Observations of the north polar region of Mars from the Mars orbiter laser altimeter

Elevations from the Mars Orbiter Laser Altimeter (MOLA) have been used to construct a precise topographic map of the martian north polar region. The northern ice cap has a maximum elevation of 3 kilometers above its surroundings but lies within a 5-kilometer-deep hemispheric depression that is contiguous with the area into which most outflow channels emptied. Polar cap topography displays evidence of modification by ablation, flow, and wind and is consistent with a primarily H2O composition. Correlation of topography with images suggests that the cap was more spatially extensive in the past. The cap volume of 1.2 x 10(6) to 1.7 x 10(6) cubic kilometers is about half that of the Greenland ice cap. Clouds observed over the polar cap are likely composed of CO2 that condensed out of the atmosphere during northern hemisphere winter. Many clouds exhibit dynamical structure likely caused by the interaction of propagating wave fronts with surface topography.     

Family functioning in bipolar I disorder.

In a sample of 62 patients with Bipolar I disorder, the authors used a repeated measures longitudinal design to examine whether global family functioning was associated with the presence of a concurrent bipolar episode as well as whether global family functioning was associated with the presence of manic and depressive episodes in the following 3 months. Participants were recruited for a randomized clinical trial examining the efficacy of family treatments combined with pharmacotherapy for bipolar disorder. Global family functioning was repeatedly measured with both clinician-rated and patient-rated assessment instruments over the 28-month study period. Results indicated that mood episodes were associated with concurrent global family functioning within individuals, but global family functioning was not associated with episode status in the subsequent 3 months. The repeated measures nature of these results suggests that global family functioning and bipolar episodes may fluctuate in concert with each other but that global family functioning is not associated with subsequent change in episode status. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Together in pain: Attachment-related dyadic processes and posttraumatic stress disorder.

We used actor–partner interdependence modeling to explore associations among attachment-related dyadic processes, posttraumatic stress disorder (PTSD) in war veterans, and secondary traumatic stress (STS) in their wives. A sample of 157 Israeli couples (85 former prisoners of war and their wives and a comparison group of 72 veterans not held captive and their wives) completed self-report scales assessing attachment insecurities (anxiety, avoidance) and PTSD symptoms. For both groups of veterans and their wives, attachment anxiety was associated with the severity of their own and their spouses' PTSD and STS. Avoidant attachment was associated with PTSD and STS only in couples that included a former prisoner of war. A complex pattern of associations involving avoidant attachment was observed in the actor–partner analyses of these couples. The study demonstrates that attachment-related dyadic processes play a role in the development and maintenance of PTSD in traumatized veterans and STS in their wives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suppression, accessibility of death-related thoughts, and cultural worldview defense: Exploring the psychodynamics of terror management.

Previous research has shown that after a mortality salience (MS) treatment, death thought accessibility and worldview defense are initially low and then increase after a delay, suggesting that a person's initial response to conscious thoughts of mortality is to actively suppress death thoughts. If so, then high cognitive load, by disrupting suppression efforts, should lead to immediate increases in death thought accessibility and cultural worldview defense. Studies 1 and 2 supported this reasoning. Specifically, Study 1 replicated the delayed increase in death accessibility after MS among low cognitive load participants but showed a reversed pattern among participants under high cognitive load. Study 2 showed that, unlike low cognitive load participants, high cognitive load participants exhibited immediate increases in pro-American bias after MS. Study 3 demonstrated that worldview defense in response to MS reduces the delayed increase in death accessibility. Implications of these findings for understanding both terror management processes and psychological defense in general are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relation between coal aromatic carbon concentration and proximate analysis fixed carbon

Good agreement has been obtained between measured proximate analysis values for fixed carbon (FC) and the predictions of a thermal decomposition model. The model provides a basis for understanding the relation between FC and coal structure and between FC measured under proximate analysis conditions and coke or char measured in other thermal decomposition experiments. The key parameters in the model are the aromatic carbon concentration (C_ar) and the tar yield. C_ar has been determined for 43 coals using quantitative infrared analysis. The aliphatic hydrogen concentration is measured from the absorption near 2900 cm^?1 and the aliphatic carbon concentration is computed assuming a stoichiometry of CH_1.8 C_ar is then computed by difference. The results verify the good correlation between C_ar and FC discussed by van Krevelen. To explain this correlation, use has been made of a coal thermal decomposition model which has been successful in simulating the quantity and composition of volatile components yielded under vacuum pyrolysis conditions. To apply the model to proximate analysis, it was necessary to estimate the tar yields obtained with thick beds and the amounts of O, N, H, and S which remain with the FC. The tar yields for proximate analysis conditions have been estimated to be $\text{1}\text{3}$ to $\text{1}\text{4}$ the yields for thin beds in vacuum. To determine the composition of the FC, measurements were made on a lignite and a bituminous char produced in a thin bed heated by a wire grid for the time (7 min) and temperature (950 °C) used in the proximate analysis, and on the FC residues from a proximate analysis volatile matter determination. Both residues give similar results, showing that approximately 10% of the ‘fixed carbon’ is not carbon. Values of FC computed with the model adjusted for the above conditions are in good agreement with the measured values.     

Correlation of coal volatile yield with oxygen and aliphatic hydrogen

An interesting correlation has been observed between the volatile yield for three coal conversion processes and the oxygen and aliphatic hydrogen (H_al) content of the coal. The three processes are: (1) rapid pyrolysis in vacuum, (2) hydropyrolysis at ≈10 MPa hydrogen, and (3) liquefaction with tetralin at 400 °C. The volatile yield for the first two processes and for low sulphur coals studied in the third process may be predicted with the equation: Yield≈0.8 O_T+15 H_al where: O_T, the organic oxygen concentration measured by ultimate analysis; and H_al is the aliphatic hydrogen concentration determined from Fourier Transform infrared (FTIR) measurements. The similarity of yields for these processes suggests that they are basically controlled by thermal decomposition. Justification for the above equation is offered by considering a recently developed model for thermal decomposition of coal. The correlation does not fit a group of high sulphur coals studied in the liquefaction programme. These coals have extremely high volatile yields which may be a result of catalytic activity.     

Preparation of a chelating poly(β-diketone) resin from poly(vinyl alcohol) and its use in the reversible complexing of metal ions

Summary A water-insoluble poly (-diketone) chelating resin has been prepared by the controlled oxidation of poly(vinyl alcohol) with chromic acid. The polymer forms stable complexes with divalent and trivalent cations, such as Co⁺², Cu⁺², Mn⁺², Ni⁺², Fe⁺³, Au⁺³, and UO₂ ⁺², and removes them completely from dilute aqueous solution. The ions may be recovered quantitatively from the resin complex by elution with dilute aqueous acid and the resin is reusable     

Formation of benzene polycarboxylic acids in the oxygen oxidation of solid by-products from coal-conversion processes (CCP) in an alkaline medium

Solid and liquid carbonaceous by-products have been obtained in both coal gasification and liquefaction processes. A study of the oxidation of the solid by-products was undertaken to determine what commercial chemicals could be derived from these materials. The oxygen oxidation of various coal-conversion-process by-products in 10% aqueous sodium hydroxide was investigated at 250 °C and a total pressure of 8.27 MPa (gauge). The products isolated were carbon dioxide and the organic extract, a complex mixture of aliphatic and aromatic acids. The benzene polycarboxylic acids were the major component of the organic extract.     

Isometry‐Aware Preconditioning for Mesh Parameterization

This paper presents a new preconditioning technique for large‐scale geometric optimization problems, inspired by applications in mesh parameterization. Our positive (semi‐)definite preconditioner acts on the gradients of optimization problems whose variables are positions of the vertices of a triangle mesh in ?² or of a tetrahedral mesh in ?³, converting localized distortion gradients into the velocity of a globally near‐rigid motion via a linear solve. We pose our preconditioning tool in terms of the Killing energy of a deformation field and provide new efficient formulas for constructing Killing operators on triangle and tetrahedral meshes. We demonstrate that our method is competitive with state‐of‐the‐art algorithms for locally injective parameterization using a variety of optimization objectives and show applications to two‐ and three‐dimensional mesh deformation.     

Hybrid Microwave Sintering of Infrared Transparent Nano‐Y3Al5O12 Synthesized by a Modified Combustion Technique

Infrared transparent ceramics found to have numerous civilian and defense applications. In the present work, Y₃Al₅O₁₂ nanoparticles were synthesized by an auto‐igniting modified single‐step combustion method. The structure and morphology of the as‐prepared powder revealed the phase purity and ultrafine nature of the powder having an average crystallite size of 16 nm and well‐defined lattice planes. Coupling of the resistive and microwave heating at precise proportion leads to a sintered density of the powder with 99.3% of the theoretical density at a temperature as low as 1470°C for a soaking duration of just 20 min. Marked reduction in grain size and the porosity was also observed for the hybrid sintered pellets. An average grain size of 167 nm was measured for the sintered pellets, which also showed a high transmittance of 80% in the UV–vis region and 82.5% in the mid‐IR region.