Master of Science / Department of Architectural Engineering and Construction Science / Kimberly Waggle Kramer / Insulated precast concrete sandwich panels are commonly used for exterior cladding on a building. In recent years, insulated tilt-up concrete sandwich panels are being used for the exterior load-bearing walls on a building. The insulation is sandwiched between exterior and interior concrete layers to reduce the heating and cooling costs for the structure. The panels can be designed as composite, partially composite, or non-composite. The shear ties are used to achieve these varying degrees of composite action between the concrete layers. A parametric study analyzing the standard, solid single-wythe tilt-up concrete wall panel and solid sandwich (double-wythe separated by rigid insulation) tilt-up concrete wall panels subjected to eccentric axial loads and out-of-plane seismic loads is presented. The sandwich tilt-up panel is divided into two categories – non-composite and composite wall panels. The height and width of the different types of tilt-up wall panel is 23 feet (21 feet plus 2-foot parapet) and 16 feet, respectively. The solid standard panel (non-sandwich) is 5.5 inches in thickness; the non-composite sandwich panel is composed of 3.5-inch architectural wythe, 2.5-inch rigid insulation, and 5.5-inch interior load bearing concrete wythe; and the composite sandwich panel is composed of 3.5-inch exterior, load bearing concrete wythe, 2.5-inch insulation, and 5.5-inch interior, load bearing concrete wythe. The procedure used to design the tilt-up wall panels is the Alternative Method for Out-of-Plane Slender Wall Analysis per Section 11.8 of ACI 318-14 Building Code Requirements for Structural Concrete and Commentary. The results indicated that for the given panels, the applied ultimate moment and design moment strength is the greatest for the composite sandwich tilt-up concrete panel. The standard tilt-up concrete panel exhibits the greatest service load deflection. The non-composite sandwich tilt-up concrete panel induced the greatest vertical stress. Additionally, the additional requirements regarding forming materials, casting, and crane capacity is covered in this report. Lastly, the energy efficiency due to the heat loss and heat gain of sandwich panels is briefly discussed in this report. The sandwich tilt-up panels exhibit greater energy efficiency than standard tilt-up panels with or without insulation.

South Africa is a water-stressed country where water availability is an important constraint to economic and social development, and will become even more so in the future if this scarce resource is not managed effectively. In order to manage this scarce supply of water, we need to value it. This study focuses on the value of water in the agricultural sector, in particular the marginal revenue of water for six irrigation commodities namely avocados, bananas, grapefruit, mangoes, oranges and sugarcane. A quadratic production function was fitted with an SUR model specification in a panel data study from 1975 to 2002 to obtain marginal revenue functions for each of the six commodities. We found that mangoes are the most efficient commodity in its water use relative to revenue generated (marginal revenue of water equals R25.43/m³ in 2002) and sugarcane the least efficient (marginal revenue of water equals R1.67/m³ in 2002). The marginal revenue of water is not an indication of the true “market” price. Neither is it an indication what the administered price should be. The marginal revenue of water is rather a guideline for policy makers to determine which industries or commodities within an industry can generate the largest revenue per unit water applied. / Dissertation (MCom (Econometrics))--University of Pretoria, 2006. / Economics / unrestricted

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El presente trabajo de investigación se enmarca en la Teoría económica del crecimiento económico y tiene como objetivo central identificar a sus determinantes dentro del marco de la apertura comercial, para lo cual se toma como muestra a los países de Latinoamérica que cuenten con información disponible y factible de comparación, entre 1950 y 2014. En base a ello, se plantea como tema de investigación: ¿cómo influyó la apertura comercial en el crecimiento económico de Perú y Latinoamérica entre los años 1950 y 2014? / Tesis

Blast risk associated with terrorist threats and accidental explosions has become an international concern over the past decade and has provoked structural engineers to implement protective design measures. Recent advances in this area of research has seen tremendous improvements in mitigating this risk through the installation of retrofits, advanced structural design, or pre-emptive protective measures. Tilt-up and precast panel walls are constructed using a unique approach in which the walls are cast horizontally and lifted, or tilted, into their final vertical position. These unique structures are cost effective, energy efficient, and can be rapidly constructed. This approach is commonly applied to the construction of large industrial facilities and the construction of schools which are categorized as high importance structures in the National Building Code of Canada. These panels are inherently flexible and have a surplus of mass making them desirable for protective design applications, however their behaviour under blast induced loads is not well defined. This experimental research project investigates the behaviour of non-composite tilt-up sandwich (NCTS) panels and solid reinforced concrete (SRC) panels with realistic support conditions subjected to blast-induced shockwaves. Previous research shows that NCTS panels, identifiable by their large structural wythe, exhibit some degree of composite behaviour and require between 5% to 10% composite action for successful erection. Five scaled specimens were constructed following common procedures used in practice, equipped with identical data acquisition instruments, and tested at the University of Ottawa shock tube testing facility under similar blast pressure-impulse combinations. Test results for the NCTS and SRC panels are compared graphically in terms of displacement–time histories and sectional strain distributions. The data is evaluated to approximate the composite behaviour at mid-span of the NCTS panel. Analytical results generated, using “RC Blast,” single-degree-of-freedom analysis software developed at the University of Ottawa, were validated with empirical data and are presented graphically. Each specimen was equipped with connections similar to those commonly used in the construction of NCTS panels. These connections were experimentally studied under simulated blast pressures and analysed using CSA A23.3-04 guidelines for punching shear capacity. Modified support iii | P a g e reinforcement layouts and surface bonded FRP laminates were evaluated as strengthening and retrofit techniques to prevent support failure. Dynamic support reactions and predicted support resistances are tabulated for each shot of every panel. The results indicate that it is possible to accurately predict the flexural behaviour and support resistance of a NCTS panel using RC Blast and CSA A23.3-04 guidelines. Several factors considered in this analysis include boundary conditions, dynamic material properties, and shear tie degradation. This analysis of flexural behaviour is highly dependent on shear stiffness, which is directly related to the composite action within NCTS panels. Support resistance was increased significantly through application of the strengthening techniques outlined in this thesis.

The thesis focuses on the design of hardware and software prototype of adaptive automotive rear-lighting. Hardware includes a control module and LED module with 150 high brightneess light emitting diodes. These diodes are serve as an adaptive backlight for color LCD display. The device Raspberry Pi 3 was selected as the control element. This device insludes the support of all communications buses which are used in this thesis.

This thesis is focused on the design of panel antennas for band 5,6 GHz. Antennas have been examined and optimized with a view to impedance, broadband and directional characteristics by using designing software CST Design Environment. Optimized antennas were produced, and their measured parameters achieved required values.

Autor no autoriza el acceso a texto completo de su documento hasta el 31/8/2020. / Ingeniero Civil de Minas / El fracturamiento hidráulico (FH) es utilizado para preacondicionar el macizo rocoso para facilitar la propagación del caving en métodos de explotación subterránea por hundimiento y disminuir las dimensiones de los bloques de mineral formados. Esto se logra aumentando el número de discontinuidades existentes inyectando agua a altas presiones produciendo fracturas por tracción, las que se orientan de manera perpendicular al esfuerzo principal menor. Sin embargo, las mejores condiciones se obtienen cuando estas resultan horizontales, por lo que es necesario comprender el comportamiento de los esfuerzos para desarrollar el FH de la mejor manera posible evitando que se inclinen. Una forma de lograr esto es a través del modelamiento numérico y la correlación de sus resultados con datos empíricos. El trabajo presentado en este informe utiliza el software Phase2 para identificar el efecto de distintos parámetros de la geometría (ángulo de desplome, ángulo de extracción y socavación) generada al explotar un yacimiento a través de Panel Caving con herramientas de modelamiento numérico e implementar este conocimiento para proponer una metodología que permita estimar la forma de la cavidad que se produce con este método de explotación en función de los registros de propagación media de las distintas fracturas desarrolladas por pozo de FH. Al analizar los resultados obtenidos es posible concluir que a mayores ángulos de desplome, mayores son los esfuerzos delante del frente de socavación por existir una mayor cantidad de roca soportada por este sector. Además el análisis de esta variable permite notar que la zona más cercana a la cavidad se encuentra desconfinada, por lo que se necesitan menores presiones para fracturar el macizo. En cuanto a la socavación y ángulo de extracción, el efecto que generan es similar, produciendo perfiles más cóncavos con esfuerzos menores en la parte superior del pozo y valores notablemente mayores en la sección inferior de estos porque se produce una concentración de esfuerzos delante del frente de socavación. Para el análisis del ángulo extracción se pudo notar que éste debe estar presente en el modelo al igual que la socavación, aunque el valor que se use entre los rangos estudiados no es muy relevante ya que las variaciones producidas en el comportamiento del esfuerzo principal menor son muy leves y no justifican la elaboración de nuevos modelos. La metodología propuesta entrega valores bastante satisfactorios para los dos pozos utilizados para verificarla, resultando en perfiles que se comportaban similar a los registros de presiones en especial en la parte superior de los tiros. En base a esto, se considera que es una buena herramienta para complementar otros métodos de estimación o para obtener una aproximación cuando no existan medios distintos que se puedan usar, sobre todo al considerar que se trata de representaciones muy simplificadas que no presentan grandes dificultades para generarlas y poder analizarlas posteriormente. El trabajo que se presenta abre a su vez opciones para llevar el estudio más adelante e identificar si es posible que los ajustes sean mejores. Para esto se propone incorporar elementos que por simplificación fueron dejados de lado en este trabajo e incluso desarrollar una nueva metodología utilizando modelos en tres dimensiones.

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