13,359 research outputs found
Fluid phase analyzer Patent
Mixed liquid and vapor phase analyzer design with thermocouples for relative heat transfer measuremen
Flow control valve
A flow control valve for high temperature fluids is disclosed. The valve is characterized by an all-metal flow control unit including a tubular conduit, terminating in a valve seat, a throttling cone having an internal, truncated conical surface coaxially related to the valve seat and supported for axial motion relative to the seat, and an axially reciprocable, flow-control plug supported in coaxial relation with the cone. The plug is provided with a truncated conical surface configured to be mated with the surface of the throttling cone for regulating a flow of fluid established through the unit and a curved shut-off surface
Condenser heat rejection systems monthly progress report, jan. 1962
Fabrication and testing of large diameter multiple tube jet condense
Corrosion of niobium-1 percent zirconium alloy and yttria by lithium at high flow velocities
Lithium corrosion of niobium zirconium alloys and yttrium oxides at high flow velocitie
Liquid metal magnetohydrodynamics (LMMHD) technology transfer feasibility study. Volume 1: Summary
The potential application of liquid metal magnetohydrodynamics (LMMHD) to central station utility power generation through the period to 1990 is examined. Included are: (1) a description of LMMHD and a review of its development status, (2) LMMHD preliminary design for application to central station utility power generation, (3) evaluation of LMMHD in comparison with conventional and other advanced power generation systems and (4) a technology development plan. One of the major conclusions found is that the most economic and technically feasible application of LMMHD is a topping cycle to a steam plant, taking advantage of high temperatures available but not usable by the steam cycle
Liquid metal magnetohydrodynamics (LMMHD) technology transfer feasibility study. Volume 2: Appendixes
For abstract, see N74-13466
Microstructure Controlled Shear Band Pattern Formation and Enhanced Plasticity of Bulk Metallic Glasses Containing in situ Formed Ductile Phase Dendrite Dispersions
Results are presented for a ductile metal reinforced bulk metallic glass matrix composite based on glass forming compositions in the Zr-Ti-Cu-Ni-Be system. Primary dendrite growth and solute partitioning in the molten state yields a microstructure consisting of a ductile crystalline Ti-Zr-Nb β phase, with bcc structure, in a Zr-Ti-Nb-Cu-Ni-Be bulk metallic glass matrix. Under unconstrained mechanical loading organized shear band patterns develop throughout the sample. This results in a dramatic increase in the plastic strain to failure, impact resistance, and toughness of the metallic glass
Large supercooled liquid region and phase separation in the Zr–Ti–Ni–Cu–Be bulk metallic glasses
Results of calorimetric, differential thermal analysis, and structural measurements are presented for a series of bulk metallic glass forming compositions in the Zr-Ti-Cu-Ni-Be alloy system. The calorimetric data for five alloys, prepared along the tie line between phase separating and nonphase separating compositions, show that the transition from phase separating to nonphase separating behavior is smooth. The bulk glasses near the center of the tie line exhibit large supercooled liquid regions: Delta T approximate to 135 K, the largest known for a bulk metallic glass
Testing Models of Counselor Development With a Measure of Counseling Self-Efficacy
Models of counselor development have become very popular, but empirical research has found differences primarily between beginning graduate students and doctoral interns, in the research described here, a counseling self-efficacy instrument was developed and was used to test hypotheses based on self-efficacy theory and models of counselor development, both of which would make similar predictions about increases in counseling self-efficacy resulting from clinical training and experience. The findings include strong reliability and validity evidence for the instrument and several significantly different groups of participants that correspond roughly to the groups hypothesized in stage models of counselor development
Multiquantal Glutamate Release from Rod Photoreceptors
Neurons communicate via Ca2+-dependent release of neurotransmitters packaged into vesicles (quanta). Some CNS neurons, especially sensory synapses, can release multiple vesicles at a time, increasing information transmission and overcoming the unreliability of a stochastic process. Ribbon-bearing neurons, including retinal photoreceptors, face the challenge of encoding sensory receptor potentials into an ever-changing train of vesicle release events. We studied release of glutamate using voltage clamp to measure anion currents activated during glutamate reuptake into presynaptic terminals (IA(glu)) of salamander and mouse rods, finding that each employ distinct mechanisms for multiquantal release. In amphibian rods, we found that 1/3 of the spontaneous IA(glu) fusion events involve synchronous fusion of multiple vesicles. By varying intracellular buffering to localize Ca2+-dependent events, we found that multiquantal release occurs near Ca2+ sources. In photoreceptors, Ca2+ influx occurs just below synaptic ribbons. Vesicles house SNARE machinery so we hypothesized that vesicles on the ribbon undergo homotypic fusion prior to exocytosis. Destruction of ribbons and disruption of the SNARE-protein syntaxin3B prevented spontaneous multiquantal release, suggesting that salamander rods are capable of multivesicular release due to homotypic fusion of vesicles along ribbons. In mouse rods, spontaneous release at −70 mV involved the stochastic fusion of single vesicles. With depolarization, glutamate release increased linearly with voltage-gated Ca2+ currents. As the membrane approached the resting potential in darkness of −40 mV, rods began to release glutamate in multivesicular bursts of 17±7 vesicles every 2801±598 ms. Release evoked by brief depolarizations and bursts both involved the same pool of ribbon-associated vesicles with fusion regulated by the vesicular Ca2+ sensor synaptotagmin-1. A second, slower component of release controlled by synaptotagmin-7 is also present in rods but not cones. We hypothesized a v role for coordinated bursts of release in transmitting single photon signals. The rate of bursting was responsive to small voltage changes of 1.0-3.5 mV and the voltage waveform that triggered bursts most effectively was similar to single photon responses. We propose that multiquantal bursts contribute to mechanisms that filter out small noisy events to improve reliable detection of single photons by the retina
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