Independent Orbiter Assessment (IOA): Assessment of the data processing system FMEA/CIL

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Data Processing System (DPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison is documented for the Orbiter DPS hardware

Independent Orbiter Assessment (IOA): Analysis of the DPS subsystem

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis/Critical Items List (FMEA/CIL) is presented. The IOA approach features a top-down analysis of the hardware to independently determine failure modes, criticality, and potential critical items. The independent analysis results corresponding to the Orbiter Data Processing System (DPS) hardware are documented. The DPS hardware is required for performing critical functions of data acquisition, data manipulation, data display, and data transfer throughout the Orbiter. Specifically, the DPS hardware consists of the following components: Multiplexer/Demultiplexer (MDM); General Purpose Computer (GPC); Multifunction CRT Display System (MCDS); Data Buses and Data Bus Couplers (DBC); Data Bus Isolation Amplifiers (DBIA); Mass Memory Unit (MMU); and Engine Interface Unit (EIU). The IOA analysis process utilized available DPS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Due to the extensive redundancy built into the DPS the number of critical items are few. Those identified resulted from premature operation and erroneous output of the GPCs

A head restraint device for vestibular studies

Head restraint device based on vacuum bladder technique for use in vestibular studie

Independent Orbiter Assessment (IOA): Analysis of the orbiter main propulsion system

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Main Propulsion System (MPS) hardware are documented. The Orbiter MPS consists of two subsystems: the Propellant Management Subsystem (PMS) and the Helium Subsystem. The PMS is a system of manifolds, distribution lines and valves by which the liquid propellants pass from the External Tank (ET) to the Space Shuttle Main Engines (SSMEs) and gaseous propellants pass from the SSMEs to the ET. The Helium Subsystem consists of a series of helium supply tanks and their associated regulators, check valves, distribution lines, and control valves. The Helium Subsystem supplies helium that is used within the SSMEs for inflight purges and provides pressure for actuation of SSME valves during emergency pneumatic shutdowns. The balance of the helium is used to provide pressure to operate the pneumatically actuated valves within the PMS. Each component was evaluated and analyzed for possible failure modes and effects. Criticalities were assigned based on the worst possible effect of each failure mode. Of the 690 failure modes analyzed, 349 were determined to be PCIs

An Exploratory Investigation of the Learning Styles of Students In an On-Line Degree Program

This study is an exploratory investigation into whether different leaning styles predict performance in an online course. Students enrolled in several cohorts of an accredited MBA program were surveyed with regard to their learning styles and those styles were correlated with the grades earned in the course. The program is unique in that the entire program could be completed online

Evaluating the Usability of Union Web Sites in the United States: A Case Study

Union membership has undergone a dramatic decline and some have hailed the internet as a means for unions to reverse their membership declines. This study examines the usability of union websites. The content of union websites has been analyzed, but the usefulness of that content, and the overall usability of the websites, has not been assessed. In order for unions to fully utilize the internet and realize the potential benefits of cyberspace usage, they must provide websites that users find easy to use and that provide useful content. This study employs Hassan and Li\u27s (2005) benchmarking approach in order to evaluate usability and content usefulness of union websites. Hassan and Li\u27s (2005) framework assesses screen appearance, media use, interactivity, accessibility, navigation, consistency, and content usefulness. This framework was applied to the websites of four U.S. unions: a craft union, a service sector union, a manufacturing sector union, and a public sector union. The results indicated that some unions may be missing up to one-third of the criteria deemed important by experts in the area of usability

Advanced Thermal Control & Systems Design Enable Long Duration, Continuous Lunar Surface Operation of Robotic Science Landers and Payloads

No abstract availabl

Assessing the Usability of Union Web Sites

This study examines the usability of union websites. Unions have suffered steep declines in membership, and some see the internet as a potential ally in the attempt to reverse these declines. However, there are questions concerning unions’ use of cyberspace to revitalize organizing. This study applies the Microsoft Usability Guidelines in a framework developed by Agarwal and Venkatesh (2002) to assess the usability of union websites. The union sites examined in this study scored high in terms of usability, when compared to previously assessed sites, indicating that unions are putting effort into creating useful web sites

Dysfunctional stem and progenitor cells impair fracture healing with age

Successful fracture healing requires the simultaneous regeneration of both the bone and vasculature; mesenchymal stem cells (MSCs) are directed to replace the bone tissue, while endothelial progenitor cells (EPCs) form the new vasculature that supplies blood to the fracture site. In the elderly, the healing process is slowed, partly due to decreased regenerative function of these stem and progenitor cells. MSCs from older individuals are impaired with regard to cell number, proliferative capacity, ability to migrate, and osteochondrogenic differentiation potential. The proliferation, migration and function of EPCs are also compromised with advanced age. Although the reasons for cellular dysfunction with age are complex and multidimensional, reduced expression of growth factors, accumulation of oxidative damage from reactive oxygen species, and altered signaling of the Sirtuin-1 pathway are contributing factors to aging at the cellular level of both MSCs and EPCs. Because of these geriatric-specific issues, effective treatment for fracture repair may require new therapeutic techniques to restore cellular function. Some suggested directions for potential treatments include cellular therapies, pharmacological agents, treatments targeting age-related molecular mechanisms, and physical therapeutics. Advanced age is the primary risk factor for a fracture, due to the low bone mass and inferior bone quality associated with aging; a better understanding of the dysfunctional behavior of the aging cell will provide a foundation for new treatments to decrease healing time and reduce the development of complications during the extended recovery from fracture healing in the elderly

Complexity of Fetal Movement Detection Using a Single Doppler Ultrasound Transducer

The objective of this paper is to discuss the complexity of fetal movement detection encountered during development and implementation of an automated single Doppler ultrasonic transducer based instrument. The single transducer instrument was intended to better quantify the duration, velocity, and magnitude of fetal movements. A Corometrics Model 116 fetal heart rate monitor was modified, and a fetal movement detection algorithm (Russell Algorithm) was developed to detect fetal movements on one and two (data fusion) transducers. A Hewlett-Packard (HP) M-1350-A fetal monitor and the Russell Algorithm were used to detect and record fetal movements concurrently on sixty patients between the gestation ages of31 to 41 weeks. Using a computer-controlled SVHS PC-VCR, the instrumental detection of fetal movements was time-linked with real-time video ultrasound. This allowed the fetal movements to be scored by expert examiners on a second-per-second basis. A total of 52,478 seconds of fetal movements was scored using this system. Neither system could accurately define the entire duration, velocity, or magnitude of the fetal movements as detected by real-time ultrasound. The complexity of detecting fetal movements using only one transducer has many shortcomings, such as: the amplitude of the returning Doppler signal, the small area of the fetus monitored by a single transducer, the position of the fetus, the type and variety of fetal movements, and material size and shape