Simulation of the cyclic steam injection process in a petroleum reservoir by a finite difference mathematical model

A three-phase, one-dimensional radially layered reservoir simulator is programmed for a large memory digital computer. It is designed to provide a practical solution to the problem of determining optimum soak time during an intermittent steam injection process. The general approach is to (1) develop a representative mathematical model which describes the reservoir; and (2) employ a suitable numerical technique to solve the system of equations which comprises this model. The reservoir consists of concentric cylinders around the wellbore, a pay-zone stratified into thermally connected layers limited on the top and on the bottom by an impermeable cap and base rock, respectively. Mathematically speaking six unknown variables are considered; (pressure, temperature, water saturation, oil saturation, gas saturation and water evaporated (or condensed)) which are subsequently solved by six basic equations. The program was written in FORTRAN IV language and run on an IBM 360-50 digital computer --Abstract, page ii

Nutritional Indices of the Cotton Bollworm, Helicoverpa armigera, on 13 Soybean Varieties

The effects of 13 soybean varieties (356, M4, M7, M9, Clark, Sahar, JK, BP, Williams, L17, Zane, Gorgan3, and DPX) on nutritional indices of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), were determined at 25 ± 1° C, 65 ± 5% RH and a photoperiod of 16:8 L:D. Fourth instar larvae reared on Zane showed the highest efficiency of conversion of digested food (ECD) and approximate digestibility (AD) values (0.299 and 0.867, respectively) compared with other varieties. The lowest value of ECD and food consumed (FC) was on 356 (0.133 and 53.82 mg, respectively). The highest and lowest efficiency of conversion of ingested food (ECI) of fifth instar larvae (0.235 and 0.156, respectively) were on Zane and M4, respectively. The ECI and ECD values of whole larval instars were the highest on M7 (0.524 and 0.820, respectively) and lowest on Sahar (0.279 and 0.353, respectively). However, the highest and lowest value of consumption index (CI) was on M7 (7.351) and BP (3.462). Among the different varieties of soybean, the highest AD value was on M9 (0.858), and the lowest was on Zane (0.597). The results indicated that M4, Sahar, and JK were partially resistant to H. armigera

Palmarito: A Runaways´S (Cimarrones) Town

La formación y vida de la población afrodescendiente de Palmarito ubicada en la región sur del Lago de Maracaibo del estado Mérida en Venezuela, es el área a trabajar en la siguiente investigación. Palmarito a lo largo del tiempo ha desarrollado ciertos parámetros sociales, económicos, políticos y culturales propios dentro de la diversidad cultural existente en el país. Nuestro objetivo en esta contribución es exponer mediante el método de análisis histórico-crítico y etnográfi co -por medio de la tradición oral e historia oral-, una historia general del pequeño poblado [email protected] topic of this research is the formation and life of the African descendents´s town of Palmarito, located in the southern region of Lake Maracaibo in Mérida State, Venezuela. Palmarito has over time developed distinctive social, economic, political and cultural parameters, as part of the country´s diversity. Our goal is to present a general history of this small coastal town through its oral tradition and oral history, using the method of historical-critical and ethnographic analysi

Factibilidad financiera y planificación operativa de pimienta de Jamaica (Pimenta dioica) en Ecuador para exportación hacia Alemania

45 P.La producción de pimienta de Jamaica es limitada a la zona de Mesoamérica, el Caribe y Brasil en el continente americano, dando lugar a la oportunidad de producir en Ecuador, específicamente en la provincia de Santo Domingo de los Tsachilas que posee parámetros climatológicos similares a las necesidades del cultivo. Teniendo a la compañía alemana Don Limón como comprador interesado del producto; el proyecto tuvo como objetivo determinar si es factible realizarlo tomando en consideración aspectos técnicos del cultivo, aspectos comerciales y aspectos financieros. Entre los aspectos técnicos se consideraron los parámetros climatológicos, localización, propagación, trasplante, mantenimiento, fertilización, control de plagas y enfermedades, cosecha y producción; los aspectos comerciales fueron el precio CIF, logística del producto para el traslado de Ecuador a Alemania y los requisitos para exportar hacia Alemania y como aspectos financieros se realizó un flujo de caja con las variable independientes del proyecto y se obtuvieron los indicadores financieros del VAN (15%) y TIR; se analizó con la matriz GATOF y se pudo identificar las variables más sensibles para el proyecto. De esta manera se obtuvo que el proyecto es factible con una inversión de capital propio de $53,680; los indicadores financieros encontrados fueron: VAN (15$ 345,832 y TIR de 91.7%

José Arturo Saavedra C. (Comp.). África: Perspectivas sobre su cultura e historia.

[email protected]

Filtering of two-dimensional digital images using weighted averaging for adaptive selection of weights

Many digital images, especially in biomedical fields, contain some disturbances. The image analysis depends on quality of the images that is why reduction or elimination (if it is possible) the disturbances is the key issue. There are many methods of improvement in the quality of the images and thus improve the quality of the image analysis, among them one of the simplest method is low-pass filtering such as arithmetic mean or its generalization, weighted mean. The basic problem of the weighted mean is the proper selection of the weights. This can be done using adaptive algorithms. This paper presents several such algorithms which are modifications of the existing weighted averaging methods created originally for noise reduction in electrocardiographic signal. The description of the new filtering methods and a few results of its application are also presented with comparison to existing arithmetic average filtering

BIODEGRADACIÓN DE ASFALTENO Y RESINAS POR MICROORGANISMOS PRESENTES EN SUELO CONTAMINADO CON HIDROCARBURO / Biodegradation of Asphalt and Resins by Microorganism Coming from an Oil Contaminated Soil

La investigación se basó en la recuperación de un suelo de uso agrícola y ganadero contaminado con crudo medianoproveniente de derrames de pozos abandonados que presentan brotes naturales de crudo aplicando la técnica debiorremediación. La metodología consistió en seleccionar el área impactada y realizar tomas de muestras a una profundidadde 15 cm. Estas muestras se homogenizaron y se colocaron en cuatro biorreactores para su posterior tratamiento, uno comosuelo control o blanco y el resto tratado con medio mínimo surfactante (MMS), que aporta nutrientes necesarios para eldesarrollo de las bacterias. La concentración de hidrocarburos totales de petróleo (HTP) se determinó por gravimetría, ypara un tiempo de 30 días de tratamiento se lograron valores de 41 % y 61% en suelos no tratados y tratados, respectivamente,valores que están aún por encima de lo establecido en la normativa ambiental venezolana. Con respecto a la fracción deasfalteno, se registraron cambios en las réplicas, mientras que el suelo control se conservó estable, debido a que lasbacterias en presencia del MMS alcanzan los requerimientos necesarios para atacar la fracción del petróleo. En las fraccionesde resinas también se obtuvo un decrecimiento en el tiempo, siendo más significativo en las réplicas que en el suelo control.ABSTRACTThis study was based on the recovery of a soil used by agricultural and cattle activities contaminated with medium crudecoming from abandoned well spills that present natural seeps of crude applying the bioremediation technique. Themethodology consisted of selecting the affected area and taking samples to a depth of 15 cm, which were then homogenizedand placed in four bioreactors for later treatment, one as control while the rest were treated by surfactant minimum means(SMM) that provide necessary nutrients for the development of bacteria. The total petroleum hydrocarbons (TPH)concentrations were determined by gravimetric methods and during a 30 day treatment values of 41% and 61% in the soilstreated and not treated were obtained respectively, values which are above those established by Venezuelan environmentalnorms. With regards to asphalt fractions, changes in the retorts were registered, whereas the soil with control treatmentremained stable because the bacteria in the presence of the SMM reach the requirements necessary to attack the fractionof petroleum. In the fractions of resins there was also a decrease over time, more in the retorts that in the control treatment.Keywords: Asphalts, Resins, Total petroleum hydrocarbons (TPH), Bioremediation

Simultaneous recording and analysis of direct and indirect fetal electrocardiography

Recording and analysis of fetal heart rate variability is still the most common method for detection of early symptoms of fetal hypoxia. However, fetal heart rate obtained via ultrasound describes only mechanical activity of fetus heart. Limitations of this technique have stimulated the development of fetal electrocardiography. It ensures more precise determination of fetal heart rate and, which is more important, enables assessment of the morphology of the fetal QRS complexes. In this paper two techniques of obtaining the fetal electrocardiogram are described and their comparative study is presented

Comparison of instantaneous fetal heart rate extracted from abdominal and direct fetal electrocardiograms

This work is an attempt to assess the reliability of indirect abdominal electrocardiography as an alternative technique of fetal monitoring. As a reference signal we used the simultaneously acquired direct fetal electrocardiogram. Each recording consisted of four signals acquired from maternal abdomen and the reference signal acquired directly from fetal head. The first stage of our study concerned the signal loss episodes. In order to reduce the influence of incorrectly detected R-waves, some certain validation rules were applied. In the second stage, the corresponding intervals determined on basis of both acquisition methods were matched and the accuracy of fetal heart rate measurement was evaluated. Although the accuracy of abdominal electrocardiography turned out to be slightly lower than reported for ultrasound method, it still has some unique features deciding of its prevalence in a certain circumstances