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Session B3: Replacement Turbine Design for Improved Fish Passage at Ice Harbor
No full textPresenting Author Bio: Dr. Jason Foust is employed by Voith Hydro, Inc. in York, Pennsylvania. After completing his graduate studies in Experimental Fluid mechanics, he began working as a hydraulic engineer. Since that time, Dr. Foust has focused on design and testing for turbine rehabilitation projects. In addition to his design responsibilities, he has also been involved in the development of environmentally friendly hydro turbines in regard to turbine aeration and fish passage.Abstract: In the summer of 2014, an extensive hydraulic development was completed for replacement fixed and adjustable blade turbines for the US Army Corps of Engineers’ (USACE) Ice Harbor Lock and Dam. During the hydraulic design phase, fish passage considerations made up the primary evaluation criteria, including minimum pressures, shear, flow quality, and blade strike. Expected fish passage characteristics for each set of proposed geometries were evaluated using both Computational Fluid Dynamic (CFD) calculations and physical model testing. Turbine performance characteristics, such as power and efficiency, were also considered as secondary evaluation criteria. For both machine types, several design and test loops were completed. At the end of each iteration, the design team, consisting of engineers and biologists from the USACE, Voith Hydro, and the National Marine Fisheries Service (NMFS), evaluated the results and identified aspects of the fish passage environment that could be improved. As the design process neared completion, final improvements to the overall fish passage environment involved making compromises between the individual design criteria. The current paper presents computational and model test results to illustrate the detailed design and evaluation process, including the trade-offs that were made leading up to the selection of the final prototype fixed blade turbine geometry. Comparison of the fish passage evaluations for the fixed blade solution with those of the existing Ice Harbor Kaplan geometry shows significant potential for fish passage improvement
Optimal guidance and control of heterogeneous swarms for in-orbit self-assembly of large space structures: Algorithms and experiments
No full textThis Dissertation was approved for publication on 2019-07-12 at 14:10.DSpace SAF Submission Ingestion Package generated from Vireo submission #14288 on 2019-11-26 at 12:53:26Satellite design has been harshly constrained by surviving entry into space though the majority of the satellite's lifetime exists in much calmer conditions. Significant study has recently gone into assembling satellites and space structures in-orbit. Several methods have been proposed involving an assembler robot or astronaut which puts the parts together, but in the interest of saving resources we believe that it is advantageous to make this process autonomous and robust by leveraging existing optimal guidance and control schemes for a self-assembling swarm. This approach avoids single-point failures, requires significantly less ground support, provides increased reliability due to redundancy, increased flexibility, the ability to reconfigure for future missions, and the ability to self-repair. Since the satellites required could be mass-produced from a small set of different component types, the benefit from economy of scale would reduce the overall mission cost when compared to monolithic satellites. This dissertation details an optimal guidance and control scheme to enable in-orbit self-assembly of a large structure from a heterogeneous swarm of satellites. In the proposed scheme, the component satellites for the heterogeneous swarm are chosen to promote flexibility in final shape inspired by crystal structures and Islamic tile art. After the ideal fundamental building blocks are selected, basic nanosatellite-class satellite designs are presented to enable accurate attitude control simulations. The Swarm Orbital Construction Algorithm (SOCA) is a guidance and control algorithm that allows for the limited type heterogeneity and docking ability required for in-orbit assembly. The algorithm was tested in a simulated perturbed 6-DOF spacecraft dynamic environment for planar and out-of-plane final structures. The algorithm is then experimentally validated coarsely on omnidirectional wheeled robots and precisely on-board the M-STAR robots in the precision flat floor facility in the Caltech Aerospace Robotics and Control lab, the largest of its kind at any university.
In support of this effort, a better way of handling nonlinear dynamics constraints within sequential convex programs was developed. SCP is a useful tool in obtaining real-time solutions to direct optimal control, but it is unable to adequately model nonlinear dynamics due to the linearization and discretization required. As nonlinear program solvers are not yet functioning in real-time, a tool is needed to bridge the gap between satisfying the nonlinear dynamics and completing execution fast enough to be useful. Two methods are proposed, sequential convex programming with nonlinear dynamics correction (SCPn) and modified SCPn (M-SCPn), which mixes SCP and SCPn to reduce runtime and improve algorithmic robustness. Both methods are proven to generate optimal state and control trajectories that satisfy the nonlinear dynamics. Simulations are presented to validate the efficacy of the methods as compared to SCP.
In addition, several autonomous rendezvous and docking (AR&D) technologies were studied because in-orbit self-assembly requires repeated, reliable autonomous docking to ensure success. Docking small satellites in space is a high-risk operation due to the uncertainty in relative position and orientation and the lack of mature docking technologies. This is particularly true for missions that involve multiple docking and undocking procedures like swarm-based construction and reconfiguration. A tether-based docking system was evaluated in simulation as compared to traditional propulsive methods. The tether-based method provides a way to reduce the risk of the dock, since the docking maneuver is performed with a much smaller satellite and the reeling maneuver can be done gently. Tether-based methods still require some actuation on the docking end of the tether, and propulsion on such small systems is inexact. An electromagnetic docking system was investigated to address these issues. Designed with reconfigurable self-assembly in mind, the gripping mechanism is androgynous, able to dock at a variety of relative orientations, and tolerant of small misalignments. The electromagnetic system can be used either on the end of a tether or on the main spacecraft itself since the electromagnet is well controlled and the measurement of the ambient electromagnetic field can be used as to improve the intersatellite distance estimate enough to reduce the risk of docking to the main spacecraft. The performance of this system was validated experimentally on-board the M-STARs. The performance of the electromagnetic docking system on-board the simulators is then compared against a propulsive docking system tested in the same way. Overall, this dissertation provides optimal guidance and control algorithms for nonlinear systems to enable in-orbit self-assembly of heterogeneous swarms.Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2019-11-26 without embargo termsThe student, Rebecca Foust, accepted the attached license on 2019-07-11 at 22:49.The student, Rebecca Foust, submitted this Dissertation for approval on 2019-07-11 at 22:54.Made available in DSpace on 2019-11-26T20:35:07Z (GMT). No. of bitstreams: 2
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Previous issue date: 2019-07-1
Processing lignocellulosic by-product streams using organic acids
No full textHet doel van dit proefschrift is om de voorbehandeling van lignocelluloseachtige grondstoffen met organische zuren te bestuderen. Meer specifiek gesteld, richt dit onderzoek zich op de invloed van maleïnezuur en fumaarzuur op de suikerafbraak tijdens de voorbehandeling, en op de prestatie van deze zuren in de voorbehandeling zelf, vergeleken met zwavelzuur. De optimalisatie van de voorbehandeling met maleïnezuur houdt niet alleen in het maximaliseren van de suikeropbrengst en de gerelateerde baten, maar houdt ook rekening met nadelige kanten van de voorbehandeling die hogere kosten met zich meebrengen. Als laatste richt dit onderzoek zich op mogelijkheden om de toepassing van maleïnezuur uit te breiden naar andere, eiwithoudende lignocelluloseachtige grondstoffen. Omdat tarwe de meest verbouwde graansoort is in de Europese Unie, is tarwestro gekozen als grondstof voor het werk over voorbehandeling van lignocellulose in dit proefschrift. Voor het werk over eiwithoudende lignocelluloseachtige grondstoffen is gekozen voor het bijproduct van biodieselproductie uit oliezaden van Jatropha curcas; de ontoliede perskoek
Application to Charity School Kendal
No full textJacob Bolmer, the guardian of Solomon Foust, age 11, applies to the school for admission; both parents are living but unable to care for the child. 7.75" x 7.25
ORNL Mock-up tests of Inside Launch Pellet Injection on JET and LHD
No full textIn experiments on ASDEX-Upgrade and DIII-D tokamaks, the injection of D2 pellets from the magnetic high-field side of the plasma resulted in deeper pellet penetration and improved fueling efficiency. Based on those successful experiments, fusion researchers at the Joint European Torus and the Large Helical Device decided to implement inside launch pellet injection. These injection schemes require the use of curved guide tubes to route the pellets from the acceleration devices to the inside launch locations, and the pellets are subjected to stresses from centrifugal and impact forces in traversing the tubes. Before the installations on the large experimental fusion devices, mock-ups of the guide tubes were constructed and tested at the Oak Ridge National Laboratory to determine the pellet speed limit for reliable operation without pellet fracturing. In laboratory testing of the mock-ups, it was found that the pellet speed had to be limited to a few hundreds of meters per second for intact pellets. In this paper, the test equipment and experimental results are described
Significación y agencia en la experiencia del desgaste laboral
No full textCon un enfoque interdisciplinario, esta investigación aborda cómo las personas trabajadoras experimentan y significan el desgaste laboral, y hace énfasis en el ejercicio de su agencia al lidiar con él, es decir, en las prácticas que las personas llevan a cabo. Se parte del conocimiento recabado históricamente sobre el burnout, un concepto ampliamente estudiado clínicamente y muy valioso por sus aportes respecto al desgaste laboral, pero con algunas limitaciones desde el punto de vista sociocultural. Al entender en este trabajo al desgaste laboral como un fenómeno no personal o clínico, sino sistémico, se trabaja sobre él considerando los factores socioeconómicos, socioculturales y sociopolíticos en los que se desarrolla.
Tras analizar la información recabada en el trabajo de campo, tomando como unidad de análisis la reconstrucción de las experiencia laborales de diversos trabajadores en el Área Metropolitana de Guadalajara (AMG), se encuentra que estos se enfrentan a un sistema ante el cual responden principalmente, aunque no exclusivamente, mediante prácticas de resistencia física, social y emocional. También con base en este análisis, se proponen siete tipologías que presentan algunas maneras de ser trabajador en el AMG bajo un sistema predominantemente neoliberal.ITESO, A. C
How Do I Know? A Guide to the Selection of Personal Protective Equipment for Use in Responding to A Release of Chemical Warfare Agents
No full textAn incident involving chemical warfare agents requires a unique hazardous materials (HAZMAT) response. As with an HAZMAT event, federal regulations prescribe that responders must be protected from exposure to the chemical agents. But unlike other HAZMAT events, special considerations govern selection of personal protective equipment (PPE). PPE includes all clothing, respirators and monitoring devices used to respond to a chemical release. PPE can differ depending on whether responders are military or civilian personnel
The Paternalistic Eye: Senator Edwin Johnson and the U.S. Television Freeze
No full textThis study examines Senator Edwin Johnson’s involvement with the television freeze in the United States from 1948 to 1952. The Federal Communications Commission (FCC) instituted the freeze after postwar applications for television licenses far outstripped the capability of the VHF band to hold stations. During the freeze, Johnson, who was chair of the Senate Interstate and Foreign Commerce Committee, pressured the FCC to approve CBS’s non-compatible color system and to move broadcasting to the UHF band as a way to counteract RCA’s patent dominance in monochrome VHF broadcasting. To this end, the senator corresponded with the FCC chair, industry leaders, members of the media and the general public, and also set up his own committee to study the status of colour television technology. His position as commerce committee chair gave him a unique bully pulpit from which he was able to say and do things that FCC commissioners could not. Unencumbered by pressures from the industry or by congressional or executive oversight, Johnson was not afraid to make use of his status to take high-profile stands that were often at odds with the commission and, especially, powerful interests in the broadcast industry
“We Need This Television Just Like Any Other American Citizen”: The Battle Over Western TV Boosters, 1952-1961
No full textIn the wake of the Federal Communication Commission\u27s 1952 Sixth Report and Order, which established plans for a nationwide television system, it became clear that traditional station allocations could not provide service to many isolated mountainous regions. Thus enterprising tinkerers, appliance store operators, and others set up so-called booster stations to broadcast the signals of urban stations into isolated western towns. However, the FCC wanted the boosters shut down, contending that they threatened the overall television allocation plan and could potentially create dangerous interference. Booster operators and viewers who depended on them were able to enlist the help of Western congressmen and governors to plead their case. Ultimately, the FCC was forced several times to backtrack on booster prohibitions, ultimately approving their operation in 1960
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