Estuarine suspended aggregate dynamics and characteristics

The research presented in this study is motivated by the need to improve prediction of sediment transport in estuaries. A novel application of the Acoustic Doppler Velocimeter (ADV) in the lower Chesapeake Bay is shown to estimate in-situ particle fall velocity at a single point without affecting the ambient turbulence. Acoustic backscatter from the ADV proved to be the best estimator of mass concentrations due to its apparent insensitivity to the size or density of muddy aggregates. Fall velocities are estimated analytically from a balance of settling and diffusive flux gradients using two methods, one employing Reynolds concentration flux, and the other estimating eddy diffusivity using the von-Karman Prandtl equation. Single elevation estimates of fall velocity using the ADV to estimate Reynolds concentration flux produced the best estimates of fall velocity, which are on the order of 1 mm/s. A novel method is presented to measure TKE production using a profiling ADV instrument that has been contaminated by boat motion. The relative importance of physical processes that determine particle size distributions differs in three mid-Atlantic U.S.A. estuaries (York R., Elizabeth R., Chesapeake Bay) with different hydrodynamics and benthic characteristics as well as in different depth regimes within each estuary. Surface particle size dynamics in all of the estuaries are affected by irregular advection events. Middepth regions in the energetic estuaries are controlled tidally by the combined processes of TKE production decreasing particle size and differential settling increasing particle size. Middepth regions in the low energy estuary are controlled by irregular resuspension and trapping at the pycnocline of large low density particles. Bottom regions in all estuaries are most strongly influenced by resuspension, tidally in the energetic estuaries and irregularly in the low energy estuary. The interrelationships between metal concentrations, particle size, percent fixed solids (PFS), chlorophyll a, and molar Carbon to Nitrogen (C/N) ratios of suspended sediment are investigated in a heavily industrialized and polluted estuary, the Elizabeth R., VA. The relationship between PFS, C/N and aggregate size are also investigated in a relatively energetic, high concentration, and undisturbed estuary, the York. R., VA. Standard paradigms of contaminant concentration relationships with particle size and particle constituents were not supported in the low energy, low concentration suspended sediments of the Elizabeth R. (Abstract shortened by UMI.)

Embedded Sensors and Controls to Improve Component Performance and Reliability: Conceptual Design Report

The overall project objective is to demonstrate improved reliability and increased performance made possible by deeply embedding instrumentation and controls (I&C) in nuclear power plant components. The project is employing a highly instrumented canned rotor, magnetic bearing, fluoride salt pump as its I&C technology demonstration vehicle. The project s focus is not primarily on pump design, but instead is on methods to deeply embed I&C within a pump system. However, because the I&C is intimately part of the basic millisecond-by-millisecond functioning of the pump, the I&C design cannot proceed in isolation from the other aspects of the pump. The pump will not function if the characteristics of the I&C are not embedded within the design because the I&C enables performance of the basic function rather than merely monitoring quasi-stable performance. Traditionally, I&C has been incorporated in nuclear power plant (NPP) components after their design is nearly complete; adequate performance was obtained through over-design. This report describes the progress and status of the project and provides a conceptual design overview for the embedded I&C pump

Evaluation of Manufacturability of Embedded Sensors and Controls with Canned Rotor Pump System

This report documents the current status of fabrication and assembly planning for the magnetic bearing, canned rotor pump being used as a demonstration platform for deeply integrating I&C into nuclear power plant components. The report identifies material choices and fabrication sequences for all of the required parts and the issues that need to be either resolved or accommodated during the manufacturing process. Down selection between material options has not yet been performed. Potential suppliers for all of the necessary materials have also been identified. The assembly evaluation begins by logically subdividing the pump into modules, which are themselves decomposed into individual parts. Potential materials and fabrication processes for each part in turn are then evaluated. The evaluation process includes assessment of the environmental compatibility requirements and the tolerances available for the selected fabrication processes. A description of the pump power/control electronics is also provided. The report also includes exploded views of the modules that show the integration of the various parts into modules that are then assembled to form the pump. Emphasis has been placed on thermal environment compatibility and the part dimensional changes during heat-up. No insurmountable fabrication or assembly challenges have been identified

Evaluation of Manufacturability of Embedded Sensors and Controls with Canned Rotor Pump System

This report documents the current status of fabrication and assembly planning for the magnetic bearing, canned rotor pump being used as a demonstration platform for deeply integrating I&C into nuclear power plant components. The report identifies material choices and fabrication sequences for all of the required parts and the issues that need to be either resolved or accommodated during the manufacturing process. Down selection between material options has not yet been performed. Potential suppliers for all of the necessary materials have also been identified. The assembly evaluation begins by logically subdividing the pump into modules, which are themselves decomposed into individual parts. Potential materials and fabrication processes for each part in turn are then evaluated. The evaluation process includes assessment of the environmental compatibility requirements and the tolerances available for the selected fabrication processes. A description of the pump power/control electronics is also provided. The report also includes exploded views of the modules that show the integration of the various parts into modules that are then assembled to form the pump. Emphasis has been placed on thermal environment compatibility and the part dimensional changes during heat-up. No insurmountable fabrication or assembly challenges have been identified

Electrical Stimulation and Blood Flow Restriction Increase Wrist Extensor Cross-Sectional Area and Flow Meditated Dilatation Following Spinal Cord Injury

Purpose: To examine the effects of neuromuscular electrical stimulation (NMES) and blood flow restricted (BFR) exercise on wrist extensors cross-sectional area (CSA), torque and hand functions compared NMES only in individuals with incomplete tetraplegia. The acute effect of an acute bout of NMES with BFR on flow mediated dilation (FMD) was compared with BFR only. Method: Nine men completed 6 weeks twice weekly of bilateral NMES training of the wrist extensor muscles. The right forearm received NMES + BFR (30 % above the resting systolic blood pressure), while the left forearm received NMES only. The CSA of the extensor carpi radialis longus (ECRL) and extensor digitorum communis (EDC) muscles was measured on ultrasound images. Torque was measured isometrically and hand function with grasp and release test. Another eight men with SCI received NMES+BFR to the right forearm, while the left forearm received BFR only. Immediately, the FMD of the brachial artery was measured. Result: Following training, the ECRL CSA was 17 % greater in the NMES+BFR forearm (mean difference = 0.6 cm2, p = 0.003) compared with the NMES only. The NMES+BFR had a 15 % increase in ECRL CSA (mean increase = 0.58 cm2, p = 0.048). FMD increased (p = 0.05) in the exercise arm (12 ± 3 %) compared with the control arm (6.5 ± 6 %). Conclusion: NMES training with BFR is a strategy that can increase skeletal muscle size. NMES with and without BFR can improve wrist strength and hand function. The acute effects of NMES+BFR may suggest that an increase in FMD may partially contribute to skeletal muscle hypertrophy

Embedded Sensors and Controls to Improve Component Performance and Reliability: Conceptual Design Report

The overall project objective is to demonstrate improved reliability and increased performance made possible by deeply embedding instrumentation and controls (I&C) in nuclear power plant components. The project is employing a highly instrumented canned rotor, magnetic bearing, fluoride salt pump as its I&C technology demonstration vehicle. The project s focus is not primarily on pump design, but instead is on methods to deeply embed I&C within a pump system. However, because the I&C is intimately part of the basic millisecond-by-millisecond functioning of the pump, the I&C design cannot proceed in isolation from the other aspects of the pump. The pump will not function if the characteristics of the I&C are not embedded within the design because the I&C enables performance of the basic function rather than merely monitoring quasi-stable performance. Traditionally, I&C has been incorporated in nuclear power plant (NPP) components after their design is nearly complete; adequate performance was obtained through over-design. This report describes the progress and status of the project and provides a conceptual design overview for the embedded I&C pump

Dystrophin-deficient cardiomyocytes derived from human urine: New biologic reagents for drug discovery

The ability to extract somatic cells from a patient and reprogram them to pluripotency opens up new possibilities for personalized medicine. Induced pluripotent stem cells (iPSCs) have been employed to generate beating cardiomyocytes from a patient's skin or blood cells. Here, iPSC methods were used to generate cardiomyocytes starting from the urine of a patient with Duchenne muscular dystrophy (DMD). Urine was chosen as a starting material because it contains adult stem cells called urine-derived stem cells (USCs). USCs express the canonical reprogramming factors c-myc and klf4, and possess high telomerase activity. Pluripotency of urine-derived iPSC clones was confirmed by immunocytochemistry, RT-PCR and teratoma formation. Urine-derived iPSC clones generated from healthy volunteers and a DMD patient were differentiated into beating cardiomyocytes using a series of small molecules in monolayer culture. Results indicate that cardiomyocytes retain the DMD patient's dystrophin mutation. Physiological assays suggest that dystrophin-deficient cardiomyocytes possess phenotypic differences from normal cardiomyocytes. These results demonstrate the feasibility of generating cardiomyocytes from a urine sample and that urine-derived cardiomyocytes retain characteristic features that might be further exploited for mechanistic studies and drug discovery