a review of the literature, a reading curriculum for kindergarten children was created. The curriculum focuses on the learning of beginning reading skills through hands-on manipulative activities. The activities were arranged into ten centers. Each center related to beginning reading skills. Each activity is self-correcting and requires minimal verbal directions from the teacher
Analysis of SPAR 8 single-axis levitation experiment
The melting and resolidification of SPAR 8 payload melting and resolidification of a glass specimen from the in a containerless condition and the retrieval and examination of the specimen from the. The absence of container contact was assured by use of a single-axis acoustic levitation system. However, the sample contacted a wire cage after being held without container contact by the acoustic field for only approximately 87 seconds. At this time, the sample was still molten and, therefore, flowed aroung the wire and continued to adhere to it. An analysis of why the sample did not remain levitated free of container contact is presented. The experiment is described, and experimental observations are discussed and analyzed
Grain-refining heat treatments to improve cryogenic toughness of high-strength steels
The development of two high Reynolds number wind tunnels at NASA Langley Research Center which operate at cryogenic temperatures with high dynamic pressures has imposed severe requirements on materials for model construction. Existing commercial high strength steels lack sufficient toughness to permit their safe use at temperatures approaching that of liquid nitrogen (-320 F). Therefore, a program to improve the cryogenic toughness of commercial high strength steels was conducted. Significant improvement in the cryogenic toughness of commercial high strength martensitic and maraging steels was demonstrated through the use of grain refining heat treatments. Charpy impact strength at -320 F was increased by 50 to 180 percent for the various alloys without significant loss in tensile strength. The grain sizes of the 9 percent Ni-Co alloys and 200 grade maraging steels were reduced to 1/10 of the original size or smaller, with the added benefit of improved machinability. This grain refining technique should permit these alloys with ultimate strengths of 220 to 270 ksi to receive consideration for cryogenic service
The surface brightness of reflection nebulae
Hubble's equation relating the maximum apparent angular extent of a reflection nebula to the apparent magnitude of the illuminating star has been reconsidered under a set of less restrictive assumptions. A computational technique is developed which permits the use of fits to observed m, log a values to determine the albedo of the particles composing reflection nebulae, providing only that one assumes a particular phase function. Despite the fact that all orders of scattering, anisotropic phase functions, and illumination by the general stellar field are considered, the albedo which is determined for reflection nebulae by this method appears larger than that for interstellar particles in general. The possibility that the higher surface brightness might be due to a continuous fluorescence mechanism is considered both theoretically and observationally
Initial investigation of cryogenic wind tunnel model filler materials
Various filler materials are being investigated for applicability to cryogenic wind tunnel models. The filler materials will be used to fill surface grooves, holes and flaws. The severe test environment of cryogenic models precludes usage of filler materials used on conventional wind tunnel models. Coefficients of thermal expansion, finishing characteristics, adhesion and stability of several candidate filler materials were examined. Promising filler materials are identified
A search for continuous fluorescence in reflection nebulae
Photometric and spectrophotometric observations were made of the reflection nebulae NGC1435, NGC2068, NGC7023, and IC1287 in an attempt to detect continuous fluorescence by dust grains. Several effects of importance for observations of such faint objects are discussed, including instrumental light scattering, a photographic effect, and a time delay effect which can occur if the illuminating star is a spectrum variable. It is found that continuous fluorescence by interstellar grains is not likely to exist and that it cannot account for more than 10 percent of the total surface brightness of these reflection nebulae. No evidence of diffuse interstellar features is found in the spectra of these nebulae
Ground-water appraisal of the Meadow Valley area, Lincoln and Clark Counties, Nevada
This report, the 27th in the series of reconnaissance ground-water studies which were initiated following authorization by the I960 Legislature, gives the results of a study of the Meadow Valley area. This area includes eight valleys in southeastern Nevada - - Patterson, Spring, Eagle, Dry, Rose, Panaca, Clover, and Lower Meadow Valley - - all part of the Colorado River drainage system.
This study was made and report prepared by F. Eugene Rush, Geologist for the U. S. Geological Survey.
These reconnaissance ground-water resources surveys make available pertinent information of great and immediate value to many State and Federal agencies. As development takes place in any area, demands for more detailed information will arise and studies to supply such information will be undertaken. In the meantime, these reconnaissance type studies are timely and adequately meet the immediate needs for information on the ground-water resources of the areas covered by the reports
Narcotic administration and fall-related injury in the hospital: Implications for patient safety programs and providers
Objective: Identify factors that predict fall-related injury in hospitalized adults. Design: Retrospective cohort study. Setting: 435-bed university hospital. Participants: Inpatients with reported falls in 2010. Results: Medical records were available for 286/293 (98%) of reported falls in 251 patients. 25% (63/286) of falls were associated with injury, 4% (11/286) with serious injury. Compared to all fallers, patients with injury did not differ by gender or age. In univariate analysis, patients who reported hitting their head, had pre-fall confusion, or who received narcotics within 24 hours before falling were more likely to suffer injury (estimated odds ratios 6.04, 2.00 and 5.1, respectfully). In multivariate analysis, receiving a narcotic prior to falling was the strongest predictor of injury (estimated odds ratio 5.59; 95% confidence intervals 2.14 — 14.65, p \u3c0.001). Conclusions: In this single-institution study, 25% of patients who fell suffered injury and 4% serious injury. Neither age nor gender predicted fall-related injury. Recent narcotic administration was the strongest predictor of injury. Strategies to prevent fall-related injury in the hospital should target patients receiving narcotics. When evaluating inpatients who have fallen, providers should be especially vigilant about injury in patients who have pre-fall confusion, hit their head, or have received recent narcotics
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