632 research outputs found

    Activity Coefficients of Adsorbed Mixtures

    Get PDF
    Experimental and simulated data for adsorption of gas mixtures on energetically heterogeneous surfaces like activated carbon and zeolites exhibit negative deviations from ideality. The deviations are large in some cases, with activity coefficients at infinite dilution equal to 0.1 or less. Similar molecules form ideal mixtures, but molecules of different size or polarity are nonideal. Equations for bulk liquid mixtures (Wilson, Margules, etc.) do not apply to isobars for adsorbed mixtures. A two-constant equation for activity coefficients as a function of composition and spreading pressure is in good agreement with theory, simulation, and experiment

    Canola : a promising oilseed (1991)

    Get PDF
    New 8/91/5M

    Canola : a promising oilseed (1993)

    Get PDF
    Canola is a promising alternative crop for Missouri because it is relatively easy to produce, requires no new investment of equipment, and offers competitive profits. Canola offers farmers an opportunity to help control soil erosion, produce a high-quality winter oilseed crop, and diversify cropping operations. Missouri grain producers today rely upon a few traditional crops such as corn, grain sorghum, soybeans and wheat. Canola and other alternative crops can help reduce the income risk associated with market fluctuations or weather/pest production losses affecting these primary crops

    Iluzija nagiba mjeseca

    Get PDF
    The moon tilt illusion is the startling discrepancy between the direction of the light beam illuminating the moon and the direction of the sun. The illusion arises because the observer erroneously expects a light ray between sun and moon to appear as a line of constant slope according to the positions of the sun and the moon in the sky. This expectation does not correspond to the reality that observation by direct vision or a camera is according to perspective projection, for which the observed slope of a straight line in three-dimensional space changes according to the direction of observation. Comparing the observed and expected directions of incoming light at the moon, we derive a quantitative expression for the magnitude of the moon tilt illusion that can be applied to all configurations of sun and moon in the sky.Iluzija nagiba mjeseca zapanjujući je raskorak između svjetlosne zrake koja osvjetljava mjesec i smjera sunca. Ona se povećava, jer promatrač pogrešno očekuje da zraka svjetla između sunca i mjeseca bude pravac konstantnog koeficijenta smjera s obzirom na položaj sunca i mjeseca na nebu. Ovakvo očekivanje ne odgovara stvarnosti kod koje je promatranje s direktnom osi pogleda, ili s kamerom, u skladu s perspektivom (centralnim projiciranjem) za koju se promatrani koeficijent smjera pravca u trodimenzionalnom prostoru mijenja s obzirom na os pogleda. Uspoređujući promatrane i očekivane smjerove zrake usmjerene na mjesec, izvodimo kvantitativan izraz za veličinu iluzije nagiba mjeseca koji se može primijeniti na sve položaje sunca i mjeseca na nebu

    Radio Astronomy

    Get PDF
    Contains reports on three research projects.National Aeronautics and Space Administration (Grant NGL 22-009-016)National Aeronautics and Space Administration (Grant NGL 22-009-421)National Science Foundation (Grant GP-20769)California Institute of Technology Contract 952568Sloan Fund for Basic Research (M. I. T. Grant 241

    Mean Field Theory of Collective Transport with Phase Slips

    Get PDF
    The driven transport of plastic systems in various disordered backgrounds is studied within mean field theory. Plasticity is modeled using non-convex interparticle potentials that allow for phase slips. This theory most naturally describes sliding charge density waves; other applications include flow of colloidal particles or driven magnetic flux vortices in disordered backgrounds. The phase diagrams exhibit generic phases and phase boundaries, though the shapes of the phase boundaries depend on the shape of the disorder potential. The phases are distinguished by their velocity and coherence: the moving phase generically has finite coherence, while pinned states can be coherent or incoherent. The coherent and incoherent static phases can coexist in parameter space, in contrast with previous results for exactly sinusoidal pinning potentials. Transitions between the moving and static states can also be hysteretic. The depinning transition from the static to sliding states can be determined analytically, while the repinning transition from the moving to the pinned phases is computed by direct simulation.Comment: 30 pages, 29 figure

    Hypertension treatment intensification among stroke survivors with uncontrolled blood pressure

    Get PDF
    Objective The study objective was to evaluate a pharmacist hypertension care management program within the patient-centered medical home. Methods This was a retrospective case-control study. Cases included all patients with hypertension who were referred to the care management program, and controls included patients with hypertension who were not referred to the program during the same 1-year period. Each case was matched to a maximum of 3 controls on the basis of primary care physician, age ±5 years, gender, diagnoses of diabetes and kidney disease, baseline systolic blood pressure ±10 mm Hg, and number of unique antihypertensive medications. Pharmacists provided a hypertension care management program under an approved scope of practice that allowed pharmacists to meet individually with patients, adjust medications, and provide patient education. Primary outcomes were systolic blood pressure and diastolic blood pressure at 6 and 12 months. Multivariate regression models compared each blood pressure end point between cases and controls adjusting for age, comorbidities, baseline blood pressure, and baseline number of blood pressure medications. Results A total of 573 patients were referred to the hypertension program; 86% (465/543) had at least 1 matched control and were included as cases in the analyses; 3:1 matching was achieved in 90% (418/465) of cases. At baseline, cases and controls did not differ with respect to age, gender, race, or comorbidity; baseline blood pressure was higher (139.9/80.0 mm Hg vs 136.7/78.2 mm Hg, P ≤ .0002) in the cases compared with controls. Multivariate regression modeling identified significantly lower systolic blood pressure for the cases compared with controls at both 6 and 12 months (6-month risk ratio [RR], 9.7; 95% confidence interval [CI], 2.7-35.3; 12-month RR, 20.3; 95% CI, 4.1-99.2; P < .01 for both comparisons). Diastolic blood pressure was significantly lower at 12 months (RR, 2.9; 95% CI, 1.2-7.1; P < .01) but not at 6 months (RR, 1.0; 95% CI, 0.31-3.4; P = .9) for the cases compared with controls. Conclusions Patients who were referred to the pharmacist hypertension care management program had a significant improvement in most blood pressure outcomes. This program may be an effective method of improving blood pressure control among patients in a medical home model of primary care

    Ground Testing of the EMCS Seed Cassette for Biocompatibility with the Tardigrade, Hypsibius dujardini

    Get PDF
    The European Modular Cultivation System, EMCS, was developed by ESA for plant experiments. We performed ground testing to determine whether ARC EMCS seed cassettes could be adapted for use with tardigrades for future spaceflight experiments. Tardigrades (water bears) are small invertebrates that enter the tun state in response to desiccation or other environmental stresses. Tardigrade tuns have suspended metabolism and have been shown to be survive exposure to space vacuum, high pressure, temperature and other stresses. For spaceflight experiments using the EMCS, the organisms ideally must be able to survive desiccation and storage in the cassette at ambient temperature for several weeks prior to the initiation of the experiment by the infusion of water to the cassette during spaceflight. The ability of tardigrades to survive extremes by entering the tun state make them ideal candidates for growth experiments in the EMCS cassettes. The growth substratum in the cassettes is a gridded polyether sulfone (PES) membrane. A blotter beneath the PES membrane contains dried growth medium. The goals of our study were to (1) determine whether tardigrades survive and reproduce on PES membranes, (2) develop a consistent method for dehydration of the tardigrades with high recovery rates upon rehydration, (3) to determine an appropriate food source for the tardigrades that can also be dehydrated/rehydrated and (4) successful mock rehydration experiment in cassettes with appropriate food source. We present results that show successful multigenerational growth of tardigrades on PES membranes with a variety of wet food sources. We have successfully performed a mock rehydration with tardigrades and at least one candidate food, protonema of the moss Polytrichum, that supports multigenerational growth and whose spores germinate quickly enough to match tardigrade feeding patterns post rehydration. Our results indicate that experiments on the ISS using the tardigrade, Hypsibius dujardini and other similar species could successfully be performed in the flight verified hardware of the EMCS seed cassettes
    corecore