653 research outputs found

    Numerical calculations of viscous compressible fluid flow over a flat plate and step geometry

    Get PDF
    Computer programs for numerical calculation of viscous compressible fluid flow over flat plat

    Calculation of two-dimensional turbulent flow fields

    Get PDF
    Navier-Stokes equation solutions for two- dimensional turbulent flow fields of compressible viscous flui

    Study of UV Degradation on Plastic (PET) Aerosols

    Get PDF
    The present study was aimed to explore the impact of UV radiation, from ‘real world’ environmental exposure, on the degradation of plastic PET aerosol containers. Additionally, the intent was to correlate the ‘real world’ environmental exposure to artificial sunlight, using a Xenon-Arc lamp, to develop a simulated test. The standardized methodology could then be used to evaluate the integrity of the plastic aerosol container and product, without the complexity of using ‘real world’ exposure. Through this study, a lab method was developed and validated that would simulate the effect of UV radiation using the Xenon-Arc. Moreover, a correlation was made for conditions inside the Xenon-Arc chamber that were conducive to testing a plastic pressurized container

    The genomic landscape of thyroid cancer tumourigenesis and implications for immunotherapy

    Get PDF
    Thyroid cancer is the most prevalent endocrine malignancy that comprises mostly indolent differentiated cancers (DTCs) and less frequently aggressive poorly differentiated (PDTC) or anaplastic cancers (ATCs) with high mortality. Utilisation of next-generation sequencing (NGS) and advanced sequencing data analysis can aid in understanding the multi-step progression model in the development of thyroid cancers and their metastatic potential at a molecular level, promoting a targeted approach to further research and development of targeted treatment options including immunotherapy, especially for the aggressive variants. Tumour initiation and progression in thyroid cancer occurs through constitutional activation of the mitogen-activated protein kinase (MAPK) pathway through mutations in BRAF, RAS, mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) pathway and/or receptor tyrosine kinase fusions/translocations, and other genetic aberrations acquired in a stepwise manner. This review provides a summary of the recent genetic aberrations implicated in the development and progression of thyroid cancer and implications for immunotherapy

    Smectite Formation in the Presence of Sulfuric Acid: Implications for Acidic Smectite Formation on Early Mars

    Get PDF
    The excess of orbital detection of smectite deposits compared to carbonate deposits on the martian surface presents an enigma because smectite and carbonate formations are both favored alteration products of basalt under neutral to alkaline conditions. We propose that Mars experienced acidic events caused by sulfuric acid (H2SO4) that permitted phyllosilicate, but inhibited carbonate, formation. To experimentally verify this hypothesis, we report the first synthesis of smectite from Mars-analogue glass-rich basalt simulant (66 wt% glass, 32 wt% olivine, 2 wt% chromite) in the presence of H2SO4 under hydrothermal conditions (approximately 200 degC). Smectites were analyzed by X-ray diffraction, Mossbauer spectroscopy, visible and near-infrared reflectance spectroscopy and electron microprobe to characterize mineralogy and chemical composition. Solution chemistry was determined by Inductively Coupled Plasma Mass Spectrometry. Basalt simulant suspensions in 11-42 mM H2SO4 were acidic with pH less than or equal to 2 at the beginning of incubation and varied from acidic (pH 1.8) to mildly alkaline (pH 8.4) at the end of incubation. Alteration of glass phase during reaction of the basalt simulant with H2SO4 led to formation of the dioctahedral smectite at final pH approximately 3 and trioctahedral smectite saponite at final pH approximately 4 and higher. Anhydrite and hematite formed in the final pH range from 1.8 to 8.4 while natroalunite was detected at pH 1.8. Hematite was precipitated as a result of oxidative dissolution of olivine present in Adirondack basalt simulant. Formation of secondary phases, including smectite, resulted in release of variable amounts of Si, Mg, Na and Ca while solubilization of Al and Fe was low. Comparison of mineralogical and solution chemistry data indicated that the type of smectite (i.e., dioctahedral vs trioctahedral) was likely controlled by Mg leaching from altering basalt and substantial Mg loss created favorable conditions for formation of dioctahedral smectite. We present a model for global-scale smectite formation on Mars via acid-sulfate conditions created by the volcanic outgassing of SO2 in the Noachian and early Hesperian

    Effectiveness of the Relaxation Response-Based Group Intervention for Treating Depressed Chinese American Immigrants: A Pilot Study

    Get PDF
    Background:: This study examined the feasibility, safety and efficacy of an 8-week Relaxation Response (RR)-based group. Methods:: Twenty-two depressed Chinese American immigrants were recruited. Outcomes measures were response and remission rates, the Hamilton Rating Scale for Depression, Clinical Global Impressions Scale, Quality of Life Enjoyment and Satisfaction Questionnaire, and the Multidimensional Scale of Perceived Social Support Scale. Results: Participants (N = 22) were 82% female, mean age was 53 (±12). After intervention, completers (N = 15) showed a 40% response rate and a 27% remission rate, and statistically significant improvement in most outcome measures. Discussion: The RR-based group is feasible and safe in treating Chinese American immigrants with depression

    Geochemistry of Carbonates on Mars: Implications for Climate History and Nature of Aqueous Environments

    Get PDF
    Ongoing research on martian meteorites and a new set of observations of carbonate minerals provided by an unprecedented series of robotic missions to Mars in the past 15 years help define new constraints on the history of martian climate with important crosscutting themes including: the CO_2 budget of Mars, the role of Mg-, Fe-rich fluids on Mars, and the interplay between carbonate formation and acidity. Carbonate minerals have now been identified in a wide range of localities on Mars as well as in several martian meteorites. The martian meteorites contain carbonates in low abundances (<1 vol.%) and with a wide range of chemistries. Carbonates have also been identified by remote sensing instruments on orbiting spacecraft in several surface locations as well as in low concentrations (2–5 wt.%) in the martian dust. The Spirit rover also identified an outcrop with 16 to 34 wt.% carbonate material in the Columbia Hills of Gusev Crater that strongly resembled the composition of carbonate found in martian meteorite ALH 84001. Finally, the Phoenix lander identified concentrations of 3–6 wt.% carbonate in the soils of the northern plains. The carbonates discovered to date do not clearly indicate the past presence of a dense Noachian atmosphere, but instead suggest localized hydrothermal aqueous environments with limited water availability that existed primarily in the early to mid-Noachian followed by low levels of carbonate formation from thin films of transient water from the late Noachian to the present. The prevalence of carbonate along with evidence for active carbonate precipitation suggests that a global acidic chemistry is unlikely and a more complex relationship between acidity and carbonate formation is present

    Electron and Neutron Electric Dipole Moments in the Focus Point Scenario of SUGRA Model

    Get PDF
    We estimate the electron and neutron electric dipole moments in the focus point scenario of the minimal SUGRA model corresponding to large sfermion masses and moderate to large tan⁥ÎČ\tan\beta. There is a viable region of moderate fine-tuning in the parameter space, around tan⁥ÎČ≃5\tan\beta \simeq 5, where the experimental limits on these electric dipole moments can be satisfied without assuming unnaturally small phase angles. But the fine-tuning constraints become more severe for tan⁥ÎČ>10\tan\beta > 10.Comment: 16 pages, LaTeX, 4 postscript figures. Very minor changes made in only a few sentences for clarification. Final version to appear in Phys. Rev.

    On the Origin of the -4.4 eV Band in CdTe(100)"

    Full text link
    We calculate the bulk- (infinite system), (100)-bulk-projected- and (100)-Surface-projected Green's functions using the Surface Green's Function Matching method (SGFM) and an empirical tight-binding hamiltonian with tight-binding parameters (TBP) that describe well the bulk band structure of CdTe. In particular, we analyze the band (B--4) arising at --4.4 eV from the top of the valence band at Γ\Gamma according to the results of Niles and H\"ochst and at -4.6 eV according to Gawlik {\it et al.} both obtained by Angle-resolved photoelectron spectroscopy (ARPES). We give the first theoretical description of this band.Comment: 17 pages, Rev-TEX, CIEA-Phys. 02/9

    Martian Atmospheric Methane Plumes from Meteor Shower Infall: A Hypothesis

    Get PDF
    Methane plumes in the martian atmosphere have been detected using Earth-based spectroscopy, the Planetary Fourier Spectrometer on the ESA Mars Express mission, and the NASA Mars Science Laboratory. The methane's origin remains a mystery, with proposed sources including volcanism, exogenous sources like impacts and interplanetary dust, aqueous alteration of olivine in the presence of carbonaceous material, release from ancient deposits of methane clathrates, and/or biological activity. To date, none of these phenomena have been found to reliably correlate with the detection of methane plumes. An additional source exists, however: meteor showers could generate martian methane via UV pyrolysis of carbon-rich infall material. We find a correlation between the dates of Mars/cometary orbit encounters and detections of methane on Mars. We hypothesize that cometary debris falls onto Mars during these interactions, depositing freshly disaggregated meteor shower material in a regional concentration. The material generates methane via UV photolysis, resulting in a localized "plume" of short-lived methane
    • 

    corecore