232 Matching Results

Search Results

Advanced search parameters have been applied.

Rapid excavation by rock melting. LASL subterrene program, December 31, 1972--September 1, 1973

Description: Research is continuing on establishing the technical and economic feasibility of excavation systems based upon the rockmelting (Subterrene) concept. A series of electrically powered, small-diameter prototype melting penetrators have been developed and tested. Research activities include optimizing penetrator configurations, designing high-performance heater systems, and improving refractory-metals technology. The properties of the glass linings that are automatically formed on the melted holes are being investigated for a wide variety of rocks and soils. Thermal and fluid-mechanics analyses of the melt flows are being conducted with the objective of optimizing penetraton designs. Initial economic models of the rock-melting concept extended to large tunnelers are being developed. Field tests and demonstrations of the prototype devices continue to be performed in a wide range of rock and soil types. The conceptual design of the electrically powered, self-propelled, remotely guided, horizontal tunnel-alignment prospecting system (Geoprospector) has been initiated. Such a device will also find applications in energy transmission, i.e., utility and pipeline installations. The long-term goal of the research is to develop the technology and prototype hardware that will ultimately lead to large tunneling devices, with improved advance rates and reduced tunnel project costs. The rockmelting concept includes elements that will result in innovative solutions to the three major functional areas of tunneling: rock disintegration, materials handling, and hole-support linings. The proposed excavation method, which is relatively insensitive to variations in rock formation, produces a liquid melt that can be chilled to a glass and formed into a dense, strong, firmly attached hole lining. Unique applications to large automated tunneling systems, ultradeep coring for geoscience research, and hot-rock penetration for geothermal energy development are being investigated, (auth)
Date: November 1, 1973
Creator: Hanold, R. J.
Partner: UNT Libraries Government Documents Department

Bounds for creep in thick spherical pressure vessels

Description: The creep of a hollow sphere subject to constant internal pressure is considered. A method is derived for obtining a priori upper and lower bounds for the displacement of any point in the spherical body at any time. (TFP)
Date: October 1, 1973
Creator: Edelstein, W.S. & Valentin, R.A.
Partner: UNT Libraries Government Documents Department

Pressure vessel reliability as a function of allowable stress

Description: From Winter meeting of American Society of Mechanical Engineers; Detroit, Michigan, USA (11 Nov 1973). The probability of failure corresponding to specified levels of allowable design stress was calculated for pressure vessels designed in accordance with the ASME Boiler and Pressure Vessel Code. The analysis was performed for maximum shear stress failure and for cyclic stress failure. The significance of such failure prediction is ddscussed and a rationale for selecting an allowable stress is presented. Examples are presented that demonstrate the estimation of vessel failure probability as a function of load variation, strength variation, and design safety factor. (auth)
Date: January 1, 1972
Creator: Arnold, H.G.
Partner: UNT Libraries Government Documents Department

19 mm ballistic range: a potpourri of techniques and recipes

Description: The expansion of ballistic gun range facilities at LLL has introduced state-of-the-art diagnostic techniques to glovebox-enclosed ballistic guns systems. These enclosed ballistic ranges are designed for the study of one- dimensional shock phenomena in extremely toxic material such as plutonium. The extension of state-of-the-art phtographic and interferometric diagnostic systems to glovebox-enclosed gun systems introduces new design boundaries and performance criteria on optical and mechanical components. A technique for experimentally evaluating design proposals is illustrated, and several specific examples (such as, target alignment, collateral shrapnel damage, and soft recovery) are discussed. (auth)
Date: September 23, 1975
Creator: Carpluk, G.T.
Partner: UNT Libraries Government Documents Department

Conceptual design of a coring Subterrene Geoprospector

Description: A rock-melting Subterrene system is described that can obtain a continuous core along the projected route of a tunnel. System specifications, individual component functions, preliminary design concepts, and design alternatives are included; and subcomponents that can be assembled from commercially available hardware are indicated. The device requires 150 kW of electric power to melt an accurate 300-mm (1-ft)-dia glass-lined hole and removes a 200-mm (8-in.)-dia glass-cased core at an advance rate of 0.4 mm/s (5 ft/h). The accurate hole diameter and stable hole lining allow the use of a packer- thruster located at the heated holemelting and hole-forming penetrator assembly. An orientation sensor and a guidance unit can also be located in this assembly. A hollow, flexible stem trailing behind the assembly contains the electric-power, coolant, and instrumentation lines, and provides a passage for debris removal. Core sections are removed through the flexible stem intermittently with wire-line core-retrieval hardware. This Subterrene system, named Geoprospector, is essentially a self-propelled and surface-guided minitunneler. It is a logical major development step in the Subterrene prograrm, directed toward a larger- diameter tunneling machine. Other practical Geoprospector applications are the forming of holes under obstacles such as rivers, highways, buildings, or other structures to accommodate utility lines or cables; the implantation of urban utilities; and the installation of underground pipelines or power-transmission lines without ditching. (auth)
Date: February 1, 1974
Creator: Neudecker, J.W.
Partner: UNT Libraries Government Documents Department

Failure of cooling tower LOB-CT-1

Description: Following the loss of cooling tower LOB-CT-1, an investigation was conducted to determine the cause and to develop precautions to prevent future cooling tower losses. This cooling tower, located in the office-building basement of the Clinton P. Anderson Los Alamos Meson Physics Facility (LAMPF), was shut down on October 29, 1973. Excessive use of chelate chemical was ludged to be the major factor involved in the high corrosion rates observed. A number of precautions are listed which should prevent further surprise'' corrosion problems. The precautions include precalculation of chemical additions, visual inspection, corrosion coupons, corrosion meters, and chemical analyses of operating conditions. (auth)
Date: March 1, 1974
Creator: Midkiff, W.S.
Partner: UNT Libraries Government Documents Department

Some aspects of micro-drill technology

Description: Providing research equipment for the many and varied projects at Lawrence Livermore Laboratory leads to interesting machining requirements. One of these is the need to drill very small holes, and in a variety of materials. Holes down to 0.001 in. in dia, approximately 12 dia deep, in brass, steel, stainless steel, copper, gold, plastics, uranium, etc., are not uncommon. This paper discusses methods of sharpening microdrills down to .001 in. in dia and some results obtained with their use. (TFD)
Date: September 1, 1974
Creator: Ellers, R.C. & Spies, R.J.
Partner: UNT Libraries Government Documents Department