12 results on '"Dokos, Adam"'
Search Results
2. Dust and Debris Tolerant Retractable Cover Connector
- Author
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Lewis, Mark E, Dokos, Adam G, Townsend, III, Ivan I, Carlson, Jeffrey W, Bastin, Gary L, and Murtland, Kevin A
- Subjects
Electronics And Electrical Engineering - Abstract
A debris exclusion and removal apparatus for connectors which have retractable cover configurations which include internal wafers that clean the connectors prior to mating. XXXX connectors. More particularly, embodiments relate to dust tolerant connectors. Some embodiments also relate to an intelligent connector system capable of detecting damage to or faults within a conductor and then rerouting the energy to a non-damaged spare conductor. Discussion Connectors of the present invention may be used to transfer electrical current, fluid, and gas in a wide variety of environments containing dust and other debris, wherein that debris may present substantial challenges. For example, lunar/Martian dust intrusion and/or accumulation in connectors used to transfer oxygen, hydrogen, nitrogen, etc., may lead to larger system failures as well as loss of life in extraterrestrial human exploration endeavors. Additionally, embodiments of the present invention may also be suitable for use where connectors must resist water intrusion, such as terrestrial deep water operations.
- Published
- 2017
3. Insulation Test Cryostat with Lift Mechanism
- Author
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Fesmire, James E and Dokos, Adam G
- Subjects
Fluid Mechanics And Thermodynamics - Abstract
A multi-purpose, cylindrical thermal insulation test apparatus is used for testing insulation materials and systems of materials using a liquid boil-off calorimeter system for absolute measurement of the effective thermal conductivity (k-value) and heat flux of a specimen material at a fixed environmental condition (cold-side temperature, warm-side temperature, vacuum pressure level, and residual gas composition). An inner vessel receives liquid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including upper and lower guard chambers and middle test vessel, is suspended from a lid of the vacuum canister. Each of the three chambers is filled and vented through a single feedthrough. All fluid and instrumentation feedthroughs are mounted and suspended from a top domed lid allowing easy removal of the cold mass. A lift mechanism allows manipulation of the cold mass assembly and insulation test article.
- Published
- 2016
4. Dust Tolerant Connectors
- Author
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Mueller, Robert P, Lewis, Mark E, Bastin, Gary L, Branch, Matthew C, Carlson, Jeffrey W, Dokos, Adam G, Murtland, Kevin A, Nugent, Matthew W, Tamasy, Gabor J, and Townsend, III, Ivan I
- Subjects
Electronics And Electrical Engineering - Abstract
Methods and systems may provide for debris exclusion and removal apparatuses for connectors which have inverting end caps with a multi-axis lever configuration, inverting end caps with enlarged handle and/or side rail configurations, rotating end cap configurations, poppet valve configurations, O-ring configurations, filament barrier configurations, retractable cover configurations, clamshell end cap configurations, or any combination thereof. Apparatuses may also provide for an intelligent electrical connector system capable of detecting damage to or faults within a plurality of conductors and then rerouting the energy through a non-damaged spare conductor.
- Published
- 2016
5. Cratering of Soil by Impinging Jets of Gas, with Application to Landing Rockets on Planetary Surfaces
- Author
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Metzger, Philip T., Vu, Bruce T., Taylor, D. E., Kromann, M. J., Fuchs, M., Yutko, B., Dokos, Adam, Immer, Christopher D., Lane, John E., Dunkel, M. B., Donahue, Carly M., and Latta, Robert C.
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Statistical Mechanics (cond-mat.stat-mech) ,Fluid Dynamics (physics.flu-dyn) ,FOS: Physical sciences ,Physics - Fluid Dynamics ,Condensed Matter - Statistical Mechanics ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Several physical mechanisms are involved in excavating granular materials beneath a vertical jet of gas. These occur, for example, beneath the exhaust plume of a rocket landing on the soil of the Moon or Mars. A series of experiments and simulations have been performed to provide a detailed view of the complex gas/soil interactions. Measurements have also been taken from the Apollo lunar landing videos and from photographs of the resulting terrain, and these help to demonstrate how the interactions extrapolate into the lunar environment. It is important to understand these processes at a fundamental level to support the on-going design of higher-fidelity numerical simulations and larger-scale experiments. These are needed to enable future lunar exploration wherein multiple hardware assets will be placed on the Moon within short distances of one another. The high-velocity spray of soil from landing spacecraft must be accurately predicted and controlled lest it erosively damage the surrounding hardware., 6 pages, 5 figures
- Published
- 2021
6. Insulation Test Cryostat with Lift Mechanism
- Author
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Fesmire, James E and Dokos, Adam G
- Subjects
Instrumentation And Photography ,Fluid Mechanics And Thermodynamics - Abstract
A multi-purpose, cylindrical thermal insulation test apparatus is used for testing insulation materials and systems of materials using a liquid boil-off calorimeter system for absolute measurement of the effective thermal conductivity (k-value) and heat flux of a specimen material at a fixed environmental condition (cold-side temperature, warm-side temperature, vacuum pressure level, and residual gas composition). The apparatus includes an inner vessel for receiving a liquid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including the upper and lower guard chambers and a middle test vessel, is suspended from a lid of the vacuum canister. Each of the three chambers is filled and vented through a single feedthrough. All fluid and instrumentation feedthroughs are mounted and suspended from a top domed lid to allow easy removal of the cold mass. A lift mechanism allows manipulation of the cold mass assembly and insulation test article.
- Published
- 2014
7. Composite Overview and Composite Aerocover Overview
- Author
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Caraccio, Anne, Tate, LaNetra, Dokos, Adam, Taylor, Brian, and Brown, Chad
- Subjects
Composite Materials - Abstract
Materials Science Division within the Engineering Directorate tasked by the Ares Launch Vehicle Division (LX-V) and the Fluids Testing and Technology Development Branch (NE-F6) to design, fabricate and test an aerodynamic composite shield for potential Heavy Lift Launch Vehicle infusion and a composite strut that will serve as a pathfinder in evaluating calorimeter data for the CRYOSTAT (cryogenic on orbit storage and transfer) Project. ATP project is to carry the design and development of the aerodynamic composite cover or "bracket" from cradle to grave including materials research, purchasing, design, fabrication, testing, analysis and presentation of the final product. Effort consisted of support from the Materials Testing & Corrosion Control Branch (NE-L2) for mechanical testing, the Prototype Development Branch (NE-L3) for CAD drawing, design/analysis, and fabrication, Materials & Processes Engineering Branch (NE-L4) for project management and materials selection; the Applied Physics Branch (NE-LS) for NDE/NDI support; and the Chemical Analysis Branch (NE-L6) for developmental systems evaluation. Funded by the Ares Launch Vehicle Division and the Fluids Testing and Technology Development Branch will provide ODC
- Published
- 2014
8. Dust-Tolerant Intelligent Electrical Connection System
- Author
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Lewis, Mark, Dokos, Adam, Perotti, Jose, Calle, Carlos, Mueller, Robert, Bastin, Gary, Carlson, Jeffrey, Townsend, Ivan, III, Immer, Chirstopher, and Medelius, Pedro
- Subjects
Electronics And Electrical Engineering - Abstract
Faults in wiring systems are a serious concern for the aerospace and aeronautic (commercial, military, and civilian) industries. Circuit failures and vehicle accidents have occurred and have been attributed to faulty wiring created by open and/or short circuits. Often, such circuit failures occur due to vibration during vehicle launch or operation. Therefore, developing non-intrusive fault-tolerant techniques is necessary to detect circuit faults and automatically route signals through alternate recovery paths while the vehicle or lunar surface systems equipment is in operation. Electrical connector concepts combining dust mitigation strategies and cable diagnostic technologies have significant application for lunar and Martian surface systems, as well as for dusty terrestrial applications. The dust-tolerant intelligent electrical connection system has several novel concepts and unique features. It combines intelligent cable diagnostics (health monitoring) and automatic circuit routing capabilities into a dust-tolerant electrical umbilical. It retrofits a clamshell protective dust cover to an existing connector for reduced gravity operation, and features a universal connector housing with three styles of dust protection: inverted cap, rotating cap, and clamshell. It uses a self-healing membrane as a dust barrier for electrical connectors where required, while also combining lotus leaf technology for applications where a dust-resistant coating providing low surface tension is needed to mitigate Van der Waals forces, thereby disallowing dust particle adhesion to connector surfaces. It also permits using a ruggedized iris mechanism with an embedded electrodynamic dust shield as a dust barrier for electrical connectors where required.
- Published
- 2012
9. Portable Handheld Optical Window Inspection Device
- Author
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Ihlefeld, Curtis, Dokos, Adam, and Burns, Bradley
- Subjects
Instrumentation And Photography - Abstract
The Portable Handheld Optical Window Inspection Device (PHOWID) is a measurement system for imaging small defects (scratches, pits, micrometeor impacts, and the like) in the field. Designed primarily for window inspection, PHOWID attaches to a smooth surface with suction cups, and raster scans a small area with an optical pen in order to provide a three-dimensional image of the defect. PHOWID consists of a graphical user interface, motor control subsystem, scanning head, and interface electronics, as well as an integrated camera and user display that allows a user to locate minute defects before scanning. Noise levels are on the order of 60 in. (1.5 m). PHOWID allows field measurement of defects that are usually done in the lab. It is small, light, and attaches directly to the test article in any orientation up to vertical. An operator can scan a defect and get useful engineering data in a matter of minutes. There is no need to make a mold impression for later lab analysis.
- Published
- 2010
10. Inline Electrical Connector Mate/Demate Pliers
- Author
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Yutko, Brian, Dininny, Michael, Moscoso, Gerand, and Dokos, Adam
- Subjects
Man/System Technology And Life Support - Abstract
Military and aerospace industries use Mil-Spec type electrical connections on bulkhead panels that require inline access for mate and demate operations. These connectors are usually in tight proximity to other connectors, or recessed within panels. The pliers described here have been designed to work in such tight spaces, and consist of a mirrored set of parallel handles, two cross links, two return springs, and replaceable polyurethane-coated end effectors. The polyurethane eliminates metal-to-metal contact and provides a high-friction surface between the jaw and the connector. Operationally, the user would slide the pliers over the connector shell until the molded polyurethane lip makes contact with the connector shell edge. Then, by squeezing the handles, the end effector jaws grip the connector shell, allowing the connector to be easily disconnected by rotating the pliers. Mating the connector occurs by reversing the prescribed procedure, except the connector shell is placed into the jaws by hand. The molded lip within the jaw allows the user to apply additional force for difficult-to-mate connectors. Handle design has been carefully examined to maximize comfort, limit weight, incorporate tether locations, and improve ergonomics. They have been designed with an off-axis offset for wiring harness clearance, while placing the connector axis of rotation close to the user s axis of wrist rotation. This was done to eliminate fatigue during multiple connector panel servicing. To limit handle opening width, with user ergonomics in mind, the pliers were designed using a parallel jaw mechanism. A cross-link mechanism was used to complete this task, while ensuring smooth operation.
- Published
- 2010
11. Insulation-Testing Cryostat With Lifting Mechanism
- Author
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Fesmire, James, Dokos, Adam, Scholtens, Brekke, Nagy, Zoltan, and Augustynowicz, Stanislaw
- Subjects
Man/System Technology And Life Support - Abstract
The figure depicts selected aspects of an apparatus for testing thermal-insulation materials for cryogenic systems at temperatures and under vacuum or atmospheric conditions representative of those encountered in use. This apparatus, called "Cryostat-100," is based on the established cryogen-boil-off calorimeter method, according to which the amount of heat that passes through an insulation specimen to a cryogenic fluid in a container, and thus the effective thermal conductance of the specimen, is taken to be proportional to the amount of the cryogenic fluid that boils off from the container. The design of Cryostat-100 is based partly on, and incorporates improvements over, the design of a similar prior apparatus called "Cryostat-1" described in "Improved Methods of Testing Cryogenic Insulation Materials" (KSC-12107 & KSC- 12108), NASA Tech Briefs, Vol. 24, No. 12 (December 2000), page 46. The design of Cryostat-100 also incorporates the best features of two other similar prior apparatuses called "Cryostat-2" (also described in the cited prior article) and "Cryostat- 4." Notable among the improvements in Cryostat-100 is the addition of a lifting mechanism that enables safe, rapid, reliable insertion and removal of insulation specimens and facilitates maintenance operations that involve lifting. As in Cryostat-1, the cold mass is a vertical stainless-steel cylindrical vessel subdivided into a larger measurement vessel with smaller thermal-guard vessels at both ends. During operation, all three vessels are kept filled with liquid nitrogen near saturation at ambient pressure (temperature .77.4 K). The cold mass of Cryostat-100 has a length of 1 m and diameter of 168 mm. Each specimen has a corresponding nominal length and inner diameter and a nominal thickness of 25.4 mm. Specimens that are shorter and have thicknesses between 0 and 50 mm are also acceptable. Bulk-fill, foam, clam-shell, multilayer insulation, and layered materials can be tested over a very wide range of thermal transmission: apparent thermal conductivity from 0.01 to 60 mW/m-K and heat flux from 0.1 to 500 W/sq m. A test in Cryostat-100 can be conducted at any desired gas pressure between ambient atmospheric pressure at one extreme and a vacuum with residual pressure <10(exp -5) torr (<1.33 10(exp -3) Pa) at the other extreme. The residual gas (and purge gas) is typically nitrogen, but can be any suitable purge gas (e.g., helium, argon, or carbon dioxide). Usually, the temperature on the warm boundary of the insulation specimen is maintained near the ambient value (approximately 293 K), while the boiling of liquid nitrogen at atmospheric pressure in the cold mass maintains the temperature on the cold boundary of the specimen at approximately 77 K.
- Published
- 2010
12. A Balloon-Based Payload for Exposing Microorganisms in the Stratosphere (E-MIST).
- Author
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Smith, David J., Thakrar, Prital J., Bharrat, Anthony E., Dokos, Adam G., Kinney, Teresa L., James, Leandro M., Lane, Michael A., Khodadad, Christina L., Maguire, Finlay, Maloney, Phillip R., and Dawkins, Nicole L.
- Subjects
ROCKET payloads ,MICROORGANISMS ,SPACE vehicles ,STRATOSPHERE ,MARTIAN atmosphere - Abstract
The survival and transit of microorganisms in Earth's upper atmosphere is relevant to terrestrial ecology and astrobiology, but the topic is understudied due to a scarcity of suitable flight systems. We designed, built, and flew a self-contained payload, Exposing Microorganisms in the Stratosphere (E-MIST), on a large scientific balloon launched from New Mexico on 24 August 2014. The payload carried Bacillus pumilus SAFR-032, a highly-resilient spore-forming bacterial strain originally isolated from a NASA spacecraft assembly facility. Our test flight evaluated E-MIST functionality in the stratosphere, including microbiological procedures and overall instrument performance. Herein, we summarize features of the E-MIST payload, protocols, and preliminary results that indicate it is possible to conduct a tightly-controlled microbiological experiment in the stratosphere while collecting pertinent environmental data. Additional studies of this nature may permit survival models for microbes traveling through Earth's harsh upper atmosphere. Moreover, measuring the endurance of spacecraft- associated microbes at extreme altitudes may help predict their response on the surface of Mars. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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