Search

This paper shows a detailed description about an uncommon electric submersible pump (ESP) failure in Candelilla-5 well. This catastrophic failure generated fishing operations to recover the well, and additional cost for the well service. Candelilla-5 is located at Guataquia block, in the Llanos Orientales basin in Colombia. It is an oil producer well, 600 BOPD, 19.7 °API, an ESP as artificial lift system, at depth of 9482 ft TVD, with runlife of 173 days. The ESP suffered a suddenly stuck pump shaft during the operation; several start attempts were made, with no success. It was determined by the given evidence in this and the neighboring wells, that the probable cause was the presence of calcium carbonate (CaCO3). The electrical measurement of the all ESP system was in good conditions. Aiming to remove the CaCO3, two barrels of hydrochloric acid (HCl) at 15% concentration was injected into the pump, but it did not work, so a rig service was programmed. During the pulling of ESP string, only the tubing string plus pump discharge head was recovered. All the screws of pump discharge head were broke and the rest of ESP remained into the well as a fish. A Root Cause Failure Analysis (RCFA) was developed. The following methodology was used: (1) fractography analysis that showed a fracture plane between head and screw's body, (2) elemental chemical analysis using optical emission technique with spark source to find the screw's composition, (3) macro-attack testing for detecting residual stresses, (4) microstructural analysis to characterize the screw's material and fractures (5) microhardness profile to identify any screw's hardening, (6) X- ray diffraction in direction to identify incrustation and corrosion products and (7) hydrogen evolution test using HCl solution at 7,5 % and 15%, with the purpose of determining the hydrogen effects on steel properties. Once the RCFA was successfully completed, it was determined that the screws were fractured mainly because of three reasons: (1) High tension zones created due to high stresses during pump service, (2) the thermally treated material and (3) the presence of an acid solution in the environment, HCl, inducing an accumulation of hydrogen on the high tension zones, giving as a result the screw's hydrogen embrittlement, phenomenon responsible for the failure of the ESP from Candenilla-5 well. This paper aims to give details of the methodology, analysis from the root cause of the failure, feedbacks and recommendations to improve operations development on ESP.

Al analizar datos provenientes de poblaciones de plagas agricolas, regularmente se detecta que no cumplen los requerimientos teoricos para la aplicacion del ANDEVA clasico. El uso de transformaciones Box-Cox y de metodos estadisticos no parametricos resulta la alternativa mas utilizada para resolver este inconveniente. En el presente trabajo se exponen los resultados de la aplicacion de estas tecnicas a datos provenientes de Thrips palmi Karny muestreadas en plantaciones de papa (Solanum tuberosum L.) en el periodo de incidencia de la plaga. Se utilizo la docima X2 para la bondad de ajuste a la distribucion binomial negativa y de independencia para investigar la relacion entre los estratos de las plantas y los estados del insecto, se aplicaron siete transformaciones a los datos para satisfacer el cumplimiento de los supuestos basicos del ANDEVA, con las cuales no se logro eliminar la relacion entre la media y la varianza, por lo que se aplico el ANDEVA no parametrico de Kruskal-Wallis para comparar las densidades poblacionales del insecto. Los resultados permitieron seleccionar el estado larval del insecto y el estrato medio de la planta como elementos claves para disenar planes de muestreo para esta plaga.

Mature apples of 'Fuji' and 'Fuji' sports sourced from around the world contain unusual clumps of multicellular branched callus hairs between the parenchyma cells of the outer cortex. The hairs are similar morphologically to the white tufts found in the seed locules of some cultivars and to the aerial cells of apple callus grown on solid culture medium. Callus hairs were found to be particularly well developed in 'Fuji Suprema' from Brazil, and least developed in 'Fuji' from China. Hairs are also found in fruit of close relatives of 'Fuji' and some unrelated cultivars. Callus hairs proliferate in intercellular air spaces and also in larger cavities or lacunae which may have poor connectivity with other air spaces. In these locations they have the potential to restrict or modify the flow of oxygen and carbon dioxide in the outer part of apples, and thus may be one of the factors contributing to internal browning, a post-harvest disorder to which large or late-picked 'Fuji' in modified atmosphere storage are known to be vulnerable. The callus hairs are found within 17 mm of the skin and frequently contain starch even when starch has been metabolised from the surrounding parenchyma during ripening. The vacuoles of callus hairs are rich in autofluorescent compounds and may accumulate red pigment, particularly when growing close to the skin of deep red 'Fuji Suprema'. Initial observations with immunogold labelling have detected low levels of the allergen Mal d 3 associated with the plasmalemma of callus hairs. In corking disorders, callus hairs can invade necrotic cells and proliferate inside them.

El cáncer cervical es la malignidad más común entre las mujeres del tercer mundo y en Guatemala, es responsable del 40% de todos los cánceres en ambos sexos y del 60% de todos los cánceres femeninos, La presencia de Virus del Papiloma Humano (VPH) se considera entre otras, como el factor de riesgo más importante para el desarrollo del cáncer cervical. El presente estudio fue llevado a cabo con el propósito de determinar la prevalencia de los tipos de VPH en un grupo de pacientes de Guatemala con cáncer cervical así como para evaluar los factores de riesgo asociados al desarrollo de la enfermedad. Con ese propósito se llevó a cabo un estudio de casos y controles en 112 pacientes con cáncer cervical invasivo (casos) y 102 mujeres sanas (controles). Se obtuvieron biopsias cervicales y se investigó la presencia de, VPH usando dos métodos moleculares, captura de híbridos 2 (HC-2™. Digene Co.) y la reacción en cadena de la polimerasa (PCR). Se utilizó un cuestionario epidemiológico para evaluar otros factores de riesgo agrupados en factores de comportamiento sexual, factores reproductivos y factores sociodemográficos. La información fue recolectada durante una entrevista personal con los sujetos de estudio. Un total de 89% de las pacientes y tin 18% de los controles fueron positivos para ADN del Virus del Papiloma Humano y los tipos detectados con mayor frecuencia fueron el VPH 16, 18 y 45. La evaluación de factores de riesgo demostró valores de p de tendencia significativos (mayor riesgo de desarrollar cáncer cervical) para factores como: edad temprana de inicio de relaciones sexuales, número elevado de compañeros sexuales durante toda la vida y compañeros estables, elevado número de embarazos y partos vaginales, baja escolaridad y un origen étnico categorizado como indígena, al contrario de otros como el control prenatal durante el último embarazo, el cual es un factor que reduce el riesgo.

Review dei programmi di miglioramento genetico del melo in Italia

This note implements an unstructured decaying product matrix via the quasi-least squares approach for estimation of the correlation parameters in the framework of generalized estimating equations. The structure we consider is fairly general without requiring the large number of parameters that are involved in a fully unstructured matrix. It is straightforward to show that the quasi-least squares estimators of the correlation parameters yield feasible values for the unstructured decaying product structure. Furthermore, subject to conditions that are easily checked, the quasi-least squares estimators are valid for longitudinal Bernoulli data. We demonstrate implementation of the structure in a longitudinal clinical trial with both a continuous and binary outcome variable.

This paper aims at presenting the development and implementation of an approach to deal with fault location in transmission systems by Evolutionary Algorithms. The algorithm allows for the estimation of voltage sags and swells in non- monitored buses as well. An Evolutionary Strategy was applied to address the optimization problem, from the generation of a population of individuals that represent possible solutions to the problem to the evolutionary operators such as selection, mutation and crossover. Some variants of the basic approach were also considered in such a way to determine the fault location with better performance. A case study, based on the 30 bus IEEE study system, demonstrates the potential of the proposed methodology.

While the molecular mechanism underlying triethyllead (TEL) neurotoxicity is unknown, we hypothesize that triethyllead mediates an accelerated Cl-/OH exchange across neuronal membranes leading to prolonged depolarization and neuronal cell injury. As a test of this hypothesis we have investigated the effect of external ion modulation on triethyllead neurotoxicity in cerebellar granule cell culture. Cultures were prepared from neonatal rats and used 10-20 days in vitro. Cytotoxicity was assessed by lactate dehydrogenase (LDH) release and trypan blue exclusion. A slow, dose-dependent (1-30 microM TEL) release of LDH occurred after a variable latent period dependent upon [TEL]. External replacement of [Cl-]e by Na isothionate dramatically shifted the dose response curve to the left reflecting an accelerated stimulation of LDH release, while replacement of extracellular [Na+]e with equimolar choline chloride had a minimal protective effect. Similarly, high [Mg2+]e or low [Ca2+]e did not protect or potentiate TEL cytotoxicity. The low [Cl-]e accelerated TEL cytotoxicity was dependent on medium pH: alkaline pH potentiated the cytotoxicity. Low [Cl-]e had no significant effect on culture ATP over 5 hrs. ATP reduction was markedly stimulated by TEL in low Cl- medium in contrast to the minimal decline in [ATP] in the control medium. The reduction of ATP in the low [Cl-]e medium occurred prior to LDH or trypan blue staining release confirming that such reduction in [ATP] was not secondary to cell damage. Substituting K sulfate or Na sulfate for the Cl(-)-free medium revealed marked loss of ATP without LDH release in control and TEL supplemented cultures. These observations provide supporting evidence for the role of an abnormal Cl- flux in mediating TEL-induced neurotoxic injury. Specifically, the membrane depolarization is proportional to the gradient imposed by Cl- efflux/OH influx, stimulated by low [Cl-]e. The rapid loss in ATP appeared early, was not a secondary reflection of neuronal damage but a result of a combination of increased ion flux at the plasma membrane, stimulation of Na+/K+ ATPase and direct TEL-induced inhibition of mitochondrial oxidative phosphorylation.

El objetivo del estudio fue evaluar el efecto del agua de arroz con zanahoria en comparación con el agua de arroz sobre la duración de la diarrea, número de deposiciones y la consistencia de las heces en el tratamiento de la diarrea aguda en niños. Se realizó en una población constituida por 22 niños entre 6 y 60 meses de edad internados en el Hospital Nacional Pedro de Bethancourt de la Antigua Guatemala, 11 niños se asignaron aleatoriamente a un grupo control y 11 al experimental. Al grupo experimental se le administró agua de arroz con zanahoria y al control solo agua de arroz. Los niños estuvieron en un período de observación mínimo de 48 y máximo de 72 horas, el volumen promedio de agua de arroz y agua de arroz con zanahoria administrado fue de 32 onzas a cada niño, los niños con lactancia materna la continuaron a libre demanda, los niños destetados o con lactancia mixta, que tomaban formula infantil se les siguió proporcionando en la forma habitual y los que recibían alimentos sólidos se les brindó la dieta del hospital. La edad promedio de los niños participantes en el estudio fue de un año con nueve meses en el grupo experimental y un año con ocho meses en el control. El 41 % de los niños del grupo experimental eran hombres y el 9.0 % mujeres, y en el control, el 27 % eran hombres y el 23 % mujeres.