9,215 research outputs found

    Late diagenetic indicators of buried oil and gas. 2: Direct detection experiment at Cement and Garza fields, Oklahoma and Texas, using enhanced LANDSAT 1 and 2 images

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    The author has identified the following significant results. The Cement oil field, Oklahoma, was a test site for an experiment designed to evaluate LANDSAT's capability to detect an alteration zone in surface rocks caused by hydrocarbon microseepage. Loss of iron and impregnation of sandstone by carbonate cements and replacement of gypsum by calcite were the major alteration phenomena at Cement. The bedrock alterations were partially masked by unaltered overlying beds, thick soils, and dense natural and cultivated vegetation. Interpreters, biased by detailed ground truth, were able to map the alteration zone subjectively using a magnified, filtered, and sinusoidally stretched LANDSAT composite image; other interpreters, unbiased by ground truth data, could not duplicate that interpretation

    The impact of a post-take ward round pharmacist on the risk score and enactment of medication-related recommendations

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    There is a scarcity of published research describing the impact of a pharmacist on the post-take ward round (PTWR) in addition to ward-based pharmacy services. The aim of this paper was to evaluate the impact of clinical pharmacists' participation on the PTWR on the risk assessment scores of medication-related recommendations with and without a pharmacist. This includes medication-related recommendations occurring on the PTWR and those recommendations made by the ward-based pharmacist on the inpatient ward. A pre-post intervention study was undertaken that compared the impact of adding a pharmacist to the PTWR compared with ward-based pharmacist services alone. A panel reviewed the risk of not acting on medication recommendations that was made on the PTWR and those recorded by the ward-based pharmacist. The relationship between the risk scores and the number and proportion of recommendations that led to action were compared between study groups. There were more medication-related recommendations on the PTWR in the intervention group when a pharmacist was present. Proportionately fewer were in the 'very high and extreme' risk category. Although there was no difference in the number of ward pharmacist recommendations between groups, there was a significantly higher proportion of ward pharmacist recommendations in the "very high and extreme" category in those patients who had been seen on a PTWR attended by a pharmacist than when a pharmacist was not present. There were a greater proportion of "low and medium" risk actionable medication recommendations actioned on the PTWR in the intervention group; and no difference in the risk scores in ward pharmacist recommendations actioned between groups. Overall, the proportion of recommendations that were actioned was higher for those made on the PTWR compared with the ward. The addition of a pharmacist to the PTWR resulted in an increase in low, medium, and high risk recommendations on the PTWR, more very high and extreme risk recommendations made by the ward-based pharmacist, plus an increased number of recommendations being actioned during the patients' admission

    Smallholder value chains as complex adaptive systems: a conceptual framework

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    Conventional analyses of value chains involving smallholders and the design of interventions that seek to strengthen their role in them often fail to account for important features of value chain performance. Markets, institutional frameworks and business relationships are dynamic, and value chain performance varies accordingly. Shocks and sudden changes occur frequently and require successful adaptation. This paper develops an expanded conceptual framework to understand value chain performance based on the theory of complex adaptive systems. The framework combines seven common properties of complex systems: time, uncertainty, sensitivity to initial conditions, endogenous shocks, sudden change, interacting agents and adaptation. We outline how the framework can be used to ask new research questions, analyse case studies, and develop new tools to increase the ability for enhanced risk management and adaptation

    Magnitude and mechanisms of disequilibrium between predawn plant and soil water potentials

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    Journal ArticlePredawn plant water potential (Uw, measured with leaf psychrometers) and surrogate measurements made with the pressure chamber (termed Upc here) are used to infer comparative ecological performance, based on the expectation that these plant potentials reflect the wettest soil Uw accessed by roots. There is growing evidence, however, that some species exhibit substantial predawn disequilibrium (PDD), defined as plant Uw or Upc at predawn substantially more negative than the Uw of soil accessed by roots

    Particulate and aerosol detector

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    A device is described for counting aerosols and sorting them according to either size, mass or energy. The component parts are an accelerator, a capacitor sensor and a readout. The accelerator is a means for accelerating the aerosols toward the face of the capacitor sensor with such force that they partially penetrate the capacitor sensor, momentarily discharging it. The readout device is a means for counting the number of discharges of the capacitor sensor and measuring the amplitudes of these different discharges. The aerosols are accelerated by the accelerator in the direction of the metal layer with such force that they penetrate the metal and damage the oxide layers, thereby allowing the electrical charge on the capacitor to discharge through the damaged region. Each incident aerosol initiates a discharge path through the capacitor in such a fashion as to vaporize the conducting path. Once the discharge action is complete, the low resistance path no longer exists between the two capacitor plates and the capacitor is again able to accept a charge. The active area of the capacitor is reduced in size by the damaged area each time a discharge occurs

    Caught in the act: Implications for the increasing abundance of mafic enclaves during the eruption of the Soufriere Hills Volcano, Montserrat

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    An exceptional opportunity to sample several large blocks sourced from the same region of the growing Soufrière Hills lava dome has documented a significant increase in the presence of mafic enclaves in the host andesite during the course of a long-lived eruptive episode with several phases. In 1997 (Phase I) mafic inclusions comprised ~1 volume percent of erupted material; in 2007 (Phase III) deposits their volumetric abundance increased to 5–7 percent. A broader range of geochemically distinctive types occurs amongst the 2007 enclaves. Crystal-poor enclaves generally have the least evolved (basaltic) compositions; porphyritic enclaves represent compositions intermediate between basaltic and andesitic compositions. The absence of porphyritic enclaves prior to Phase III magmatism at Soufrière Hills Volcano suggests that a mixing event occurred during the course of the current eruptive episode, providing direct evidence consistent with geophysical observations that the system is continuously re-invigorated from depth
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