Browsing by Subject "Kinetic"
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Item Adaptable, kinetic, responsive, and transformable architecture : an alternative approach to sustainable design(2012-08) Lee, Joshua David; Moore, Steven A., 1945-; Dangel, UlrichThere has been a long, but disparate discourse among those responsible for our built environment about the inevitability of change on the artifacts we inhabit and those social contracts that influence their making. At a basic level doors and operable windows are an indication of the various flows that move through buildings. Innumerable “passive” and “active” strategies have been devised to allow changes to building floor plans and sections, to control sunlight and wind, to change function, etc. Hundreds, or perhaps thousands, of prototypes have been proposed and developed that change shape or composition in response to various social and environmental pressures. Though not always done with the goals of sustainability in mind, these prototypes often sought to provide increased agency for users, improved energy-efficiency and cost-effectiveness, and other commonly understood goals of sustainability. A number of books, hundreds of articles, and dozens of patents beautifully illustrate many proposed and built examples from which to learn but the descriptive terms employed are greatly varied (i.e., adaptable, animated, collapsible, deployable, enabling, evolutionary, flexible, intelligent, kinetic, manipulable, mutable, open-system, portable, protean, reconfigurable, responsive, revolving, smart, and transformable, etc.) and are therefore difficult to find. By reviewing and synthesizing the existing literature, this study provides a starting point for future research that offers both insight into how these terms have been used over time and a critique of such concerns and the exclusion of the topic within sustainability rating criteria.Item Crystallization and mutational studies of carbon monoxide dehydrogenase from moorella thermoacetica(Texas A&M University, 2004-09-30) Kim, Eun JinCarbon Monoxide Dehydrogenase (CODH), also known as Acetyl-CoA synthase (ACS), is one of seven known Ni containing enzymes. CODH/ACS is a bifunctional enzyme which oxidizes CO to CO2 reversibly and synthesizes acetyl-CoA. Recently, X-ray crystal structures of homodimeric CODH from Rhodospirillum rubrum (CODHRr) and CODH from Carboxydothermus hydrogenoformans (CODHCh) have been published. These two enzymes catalyze only the reversible oxidation of CO to CO2 and have a protein sequence homologous to that of the ? subunit of heterotetrameric ?2?2 enzyme from Moorella thermoacetica (CODHMt), formerly Clostridium thermoaceticum. Neither CODHRr nor CODHCh contain an ?-subunit as is found in CODHMt. The precise structure of the active site for acetyl-CoA synthase, called the A-cluster, is not known. Therefore, crystallization of the ? subunit is required to solve the remaining structural features of CODH/ACS. Obtaining crystals and determining the X-ray crystal structure is a high-risk endeavor, and a second project was pursued involving the preparation, expression and analysis of various site-directed mutants of CODHMt. Mutational analysis of particular histidine residues and various other conserved residues of CODH from Moorella thermoacetica is discussed. Visual inspection of the crystal structure of CODHRr and CODHCh, along with sequence alignments, indicates that there may be separate pathways for proton and electron transfer during catalysis. Mutants of a proposed proton transfer pathway were characterized. Four semi-conserved histidine residues were individually mutated to alanine. Two (His116Mt and His122Mt) were essential to catalysis, while the other two (His113Mt and His119Mt) attenuated catalysis but were not essential. Significant activity was "rescued" by a double mutant where His116 was replaced by Ala and His was also introduced at position 115. Activity was also rescued in double mutants where His122 was replaced by Ala and His was simultaneously introduced at either position 121 or 123. Activity was also "rescued" by replacing His with Cys at position 116. Mutation of conserved Lys587 near the C-cluster attenuated activity but did not eliminate it. Activity was virtually abolished in a double mutant where Lys587 and His113 were both changed to Ala. Mutations of conserved Asn284 also attenuated activity. These effects suggest the presence of a network of amino acid residues responsible for proton transfer rather than a single linear pathway.Item Kinetic and Friction Head Loss Impacts on Horizontal Water Supply and Aquifer Storage and Recovery Wells(2014-12-02) Blumenthal, BenjaminGroundwater wells can have extreme pressure buildup when injecting and extreme pressure drawdown when extracting. Greater wellbore contact with the aquifer minimizes pressure buildup and pressure drawdown. Aquifers are usually much more laterally extensive than vertically thick. Therefore, horizontal wells can be longer than vertical wells thus increasing aquifer contact and minimizing pressure issues. The length and therefore the effectiveness of horizontal wells are limited by two factors, either well construction or intra-wellbore head loss. Currently no analytical groundwater model rigorously accounts for intra-wellbore kinetic and friction head loss. We have developed a semi-analytical, intra-wellbore head loss model dynamically linked to an aquifer. This model is the first of its kind in the groundwater literature. We also derived several new boundary condition solutions that are rapidly convergent at all times. These new aquifer solutions do not require approximation or pressure pulse tracking. We verified our intra-wellbore head loss model against MODFLOW-CFP and found matches of three significant figures. We then completed 360 simulations to investigate intra-wellbore head loss. We found that only when aquifer drawdown was small will intra-wellbore head loss be relatively important. We found intra-wellbore head loss is relatively important only in extreme scenarios. We also found that kinetic head loss was greater than friction head loss if the well was less than 10m ? 100m long. To investigate well construction limitations, we developed an equation for the optimal slant rig entry angle, a drilling forces model, and a well construction cost model. We then collected well cost data and combined these models to make 60 well cost estimates. We found the relative cost of a horizontal well, compared to a vertical well, decreases with depth. We then used our aquifer model to investigate the benefits of horizontal wells. We found several parameters that increase the number of vertical wells replaced by a horizontal well. These parameters include less time since pumping began, nearby recharge boundaries, vertical fractures, lower permeability, higher specific storativity, and thinner aquifers. Comparing horizontal well benefit with cost, we found that horizontal wells may or may not be economically advantageous depending on site specific conditions.Item MHD GAMs and kinetic GAMs driven by energetic particles(2009-12) Zhou, Tianchun; Berk, H. L.In this dissertation, we investigate the n=0 Geodesic Acoustic Modes (GAM) in the framework of both magneto-hydrodynamics and kinetics. In MHD, the purpose is to understand the numerical results out of the CASTOR code (1). Effects of energetic particle are ignored. The leading perturbation is the density perturbation, which leads to a local GAM. The coupling of density perturbation to the magnetic perturbation, which is treated to be smaller, leads to global a GAM. We recover the numerical results from the CASTOR code and obtain and analytical solution to the radial eigen-mode equation though asymptotic matching. To understand recent experimental results on DIII-D (2) a kinetic theory is constructed in which magnetic perturbations are neglected and energetic ions are treated on the same footing as the thermal species based on drift kinetics. Not only do the energetic particles destabilize the local GAM induced by thermal species, but they are also crucial to establish the global GAM due to their large orbit shifts. Polarization of thermal ions is included. A mechanism for fast GAM excitation through NBI is proposed, based on our local kinetic GAM theory when there exists a loss boundary in pitch angle.