Browsing by Fecha, starting with "1978"
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Item type: Item , La mujer y el sistema educativo en Colombia(National Pedagogic University, 1978) Elssy Bonilla de RamosEl análisis de cualquier aspecto relacionado con el sistema educativo, debe partir de la ubicación de éste dentro de las condiciones históricas de la sociedad que se considere. Esto por cuanto el sistema educativo se estructura como un medio para responder a la necesidad de formar una fuerza de trabajo entrenada y disciplinada, según el grado de desarrollo de las fuerzas productivas en una formación social históricamente determinada.Es decir, la educación se estructura para cumplir papeles determinados según condiciones históricas también determinadas. Paralelamente con esta argumentación, es necesario considerar que las ventajas y limitaciones del sistema educativo no pueden considerarse aisladamente como aspectos inherentes al sistema mismo, sino que, por el contrario, responden a situaciones concretas de la sociedad donde funciona dicho sistema. Además, desubicarlas de este contexto, equivale a limitar —cuando no a impedir— las posibilidades de comprender el por qué de dichas ventajas y de dichas limitaciones.Item type: Item , La fundamentación de la ética de kant y la peligrosidad de la terminología de los valores(1978) Carlos B. GutiérrezInformación no disponible.Item type: Item , El periódo de transición al vanguardismo en la poesía boliviana(Facultad de Humanidades y Ciencias de la Educación, 1978) Orihuela Ascarrunz, Juan CarlosTesis que trata sobre un estudio sobre la poesía boliviana, abarcando: las postrimeras del modernismo en Latinoamericana: una estimación teórica. Del modernismo a la vanguardia: transición critica. El periodo de transición al vanguardismo en la poesía boliviana.Item type: Item , Para una teoría del acto literario(Facultad de Humanidades y Ciencias de la Educación, 1978) Mariaca Iturri, Guillermo1. Para una epistemologia de la teoria. Teoria y realidad. Condiciones de la teoria. 2. Para un modelo de la teoria. Los sistemas. La racionalidad. 3. Critica y teoria. Critica de la ideologia. Critica de la linguistica. Para una teoria del discurso. 4. Para una teoria del texto literario. 5. Para una teoria del acto literario.Item type: Item , Accessory factors in the quantitative homeostasis of erythropoiesis(Elsevier BV, 1978) J L Scaro; Juan H. Tramezzani; M. E. Barrio RendoItem type: Item , Analysis of the Gc polymorphism in human populations by isoelectrofocusing on polyacrylamide gels. Demonstration of subtypes of the Gc1 allele and of additional Gc variants(Springer Science+Business Media, 1978) J. Constans; M. Viau; Hartwig Clevė; Geert De Jaeger; J.C. Quilici; M.J. PalissonItem type: Item , Properties Of Amphiphile/Oil/Water Systems At An Optimum Formulation For Phase Behavior(1978) Maurice Bourrel; Andrew M. Lipow; W. H. Wade; Robert Schechter; Jean‐Louis SalagerAbstract The oil recovery effectiveness of a chemical flood has been shown to be related to the phase behavior of the brine-oil-surfactant system. In particular, it is advantageous to formulate the system particular, it is advantageous to formulate the system so that middle phases are formed. There are, however, an infinite number of surfactant cosurfactant (alcohol) combinations which will give the desired phase behavior. The selection of the preferred system out of this infinity of possible systems is an optimization problem and is the subject of this paper. problem and is the subject of this paper. An extensive study of the interfacial tension of dodecyl ortho xylene sulfonate sodium salt, as a function of salinity, alcohol and hydrocarbon molecular weight has been conducted. The results reveal that certain formulations may be preferred since the interfacial tension of some systems at optimum conditions is smaller than others. Indeed, conditions giving a global interfacial tension minimum were found. It is also known that for enhanced oil recovery, it is desirable to maintain miscibility between the chemical slug and the reservoir fluids as long as possible. This means that the height of the possible. This means that the height of the multiphase region should be minimized. This study show that the height can be minimized by a proper formulation. Introduction A correlation relating the variables deft optimum systems for improved oil recovery has be reported. This equation gives the optimum salinity, S*, as a function of the alkane carbon number of the oil, ACN, the alcohol and a parameter, sigma, which is characteristic of the surfactant as follows: (1) where K is a constant equal to 0.16 for all alkylaryl sulfonates and f(A) is a function of alcohol type and concentration known for alcohols heavier than C5. The dots indicate that other variables, such as the water-oil ratio (WOR) and the temperature, have been omitted since they are not considered in this work. Equation 1 applies if WOR = 4 and T = 25 degrees C. The ratio sigma/K has been called the EPACNUS and is the extrapolated preferred alkane carbon number at unit salinity and preferred alkane carbon number at unit salinity and without alcohol, since f(A) is defined so that it vanishes as the alcohol concentration goes to zero. Equation 1 represents a plane in the space in S,ACN and f(A) as shown in Figure 1, and any point on this plane is an optimum system in the following sense. For a given oil and surfactant system, a middle phase will be observed over a range of salinities and the midpoint of this salinity range will be called the optimum salinity. Furthermore, the surfactant system is said to be an optimum one. This implies that a series of experiments in which a property important to improved oil recovery, such property important to improved oil recovery, such as interfacial tension or amount of surfactant needed to solubilize certain volumes of water and oil, will yield a minimum value of the property when a point on the plane is reached. Thus, a series of interfacial tension measurements will reveal a minimum value at the point where line 4 shown in Figure 1 pierces the plane. (Perhaps, it would be more pierces the plane. (Perhaps, it would be more precise to assert that the minimum will occur in the precise to assert that the minimum will occur in the vicinity of the plane rather than on it. This point is further clarified in a subsequent section.) If the experiment is repeated at a different salinity or alcohol concentration or both, then the minima of the properties in question will be found at the new point at which a vector parallel to line 4 intersects the plane. If the values of the minima are different at the two points, then one point on the plane may be preferred to the other with regard to plane may be preferred to the other with regard to efficiency of oil recovery. Thus, it is appropriate to ask if all points on the optimum plane are equivalent with regard to oil recovery. This is the question addressed in this paper.Item type: Item , La antipoesía de Nicanor Parra(University of Concepción, 1978) Revista AteneaItem type: Item , Fundamentos matemáticos de medición en ciencias empíricas(LA Referencia, 1978) Siegfried WeberUn método y al mismo tiempo una característica de las llamadas ciencias naturales como física, química, etc., consiste en medir propiedades de objetos esto es, la medición (ver p. ej. [1] V. Helmholtz, [2] 0. Hölder)Item type: Item , Food aid for supplementary feeding programmes(Elsevier BV, 1978) Simon MaxwellItem type: Item , Anomalous sublinear behaviour of photoresponse in monocrystal of ZnTe(Springer Science+Business Media, 1978) N.V. Joshi; J. AponteItem type: Item , Centro administrativo y de investigación de una compañía de seguros Viena – Austria(Spanish National Research Council, 1978) Kurt Hlaweniczka; Kurt KossEste edificio tiene forma de una cruz, con diez torres, cuatro de ellas con una altura de 70 m y las otras seis con una altura de 45 m. Su rasgo más característico son unas columnas delgadas de acero llenas de agua, sobre las que se apoyan los forjados de las plantas. Estas columnas, a su vez, se apoyan sobre vigas transversales colocadas sobre las vigas-cajón que unen las torres. Las torres fueron realizadas mediante encofrados deslizantes, mientras las vigas-cajón lo fueron con cimbras. En diversas fases de la construcción se utilizaron rayos ¡infrarrojos para conseguir un endurecimiento rápido del hormigón. El edificio consta de una instalación de elaboración electrónica de datos, una sala de enseñanza, comedor, sala de estar, etc.Item type: Item , CALIBRATION AND THE RADIOCARBON CHRONOLOGY OF LATE MINOAN IB(Wiley, 1978) P. P. Betancourt; H. N. MICHAEL; Gail WeinsteinItem type: Item , Pulmonary gas exchange, diffusing capacity in natives and newcomers at high altitude(Elsevier BV, 1978) J. Vincent; M F Hellot; Enrique Vargas; H. Gautier; P Pasquis; Richard LefrançoisItem type: Item , PROPERTIES OF AMPHIPHILE/OIL/WATER SYSTEMS AT AN OPTIMUM FORMULATION FOR PHASE BEHAVIOR(1978) Maurice Bourrel; Andrew Lipow; W.H. Wade; R.S. Schechter; Jean‐Louis SalagerProperties Of Amphiphile/Oil/Water Systems At An Optimum Formulation For Phase Behavior Maurice Bourrel; Maurice Bourrel University of Texas at Austin Search for other works by this author on: This Site Google Scholar Andrew M. Lipow; Andrew M. Lipow University of Texas at Austin Search for other works by this author on: This Site Google Scholar W.H. Wade; W.H. Wade University of Texas at Austin Search for other works by this author on: This Site Google Scholar R.S. Schechter; R.S. Schechter University of Texas at Austin Search for other works by this author on: This Site Google Scholar Jean-Louis Salager Jean-Louis Salager Universidad de los Andes Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Fall Technical Conference and Exhibition, Houston, Texas, October 1978. Paper Number: SPE-7450-MS https://doi.org/10.2118/7450-MS Published: October 01 1978 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Bourrel, Maurice, Lipow, Andrew M., Wade, W.H., Schechter, R.S., and Jean-Louis Salager. "Properties Of Amphiphile/Oil/Water Systems At An Optimum Formulation For Phase Behavior." Paper presented at the SPE Annual Fall Technical Conference and Exhibition, Houston, Texas, October 1978. doi: https://doi.org/10.2118/7450-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractThe oil recovery effectiveness of a chemical flood has been shown to be related to the phase behavior of the brine-oil-surfactant system. In particular, it is advantageous to formulate the system particular, it is advantageous to formulate the system so that middle phases are formed. There are, however, an infinite number of surfactant cosurfactant (alcohol) combinations which will give the desired phase behavior. The selection of the preferred system out of this infinity of possible systems is an optimization problem and is the subject of this paper. problem and is the subject of this paper. An extensive study of the interfacial tension of dodecyl ortho xylene sulfonate sodium salt, as a function of salinity, alcohol and hydrocarbon molecular weight has been conducted. The results reveal that certain formulations may be preferred since the interfacial tension of some systems at optimum conditions is smaller than others. Indeed, conditions giving a global interfacial tension minimum were found.It is also known that for enhanced oil recovery, it is desirable to maintain miscibility between the chemical slug and the reservoir fluids as long as possible. This means that the height of the possible. This means that the height of the multiphase region should be minimized. This study show that the height can be minimized by a proper formulation.IntroductionA correlation relating the variables deft optimum systems for improved oil recovery has be reported. This equation gives the optimum salinity, S*, as a function of the alkane carbon number of the oil, ACN, the alcohol and a parameter, sigma, which is characteristic of the surfactant as follows:(1)where K is a constant equal to 0.16 for all alkylaryl sulfonates and f(A) is a function of alcohol type and concentration known for alcohols heavier than C5. The dots indicate that other variables, such as the water-oil ratio (WOR) and the temperature, have been omitted since they are not considered in this work. Equation 1 applies if WOR = 4 and T = 25 degrees C. The ratio sigma/K has been called the EPACNUS and is the extrapolated preferred alkane carbon number at unit salinity and preferred alkane carbon number at unit salinity and without alcohol, since f(A) is defined so that it vanishes as the alcohol concentration goes to zero.Equation 1 represents a plane in the space in S,ACN and f(A) as shown in Figure 1, and any point on this plane is an optimum system in the following sense. For a given oil and surfactant system, a middle phase will be observed over a range of salinities and the midpoint of this salinity range will be called the optimum salinity. Furthermore, the surfactant system is said to be an optimum one. This implies that a series of experiments in which a property important to improved oil recovery, such property important to improved oil recovery, such as interfacial tension or amount of surfactant needed to solubilize certain volumes of water and oil, will yield a minimum value of the property when a point on the plane is reached. Thus, a series of interfacial tension measurements will reveal a minimum value at the point where line 4 shown in Figure 1 pierces the plane. (Perhaps, it would be more pierces the plane. (Perhaps, it would be more precise to assert that the minimum will occur in the precise to assert that the minimum will occur in the vicinity of the plane rather than on it. This point is further clarified in a subsequent section.) If the experiment is repeated at a different salinity or alcohol concentration or both, then the minima of the properties in question will be found at the new point at which a vector parallel to line 4 intersects the plane. If the values of the minima are different at the two points, then one point on the plane may be preferred to the other with regard to plane may be preferred to the other with regard to efficiency of oil recovery. Thus, it is appropriate to ask if all points on the optimum plane are equivalent with regard to oil recovery. This is the question addressed in this paper. Keywords: Upstream Oil & Gas, Schechter, salinity, optimum plane, Phase Behavior, diagram, ACN, formulation, PVT measurement, concentration Subjects: Fluid Characterization, Improved and Enhanced Recovery, Phase behavior and PVT measurements This content is only available via PDF. 1978. Society of Petroleum Engineers You can access this article if you purchase or spend a download.Item type: Item , El testamento del gobernador intendente de la provincia de Cochabamba, don Francisco Viedma y Narvaez.(Área Vicerrectorado, 1978) Honorable Alcaldía Municipal.La publicación del notable Testamento del gran Gobernador intendente de la provincia de Cochabamba, constituye un homenaje de la H. Alcaldía Municipal de esta capital a su memoria, y una cordial y significativa adhesión a los actos conmemorativos al bicentenario de la fundación de la ciudad de Viedma, capital de la provincia de Rio Negro de la hermana república Argentina.Item type: Item , High gradient magnetic separation applied to tin minerals(IEEE Magnetics Society, 1978) M. Arellano; G.Z. ZambranaThe present work reports the application of wet High Gradient Magnetic Separation, HGMS, to the recovery of weakly paramagnetic particles of very small dimensions. Pure minerals of different iron content were recovered magnetically with applied magnetic field intensities of up to 19 kOe under various conditions of flow velocity and separating matrix density. Tourmaline mineral, the main impurity in tin ore, can be recovered with a maximum of 63% efficiency in a single passing of HGMS at maximum field and 6 cm/sec flow velocity whereas cassiterite mineral (SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ) from the same ore deposit and particle size can be recovered with 37% efficiency. With a second passing of HGMS tourmaline was recovered with an increase of 14% in efficiency. From these results it seems possible that one could separate tourmaline minerals from cassiterite minerals with the appropriate conditions of magnetic field intensity, flow velocity and separating matrix density.Item type: Item , Qué son las sociedades intermedias(1978) Lino Rodríguez Arias BustamanteQué son las sociedades intermedias?Item type: Item , A administração de recursos globais: o futuro dos negócios: norte ou sul?(Fundação Getúlio Vargas, 1978) André van DamItem type: Item ,