Centrifuge modeling of earth-reinforced retaining walls

Object of this thesis has been centrifuge modelling of earth reinforced retaining walls with modular blocks facing in order to investigate on the influence of design parameters, such as length and vertical spacing of reinforcement, on the behaviour of the structure. In order to demonstrate, 11 models were tested, each one with different length of reinforcement or spacing. Each model was constructed and then placed in the centrifuge in order to artificially raise gravitational acceleration up to 35 g, reproducing the soil behaviour of a 5 metre high wall. Vertical and horizontal displacements were recorded by means of a special device which enabled tracking of deformations in the structure along its longitudinal cross section, essentially drawing its deformed shape. As expected, results confirmed reinforcement parameters to be the governing factor in the behaviour of earth reinforced structures since increase in length and spacing improved structural stability. However, the influence of the length was found out to be the leading parameter, reducing facial deformations up to five times, and the spacing playing an important role especially in unstable configurations. When failure occurred, failure surface was characterised by the same shape (circular) and depth, regardless of the reinforcement configuration. Furthermore, results confirmed the over-conservatism of codes, since models with reinforcement layers 0.4H long showed almost negligible deformations. Although the experiments performed were consistent and yielded replicable results, further numerical modelling may allow investigation on other issues, such as the influence of the reinforcement stiffness, facing stiffness and varying backfills.

System Engineering Approach to Initial Design of LEO Remote Sensing Missions

The satellite remote sensing missions are essential for long-term research around the condition of the earth resources and environment. On the other hand, in recent years the application of microsatellites is of interest in many space programs for their less cost and response time. In microsatellite remote sensing missions there are tight interrelations between different requirements such as orbital altitude, revisit time, mission life and spatial resolution. Also, all of these requirements can affect the whole system level design characteristics. In this work, the remote sensing microsatellite sizing process is divided into three major design disciplines; a) orbit design, b) payload sizing and c) bus sizing. Finally, some specific design cases are investigated inside the design space for evaluating the effect of different design variables on the satellite total mass. Considering the results of the work, it is concluded that applying a systematic approach at the initial design phase of such projects provides a good insight to the not clearly seen interactions inside their highly extended design space

Introduction to Special issue on the Symposium on the Application of Neural Networks to the Earth Sciences

Papers in this issue of Natural Resources Research are from the “Symposium on the Application of Neural Networks to the Earth Sciences,” held 20–21 August 2002 at NASA Moffet Field, Mountain View, California. The Symposium represents the Seventh International Symposium on Mineral Exploration (ISME-02). It was sponsored by the Mining and Materials Processing Institute of Japan (MMIJ), the US Geological Survey, the Circum-Pacific Council, and NASA. The ISME symposia have been held every two years in order to bring together scientists actively working on diverse quantitative methods applied to the earth sciences. Although the title, International Symposium on Mineral Exploration, suggests exclusive focus on mineral exploration, interests and presentations always have been wide-ranging—talks presented at this symposium are no exception.

Using biomimicry to inform urban infrastructure design that addresses 21st century needs

The design of society’s major infrastructure systems are generally based on anthropogenic learnings and seldom encapsulate learning from nature. This results from a pervading attitude of superiority of human-designed systems, particularly since the Industrial Revolution. Problems created by such behaviours have previously not been thought to present a serious threat to humanity. However, many built environment professionals are now reconsidering the impact of such systems on the environment and their vulnerability to issues such as climate change. This paper presents an approach to delivering sustainable urban infrastructure that addresses 21st Century needs by emulating natural form, function and process - biomimicry – in infrastructure design. The analysis reveals the context for infrastructure change and the need for sustainable solutions, detailing the current inquiry into biomimicry informed design and highlighting potential applications from literature that demonstrate precedence for nature to inspire the design of urban infrastructure, in particular water and energy systems.

Stabilization of experimental bioretention basins during intermittent wetting and drying

Stormwater bioretention basins are subjected to spontaneous intermittent wetting and drying, unlike water treatment filter systems that are subjected to continuous feed. Drinking water filters when constructed new or after back-wash, are subjected to a phase of stabilization. Experiments show that bioretention basins are similarly impacted by intermittent wetting and drying. The common parameter monitored in the stabilisation of filters is the concentration of total solids in the outflow. Filter media in bioretention basins however, consists of a mix of particulate organic matter and fine sand. Organic carbon and solids are therefore needed to be monitored. Four Perspex bioretention filter columns of 94 mm (ID) were packed with a filter layer (800 mm), transition layer and a gravel layer and operated with synthetic stormwater in the laboratory. The filter layer contained 8% organic material by weight. A free board of 350 mm provided detention storage and head to facilitate infiltration. Synthetic stormwater was prepared by adding NH4NO3 (ammonium nitrate) and C2H5NO2 (glycine) and a mixture of kaolinite and montmorillonite clay, to tapwater. The columns were fed with synthetic stormwater with different Antecedent Dry Days (ADD) (0 – 25 day) and constant inflow concentration (2 ppm: nitrate-nitrogen, 1.5 ppm: ammonium-nitrogen, 2.5 ppm: organic-nitrogen 100 ppm: total suspended solids and 7 ppm: organic carbon) at a feed rate of 100mL.min (85.7cm/h). Samples were collected from the outflow at different time intervals between 2 – 150 min from the start of outflow and were tested for Total Suspended Solids (TSS) and Total Organic Carbon (TOC). Both TSS and TOC concentrations in the outflow were observed to be much higher than the concentration of both the parameters in the inflow during the stabilisation period indicating a phase of wash-off (first flush) which lasted for approximately 30 min for both parameters at the beginning of each storm event. The wash-off of TSS and TOC were found to be highly variable depending on the age of the filter and the number of antecedent dry days. The duration of stabilisation phase in the experiments is significant compared with many of the stormwater events. A computational analysis on total mass of each pollutant further affirmed the significance of the first flush of an event on removal of these pollutants. Therefore, the kinetics of the first flush in the stabilisation phase needs to be considered in the performance analysis of the systems.

Barriers, drivers and enablers for transitioning towards innovation in the Australian water sector

The Australian water sector needs to adapt to effectively deal with the impacts of climate change on its systems. Challenges as a result of climate change include increasingly extreme occurrences of weather events including flooding and droughts (Pittock, 2011). In response to such challenges, the National Water Commission in Australia has identified the need for the water sector to transition towards being readily adaptable and able to respond to complex needs for a variety of supply and demand scenarios (National Water Commission, 2013). To successfully make this transition, the sector will need to move away from business as usual, and proactively pursue and adopt innovative approaches and technologies as a means to successfully address the impacts of climate change on the Australian water sector. In order to effectively respond to specific innovation challenges related to the sector, including climate change, it is first necessary to possess a foundational understanding about the key elements related to innovation in the sector. This paper presents this base level understanding, identifying the key barriers, drivers and enablers, and elements for innovative practise in the water sector. After initially inspecting the literature around the challenges stemming from climate change faced by the sector, the paper then examines the findings from the initial two rounds of a modified Delphi study, conducted with experts from the Australian water sector, including participants from research, government and industry backgrounds. The key barriers, drivers and enablers for innovation in the sector identified during the initial phase of the study formed the basis for the remainder of the investigation. Key elements investigated were: barriers – scepticism, regulation systems, inconsistent policy; drivers – influence of policy, resource scarcity, thought leadership; enablers – framing the problem, effective regulations, community acceptance. There is a convincing argument for the water sector transitioning to a more flexible, adaptive and responsive system in the face of challenges resulting from climate change. However, without first understanding the challenges and opportunities around making this transition, the likelihood of success is limited. For that reason, this paper takes the first step in understanding the elements surrounding innovation in the Australian water sector.

On-Farm Flood Flow Capture – addressing flood risks and groundwater overdraft in the Kings Basin, with potential applications throughout the Central Valley

Project fact sheet prepared in cooperation with the USDA Natural Resources Conservation Service and the Kings River Conservation District.

Unscented Kalman Filter Applied to the Spacecraft Attitude Estimation with Euler Angles

The aim of this work is to test an algorithm to estimate, in real time, the attitude of an artificial satellite using real data supplied by attitude sensors that are on board of the CBERS-2 satellite (China Brazil Earth Resources Satellite). The real-time estimator used in this work for attitude determination is the Unscented Kalman Filter. This filter is a new alternative to the extended Kalman filter usually applied to the estimation and control problems of attitude and orbit. This algorithm is capable of carrying out estimation of the states of nonlinear systems, without the necessity of linearization of the nonlinear functions present in the model. This estimation is possible due to a transformation that generates a set of vectors that, suffering a nonlinear transformation, preserves the same mean and covariance of the random variables before the transformation. The performance will be evaluated and analyzed through the comparison between the Unscented Kalman filter and the extended Kalman filter results, by using real onboard data.

Multidisciplinary Design Optimization Application to Conceptual Design of University-class Microsatellite Projects

Esta tesis se ha realizado en el contexto del proyecto UPMSat-2, que es un microsatélite diseñado, construido y operado por el Instituto Universitario de Microgravedad "Ignacio Da Riva" (IDR / UPM) de la Universidad Politécnica de Madrid. Aplicación de la metodología Ingeniería Concurrente (Concurrent Engineering: CE) en el marco de la aplicación de diseño multidisciplinar (Multidisciplinary Design Optimization: MDO) es uno de los principales objetivos del presente trabajo. En los últimos años, ha habido un interés continuo en la participación de los grupos de investigación de las universidades en los estudios de la tecnología espacial a través de sus propios microsatélites. La participación en este tipo de proyectos tiene algunos desafíos inherentes, tales como presupuestos y servicios limitados. Además, debido al hecho de que el objetivo principal de estos proyectos es fundamentalmente educativo, por lo general hay incertidumbres en cuanto a su misión en órbita y cargas útiles en las primeras fases del proyecto. Por otro lado, existen limitaciones predeterminadas para sus presupuestos de masa, volumen y energía, debido al hecho de que la mayoría de ellos están considerados como una carga útil auxiliar para el lanzamiento. De este modo, el costo de lanzamiento se reduce considerablemente. En este contexto, el subsistema estructural del satélite es uno de los más afectados por las restricciones que impone el lanzador. Esto puede afectar a diferentes aspectos, incluyendo las dimensiones, la resistencia y los requisitos de frecuencia. En la primera parte de esta tesis, la atención se centra en el desarrollo de una herramienta de diseño del subsistema estructural que evalúa, no sólo las propiedades de la estructura primaria como variables, sino también algunas variables de nivel de sistema del satélite, como la masa de la carga útil y la masa y las dimensiones extremas de satélite. Este enfoque permite que el equipo de diseño obtenga una mejor visión del diseño en un espacio de diseño extendido. La herramienta de diseño estructural se basa en las fórmulas y los supuestos apropiados, incluyendo los modelos estáticos y dinámicos del satélite. Un algoritmo genético (Genetic Algorithm: GA) se aplica al espacio de diseño para optimizaciones de objetivo único y también multiobjetivo. El resultado de la optimización multiobjetivo es un Pareto-optimal basado en dos objetivo, la masa total de satélites mínimo y el máximo presupuesto de masa de carga útil. Por otro lado, la aplicación de los microsatélites en misiones espaciales es de interés por su menor coste y tiempo de desarrollo. La gran necesidad de las aplicaciones de teledetección es un fuerte impulsor de su popularidad en este tipo de misiones espaciales. Las misiones de tele-observación por satélite son esenciales para la investigación de los recursos de la tierra y el medio ambiente. En estas misiones existen interrelaciones estrechas entre diferentes requisitos como la altitud orbital, tiempo de revisita, el ciclo de vida y la resolución. Además, todos estos requisitos puede afectar a toda las características de diseño. Durante los últimos años la aplicación de CE en las misiones espaciales ha demostrado una gran ventaja para llegar al diseño óptimo, teniendo en cuenta tanto el rendimiento y el costo del proyecto. Un ejemplo bien conocido de la aplicación de CE es la CDF (Facilidad Diseño Concurrente) de la ESA (Agencia Espacial Europea). Está claro que para los proyectos de microsatélites universitarios tener o desarrollar una instalación de este tipo parece estar más allá de las capacidades del proyecto. Sin embargo, la práctica de la CE a cualquier escala puede ser beneficiosa para los microsatélites universitarios también. En la segunda parte de esta tesis, la atención se centra en el desarrollo de una estructura de optimización de diseño multidisciplinar (Multidisciplinary Design Optimization: MDO) aplicable a la fase de diseño conceptual de microsatélites de teledetección. Este enfoque permite que el equipo de diseño conozca la interacción entre las diferentes variables de diseño. El esquema MDO presentado no sólo incluye variables de nivel de sistema, tales como la masa total del satélite y la potencia total, sino también los requisitos de la misión como la resolución y tiempo de revisita. El proceso de diseño de microsatélites se divide en tres disciplinas; a) diseño de órbita, b) diseño de carga útil y c) diseño de plataforma. En primer lugar, se calculan diferentes parámetros de misión para un rango práctico de órbitas helio-síncronas (sun-synchronous orbits: SS-Os). Luego, según los parámetros orbitales y los datos de un instrumento como referencia, se calcula la masa y la potencia de la carga útil. El diseño de la plataforma del satélite se estima a partir de los datos de la masa y potencia de los diferentes subsistemas utilizando relaciones empíricas de diseño. El diseño del subsistema de potencia se realiza teniendo en cuenta variables de diseño más detalladas, como el escenario de la misión y diferentes tipos de células solares y baterías. El escenario se selecciona, de modo de obtener una banda de cobertura sobre la superficie terrestre paralelo al Ecuador después de cada intervalo de revisita. Con el objetivo de evaluar las interrelaciones entre las diferentes variables en el espacio de diseño, todas las disciplinas de diseño mencionados se combinan en un código unificado. Por último, una forma básica de MDO se ajusta a la herramienta de diseño de sistema de satélite. La optimización del diseño se realiza por medio de un GA con el único objetivo de minimizar la masa total de microsatélite. Según los resultados obtenidos de la aplicación del MDO, existen diferentes puntos de diseños óptimos, pero con diferentes variables de misión. Este análisis demuestra la aplicabilidad de MDO para los estudios de ingeniería de sistema en la fase de diseño conceptual en este tipo de proyectos. La principal conclusión de esta tesis, es que el diseño clásico de los satélites que por lo general comienza con la definición de la misión y la carga útil no es necesariamente la mejor metodología para todos los proyectos de satélites. Un microsatélite universitario, es un ejemplo de este tipo de proyectos. Por eso, se han desarrollado un conjunto de herramientas de diseño para encarar los estudios de la fase inicial de diseño. Este conjunto de herramientas incluye diferentes disciplinas de diseño centrados en el subsistema estructural y teniendo en cuenta una carga útil desconocida a priori. Los resultados demuestran que la mínima masa total del satélite y la máxima masa disponible para una carga útil desconocida a priori, son objetivos conflictivos. En este contexto para encontrar un Pareto-optimal se ha aplicado una optimización multiobjetivo. Según los resultados se concluye que la selección de la masa total por satélite en el rango de 40-60 kg puede considerarse como óptima para un proyecto de microsatélites universitario con carga útil desconocida a priori. También la metodología CE se ha aplicado al proceso de diseño conceptual de microsatélites de teledetección. Los resultados de la aplicación del CE proporcionan una clara comprensión de la interacción entre los requisitos de diseño de sistemas de satélites, tales como la masa total del microsatélite y la potencia y los requisitos de la misión como la resolución y el tiempo de revisita. La aplicación de MDO se hace con la minimización de la masa total de microsatélite. Los resultados de la aplicación de MDO aclaran la relación clara entre los diferentes requisitos de diseño del sistema y de misión, así como que permiten seleccionar las líneas de base para el diseño óptimo con el objetivo seleccionado en las primeras fase de diseño. ABSTRACT This thesis is done in the context of UPMSat-2 project, which is a microsatellite under design and manufacturing at the Instituto Universitario de Microgravedad “Ignacio Da Riva” (IDR/UPM) of the Universidad Politécnica de Madrid. Application of Concurrent Engineering (CE) methodology in the framework of Multidisciplinary Design application (MDO) is one of the main objectives of the present work. In recent years, there has been continuing interest in the participation of university research groups in space technology studies by means of their own microsatellites. The involvement in such projects has some inherent challenges, such as limited budget and facilities. Also, due to the fact that the main objective of these projects is for educational purposes, usually there are uncertainties regarding their in orbit mission and scientific payloads at the early phases of the project. On the other hand, there are predetermined limitations for their mass and volume budgets owing to the fact that most of them are launched as an auxiliary payload in which the launch cost is reduced considerably. The satellite structure subsystem is the one which is most affected by the launcher constraints. This can affect different aspects, including dimensions, strength and frequency requirements. In the first part of this thesis, the main focus is on developing a structural design sizing tool containing not only the primary structures properties as variables but also the satellite system level variables such as payload mass budget and satellite total mass and dimensions. This approach enables the design team to obtain better insight into the design in an extended design envelope. The structural design sizing tool is based on the analytical structural design formulas and appropriate assumptions including both static and dynamic models of the satellite. A Genetic Algorithm (GA) is applied to the design space for both single and multiobejective optimizations. The result of the multiobjective optimization is a Pareto-optimal based on two objectives, minimum satellite total mass and maximum payload mass budget. On the other hand, the application of the microsatellites is of interest for their less cost and response time. The high need for the remote sensing applications is a strong driver of their popularity in space missions. The satellite remote sensing missions are essential for long term research around the condition of the earth resources and environment. In remote sensing missions there are tight interrelations between different requirements such as orbital altitude, revisit time, mission cycle life and spatial resolution. Also, all of these requirements can affect the whole design characteristics. During the last years application of the CE in the space missions has demonstrated a great advantage to reach the optimum design base lines considering both the performance and the cost of the project. A well-known example of CE application is ESA (European Space Agency) CDF (Concurrent Design Facility). It is clear that for the university-class microsatellite projects having or developing such a facility seems beyond the project capabilities. Nevertheless practicing CE at any scale can be beneficiary for the university-class microsatellite projects. In the second part of this thesis, the main focus is on developing a MDO framework applicable to the conceptual design phase of the remote sensing microsatellites. This approach enables the design team to evaluate the interaction between the different system design variables. The presented MDO framework contains not only the system level variables such as the satellite total mass and total power, but also the mission requirements like the spatial resolution and the revisit time. The microsatellite sizing process is divided into the three major design disciplines; a) orbit design, b) payload sizing and c) bus sizing. First, different mission parameters for a practical range of sun-synchronous orbits (SS-Os) are calculated. Then, according to the orbital parameters and a reference remote sensing instrument, mass and power of the payload are calculated. Satellite bus sizing is done based on mass and power calculation of the different subsystems using design estimation relationships. In the satellite bus sizing, the power subsystem design is realized by considering more detailed design variables including a mission scenario and different types of solar cells and batteries. The mission scenario is selected in order to obtain a coverage belt on the earth surface parallel to the earth equatorial after each revisit time. In order to evaluate the interrelations between the different variables inside the design space all the mentioned design disciplines are combined in a unified code. The integrated satellite system sizing tool developed in this section is considered as an application of the CE to the conceptual design of the remote sensing microsatellite projects. Finally, in order to apply the MDO methodology to the design problem, a basic MDO framework is adjusted to the developed satellite system design tool. Design optimization is done by means of a GA single objective algorithm with the objective function as minimizing the microsatellite total mass. According to the results of MDO application, there exist different optimum design points all with the minimum satellite total mass but with different mission variables. This output demonstrates the successful applicability of MDO approach for system engineering trade-off studies at the conceptual design phase of the design in such projects. The main conclusion of this thesis is that the classical design approach for the satellite design which usually starts with the mission and payload definition is not necessarily the best approach for all of the satellite projects. The university-class microsatellite is an example for such projects. Due to this fact an integrated satellite sizing tool including different design disciplines focusing on the structural subsystem and considering unknown payload is developed. According to the results the satellite total mass and available mass for the unknown payload are conflictive objectives. In order to find the Pareto-optimal a multiobjective GA optimization is conducted. Based on the optimization results it is concluded that selecting the satellite total mass in the range of 40-60 kg can be considered as an optimum approach for a university-class microsatellite project with unknown payload(s). Also, the CE methodology is applied to the remote sensing microsatellites conceptual design process. The results of CE application provide a clear understanding of the interaction between satellite system design requirements such as satellite total mass and power and the satellite mission variables such as revisit time and spatial resolution. The MDO application is done with the total mass minimization of a remote sensing satellite. The results from the MDO application clarify the unclear relationship between different system and mission design variables as well as the optimum design base lines according to the selected objective during the initial design phases.

Mission to planet Earth.

Cover title.

Earth system science overview : a program for global change /

"May 1986."

NASA's mission to planet Earth : Earth Observing System.

Mode of access: Internet.

Successive nonparametric estimation of conditional distributions

Spatial characterization of non-Gaussian attributes in earth sciences and engineering commonly requires the estimation of their conditional distribution. The indicator and probability kriging approaches of current nonparametric geostatistics provide approximations for estimating conditional distributions. They do not, however, provide results similar to those in the cumbersome implementation of simultaneous cokriging of indicators. This paper presents a new formulation termed successive cokriging of indicators that avoids the classic simultaneous solution and related computational problems, while obtaining equivalent results to the impractical simultaneous solution of cokriging of indicators. A successive minimization of the estimation variance of probability estimates is performed, as additional data are successively included into the estimation process. In addition, the approach leads to an efficient nonparametric simulation algorithm for non-Gaussian random functions based on residual probabilities.

Geophysics: Principles, applications and emerging technologies

This book presents research in the field of Geophysics, particularly referring to principles, applications and emerging technologies. Table of Contents: Preface pp. i-xxi Environmental Geophysics: Techniques, advantages and limitations (Pantelis Soupios and Eleni Kokinou, Department of Environmental and Natural Resources Engineering, Technological Educational Institute of Crete, Dynamics of the Ocean Floor, Helmholtz Centre for Ocean Research Kiel, Geomar)pp i-xxi Application of Innovative Geophysical Techniques in Coastal Areas (V. Di Fiore, M. Punzo, D. Tarallo, and G. Cavuoto, Institute for Marine Coastal Environment, National Research Council, Naples)pp. i-xxi Marine Geophysics of the Naples Bay (Southern Tyrrhenian sea, Italy): Principles, Applications and Emerging Technologies (Gemma Aiello and Ennio Marsella, Institute for Marine Coastal Environment, National Research Council, Naples)pp. i-xxi Oceanic Oscillation Phenomena: Relation to Synchronization and Stochastic Resonance (Shinya Shimokawa and Tomonori Matsuura, National Research Institute for Earth Science and Disaster Prevention, Univ. of Toyama)pp. i-xxi Assessment of ocean variability in the Sicily Channel from a numerical three-dimensional model using EOFs decomposition (R. Sorgente, A. Olita, A.F. Drago, A. Ribotti, L. Fazioli, and C. Tedesco, Institute for Marine Coastal Environment, National Research Council, Oristano)pp. i-xxi Monitoring Test of Crack Opening in Volcanic Tuff (Coroglio Cliff. Italy) Using Distributed Optical Fiber Sensor (A. Minardo, A. Coscetta, M. Caccavale, G. Esposito, F. Matano, M. Sacchi, R. Somma, G. Zeni, and L. Zeni, Department of Industrial and Information Eng., Second University of Naples Aversa, Institute for Marine Coastal Environment, National Research Council Naples, National Institute for Geophysics and Volcanology, Osservatorio Vesuviano Naples, Institute for Electromagnetic Sensing of the Environment, National Research Council Naples)pp. i-xxi