Local sensitivity analysis for the heat flux-temperature integral relationship in the half-space

This paper presents insight into the heat flux-temperature (q″ ? T) integral relationship based on constant thermophysical properties. This relationship is often used in one-dimensional, transient heat transfer studies involving null-point calorimetry and heat flux investigations. This study focuses on a short transient studies where energy has not fully penetrated the body as the result of an imposed surface heating condition. A full nonlinear heat transfer model is developed involving a half-space planar region. Temperature results are then introduced into the constant property integral relationship and a newly derived Kirchoff integral relationship for retrieving the local heat flux. Good agreement is observed between the fully nonlinear results and locally linearized system. Additionally, a sensitivity study is presented which involves perturbing the average thermophysical properties of thermal conductivity and heat capacity.     

Heavy fragment production cross sections from 1.05 GeV/nucleon 56Fe in C, Al, Cu, Pb, and CH2 targets

We have obtained charge-changing cross sections and partial cross sections for fragmentation of 1.05 GeV/nucleon Fe projectiles incident on H, C, Al, Cu, and Pb nuclei. The energy region covered by this experiment is critical for an understanding of galactic cosmic ray propagation and space radiation biophysics. Surviving primary beam particles and fragments with charges from 12 to 25 produced within a forward cone of half-angle 61 mrad were detected using a silicon detector telescope to identify their charge and the cross sections were calculated after correction of the measured yields for finite target thickness effects. The cross sections are compared to model calculations and to previous measurements. Cross sections for the production of fragments with even-numbered nuclear charges are seen to be enhanced in almost all cases.     

Spectral characterization of fiber gratings with high resolution

We demonstrate a high-resolution technique to measure the optical magnitude and phase responses of fiber gratings. The technique employs single-sideband modulation of an optical source and has spectral resolution in the hertz regime. The technique is demonstrated by measurement of the phase ripples of unapodized and apodized chirped gratings as well as the transmission spectrum of a pi-phase-shifted grating. Although it is demonstrated on fiber gratings, the technique is applicable to any optical device.     

Theoretical development of a new surface heat flux calibration method for thin-film resistive temperature gauges and co-axial thermocouples

This paper presents a theoretically developed and computationally demonstrated surface heat flux calibration method applicable to thin-film resistive temperature gauges and co-axial thermocouples. For this study, the physical situation of interest involves hypersonic shock-tunnel studies. For experiments instrumented with these gauges, constant thermophysical properties are assumed since small temperature variations normally occur in the short-duration run times. Extraction of the net surface heat flux is acquired by resolving a newly formulated first-kind Volterra integral equation that contains calibration data. The proposed calibration method is based on an inverse approach which contrasts system identification methods. Several key advantages to this approach are discussed and demonstrated in the context of these gauges. Advantages of the proposed approach include (a) only one unknown “regularization” parameter is required; (b) estimation of the optimal regularization parameter is systematically and theoretically developed and demonstrated through the energy residuals, (c) computational coding is minimal and computer run times are short, and (d) results indicate robustness, stability and accuracy in the methodology. This calibration formulation and its subsequent regularized numerical method do not explicitly require the thermal effusivity, $\sqrt{\rho C k}$ owing to its input–output based derivation.     

An alpha-helical peptidomimetic inhibitor of the HIV-1 Rev-RRE interaction

The interaction between the HIV-1 Rev protein and the Rev-Responsive Element (RRE) RNA is an attractive target for anti-viral therapy. We have designed alpha-helical peptidomimetics of Rev-like peptides using side chain-side chain macrolactam formation between positions i and i+4. One peptidomimetic having an appropriate location, orientation, and length of the macrolactam exhibited both significant helical character and specific RRE binding. This molecule displays 2-fold greater RNA specificity than the wild-type Rev peptide and more than 20-fold greater specificity than an uncyclized control peptide. Thus, specific, high affinity recognition of the RRE is feasible utilizing a small, relatively rigid peptidomimetic scaffold.