Rotational Remanent Magnetization (RRM) occurs when ferromagnetic rock specimens are AF demagnetized while rotating slowly. An extensive study of the properties of this remanence has been made in an attempt to determine its formation mechanism. Experiments on good conductors and soft magnetic materials rotating in steady magnetic fields show no corresponding magnetic effects. It is also shown that RRM is not an inertial effect and cannot be produced during thermal magnetization. A comparison of the AF demagnetization curves of RRM with those of other remanences is described, which shows that RRM differs from ARM. RRM has now been confirmed in three different laboratories.

Since many engineering projects in rock never mobilize strengths near the uniaxial compressive strength (UCS) of the rock, elastic modulus becomes a critical parameter to describe the rock's behavior under loading. There are a number of methods available for calculating the elastic modulus from laboratory test data, and each method gives a slightly different value. The objective of this study is to evaluate the most repeatable method for each of a number of rock types, and then to develop guidelines to aid the practitioner in selecting the best method as a function of rock behavior. UCS tests were performed on 78 samples of nine rock types, including two basalts, two granites, two limestones, a quartzite, a sandstone, and a gypsum. Elastic moduli were calculated using six different methods reported in the literature or modified for this study. The modified secant and modified secant-at-50-percent-strength moduli (modified by shifting the origin to best intercept the extension of the main straight-line portion of the stress-strain curve) were the most repeatable methods for rocks with elastic and plastic-elastic behavior. Elastic-plastic materials, which have a broad concave-downward stress-strain curve, are best evaluated using the tangent modulus on the upper of two distinct straight-line segments. For materials which show creep or extended plastic deformation with no sharp failure, the secant-at-50-percent-strength modulus and modified secant-at-50-percent-strength modulus are the most repeatable.

V APOR -LIQUID equilibria were determined for the azeotropic binary system 2,4-dimethylpentane-benzene at 760, 400, and 250 mm. Hg pressure. Vapor-liquid equilibria were then determined at 400 mm. Hg pressure for the three ternary systems: the hydrocarbon binary system plus each of three polar solvents-hexylene glycol, aniline, and furfural. The main purpose of the study was to observe and correlate the effects of these extractive solvents on the hydrocarbon relative volatility. A Colburn vapor recirculating equilibrium still was used. All analyses were performed on a Beckman model GC-2 chromatograph. The error in the equilibrium determinations was less than 1%. The maximum temperature range experienced in this study, 36°C ., was with hexylene glycol as the solvent. CHEMICALS USEDThree hydrocarbons were used in this study: 2,4 dimethylpentane (2,4 DMP), benzene, and methylcyclohexane (MCH). The MCH was used in the analysis procedure. All three hydrocarbons were obtained (Phillips Petroleum Co.) as pure grade chemicals (guaranteed 99.0 mole % minimum purity). All of these hydrocarbons were eluted on the chromatograph at 70°C .; they were all of approximately 99.5 mole % purity as determined by the chromatograms. These hydrocarbons were used without further purification.

No abstract

No abstract