259 research outputs found

    Influence of the concentrations of xanthan gum, hydroxypropyl starch and potassium chloride on the flow properties of drilling fluid formulations

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    Drilling operation of oil wells involves high costs and risks. With recent discoveries of deeper reservoirs and difficult to access, there was an increase in the number of horizontal wells drilled and far-reaching, and, thereat, new challenges with operational problems. Fluids, or muds, drilling are essential to the well drilling process, confirming the need to study and find physical, rheological, and filtration properties, appropriate to the complexities in each section and the drilling stage. Optimized formulation is the one that comprises a safe operation, mitigation of operational problems, environmental protection, low cost, and high productivity. Thus, this paper offers the study of the rheological properties, and determination of filtrate volume, of the aqueous base fluid formulations, developed with polymeric additives. A high performance formulation, presenting technical-economical feasibility for drilling operations, was achieved using 0.43% m/v of viscosifier (xanthan gun), 0.57% m/v of filtrate controller (hydroxypropyl starch) and 4.57% m/v of clay swelling inhibitor (KCl).La operación de perforación de pozos de petróleo implica altos costos y riesgos. Con los recientes descubrimientos de depósitos más profundos y de difícil acceso, hubo un aumento en el número de pozos horizontales perforados y de largo alcance y, por lo tanto, nuevos desafíos con problemas operacionales. Los fluidos o los lodos de perforación son esenciales para el proceso de perforación del pozo, confirmando la necesidad de estudiar y encontrar propiedades físicas, reológicas y de filtración, adecuadas a las complejidades de cada sección ya la fase de perforación. La formulación optimizada es aquella que comprende una operación segura, mitigación de problemas operacionales, protección ambiental, bajo costo y alta productividad. Así, este trabajo ofrece el estudio de las propiedades reológicas y de volumen de filtrado de las formulaciones de fluidos de base acuosa, desarrolladas con aditivos poliméricos. Una formulación de alto rendimiento, presentando viabilidad técnico-económica para operaciones de perforación, fue alcanzada utilizando 0,43% mv de viscosificante (goma xantana), 0,57% m / v de controlador de filtrado (hidroxipropilamido) y 4,57% m / v de inhibidor de la hinchazón de arcilla (KCl)

    EC62-219 Nebraska Swine Production Report

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    This 1962 Nebraska Swine Production Report was developed by the Animal Husbandry Department of the University of Nebraska-Lincoln. Authors from the departments of Animal Husbandry, Agricultural Economics Veterinary Science, Agricultural Engineering contributed to this publication. It covers the following areas: breeding, feeding, economics, disease control, mechanization, housing and equipment

    Short and long term near-infrared spectroscopic variability of eruptive protostars from VVV

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    Numerous eruptive variable young stellar objects (YSOs), mostly Class I systems, were recently detected by the near-infrared Vista Variables in the Via Lactea (VVV) survey. We present an exploratory near-infrared spectroscopic variability study of 14 eruptive YSOs. The variations were sampled over 1-day and 1 to 2-year intervals and analysed in combination with VVV light curves. CO overtone absorption features are observed on 3 objects with FUor-like spectra: all show deeper absorption when they are brighter. This implies stronger emission from the circumstellar disc with a steeper vertical temperature gradient when the accretion rate is higher. This confirms the nature of fast VVV FUor-like events, in line with the accepted picture for classical FUors. The absence of Brγ emission in a FUor-like object declining to pre-outburst brightness suggests that reconstruction of the stellar magnetic field is a slow process. Within the 1-day timescale, 60% of H2-emitting YSOs show significant but modest variation, and 2/6 sources have large variations in Brγ. Over year-long timescales, H2 flux variations remain modest despite up to 1.8 mag variation in Ks. This indicates that emission from the molecular outflow usually arises further from the protostar and is unaffected by relatively large changes in accretion rate on year-long timescales. Two objects show signs of on/off magnetospheric accretion traced by Brγ emission. In addition, a 60% inter-night brightening of the H2 outflow is detected in one YSO

    Effect of deformation schedule on the microstructure and mechanical properties of a thermomechanically processed C-Mn-Si transformation-induced plasticity steel

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    Thermomechanical processing simulations were performed using a hot-torsion machine, in order to develop a comprehensive understanding of the effect of severe deformation in the recrystallized and nonrecrystallized austenite regions on the microstructural evolution and mechanical properties of the 0.2 wt pct C-1.55 wt pct Mn-1.5 wt pct Si transformation-induced plasticity (TRIP) steel. The deformation schedule affected all constituents (polygonal ferrite, bainite in different morphologies, retained austenite, and martensite) of the multiphased TRIP steel microstructure. The complex relationships between the volume fraction of the retained austenite, the morphology and distribution of all phases present in the microstructure, and the mechanical properties of TRIP steel were revealed. The bainite morphology had a more pronounced effect on the mechanical behavior than the refinement of the microstructure. The improvement of the mechanical properties of TRIP steel was achieved by variation of the volume fraction of the retained austenite rather than the overall refinement of the microstructure. <br /

    Prevalência e tendências temporais de transtornos mentais necessitando de tratamento de internação na cidade de Porto Alegre: Um estudo de toda a cidade incluindo todas as internações por motivo de saúde mental no sistema público de 2013-2017

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    Objectives: To investigate the 5-year prevalence of patients admitted to public inpatient care units due to a mental disorder, stratifying them by age group and diagnosis, and to assess trends of admissions over this time period in Porto Alegre. Methods: All admissions to the public mental health care system regulated by the city-owned electronic system Administração Geral dos Hospitais (AGHOS) were included in the analysis. The total population size was obtained by estimations of Fundação de Economia e Estatística (FEE). General information about 5-year prevalence of inpatient admissions, time-series trends e prevalence by age groups and diagnosis were presented. Results: There were 32,608 admissions over the 5-year period analyzed. The overall prevalence of patients was 1.62% among the total population, 0.01% among children, 1.12% among adolescents, 2.28% among adults and 0.93% among the elderly. The most common diagnosis was drug-related, followed by mood, alcohol-related and psychotic disorders. There was a linear trend showing an increase in the number of admissions from 2013 to the midst of 2014, which dropped in 2015. Conclusions: Admissions due to mental disorders are relatively common, mainly among adults and related to drug use and mood disorders. Time trends varied slightly over the 5 years. Prevalence rates in real-world settings might be useful for policymakers interested in planning the public mental health system in large Brazilian cities

    Lack of association between the Trp719Arg polymorphism in kinesin-like protein-6 and coronary artery disease in 19 case-control studies

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