Bibliography of terrestrial impact structures

This bibliography lists 105 terrestrial impact structures, of which 12 are proven structures, that is, structures associated with meteorites, and 93 are probable. Of the 93 probable structures, 18 are known to contain rocks with meteoritic components or to be enriched in meteoritic signature-elements, both of which enhance their probability of having originated by impact. Many of the structures investigated in the USSR to date are subsurface features that are completely or partly buried by sedimentary rocks. At least 16 buried impact structures have already been identified in North America and Europe. No proven nor probable submarine impact structure rising above the ocean floor is presently known; none has been found in Antarctica or Greenland. An attempt has been made to cite for each impact structure all literature published prior to mid-1983. The structures are presented in alphabetical order by continent, and their geographic distribution is indicated on a sketch map of each continent in which they occur. They are also listed tables in: (1) alphabetical order, (2) order of increasing latitude, (3) order of decreasing diameter, and (4) order of increasing geologic age

Effectifs des diverses sequences de polyedres 3-valents convexes ayant moins de 11 faces et de polyedres sans face triangulaire ayant de 11 a 14 faces

AbstractA table is presented of various sequences of 3-valent convex polyhedra, a sequence being defined by p3p4⋯⋯⋯pi⋯⋯⋯ where pi is the number of faces with i edges. These sequences are given for polyhedra with 6, 7, 8, 9, 10 faces and the sequences where p3=0 are given for polyhedra having 11, 12, 13, 14 faces. The number of polyhedra is also given for each sequence

On the Physical Meaning of the Isothermal Titration Calorimetry Measurements in Calorimeters with Full Cells

We have performed a detailed study of the thermodynamics of the titration process in an isothermal titration calorimeter with full cells. We show that the relationship between the enthalpy and the heat measured is better described in terms of the equation Δ H = Winj + Q (where Winj is the work necessary to carry out the titration) than in terms of ΔH = Q. Moreover, we show that the heat of interaction between two components is related to the partial enthalpy of interaction at infinite dilution of the titrant component, as well as to its partial volume of interaction at infinite dilution

Preparation of a geologic photo map and hydrologic study of the Yemen Arab Republic

There are no author-identified significant results in this report

Isothermal Crystallization Kinetics of In Situ Photo and Thermo Aged Poly(Ethylene Oxide) Using PhotoDSC

Isothermal crystallization of a high molecular weight PEO (Mw= 4.000.000) has been investigated using photoDSC. Combining light irradiation, heating and DSC analysis, photoDSC demonstrates a good capability to follow the in situ photo and thermo aging of semi crystalline polymers. Isothermal crystallization of PEO has been performed at 55°C. After aging at different temperatures ranging from 0 to 90°C and for various periods of time, the kinetics of this crystallization has been found fitting Avrami theory. Avrami exponent, n, was found between 0.9 and 1.4 revealing a one-dimensional growth process. It was also found that isothermal crystallization rate (i.e. reciprocal crystallization half-time) was time exposure, aging temperature and light intensity dependent which makes this kinetics parameter a good indicator to follow and to compare the degradation of the semi-crystalline polymers

Crystallization of carbon tetrachloride in confined geometries

International audienceThe thermal behaviour of carbon tetrachloride confined in silica gels of different porosity was studied by differential Scanning Calorimetry. Both the melting and the phase transition at low temperature were measured and found to be inextricably dependant upon the degree of confinement. The amount of solvent was varied through two sets of experiments, sequential addition and original progressive evaporation allowing the measurement of the DSC signals for the various transitions as a function of the amount of CCl4. These experiments allowed the determination of transition enthalpies in the confined state which in turn allowed the determination of the exact quantities of solvent undergoing the transitions. A clear correlation was found between the amounts of solvent undergoing the two transitions (both free and confined) demonstrating that the formation of the adsorbed layer t does not interfere with the second transition. The thickness of this layer and the porous volumes of the two silica samples were measured and found to be in very close agreement with the values determined by gas sorption

Polymer Microstructures. Modification and Characterisation by Fluid Sorption

International audiencePolymer micro-organisation can be modified by combination of the three constraints, thermal, hydrostatic and fluid sorption. In selecting the fluid's nature, chemically active or inert, and its physical state, liquid or supercritical, new “materials” can be generated. In addition, the interplay of temperature and pressure allows tailoring the obtained material structure for specific applications. Several complementary techniques have been developed to modify, analyze and characterize the end products: scanning transitiometry, vibrating wire (VW)-PVT coupling, thermoporosimetry, temperature modulated DSC (TMDSC), sorptometry. The great variety of possible applications in materials science is illustrated with different polymers which can produce materials from soft gel to rigid foams when submitted to fluid sorption, typical fluids being methane, or a simple gas (CO2 or N2). Absorption of an appropriate fluid in a cross linked polymer leads to a swelling phenomenon. Thermoporosimetry is a calorimetric technique developed to measure the shift by confinement of thermal transition temperatures of the swelling fluids, which can be currently used solvents or mercury. Application of thermoporosimetry to a swollen cross linked polymer allows to calculate the mesh size distribution and to evaluate the degree of reticulation of the polymer. The same technique can be applied to characterise the pore size distribution in a foamed polymer

Determination of Thermodynamic Partial Properties in Multicomponent Systems by Titration Techniques

Thermodynamic experimental techniques using titration are usually employed to study the interaction between solutes in a diluted solution. This chapter deals with the underlying thermodynamic framework when titration technique is applied with densimetry, sound speed measurement and isothermal titration calorimetry. In the case of partial volumes and partial adiabatic compressibilities, a physical interpretation is proposed based upon atomic, free volume and hydration contributions