Dissertations / Theses on the topic 'Kinetic Design'
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1
Wenning, Matthew R. "Kinematic and kinetic differences in the barbell squat wearing two different types of shoes." Virtual Press, 2005. http://liblink.bsu.edu/uhtbin/catkey/1328122.
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The purpose of this study was to examine the differences in the squat kinematics and kinetics while wearing two different types of footwear. Ten men that compete at a collegiate level of powerlifting participated in the study. The participants performed the squat in both Chuck Taylor (flat soled) and Adidas (raised heel) shoes 3 times per shoe at 80% of 1 RM. During the testing sessions, sagittal plane kinematics of the shank were measured using 2-D video analysis. A force plate was used to measure the ground reaction forces of the right foot. There was no significant difference (p>0.05) in the medial lateral ground reaction forces (raised heel 63.58 N, flat soled 65.79 N), or the shank angles (raised heel 67.4 degrees, flat soled 65.7 degrees) of the participants. In conclusion, the participants were able to accommodate for a 1 inch raised heel in their shoe without altering shank position of medial-lateral ground reaction forces.School of Physical Education, Sport, and Exercise Science
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Po-Yi, Wu. "Affective and kinetic design in Brahms' duo sonatas." Thesis, King's College London (University of London), 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431173.
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Huan, Xun. "Accelerated Bayesian experimental design for chemical kinetic models." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59678.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 129-136).
The optimal selection of experimental conditions is essential in maximizing the value of data for inference and prediction, particularly in situations where experiments are time-consuming and expensive to conduct. A general Bayesian framework for optimal experimental design with nonlinear simulation-based models is proposed. The formulation accounts for uncertainty in model parameters, observables, and experimental conditions. Straightforward Monte Carlo evaluation of the objective function - which reflects expected information gain (Kullback-Leibler divergence) from prior to posterior - is intractable when the likelihood is computationally intensive. Instead, polynomial chaos expansions are introduced to capture the dependence of observables on model parameters and on design conditions. Under suitable regularity conditions, these expansions converge exponentially fast. Since both the parameter space and the design space can be high-dimensional, dimension-adaptive sparse quadrature is used to construct the polynomial expansions. Stochastic optimization methods will be used in the future to maximize the expected utility. While this approach is broadly applicable, it is demonstrated on a chemical kinetic system with strong nonlinearities. In particular, the Arrhenius rate parameters in a combustion reaction mechanism are estimated from observations of autoignition. Results show multiple order-of-magnitude speedups in both experimental design and parameter inference.
by Xun Huan.
S.M.
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Parkes, Amanda Jane. "Topobo : a gestural design tool with kinetic memory." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28768.
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Includes bibliographical references (leaves 89-91).Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2004.
The modeling of kinetic systems, both in physical materials and virtual simulations, provides a methodology to better understand and explore the forces and dynamics of our physical environment. The need to experiment, prototype and model with programmable kinetic forms is becoming increasingly important as digital technology becomes more readily embedded in physical structures and provides real-time variable data the capacity to transform the structures themselves. This thesis introduces Topobo, a gestural design tool embedded with kinetic memory--the ability to record, playback, and transform physical motion in three dimensional space. As a set of kinetic building blocks, Topobo records and repeats the body's gesture while the system's peer-to-peer networking scheme provides the capability to pass and transform q gesture. This creates a means to represent and understand algorithmic simulations in a physical material, providing a physical demonstration of how a simple set of rules can lead to complex form and behavior. Topobo takes advantage of the editability of computer data combined with the physical immediacy of a tangible model to provide a means for expression and investigation of kinetic patterns and processes not possible with existing materials.
Amanda J. Parkes.
S.M.
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Abraham, Thomas Kannankara. "Kinetic bounds on attainability in the reactor synthesis problem." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1126791863.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xvi, 190 p.; also includes graphics (some col.). Includes bibliographical references (p. 182-190). Available online via OhioLINK's ETD Center
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Zhou, Mingxia. "First-principles based micro-kinetic modeling for catalysts design." Diss., Kansas State University, 2018. http://hdl.handle.net/2097/38608.
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Doctor of PhilosophyDepartment of Chemical Engineering
Bin Liu
Efficient and selective catalysis lies at the heart of many chemical reactions, enabling the synthesis of chemicals and fuels with enormous societal and technological impact. A fundamental understanding of intrinsic catalyst properties for effective manipulation of the reactivity and selectivity of industrial catalysts is essential to select proper catalysts to catalyze the reactions we want and hinder the reactions we do not want. The progress in density functional theory (DFT) makes it possible to describe interfacial catalytic reactions and predict catalytic activities from one catalyst to another. In this study, water-gas shift reaction (WGSR) was used as a model reaction. First-principles based micro-kinetic modeling has been performed to deeply understand interactions between competing reaction mechanisms, and the relationship with various factors such as catalyst materials, structures, promoters, and interactions between intermediates (e.g., CO self-interaction) that govern the observed catalytic behaviors. Overall, in this thesis, all relevant reaction mechanisms in the model reaction on well-defined active sites were developed with first-principles calculations. With the established mechanism, the promotional effect of K adatom on Ni(111) on WGSR compared to the competing methanation was understood. Moreover, the WGSR kinetic trend, with the hydrogen production rate decreasing with increasing Ni particle diameters (due to the decreasing fractions of low-coordinated surface Ni site), was reproduced conveniently from micro-kinetic modeling techniques. Empirical correlations such as Brønsted-Evans-Polanyi (BEP) relationship for O-H, and C-O bond formation or cleavage on Ni(111), Ni(100), and Ni(211) were incorporated to accelerate computational analysis and generate trends on other transition metals (e.g., Cu, Au, Pt). To improve the numerical quality of micro-kinetic modeling, later interactions of main surface reaction intermediates were proven to be critical and incorporated successfully into the kinetic models. Finally, evidence of support playing a role in the enhancement of catalyst activity and the impact on future modeling will be discussed. DFT will be a powerful tool for understanding and even predicting catalyst performance and is shaping our approach to catalysis research. Such molecular-level information obtained from computational methods will undoubtedly guide the design of new catalyst materials with high precision.
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Gooch, S. D. "Design and mathematical modelling of the kinetic sculpture Blade." Thesis, University of Canterbury. Mechanical Engineering, 2001. http://hdl.handle.net/10092/7844.
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Christchurch born artist Len Lye (1901- 1980) built the kinetic sculpture, Blade
(1965), as a prototype for what he perceived to be a much larger work.
This thesis presents a study, which predicts the vibratory response of Blade and develops a design for the sculpture to be built at the largest practical economic size.
Len Lye's aesthetic requirements stipulate that the vibratory blade form of the scaled sculpture must be geometrically similar to the original work and that static similarity should exist between the original and the scaled blades.
Dimensionless formulae are derived and used to study the influence of design parameters and increasing size on structural properties such as natural frequencies, blade forces and moments, and system power requirements. For a solid metal blade of rectangular cross section it is found that the size, which Blade may be scaled, is limited by the magnitude of the bending stresses in the blade material.
Len Lye's specification imposes a set of requirements and constraints on the design, which in addition to economic constraints leads to a variational study which maximises the number of performances per dollar expended on blade materials with increasing size. As a result of this study a titanium alloy 6AI/4V is selected for the scaled blade with a nominal blade length is 3.355m.
To test the validity of the design, frequencies and mode shapes were calculated and a numerical simulation performed. The exact solution for the natural bending frequencies and mode shapes for the blade and the wand are obtained using simple beam theory. The Rayleigh Ritz method is used to calculate the plate frequencies and mode shapes for the blade. The calculated frequencies and mode shapes include the effects of the longitudinal gravitational loading. In this study they are the second and third blade bending frequencies and the third plate mode Len Lye described as the desirable vibrating single and double harmonic blade forms and the shimmering frequency respectively.
For the simulation a mathematical model is developed to describe the dynamics of the interaction of the blade and the wand. The model predicted a swinging phenomenon, which Lye observed in the performance of Blade at the prototype size and regarded as undesirable. A system configuration for the scaled Blade involving a lighter more flexible wand and modified ground motion characteristics predicted a significant reduction of this swinging phenomenon and is incorporated in the design.
Features in the design of the mechanism for the original sculpture were found to be unsatisfactory so a new improved mechanism concept was developed.
The complete design was produced and the system was manufactured and built. The performance of the scaled Blade is found to be consistent with the prediction from the mathematical model.
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Coles, Thomas Michael Kyte. "Model simplification of chemical kinetic systems under uncertainty." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65183.
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Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 103-108).
This thesis investigates the impact of uncertainty on the reduction and simplification of chemical kinetics mechanisms. Chemical kinetics simulations of complex fuels are very computationally expensive, especially when combined with transport, and so reduction or simplification must be used to make them more tractable. Existing approaches have been in an entirely deterministic setting, even though reaction rate parameters are generally highly uncertain. In this work, potential objectives under uncertainty are defined and then a number of studies are made in the hope of informing the development of a new uncertainty-aware simplification scheme. Modifications to an existing deterministic algorithm are made as a first step towards an appropriate new scheme.
by Thomas Michael Kyte Coles.
S.M.
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Fox, Justin M. 1981. "Fully-kinetic PIC simulations for Hall-effect thrusters." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41733.
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Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2007.Includes bibliographical references (p. 173-177).
In recent years, many groups have numerically modeled the near-anode region of a Hall thruster in attempts to better understand the associated physics of thruster operation. Originally, simulations assumed a continuum approximation for electrons and used magnetohydrodynamic fluid equations to model the significant processes. While these codes were computationally efficient, their applicability to non-equilibrated regions of the thruster, such as wall sheaths, was limited, and their accuracy was predicated upon the notion that the energy distributions of the various species remained Maxwellian at all times. The next generation of simulations used the fully-kinetic particle-in-cell (PIC) model. Although much more computationally expensive than the fluid codes, the full-PIC codes allowed for non-equilibrated thruster regions and did not rely on Maxwellian distributions. However, these simulations suffered for two main reasons. First, due to the high computational cost, fine meshing near boundaries which would have been required to properly resolve wall sheaths was often not attempted. Second, PIC is inherently a statistically noisy method and often the extreme tails of energy distributions would not be adequately sampled due to high energy particle dissipation. The current work initiates a third generation of Hall thruster simulation. A PIC-Vlasov hybrid model was implemented utilizing adaptive meshing techniques to enable automatically scalable resolution of fine structures during the simulation. The code retained the accuracy and versatility of a PIC simulation while intermittently recalculating and smoothing particle distribution functions within individual cells to ensure full velocity space coverage. A non-Monte Carlo collision technique was also implemented to reduce statistical noise.
(cont.) This thesis details the implementation and thorough benchmarking of that new simulation. The work was conducted with the aid of Delta Search Labs' supercomputing facility and technical expertise. The simulation was fully-parallelized using MPI and tested on a 128 processor SGI Origin machine. We gratefully acknowledge that funding for portions of this work has been provided by the United States Air Force Research Laboratory and the National Science Foundation.
by Justin M. Fox.
S.M.
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Korkmaz, Koray Arkon Cemal. "An analytical study of the design potentials in kinetic architecture/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/doktora/mimarlik/T000485.doc.
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Benson, Brian C. "Design and Analysis of a Rapid Kinetic Energy Transmission Mechanism." Digital WPI, 2011. https://digitalcommons.wpi.edu/etd-theses/327.
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The rapid release of energy in mechanisms is often limited by conversion of potential energy to kinetic energy. The use of a flywheel to store energy over time eliminates this constraint. Using this principle, a lightweight and compact energy transmission mechanism has been developed for robotic combat applications. The purpose of the proposed design is to throw an opposing robot ten or more feet into the air. This design incorporates a flywheel, a self-resetting dog clutch with built in shock absorbing rubber for impact mitigation, and an optimized four-bar linkage to deliver the energy. A mathematical model of the dynamic system has been developed to analyze and aid in the design process. Testing of subsystems was performed to validate the design. A final design is proposed with the recommendation that it be built and tested. A validated design is applicable to many real-world problems that require rapid kinetic energy release including reconnaissance robots required to hop high fences.
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Brown, Ashlie (Ashlie M. ). "Building KiMoSin : design requirements for kinetic interfaces in protein education." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40396.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaves 18-19).
Design guidelines for tools to enhance protein education are developed and applied to a prototype tool. A literature search and personal experience suggest kinetic, tangible models fill the current gaps in protein education. Thirty-six personal interviews with biology instructors and students set a mandate for three design guidelines for appropriate kinetic, tangible tools. The guidelines - simplicity, accuracy, and intuition - form a simple mantra to guide protein education tool design. The guidelines are then used to develop the prototype of an educational model of kinesin, a simple and vital motor protein. Application of these guidelines should result in design that provides students an interactive medium to discover the world of proteins. The prototyped kinesin model, nicknamed KiMoSin, shows promise of fulfilling that goal.
by Ashlie Brown.
S.B.
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Fox, Michael A. (Michael Allan). "Novel affordances of computation to the design processes of kinetic structures." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10995.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1996.Includes bibliographical references (leaves 44-45).
This paper is a discourse into the relationship between the process, computational tools and the role which symbolic structure can play in both. I argue the relationship of the process and tools is dialectic, whereby the tools we utilize in design develop new heuristics, the methodologies in tum, if reflectively understood, can be more aptly facilitated through the development of novel tools. The tools and the process then evolve together. A theory is laid out exploring the human visual information processing systems pertinence to the limitations in mental three-dimensional imaging and transformation operations relevant to the operations of drawing and mental visualization within the architectural design processes, substantiating the designers "necessity" to d raw (by traditional means, but more importantly here, through the inclusive integration of CAD within the process). The "necessity" to draw is explored as a re-presentational process to the visual system predicated upon the existence of a structured internal "library" of diagram-like representations. I argue that the ways we utilize such idiosyncratic libraries is predicated upon the ways in which we go about structuring the perceived "experienced" world around us into "symbol systems". And finally, the ways we utilize our reflective understanding of the heuristic transformations of these "symbols" within the design process in the context of a CAD environment are explored as a means to an enhanced understanding of that which is being designed and consequently as a vehicle for the development of future CAD systems to better facilitate such methodologies of designing. A personal design process of several kinetic structures is carried out in order to arrive at a localized process analysis within computer-aided design environment. Through an interactive, reflective process analysis, conclusions are drawn as to the affordances and limitations of such tools as suggestive of the operations a CAD environment might perform so as to better foster future methodologies of designing. The design "experiments" are utilized as a vehicle to understand the process. Specifically three kinetic projects are exploited for the prototypical "operations" they display. When difficulties or mental limitations are encountered with the operations, specific "tools" are developed to facilitate the limitation or to overcome the problem.
by Michael A. Fox.
M.S.
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Kislyak, Anastasia. "In-depth kinetic understanding and design of [4+4] anthracene photocycloadditions." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/226945/1/Anastasia_Kislyak_Thesis.pdf.
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This thesis pioneers the development of a model to correlate dynamic polymer network structures and their molecular changes in the presence of a light stimulus with the observed mechanical properties. Initially, a reversible anthracene photocycloaddition reaction model is introduced for predicting experimental data in solution and is subsequently extended towards the intramolecular crosslinking of single polymer chains. The model can predict the reaction progress and the radius of gyration of the folded polymers by using chemical reactivities corrected for confinement effects. Finally, the thesis explores how these novel approaches aid the modelling of dynamic polymer network synthesis.
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Wierzbicki, Madalina Nicoleta. "Topologies and design methods for folding kinetic structures : expanding the architectural paradigm." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/45748.
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Allcock, Gillian C. "The statistical aspects of the analysis and design of enzyme kinetic studies." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366536.
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Naifar, Slim. "Model Based Design of a Magnetoelectric Vibration Converter from Weak Kinetic Sources." Universitätsverlag Chemnitz, 2018. https://monarch.qucosa.de/id/qucosa%3A32774.
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The main challenge in the design of vibration energy harvesters is the optimization of energy outcome relative to the applied excitation to reach a higher efficiency in spite of the weakness of ambient energy sources. One promising principle of vibration converters is magnetoelectricity due to the outstanding properties of magnetostrictive and piezoelectric laminate composites, which provide interesting possibilities to harvest energy from low amplitude and low frequency vibration with relatively high energy outcome. For these devices, ensuring high deformations in the magnetostricive layers, improvement of the magnto-mechanical and the electro-mechanical couplings are highly required for the optimization of the energy outcome.
This thesis primarily aims to develop a model based harvester design for magnetoelectric (ME) converters. Based on a comprehensive understanding of the complex energy flow in magnetoelectric transducers, several design parameters are investigated. For instance, magnetostriction in a Terfenol-D plate is investigated by means of atomic force microscopy under similar conditions as within magnetoelectric transducers. A novel measurement approach was successfully developed to detect the evolution of magnetic domains and measure deformations in a Terfenol-D plate in response to externally non-uniform applied magnetic fields.
Furthermore, a finite element model is developed to predict the induced voltage in the ME transducer as a response to the magnet’s displacement, corrected based on atomic force microscopy measurements, and used for the design of the harvester. The presented three- dimensional model takes into consideration the nonlinear behaviour of the magnetostrictive and piezoelectric materials. Additionally, three novel converters having different magnetic circuits are designed and analysed analytically based on Lindstedt-Poincaré method. The effects of the structure parameters, such as the nonlinear magnetic forces, the magnetic field distribution and the resonance frequency are discussed, and the electric output performances of the three designed converters are evaluated.
In order to improve both mechanical and electrical coupling between the piezoelectric and the magnetostrictive layers, a bonding technique at room temperature is proposed which uses conductive polymer nanocomposites. Two magnetoelectric transducers are fabricated based on this technique having 1 wt.% and 2 wt.% concentration of multiwalled carbon nanotubes in epoxy resin. Another magnetoelectric transducer is fabricated by a classical technique for comparison purposes.
In order to validate the design, a series of demonstrators are designed and fabricated according to the simulation and optimization results. The proposed design is composed by a cantilever beam, a magnetic circuit with several magnet arrangements and a magnetoelectric transducer, which is formed by a piezoelectric PMNT plate bonded to two magnetostrictive Terfenol-D layers. In this design, external vibrations are converted to magnetic field changes acting on the magnetostrictive layers leading to deformations, which are transmitted directly to the piezoelectric layer.
The converters are tested under harmonic excitations and real vibration profiles reproduced by an artificial vibration source. Different parameters were investigated experimentally including the magnetic forces between the transducer and the magnetic circuit and the used bonding technique. Tuning the resonance frequency of the ME converter is also addressed using a simple screw/nut system, which allows to control the relative position and therefore the magnetic forces between the magnetic circuit and the transducer.
The magnetoelectric transducer bonded with 2 wt.% concentration of multiwalled carbon nanotubes shows better output performances than the two other ME transducers under similar excitations. A maximum power output of 2.42 mW is reached under 1 mm applied vibration at 40 Hz. This performance presents an improvement of minimum 20 % of the reached energy outcome by other magnetoelectric vibration converters using single ME transducer at comparable applied excitations.Die größte Herausforderung bei der Konstruktion von Vibrations-Energiewandlern ist die Optimierung der gewonnenen Energie im Verhältnis zur angewandten Anregung, um trotz schwacher Umgebungsenergiequellen einen hohen Wirkungsgrad zu erreichen. Ein vielversprechendes Prinzip von Vibrationswandlern ist die Magnetoelektrizität aufgrund der hervorragenden Eigenschaften von magnetostriktiven und piezoelektrischen Verbundwerkstoffen, die interessante Möglichkeiten bieten, Energie aus niederfrequenten Schwingungen mit kleinen Amplituden zu gewinnen. Bei diesen Wandlern ist die Sicherstellung hoher Verformungen in den magnetostriktiven Schichten, die Verbesserung der magnetisch-mechanischen und der elektromechanischen Kopplungen für die Optimierung des Energieertrages sehr wichtig. Diese Arbeit zielt in erster Linie auf die Entwicklung eines modellbasierten Entwurfs für magnetoelektrische (ME) Wandler ab. Basierend auf einem umfassenden Verständnis des komplexen Energieflusses in magnetoelektrischen Wandlern werden mehrere Entwurfsparameter untersucht. So wird beispielsweise die Magnetostriktion in einer Terfenol-D-Platte mittels Rasterkraftmikroskopie unter ähnlichen Bedingungen untersucht wie in magnetoelektrischen Wandlern. Dabei wurde eine neuartige Messmethode erfolgreich entwickelt, um die Entwicklung von magnetischen Domänen zu erfassen und die Deformation in einer Terfenol-D-Platte als Reaktion auf extern ungleichmäßig angelegte Magnetfelder zu messen. Darüber hinaus wird ein Finite-Elemente-Modell entwickelt, um die induzierte Spannung im ME-Wandler als Reaktion auf die Verschiebung des Magneten vorherzusagen, welches auf der Grundlage von Atomkraftmikroskopie Messungen korrigiert und für den Entwurf des Energiewandlers verwendet wird. Das vorgestellte dreidimensionale Modell berücksichtigt das nichtlineare Verhalten der magnetostriktiven und piezoelektrischen Materialien. Zusätzlich werden drei neuartige Wandler mit unterschiedlichen Magnetkreisen nach dem Lindstedt-Poincaré Verfahren konzipiert und analytisch analysiert. Die Auswirkungen der Strukturparameter, wie die nichtlinearen Magnetkräfte, die Magnetfeldverteilung und die Resonanzfrequenz, werden diskutiert und die elektrischen Ausgangsleistungen der drei ausgelegten Wandler ausgewertet. Um die mechanische und elektrische Kopplung zwischen der piezoelektrischen und der magnetostriktiven Schicht zu verbessern, wird eine bei Raumtemperatur prozessierbare Verbindungstechnik vorgeschlagen, bei der leitfähige Nanokomposite verwendet werden. Zwei magnetoelektrische Wandler werden basierend auf dieser Technik mit einer Konzentration von 1 wt.% und 2 wt.% an mehrwandigen Kohlenstoff-Nanoröhren in Epoxidharz hergestellt. Ein weiterer magnetoelektrischer Wandler wurde zu Vergleichszwecken mit einer klassischen Technik hergestellt. Für die Validierung des Entwurfes wird eine Reihe von Demonstratoren entsprechend den Simulations- und Optimierungsergebnissen konstruiert und gefertigt. Der vorgeschlagene Entwurf besteht aus einem Trägerbalken, einem Magnetkreis mit mehreren Magnetanordnungen und einem magnetoelektrischen Wandler, der aus einer piezoelektrischen PMNT-Platte besteht, die mit zwei magnetostriktiven Terfenol-D-Schichten verbunden ist. Bei dieser Konstruktion werden externe Schwingungen in Magnetfeldänderungen umgewandelt, die auf die magnetostriktiven Schichten wirken und zu Verformungen führen, die direkt auf die piezoelektrische Schicht übertragen werden. Die Wandler werden unter harmonischen Anregungen und mit realen Schwingungsprofilen getestet, die von einer künstlichen Schwingungsquelle reproduziert werden. Verschiedene Parameter wurden experimentell untersucht, darunter die magnetischen Kräfte zwischen dem Wandler und dem Magnetkreis sowie die verwendete Verbindungstechnik. Die Abstimmung der Resonanzfrequenz des ME-Wandlers erfolgt ebenfalls über ein einfaches Schrauben-Mutter-System, das es ermöglicht, die relative Position und damit die magnetischen Kräfte zwischen Magnetkreis und Wandler zu steuern. Der magnetoelektrische Wandler, der mit einer Konzentration von 2 wt.% mehrwandiger Kohlenstoff-Nanoröhrchen verbunden ist, zeigt bessere Ausgangsleistungen als die beiden anderen ME-Wandler bei ähnlichen Anregungen. Eine maximale Ausgangsleistung von 2,42 mW wird bei 1 mm angelegter Vibration bei 40 Hz erreicht. Diese Leistung stellt eine Verbesserung von mindestens 20 % im Vergleich zu anderen magnetoelektrischen Schwingungsumrichtern dar, welche mit einem einzigen ME-Wandler bei vergleichbaren Anregungen getestet werden.
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Hone, Christopher Andrew. "Evolution of kinetic motifs through rate-based experimental design in flow reactors." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/12202/.
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Continuous processing is revolutionising drug discovery and manufacture. Currently there is no established robust scale-up workflow for the development of flow processes in the pharmaceutical manufacturing sector. This presents a significant development risk for the implementation of continuous processing within the pharmaceutical industry in comparison to traditional batch processing, which limits the uptake of flow processes within this industry. The primary goal of this thesis is to devise and demonstrate a development workflow that maximises both understanding and the degree of optimisation of the process operating conditions for a reaction. In particular, this thesis develops an experimental design and fitting strategy, termed rate-based design of experiments (rDoE), which can be applied within the development constraints. The concept of a kinetic motif is applied as a way to represent the time-dependent behaviour in a single-step or multistep reaction system. Initially a workflow for the evolution of kinetic motifs in flow through a rate-based experimental design methodology is established using a Paal‒Knorr reaction. The experimental design investigates process-relevant conditions, and focuses on the regions where most change is observed to improve confidence. The established kinetic model is successfully validated in batch and at a larger scale in an Alfa Laval ART® Plate Reactor. A three-level definitive screening design is combined with reaction profiling (rDSD) to measure the reaction kinetics for a multistep Friedel‒Crafts heteroarylation reaction. The responses are measured by UPLC analysis. The kinetic motif acts as a simplified representation of the system to reveal a sweet spot operating region which is not predicted by statistical models. An automated kinetic platform is developed with at-line HPLC analysis at the reactor outlet, and aromatic nucleophilic reactions are demonstrated using the approach. The reactions are multistep networks which makes prediction of the kinetic parameters for individual pathways difficult. This problem is overcome by exploring a wide design space, from mild to very aggressive conditions using a new linear flow ramp gradient approach. The approach gave high confidence in the established kinetic model. The workflow is applied to a telescoped multiphase process. The example shows that a rDoE approach is fit-for-purpose for establishing rate-based behaviour, even for a multiphase system. The model developed is used to successfully identify the experiments that give the best results at a larger scale.
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Sandström, Anders G., Ylva Wikmark, Karin Engström, Jonas Nyhlén, and Jan-E. Bäckvall. "Combinatorial reshaping of the Candida antarctica lipase A substrate pocket for enantioselectivity using an extremely condensed library." Stockholms universitet, Institutionen för organisk kemi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-74997.
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A highly combinatorial structure-based protein engineering method for obtaining enantioselectivity is reported that results in a thorough modification of the substrate binding pocket of Candida antarctica lipase A (CALA). Nine amino acid residues surrounding the entire pocket were simultaneously mutated, contributing to a reshaping of the substrate pocket to give increased enantioselectivity and activity for a sterically demanding substrate. This approach seems to be powerful for developing enantioselectivity when a complete reshaping of the active site is required. Screening toward ibuprofen ester 1, a substrate for which previously used methods had failed, gave variants with a significantly increased enantioselectivity and activity. Wild-type CALA has a moderate activity with an E value of only 3.4 toward this substrate. The best variant had an E value of 100 and it also displayed a high activity. The variation at each mutated position was highly reduced, comprising only the wild type and an alternative residue, preferably a smaller one with similar properties. These minimal binary variations allow for an extremely condensed protein library. With this highly combinatorial method synergistic effects are accounted for and the protein fitness landscape is explored efficiently.
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Al, Wahabi Saeed M. H. "Conversion of methanol to light olefins on SAPO-34: kinetic modeling and reactor design." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1579.
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In this work, the reaction scheme of the MTO process was written in terms of elementary steps and generated by means of a computer algorithm characterizing the various species by vectors and Boolean relation matrices. The number of rate parameters is very large. To reduce this number the rate parameters related to the steps on the acid sites of the catalyst were modeled in terms of transition state theory and statistical thermodynamics. Use was made of the single event concept to account for the effect of structure of reactant and activated complex on the frequency factor of the rate coefficient of an elementary step. The Evans-Polanyi relation was also utilized to account for the effect of the structure on the change in enthalpy. The structure was determined by means of quantum chemical software.
The number of rate parameters of the complete reaction scheme to be determined from experimental data is thus reduced from 726 to 30. Their values were obtained from the experimental data of Abraha by means of a genetic algorithm involving the Levenberg-Marquardt algorithm and combined with sequential quadratic programming.
The retained model yields an excellent fit of the experimental data. All the parameters satisfy the statistical tests as well as the rules of carbenium ion chemistry. The kinetic model also reproduces the experimental data of Marchi and Froment, also obtained on SAPO-34. Another set of their data was used to introduce the deactivation of the catalyst into the kinetic equations.
This detailed kinetic model was used to investigate the influence of the operating conditions on the product distribution in a multi-bed adiabatic reactor with plug flow. It was further inserted into riser and fluidized bed reactor models to study the conceptual design of an MTO reactor, accounting for the strong exothermicity of the process. Multi-bed adiabatic and fluidized bed technologies show good potential for the industrial process for the conversion of methanol into olefins.
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Adams, Jonathan Weldon. "Kinetic assay of T7 activity on mutant promoters : method development and experimental design." Thesis, Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/29908.
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Saeed, Muhammad Tariq. "Application of kinetic models to the design of liquid-liquid extraction spray columns." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47638.
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Parkes, Amanda Jane. "Phrases of the kinetic : dynamic physicality as a dimension of the design process." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/51661.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2009.Includes bibliographical references (p. 161-167).
At its core, the concept of Tangible Interfaces leverages the idea of using the movement of the body as an inherent part of the human side of a human-computer interaction, assuming that bodily engagement and tactile manipulation can facilitate deeper understanding and more intuitive experiences. However, as an interaction principle in our era of digital design, motion construction and control has been underutilized and little examined as a design tool, leaving open the possibilities of motion's natural ability to draw our attention, provide physical feedback, and convey information through physical change. This dissertation postulates that the ability to experiment, prototype, and model with programmable kinetic forms is becoming increasingly important as digital technology becomes more readily embedded in our objects and environments and need for tools and systems with which to create, manipulate and finesse motion in response to computational and material input remains an under-developed design area. This thesis aims to establish principles of kinetic design through the exploration of two approaches to motion construction and manipulation: motion prototyping as a methodology for design thinking, learning and communication and physically dynamic state memory as a methodology for organic form finding and transformation in the design process.
(cont.) To demonstrate these aims, I present three interface systems: Topobo, a system for motion construction and dynamics physics education with children; Kinetic Sketchup, a system for motion construction and prototyping in architecture and product design; and Bosu, an augmented textile interface offering an experimental approach to digitally augmented organic form finding in fashion and product design.
Amanda Jane Parkes.
Ph.D.
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Foster, Michael Scott. "Design, synthesis, kinetic analysis, molecular modeling, and pharmacological evaluation of novel inhibitors of peptide amidation." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/31816.
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Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009.Committee Chair: Dr. Sheldon W. May; Committee Member: Dr. James C. Powers; Committee Member: Dr. Nicholas Hud; Committee Member: Dr. Niren Murthy; Committee Member: Dr. Stanley H. Pollock. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Jovkar, Sayed. "Optimization of experimental design in Tracer kinetic models applied to Positron Emission Tomography and Autordiography." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65387.
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Lynas, John F. "The design, synthesis and kinetic characterisation of novel inhibitors of the serine and cysteine proteases." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318767.
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Poliakov, Anton. "Peptide-Based Inhibitors of Hepatitis C Virus NS3 Serine Protease: Kinetic Aspects and Inhibitor Design." Doctoral thesis, Uppsala universitet, Institutionen för naturvetenskaplig biokemi, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4127.
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Hepatitis C is a serious disease that affects about 200 million people worldwide. No anti-HCV vaccine or specific anti-viral drugs are available today. Non-structural protein 3 (NS3) of HCV is a bifunctional serine protease/helicase, and the protease has become a prime target in the search for anti-HCV drugs. In this work, the complete HCV NS3 gene has been cloned and expressed, and the protein has been purified using affinity chromatography. An assay for measuring the protease activity of full-length NS3 protease has been developed and used for inhibition studies. A series of peptide-based inhibitors of NS3 protease varying in length, the composition of the side-chain and the N- and C-terminal groups have been studied. Potent tetra-, penta- and hexapeptide inhibitors of the NS3 protease were discovered. Hexapeptides with an acyl sulfonamide C-terminal residue were the most potent inhibitors of the NS3 protease, having nanomolar Ki-values. The selectivity of the inhibitors was assessed using other serine and cysteine proteases. NS3 protease inhibitors with electrophilic C-terminal groups were non-selective while those comprising a C-terminal carboxylate or acyl sulfonamide group were selective. All inhibitors with a small hydrophobic P1 side-chain residue were non-selective for the NS3 protease, being good inhibitors of human leukocyte elastase. This result highlights the importance of the P1 residue for inhibitor selectivity, which stems from the major role of this residue in determining substrate specificity of serine proteases. Electrophilic inhibitors often cause slow-binding inhibition of serine and cysteine proteases. This was observed with other proteases used in our work but not with NS3 protease, which indicates that mechanism of inhibition of NS3 protease by electrophilic inhibitors may not involve formation of a covalent bond. The structure-activity relationships obtained in this work can be used for improvement of peptide-based inhibitors of HCV NS3 protease towards higher inhibitory potency and selectivity.
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Blauth, Florian [Verfasser], Jürgen [Gutachter] Stutzki, and Joachim [Gutachter] Hemberger. "Design and measurement of superconducting microwave kinetic inductance detectors / Florian Blauth ; Gutachter: Jürgen Stutzki, Joachim Hemberger." Köln : Universitäts- und Stadtbibliothek Köln, 2019. http://d-nb.info/1199004715/34.
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Kassabian, Paul E. (Paul Edward) 1974. "On the design of a kinetic adaptive structural surface with reference to nature, form and simplicity." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/29568.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.Includes bibliographical references (p. 89-90).
The central thrust of this thesis is that there is much to learn from Nature. What surrounds us, and has been with us from the beginning of time, still has many insights to offer, if we are only willing to look. In Nature, shape is cheaper than material. Forces and form are continuously linked and the concept of adaptability is central to survival. Many of our designs, in contrast, have been over-designed, unresponsive and unchangeable. This thesis covers how well thought through form can yield impressive benefits which, in combination with adaptability, can create structures that are efficient as well as beautiful. Specific forms in Nature are discussed as well relevant historical examples from the built environment; including new work in deployable structures. As an example of these concepts, a kinetic adaptive structural surface was designed and built. This responded to applied loads by actively changing its shape. The thesis concludes with a discussion on emergence as one of the ways ahead for structural design that involves distributed sensing and control.
Paul E. Kassabian.
S.M.
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Critchfield, Brian L. "Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1670.pdf.
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Spencer, Timothy David. "Design of Len Lye's blade at the largest economic size." Thesis, University of Canterbury. Mechanical Engineering, 2014. http://hdl.handle.net/10092/9368.
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Len Lye was born in Christchurch, New Zealand, in 1901. Lye was an avid enthusiast of kinetic sculpture and experimental film. In 1965 Lye built a prototype for a kinetic sculpture called Blade that he intended would be a much larger work.
In 1996, Dr. Shayne Gooch of the University of Canterbury embarked on a research contract that saw the fruition of Lye’s Blade at a scale previously unachieved. This work was given the name Big Blade.
This thesis provides a study into the maximum realisable scale of Blade using technology and materials available today. A new pivoting clamp design is tested and assessed using a small scale Blade sculpture built at the University of Canterbury and used as a test rig.
Advancements in technology, material availability and manufacturing techniques lead to a comprehensive fatigue study of the new clamp design. Stresses are measured at the critical stress location in the blade material and a new maximum economic scale of Blade is suggested. The new sculpture requires a blade material that measures 10024mm x 1080mm x 22mm. The visible blade length is 8424mm. The new sculpture is called Giant Blade.
A critical aesthetic component for Len Lye’s performance of Blade is the mode shapes formed by the blade material. Specifically, the second and third bending modes (Lye’s single and double harmonic) and the first torsional bending mode (Lye’s shimmering frequency). These frequencies are calculated using the new pivoting clamp design to ensure that these sections of the performance are maintained in Giant Blade.
An important requirement of the new sculpture drive mechanism is the capability to reduce the amplitude of shuttle oscillation dynamically during Blade performances. This capability allows bending stresses in the blade material to be reduced in the third bending mode of vibration without halting the performance to adjust the shuttle oscillation amplitude. Four dynamically adjustable variable stroke mechanisms are presented and compared using the methods of Pahl and Beitz. A suitable mechanism for Giant Blade is selected and a proposed arrangement for the new sculpture is provided.
An embodiment design is presented for Giant Blade. This embodiment design consists of a new pivoting clamp design and the proposed variable stroke mechanism. Further work includes the design of a mechanism to support the ball and wand assembly.
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Daoudi, Gabriele Yunes. "Development of a Kinetic Energy Recovery System for a Rotary Turret Machine." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16595/.
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The scope of the Kinetic Energy Recovering Systems is to store a certain amount
of energy during the system’s nominal operation by recovering it from the brakes
and reuse it later.
The scope of this thesis will be studied the development of such system on an automatic
machine. The field of application is known as "Green Automation", that
became popular during the last decade.
The machine analyzed is a rotary turret one that operates in the beverage automation.
Its role is to apply a particular type of cap on the cans to improve the hygiene
and the aesthetics.
The problem has been tackled by elaborating mathematical models of the physical
systems, performing different tests and data logging, applying Parameter Identification
Algorithms and finally developing the solution. It has been also performed a
brief analysis of the different available technologies to realize the system.The project
has been validated performing simulations on the models.
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Yu, Jie. "Novel swing arm mechanism design for trailing edge flaps on commercial airliner." Thesis, Cranfield University, 2008. http://dspace.lib.cranfield.ac.uk/handle/1826/9586.
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This thesis will describe the works had been done by the author in the Flying Crane
aircraft group design project and the new design of a novel swing arm mechanism
which can be applied in the trailing edge high lift devices for this aircraft concept.
Flying Crane aircraft is a new generation commercial airliner concept as the result of
group design project conducted by China Aviation Industry Corporation I (AVIC I) and
Cranfield University. At the end of the group design project, parameters such as take-off
and landing distance, trailing edge flap type and deflection in take-off and landing
configuration of the Flying Crane concept have been determined. These parameters are
design input of the novel trailing edge high lift device mechanism for this aircraft
concept.
The idea of this innovative mechanism comes from the research achievement of a
previous MSc student, Thomas Baxter, which applied swing arm mechanism into a
passenger aircraft's leading edge slat. This thesis applied this idea to trailing edge flap
and modeled the mechanism on CATIA software to yield a kinematic simulation for the
purpose of check motion trail and force transfer in this mechanism. Relevant works
such as actuation, mass and stress analysis are also involved.
As the result of this research project, it was found that swing arm mechanism trends to
require relatively small fairings for supports and attachments due to its high stowed
space utilizing efficiency. Initial mass estimation carried out in this thesis also indicates
that the new design takes advantage in terms of weight comparing with traditional
trailing edge flap mechanisms. Thus. swing arm mechanism is supposed to show great
competitive potential for commercial airliner's trailing edge flaps after further analysis
has been done in the detail design phase.
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Gerasimaitė, Rūta. "A directed evolution design of target specificity and kinetic analysis of conformational transitions in the HhaI methyltransferase." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110519_082240-87105.
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DNA cytosine-5 methyltransferases (MTases) recognize short DNA sequences and catalyze the transfer of the methyl group from the cofactor AdoMet to the C5-position of a target cytosine. In this work both these aspects of the MTase mechanism have been addressed. First, using rational protein design and directed evolution approaches the specificity of the HhaI MTase, GCGC, has been changed to GCG by functional elimination of one of the two target recognition elements. In addition, the introduced structural changes endowed the MTase with the ability to transfer extended groups from synthetic cofactor analogs, providing the first example of a dual specificity change in a DNA MTase.
Second, the kinetics of fast pre-catalytic conformational transitions in the MTase and DNA has been investigated. A new method to follow the target cytosine flipping and its subsequent covalent activation has been proposed, which allows a direct real-time observation of these processes by monitoring associated UV absorbance changes in a chemically unperturbed DNA. These studies for the first time demonstrate that the flipping of the target cytosine and the closure of the catalytic loop in the enzyme occur simultaneously, whereas the covalent activation of the target cytosine and the transfer of the methyl group are temporally distinct steps in the catalytic cycle of M.HhaI. Since the new method is based on the general phenomenon of hyperchromicity, it is thus applicable for studies of other systems... [to full text]DNR citozino-5 metiltransferazės (MTazės) atpažįsta specifines DNR sekas ir katalizuoja metilgrupės pernešimą nuo kofaktoriaus AdoMet ant taikinyje esančio citozino. Šiame darbe nagrinėjami abu MTazių veikimo mechanizmo aspektai. Baltymų inžinerijos ir kryptingos evoliucijos metodais pašalinant vienos iš dviejų taikinio atpažinimo kilpų funkciją, MTazės HhaI atpažįstamas taikinys GCGC pakeistas į GCG. Dėl įvestų struktūros pakeitimų nauja unikalaus specifiškumo MTazė efektyviai katalizuoja ne tik metilo, bet ir didesnių grupių pernešimą nuo sintetinių kofaktoriaus analogų, ir gali tapti naudingu molekulinės biologijos įrankiu. Katalitinės reakcijos metu MTazės kilpa užsidaro, apglėbdama surištą DNR, o taikinio citozinas išsukamas iš DNR spiralės ir aktyvuojamas, kovalentiškai prisijungiant katalitiniam cisteinui. Šiems greitiems prieškatalitiniams procesams tirti buvo panaudotas naujas metodas, leidžiantis realiu laiku stebėti M.HhaI sąlygotą citozino išsukimą bei kovalentinę aktyvaciją, registruojant mažus UV absorbcijos pokyčius gamtinį substratą atitinkančioje DNR. Pirmą kartą parodyta, kad M.HhaI katalizuojamoje reakcijoje citozino išsukimas ir katalitinės kilpos užsidarymas vyksta sinchroniškai, o kovalentinė citozino aktyvacija ir metilgrupės pernešimas yra kinetiškai netapačios katalitinio ciklo stadijos. Kadangi naujasis metodas remiasi fundamentine nukleorūgščių savybe – hiperchrominiu efektu, todėl jis gali būti naudojamas ir kitų DNR bazę išsukančių baltymų... [toliau žr. visą tekstą]
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Wilkinson, Nina. "An analysis of intrinsically disordered proteins using hidden Markov models and experimental design of stochastic kinetic models." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/2846.
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An intrinsically disordered protein (IDP) is a protein without a stable secondary or tertiary structure and just over one third of human proteins can be described as IDPs. There has been shown to be a link between neurodegenerative diseases, cancer and protein misfolding, with many of these misfolded proteins being intrinsically disordered. These IDPs may be cytotoxic by interacting and contributing to the aggregation process, which is why cells need to regulate these proteins carefully. Research has shown that hydrophobicity and charge may be important in determining if the amino acid sequence has unstructured areas. We study the sequence structure by rst recoding amino acid sequences according to their hydrophobicity and charge and then tting a hidden Markov model using Markov chain Monte Carlo methods to analyse the sequence structure and use a power posterior analysis to determine the number of distinct transition structures. The results show there to be distinct segment types within the amino acid sequences of the FET proteins which may have biological importance. The location of these segments can be used to guide laboratory work which tests the biological signi cance of these segment types within cells. One particular segment found in the FET proteins has been linked to oncogenic fusion proteins and experimental analysis has shown a link between this segment and oncogenic activity. When conducting an experiment, an experimenter needs to determine when and under what conditions they should take measurements. Often the choice of optimal design is made with respect to some statistical criteria. The aim of this work is to determine, for a stochastic kinetic model, the optimal location of the timepoints at which observations are taken. Commonly the statistical criteria involves maximising a utility function over the prior predictive distribution of possible experimental outcomes. Current methodologies for experimental design for models with intractable likelihoods are very computationally expensive as, within the iterative search for the optimal design, the calculation of the utility function requires the determination of the parameter posterior distribution at each iteration. We show how to use delta methods and a Gaussian process as an emulator for the utility to reduce the computational cost and illustrate their application for the simple death process and the Lotka{Volterra model.
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Zhu, Dongrui. "Glass Curtain Wall Retrofit Through Modular Kinetic Facade To Design Safe, Energy Efficient, Sustainable Urban Office High-rise Facade." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1617108007657155.
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Watkins, Claire. "The Transformation of Electricity in my Brain." VCU Scholars Compass, 2004. http://scholarscompass.vcu.edu/etd/1062.
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This thesis is an exciting and enthralling story about the history of the world as seen through the eyes of Claire Watkins. The story takes place in the dusty corners of her art studio in the old confederate capital, Richmond, Virginia. Ms. Watkins leads her audience through such unsuspecting places as her brain, the life of an African Dung Beetle, the center of an atom and the dark reaches of outer space. The story is inspirational and thought provoking. It will force you to see the world as an interconnected web that weaves your life together with the cosmos. A must read for the summer!"Truly exceptional
a wonderful Thesis
highly recommended!" - Ruby Westcoat"I never thought of the world quite like that
now I see everything in a new and electrifying way." - Timothy Devoe"Once again she proves to be my favorite contemporary artist and author" - Virgil Hale Rhames
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Szost, Blanka Angelika. "Hydrogen trapping in bearing steels : mechanisms and alloy design." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/244934.
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Hydrogen embrittlement is a problem that offers challenges both to technology and to the theory of metallurgy. In the presence of a hydrogen rich environment, applications such as rolling bearings display a significant decrease in alloy strength and accelerated failure due to rolling contact fatigue. In spite of these problems being well recognised, there is little understanding as to which mechanisms are present in hydrogen induced bearing failure. The objective of this thesis are twofold. First, a novel alloy combining the excellent hardness of bearing steels, and resistance to hydrogen embrittlement, is proposed. Second, a new technique to identify the nature of hydrogen embrittlement in bearing steels is suggested. The new alloy was a successful result of computer aided alloy design; thermodynamic and kinetic modelling were employed to design a composition and heat treatment combining (1) fine cementite providing a strong and ductile microstructure, and (2) nano-sized vanadium carbide precipitates acting as hydrogen traps. A novel technique is proposed to visualise the migration of hydrogen to indentation-induced cracks. The observations employing this technique strongly suggest that hydrogen enhanced localised plasticity prevails in bearing steels. While proposing a hydrogen tolerant bearing steel grade, and a new technique to visualize hydrogen damage, this thesis is expected to aid in increasing the reliability of bearings operating in hydrogen rich environments.
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Garcia, Sandrine. "Experimental Design Optimization and Thermophysical Parameter Estimation of Composite Materials Using Genetic Algorithms." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/28076.
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Thermophysical characterization of anisotropic composite materials is extremely important in the control of today fabrication processes and in the prediction of structure failure due to thermal stresses. Accuracy in the estimation of the thermal properties can be improved if the experiments are designed carefully. However, on one hand, the typically used parametric study for the design optimization is tedious and time intensive. On the other hand, commonly used gradient-based estimation methods show instabilities resulting in nonconvergence when used with models that contain correlated or nearly correlated parameters.
The objectives of this research were to develop systematic and reliable methodologies for both Experimental Design Optimization (EDO) used for the determination of thermal properties, and Simultaneous Parameter Estimation (SPE). Because of their advantageous features, Genetic Algorithms (GAs) were investigated for use as a strategy for both EDO and SPE. The EDO and SPE approaches used involved the maximization of an optimality criterion associated with the sensitivity matrix of the unknown parameters, and the minimization of the ordinary least squares error, respectively. Two versions of a general-purpose genetic-based program were developed: one is designed for the analysis of any EDO / SPE problems for which a mathematical model can be provided, while the other incorporates a control-volume finite difference scheme allowing for the practical analysis of complex problems. The former version was used to illustrate the genetic performance on the optimization of a difficult mathematical test function.
Two test cases previously solved in the literature were first analyzed to demonstrate and assess the GA-based {EDO/SPE} methodology. These problems included the optimization of one and two dimensional designs for the estimation at ambient temperature of two and three thermal properties, respectively (effective thermal conductivity parallel and perpendicular to the fibers plane and effective volumetric heat capacity), of anisotropic carbon/epoxy composite materials. The two dimensional case was further investigated to evaluate the effects of the optimality criterion used for the experimental design on the accuracy of the estimated properties.
The general-purpose GA-based program was then successively applied to three advanced studies involving the thermal characterization of carbon/epoxy anisotropic composites. These studies included the SPE of successively three, seven and nine thermophysical parameters, with for the latter case, a two dimensional EDO with seven experimental key parameters. In two of the three studies, the parameters were defined to represent the dependence of the thermal properties with temperature. Finally, the kinetic characterization of the curing of three thermosetting materials (an epoxy, a polyester and a rubber compound) was accomplished resulting in the SPE of six kinetic parameters.
Overall, the GA method was found to perform extremely well despite the high degree of correlation and low sensitivity of many parameters in all cases studied. This work therefore validates the use of GAs for the thermophysical characterization of anisotropic composite materials. The significance in using such algorithms is not only the solution to ill-conditioned problems but also, a drastically cost savings in both experimental and time expenses as they allow for the EDO and SPE of several parameters at once.Ph. D.
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Lamprecht, Florian [Verfasser], and Karsten [Akademischer Betreuer] Rippe. "Kinetic design of the JAK-STAT1 pathway and MYCN impact on cell cycle decisions in neuroblastoma / Florian Lamprecht ; Betreuer: Karsten Rippe." Heidelberg : Universitätsbibliothek Heidelberg, 2012. http://d-nb.info/1177040468/34.
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Smith, Stephanie A. "Design of a biological system to select for alterations in the key kinetic properties of ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) /." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486463321626482.
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Ahmed, Warsama. "Nitrifying Moving Bed Biofilm Reactors at Low Temperatures and Cold Shock Conditions: A Kinetic, Biofilm and Microbiome Study." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41196.
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The nitrification process, the biologically mediated process of ammonia treatment in water resources recovery facilities (WRRF), remains the most common treatment process to mitigate the adverse effects of effluent ammonia discharges in surface water. However, it is well established that the temperature-sensitive process of nitrification remains hindered at low temperatures in conventional suspended growth technologies; specifically, passive treatment systems such as the lagoons, representing over 50% of Canadian treatment facilities in operation. As such, nitrification in lagoon facilities remains unreliable during the cold seasons with no nitrification occurring at 1°C. In contrast to suspended growth systems, attached growth technologies such as the moving bed biofilm reactors (MBBR) have recently been proven capable of achieving significant nitrification rates at temperatures as low as 1°C and are proposed as suitable upgrade systems to the common lagoon facility to reach year-long ammonia treatment targets. As such, the main objective of this research is to investigate and expand the current knowledge by investigating the key research questions lacking in the current literature on post-carbon, low temperature nitrifying MBBR systems.
With this aim, a temperature-controlled study of attached growth nitrification kinetics was conducted to isolate the effects of low temperatures on nitrifying MBBR system performance down to 1°C. A removal rate of 98.44 ± 4.69 gN/m³d is identified as the 1°C intrinsic removal rate and the design removal rate for nitrifying MBBR systems at low temperatures. Considering this intrinsic rate at 1°C, an assessment of reactor efficiency at elevated TAN concentrations typical of non-combined sewer systems indicates that a two reactor in-series MBBR system configuration is recommended for retrofitting lagoon facilities connected to sanitary sewers.
The study of the reactor performance to temperatures as low as 1°C demonstrates a non-linear decline in removal efficiency between 10°C and 1°C, with the existence of a kinetic threshold temperature delineated between 4°C and 2°C. As such, this delineated temperature range accounts for a significant decline in the performance of low carbon nitrifying MBBR systems during the onset of the cold seasons. This research identifies new recommended Arrhenius correction coefficient values taking into account this kinetic threshold temperature, with a coefficient of 1.049 being recommended above the kinetic threshold (≥4°C) and 1.149 below the threshold temperature at 1°C. Moreover, since the elapsed time to low temperature was identified as a key factor of attached growth nitrification kinetics, a modified theta model accounting for temperature and time is proposed in this research to accurately model the rate of nitrifying MBBR systems between 4°C and 1°C.
Finally, with the severe adverse effects of sudden decreases in temperature, or cold shocks, on nitrification kinetics being previously demonstrated but not well understood, this research compares acclimatized and cold shocked MBBR reactors down to 1°C. The findings indicate 21% lower kinetics in the cold shocked reactor with reactor efficiencies never reaching those of the acclimatized reactor despite extended operation at 1°C. Thus, the research delineates the potentially lasting effects of extreme weather events such as cold air outbreaks and snowmelt periods on nitrifying MBBR system performance. On the other hand, these same findings demonstrate the resiliency of nitrifying MBBR reactors as nitrification was maintained within these systems despite being cold-shocked down from 10°C and 1°C.
This study of attached growth kinetics was coupled with an investigation of the nitrifying biofilms, biomass, and microbiome responses to low temperatures and cold shock down to 1°C to provide an understanding of the changes occurring in these systems down to the cellular level. Comparisons of acclimatized and cold shocked nitrifying biofilms responses down to 1°C were characterized by increases in biofilm thickness, increases in biomass viability; and, greater shifts in microbiome communities occurring above 4°C in the acclimatized biofilm. Considering these observations, results also indicated a significant increase in nitrifiers per carrier above 4°C. As such, these findings suggested that the bulk of nitrifying biofilm adaptation to cold temperatures occurs above 4°C, a crucial adaptation phase in acclimatized systems. This adaptation phase is shown to be lacking in cold-shocked systems, with the cold shocked biofilm and microbiome demonstrating significant differences with the acclimatized systems’ biofilm and microbiome.
This research was performed to answer the critical research questions relating to the design and operation of the post-carbon, low temperature nitrifying MBBR systems, with the first low temperature MBBR systems being scheduled to begin operation in the fall of 2020. This research expands the current knowledge on low temperature attached growth nitrification kinetics as well as cold shocked attached growth nitrification kinetics in MBBR systems down to 1°C. In addition, this research delineates the effects of low temperatures and cold shocks on the nitrifying MBBR system’s biofilms and their embedded cells.
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Dlangamandla, Nkosikho. "Design of integrated processes for a second generation biorefinery using mixed agricultural waste." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2843.
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Thesis (Doctor of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018.Lignocellulosic biomass (agro-waste) has been recommended as the most promising feedstock for the production of bioalcohols, in the biofuel industry. Furthermore, agro-waste is well-known as the most abundant organic matter in the agricultural and forestry product processing industry. However, the challenge with utilizing agro-waste as a feedstock is its highly recalcitrant structure, which limits hydrolysis to convert the holocelluloses into fermentable sugars. Conventional pre-treatment methods such as dilute acid, alkaline, thermal, hot water and enzymatic, have been used in previous studies. The challenge with these conventional methods is the generation of residual toxicants during the pretreatment process, which inhibits a high bioalcohol yield, by reducing the microbial populations’ (fermenter) ability to be metabolically proficient during fermentation. Numerous studies have been developed to improve the engineered strains, which have shown to have an ability to reduce the inhibition and toxicity of the bioalcohols produced or by-products produced during pre-treatment, while enhancing the bioalcohol production. In the present study (chapter 5), evaluation of common conventional methods for the pretreatment of the mixed agro-waste, i.e. (˃45µm to <100µm) constituted by Citrus sinensis, Malus domestica peels, corn cobs from Zea mays and Quercus robur (oak) yard waste without a pre-rinsing step at a ratio of 1:1 at 25% (w/w) for each waste material, was undertaken, focusing on hot water pre treatment followed by dilute acid (H2SO4) pre-treatment. To further pretreat the mixed agro-waste residue, cellulases were used to further hydrolyse the pre-treated agro-waste in a single pot (batch) multi-reaction process. The TRS concentration of 0.12, 1.43 and 3.22 g/L was achieved with hot water, dilute acid and cellulases hydrolysis as sequential pretreatment steps, respectively, in a single pot multi-reaction system. Furthermore, a commercial strain was used to ascertain low (C1 to C3) and high carbon content (C4+) bioalcohol production under aerobic conditions. Multiple bioproducts were obtained within 48 to 72 h, including bioethanol and 1-Butanol, 3-methyl, which were major products for this study. However, undesirable bio-compounds such as phenolics, were detected post fermentation. Since multiple process units characterised by chemical usage and high energy intensivity have been utilized to overcome delignification and cellulolysis, a sustainable, environmental benign pretreatment process was proposed using N. mirabilis “monkey cup” fluids (extracts) to also reduce fermenter inhibitors from the delignification of mixed agrowaste; a process with minimal thermo physical chemical inputs for which a single pot multi-reaction system strategy was used. Nepenthes mirabilis extracts shown to have ligninolytic, cellulolytic and xylanolytic activities, were used as an enzyme cocktail to pretreat mixed agro-waste, subsequent to the furtherance of TRS production from the agro-waste, by further using cellulase for further hydrolysis. N. mirabilis pod extracts were determined to contained carboxylesterases (529.41±30.50 U/L), β-glucosidases (251.94±11.48 U/L) and xylanases (36.09±18.04 U/L), constituting an enzymatic cocktail with a significant potential for the reduction in total residual phenolic compounds (TRPCs). Furthermore, the results indicated that maximum concentration of TRS obtainable was 310±5.19 mg/L within 168 h, while the TRPCs were reduced from 6.25±0.18 to 4.26 ±0.09 mg/L, which was lower than that observed when conventional methods were used. Overall N. mirabilis extracts were demonstrated to have an ability to support biocatalytic processes for the conversion of agro-waste to produce fermentable TRS in a single unit facilitating multiple reactions with minimised interference with cellulase hydrolysis. Therefore, the digestive enzymes in N. mirabilis pods can be used in an integrated system for a second generation biorefinery.
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Kang, Yuezhuang. "Computer-aided fixture design verification." Link to electronic thesis, 2002. http://www.wpi.edu/Pubs/ETD/Available/etd-0108102-163543.
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Thesis (M.S.)--Worcester Polytechnic Institute.Keywords: Fixture stiffness matrix; Jacobian matrix; kinetic model; geometric model; fixture design verification; stability analysis; tolerance analysis; tolerance assignment. Includes bibliographical references (p. 92-97).
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Schleicher, Simon [Verfasser], and Jan [Akademischer Betreuer] Knippers. "Bio-inspired compliant mechanisms for architectural design : transferring bending and folding principles of plant leaves to flexible kinetic structures / Simon Schleicher. Betreuer: Jan Knippers." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-104850.
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Körner, Axel Hannes [Verfasser], and Jan [Akademischer Betreuer] Knippers. "Compliant folding : design and fabrication methodology for bio-inspired kinetic folding mechanisms utilized by distinct flexible hinge zones / Axel Hannes Körner ; Betreuer: Jan Knippers." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2021. http://d-nb.info/1239648731/34.
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Alexacou, Kyriaki-Melinda [Verfasser]. "Kinetic and X-ray crystallographic studies of glycogen phosphorylase : on the way to structure based drug design for diabetes type 2 / Kyriaki-Melinda Alexacou." Berlin : Freie Universität Berlin, 2010. http://d-nb.info/1025126777/34.
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Naifar, Slim [Verfasser], Olfa [Akademischer Betreuer] Kanoun, Olfa [Gutachter] Kanoun, Jörg [Gutachter] Himmel, and Tarak [Gutachter] Bouraoui. "Model Based Design of a Magnetoelectric Vibration Converter from Weak Kinetic Sources / Slim Naifar ; Gutachter: Olfa Kanoun, Jörg Himmel, Tarak Bouraoui ; Betreuer: Olfa Kanoun." Chemnitz : Universitätsverlag Chemnitz, 2019. http://d-nb.info/1215909225/34.
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Schleicher, Simon Verfasser], and Jan [Akademischer Betreuer] [Knippers. "Bio-inspired compliant mechanisms for architectural design : transferring bending and folding principles of plant leaves to flexible kinetic structures / Simon Schleicher. Betreuer: Jan Knippers." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1088404367/34.
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Benge, G. Gregory. "Cold model of a vibrated-bed microreactor capable of varying Peclet number at fixed weight hourly space velocity providing a tool for simulating an important feature of the reaction kinetic scene in large catalytic fluid beds." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/39083.
Full textAbstract:
A cold-flow model of a vibrated-bed microreactor has been designed and tested with capability
for varying the level of gas dispersion (characterized by axial Peclet number) at a fixed weight hourly
space velocity (WHSV). A tool has thus been provided whereby an important feature (viz., gas
dispersion) of the reaction kinetic scene in large catalytic fluid beds can be simulated on a microscale,
using approximately 5 grams of catalyst.
Realization of a hot design of the microreactor (a task for another student) should permit the
industrial chemist or chemical engineer, working at laboratory bench scale, quickly and
inexpensively, to determine the sensitivity of a cataly1ic reaction to fluid-bed gas dispersion.
The new microreactor exploits the coherent-expanded (C-E) vibrated-bed state, and is perhaps
the first technical use of this state. The C-E state is achieved by subjecting a shallow layer of a fine
powder to vertical sinusoidal vibration. The microreactor comprises a rectangular horizontal duct,
12.7 mm in height, 25.4 mm in width, variable in length, and with nonporous floor and walls. The
microreactor is charged with a powder, such as fluid cataly1ic cracking (FCC) catalyst, at a compacted
depth of I mm, and is vibrated at ~15 Hertz and amplitude of ~3 mm. Under influence of this vibration, the powder expands, displaying the C-E state. Between a phase angle of ~50° and an angle of ~150°, the powder assumes a depth of ~4 mm (i.e., expanded 4-fold from its compacted
depth). Later, in each vibration cycle, the powder expands further. At ~300° phase angle, the
powder reaches ~12.7 mm (i.e., collides with the roof of the microreactor duct).Ph. D.