Search

Shock compression of the materials of planetary interiors yields data which upon comparison with density-pressure and density-sound velocity profiles constrain internal composition and temperature. Other important applications of shock wave data and related properties are found in the impact mechanics of terrestrial planets and solid satellites. Shock wave equation of state, shock-induced dynamic yielding and phase transitions, and shock temperature are discussed. In regions where a substantial phase change in the material does not occur, the relationship between the particle velocity, U(sub p), and the shock velocity, U(sub s), is given by U(sub s) = C(sub 0) + S U(sub p), where C(sub 0) is the shock velocity at infinitesimally small particle velocity, or the ambient pressure bulk sound velocity. Numerical values for the shock wave equation of state for minerals and related materials of the solar system are provided.

We assayed 100 capillary whole blood specimens from 50 adults on the Precision QID blood glucose testing system (MediSense, Waltham, Mass) and in duplicate on a whole blood reference method. We centrifuged aliquots of each specimen and analyzed the resulting plasma in the clinical laboratory. The Precision QID achieved maximum total error of 15.5% at a glucose concentration of 42 mg/dL, 12.3% at 83 mg/dL, and 6.4% at 280 mg/dL. The amount of error demonstrated satisfies the performance requirement established by the 1986 Conference on Self-Monitoring of Blood Gluco

In New Jersey and throughout the country, the new Municipal Stormwater Regulation Program will require significant changes in the way stormwater infrastructure is managed. Digital mapping can offer a variety of solutions to make this process easier. A digital map allows the user to manage multiple sheets in a single electronic file, and to retrieve the necessary mapping information in a matter of seconds. By taking digital maps to the next level with Geographic Information System (GIS) technology, it is also possible to add other critical data right to the map itself. Whereas a digital map will allow the user to view the location of a stormwater drainage pipe in relation to its surroundings, GIS technology will allow the user to view tables of information about the same stormwater drainage pipe with a simple click of the mouse. Entire infrastructure systems, as well as Stormwater Management Plans and Stormwater Pollution Prevention Plans can be mapped, and a wide variety of related data can be organized and managed with GIS. The zoning and land use aspects associated with good stormwater management and water quality improvement practices can also be tracked with GIS. For example, by performing a build-out analysis, it is possible to study the impact of future growth and development on a municipality or region. By analyzing the “what-if” factors of additional impervious surfaces, potable water needs, and even pollution from additional automobiles now, it will be possible to utilize Smart Growth and related initiatives to prevent environmental damage before it occurs, rather than trying to deal with its impact later on. GIS can also assist with the public education initiatives needed to make these changes seem both positive and possible.

We heated mixtures of sulfur and Na-bearing silicates in evacuated silica glass capsules to temperatures between 600°C and 950°C. At or above 850°C, Na-silicate glass reacts with elemental S to form a (Na,K) sulfide. Mobilization of this phase may account for the presence of Na and K on the surface of Io, and hence in the material sputtered into the Jovian magnetosphere.

C 2 and other small molecules produced during shock-induced (24–63 GPa) decomposition of liquid benzene (initially at 1 bar at 295 K) have been detected by time-resolved (50–120 ns) spectroscopy. These molecular products have been identified by characteristic electronic bands observed together with a gray-body background in visible and near-ultraviolet shock-induced chemiluminescence spectra collected during the passage of the shock front through the focus of spectrographs equipped with gated, intensified diode-array detectors. The spectroscopic techniques are described, and the dependence of the spectra on shock parameters will be discussed in terms of known decomposition mechanisms of highly excited benzene molecules.

Tetrahedrites of composition (Cu, Ag)10(Cu2, Fe, Zn)2(Sb, As)4S13 or Cu12Sb14/3S13 have 208 valence electrons per unit cell and are expected to be semiconductors. The bands are full in these cases, whereas compositions towards the classical formula Cu12Sb4S13 (204 valence electrons per unit cell) have only partially filled bands and are therefore expected to be metallic. These predictions are supported by new optical absorption spectra of tetrahedrites with 205 and 208 valence electrons per unit cell. The gap between valence and conduction bands of the semiconductor is about 1.7 (±0.2) eV. A further prediction based on a nearly-free electron model is that 208 valence electrons per unit cell represent a compositional limit for tetrahedrites, and that the stability increases as compositions approach this limit. Existing data indicate an exponential increase in the number of occurrences as the limit is approached.

Benzene decomposes when shocked to pressures greater than 13 GPa. However, few products of the decomposition reactions have been identified in situ or by recovery methods. This paper reports the detection by time-resolved (50-to-120 nsec) chemiluminescence spectroscopy of excited molecular products of the decomposition of benzene at pressures from 24 to 63 GPa. Strong spectral bands characteristic of C2 are readily identified among other features and a gray-body background. The dependence of the spectra on shock parameters are breifly discussed in terms of known decomposition mechanisms of highly excited benzene.

This paper describes the status of our diamond-anvil cell experiments of the NH3-H2O P-T-X phase diagram. Two parts of the diagram are discussed: the isothermal P-X diagram of (NH3)x(H2O)1-x for 0 ≤ X ≤ 0.3 and the melting line of (NH3)0.5(H2O)0.5. Five phases were observed, including: the liquid; ice VI and ice VII (which resembled their descriptions in the literature); a high-relief apparently isotropic ammonia monohydrate phase; and a low-relief, strongly anisotropic ammonia dihydrate phase. Our interpretation of the isothermal P-X diagram has been modified by recognition that difficulty in nucleating ice VI had led us to underestimate the importance of the ice VI plus liquid and ice VI plus ammonia dihydrate fields. Some unresolved questions and directions for future studies are discussed.

A Holzapfel-type diamond anvil cell is used to determine the NH3 - H2O phase diagram in the region from 0 to 33 mole percent NH3, 240 to 370 K, and 0 to 5 GPa. The following phases were identified: liquid; water ices Ih, III, V, VI, VII, and VIII; ammonia monohydrate, NH3.H2O; and ammonia dihydrate NH3.2H2O. Ammonia dihydrate becomes prominent at moderate pressures (less than 1 GPa), with planetologically significant implications, including the possibility of layering in Titan's magma ocean.