Estimates of genetic parameters for female fertility traits from a dairy selection experiment for fat plus protein by using random regression and linear-threshold animal models

The main objective was to evaluate different models to improve the genetic analysis of days open (DO) in dairy cattle. Thus, three studies were conducted: 1) to evaluate the use of a linear random regression model for DO; 2) to study the genetic variation of calving success (CS); and 3) to evaluate the joint analysis of DO and CS by a threshold linear animal model. The objective of the first study was to investigate the feasibility of using a linear Legendre random regression model for the analysis of female fertility as expressed by DO. The analysis provided insight about the kind and amount of variation over the trajectory for age at calving from 24 to 90 mo. An aging and genetic component of female fertility was discovered. Heritability ranged from 0.07 to 0.10 from 24 to 72 mo. Permanent environmental correlations between fixed ages at calving changed from positive to negative values with greater distance between days open in young cows and days open in older cows; r(24,36) = 0.88, r(24,72) = -0.65. The random regression animal model is a better alternative to a repeatability animal model for estimation of variance components of DO. However, the assumption of genetic correlation of unity between adjacent parities is not realistic. Further research is needed to evaluate the advantages of using random regression model on the genetic analysis of DO. The objective of the second study was to investigate genetic parameters for calving success (CS) at different parity groups. Three definitions of CS were evaluated: CS-B had two categories (1=success and 2=failure), CS-T (1=success, 2= failure with opportunity to calve, and 3=failure without opportunity to calve), and CS-T2 (1=success, 2= failure without opportunity to calve, and 3= failure with opportunity to calve). Data from 1236 Holstein females from parity 0 to 5 were analyzed with threshold animal model. Posterior means of heritability for CS-B from parity 0 to 5 were slightly lower than those for CS-T. Posterior means of heritability for CS-B were 0.16(.08), 0.08(.03), 0.23(.07), 0.23(0.07), 0.24(.08) and 0.17(.08) for parity 0 to 5, respectively. Posterior means of heritability for CS-T were 0.17(.08), 0.10(.03), 0.21(.06), 0.22(0.07), 0.28(.08) and 0.21(.08) for parity 0 to 5, respectively. Posterior means of heritability for CS-T2 were 0.10(.07), 0.09(.04), 0.29(.06), 0.27(0.08), 0.24(.08) and 0.30(.09) for parity 0 to 5, respectively. Posterior means of genetic correlations between adjacent calving opportunities for CS-B, CS-T, and CS-T2 were variable in sign and magnitude with high posterior standard deviations. Our results indicate that CS-B, CS-T, and CS-T2 have substantial genetic variation to allow genetic improvement of female fertility. Some advantages of using CS for genetic evaluation of sires for female fertility is that it includes fertility performance of both heifer and lactating cows and it takes into account censored records for days open. The objective of the third study was to investigate genetic parameters for both DO and CS at different parity groups. The joint analysis of DO with CS-B, CS-T, and CS-T2 were done by a linear-threshold animal model. Data from 1236 Holstein females from parity 0 to 4 were used. Posterior means of heritability for CS-B, CS-T, and CS-T2 were low to moderate. Posterior means of heritability for CS-B from parity 0 to 4 were similar than those for CS-T and CS-T2. Posterior means of CS-B heritability were 0.14(.04), 0.09(.03), 0.28(.07), 0.25(0.06), and 0.26(.06) for parity 0 to 4, respectively, CS-T heritability posterior means were 0.13(.04), 0.09(.03), 0.26(.06), 0.24(0.06), and 0.28(.06) for parity 0 to 4, respectively, and CS-T2 heritability posterior means were 0.15(.04), 0.09(.03), 0.28(.06), 0.26(0.06), and 0.26(.06) for parity 0 to 4, respectively. Posterior means of heritability for DO from joint analysis with CS-B, CS-T and CS-T2 were similar, and they increased from low to moderate with parity. Posterior means of genetic correlations between DO and CS in the same parity were positive and varied from low to moderate, but they had large posterior standard deviations. CS is a categorical trait with similar genetic variation as DO and it is analyzed jointly with DO to make effective use of the genetic correlation between these two traits in lactating cows. The joint analysis can identify cows with greater genetic merit for conception at an earlier stage of lactation and greater success at maintenance of pregnancy

Desing of a foam slurry for cementing oil wells in the field cira in Santander (Colombia)

En el siguiente trabajo de grado, se puede encontrar una breve descripción de los requerimientos para la cementación de pozos petroleros en el campo La Cira ubicada en el departamento de Santander en Colombia. Posteriormente mediante una matriz de mezcla de aditivos se realizaron 12 diseños de lechadas espumosas teniendo en cuenta que para cada diseño se tuvieron que determinar las variables de resistencia a la compresión tiempo de bombeabilidad, viscosidad plástica y su densidad, esta matriz de prueba determino la variación de aditivos, según su aplicabilidad. La selección del diseño fue el resultado de las pruebas de laboratorio realizadas según la norma API 10A y API 10B. La validación de la lechada espumosa que fue elegida se le debe realizar una simulación Hidráulica donde determino la incidencia que tienen todos los fluidos sobre la formación Tenerife, el cual su ECD para la presión de poro no debe ser menor a 8,4ppg y la presión final no mayor a 10 ppg para evitar que una fractura de la formación. Finalmente, se desarrolla el capítulo financiero teniendo en cuenta la rentabilidad del proyecto.TUCKER ENERGY SERVICESIn the following work of degree, a brief description of the requirements for the cementation of oil wells in the field La Cira located in the department of Santander in Colombia can be found. Then, through a matrix of mixtures of additives, 12 designs of foamed slurries were made taking into account that for each design the variables of compressive strength, time of pumpability, plastic viscosity and its density had to be determined, this test matrix determined the variation of additives, according to their applicability. The design selection was the result of the laboratory tests performed according to API 10A and API 10B standards. A Hydraulic simulation should be performed on the foamed slurry that was chosen, where the influence of all fluids on the Tenerife formation was determined, which ECD for the pore pressure should not be less than 8.4ppg and the final pressure should not be greater than 10 ppg, to avoid a fracture of the formation. Finally, the financial chapter is developed taking into account the profitability of the project

UNA COMPRENSIÓN DEL OCIO DESDE LA TEORÍA DE LA ACCIÓN COMUNICATIVA

This study seeks to contribute to the understanding of leisure. For this analysis we will interpret leisure via The Theory of Communicative Action (TCA) of Jürgen Habermas (1987a and 1987b). First, we aim to understand the most important categories of the TCA, especially the concepts of Life World (LW), Money Systems (MS) and Power Systems (PS), and then, we interpret leisure via TCA. In a second step, we seek to strengthen this referential by bringing other interpretations of the object leisure, such as: leisure and work, leisure and postmodern, leisure and pleasure; showing how the Habermasian referential can contribute to the interpretation of contemporary leisure. To conclude, we bring a definition of leisure, based on all the theoretical construction presented in this study. This study is theoretical exploratory, based on understanding of the theories of leisure, the Habermasian reference (TCA) and the understanding of leisure via this reference.Este estudo visa contribuir para a compreensão do lazer. Para isso, nós interpretamos o lazer pela Teoria da Ação Comunicativa (TAC) de Jürgen Habermas (1987a;1987b). Primeiro, objetivamos compreender as categorias mais importantes da TAC, especialmente os conceitos de Mundo da Vida (MV), Sistema Dinheiro (SD) e Sistema Poder (SP) e, posteriormente, interpretamos o lazer pela TAC. Numa segunda etapa, buscamos reforçar esse referencial ao trazer outras interpretações para o objeto lazer, como: lazer e trabalho, lazer e pós-moderno, lazer e prazer; demonstrando como o referencial habermasiano pode contribuir para a interpretação do lazer contemporâneo. Para concluir, trazemos a definição de lazer, baseada em toda a construção teórica apresentada no estudo. Esse estudo é teórico exploratório, baseado na compreensão de teorias do lazer, na referência habermasiana (TAC) e na compreensão do lazer por essa referência. Ese estudio busca contribuir para la comprensión del ocio. Para este análisis, nosotros interpretamos el ocio por la Teoría de la Acción Comunicativa (TAC) de Jürgen Habermas (1987a; 1987b). Primero, procuramos comprender las categorías más importantes de la TAC, especialmente los conceptos de Mundo de la Vida (MV), Sistema Dinero (SD) y Sistema Poder (SP) y, posteriormente, interpretamos el ocio por la TAC. En una segunda etapa, intentamos fortalecer ese referencial al traer otras interpretaciones para el objeto ocio como: ocio y trabajo, ocio y pos-modernismo, ocio y placer; demostrando como el referencial habermasiano puede contribuir para la interpretación del ocio contemporáneo. Para concluir, formulamos una definición de ocio, basada en toda la construcción teórica presentada en el estudio. Este estudio es teórico exploratorio, basado en la comprensión de teorías del ocio, en la referencia habermasiana (TAC) y en la comprensión del ocio por esa referencia.

Numerical analysis of the vapor flow in an axially rotating heat pipe in drilling processes

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Numerical analysis of the hydrodynamics of the flow in an axially rotating heat pipe

A numerical study is conducted on the vapor and liquid flow in a wick structure of an axially rotating heat pipe. For the vapor, the governing equations are the Navier-Stokes. For the liquid a space average of the Navier-Stokes equation is performed and a porous media model is introduced for the cross correlation that appears from the averaging process. A control volume approach on a staggered grid is used in the development of the computer program. Suction and blowing velocities are used as boundary conditions of the vapor and liquid, which are related to a local heat flux input in the evaporator section, and local heat flux output in the condenser section, respectively. The aim behind this study is the application of heat pipes in drilling applications. A triangular heat flux distribution is assumed in the evaporator due to the higher heat flux generated at the tip of the drill. A parametric study is conducted to analyze the effect of different parameters such as rotational speeds, saturation conditions, porosity, permeability and dimensions of the wick structure in the porous medium. These parameters significantly affect the pressure drop in the heat pipe and allow predicting failure conditions, which is critical in the design of heat pipes in drilling applications. The results of this study will be useful for the complete analysis of the heat pipe performance including the solution of the heat transfer on the solid wall as a conjugate problem

Early Holocene water well in the Pampas of Argentina: Human responses to water shortage events

Water wells are ethnographically and archaeologically described in Australia and the plains of North America. Recently, a prehistoric water well from the early Holocene was recorded in the Pampas of Argentina. The aim of this paper is to present the main characteristics of the water well, considering its form, dimension, sediment analyses (texture and chemical parameters), and material culture content. This is the first water well recorded in the Pampas of Argentina. Consequently, a discussion about natural or cultural origins of this kind of features is provided. An evaluation of similarities and differences with well-described water wells from the United States and Australia is included in order to highlight the cultural origin of the pit. Also, the meaning of the cultural response to water availability in terms of early-Holocene hunter–gatherer adaptations as well as the implications of this strategy for understanding paleoenvironmental scenarios of the Pampas of Argentina are discussed. The well seems to have mitigated an exceptional lack of surface water in the eastern Pampas or offered an alternative for the non-drinkable quality of the available surface water. The strategy of digging water wells was available in the behavioral repertoire of the Pampean hunter–gatherer populations as early as c. 8700–8000 14 C yr BP (c. 9700–8800 cal. yr BP), as these groups were fairly flexible and resilient in dealing with short-term shortages of water.Fil: Martinez, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Gutierrez, Maria Amelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; Argentin

Numerical analysis in interrupted cutting tool temperatures

In any cutting process, plastic deformation involved in chip formation and friction between the tool and the workpiece produces heat by the conversion of mechanical energy. A portion of this heat conducts into the tool and results in high temperatures near the cutting edge. As the temperature increases, the tool becomes softer and wears more rapidly, thus having a negative impact on tool life. In many cutting processes, tool life, or tool wear, is the major limitation to the process viability. Increased temperature also affects the dimensional accuracy of the products and machining efficiency. Because of these considerations, it is crucial to be able to predict accurately the tool temperature. Cutting temperatures have been studied widely for a number of years. Most research, however, has been restricted to steady state temperatures in relatively simple processes, such as orthogonal cutting or cylindrical turning, in which the cutting speed, feed rate, and the depth of cut are constant [1^3, 17, 21, 24]. In most industrial machining processes, however, these parameters vary with time so that a steady state temperature assumption may not be valid

Numerical analysis of the convective heat transfer in a combustor cooling jacket

Abstract: In any combustors and chemical reactors, to achieve high efficiency it is very important to maintain the high gas temperature inside the combustion chamber without significant deterioration of the materials of the walls. Thus, a critical aspect of the design of a combustor or reactor is the development of a method to cool the inner walls of a combustor such that the temperatures on the inner wall are well below the temperature a material can sustain. A typical method to cool a combustor chamber is to use a cooling jacket adjacent to the inner wall of the combustor. In general, the efficiency of this cooling jacket depends on the heat removal capability of the cooling water and the flow channel geometry. It is critically important to control these parameters to enhance the performance of the combustion chamber by decreasing the inner wall temperature below its material limit Sφ : source term in the generic property φ Vr ,Vθ , Vz : reduced velocities in the r, θ , and z direction respectively [m/s] T : temperature [ºC] Tinn : inner temperature [ºC] T∞ : ambient temperature [ºC] U0 : inlet velocity [m/s] Greek ρ : density [kg/m3] φ : generic property μ : dynamic viscosity [kg/m-s] Γ : diffusivity for the generic property φ Ω : angular velocity [rad/s] This study considers a cylindrical combustor, rotating around its axis. A detailed investigation of the fluid flow and heat transfer processes throughout the cooling jacket is performed. A two-dimensional axial symmetric Navier-Stokes equations and energy equation as a conjugate problem are solved. The flow patterns and temperature distributions of the cooling jacket under the effect of rotation are presented. Also, local friction factor and Nusselt number are calculated along the axial direction

Analysis of the failure of cracked biscuits

Cracks or checks in biscuits weaken the material and cause the product to break at low load levels that are perceived as injurious to product quality. In this work, the structural response of circular digestive biscuits, with diameter 72 mm and thickness 7.2 mm, simply supported around the circumference and loaded by a central concentrated force was investigated by experiment and theory. Tests were conducted to quantify the distribution in breakage strength for structurally sound biscuits, biscuits with natural checks and biscuits with a single known part-through crack. For sound biscuits the breakage force is Normally distributed with a mean of 12.5 N and standard deviation of 1.2 N. For biscuits with checks, the corresponding statistics are 9.6 N ± 2.62 N respectively. The presence of a crack weakens the biscuit and strength, as measured by breakage force falls almost linearly with crack length and crack depth. The orientation of the crack, whether radial or tangential, and its location (i.e. position of the crack mid-point on the biscuit surface) are also important. Deep, radial, cracks located close to the biscuit centre can reduce the strength by up to 50%. Two separate failure criteria were examined for sound and cracked biscuits respectively. The results from these tests were in good accord with theory. For a biscuit without defects, breakage occurred when maximum biscuit stress reached or exceeded the failure stress of 420 kPa. For a biscuit with cracks, breakage occurred as above or alternatively when its critical stress intensity factor of 18 kPam0.5 was reached