Docking Fixture and Mechanism for a Protective Suit

A suitlock assembly that comprises a docking fixture and mechanism has been invented to facilitate and accelerate donning and doffing of a sealed protective suit and/or to enable ingress and egress between the protective suit and a sealed vessel. The sealed protective suit could be a space suit, in which case the sealed vessel could be a spacecraft. Alternatively, the sealed suit could be an environmental protective suit of a type worn on Earth during cleanup of a hazardous-material site, in which case the sealed vessel could be a vehicle equipped to maintain a safe interior environment for workers in transit to and from the site. Figure 1 depicts a typical situation in which several crewmembers are working inside such a vehicle, one is working outside in a protective suit, and one is donning or doffing a protective suit while holding onto an overhead bar for support

Suitlock Docking Mechanism

An environmental protective suit used for hazardous clean-up or space applications includes a suitlock docking mechanism that allows for easy egress and ingress of a crew member between a sealed vessel and a possibly contaminated environment. The suitlock docking mechanism comprises a single actuator that controls latches which, in turn, respectfully control rack and pinion assemblies that allow for easy removal and attachment of a life support equipment enclosure shell to the environmental protective suit or to the vehicle from which the operator performs his/her duties

AX-5 space suit bearing torque investigation

The symptoms and eventual resolution of a torque increase problem occurring with ball bearings in the joints of the AX-5 space suit are described. Starting torques that rose 5 to 10 times initial levels were observed in crew evaluation tests of the suit in a zero-g water tank. This bearing problem was identified as a blocking torque anomaly, observed previously in oscillatory gimbal bearings. A large matrix of lubricants, ball separator designs and materials were evaluated. None of these combinations showed sufficient tolerance to lubricant washout when repeatedly cycled in water. The problem was resolved by retrofitting a pressure compensated, water exclusion seal to the outboard side of the bearing cavity. The symptoms and possible remedies to blocking are discussed

Graphene formation on SiC substrates

Graphene layers were created on both C and Si faces of semi-insulating, on-axis, 4H- and 6H-SiC substrates. The process was performed under high vacuum (<10-4 mbar) in a commercial chemical vapor deposition SiC reactor. A method for H2 etching the on-axis sub-strates was developed to produce surface steps with heights of 0.5 nm on the Si-face and 1.0 to 1.5 nm on the C-face for each polytype. A process was developed to form graphene on the substrates immediately after H2 etching and Raman spectroscopy of these samples confirmed the formation of graphene. The morphology of the graphene is described. For both faces, the underlying substrate morphology was significantly modified during graphene formation; sur-face steps were up to 15 nm high and the uniform step morphology was sometimes lost. Mo-bilities and sheet carrier concentrations derived from Hall Effect measurements on large area (16 mm square) and small area (2 and 10 um square) samples are presented and shown to compare favorably to recent reports.Comment: European Conference on Silicon Carbide and Related Materials 2008 (ECSCRM '08), 4 pages, 4 figure

Improvement of Morphology and Free Carrier Mobility through Argon-Assisted Growth of Epitaxial Graphene on Silicon Carbide

Graphene was epitaxially grown on both the C- and Si-faces of 4H- and 6H-SiC(0001) under an argon atmosphere and under high vacuum conditions. Following growth, samples were imaged with Nomarski interference contrast and atomic force microscopies and it was found that growth under argon led to improved morphologies on the C-face films but the Si-face films were not significantly affected. Free carrier transport studies were conducted through Hall effect measurements, and carrier mobilities were found to increase and sheet carrier densities were found to decrease for those films grown under argon as compared to high vacuum conditions. The improved mobilities and concurrent decreases in sheet carrier densities suggest a decrease in scattering in the films grown under argon.Comment: 215th Meeting of the Electrochemical Society (ECS 215), 14 pages, 6 figure

Hall Effect Mobility of Epitaxial Graphene Grown on Silicon Carbide

Epitaxial graphene films were grown in vacuo by silicon sublimation from the (0001) and (000-1) faces of 4H- and 6H-SiC. Hall effect mobilities and sheet carrier densities of the films were measured at 300 K and 77 K and the data depended on the growth face. About 40% of the samples exhibited holes as the dominant carrier, independent of face. Generally, mobilities increased with decreasing carrier density, independent of carrier type and substrate polytype. The contributions of scattering mechanisms to the conductivities of the films are discussed. The results suggest that for near-intrinsic carrier densities at 300 K epitaxial graphene mobilities will be ~150,000 cm2V-1s-1 on the (000-1) face and ~5,800 cm2V-1s-1 on the (0001) face.Comment: Accepted for publication in Applied Physics Letters, 10 pages, 2 figure

ADHD presenting as recurrent epistaxis: a case report

Epistaxis is an important otorhinolaryngological emergency, which usually has an apparent etiology, frequently local trauma in children. Here we present a case report wherein the epistaxis was recalcitrant, and proved to have a psychiatric disorder as an underlying basis. The child was diagnosed with Attention Deficit/Hyperactivity Disorder, hyperactive type, which led to trauma to nasal mucosa due to frequent and uncontrolled nose picking. Treatment with atomoxetine controlled the patient's symptoms and led to a remission of epistaxis

Morphology Characterization of Argon-Mediated Epitaxial Graphene on C-face SiC

Epitaxial graphene layers were grown on the C-face of 4H- and 6H-SiC using an argon-mediated growth process. Variations in growth temperature and pressure were found to dramatically affect the morphological properties of the layers. The presence of argon during growth slowed the rate of graphene formation on the C-face and led to the observation of islanding. The similarity in the morphology of the islands and continuous films indicated that island nucleation and coalescence is the growth mechanism for C-face graphene.Comment: 12 pages, 4 figure