A hybrid bearing designed for use in a next generation turbo-pump is evaluated for the performance of initial lift-off, referred to as start-transient. The radial test rig features a high-speed spindle motor capable of 20,000 rpm that drives a 718 Inconel rotor attached via a high-speed coupling. The drive end is supported by ceramic ball bearings, while the hybrid bearing supports the opposite end. A magnetic bearing delivers the applied loading along the mid-span of the rotor. Many parameters, including ramp rate [rpm/s] (drive torque), supply pressure at 15,000 rpm, magnitude of the applied load, and load orientation, are varied to simulate different start-transient scenarios. The data are recorded in .dat files for future evaluation of transient predictions. Analysis of the data includes an evaluation of hydrodynamic and hydrostatic liftoff, an assessment of rub from passing through a lightly damped critical speed, and observation of pneumatic hammer instability. Hydrodynamic lift-off occurs when the hydrodynamic pressure, resulting from the relative motion of two surfaces, overcomes the forces acting on the rotor; no indication of hydrodynamic lift-off is provided. Hydrostatic lift-off results from the external supply pressure (which for this test rig is speed dependent) overcoming the forces acting on the rotor as determined from rotor centerline plots. With 0.263 bar applied unit load in the vertical direction, hydrostatic lift-off occurs at 0 rpm and 2.08 bar supply pressure. With a much higher load of 1.53 bar, hydrostatic lift-off is at 12,337 rpm and 10.7 bar supply pressure. The required supply pressure for hydrostatic lift-off is approximately a linear function of the applied unit load. In a turbopump, hydrostatic lift-off depends on the speed because the supply pressure is proportional to the speed squared. With the load in the horizontal direction, hydrostatic lift-off occurs at lower speeds and pressures. The ramp rate did not affect the required supply pressure for hydrostatic lift-off. A lower supply pressure at 15,000 rpm lowered the required supply pressure for hydrostatic liftoff as well as the natural frequencies creating a rub. The hydrostatic lift-off speed should be minimized to avoid damage to the rotor/bearing surfaces due to contact.

Organic – ordered mesoporous silica (OMS) hybrid materials have attracted great interest due to their potential applications for gas separations, and heterogeneous catalysis. Amine-functionalized OMS materials are active in a variety of base-catalyzed reactions. The key to successfully achieving the desired reactivity is the ability to rationally tether the targeted organic functionality onto the OMS surface. Understanding the organic-inorganic interface is crucial for rational design of heterogeneous catalysts, because the local structure and molecule dynamics are paramount in determining the reactivity of the organic groups attached to the OMS surface. This dissertation focuses on three goals that will lead to a description of the organic-OMS interface and designing hybrid catalysts: 1) Determining the dynamics of organic groups attached to the OMS surface, 2) Catalytic testing to understand how the local structure and dynamics of the organic moiety influence the catalytic properties of organic-OMS catalysts, 3) Designing more active hybrid catalysts by introducing higher loadings of organic group using dendrimer structures. Solid-state NMR is uniquely suited for quantifying dynamics in the milli- to nano-second time scale. Deuterium (2H) NMR is a powerful tool to obtain detailed information about the dynamics or organic molecules. In this study, several simple functional groups isotopically labeled with deuterium have been attached to MCM-41 and SBA-15. The spectra display different molecular motions for different organic moieties. The results have indicated that the interactions between the functional groups and silanol groups on the surface influence the mobility of the organic fragments. Also, the porosity of the solid supports effects dynamics via confinement. The catalytic properties of simple amine groups attached to MCM-41, containing primary, secondary, and tertiary amines have been compared in the Nitroaldol (Henry) reaction. The effects of amine identity, structure, loading, presence of surface silanols, and the substrate topology on the catalytic properties have been investigated. The dramatic decrease of the activity of amine-functionalized MCM-41 by capping the residual silanol groups with hexamethyldisilazane was ascribed to the decrease of the interactions of hydrogen bonding between the amine functional groups and surface silanols. The result was consistent with the changes of the molecular motions shown by 2H NMR measurements. Fabricating OMS hybrid materials with high densities of organic functional groups leads to challenges in realizing uniform, catalytically active sites. Our group has immobilized melamine-based dendrimers on the surfaces of amine-functionalized SBA-15 materials by iterative synthesis procedures. The current studies in this dissertation mainly describe the catalytic properties of these dendrimers on SBA-15 and MCM-41 in the Nitroaldol (Henry) reaction, the transesterification reaction of triglycerides and methanol to synthesize methyl esters, and the cross aldol reaction between acetone and 5-hydroxymethylfurfural. The results indicate that the OMS-dendron materials have potential as solid base catalysts for a range of reactions.

There are two important techniques, automatic repeat request (ARQ) and forward error control (FEC), in error control systems. ARQ uses redundancy for detecting errors. While an error is detected in a transmitted code word, the receiver requests the transmitter to re-transmit the corrupted code word and the transmitted code word with detected error is discarded. However, the transmitted code word with detected error still contains a lot of information. ARQ schemes require a feedback channel. FEC relies on the controlled use of redundancy in the transmitted code word to detect and correct errors. Whether the decoding of the received code word is successful, no further processing is performed at the receiver. Therefore, FEC requires only a one-way link between the transmitter and receiver. In error control systems, a powerful FEC, turbo coding, was first proposed in 1993. Its performance was investigated by simulation to be close to the Shannon limit. Hybrid ARQ (HARQ) systems after properly combining the ARQ techniques and FEC techniques, can be classified into type-I, type-II and type-III, and its performance can be elevated far more than ARQ systems. HARQ adopts the FEC methods to detect and correct the error patterns caused in the process of transmission. While errors are detected in the demodulated signals at receiver and fail to be corrected, the receiver will activate ARQ mechanism to request the transmitter to retransmit related information to achieve an error-free transmission. In this thesis, a feasible type-II hybrid ARQ algorithm is proposed. Performance of the proposed algorithm is evaluated and analyzed by computer simulations. Compared with the traditional HARQ algorithms, the proposed algorithm can offer better performance in delay time and number of retransmissions with approximate throughput.

We had demonstrated that, by controlling and changing the temperature, reaction time and washing agents, the morphology and powder size of CuInSe2 can be altered considerably. CuInSe2 was synthesized by a solvothermal route as described by Y. Qian et al. By synthesizing nanorods, we can control the distance which the electrons are transported in hybrid solar cell with conjugated polymers. With the tuning of the band gap by controlling the nanorod length, we can increase the opportunity of orbits overlap between the CuInSe2 material and the PBO polymer matrix.. The synthetic temperature 1800C and reaction time 48 hrs are the best condition in our experiment. By using D.I water and ethanol as washing agents, we can find different morphology of spherical and nanowire. However, we fabricate hybrid solar cell by using these CuInSe2 powders in PBO conjugated polymers. By preparing hybrid solution in different concentration and controlling spin coating rate, we fabricate solar cells device successfully. From the I-V characteristics, we can get noticeable characteristics of diode. Then, we calculate the fill factor (F.F.) with the open-circuit voltage¡]Voc¡^and short-circuit current¡]Isc¡^

Tumor Susceptibility Gene, TSG101, has been identified as a tumor susceptibility gene with multiple functions. TSG101 encodes a 46 kDa protein composed of 390 amino acids. As previous studies reported, TSG101 participates in cell-cycle control, membrane proteins¡¦ trafficking, and transcriptional regulation. To identify the proteins that mediated function involved TSG101, we perform yeast two-hybrid cDNA library screening to search for TSG101-interacting proteins. A construct pAS2-1-TSG101 was used as a bait to screen a human testis cDNA library. This screening selected 68 TSG101 interacting clones, including 17 known proteins. These proteins were functionally classified as participating in cell-cycle alteration, protein sorting, transcriptional regulation, modification, signal transduction and other functions. Our results provide the evidences which not only confirm the results of previous studies, but also provide further information related to TSG101 biological functions worth intensive study. Among these clones, we choose KLIP1 gene, which encodes a transcription factor, for further study to elucidate the functional role of TSG101 in nucleus. In vitro GST pull-down assay and in vivo co-immunoprecipitation assay were performed using GST-KLIP1 and HA-tagged KLIP1, respectively, have demonstrated that TSG101 and KLIP1 indeed interact with each other within mammalian cells. Detailed biological function mediated through this TSG101 and KLIP1 interaction awaits further investigation.

A numerical method for the simulation of compressible turbulent flows is presented. This method includes a novel hybrid grid generation for airfoil cascades and an unstructured mesh flow solver. The mesh tool incorporates a mapping technique and a grid smoothing method. The mapping technique is used to build an initial volume mesh and the grid smoothing method is used to improve the quality of the initial mesh. The grid smoothing is based on the optimization of mesh-quality parameters. The further improvement of the smoothed mesh is achieved by an edge-swapping and node-insertion technique. The unstructured flow solver is developed for a hybrid grid. This flow solver uses a rotational frame of reference. The convective and viscous fluxes are numerically solved by an upwind scheme and an averaged nodal gradient. A higher-order spatial accuracy is achieved by a piece-wise linear reconstruction. An explicit multi-stage method is employed for integration in time. The Menter’s k −τ model is implemented to simulate the turbulence effects. The flow solver is validated against the analytical and experimental results. A parametric study is performed for a high speed centrifugal compressor.

The US hybrid striped bass (Morone chrysops x M. saxatilis) industry has been negatively impacted by infectious diseases because there are very few approved drugs and vaccines. Therefore, a series of experiments was conducted to explore the potential use of various dietary supplements including autolyzed brewers yeast, the commercial prebiotic GroBiotic®, oligonucleotides and levamisole for improvement of hybrid striped bass growth, immunity and resistance to disease caused by various pathogenic bacteria. In two trials with brewers yeast, fish fed diets supplemented with yeast at 2% generally showed enhanced weight gain and feed efficiency compared with those fed a basal diet. Brewers yeast also positively influenced resistance to S. iniae infection. In addition, results of immune response assays demonstrated that brewers yeast can be administered for relatively long periods without causing immunosuppression. GroBiotic® (Grobiotic) also resulted in significantly enhanced weight gain, innate immune responses and resistance of juvenile hybrid striped bass to S. iniae infection. An additional experiment with sub-adult fish showed significantly reduced mortality of fish fed a diet supplemented with GroBiotic® at 2% when subjected to an in-situ Mycobacterium marinum challenge. This is the first report of positive effects from dietary prebiotics for fish health management, although many fundamental questions should be pursued further. Dietary supplementation of a commercial oligonucleotide product (Ascogen P®) at 0.5% of the diet was shown to enhance resistance of hybrid striped bass against S. iniae infection and increased their neutrophil oxidative radical production. However, the effect on growth was marginal. Dietary levamisole supplementation at a low level (100 mg/kg) enhanced the growth and feed efficiency of juvenile hybrid striped bass. However, an elevated dosage (1000 mg/kg diet) strongly suppressed growth, feed intake and feed efficiency. Hypothesized beneficial influences, including antibody production and resistance to S. iniae and A. hydrophila were not substantiated. Although dietary levamisole increased fish macrophage respiratory burst, an in vitro study failed to show a direct effect on cultured macrophages. This suite of studies demonstrated the potential use of some dietary supplements to enhance hybrid striped bass production. Thus, immunonutrition represents a valuable strategy to apply in aquaculture.

This paper proposes a hybrid routing protocol based on the k-hop clustering structure for MANETs. The source sends packets to the destination directly if it is in the source¡¦s neighbor table; otherwise the source reactively sends the route request packet (RREQ) to trigger the routing process. Instead of adopting the nodes that forwards the RREQ as the route between the source and destination, the route reply packet (RREP) is broadcasted via the nodes in the clusters that the RREQ has ever passed to find the route. The route constructed in this way can avoid the clusterheads always being in the transmission route and collapsing due to overloading. In comparison with the Cluster Based Routing Protocol (CBRP), the proposed protocol can distribute the communication workload from the clusterheads to member nodes. Simulation results demonstrate that the proposed protocol has better packet delivery ratio and end-to-end delay time than that of CBRP.

The goal of this thesis was to improve the energy efficiency of building ventilation systems by exploring new methods of applying natural ventilation concepts. Strictly natural systems have limitations in which climates they can function or can provide optimal performance; these limitations lead to the use of mechanical or hybrid ventilation. This study looked at methods of combining the operation of the systems, such that the natural components improve the efficiency of the mechanical system.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xi, 100 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 69-72).