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Pressure-volume, uniaxial stress loading to failure, uniaxial strain, and acoustic velocity determinations were made on Blair dolomite at confining pressures ranging to 3.5 GPa (Pa = Paschals where 10/sup 5/ Pa = 1 bar or 0.1 GPa = 1 kbar). The bulk modulus K, rapidly rises from an initial 10.4 GPa (at atmospheric pressure) to 102.0 GPa at 1 GPa pressure. At higher pressures, K remains essentially constant (110 GPa). The maximum volume change on loading is 3.9% at 3.5 GPa; the unloading closely follows the loading path. Comparison of uninxial stress tests in compression to 0.7 GPa and extension to 2.1 GPa confining pressure demonstrates that the characteristic shear stress at failure as well as the transition from brittle fracture to ductile flow is strongly dependent upon both the value of the intermediate principal stress sigma /sub 2/ and the rate of strain. The onset of dilatancy as determined in uniaxial compression occurs at about two-thirds of the failure stress. The uniaxial strain loading path is well below the failure envelope in compression. In uniaxial stress loading (compression), Young' s modulus (E) and shear modulus ( mu ) are demonstrated to be very sensitive to both confining pressure and …

The mechanical properties of tuff from instrument hole UG3, tunnel U12e.06 at the Nevada Test Site have been investigated to 1400 MPa, The shear strength increases from about 5 MHa unconfined to 12 MPa at 300 MPa mean pressure. A brittle-ductile transition was indicated at about 250 MPa. In uniaxial strain, the sample loads to the vicinity of the failure envelope and then is parallel to that envelope up to the highest stresses, 420 MPa. Hydrostatic pressure of 1400 MPa produces about 9% volume compression and 1.3% permanent compaction in this apparently saturated tuff. (auth)

It was demonstrated that a transient surface-current pulse can be sensed and recorded by a graded-Hc film, a magnetic film with the coercive force Hc varying along the length of the film. Information on the magnitude of the current can be obtained by comparing the domain-wall location with the distribution of Hc value along the film. The transient characteristic of the current pulse can be deduced from the V-shaped configuration of the domain wall. (auth)

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A failure analysis was conducted on an aluminum (5083) structure subjected to fatigue testing. Failure occurred by fatigue in an electron-beam weld; the cycles to failure were reasonable for the loading conditions. (5 figures) (auth)

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Guide for attempting to design, conduct and analyse x-ray laser experiments.

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Engineering information is provided to fabricate and operate equipment for generating hollow cathode arcs. Topics include equipment selection and design, operating procedures, and operating characteristics. Hollow-cathode operating characteristics for a wide range of cathode sizes, gas-flow rates, gas types, and cathode-anode spacings are covered. (auth)

From 3rd international congress of the International Radiation Protection Association meeting; Washington, District of Columbia, USA(9 Sep 1973). Between 1967 and 1972, eighteen second generation'' lightwater-cooled nuclear power plants, with capacities in the range of 500 to 800 MW(e) have been put into operation in the United States. These were in addition to ten smaller demonstration plants and one high-temperature gas-cooled nuclear power plant in operation at the start of this period. The reported yearly air effluent releases of radioactive gases, halogens and particulates, and liquid effluent fission and activation products and of tritium from these plants are evaluated on a Ci/10/sup 3/ MW(e) basis, and the overall yearly averages for the various types of reactors (boiling water (BWR), pressurized water (PWR) and high temperature gas-cooled (HTGR)! are compared. These and the amounts of effluents released from reference 1,000 MW(e) fossil-fueled plants are compared in terms of relative environmental concentrations and their relationship to the applicable U. S. environmental standards for the principal constituents in their respective plant air-effluent streams. 21 references. (auth)

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