Oxidation and agglomeration resistance of thin gage dispersion strengthened alloys Final report

Measuring oxidation resistance of thin dispersion strengthened nickel-chromium alloys for aircraft application

Rheological study of structural transitions in triblock copolymers in a liquid crystal solvent

Rheological properties of triblock copolymers dissolved in a nematic liquid crystal (LC) solvent demonstrate that their microphase separated structure is heavily influenced by changes in LC order. Nematic gels were created by swelling a well-defined, high molecular weight ABA block copolymer with the small-molecule nematic LC solvent 4-pentyl-4-cyanobiphenyl (5CB). The B midblock is a side-group liquid crystal polymer (SGLCP) designed to be soluble in 5CB and the A endblocks are polystyrene, which is LC-phobic and microphase separates to produce a physically cross-linked, thermoreversible, macroscopic polymer network. At sufficiently low polymer concentration a plateau modulus in the nematic phase, characteristic of a gel, abruptly transitions to terminal behavior when the gel is heated into its isotropic phase. In more concentrated gels, endblock aggregates persist into the isotopic phase. Dramatic changes in network structure are observed over small temperature windows (as little as 1 °C) due to tccche rapidly changing LC order near the isotropization point. The discontinuous change in solvent quality produces an abrupt change in viscoelastic properties for three polymers having different pendant mesogenic groups and matched block lengths

Specific volumes of the Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 alloy in the liquid, glass, and crystalline states

The specific volumes of the Zr41.2Ti13.8CU12.5Ni10.0Be2.25 alloy as a function of temperature, T, are determined by employing an image digitizing technique and numerical calculation methods applied to the electrostatically levitated spherical alloy. The linear fitting of the volumes of the alloy in the liquid, V-l, glass, V-g, and crystalline V-c, states in the temperature ranges shown in parentheses are V-l(T) = 0.1583 + 8.877 x 10(-6)T(cm^(3)/g) (700-1300 K); V-g(T) = 0.1603 + 5.528 x 10^(-6)T (400-550 K); V-c(T) = 0.1583 + 6.211 x 10(-6)T(400-850 K). The average volume thermal expansion coefficients within the temperature ranges are determined to be 5.32, 3.39, and 3.83 x 10^(-5) (1/K) for the liquid, glass, and crystalline states, respectively

Nonlinear stochastic controllers for semiactive and regenerative structural systems, with guaranteed quadratic performance margins

In many applications of vibration control, the circumstances of the application impose constraints on the energy available for the actuation of control forces. Semiactive dampers (i.e., viscous dampers with controllable coefficients) constitute the simplest example of such actuation in structural control applications. Regenerative Force Actuation (RFA) networks are an extension of semiactive devices, in which mechanical energy is first converted to electrical energy, which is then dissipated in a controllable resistive network. A fairly general class of semiactive and regenerative systems can be characterized by a differential equation which is bilinear (i.e., linear in state, linear in control input, but nonlinear in both). This paper presents a general approach to bilinear feedback control system design for semiactive and regenerative systems, which is analytically guaranteed to out-perform optimal linear viscous damping in stationary stochastic response, under the familiar Quadratic Gaussian performance measure. The design for full-state feedback and for the more practical case of noise-corrupted and incomplete measurements (i.e., output feedback) are separately discussed. Variants of the theory are shown to exist for other quadratic performance measures, including risk-sensitive and multi-objective frameworks. An illustrative application to civil engineering is presented

Patterning High Surface Area Silica with Lysozyme: Adsorption Kinetics, Fluorescence Quenching, and Protein Readsorption Studies To Evaluate the Templated Surface

A method was developed for using an inexpensive and widely available protein, hen egg white lysozyme, as a patterning agent for commercial high surface area silicas. The basic patterning methodology involved spontaneous adsorption of the protein from aqueous solution, alkylation of the uncovered surface with an alkylsiloxane, and protein desorption in a slightly alkaline solution of morpholine. Adsorption kinetic studies using Bradford assays assisted in determining protein deposition conditions. These studies were generally consistent with results on more planar silica surfaces and indicated that the protein quickly and strongly adsorbs along its long axis at low surface coverages. A modified fluorescence resonance energy transfer (FRET) technique was developed and employed to evaluate protein spacing. This technique showed that the proteins are well dispersed at low coverages. Readsorption experiments show that the templated regions are robust, retaining the size and shape of the original protein templates

Detachable force sensor for an ultrasound probe to improve rotator cuff injury diagnosis

Rotator cuff disease, common in elderly persons and athletes, is resultant of repetitive use of shoulder muscles or sudden impact to the area. The spectrum of injury ranges from tendonitis to a complete tear of the rotator cuff tendon which results in a myriad of treatments. Even though ultrasound is one of the most frequently used imaging techniques to diagnose this disease, it lacks contextual information and consistency needed for an accurate treatment plan. We are creating an ultrasound probe attachment using pressure sensing pads to measure force applied during imaging. Using our pads, we measured the change in resistance across the pad which can be used with pre-existing ultrasound imaging data to calculate the Young\u27s Modulus of the tissue. We hope this will provide more consistency in characterizing the rotator cuff. For the clinician, having this additional information may help to determine the extent of the injury and be beneficial in determining the appropriate treatment

Support for Redistribution in Western Europe: Assessing the role of religion

Previous sociological studies have paid little attention to religion as a central determinant of individual preferences for redistribution. In this article we argue that religious individuals, living in increasingly secular societies, differ in political preferences from their secular counterparts. Based on the theory of religious cleavages, we expect that religious individuals will oppose income redistribution by the state. Furthermore, in contexts where the polarization between religious and secular individuals is large, preferences for redistribution will be lower. In the empirical analysis we test our predictions in a multilevel framework, using data from the European Social Survey 2002–2006 for 16 Western European countries. After controlling for a wide range of individual socio-economic factors and for welfare-state policies, religion plays and important explanatory role. We find that both Catholics and Protestants strongly oppose income redistribution by the state. The cleavage between religious and secular individuals is far more important than the difference between denominations. Using a refined measure of religious polarization, we also find that in more polarized context the overall level of support for redistribution is lower

Pull From the Knee: Proper Technique and Application

The pull from the knee is a weightlifting movement derivative that can be used in the teaching progression of the clean and snatch exercises. This exercise emphasizes positional strength during the transition phase and the triple extension of the hip, knee, and ankle joints that is characteristic of weightlifting movements