Sealing member and combination thereof and method of producing said sealing member Patent

Electrode sealing and insulation for fuel cells containing caustic liquid electrolytes using powdered plastic and meta

The turbulent heat flux in low Mach number flows with large density variations

A transport equation has been derived which is the difference between the volume- and mass-averaged velocities and is simply related to the turbulent heat flux phi sup h. Using this equation and an assumption analogous to the drift flux approximation of two-phase flow modeling, an algebraic closure relation for phi sup h that exibits fluxes due to directed transport proportional to -del anti p and due to gradient transport proportional to -del tau has been obtained

Technology needs for high-speed rotorcraft

A study to determine the technology development required for high-speed rotorcraft development was conducted. The study begins with an initial assessment of six concepts capable of flight at, or greater than 450 knots with helicopter-like hover efficiency (disk loading less than 50 pfs). These concepts were sized and evaluated based on measures of effectiveness and operational considerations. Additionally, an initial assessment of the impact of technology advances on the vehicles attributes was made. From these initial concepts a tilt wing and rotor/wing concepts were selected for further evaluation. A more detailed examination of conversion and technology trade studies were conducted on these two vehicles, each sized for a different mission

Space tug propulsion system failure mode, effects and criticality analysis

For purposes of the study, the propulsion system was considered as consisting of the following: (1) main engine system, (2) auxiliary propulsion system, (3) pneumatic system, (4) hydrogen feed, fill, drain and vent system, (5) oxygen feed, fill, drain and vent system, and (6) helium reentry purge system. Each component was critically examined to identify possible failure modes and the subsequent effect on mission success. Each space tug mission consists of three phases: launch to separation from shuttle, separation to redocking, and redocking to landing. The analysis considered the results of failure of a component during each phase of the mission. After the failure modes of each component were tabulated, those components whose failure would result in possible or certain loss of mission or inability to return the Tug to ground were identified as critical components and a criticality number determined for each. The criticality number of a component denotes the number of mission failures in one million missions due to the loss of that component. A total of 68 components were identified as critical with criticality numbers ranging from 1 to 2990

A Water Recovery System Evolved for Exploration

A new water recovery system designed towards fulfillment of NASA's Vision for Space Exploration is presented. This water recovery system is an evolution of the current state-of-the-art system. Through novel integration of proven technologies for air and water purification, this system promises to elevate existing technology to higher levels of optimization. The novel aspect of the system is twofold: Volatile organic contaminants will be removed from the cabin air via catalytic oxidation in the vapor phase, prior to their absorption into the aqueous phase, and vapor compression distillation technology will be used to process the condensate and hygiene waste streams in addition to the urine waste stream. Oxidation kinetics dictate that removal of volatile organic contaminants from the vapor phase is more efficient. Treatment of the various waste streams by VCD will reduce the load on the expendable ion exchange and adsorption media which follow, and on the aqueous-phase volatile removal assembly further downstream. Incorporating these advantages will reduce the weight, volume, and power requirements of the system, as well as resupply

Predictors of attitudes toward physical activity as a function of secondary school physical education experiences among adults /

Adviser: Mark Anshel.The purpose of this study was to examine the extent to which adult attitudes toward physical activity (AATPA) is a function of secondary school physical education experiences (SSPEE). A 55-item online survey was used to ascertain adults' current attitude toward exercise based on their experiences as secondary school students. The Situational Motivation Scale (Guay, Vallerand, & Blanchard, 2000) and Academic Emotions Questionnaire (Pekrun, Goetz, Titz, & Perry, 2002) were administered to 700 adults, ages 18 to 77 (M = 41.5, SD = 11.7). A hierarchical multiple linear regression (MLR), tested five models, including perceived competence (PC) and intrinsic motivation (IM). Results indicated attitudes toward experiences in secondary school physical education (PE) predicted exercise behavior. MLR analysis indicated a significant relationship between SSPEE and AATPA (p = .000). In particular, negative experiences in secondary school PE were related to negative attitudes toward physical activity. Further, PC (p = .002) and IM (p = .000) during SSPEE predicted AATPA, however, SSPEE was not significant to AATPA when PC was entered into the model. One implication of this study is that secondary school PE programs are not successful in promoting positive attitudes toward physical activity, partly explaining decisions by adults to lead a sedentary lifestyle. Physical education teacher education (PETE) programs need to teach PE majors strategies for promoting lifelong physical activity, and enhance student intrinsic motivation and perceived competence in secondary school PE programs.Ph.D

Letter to the Editor: Variances in Sagittal Femoral Shaft Bowing in Patients Undergoing TKA

published_or_final_versionSpringer Open Choice, 25 May 201

Propfan test assessment propfan propulsion system static test report

The propfan test assessment (PTA) propulsion system successfully completed over 50 hours of extensive static ground tests, including a 36 hour endurance test. All major systems performed as expected, verifying that the large-scale 2.74 m diameter propfan, engine, gearbox, controls, subsystems, and flight instrumentation will be satisfactory with minor modifications for the upcoming PTA flight tests on the GII aircraft in early 1987. A test envelope was established for static ground operation to maintain propfan blade stresses within limits for propfan rotational speeds up to 105 percent and power levels up to 3880 kW. Transient tests verified stable, predictable response of engine power and propfan speed controls. Installed engine TSFC was better than expected, probably due to the excellent inlet performance coupled with the supercharging effect of the propfan. Near- and far-field noise spectra contained three dominant components, which were dependent on power, tip speed, and direction. The components were propfan blade tones, propfan random noise, and compressor/propfan interaction noise. No significant turbine noise or combustion noise was evident

More Efficient Lattice-Based Zero-Knowledge Proofs with Straight-Line Extractability

In this work, we present a concretely efficient lattice-based zero-knowledge proof system that satisfies straight-line extractability. At the heart of our construction is a novel, non-generic application of the Katsumata transform (CRYPTO 2021) to the widely adopted zero-knowledge framework of Lyubashevsky, Nguyen and Plançon (CRYPTO 2022). Our approach significantly optimizes the proof size, achieving a 2X reduction compared to prior generic techniques. This makes our scheme particularly well-suited for anonymous credential systems, secure multi-party computation, and proving quantum security, where straight-line extractability is essential