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Methods for the syntheses of compositionally diverse dendrimersSteffensen, Mackay Bagley 01 November 2005 (has links)
Dendrimers are a unique class of macromolecules that present perfect branching on a molecular scale. The pattern of branching at the atomic scale is compared to the branching of trees, from whence dendrimers get their name. Dendrimers have been attractive synthetic targets for the past twenty years. The methods and building blocks used in the synthesis of dendrimers vary, but molecules of this class of polymeric materials all possess symmetrical branching emanating from the core. At each branch point the number of groups increases exponentially. Efforts directed toward the synthesis of dendrimers presenting multiple functional groups at the surface and within the dendrimer structure are described.
Methods are described which provide access to dendrimers in a one-pot per generation fashion, with triazines as the common moiety. Chemoselective routes utilize the temperature dependant substitution of cyanuric chloride to construct dendrimers, obviating the use of protected monomers or the need to manipulate functional groups during the synthesis. These methods are atom economical, as the only by-products are HCl and a base to scavenge it. The methods are efficient, with typical isolated yields of product in the middle to high ninety percent range, often on a multi-gram scale. Methods are described for conducting three separate reactions in a single pot. Specific emphasis is placed on structural control of the interior and surface groups of the dendrimers.
The synthesis of a G3 dendrimer of layered composition is described. The use of a different difunctional linkage group for each generation of dendrimer growth produced a G3 dendrimer with layered composition without the use of protecting groups or functional group interconversions.
A G3 dendrimer was synthesized presenting five different functionalities at the periphery on a 10 gram scale, resulting in approximately 70% overall yield. The peripheral groups are composed of orthogonal functionality, which can be independently and selectively unmasked or manipulated in the presence of the other functionality.
The syntheses of dendrimers incorporating the short linker hydrazine produce materials with interesting physical properties as well as a low ratio of carbon to nitrogen. The use of dendrimers in the construction of novel macromolecular constructs is also described.
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Geografiska perspektiv på en multifunktionell arena i StockholmregionenRückertz, Robert, Persson, Magnus January 2006 (has links)
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. This geographical study takes its aim to comprehend how an arena makes spatial effects in local, regional and national levels in economic geographical perspectives. 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. 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. 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.
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Ekosystemstödjande och multifunktionella växtval i urban miljö : En fallstudie med utgångspunkt i Nacka stadsbildningÅshage, Anna January 2014 (has links)
This study has investigated how urban vegetation can be used in a multifunctional way to support ecosystem services in urban environments. Nacka municipality is in the start-up phase of building what is to become Nacka city. This provides a unique possibility to study and analyse what role the vegetation play in making the city a healthy living environment and how it needs to be adapted in order to be resilient against changing climate conditions and how the effects of those changes can be regulated. The study further investigates how airborne pollution, caused by urbanization processes, can be regulated or reduced by vegetation or species selection. Methods used in this study were a combination of qualitative interviews and literature studies, seeking to answer the questions: Which specific ecosystem functions are needed in the urban environment and which aspects will influence the ecosystems ability to deliver the functions in demand? And which plant species have the right mechanisms needed to deliver those functions? These questions have been studied and analysed in a local based context where the local conditions ands site specific needs of Nacka define criteria for plant selection. Based on those criteria, a plant list is presented that seeks to find synergies and effectiveness in plant selection with the aim to find plants that support and/or produce multiple ecosystem functions.
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A Multifunctional MEMS Pressure and Temperature Sensor for Harsh Environment ApplicationsNajafi 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.
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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 developmentOriode José Rossi 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.
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The Design, Synthesis, and Biological Evaluation of Novel Peptidic Ligands for the Treatment of Chronic Neuropathic PainRemesic, Michael Vincent, Remesic, Michael Vincent January 2017 (has links)
Chronic neuropathic pain is a disease that impacts the livelihood of millions of people in the United States with no effective pain treatments and limited information pertaining to the underlying mechanisms. Opioid therapy is considered the gold standard for pain therapeutics, but chronic use of these medications brings about serious side effects such as tolerance, addiction, and respiratory depression which limit their overall therapeutic potential. Herein, two approaches are discussed to circumvent these issues: i) a multifunctional approach using N-phenyl-N-piperidin-4-yl-propionamide (Ppp) coupled to various endogenous opioid ligand scaffolds, and ii) non-opioid dynorphin A (DYN A) ligands at the Bradykinin-2 receptor (B2R).
The μ-opioid receptor (MOR) upon agonist stimulation provides analgesia and concomitant activation of the δ-opioid receptor (DOR) leads to an increased antinociceptive effect. Chronic activation of the MOR has been correlated with an upregulation of the κ-opioid receptor (KOR) and KOR associated side effects such as anxiety and depression. The discovery of a new class of opioid receptor (OR) ligands that have the biological profile of MOR/DOR agonists and KOR antagonists would be beneficial considering they would have an increased analgesic effect, leading to a lower dosage being administered and thus lower overall side effects, and block symptoms elicited from KOR stimulation. Discussed are various structure activity relationships (SARs) of numerous scaffolds that present novel biological profiles. Ultimately, we discovered a compound that, to our knowledge, is the 1st MOR/DOR agonist and KOR antagonist.
DYN A is the endogenous ligand for the KOR and its [des-Tyr1]-DYN A fragment interacts with the B2R, but not the KOR, promoting hyperalgesia. Peptidomimetic non-opioid DYN A analogues were synthesized and evaluated at the B2R. A minimum pharmacophore was identified and antagonists with both improved biological stability and affinity were discovered.
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Multifunctional Flexible Laser-Scribed Graphene Sensors for Resilient and Sustainable ElectronicsKaidarova, Altynay 04 1900 (has links)
The Fourth Industrial Revolution is driven by cyber-physical systems, in which sensors link the real and virtual worlds. A global explosion of physical sensors seamlessly connected to networks is expected to produce trillions of sensors annually. To accommodate sustainable sensor production, it is crucial to minimize the consumption of raw materials, the complexity of fabrication, and waste discharge while improving sensor performance and wearability. Graphene has emerged as an excellent candidate material for its electrical and mechanical characteristics; however, its economic impact has been hindered by complex and energy-intensive processes. Meanwhile, printed electronics offer a compelling range of merits for scalable, high-yield, low-cost manufacturing of graphene. Among them, the one-step laser scribing process has enabled a simultaneous formation and patterning of porous graphene in a solid-state and opened new perspectives for versatile and widely tunable physical sensing platforms.
This dissertation introduces flexible, lightweight, and robust Laser-Scribed Graphene sensor solutions for detecting various physical parameters, such as strain, flow, deflection, force, pressure, temperature, conductivity, and magnetic field. Multifunctionality was obtained by exploiting the direct laser scribing process combined with the flexible nature of polyimide and the piezoresistivity of porous graphene. The outstanding properties of LSG, such as low cytotoxicity, biocompatibility, corrosion resistance, and ability to function under extreme pressure and temperature conditions, allowed targeting diverse emerging applications.
As a wearable device in healthcare, the LSG sensor was utilized to monitor motions involving joint bandings, such as finger folding, knee-related movements, microsleep detection, heart rate monitoring, and plantar pressure measurements. The marine ecosystem was used as an illustrative sensor application to cope with harsh environments. To this end, the sensor measured the velocity of underwater currents, pressure, salinity, and temperature while monitoring the movement of marine animals. The sensitivity to the magnetic field remained stable up to 400 °C, making the LSG sensor a viable option for high-temperature applications. In robotics, the LSG sensor was developed for velocity profile monitoring of drones and as a soft tactile sensor. The study provides insights into methods of improving sensor performance, opportunities, and challenges facing a tangible realization of LSG physical sensors.
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Multifunctional Multimaterial Fibers for Sensing and Modulation in Wearable and Biomedical ApplicationsZhang, Yujing 03 August 2023 (has links)
The aim of this dissertation is to summarize my research on the development of multifunctional multimaterial fibers that are designed and produced for sensing and modulation applications in wearable and biomedical fields.
Fiber-shaped devices have gained significant attention due to their potential in human-machine interface applications. These devices can be woven into fabrics to create smart textiles or used as implantable probes for various biomedical purposes. To meet the requirements of human-machine interface, these fiber devices need to be flexible, robust, scalable, and capable of integrating complex structures and multiple functionalities.
The thermal drawing technique has emerged as a promising method for fabricating such fiber devices. It allows for the integration of multiple materials and intricate microstructures, thereby expanding the functionality and applications of the devices. However, the range of materials and structures that can be integrated into these fiber devices is still limited, posing a constraint on their potential applications.
To address this limitation, the dissertation focuses on expanding the range of materials and structures that can be integrated into multimaterial fiber devices. This involves the development and application of stretchable electrical and optical deformation fiber sensors by incorporating composite thermoplastic elastomers through the thermal drawing process (Chapter 2). Additionally, the dissertation explores the use of the thermal drawing technique to create multifunctional ferromagnetic fiber robots capable of navigation, sensing, and modulation in minimally invasive surgery (Chapter 3). Furthermore, the integration of nano-optoelectrodes and micro robotic chips on the fiber tip using the combination of thermal drawing and lab-on-fiber techniques is investigated (Chapter 4). The dissertation concludes with an overview of the research findings and potential future directions in the field of multifunctional multimaterial fiber devices (Chapter 5). / Doctor of Philosophy / Human-machine interface (HMI) is the technology that enables communication and interaction between humans and machines or computer systems. It plays a vital role in various domains, including consumer electronics, robotics, healthcare, virtual reality, and industrial automation. Fiber-shaped devices have recently emerged as a promising technology for HMI applications due to their flexibility, lightweight nature, and versatile functionality. These devices can be seamlessly integrated into wearable forms, such as clothing or accessories, and even implanted in the body, opening up a wide range of possibilities for HMI.
In the past decades, significant progress has been made in developing multifunctional multimaterial fiber devices using the thermal drawing process (TDP). TDP allows for the fabrication of fibers with complex geometries and microstructures by heating and drawing a preform consisting of different materials. However, the current range of materials and structures that can be integrated into these fiber devices is still limited, which hinders their potential applications.
This dissertation aims to expand the capabilities of multimaterial fiber devices by exploring new materials and structures that can be incorporated using TDP. The research focuses on three main areas. First, the development and application of stretchable electrical and optical deformation fiber sensors by integrating composite thermoplastic elastomers are explored (Chapter 2). This enables the sensing of various deformations, enhancing the functionality of the fiber devices. Second, the dissertation investigates the creation of multifunctional ferromagnetic fiber robots capable of navigation, sensing, and modulation in minimally invasive surgery (Chapter 3). These robots offer new possibilities for precise and controlled interventions. Lastly, the integration of nano-optoelectrodes and micro robotic chips on the fiber tip using a combination of thermal drawing and lab-on-fiber techniques is explored (Chapter 4). This allows for advanced optical sensing and remote-control capabilities at the fiber tip.
Overall, these three aspects of the project broaden the capabilities and functionalities of multifunctional multimaterial fibers, making them highly versatile and suitable for a wide range of applications in wearable technology and biomedicine. These advancements have the potential to revolutionize the field of human-machine interface (HMI) by enabling seamless and intuitive communication, control, and feedback between humans and machines.
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Design and Frequency Characterization of Dual-Piezoresponsive Foam SensorsNewton, Cory Nelson 09 December 2016 (has links)
Multifunctional "self-sensing" materials at the frontiers of current research are generally designed to gather only a single type of information (such as quasi-static strain data). This project introduces a new sensor that is both multifunctional and dual-response, indicating its ability to not only perform in mechanical and sensing functions but also in its ability to sense multiple types of response. The proposed new class of sensing materials, comprised of nanocomposite polymer foams, exhibits measurable piezoresistive and quasi-piezoelectric phenomena in the form of change in resistance and voltage generation in response to deformation, respectively. An initial sampling of the envelope of dual-response nanocomposite foam sensors is mapped. The sensing materials can also be tailored to provide desired mechanical compliance and damping. Nanocomposite foam sensors decrease in resistance with increased strain in both static and cyclic compression environments. The quasi-piezoelectric voltage response of nanocomposite foam sensors increases linearly with compression frequency. A circuit and signal demodulation system was developed enabling simultaneous capture of a dual-response foam sensor's change in resistance and voltage generation. Measuring the two responses provides both long-term and immediate performance and health status of mechanical systems, enabling improved monitoring and decreased risk of failure.
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Multifunctional polymeric foams: preparation, characterization, and environmental aspectsGalvagnini, Francesco 25 October 2023 (has links)
Syntactic foams (SFs) are characterized by a unique combination of low density, high mechanical properties, and low thermal conductivity. Moreover, these properties can be tuned to specific applications. In contrast to traditional foams, where porosity is formed during the foaming process, porosity in syntactic foams can be obtained simply by incorporating pre-formed bubbles. Because of their high chemical stability and buoyancy, these type of foams found their first application in the marine industry. Nowadays, they are utilized in many other fields, such as in the aerospace and automotive industry. In this work, the multifunctionality of epoxy-based and polypropylene (PP)-based SFs was increased by including a microencapsulated Phase Change Material (PCM), able to impart Thermal Energy Storage (TES) capability at phase transition temperatures of 43 °C and 57 °C. The rheological, morphological, thermal, and mechanical properties of the prepared materials were systematically investigated. A final comparison of the two systems was performed to obtain a better comprehension of their potential in emerging industrial applications.
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