Ultrasonic propagation in gases at high temperatures

Ultrasonic pulse method /1 to 3 MHz/ measures both sound speed and absorption in monatomic and polyatomic gases in a temperature range of 300 to 20000 degrees K at atmospheric pressure. Helium, nitrogen, oxygen, and argon are investigated

Ultrasonic temperature measuring device First quarterly progress report

Room temperature and elevated temperature preliminary ultrasonic measurements and capsule design, construction and testing - ultrasonic temperature measuring devic

Ultrasonic temperature measuring device Second quarterly progress report

Molybdenum wire, ultrasonic temperature measuring apparatu

High temperature measuring device

Ultrasonic pulse technique for measuring average gas temperature in nuclear rocket engine - sound propagation and environmental studie

Ultrasonic temperature measuring device Fourth quarterly progress report

Molybdenum and rhenium wire tested for use in ultrasonic temperature measurement devic

Ultrasonic measurement of core material temperature, phase 1

High temperature ultrasonic temperature measurements in nuclear rocket engine to determine feasibility of rhenium sensor as high temperature senso

Ultrasonic measurement of core material temperature, phase 2

Sheaths for pulse-echo ultrasonic temperature senso

Celiac vagus nerve stimulation recapitulates angiotensin II-induced splenic noradrenergic activation, driving egress of CD8 effector cells

Angiotensin II (AngII) is a peptide hormone that affects the cardiovascular system, not only through typical effects on the vasculature, kidneys, and heart, but also through less understood roles mediated by the brain and the immune system. Here, we address the hard-wired neural connections within the autonomic nervous system that modulate splenic immunity. Chronic AngII infusion triggers burst firing of the vagus nerve celiac efferent, an effect correlated with noradrenergic activation in the spleen and T cell egress. Bioelectronic stimulation of the celiac vagus nerve, in the absence of other challenges and independently from afferent signals to the brain, evokes the noradrenergic splenic pathway to promote release of a growth factor mediating neuroimmune crosstalk, placental growth factor (PlGF), and egress of CD8 effector T cells. Our findings also indicate that the neuroimmune interface mediated by PlGF and necessary for transducing the neural signal into an effective immune response is dependent on α-adrenergic receptor signaling

A Comparative Study of RANS, URANS and NLES Approaches for Flow Prediction in Pin Fin Array

Gas Turbine are nowadays largely used for aircraft propulsion and land-based power generation. The increased attention to environmental aspects has promoted research and development efforts both from manufacturers and research centres. The latest developments in turbinecooling technologies play a critical role in the attempt to increase the efficiency and the specific power of the most advanced designs. Pin fin arrays, in particular, are widely used in jet engine application because of their ability to enhance cooling by providing extended surfaces for conduction and convection. They are also known to be an effective means to create turbulence which naturally increases heat transfer. Pin fin turbulators are typically located inside the trailing edge of high pressure turbine blade where they also act as a structural support. The optimum shapes and spacing of such elements are usually determined experimentally, or more recently, by using Computational Fluid Dynamics (CFD). On the other hand, the comprehension of the real physics controlling the heat transfer enhancement process and the role played by the large scale vortical structures generated by the inserts, still represent a great challenge for fluid mechanic researchers. The problem has been intensively investigated by Ames et al. (2005) by means of an experimental campaign on pin fin matrix. From the numerical point of view, the principal bottleneck of the CFD approach as applied to this kind of massively unsteady flow is related to the high computational cost and to the reliability of the turbulence models. The main objective of this work is to offer a critical analysis of the performance of a cooling device consisting of a pin fin turbulators geometry, as predicted by different CFD models of various complexity, using similar computational technology to integrate the corresponding governing equations. Local velocity and turbulence distributions are presented and compared with available experimental data

Individual Differences in Need for Cognition and Decision-Making Competence among Leaders

When making decisions, people sometimes deviate from normative standards. While such deviations may appear to be alarmingly common, examining individual differences may reveal a more nuanced picture. Specifically, the personality factor of need for cognition (i.e., the extent to which people engage in and enjoy effortful cognitive activities; Cacioppo & Petty, 1982) may moderate decision makers’ susceptibility to bias, as could personality factors associated with being a leader. As part of a large-scale assessment of high-level leaders, participants completed a battery of decision-making competence and personality scales. Leaders who scored higher on need for cognition performed better on two of four components of a decision-making competence measure: framing and honoring sunk costs. In addition, the leader sample performed better than published controls. Thus, both individual differences in need for cognition and leadership experience moderate susceptibility to decision biases. Implications for broader theories of individual differences and bias are discussed