Evaluación preliminar del tercer catálogo de Río Grande

En 1983 y 1989 se publicaron los dos primeros catálogos observados con Astrolabio desde la Estación Astronómica Río Grande. Actualmente se dispone del material observacional para la compilación del tercer catálogo. Para su primera elaboración se aplicó un algoritmo completamente distinto cuyos resultados son evaluados a través de la comparación con estrellas comunes a los dos catálogos publicados anteriormente.Asociación Argentina de Astronomí

Application of Exploratory Data Analytics EDA in Coal Seam Gas wells with Progressive Cavity Pumps PCPs

SPE-196528-MSArtificial lift methods typically drive Coal Seam Gas (CSG) wells, and Progressive Cavity Pump (PCP) isthe preferred method of lift with Australian CSG operators. CSG wells in Australia are typically equippedwith necessary instrumentation and automation systems to provide real-time data gathering for monitoringand control purposes. Real-time data gathered from CSG wells presents an opportunity to better understandPCP performance by identifying anomalous pump behavior. However, before undertaking any real-time analytics exercise, it is pertinent to carry out Exploratory DataAnalytics (EDA) to understand time series data behavior and extract relevant features; and this exerciseis particularly important with multi-variate data sets. Obtaining significant data features from multivariatetime series data can help define which analytics and machine learning methods could be exploited to analyzePCP performance in near real time. This paper will discuss EDA methodologies that can help streamline time-series data normalization andfeature extraction techniques. A three (3) year time-series dataset, gathered from forty-two (42) CSG wells,will be used to showcase EDA methodologies utilized as part of this research. All EDA activities coveredin this paper are based on the Python programming language and its supporting libraries.Fahd Saghir, M. E. Gonzalez Perdomo, and Peter Behrenbruc

A new combined quasigeoid model in Tierra del Fuego

This work focuses on the development of a combined quasigeoid model for Tierra del Fuego province. The Equivalent Source Technique (EST) is applied together with the remove-compute-restore technique in order to combine gravity and GPS/levelling observations and to obtain a quasigeoid model. This model features an improved accuracy in relation to previous models. A discussion about the geodetic reference system is also presented. Geodetic coordinates of all stations used were transformed to TDF08 to be in accordance with the new geodetic reference frame of Argentina. After a cross validation procedure it is determined that a 5cm (r.m.s.) quasigeoid model has been achieved for the major part of the province, fulfilling the requirements for its practical use. New Global Geopotential Models (GGM) are introduced in the discussion, particularly the EGM2008 which is used for evaluation purposes. It shows a 9cm agreement after its evaluation on the levelling lines

Modelo numérico con interacción corte-flexión en elementos de concreto armado

This paper presents a numerical model based on damage theory and fracture mechanics to simulate the cyclic behavior of reinforced concrete elements subjected to high shear forces and / or bending. Numerous tests were conducted on beams, columns and shear walls under cyclic loading. To establish the validity of the proposed model, are simulated the behavior curves of the specimens tested. The analytical results generally show a good correlation with experimental results. The proposed finite element was also validated by a test on a beam with double shear span (short-slender) subject cyclical lateral load. An adequate correlation was obtained between the numerical and experimental valuesEn este trabajo se propone un modelo numérico basado en la teoría del daño y de la mecánica de la fractura para simular el comportamiento histerético de elementos de concreto armado sometidos a altas fuerzas de corte y/o flexión. Se realizaron ensayos de comportamiento en vigas, columnas y muros sometidos a carga lateral cíclica reversible. Para establecer la validez del modelo propuesto, se simularon las curvas de comportamiento de los espécimenes ensayados experimentalmente. Los resultados analíticos, en general, muestran una buena correlación con los resultados experimentales. El modelo de comportamiento propuesto también fue validado con un ensayo de una viga con doble claro de cortante (corta-esbelta) obteniéndose una adecuada correlación entre los valores numéricos y experimentales

A novel model of brittleness index for shale gas reservoirs : confining pressure effect

Brittleness indices (BI) commonly used in the petroleum industry are based on elastic modulus or mineralogy that can be calculated from well logs. However, they both ignore the effect of confining pressure. Shale is usually distributed at different depth under different confining pressure. Models without considering the influence of confining pressure will directly lead to inaccuracy in BI calculation, thus resulting in the failure of hydraulic fracturing. In this work, we compared confining pressure with rock mechanics parameters and the microcrack quantity of a core, introduced "fracture toughness" to explain how confining pressure influences BI, and finally developed a new model to correct the effect of confining pressure in BI calculation. Fracture toughness is an important parameter that characterizing a rock’s resistance to a fracture. It increases with confining pressure, since an increase of confining pressure may close preexisting cracks and restrict the crack propagation. The results show that BI is usually larger at low confining pressure than at high pressure. Also, higher content in brittle mineral does not necessarily mean brittler. The results calculated by the new model, which considers the influence of Young’s modulus, Poisson’s ratio, tensile strength, confining pressure and fracture toughness in BI calculation, match well with experimental results.Yuan Hu, M. E. Gonzalez Perdomo, Keliu Wu, Zhangxin Chen, Kai Zhang, Dongqi Ji, He Zhon

Causas de aborto en ovinos de Uruguay: 100 casos, 2015-2021.

Este artículo se focaliza en la identificación d de causas de aborto en ovinos de diferentes departamentos del país, como aporte a la disminución de las pérdidas reproductivas, la mejora en el bienestar animal, y el diagnóstico de enfermedades zoonóticas