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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Glutathione transferase isoenzymes in rat hepatocarcinogenesis

Dalton, K. G. January 1987 (has links)
No description available.
2

Multifunctional Materials for Catalysis: Dendron Encapsulated Nanoparticles Supported on Silica

January 2019 (has links)
archives@tulane.edu / Porous materials possess voids of varying size of and uniformity and are of great significance in many areas such as adsorption, separations, sensors, gas storage, and catalysts. Organic-inorganic hybrid materials, as one type of porous materials, combines hard and soft matter synergistically, and have attracted considerable attention. As the scientific community pushes the boundaries of hybrid materials, more complicated architecture have been developed to achieve the desired functionality. Multifunctional materials with elaborate designs of architecture, especially actives sites for certain applications are needed. Dendrimer-encapsulated nanoparticles (DENs) have attracted interest since they were first introduced. This synthetic approach leads to well-defined sizes, compositions and structures of nanoparticles controlled by the dendrimer template. Melamine-based dendrimers were successfully grafted to OMS supports through an aminosilane handle. More recently the supported dendrimers were used as templates to form Palladium nanoparticles, resulting in encapsulated palladium/dendron-OMS materials. Multiple characterizations were used to validate both the structural integrity of the dendrimers and the nature of the metal nanoparticles formed. Probe reactions have shown the accessibility of both metal sites and amine sites from dendron. In this work, we used the organic architecture tethered to the support to not only make the metal nanoparticles while attached to the solid surface, but also utilize the metal and ligand functionalities of the resulting material. Multiple active sites indicate the dendron encapsulated palladium nanoparticles can be further used as multifunctional catalysts. Support topology and dendron structure of the encapsulated palladium/dendron-OMS play important roles in the catalysis and capture performance. We studied how the pore structures influence the loading of dendron, further influence carbon dioxide capture properties. We also studied how the different types of amines in the dendron unit participate in binding multiple types of small molecules by designing similar dendrons with different peripheral nitrogen. Carbon dioxide uptake is controlled by the peripheral amines with little interior contribution. However, interior nitrogen atoms participate in metal binding and catalysis, though involved with different kinds of nitrogen types. Sustainably meeting the growing energy needs of the planet is one of the 21st century’s grand challenges. Many pathways to meeting our energy needs while reducing fossil-fuel consumption have been posited, all with challenges. One possible route is to convert biomass into fuels. We utilized encapsulated palladium/dendron-OMS as multifunctional catalyst, they are used for multistep reaction. We designed a three-step process that includes hydrogenation of phenol, aldol condensation, and hydrogenation of aldol reaction product to produce fuels from oxygenates using palladium containing dendrons supported on OMS. The operating conditions of low temperature and low pressure hydrogen in aqueous media is consistent with green chemistry goals. / 1 / Yueyun Lou
3

The molecular genetics of polyketide biosynthesis in filamentous fungi

Bingle, Lewis Edward Hector January 1997 (has links)
No description available.
4

Transpace : an architectural intervention for people in transition

Meiring, Christina Isabella 25 July 2008 (has links)
Identity, belonging and being are some of the aspects inventively explored in this document. In times of fundamental change, people tend to find a space, lose it and then find another space as life and the world transform around them. What does this metamorphosis entail and in what ways are we affected by it? How do we live through it and what may we become on our journey towards each other, particularly when the space and places from which we depart are – at least on the surface – so vastly different? Within our voyages of transitional discovery, we too often repudiate the underlying structure from which our values, norms and standards are born – the configuration of beliefs that, when being threatened, results in conflict, bringing forth anger and dispute. The proposed discourse initiates another way of being by concretizing phenomenological philosopher Martin Heidegger’s notion of dwelling. It furthermore explores the contributions made by American architect Christopher Alexander, indicating important ways in which Heidegger’s dwelling can be translated into more grounded architectural meaning. Within the urban context, the design addresses these fundamental structures of being and the predicaments experienced between people and place. / Dissertation (MArch(Prof))--University of Pretoria, 2008. / Architecture / unrestricted
5

Development and Analysis of a Multifunctional Fuel Cell Structure

Hilton, Corydon 05 November 2009 (has links)
Multifunctional material systems are systems that contain individual materials or components which are capable of performing multiple functions. The combination of functions into single entities allows for system-level benefits that are not possible through the optimization of subsystems independently. Benefits enabled through multifunctional designs include increased system efficiency through mass and or volume savings as well as part count reductions. Fiber reinforced polymer (FRP) composite materials are lightweight, high-strength materials that can be tailored to achieve a unique set of properties. These characteristics make composites ideal materials for multifunctional designs. The current research focuses on the production, optimization, and characterization of a multifunctional fuel cell system. This product combines fuel cell technology with composite materials technology to achieve a design that produces electrical power while also providing specific load carrying capability. The study investigates new system designs and new processing techniques, including vacuum assisted resin transfer molding (VARTM) and pultrusion. A metric which allows for the characterization of multifunctional fuel cell systems is developed and applied to three fuel cell designs. This metric uses Frostig's Higher Order Theory to analyze the mechanical behavior of the cells while the electrical performance of each device is based on its specific power output. For the cells investigated here, multifunctional efficiencies between 22% and 69% are achieved. The multifunctional efficiency is highly dependent on the transverse pressure applied to the fuel cell components, as this pressure determines ohmic resistances, mass transfer properties, and sealing abilities of the systems. The mechanical pressures at the GDL/Polar Plate interface of a model fuel cell system are explored via experiments with pressure-sensitive film as well as FEA studies, and an optimum structural pressure of approximately 200 psi is identified. Additionally, the effects that concentrated, bending loads have on the electrochemical performance of a model multifunctional cell are explored. The results indicate that one must give generous consideration to the out of plane loads which the fuel cell system will be subjected to (both inherent, structural loads resulting from processing conditions and external, applied loads encountered during operation) in order to achieve optimal multifunctional efficiency. / Ph. D.
6

O projeto de arquitetura do Espaço Brooklin - da concepção à implantação: o arquiteto e o projeto de um empreendimento imobiliário de grande porte / The architecture design of the Brooklyn Mixed-use Complex - from design to deployment and building: the architect and design of a large real estate development

Rossi, Oriode José 09 October 2007 (has links)
Este trabalho mostra o percurso e a evolução do projeto de arquitetura de um conjunto multifuncional edificado de grande porte. E, nesse contexto, estuda as principais variáveis que influenciam diretamente as decisões sobre a natureza dos espaços e sobre as definições quanto a sua construção. Nosso objetivo é mostrar como são definidos os caminhos do projeto, as fases do seu desenvolvimento e salientar os pontos críticos relativos à sua qualidade. E, para atingirmos esse objetivo vamos discutir a evolução dos estudos preliminares, o anteprojeto e as inúmeras alterações no programa do Espaço Brooklin nosso estudo de caso - mostrando a evolução do lugar, aspectos econômicos imobiliários que influenciaram o projeto, o processo que constituiu a formação do grupo empreendedor, e como esse conjunto de forças refletiu decisivamente no desempenho do trabalho dos arquitetos e consequentemente na definição do projeto. / This work focuses the course and the design of a multi-use building and it studies the main variables that strongly affects the decisions about the character of the space and the definition of the building. This studys objective is to show how the roads to the project are defined, their development fazes, and how the design details critical points to the overall quality of the finished project. To be able to accomplish this objective I am going to discuss the evolution of the preliminary studies, the layout, and the many changes on the Brooklin Space program my study case sharing the spaces evolution, the financial aspects of such project, the process to form a group of investors and how all of the above aspects reflected decisively in the architectural work and, consequently, in the projects definition.
7

Geografiska perspektiv på en multifunktionell arena i Stockholmregionen

Rückertz, Robert, Persson, Magnus January 2006 (has links)
<p>The capital of Sweden, Stockholm has in the recent years begun to discuss the option to build a new major arena for sports and events. The vision is a multifunctional arena with a capacity of 55.000 to 60.000 seats. In Sweden today only Gothenburg has got an arena (Ullevi) with that ability. Ullevi is today the centre for sport events and musical events. The prospect for Stockholm is to get a similar opportunity as Gothenburg with the visualised arena. The fact is that Stockholm today loose events in favour towards Gothenburg.</p><p>This geographical study takes its aim to comprehend how an arena makes spatial effects in local, regional and national levels in economic geographical perspectives.</p><p>In a deeper perspective, what kind of effects can the visionary arena in terms of concurrence with other arenas in the vicinities and how the arena effects its locality, its region and the nation.</p><p>The theories that have been implemented in the study are the Central place theory, the localisation and regional development theories and Porters Diamond. In the study recent and older science of sports geography, science of events and city regeneration is treated. There is also a comprehensive background investigation of the city of Gothenburg and Stockholm and their development from industrial cities towards becoming more event based cities.</p><p>The study is mainly based on three interviews. The interviews are made with Stockholm town, The Swedish Football Association and Solna town. It is among these actors that the visionary arena plans has its strongest expressions. Thru the interviews the study show a couple of different themes and results. For example there are competitor like factors in their visions. They are looking to compete both against the western side of Europe thru the Ullevi arena, and with the eastern side of Europe, mainly the Baltic Sea area, with the new arena in Stockholm. An other factor is the vision to strengthen the status of Stockholm as a leading city of events.</p>
8

A Multifunctional MEMS Pressure and Temperature Sensor for Harsh Environment Applications

Najafi Sohi, Ali January 2013 (has links)
The objective of this thesis was to develop a fast-response multifunctional MEMS (Micro Electro Mechanical Systems) sensor for the simultaneous measurement of in-cylinder pressure and temperature in an internal combustion (IC) engine. In a representative IC engine, the pressure and temperature can reach up to about 1.6 MPa and 580 °C, respectively, at the time of injection during the compression stroke. At the peak of the combustion process, the pressure and temperature near the cylinder wall can go beyond 6 MPa and 1000 °C, respectively. Failure of current membrane-based MEMS pressure sensors operating at high temperatures is mainly caused by cross-sensitivity to temperature, which affects the pressure readout. In addition, the slow thermal response of temperature sensors used for such a dynamic application makes real-time sensing within a combustion engine very challenging. While numerous approaches have been taken to address these issues, no MEMS sensor has yet been reported that can carry out real-time measurements of in-cylinder pressure and temperature. The operation of the sensor proposed in this Thesis is based on a new non-planar and flexible multifunctional membrane, which responds to both pressure and temperature variations at the same time. The new design draws from standard membrane-based pressure and thermostatic-based temperature MEMS sensing principles to output two capacitance values. A numerical processing scheme uses these values to create a characteristic sensing plot which then serves to decouple the effects of pressure and temperature variations. This sensing scheme eliminates the effect of cross-sensitivity at high temperatures, while providing a short thermal response time. Thermal, mechanical and electrical aspects of the sensor performance were modeled. First, a semi-analytical thermo-mechanical model, based on classic beam theory, was tailored to the shape of the multifunctional membrane to determine the sensor’s response to pressure and temperature loading. ANSYS® software was used to verify this semi-analytical model against finite element simulations. Then the model was then used to calculate the capacitive outputs of the multifunctional MEMS sensor subjected to in-cylinder pressure and temperature loading during a complete cycle of operation of a typical IC engine as well as to optimize the sensor specifications. Several prototypes of the new sensing mechanism fabricated using the PolyMUMPs® foundry process were tested to verify its thermal behavior up to 125 °C. The experiments were performed using a ceramic heater mounted on a probe station with the device connected to a precision LCR-meter for capacitive readouts. Experimental results show good agreement of the temperature response of the sensor with the ANSYS® finite element simulations. Further simulations of the pressure and temperature response of different configurations of the multifunctional MEMS sensor were carried out. The simulations were performed on an array of 4200 multifunctional devices, each featuring a 0.5 µm thick silicon carbide membrane with an area of 25×25 µm2, connected in parallel shows that the optimized sensor system can provide an average sensitivity to pressure of up to 1.55 fF/KPa (over a pressure range of 0.1-6 MPa) and an average sensitivity to temperature of about 4.62 fF/°C (over a temperature range of 160-1000 °C) with a chip area of approximately 4.5 mm2. Assuming that the accompanying electronics can meaningfully measure a minimum capacitance change of 1 fF, this optimized sensor configuration has the potential to sense a minimum pressure change of less than 1 KPa and a minimum temperature change of less than 0.35 °C over the entire working range of the representative IC engine indicated above. In summary, the new developed multifunctional MEMS sensor is capable of measuring temperature and pressure simultaneously. The unique design of the membrane of the sensor minimizes the effect of cross-sensitivity to temperature of current MEMS pressure sensors and promises a short thermal response time. When materials such as silicon carbide are used for its fabrication, the new sensor may be used for real-time measurement of in-cylinder pressure and temperature in IC engines. Furthermore, a systematic optimization process is utilized to arrive at an optimum sensor design based on both geometry and properties of the sensor fabrication materials. This optimization process can also be used to accommodate other sensor configurations depending on the pressure and temperature ranges being targeted.
9

Design concept for a Multifunctional Hygiene Cabin 2014

Casadesus Baldursson, Jordi Hans January 2013 (has links)
The project  is related to the design of a new type of Public Toilets from the company Danfo for the year 2014.   The proper project follows asequential order to show how to create solution to the existing problems of these Service  and re-design the product itself to create a new look and new core values to the existing service , creating   a new product line for this kind of service in the market in this particular case the re-design  of a new type of Public Toilets for the year 2014.   Following the sequential order of a  design process it is proposed a new concept of Public Toilets  which will give service to users in City’s and Landscape areas. Developing a new  style and realistic concept of Publict Toilets.  Creating  sustainable buildings  which generate the 60 % of the own used energy,  using renewable energy sources from sun and wind, reusing the rainwater and with purifying water systems, for minimum water consumption, moreover a building  design to avoid vandalism and which give different services on the exterior creating information  reunion point, for the interior is looked at  the essence of  Public Toilets and why they where designed,  creating a new concept of  a multifunctional Hygiene cabin, and resolving the existing detected problems to create a  design concept that satisfied all the stakeholders involved in  the proper artifact and combined with the innovation of the design to open new markets.   A new type of Public Toilets with  new core values and which gives new services based on the conclusion and reflections of the  done research. It is proposed a Re-design of the Exterior and Interior  of the existing building and the design  of two  new artifacts  for the interior which resolves and gives service, creating new goals for the company  and a new style. Combined with the existing technology and production methods  and materials thinking in the future development and trends.
10

Biomedical Nanocrystal Agents: Design, Synthesis, and Applications

Cho, Minjung 16 September 2013 (has links)
In these days, nanomaterials are applied in a variety of biomedical applications including magnetic resonance imaging (MRI), cell imaging, drug delivery, and cell separation. Most MRI contrast agents affect the longitudinal relaxation time (T1) and transverse relaxation time (T2) of water protons in the tissue and result in increased positive or negative contrast. Here, we report the optimization of r1 (1/T1) or r2 (1/T2) relaxivity dynamics with diameter controlled gadolinium oxide nanocrystals (2~22 nm) and iron based magnetic nanocrystals (4 ~33 nm). The r1 and r2 MR relaxivity values of hydrated nanocrystals were optimized and examined depending on their core diameter, surface coating, and compositions; the high r1 value of gadolinium oxide was 40-60 S-1mM-1, which is 10-15 fold higher than that of commercial Gd (III) chelates (4.3~4.6 S-1mM-1). Moreover, in vitro toxicological studies revealed that polymer coated nanocrystals suspensions had no significant effect on human dermal fibroblast (HDF) cells even at high concentration. Towards multimodal imaging or multifunctional ability, we developed the iron oxide/QDs complexes, which consist of cores of iron oxide that act as nucleation sites for fluorescent QDs. The choice of variable QDs helped to visualize and remove large iron oxide materials in a magnetic separation. Additionally, diluted materials concentrated on the magnet could be fluorescently detected even at very low concentration. The designed MRI or multifunctional nanomaterials will give great and powerful uses in biomedical applications.

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