Propellant Off-Gassing and Implications for Triage and Rescue

2020 ◽  
Vol 91 (12) ◽  
pp. 956-961
Author(s):  
Hansjrg Schwertz ◽  
Lisa A. Roth ◽  
Daniel Woodard
Keyword(s):  
Space Shuttle ◽  
Significant Risk ◽  
Space Suit ◽  
Exterior Surface ◽  
Adverse Health Effects ◽  
Medical Evacuation ◽  
Dinitrogen Tetroxide ◽  
Space Launch ◽  
Experimental Parameters ◽  
Hypergolic Propellants

INTRODUCTION: Hypergolic propellants can be released in large amounts during space launch contingencies. Whether propellant-contaminated suit fabric poses a significant risk to rescue crews, due to off-gassing, has not been explored in detail. In this study, we addressed this issue experimentally, exposing space suit fabric to propellants (dinitrogen tetroxide [N2O4] and monomethyl hydrazine [MMH]).METHODS: The NASA Space Shuttle Program Advanced Crew Escape System II (ACES II) is similar to the NASA Orion Crew Survival System (OCSS) and was utilized here. Suit fabric was placed and sealed into permeation cells. Fabric exterior surface was exposed to constant concentrated hypergolics, simulating permeation and leakage. Fabric was rinsed, and permeation and off-gassing kinetics were measured. Experimental parameters were selected, simulating suited flight crewmembers during an evacuation transport without cabin air flow.RESULTS: The fabric allows for immediate permeation of liquid or vaporized MMH and N2O4. NO2 off-gassing never exceeded the AEGL-1 8-h level (acute exposure guideline level). In contrast, MMH off-gassing levels culminated in peak levels, approaching AEGL-2 10-min levels, paralleling the drying process of the fabric layers. DISCUSSION: Our findings demonstrate that MMH off-gassing is promoted by the drying of suit material in a delayed fashion, resulting in MMH concentrations having the potential for adverse health effects for flight and rescue crews. This indicates that shorter decontamination times could be implemented, provided that suit material is either kept moist to prevent off-gassing or removed prior to medical evacuation. Additional studies using OCSS or commercial crew suits might be needed in the future.Schwertz H, Roth LA, Woodard D. Propellant off-gassing and implications for triage and rescue. Aerosp Med Hum Perform. 2020; 91(12):956961.

Launch Vehicles of the Future: Earth to Near-Earth Space

1990 ◽  
Vol 123 ◽  
pp. 347-354
Author(s):  
G. A. Keyworth
Keyword(s):  
Space Shuttle ◽  
Hubble Space Telescope ◽  
National Policy ◽  
Launch Vehicles ◽  
Space Telescope ◽  
Earth Space ◽  
Near Earth Space ◽  
Space Launch ◽  
The Future ◽  
The U.S

None of us thought, when this colloquium was scheduled, that the timing would enable it to become a celebration as well. The launch, after years of postponements, of the Hubble Space Telescope, has cast a galactic glow over the proceedings here this week. But at the same time, the frustrating delays caused by the collapse in 1986 and very slow regeneration of the U.S. space launch capabilities since then make this discussion of near-earth access very pointed.As we know, the sheer momentum of the U.S. Space Shuttle Program has dominated our perceptions of space launch for a decade and a half. It reached its peak in the early 1980s when our national policy placed nearly total reliance on the Shuttle as our means of access to space. It was a policy doomed to fail, for obvious and not-so-obvious reasons.

Pressure mode analysis of nonuniform cross-sectional pipes and preliminary evaluation of a pogo suppressor

2019 ◽  
Vol 233 (12) ◽  
pp. 4447-4456
Author(s):  
SangGu Lee ◽  
SiHun Lee ◽  
SangJoon Shin ◽  
Youdan Kim ◽  
Soogab Lee
Keyword(s):  
Natural Frequencies ◽  
Space Shuttle ◽  
Resonance Region ◽  
Mode Analysis ◽  
Preliminary Evaluation ◽  
Pressure Amplitude ◽  
Cross Sectional ◽  
Longitudinal Modes ◽  
Space Launch ◽  
Engine System

The pogo phenomenon is a type of instability that arises when the longitudinal modes of a space launch vehicle fuselage resonate with the pressure modes of the feedline in its propulsion system, with such resonance re-exciting the fuselage structure. To analyze this phenomenon, this paper specifically focuses on an analysis of the pressure modes in the space shuttle interpump line included in the LOX engine system. Because the interpump line is connected to pipes in different cross-sectional areas, the pressure modes are analyzed as a nonuniform cross-sectional pipe. Further, by applying a pogo suppressor in the feedline system, the possibility of preventing the pogo phenomenon is demonstrated. In order to design the suppressor, the resistive accumulator inertance, compliance, and resistance are considered as variables. Resistive accumulator compliance and inertance are determined and the pressure perturbation of the engine is prevented by lowering the inlet pressure amplitude of the high-pressure oxidizer pump (HPOP) in the space shuttle LOX system interpump line. When the resistive accumulator resistance is increased, the pressure frequencies of the interpump line gradually decrease, avoiding the resonance region with the fuselage. As a result, the resonance region with the fuselage is prevented by varying the pressure amplitude and natural frequencies of the interpump line. In this way, the capability of the present pogo suppression is evaluated.

scholarly journals Explosions, Burn Injuries and Adverse Health Effects of Electronic Nicotine Delivery Systems: A Review of Current Regulations and Future Perspectives

2021 ◽  
Vol 24 ◽  
pp. 462-474
Author(s):  
Ayesha Rahman Ahmed ◽  
Beverly Etchey ◽  
Mahiba Ahmed
Keyword(s):  
Health Effects ◽  
Significant Risk ◽  
The United States ◽  
Delivery Systems ◽  
Long Term Effects ◽  
Safe Alternative ◽  
Electronic Nicotine Delivery Systems ◽  
Adverse Health Effects ◽  
Adverse Health ◽  
Nicotine Delivery

Purpose: While there is a declining trend in the use of traditional methods of smoking tobacco, electronic nicotine delivery systems (ENDS) have gained popularity worldwide. ENDS are marketed as safe for the primary reason that they do not contain the well-established toxic ingredients found in traditional cigarettes. However, growing concerns over incidences of fire and explosion with specific types of ENDS, as well as their short and long-term effects, remain unaddressed. This review examines the under studied role of customized components such as batteries, e-liquid compositions, and methods of nicotine delivery that result in physical injuries and adverse health effects of ENDS. Methods: Using online reference databases (Web of Science, PubMed, Medline other, Google scholar, FDA website, FDA register), we analyzed the mechanisms through which ENDS may pose significant risk to human health. Results: An increase in the use and popularity of ENDS has been observed among youth and adults in the United States since 2007. The ENDS devices available to the public allow for custom alterations which can introduce incompatible components, resulting in overheating and explosion related injuries. Heavy metals have been found to leach from some devices into the e-liquid, and the heating of e-liquid ingredients can produce toxic byproducts. Conclusions: Overall, the current literature demonstrates that ENDS are not a safe alternative to traditional cigarettes due to explosion risks and negative health effects including addiction, adverse respiratory and cardiovascular effects, heavy metal leaching, and toxic byproducts exposure. These risks warrant regulation of ENDS devices and formulations, with urgency underscored by their increasing popularity among youth and adults.

scholarly journals Recognizing and Preventing Overexposure to Methylmercury from Fish and Seafood Consumption: Information for Physicians

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Susan M. Silbernagel ◽  
David O. Carpenter ◽  
Steven G. Gilbert ◽  
Michael Gochfeld ◽  
Edward Groth ◽  
...  
Keyword(s):  
Nervous System ◽  
Fish Consumption ◽  
Hair Analysis ◽  
Significant Risk ◽  
Seafood Consumption ◽  
Specific Diagnosis ◽  
Adverse Health Effects ◽  
Methylmercury Exposure ◽  
Methylmercury Poisoning ◽  
Current Advice

Fish is a valuable source of nutrition, and many people would benefit from eating fish regularly. But some people eat a lot of fish, every day or several meals per week, and thus can run a significant risk of overexposure to methylmercury. Current advice regarding methylmercury from fish consumption is targeted to protect the developing brain and nervous system but adverse health effects are increasingly associated with adult chronic low-level methylmercury exposure. Manifestations of methylmercury poisoning are variable and may be difficult to detect unless one considers this specific diagnosis and does an appropriate test (blood or hair analysis). We provide information to physicians to recognize and prevent overexposure to methylmercury from fish and seafood consumption. Physicians are urged to ask patients if they eat fish: how often, how much, and what kinds. People who eat fish frequently (once a week or more often) and pregnant women are advised to choose low mercury fish.

scholarly journals Weld Residual Stress and Distortion Analysis of the ARES I-X Upper Stage Simulator (USS)

2008 ◽  
Author(s):  
Frederick W. Brust ◽  
Ivatury Raju ◽  
Derrick Cheston ◽  
David Dawicke ◽  
Dawn Phillips
Keyword(s):  
Residual Stresses ◽  
Space Shuttle ◽  
Launch Vehicles ◽  
Weld Residual Stress ◽  
Distortion Analysis ◽  
Space Launch ◽  
The Us ◽  
Upper Stage ◽  
Space Launch Vehicles ◽  
Ares I

An independent assessment was conducted to determine the critical initial flaw size (CIFS) for the flange-to-skin weld in the Ares I-X Upper Stage Simulator (USS). The Ares system of space launch vehicles is the US National Aeronautics and Space Administration’s plan for replacement of the aging space shuttle. The new Ares space launch system is somewhat of a combination of the space shuttle system and the Saturn launch vehicles used prior to the shuttle. Here, a series of weld analyses are performed to determine the residual stresses in a critical region of the USS. Weld residual stresses both increase constraint and mean stress thereby having an important effect on fatigue and fracture life. While the main focus of this paper is a discussion of the weld modeling procedures and results for the USS, a short summary of the CIFS assessment is provided.

The effect of back-melting on the continuity of crystallographic orientation and composition in HgZnTe

1992 ◽  
Vol 50 (2) ◽  
pp. 1696-1697
Author(s):  
H.J. Zuo ◽  
M.W. Price ◽  
R.D. Griffin ◽  
R.A. Andrews ◽  
G.M. Janowski
Keyword(s):  
Directional Solidification ◽  
Space Shuttle ◽  
Solidification Process ◽  
Space Experiment ◽  
Infrared Detection ◽  
Directionally Solidified ◽  
Crystallographic Defects ◽  
Semiconducting Alloys ◽  
Uniform Composition ◽  
Growth Experiments

The II-VI semiconducting alloys, such as mercury zinc telluride (MZT), have become the materials of choice for numerous infrared detection applications. However, compositional inhomogeneities and crystallographic imperfections adversly affect the performance of MZT infrared detectors. One source of imperfections in MZT is gravity-induced convection during directional solidification. Crystal growth experiments conducted in space should minimize gravity-induced convection and thereby the density of related crystallographic defects. The limited amount of time available during Space Shuttle experiments and the need for a sample of uniform composition requires the elimination of the initial composition transient which occurs in directionally solidified alloys. One method of eluding this initial transient involves directionally solidifying a portion of the sample and then quenching the remainder prior to the space experiment. During the space experiment, the MZT sample is back-melted to exactly the point at which directional solidification was stopped on earth. The directional solidification process then continues.

1266: Do Anatomical Factors Pose a Significant Risk in the Formation of Lower Pole Stones?

2007 ◽  
Vol 177 (4S) ◽  
pp. 417-417
Author(s):  
Ramaswamy Manikandan ◽  
Thiruenderan Thirugunenderan ◽  
Zara Gall ◽  
Donald Neilson ◽  
Adebanji Adeyoju
Keyword(s):  
Significant Risk ◽  
Lower Pole
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