744 research outputs found
Microlite orientation in obsidian flow measured by synchrotron X-ray diffraction
Clinopyroxene and plagioclase (andesine) microlites in an obsidian flow from Glass Mountain (NE California, USA) display strong alignment. Synchrotron X-ray diffraction, coupled with Rietveld analysis, was used to quantify crystallographic-preferred orientation (CPO). Clinopyroxene, with a rod-shaped morphology, shows a strong alignment of [001] in the flow direction and (010) aligned parallel to the inferred flow plane. Andesine, with a platy morphology, displays an alignment of (010) platelets in the flow plane. Some pole densities exceed 90 multiples of random distribution. Applying a model of rigid ellipsoidal inclusions in a viscous matrix, the local pure shear strains are between 2 and 3
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The effect of CO2-induced dissolution on flow properties in Indiana Limestone: An in situ synchrotron X-ray micro-tomography study
The injection of CO -rich fluids in carbonate rocks results in an evolution of the pore space, with consequent changes in the hydraulic properties of the reservoir; how these properties evolve, particularly for parameters relevant to multiphase flow e.g. P (s), remains a topic of active research despite several decades of study. We have carried out an in situ synchrotron X-ray microtomography experiment to monitor pore structure evolution during dissolution of an Indiana Limestone core; the experiment involved flowing CO -saturated water through the core for 36 h and resulted in 10 volumes corresponding to different temporal stages of the dissolution process. The injection parameters corresponded to the flow velocities expected near the well-bore region of a shallow aqueous CO injection; fast flow rates with high reactant availability. Analysis of the tomographic data shows flow-enhanced dissolution i.e. channeling, and provides a time-resolved map of pore space alteration. Using the resulting 4D pore space volume, we modeled the evolution of capillary-pressure curves; this exercise demonstrates how pore structure evolution could impact the invasion and remobilization of non-wetting fluids, dramatically decreasing the entry pressure and the P in some parts of the sample. The modeling of permeability, using a Stokes solver approach, quantified the relationship of porosity vs. permeability; we found that a modest increase in porosity, especially when the channeling system is more developed, greatly affects permeability. These results demonstrate how movement of CO saturated brine near injected plumes might alter drainage dynamics near the plume boundary, thus leading to mobilization across subtle capillary barriers. 2 c 2 2 C
Introduction: the politicisation of permanent crisis in Europe
Taking stock of the numerous crises that have confronted Europe in the last decade, this special issue investigates the relationship between crisis and the politicisation of the process of European integration. It draws attention in so doing to the epistemic construction of crises. In this conceptual overview, we discuss first, how crises are framed and reframed in relation to the constitutive elements of a political community. Second, we explore the extent to which, and how, the emergence of different understandings of crisis and the ensuing frame competition between them contribute to such politicisation. By elucidating the link between the politics of a now seemingly permanent crisis in Europe and the politicisation of European integration, this introduction sets the framework informing all of the articles in this special issue
Assessing clinical and psychological features: who are patients showing a nocebo re-action during the drug challenge test?
The nocebo reaction, namely the undesirable effect of an inert substance (placebo), is a phenomenon rarely investigated in literature. A better knowledge of this reaction may help clinicians in the management of these patients in clinical practice. Patients with drug adverse reactions (ADR) undergoing the drug challenge test are an ideal model for studying the nocebo effect, and the study aims to investigate their clinical and psychological features. One hundred and twenty patients (Mage = 46.59, SD = 15.5; 82% female), of which 90 non responders and 30 with nocebo reactions (25%) were recruited, and completed a battery of psychological measures: State-Trait Anxiety Inventory X1-X2, Beck Depression Inventory II, Symptoms Checklist-90-R, Difficulties in Emotion Regulation Scale, Toronto Alexithymia Scale. Clinical features (individual characteristics and ADR clinical history) were collected by clinicians. The results show that older age (p = 0.002), low level of education (p = 0.039) and a depressive tendency (p = 0.030) appear to be potential risk factors for nocebo effects. Although none of the features related to the previous clinical history appear to represent a risk factor for the nocebo reactions (p minor 0.05), significant correlations between some of the clinical and psychological characteristics considered (p values from 0.005 to 0.042) help to better delineate the profile of these reactive patients. A specific training of the sanitary team about psychological aspects is recommendable
Suplementação alimentar de curta duração associada à sincronização do estro para aumentar o número de ovulações em cabras e ovelhas.
A nutrição é o fator mais importante que afeta diretamente o desempenho produtivo e reprodutivo dos animais. O principal objetivo da suplementação alimentar em fêmeas é aumentar o aporte de nutrientes para estimular a atividade reprodutiva, momento em que as cabras e ovelhas estarão prontas para serem colocadas com os reprodutores ou serem submetidas à inseminação artificial. Apresentamos, nesta publicação, os passos para fazer a suplementação alimentar de curta duração
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