Technical Report Archive and Image Library (TRAIL) - 22,235 Matching Results

Search Results

An altitude chamber for the study and calibration of aeronautical instruments

Description: The design and construction of an altitude chamber, in which both pressure and temperature can be varied independently, was carried out by the NACA at the Langley Memorial Aeronautical Laboratory for the purpose of studying the effects of temperature and pressure on aeronautical research instruments. Temperatures from +20c to -50c are obtained by the expansion of CO2from standard containers. The chamber can be used for the calibration of research instruments under altitude conditions simulating those up to 45,000 feet. Results obtained with this chamber have a direct application in the design and calibration of instruments used in free flight research.
Date: November 1925
Creator: Reid, J E & Kirchner, Otto E
Partner: UNT Libraries Government Documents Department

Effects of Sanitary Sewers on Ground-Water Levels and Streams in Nassau and Suffolk Counties, New York, Part 1: Geohydrology, Modeling Strategy, and Regional Evaluation

Description: From purpose and scope: This report is the first in a three-part series describing the U.S. Geological Survey's efforts in the detailed hydrologic investigation of southern Nassau and southwest Suffolk Counties, which includes a ground-water modeling study to predict the effects of an extensive sewer network scheduled to be completed in 1985. As the introduction to the series, this report has four objectives: (1) to present a detailed description of the hydrologic system in the area, including newly acquired hydrogeologic information; (2) to define the hydrogeologic factors that will be affected by the sewer network; (3) to explain the modeling strategy and describe the techniques used to develop the ground-water models of the two adjacent areas studied; and (4) to present a preliminary evaluation of the effects of sewers as predicted by a regional ground-water flow model.
Date: 1983
Creator: Reilly, Thomas E.; Buxton, Herbert T.; Franke, O. L. & Wait, R. L.
Partner: UNT Libraries Government Documents Department

Chemical Alteration of Limestone and Marble Samples Exposed to Acid Rain and Weathering in the Eastern United States, 1984-1988

Description: In a long-term program that began in 1984, limestone and marble briquettes have been exposed to both anthropogenic acid deposition and natural weathering at four field sites in the eastern United States. Similar tests began at an Ohio site in 1986. Effects of exposure on the briquettes and other materials at the sites are evaluated periodically by several federal agencies cooperating in the National Acid Precipitation Assessment Program (NAPAP). Wet chemical analysis was used to detect sulfates, nitrates, fluorides, chlorides, and a series of metal cations in sequential layers of stone removed from the briquettes after field exposure. Results from the first four years of the program indicate that rinsing by rain keeps skyward-facing stone relatively clean of reaction products, especially sulfate, the most abundant product.
Date: June 1991
Creator: Reimann, K. J.
Partner: UNT Libraries Government Documents Department

Weight Losses of Marble and Limestone Briquettes Exposed to Outdoor Environment in the Eastern United States: Results of Exposure 1988-1992

Description: Monitoring continued on weight changes in marble and limestone briquettes exposed to the outdoor environment at sites in the eastern US. This report presents data for the exposure period 1988 - 1992 and summarizes results for the entire period from 1984. Since 1989, only three exposure sites have remained active, but briquettes from pre-exposed material were added at those sites. A linear relationship was found between cumulative gravimetric losses and exposure period. These losses resulted in an average recession rate of 11 to 21 micrometers/yr for marble and 21 to 45 micrometers/yr for limestone. The recession rates are site-dependent and can be described with respect to rain depth and other atmospheric conditions, as evidenced by the very low rates at the Ohio site on the movable rack, dry regime. Weight monitoring is continuing in a planned 10-year program.
Date: April 1995
Creator: Reimann, K. J.
Partner: UNT Libraries Government Documents Department

Weight Losses of Marble and Limestone Briquettes Exposed to Outdoor Environments in the Eastern United States : Results of Exposures, 1984-1988

Description: Gravimetric changes in marble and limestone briquettes exposed to outdoor environment at five sites in the eastern United States have been monitored since 1984. An earlier report describes procedures and results obtained in 1984--1988. This report presents the results of the exposure period 1984--1988 and reviews and summarizes those of prior years. A linear relationship was found between cumulative gravimetric losses and exposure period or rain depth. These losses resulted in an average recession rate of 14 to 24 {mu}m/yr for marble and twice that for limestone. Variations in recession among the various exposure sites can be ascribed to differences in rain depth and hydrogen ion concentration. The annual recession rates obtained from gravimetry yielded rates that were for marble twice those obtained from runoff experiments, and more than three times those for limestone; this indicates that physical erosion plays an important role. Gravimetric monitoring of exposed briquettes is continuing in a planned 10-yr program.
Date: September 1991
Creator: Reimann, K. J.
Partner: UNT Libraries Government Documents Department

Reconnaissance of Henry Mountains Area, Wayne and Garfield Counties, Utah

Description: From introduction: A trip into the Henry Mountains area occupied the days from March 6 to 9, 1951, inclusive, excepting March 7, which was used to examine Reo Hunt's deposit in Poison Spring Wash. Observations were made on stratigraphy, regional geology, and the locations of the known deposits of uranium and vanadium.
Date: April 5, 1951
Creator: Reinhardt, E. V.
Partner: UNT Libraries Government Documents Department

Uranium-Copper Deposits Near Copper Canyon Navajo Indian Reservation, Arizona

Description: From introduction: During the summer of 1951, Navajos conducted John W. Chester, Russell C. Cutter, and E. V. Reinhardt, Grand Junction Exploration Branch, U. S. Atomic Energy Commission, to a copper deposit in Copper Canyon. Little radioactivity was noted, and no further work was done in the area at that time. In October 1951, the same group of Navajos reported the discovery of uranium ore in another portion of the same area. The site was visited by Cutter who noted that an excavation made by the Navajos had disclosed a 3-foot thickness of low-grade uranium ore. In November 1951, Cutter again visited the area and observed that the Navajos had opened a 5-foot face of good ore.
Date: March 13, 1952
Creator: Reinhardt, E. V.
Partner: UNT Libraries Government Documents Department

The Distribution of Uranium-Vanadium Deposits in the Colorado Plateau Relative to Tertiary Intrusive Masses

Description: Introduction: Studies of uranium-vanadium occurrences in the Four Corners region show that, with the exception of the Lukachuai area, all of the major deposits in the Morrison formation are grouped around the various igneous masses which are scattered irregularly throughout the Colorado Plateau. The pattern of deposition varies from mountain group to mountain group and each will be described separately. Maps accompany this report to supplement the descriptions of ore occurrences in the vicinity of the La Sal, Abajo, Carrizo, and Henry mountains. Elsewhere, it is believed that a written description will suffice.
Date: June 11, 1952
Creator: Reinhardt, Elmer V.
Partner: UNT Libraries Government Documents Department

Comparison of mechanical properties of flat sheets, molded shapes, and postformed shapes of cotton-fabric phenolic laminates

Description: Report presenting testing to determine the properties of several untreated commercial cotton-fabric pheonlic sheet laminates, the same sheets after exposure to a postforming heating cycle, industrially postformed shapes made from those materials, industrially molded and laboratory-molded shapes, and flat panels postformed in the laboratory from the laboratory-molded shapes. Results regarding tensile properties, flexural properties, and water absorption are provided.
Date: January 1957
Creator: Reinhart, F. W.; Good, C. L.; Turner, P. S. & Wolock, I.
Partner: UNT Libraries Government Documents Department

Calculation of Centrally Loaded Thin-Walled Columns Above the Buckling Limit

Description: When thin-walled columns formed from flanged sheet, such as used in airplane construction, are subjected to axial load, their behavior at failure varies according to the slenderness ratio. On long columns the axis deflects laterally while the cross section form is maintained; buckling results. The respective breaking load in the elastic range is computed by Euler's formula and for the plastic range by the Engesser- Karman formula. Its magnitude is essentially dependent upon the length. On intermediate length columns, especially where open sections are concerned, the cross section is distorted while the cross section form is preserved; twisting failure results. The buckling load in twisting is calculated according to Wagner and Kappus. On short columns the straight walls of low-bending resistance that form the column are deflected at the same time that the cross section form changes - buckling occurs without immediate failure. Then the buckling load of the total section computable from the buckling loads of the section walls is not the ultimate load; quite often, especially on thin-walled sections, it lies considerably higher and is secured by tests. Both loads, the buckling and the ultimate load are only in a small measure dependent upon length. The present report is an attempt to theoretically investigate the behavior of such short, thin-walled columns above the buckling load with the conventional calculating methods.
Date: April 1945
Creator: Reinitzhuber, F.
Partner: UNT Libraries Government Documents Department

Stresses in single-spar wing constructions with incompletely built-up ribs

Description: It is shown that the force distribution resulting from incomplete ribs in single spar wing structures may be determined with the aid of the shear field method by a statistically indeterminate computation. A numerical computation is given of the force distribution of a wing structure whose two neighboring incomplete ribs with web missing in half the section are torsionally loaded.
Date: March 1940
Creator: Reinitzhuber, F.
Partner: UNT Libraries Government Documents Department

An analysis of the fatigue life of an airplane wing structure under overload conditions

Description: From Introduction: "Fatigue life expectancy in normal transport operations was investigated in reference 1 and was found to be of equal importance with single-gust life. The effect of overload operation of transport airplanes on the probability of encountering single critical gusts was investigated in reference 2 and the frequency of critical gusts was found to increase rapidly with overload. The effect of overload operation on fatigue strength, however, has not heretofore been evaluated, hence the investigations of references 1 and 2 are combined herein to permit such evaluation and to determine the relative importance of fatigue and single-gust failures under conditions of overload operation."
Date: February 1946
Creator: Reisert, Thomas D
Partner: UNT Libraries Government Documents Department

Gust-tunnel investigation to determine effects of center-of-gravity position on the gust loads of a delta-wing model with leading edge swept back 60 degrees

Description: Report presenting an investigation to determine the effects of center-of-gravity position on the gust loads of a delta-wing model with the leading edge swept back 60 degrees. A 15-percent change in the center-of-gravity position on the mean geometric chord produced a 7.5-percent change in load for the model in a sharp-edge gust and a 35-percent change in load in a gust with a 6.5 chord gradient distance.
Date: June 5, 1953
Creator: Reisert, Thomas D. & Maglieri, Domenic J.
Partner: UNT Libraries Government Documents Department