Experimental Study of High-Speed Boats with Suspended Flaps for Reducing the Slamming Forces

This thesis consists of two parts. In the first part a small-scale high-speed monohull boat was fitted with a suspended flap under the bottom. The author tested shock absorbers for this boat, and worked on data analysis from a few initial test runs. The boat tests were performed during a few hours in a single day and the data are far too scarce to draw any conclusions. The second part of the thesis concerns multi-body numerical analysis of a suspension boat that consists of an airborne centerhull and four suspended sponsons. No simulations of boat dynamics in waves were performed. First, a brief overview of slamming problem and techniques used to reduce the vertical acceleration was conducted, full description of proposed mechanism and the instruments used to evaluate the boat behavior equipped with the mechanism, then boat testing and data analysis was illustrated. Second, advanced dynamic numerical model for the suspension boat with four sposons was developed

Evaluation of soil extraction methods for uranium

Uran (U) ist unter natürlichen Bedingungen in Böden in sehr geringer Konzentration vorhanden. Nach den United Nations umfasst der Bereich der möglichen U-Bodenkonzentrationen 0,3 bis 11,7 mg kg-1. Das Verhalten von U im Boden ist sehr komplex, da U in verschiedenen Verbindungen und Phasen vorkommt. Nur wenig Literatur ist veröffentlicht, die sich mit der U-Bioverfügbarkeit selbst und den Einflussfaktoren auf die Bioverfügbarkeit im Boden befasst. Ein besseres Verständnis dieser Prozesse ist Voraussetzung, um passende Extraktionsverfahren zu finden, die die Bioverfügbarkeit von U in kontaminierten Böden bestmöglich abbilden. Das Hauptziel der vorliegenden Arbeit war es, U-Extraktionsverfahren aus herkömmlichen Schwermetallextraktionsverfahren zu evaluieren und diese hinsichtlich ihres Extraktionspotentials zu vergleichen. Im Ergebnis sollte das beste Verfahren für die Vorhersage der U-Pflanzenaufnahme aufgezeigt und die wichtigsten Parameter, die die Bioverfügbarkeit von U für Pflanzen in unterschiedlich U-kontaminierten Böden beeinflussen, bestimmt werden. Die Arbeit wurde am Institut für Pflanzenernährung und Bodenkunde (PB) der Bundesforschungsanstalt für Landwirtschaft (FAL) in Braunschweig, Deutschland, durchgeführt. Vier Gruppen von Bodenproben wurden untersucht, die den weiten Bereich praktisch möglicher U-Konzentrationen abdecken. Die erste Bodenprobengruppe wurde aus einem vorherigen Gefäßversuch von Rivas (2005) gewonnen; die zweite Probengruppe aus einem Inkubationsversuch unter anaeroben Verhältnissen (Lamas et al., 2005b), die dritte stammte aus einer Bergbauregion in Schneeberg (Sachsen, Deutschland) und die letzte Gruppe von Bodenproben entstammte Böden von zwei P-Dauerdüngungsversuchen (Freising und Braunschweig, Deutschland). Die Bioverfügbarkeit von U wurde mittels vier verschiedener Extraktionsmethoden untersucht, die sich in ihrem Extraktionspotential unterschieden. Für die Extraktion wurden AAAc-EDTA bei pH 4,65, 1N NH4Ac bei pH 7,0, DTPA bei pH 7,3, sowie die durch Zentrifugation gewonnene Bodenlösung (20 min bei 7.000 U/min) eingesetzt. Die Hauptergebnisse der Arbeit werden im Folgenden vorgestellt:1. Die Arbeit zeigte, dass die U-Löslichkeit eine Funktion der Stärke der Extraktionslösung ist. Die Extraktionsergebnisse von AAAc-EDTA, NH4Ac, DTPA und Bodenlösung variierten für U in Abhängigkeit von der Herkunft der Bodenproben. Die AAAc-EDTA-Lösung erzielte die besten Ergebnisse, gefolgt von NH4Ac und DTPA, wenn die Konzentration von löslichem U im Boden sehr gering war. Generell war AAAc-EDTA allen anderen Extraktionsmitteln überlegen. Vermutlich liegt das an dem enthaltenen Cheliermittel (EDTA).2. Die Versuche zeigten, dass Mais im Vergleich zu Sonnenblume und Ackerbohne ein geringeres Potential hat, aufgenommenes U über die Wurzel wieder in den Boden abzugeben. Das Wurzelsystem der dikotylen Sonnenblume und Ackerbohne kann mehr U in den Boden abgeben als die Wurzeln der monokotylen Pflanze Mais.3. Es ist in der Studie aufgezeigt worden, dass die Vorhersage der U-Aufnahme pflanzenartenabhängig ist. Für die Vorhersage der U-Aufnahme von Mais aus Ukontaminierten Böden ist AAAc-EDTA das geeignetste Extraktionsmittel, gefolgt von NH4Ac. Bei Sonnenblumen eignet sich DTPA, gefolgt von AAAc-EDTA am besten. Keines der geprüften Extraktionsmittel ermöglichte eine zutreffende Vorhersage für U-Aufnahme von Ackerbohnen. Mit keinem der vier Extraktionsmittel konnten Ergebnisse erzielt werden, die zuverlässig eine Beziehung zwischen dem aus dem Boden extrahierbaren U und der U-Konzentration im Blattund Stängelgewebe der drei Kulturpflanzen darstellen.4. Die absolute U-Konzentration im Boden ist der Haupteinflussfaktor auf die Bioverfügbarkeit von U im Boden. Hochsignifikante Korrelationskoeffizienten wurden bei dem Vergleich von U im Boden und der extrahierbaren U-Menge gefunden. Dies konnte in den meisten Bodenproben bewiesen werden.5. Die U-Extrahierbarkeit variiert mit dem Boden-pH, wie anhand der Bodenproben aus einem Gefäßversuch gezeigt werden konnte. Bei dem Boden aus Sachsen bestand eine positive Korrelation zwischen Boden-pH und extrahierbarem U bei allen vier Extraktionsmitteln.6. Die Phosphor (P)-Konzentration im Boden hatte abhängig von der Probenherkunft unterschiedliche Einflüsse auf die Bioverfügbarkeit von U. Vergleichbar war der Einfluss des Gehaltes an löslichem P im Boden.7. Die Studie zeigte zudem den Einfluss von organischer Substanz auf die UBioverfügbarkeit. Der organisch gebundene Kohlenstoff im Boden des Langzeitversuches hat einen nicht-signifikanten negativen Effekt bei AAAc-EDTA und DTPA-Extraktion. NH4Ac verhält sich nicht-signifikant positiv. Das kann bedeuten, dass U an Humuskomplexen im Boden gebunden wird, die nur NH44Ac lösen kann. Es zeigte sich, dass verschiedene Formen von organischem Material im U-kontaminierten Boden Einfluss auf die Bioverfügbarkeit von U haben.8. Die Ergebnisse der Untersuchungen zeigen, dass die U-Verfügbarkeit im Boden zeit- und pflanzenartabhängig ist. Im Rahmen dieser Arbeit konnte jedoch kein sicherer Trend für den zeitlichen Effekt der U-Bioverfügbarkeit abgeleitet werden.9. Bei N- und S-Düngung gab es keine Beziehung zur extrahierten U-Menge.10. P-Verbindungen haben Einfluss auf Schwermetalle im Boden. Die Auswertung der Langzeitversuche zeigte, dass der Gesamt-P-Gehalt im Boden hoch signifikant mit U, Cd und Ni korreliert. Vermutlich liegt es an der vorhandenen Schwermetallkonzentration im P-Dünger. Dies wurde ebenfalls im Boden aus Sachsen gefunden und es zeigten sich enge Korrelationen zwischen U, Cd und P.11. Zwischen dem Gesamt-S-Gehalt im Boden und den gemessenen Gesamt-U-, Cd-, Pb und Ni- Konzentrationen wurde eine enge Beziehung nachgewiesen.12. Organische Kohlenstoffgehalte im Boden haben einen größeren Einfluss auf Schwermetalle wie Pb und Ni als auf U. Pb ist im Gegensatz zu Ni an organisches Material gebunden (positive Korrelation bei Pb, negative bei Ni). Keinerlei Korrelationen bestanden mit Cd im Boden. Die Ergebnisse legen nahe, dass zukünftige Arbeiten zu dieser Thematik größeres Augenmerk auf Beziehungen zwischen verschiedenen U-Gehalten im Boden und der U-Extrahierbarkeit unter Berücksichtigung unterschiedlicher Bodencharakteristika gelegt werden sollte. Keines der in dieser Arbeit untersuchten Extraktionsmittel erwies sich als bevorzugt geeignet, die U-Aufnahme durch Pflanzen aus kontaminierten Böden verlässlich vorauszusagen.Normally, U is present in most soils at very low concentrations. According to the United Nations, the normal concentration of U in soils is within the range of 0.3 - 11.7 mg kg-1. The U behavior in soils is very complicated, this because U can be associated with numerous compounds and phases and many factors affect its behavior in soil. Few investigations have been published assessing the U bioavailability and the factors affecting the U bioavailability in soils. Better understanding of different factors governing the U behavior in soils is very useful because it leads to the best possible extraction procedures and the best remediation treatments in U-affected soils. The main goals of the present work were to evaluate the extractability of U from soil samples assessed by common heavy metal extractants, and compare the differences in the extractability potential between them. Also to find out which of these extractants best predict the plant uptake and concentration of U. And finally to study some of the most important factors affecting the U bioavailability for plants in a wide range of U contaminated soils. This research work was carried out at the Institute of Plant Nutrition and Soil Science (PB), Federal Agricultural Research Centre (FAL), Braunschweig, Germany. Four soil sample groups were collected covering a wide range of U concentration in soils. The first group of these samples was derived from a previously conducted greenhouse experiment by Rivas (2005). The second soil samples group was derived from a previously conducted incubation experiment under anaerobic conditions carried out by Lamas et al. (2005b). The third soil samples group was collected from the mining area of Schneeberg at the state of Saxony, Germany. The last soil samples group was collected from long term P fertilization experiments located at two sites in Braunschweig and Freising, Germany. Bioavailable U was determined using four extraction methods, which varied with respect to their extraction potential. Extractants used were: acid ammonium acetate-EDTA (AAAc-EDTA) at pH 4.65, 1N ammonium acetate (NH4Ac) at pH 7.0, diethylene triamine pentaacetic acid (DTPA) at pH 7.3 and soil solution obtained by centrifugation (7,000 rpm for 20 min). Special emphasis was paid to the extraction of soil solution via centrifugation technique. The most important findings of the research work presented here were:1- The results of the present research work demonstrated that the U solubility was found to be a function of the extraction solution. The AAAc-EDTA, NHsub>4Ac, DTPA and soil solution extractants had different capabilities to extract U from soil. The AAAc-EDTA extractant was usually the most powerful extractant in most soil samples tested here with few exceptions, followed by NHsub>4Ac and then DTPA while the concentration of soluble U in the soil solution was very low. Generally, the AAAc-EDTA extractant was definitely superior to the other extractants; this may be attributed to the presence of chelating agent (EDTA) in this extractant.2- The results revealed that the maize has a lower ability to release U into the soil in all U levels after the growth than sunflower and faba bean and this observation is well in accordance with the literature. This may be attributed to fact that dicot roots (like sunflower and faba bean) release more U in the soil from its compounds than monocot roots (like maize).3- The results of the present study implied that the prediction of U bioavailability for plant via the extraction of U from soil is a plant dependent. The AAAc-EDTA was the best predictor for maize U-uptake followed by NHsub>4Ac. The DTPA and AAAc-EDTA extractants were the best indicators for the U-uptake by sunflower plants. None of the tested extractants was able to predict the U-uptake by faba bean plants. On the other hand, none of the four extractions were able to predict the plant U concentration of any of the three crops tested here.4- The total U concentration in the soil is one of the most important factors affecting the extractability of U assessed by the four extractants used in this study. Highly significant and significant correlation coefficients r were found between the total U in soil and the extractable U with the four extractants from soil. This phenomenon was true in most of the soil samples tested here with few exceptions.5- Soil pH has various effects on the U extractability, a diverse effect of soil pH on the extractable U in soil was found in greenhouse experiment soil samples. The intensity of the effect of soil pH is dependent on the plant cultivated in the soil. In both soil samples of the incubation and long-term experiments, the effect of soil pH on the extractability of U in the soil was negligible. Positive correlations were found between soil pH and the U extracted by any of the extractants in all Saxony samples.6- Like the effect of soil pH, the results revealed that the presence of P compounds in soil had an inconsistent effect on mobility of U in soil. The total P concentration in soil had a diverse effect on the extractability of U in greenhouse soil samples. The soluble P in soil solution of maize soil samples also had the same trend. Contrary to these findings, the effect of soil P on the extractability of U in Saxony soil samples was positive. The extractable U wasn’t affected significantly by soil total P in most samples of long-term trails soil.7- The results also gave important information about the effect of soil organic matter on the extractability of U in the soil. Total organic carbon (OC) in the soil of long-term trials correlated negatively, but none significantly with AAAc-EDTA and DTPA extractants. While it correlated positively, none correlated significantly with NHsub>4Ac extractant. This means that part of the U in the soil may complex with organic matter in soil, and NH4Ac could extract some of U found in organic pool, while both AAAc-EDTA and DTPA couldn’t extract this pool. The results also demonstrated that the addition of different types of organic materials (i.e., cereal straw and milled alfalfa plants) to the U contaminated soil affected vary on the availability of U.8- The results reported here implied that the effect of storage time (time since the contamination with U) is one of the most important factors affecting the availability of U in soil. The former U extractant was the more available than the current U extractant in the greenhouse experiment samples. It could be concluded that the more recently applied U was more available than the older U applied in the greenhouse experiment samples. The results also revealed that the effect of storage time on the U extractability is plant type dependent. The investigation of the effect of storage time in the incubation experiment was the opposite of that of the greenhouse experiment, and changed depending on the soil treatments. Due to these results we concluded that the effect of storage time on the U extractability for plants in the soil is not clear and better understanding of this factor is needed on the U availability.9- The other factors studied in this work had negligible effects on the extractable U. The N and S fertilization rates had weak correlations with the extractable U from soil with the four extractants in all greenhouse soil samples. Similar results were found in the long-term trial samples. The total concentration of S in soil didn’t correlate with the extractability of U in all samples of long-term soil trials.10- The presence of P compounds in the soil had an effect on the other heavy metals in the soil. The results of the long-term trials indicated that the total soil P had highly significant correlations with the total U, Cd and Ni in soil. This may be due to the addition of P fertilizers, which may be the source of these heavy metals in the soil. A similar phenomenon was found in Saxony soils, the results revealed that the U, Cd and P elements are highly correlated with each other in the soil.11- The total content of S in the soil was found to be one of the important factors affecting the heavy metals concentration rather than U in the soil, because it correlated well with the total U, Cd, Pb, Ni in the soil. This means that all of the five elements are intrinsically present in the soil matrix.12- Soil organic matter (expressed as OC in long-term samples) also impacted on the other heavy metals in the soil rather than U like Pb and Ni. The Pb was found to be complexed (positively correlated with OC) with organic matter, while Ni was not complexed (negatively correlated with OC) with organic matter in soils. On the other hand, the OC didn’t correlate with total Cd in the soil. Based on the results of the present work, it is therefore proposed that future investigations are needed for better comprehension of the behavior of U in soils with a wide range of U contamination and different soil characteristics. These investigations are also needed for better understanding of the factors affecting the extractability of U, which reflects the U bioavailability for plant in soils. A careful examination in the future of the detailed results of all investigations in the field of U should be useful in devising new soil extractants that may be of greater universal use than the extractants used in these investigations. With the limited results obtained from this research, it wasn’t possible to discover the ideal extractant for all soils with many different characteristics

Application of Treated Oil Sands Drill Cuttings Waste in Micropiles Construction

A micropile is constructed by drilling a hole, placing a steel reinforcing element, grouting it using neat cement. However, cement production consumes energy and generates carbon dioxide. Implementing waste materials in construction applications represents a sustainable solution for many waste management problems. On the other hand, oil sands drill cuttings waste represents one of the most difficult challenges for the oil sands mining sector. Reducing the amount oil sands drill cutting waste sent to landfill offers one of the best solutions for waste management. This thesis presents an innovative solution for application of treated oil sands waste (TOSW) in grout mixtures used for micropiles construction. In this study, the physical, chemical and mineralogical characteristics of the treated oil sands drill cuttings waste were investigated. Fresh and hardened properties for micropiles grouts incorporating the treated solid drill cuttings waste were evaluated. Moreover, the effects of employing these grout mixtures on micropiles cross-section, surface interface properties and axial behaviour were investigated. The results showed that incorporating up to 20% of the treated solid drill cuttings waste as a partially replacement of cement will not adversely affect the properties of the grout. On the other hand, leaching tests evidenced the reduction in the release of heavy metals from the tested mixtures compared to that of the raw waste indicating successful stabilization/solidification of such waste in the grout. In addition, it was noticed an enhancement in the grout body diameter for micropiles installed using the developed grout, while maintaining the micropile surface properties. Moreover, micropiles installed using grout incorporating a high percentage of the TOSW (up to 30%) exhibited the same axial behaviour as that of micropile installed using conventional grout. Therefore, incorporating TOSW in micropile applications has high potential for producing cost efficient micropiles along with providing a green oil sands waste management solution

Spatial modulation schemes and modem architectures for millimeter wave radio systems

The rapid growth of wireless industry opens the door to several use cases such as internet of things and device-to-device communications, which require boosting the reliability and the spectral efficiency of the wireless access network, while reducing the energy consumption at the terminals. The vast spectrum available in millimeter-wave (mmWave) frequency band is one of the most promising candidates to achieve high-speed communications. However, the propagation of the radio signals at high carrier frequencies suffers from severe path-loss which reduces the coverage area. Fortunately, the small wavelengths of the mmWave signals allow packing a large number of antennas not only at the base station (BS) but also at the user terminal (UT). These massive antenna arrays can be exploited to attain high beamforming and combining gains and overcome the path-loss associated with the mmWave propagation. In conventional (fully digital) multiple-input-multiple-output (MIMO) transceivers, each antenna is connected to a specific radio-frequency (RF) chain and high resolution analog-to-digital-converter. Unfortunately, these devices are expensive and power hungry especially at mmWave frequency band and when operating in large bandwidths. Having this in mind, several MIMO transceiver architectures have been proposed with the purpose of reducing the hardware cost and the energy consumption. Fully connected hybrid analog and digital precoding schemes were proposed in with the aim of replacing some of the conventional RF chains by energy efficient analog devices. These fully connected mapping requires many analog devices that leads to non-negligible energy consumption. Partially connected hybrid architectures have been proposed to improve the energy efficiency of the fully connected transceivers by reducing the number of analog devices. Simplifying the transceiver’s architecture to reduce the power consumption results in a degradation of the attained spectral efficiency. In this PhD dissertation, we propose novel modulation schemes and massive MIMO transceiver design to combat the challenges at the mmWave cellular systems. The structure of the doctoral manuscript can be expressed as In Chapter 1, we introduce the transceiver design challenges at mmWave cellular communications. Then, we illustrate several state of the art architectures and highlight their limitations. After that, we propose scheme that attains high-energy efficiency and spectrum efficiency. In chapter 2, first, we mathematically describe the state of the art of the SM and highlight the main challenges with these schemes when applied at mmWave frequency band. In order to combat these challenges (for example, high cost and high power consumption), we propose novel SM schemes specifically designed for mmWave massive MIMO systems. After that, we explain how these schemes can be exploited in attaining energy efficient UT architecture. Finally, we present the channel model, systems assumptions and the transceiver devices power consumption models. In chapter 3, we consider single user SM system. First, we propose downlink (DL) receive SM (RSM) scheme where the UT can be implemented with single or multiple radio-frequency chains and the BS can be fully digital or hybrid architecture. Moreover, we consider different precoders at the BS and propose low complexity and efficient antenna selection schemes for narrowband and wideband transmissions. After that, we propose joint uplink-downlink SM scheme where we consider RSM in the DL and transmit SM (TSM) in the UL based on energy efficient hybrid UT architecture. In chapter 4, we extend the SM system to the multi-user case. Specifically, we develop joint multi-user power allocation, user selection and antenna selection algorithms for the broadcast and the multiple access channels. Chapter 5 is presented for concluding the thesis and proposing future research directions.Considerando los altos requerimientos de los servicios de nueva generación, las infraestructuras de red actual se han visto obligadas a evolucionar en la forma de manejar los diferentes recursos de red y computación. Con este fin, nuevas tecnologías han surgido para soportar las funcionalidades necesarias para esta evolución, significando también un gran cambio de paradigma en el diseño de arquitecturas para la futura implementación de redes.En este sentido, este documento de tesis doctoral presenta un análisis sobre estas tecnologías, enfocado en el caso de redes inter/intra Data Centre. Por consiguiente, la introducción de tecnologías basadas en redes ópticas ha sido estudiada, con el fin de identificar problemas actuales que puedan llegar a ser solucionados mediante el diseño y aplicación de nuevas técnicas, asimismo como a través del desarrollo o la extensión de los componentes de arquitectura de red.Con este propósito, se han definido una serie de propuestas relacionadas con aspectos cruciales, así como el control de dispositivos ópticos por SDN para habilitar el manejo de redes híbridas, la necesidad de definir un mecanismo de descubrimiento de topologías ópticas capaz de exponer información precisa, y el analizar las brechas existentes para la definición de una arquitectura común en fin de soportar las comunicaciones 5G.Para validar estas propuestas, se han presentado una serie de validaciones experimentales por medio de escenarios de prueba específicos, demostrando los avances en control, orquestación, virtualización y manejo de recursos con el fin de optimizar su utilización. Los resultados expuestos, además de corroborar la correcta operación de los métodos y componentes propuestos, abre el camino hacia nuevas formas de adaptar los actuales despliegues de red respecto a los desafíos definidos en el inicio de una nueva era de las telecomunicaciones.Postprint (published version

Desarrollo de estrategias para reducir la producción de metano a nivel ruminal por el ganado bovino en México

Se ha demostrado que los taninos en el follaje de los árboles y arbustos pueden reducir la producción de metano (CH4) en el rumen de los bovinos. Se evaluó el potencial de diez especies de arbustivas, nativas del área templada de México, para reducir la producción de metano a nivel ruminal. Se utilizó la técnica de producción de gas in vitro para evaluar el efecto de la inclusión de estas plantas a tres niveles (10, 20 y 30%) en una dieta experimental. Dos experimentos independientes se hicieron para controlar la producción de gas metano a lo largo de 24 y 72 h de incubación, la producción de metano se registró después de 24 h. Los resultados mostraron una disminución significativa (P <0,05) en la producción de metano con la inclusión de todas las plantas, se observó la mayor disminución cuando Amaranthus spinosus, Commelina coelestis, Tagetes erecta y Senna hirsuta fueron incluidos en comparación con la dieta control. La digestibilidad de la fibra detergente neutra (FDN) después de la incubación no se vio afectada por Tagetes erecta, Amaranthus spinosus, Commelina coelestis mientras Senna hirsuta la aumentó (P <0.05). Los resultados sugieren que Amaranthus spinosus, Commelina coelestis, Tagetes erecta y Senna hirsuta tienen potencial para reducir las emisiones de metano del ganado bovino

BEYOND TRADITIONAL BOUNDARIES: REGIONAL AND GLOBAL DIMENSIONS OF NATIONAL WATER RESOURCE MANAGEMENT

This thesis introduces a framework that aims to support decision-making for enhanced water and food security, while adopting the understanding that water and food sectors are becoming increasingly unrestricted to specific borders or boundaries due to the globalization of resources and the interdependencies among the water, food, and other sectors. This framework is used, with some modifications, in three different applications that are presented in three respective peer-reviewed articles. The first article introduces a novel framework, called the national water, food, and trade (NWFT) modelling framework, that consists of two components: a national model that simulates the supply and demand of water and food on a national level, and a data-driven international virtual water (food) trade model that captures national virtual water exports and imports associated with trade in agricultural and animal products. Egypt is used as a case study for the application of the NWFT framework, with the national water and food gaps evaluated for a baseline period (1986–2013) and projected up to 2050 based on four national development scenarios. Results indicate the alarming situation of Egypt’s projected food gap by the year 2050, by which time food imports are projected to have to increase on average by 200% compared to 2021 values. The NWFT framework was able to successfully simulate the effect of water use and various socioeconomic variables, including population growth rate, on Egypt's historical food and water gaps. The framework could be easily adopted for other countries and regions. In the second article, the NWFT framework is modified to be an optimization-simulation framework and is presented as a multi-objective approach that aids policymakers in water-food security assessment and management while taking into account the major non-agricultural water uses associated with national development scenarios, the globalization of resources through the food trade, and the performance of the proposed solutions under possible national and global changes. The framework is formulated to minimize the agricultural water demand, food imports, and economic cost of imports as well as maximize the national gross margin of agriculture. Egypt is considered as the case study, with a set of alternative cropping patterns generated and evaluated for the baseline period (1986-2013) as well as under future conditions up to the year 2050. The results show the framework is useful for proposing cropping patterns that could have worked better for Egypt during the baseline period, but also cropping patterns that outperform the historical cropping pattern in each objective function for a wide range of future conditions. In the third article, the water-food assessment framework is expanded in its sectoral representation to include hydropower generation as the most relevant component of the energy sector. The framework is configured for a regional case study of the Eastern Nile Basin (ENB) countries of Egypt, Sudan, South Sudan, and Ethiopia, and set to simulate the ENB’s water resources, food production, and hydropower generation as a water-energy-food (WEF) nexus. The framework is calibrated and validated for the period from 1983 to 2016, then utilized to project a wide range of future development plans up to the year 2050. Four measures are used to evaluate the performance of the WEF nexus under each of these plans. A thematic pathway of development in the region that shows high potential for mutual benefits is identified and analyzed under several combinations of future social and climatic changes. Results show the ENB countries can reach significantly better food security conditions before 2050 and can generate an additional 42000 GWh/year of hydropower without significantly diminishing the downstream (Egypt) water scarcity problem. WEF performance measures of the ENB countries are significantly sensitive to climate change; however, under low population growth rates the climate change impacts on WEF security are less severe

Self-sorting of deformable particles in a microfluidic circuit

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 54-57).In this thesis, a new microfluidic device is presented for sorting of deformable particles based on the hydrodynamic resistance induced in a microchannel. Hydrodynamic resistance can be related to physical properties, including size and deformability of the particle, and can also be influenced by particle-wall interactions, hence allowing sorting based on any of these characteristics. This device could find application in cell sorting and bioseparation for therapeutics, research, and point-of-care diagnostics, as well as in sorting of droplets and emulsions for research and industrial applications (e.g., pharmaceutics, food industry, etc.). The device design is carried out using an equivalent resistance model, and numerical simulations are used to validate the design. The device is fabricated in PDMS, flow velocities are characterized using particle streak velocimetry, and sorting experiments are conducted to sort deformable gelatin particles according to size, and droplets of water and glycerol according to deformability. A sorting resolution of approximately 1 pm was obtained when sorting based on size, and droplets of water and glycerol were sorted into separate streams when sorting based on deformability. The main strength of the device over existing technology lies in its simplicity: sorting is carried out passively in the microfluidic circuit, eliminating the need for additional detection or sorting modules. Moreover, the device could be easily customized to change the sorting parameter or the sorting threshold, and multiple devices can be combined in parallel (to increase throughput) or in series (to increase resolution).by Mohamed Salem Raafat.S.M

WAVE PROPAGATION IN TENSEGRITY AND PERIODIC STRUCTURES

This dissertation focuses on the development of the fundamental understanding of the dynamic behavior of assemblies of periodic arrays of tensegrity unit cells (along one and two directions). The ultimate aim of the dissertation is to capitalize on the attractive attributes of tensegrity structures with the unique characteristics of periodic structures, which stem from their ability to impede the propagation of disturbances that fall within certain frequency bands (known as stop bands or bandgaps). A successful implementation of such periodic/tensegrity structures is envisioned to extend the usefulness of tensegrity to vibration isolation problems, as well as to the synthesis of tunable acoustic and elastic wave filters, in both the frequency and spatial domains. In this dissertation, numerical analysis of the statics and kinematics of icosahedron tensegrity cells are developed. The developed relationships are utilized to conceive one- and two-dimensional periodic arrays by appropriate stacking of icosahedron tensegrity cells. Alternative configurations for the periodic tensegrity arrays are considered for improved band gap characteristics, and a novel design for a periodic, tensegrity-based damper/vibration isolator is presented and demonstrated. Particular emphasis is placed here on investigating and demonstrating some of the very interesting elastic properties of the periodic/tensegrity structures. Among these properties is the ratio of the bulk modulus to the shear modulus which are shown to be on the order of 1000. These values are two orders of magnitude higher than any naturally-occurring bulk material, suggesting that the viable potential of the periodic/tensegrity structures as suitable candidates for the synthesis of practical and realizable “pentamode” metamaterials, with many potential applications in the novel areas of acoustic and elastic cloaking where the proposed periodic/tensegrity structures act as liquids to ensure proper impedance matching

Bewertung von Extraktionsmethoden für Uran in Böden

Uranium (U) occurs naturally in low concentrations in rock, soil, and water. The background concentration of U in soil ranges from 0.3 to 12.0 mg kg-1. The U behavior in soils is very complicated, this because U can be associated with numerous compounds and phases and many factors affect its behavior in soil. The main goals of the present work were to evaluate different extraction methods for U from soil, find out which of these methods will best predict the plant uptake of U and investigate some of the factors affecting the extractability of U and its availability for plants. Four soil sample groups were collected covering a wide range of U concentration in soils. Some of them were derived from previously conducted greenhouse, incubation and long term P fertilization experiments. The others were collected from the mining area of Schneeberg, Saxony. Acid ammonium acetate-EDTA (AAAc-EDTA), ammonium acetate (NH4Ac) at pH 7.0, diethylene triamine pentaacetic acid (DTPA), and soil solution obtained by centrifugation (7,000 rpm for 20 min) were used for U extraction. The U content in the solutions was measured by ICP-QMS. The results revealed that AAAc-EDTA, NH4Ac, DTPA and soil solution extractants had different capacities to extract U from soil. The AAAc-EDTA and NH4Ac were the best predictors for U uptake by maize, while DTPA and AAAc-EDTA extractants were the best indicators for the U uptake by sunflower. Maize had a lower ability to mobilize U into the soil after harvesting than sunflower and faba bean plants. The total U in soil found to be one of the most important factors affecting the extractability of U. Soil pH and P had inconsistent effects on the U extractability. Their impacts on the extractable U were depending on the samples source. The presence and the type of organic materials in soil had various effects on the availability of U. The effect of storage time was found to be one of the factors affecting the availability of U in soil.Als natürlicher Bestandteil liegt Uran (U) in Böden in geringer Konzentration (0,3 bis 12.0 mg kg-1 U) vor. In landwirtschaftliche Böden erfolgt ein zusätzlicher U-Eintrag durch P-Dünger. U-Extraktionsverfahren wurden aus herkömmlichen Schwermetall-extraktionsverfahren evaluiert und hinsichtlich ihres Extraktionspotentials verglichen. Die wichtigsten Parameter, die die Bioverfügbarkeit von U für Pflanzen in unterschiedlich U-kontaminierten Böden beeinflussen, werden diskutiert. Vier Gruppen von Bodenproben wurden untersucht, die den weiten Bereich praktisch möglicher U-Konzentrationen abdeckten. Sie entstammten vorherigen Gefäß- und Inkubationsversuchen, zwei P-Dauerdüngungsversuchen sowie einer Bergbauregion in Schneeberg (Sachsen, Deutschland). Für die Extraktion wurden AAAc-EDTA, DTPA, NH4Ac ( pH 7,0) sowie durch Zentrifugation gewonnene Bodenlösung eingesetzt. Der U-Gehalt in den Extraktionslösungen wurde mittels ICP-QMS gemessen und mit den Pflanzen-U-Gehalten des vorhergehenden Experiments korreliert. Die geprüften Extraktionsmittel unterschieden sich hinsichtlich ihres Extraktionspotentials, wobei mit AAAC-EDTA die größten U-Mengen extrahiert werden konnten, während in der Bodenlösung erwartungsgemäß am wenigsten pflanzenaufnehmbares U nachgewiesen wurde. Die Vorhersagegenauigkeit für die U-Aufnahme durch Pflanzen war vom verwendeten Extraktionsmittel und der Pflanzenart abhängig. Die U-Aufnahme durch Zea mays L. und Helianthus annuus L. korrelierte am besten mit dem AAAc-EDTA-extrahierbaren U. Die U-Aufnahme von Vicia faba L. konnte mit keinem der verwendeten Extraktionsmittel eingeschätzt werden. Der U-Gesamtgehalt, der pH-Wert und P-Verbindungen im Boden beeinflussten Extrahierbarkeit und Pflanzenaufnehmbarkeit des Schwermetalls U. Zusätzlich wurde der Einfluss von N- und S-Düngung auf die U-Aufnahme durch Pflanzen untersucht. Die Lagerungszeit der U-kontaminierten Bodenproben hatte ebenfalls einen Einfluss auf die Menge an extrahierbarem U

Neutrophil CD64 as a diagnostic marker of sepsis in children

Background: Sepsis is one of the leading causes of mortality among children worldwide. Reliable evidence was insufficient in pediatric sepsis and many aspects in clinical practice actually depend on expert consensus with some evidence in adult sepsis.Objective: This study aimed to investigate neutrophil expression of CD64 in septic children and in healthy controls. We hypothesized that these receptors are elevated during sepsis and can be used as a diagnostic marker.Methods: This study was carried out on 50children with pediatric sepsis and 40 apparently healthy children as controls. Cases were recruited from the PICU of Al Zahraa University Hospital, Al-Azhar University for Girls in the period from May 2014 to March 2015. All the cases were assessed clinically and by routine laboratory investigations. Expression of neutrophil CD64 was measured by flow cytometry.Results: The mean CD64 expression in children with sepsis (66.49 ± 23.45) was significantly higher than in the control group (9.39 ± 6.17) p&lt;0.001 .CD64 expression had a significant positive correlation with CRP level (r=0.416, p&lt;0.003). ROC curve for CD64 expression showed100% sensitivity and specificity. The most common isolated organisms were gram negative organisms mainly E. coli. A highly significant increase was demonstrated in CRP and TLC values in the culture proven sepsis group compared to clinical sepsis group, while there was nostatistical significant difference in CD64 values between the two groups.Conclusion: change in cell surface expression of CD64 on peripheral blood neutrophils can be considered a sensitive marker for the detection of pediatric sepsis.Keywords: Neutrophil, CD64, sepsis, childre