A Simulation Based Investigation of High Latency Space Systems Operations

NASA Technical Reports Server (NTRS)

Li, Zu Qun; Crues, Edwin Z.; Bielski, Paul; Moore, Michael

2017-01-01

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control system, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions, and to assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

The Johnson Space Center Management Information Systems (JSCMIS): An interface for organizational databases

NASA Technical Reports Server (NTRS)

Bishop, Peter C.; Erickson, Lloyd

1990-01-01

The Management Information and Decision Support Environment (MIDSE) is a research activity to build and test a prototype of a generic human interface on the Johnson Space Center (JSC) Information Network (CIN). The existing interfaces were developed specifically to support operations rather than the type of data which management could use. The diversity of the many interfaces and their relative difficulty discouraged occasional users from attempting to use them for their purposes. The MIDSE activity approached this problem by designing and building an interface to one JSC data base - the personnel statistics tables of the NASA Personnel and Payroll System (NPPS). The interface was designed against the following requirements: generic (use with any relational NOMAD data base); easy to learn (intuitive operations for new users); easy to use (efficient operations for experienced users); self-documenting (help facility which informs users about the data base structure as well as the operation of the interface); and low maintenance (easy configuration to new applications). A prototype interface entitled the JSC Management Information Systems (JSCMIS) was produced. It resides on CIN/PROFS and is available to JSC management who request it. The interface has passed management review and is ready for early use. Three kinds of data are now available: personnel statistics, personnel register, and plan/actual cost.

Enzyme activity in terrestrial soil in relation to exploration of the Martian surface

NASA Technical Reports Server (NTRS)

Mclaren, A. D.

1974-01-01

Sensitive tests for the detection of extracellular enzyme activity in Martian soil was investigated using simulated Martian soil. Enzyme action at solid-liquid water interfaces and at low humidity were studied, and a kinetic scheme was devised and tested based on the growth of microorganisms and the oxidation of ammonium nitrite.

Bidirectional neural interface: Closed-loop feedback control for hybrid neural systems.

PubMed

Chou, Zane; Lim, Jeffrey; Brown, Sophie; Keller, Melissa; Bugbee, Joseph; Broccard, Frédéric D; Khraiche, Massoud L; Silva, Gabriel A; Cauwenberghs, Gert

2015-01-01

Closed-loop neural prostheses enable bidirectional communication between the biological and artificial components of a hybrid system. However, a major challenge in this field is the limited understanding of how these components, the two separate neural networks, interact with each other. In this paper, we propose an in vitro model of a closed-loop system that allows for easy experimental testing and modification of both biological and artificial network parameters. The interface closes the system loop in real time by stimulating each network based on recorded activity of the other network, within preset parameters. As a proof of concept we demonstrate that the bidirectional interface is able to establish and control network properties, such as synchrony, in a hybrid system of two neural networks more significantly more effectively than the same system without the interface or with unidirectional alternatives. This success holds promise for the application of closed-loop systems in neural prostheses, brain-machine interfaces, and drug testing.

Stability of a chemically active floating disk

NASA Astrophysics Data System (ADS)

Vandadi, Vahid; Jafari Kang, Saeed; Rothstein, Jonathan; Masoud, Hassan

2017-11-01

We theoretically study the translational stability of a chemically active disk located at a flat liquid-gas interface. The initially immobile circular disk uniformly releases an interface-active agent that locally changes the surface tension and is insoluble in the bulk. If left unperturbed, the stationary disk remains motionless as the agent is discharged. Neglecting the inertial effects, we numerically test whether a perturbation in the translational velocity of the disk can lead to its spontaneous and self-sustained motion. Such a perturbation gives rise to an asymmetric distribution of the released factor that could trigger and sustain the Marangoni propulsion of the disk. An implicit Fourier-Chebyshev spectral method is employed to solve the advection-diffusion equation for the concentration of the active agent. The solution, given a linear equation of state for the surface tension, provides the shear stress distribution at the interface. This and the no-slip condition on the wetted surface of the disk are then used at each time step to semi-analytically determine the Stokes flow in the semi-infinite liquid layer. Overall, the findings of our investigation pave the way for pinpointing the conditions under which interface-bound active particles become dynamically unstable.

Modeling Europa's Ice-Ocean Interface

NASA Astrophysics Data System (ADS)

Elsenousy, A.; Vance, S.; Bills, B. G.

2014-12-01

This work focuses on modeling the ice-ocean interface on Jupiter's Moon (Europa); mainly from the standpoint of heat and salt transfer relationship with emphasis on the basal ice growth rate and its implications to Europa's tidal response. Modeling the heat and salt flux at Europa's ice/ocean interface is necessary to understand the dynamics of Europa's ocean and its interaction with the upper ice shell as well as the history of active turbulence at this area. To achieve this goal, we used McPhee et al., 2008 parameterizations on Earth's ice/ocean interface that was developed to meet Europa's ocean dynamics. We varied one parameter at a time to test its influence on both; "h" the basal ice growth rate and on "R" the double diffusion tendency strength. The double diffusion tendency "R" was calculated as the ratio between the interface heat exchange coefficient αh to the interface salt exchange coefficient αs. Our preliminary results showed a strong double diffusion tendency R ~200 at Europa's ice-ocean interface for plausible changes in the heat flux due to onset or elimination of a hydrothermal activity, suggesting supercooling and a strong tendency for forming frazil ice.

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- During Crew Equipment Interface Test (CEIT)activities at SPACEHAB, Cape Canaveral, Fla., STS-107 Mission Specialist Kalpana Chawla looks over equipment inside the Spacehab module. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. The CEIT activities enable the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. Other STS-107 crew members are Commander Rick Douglas Husband; Pilot William C. McCool; Payload Commander Michael P. Anderson; Mission Specialists Laurel Blair Salton Clark and David M. Brown; and Payload Specialist Ilan Ramon, of Israel. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- During Crew Equipment Interface Test (CEIT)activities at SPACEHAB, Cape Canaveral, Fla., STS-107 Mission Specialist Laurel Blair Salton Clark gets hands-on training on equipment inside the Spacehab module. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. CEIT activities enable the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. Other STS-107 crew members are Commander Rick Douglas Husband; Pilot William C. McCool; Payload Commander Michael P. Anderson; Mission Specialists Kalpana Chawla and David M. Brown; and Payload Specialist Ilan Ramon, of Israel. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- During Crew Equipment Interface Test activities at SPACEHAB, Cape Canaveral, Fla., STS-107 Mission Specialist Laurel Blair Salton Clark gets hands-on training on a glove box experiment inside the training module. As a research mission, STS-107 will carry the SPACEHAB Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. CEIT activities enable the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. Other STS-107 crew members are Commander Rick Douglas Husband; Pilot William C. McCool; Payload Commander Michael P. Anderson; Mission Specialists Kalpana Chawla and David M. Brown; and Payload Specialist Ilan Ramon, of Israel. STS-107 is scheduled for launch May 23, 2002

Structure-level fuel load assessment in the wildland-urban interface: a fusion of airborne laser scanning and spectral remote-sensing methodologies

Treesearch

Nicholas S. Skowronski; Scott Haag; Jim Trimble; Kenneth L. Clark; Michael R. Gallagher; Richard G. Lathrop

2015-01-01

Large-scale fuel assessments are useful for developing policy aimed at mitigating wildfires in the wildland-urban interface (WUI), while finer-scale characterisation is necessary for maximising the effectiveness of fuel reduction treatments and directing suppression activities. We developed and tested an objective, consistent approach for characterising hazardous fuels...

Open ISEmeter: An open hardware high-impedance interface for potentiometric detection.

PubMed

Salvador, C; Mesa, M S; Durán, E; Alvarez, J L; Carbajo, J; Mozo, J D

2016-05-01

In this work, a new open hardware interface based on Arduino to read electromotive force (emf) from potentiometric detectors is presented. The interface has been fully designed with the open code philosophy and all documentation will be accessible on web. The paper describes a comprehensive project including the electronic design, the firmware loaded on Arduino, and the Java-coded graphical user interface to load data in a computer (PC or Mac) for processing. The prototype was tested by measuring the calibration curve of a detector. As detection element, an active poly(vinyl chloride)-based membrane was used, doped with cetyltrimethylammonium dodecylsulphate (CTA(+)-DS(-)). The experimental measures of emf indicate Nernstian behaviour with the CTA(+) content of test solutions, as it was described in the literature, proving the validity of the developed prototype. A comparative analysis of performance was made by using the same chemical detector but changing the measurement instrumentation.

Generating a Reduced Gravity Environment on Earth

NASA Technical Reports Server (NTRS)

Dungan, Larry K.; Cunningham, Tom; Poncia, Dina

2010-01-01

Since the 1950s several reduced gravity simulators have been designed and utilized in preparing humans for spaceflight and in reduced gravity system development. The Active Response Gravity Offload System (ARGOS) is the newest and most realistic gravity offload simulator. ARGOS provides three degrees of motion within the test area and is scalable for full building deployment. The inertia of the overhead system is eliminated by an active motor and control system. This presentation will discuss what ARGOS is, how it functions, and the unique challenges of interfacing to the human. Test data and video for human and robotic systems will be presented. A major variable in the human machine interaction is the interface of ARGOS to the human. These challenges along with design solutions will be discussed.

Radio tuning effects on visual and driving performance measures : simulator and test track studies.

DOT National Transportation Integrated Search

2013-05-01

Existing driver distraction guidelines for visual-manual device interface operation specify traditional : manual radio tuning as a reference task. This project evaluated the radio tuning reference task through two activities. : The first activity con...

Design of efficient and simple interface testing equipment for opto-electric tracking system

NASA Astrophysics Data System (ADS)

Liu, Qiong; Deng, Chao; Tian, Jing; Mao, Yao

2016-10-01

Interface testing for opto-electric tracking system is one important work to assure system running performance, aiming to verify the design result of every electronic interface matching the communication protocols or not, by different levels. Opto-electric tracking system nowadays is more complicated, composed of many functional units. Usually, interface testing is executed between units manufactured completely, highly depending on unit design and manufacture progress as well as relative people. As a result, it always takes days or weeks, inefficiently. To solve the problem, this paper promotes an efficient and simple interface testing equipment for opto-electric tracking system, consisting of optional interface circuit card, processor and test program. The hardware cards provide matched hardware interface(s), easily offered from hardware engineer. Automatic code generation technique is imported, providing adaption to new communication protocols. Automatic acquiring items, automatic constructing code architecture and automatic encoding are used to form a new program quickly with adaption. After simple steps, a standard customized new interface testing equipment with matching test program and interface(s) is ready for a waiting-test system in minutes. The efficient and simple interface testing equipment for opto-electric tracking system has worked for many opto-electric tracking system to test entire or part interfaces, reducing test time from days to hours, greatly improving test efficiency, with high software quality and stability, without manual coding. Used as a common tool, the efficient and simple interface testing equipment for opto-electric tracking system promoted by this paper has changed traditional interface testing method and created much higher efficiency.

Controllable Grid Interface Test System | Energy Systems Integration

Science.gov Websites

Facility | NREL Controllable Grid Interface Test System Controllable Grid Interface Test System NREL's controllable grid interface (CGI) test system can reduce certification testing time and costs grid interface is the first test facility in the United States that has fault simulation capabilities

Access 5 - Step 1: Human Systems Integration Program Plan (HSIPP)

NASA Technical Reports Server (NTRS)

2005-01-01

This report describes the Human System Interface (HSI) analysis, design and test activities that will be performed to support the development of requirements and design guidelines to facilitate the incorporation of High Altitude Long Endurance (HALE) Remotely Operated Aircraft (ROA) at or above FL400 in the National Airspace System (NAS). These activities are required to support the design and development of safe, effective and reliable ROA operator and ATC interfaces. This plan focuses on the activities to be completed for Step 1 of the ACCESS 5 program. Updates to this document will be made for each of the four ACCESS 5 program steps.

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- At SPACEHAB, Cape Canaveral, Fla., the STS-107 crew takes part in Crew Equipment Interface Test (CEIT) activities. From left are Mission Specialist Laurel Blair Salton Clark, Commander Rick Douglas Husband, Payload Specialist Ilan Ramon, of Israel, and Payload Commander Michael P. Anderson. A trainer is at far right. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. The CEIT activities enable the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. Other STS-107 crew members are Pilot William C. McCool and Mission Specialists Kalpana Chawla and David M. Brown. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- STS-107 Payload Specialist Ilan Ramon, of Israel, manipulates a piece of equipment in the Spacehab module. He and other crew members are taking part in Crew Equipment Interface Test (CEIT) activities at SPACEHAB, Cape Canaveral, Fla. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. The CEIT activities enable the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. Other STS-107 crew members are Commander Rick Douglas Husband, Pilot William C. McCool; Payload Commander Michael P. Anderson; and Mission Specialists Kalpana Chawla, Laurel Blair Salton Clark and David M. Brown. STS-107 is scheduled for launch May 23, 2002

Design and test of data acquisition systems for the Medipix2 chip based on PC standard interfaces

NASA Astrophysics Data System (ADS)

Fanti, Viviana; Marzeddu, Roberto; Piredda, Giuseppina; Randaccio, Paolo

2005-07-01

We describe two readout systems for hybrid detectors using the Medipix2 single photon counting chip, developed within the Medipix Collaboration. The Medipix2 chip (256×256 pixels, 55 μm pitch) has an active area of about 2 cm 2 and is bump-bonded to a pixel semiconductor array of silicon or other semiconductor material. The readout systems we are developing are based on two widespread standard PC interfaces: parallel port and USB (Universal Serial Bus) version 1.1. The parallel port is the simplest PC interface even if slow and the USB is a serial bus interface present nowadays on all PCs and offering good performances.

Novel fabrication method for 3D microstructures using surface-activated bonding and its application to micro-mechanical parts

NASA Astrophysics Data System (ADS)

Yamada, Takayuki; Takahashi, Mutsuya; Ozawa, Takashi; Tawara, Satoshi; Goto, Takayuki

2002-11-01

The purpose of this work is to demonstrate that a novel fabrication method for 3-D microstructures (FORMULA) is applicable to fabrication of micro mechanical parts with a large flexibility. This method is a kind of layer manufacturing method of thin films for metallic or dielectric microstructures using surface-activated bonding (SAB). The bonding interfaces of thin films are investigated by transmission electron microscope (TEM). Voids were observed at the interfaces of both pure aluminum films and Al-Cu alloy films. The ratio of void on the Al-Cu/Al-Cu interface is much larger than that of Al/Al interface, although the films have the same surface roughness of 3nm in Ra (average roughness). And approximately 10nm-thick amorphous intermediate layers were found at the interfaces. Furthermore, we have fabricated a micro gear of 900μm in diameter and 200μm in height, which is about ten times as large as our previous test pieces. Overhung structures such as a bridge structure and a cantilever were also fabricated without supporting layers beneath them.

User-centered development and testing of a monitoring system that provides feedback regarding physical functioning to elderly people

PubMed Central

Vermeulen, Joan; Neyens, Jacques CL; Spreeuwenberg, Marieke D; van Rossum, Erik; Sipers, Walther; Habets, Herbert; Hewson, David J; de Witte, Luc P

2013-01-01

Purpose To involve elderly people during the development of a mobile interface of a monitoring system that provides feedback to them regarding changes in physical functioning and to test the system in a pilot study. Methods and participants The iterative user-centered development process consisted of the following phases: (1) selection of user representatives; (2) analysis of users and their context; (3) identification of user requirements; (4) development of the interface; and (5) evaluation of the interface in the lab. Subsequently, the monitoring and feedback system was tested in a pilot study by five patients who were recruited via a geriatric outpatient clinic. Participants used a bathroom scale to monitor weight and balance, and a mobile phone to monitor physical activity on a daily basis for six weeks. Personalized feedback was provided via the interface of the mobile phone. Usability was evaluated on a scale from 1 to 7 using a modified version of the Post-Study System Usability Questionnaire (PSSUQ); higher scores indicated better usability. Interviews were conducted to gain insight into the experiences of the participants with the system. Results The developed interface uses colors, emoticons, and written and/or spoken text messages to provide daily feedback regarding (changes in) weight, balance, and physical activity. The participants rated the usability of the monitoring and feedback system with a mean score of 5.2 (standard deviation 0.90) on the modified PSSUQ. The interviews revealed that most participants liked using the system and appreciated that it signaled changes in their physical functioning. However, usability was negatively influenced by a few technical errors. Conclusion Involvement of elderly users during the development process resulted in an interface with good usability. However, the technical functioning of the monitoring system needs to be optimized before it can be used to support elderly people in their self-management. PMID:24039407

Open ISEmeter: An open hardware high-impedance interface for potentiometric detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salvador, C.; Carbajo, J.; Mozo, J. D., E-mail: jdaniel.mozo@diq.uhu.es

In this work, a new open hardware interface based on Arduino to read electromotive force (emf) from potentiometric detectors is presented. The interface has been fully designed with the open code philosophy and all documentation will be accessible on web. The paper describes a comprehensive project including the electronic design, the firmware loaded on Arduino, and the Java-coded graphical user interface to load data in a computer (PC or Mac) for processing. The prototype was tested by measuring the calibration curve of a detector. As detection element, an active poly(vinyl chloride)-based membrane was used, doped with cetyltrimethylammonium dodecylsulphate (CTA{sup +}-DS{supmore » −}). The experimental measures of emf indicate Nernstian behaviour with the CTA{sup +} content of test solutions, as it was described in the literature, proving the validity of the developed prototype. A comparative analysis of performance was made by using the same chemical detector but changing the measurement instrumentation.« less

Systems test facilities existing capabilities compilation

NASA Technical Reports Server (NTRS)

Weaver, R.

1981-01-01

Systems test facilities (STFS) to test total photovoltaic systems and their interfaces are described. The systems development (SD) plan is compilation of existing and planned STFs, as well as subsystem and key component testing facilities. It is recommended that the existing capabilities compilation is annually updated to provide and assessment of the STF activity and to disseminate STF capabilities, status and availability to the photovoltaics program.

Time-recovering PCI-AER interface for bio-inspired spiking systems

NASA Astrophysics Data System (ADS)

Paz-Vicente, R.; Linares-Barranco, A.; Cascado, D.; Vicente, S.; Jimenez, G.; Civit, A.

2005-06-01

Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows for real-time virtual massive connectivity between huge number neurons located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate 'events' according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. When building multi-chip muti-layered AER systems it is absolutely necessary to have a computer interface that allows (a) to read AER interchip traffic into the computer and visualize it on screen, and (b) inject a sequence of events at some point of the AER structure. This is necessary for testing and debugging complex AER systems. This paper presents a PCI to AER interface, that dispatches a sequence of events received from the PCI bus with embedded timing information to establish when each event will be delivered. A set of specialized states machines has been introduced to recovery the possible time delays introduced by the asynchronous AER bus. On the input channel, the interface capture events assigning a timestamp and delivers them through the PCI bus to MATLAB applications. It has been implemented in real time hardware using VHDL and it has been tested in a PCI-AER board, developed by authors, that includes a Spartan II 200 FPGA. The demonstration hardware is currently capable to send and receive events at a peak rate of 8,3 Mev/sec, and a typical rate of 1 Mev/sec.

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- STS-107 Payload Commander Michael Anderson trains on equipment in the training module at SPACEHAB, Cape Canaveral, Fla. Anderson and other crew members Commander Rick D. Husband, Pilot William C. McCool, Mission Specialists Kalpana Chawla, Laurel Blair Salton Clark and David M. Brown; and Payload Specialist Ilan Ramon, of Israel, are at SPACEHAB to take part in Crew Equipment Interface Test (CEIT) activities. The CEIT enables the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. . As a research mission, STS-107 will carry the SPACEHAB Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- STS-107 Mission Specialist David M. Brown trains on equipment in the training module at SPACEHAB, Cape Canaveral, Fla. Brown and other crew members Commander Rick D. Husband, Pilot William C. McCool, Payload Commander Michael P. Anderson; Mission Specialists Kalpana Chawla and Laurel Blair Salton Clark; and Payload Specialist Ilan Ramon, of Israel, are at SPACEHAB to take part in Crew Equipment Interface Test (CEIT) activities. The CEIT enables the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. As a research mission, STS-107 will carry the SPACEHAB Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- STS-107 Payload Specialist Ilan Ramon, of Israel, trains on equipment in the training module at SPACEHAB, Cape Canaveral. Ramon and other crew members Commander Rick D. Husband, Pilot William C. McCool, Payload Commander Michael P. Anderson; and Mission Specialists Kalpana Chawla, Laurel Blair Salton Clark and David M. Brown are at SPACEHAB to take part in Crew Equipment Interface Test (CEIT) activities. The CEIT enables the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. As a research mission, STS-107 will carry the SPACEHAB Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- At SPACEHAB, Cape Canaveral, Fla., STS-107 Mission Specialist Laurel Blair Salton Clark manipulates a piece of equipment. She and other crew members are at SPACEHAB, Port Canaveral, Fla., for Crew Equipment Interface Test (CEIT) activities that enable the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. Other STS-107 crew members are Commander Rick Douglas Husband, Pilot William C. McCool; Payload Commander Michael P. Anderson; and Mission Specialists Kalpana Chawla, David M. Brown and Ilan Ramon, of Israel. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- At SPACEHAB, Cape Canaveral, Fla., Mission Specialist Laurel Blair Salton Clark practices an experiment while Commander Rick Douglas Husband and Mission Specialist Kalpana Chawla observe. They and other crew members Pilot William C. McCool; Payload Commander Michael P. Anderson; and Mission Specialists David M. Brown and Ilan Ramon, of Israel, are at SPACEHAB for Crew Equipment Interface Test (CEIT) activities. The CEIT enables the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. STS-107 is scheduled for launch May 23, 2002

[Comparison between lymphocytic infiltration in early spontaneous abortions and in elective abortions with signs of disruption at the chorio-decidual interface].

PubMed

Caliendo, L

2007-12-01

The aim of the study was to compare lymphocytic infiltrations in early spontaneous abortions with those with signs of disruption at the chorio-decidual interface in elective abortions. Determinations were performed on preparations received at the Anatomy-Pathology Services of Ospedale San Paolo, Savona (Italy) in 2005. Immunohistochemistry studies were performed using antisera CD3, CD4 and CD14 with a DAB detection kit on a Ventana BenchMark automated slide staining system. The material was grouped into three classes: early spontaneous abortions (class 1); elective abortions with signs of disruption at the chorio-decidual interface (class 2); elective abortions without such signs (class 3). Preparations from classes 1 and 2 shared a similar picture of lymphocytic activation and the presence of macrophagic elements. The test results demonstrated that the proportion of the T cell population increased with the rise in CD8+ lymphocytes in both class 1 and class 2 preparations. The results indicate that T-cell-mediated immune activation may the cause or one of the causes of spontaneous abortion and that the effects of disruption at the chorio-decidual interface observed in elective abortion provide a clue to initial signs of loss of pregnancy. From the discovery of a population without evident signs of active abortion (elective abortion with a disturbed chorio-decidual interface) but with evidence of initial lymphocytic activation compared with that devoid of such signs (elective abortion) one can conjecture that lymphocytic activation is a major factor in the process leading to early spontaneous abortion.

The antimalarial activity of Ru–chloroquine complexes against resistant Plasmodium falciparum is related to lipophilicity, basicity, and heme aggregation inhibition ability near water/n-octanol interfaces

PubMed Central

Martínez, Alberto; Rajapakse, Chandima S. K.; Jalloh, Dalanda; Dautriche, Cula

2012-01-01

We have measured water/n-octanol partition coefficients, pKa values, heme binding constants, and heme aggregation inhibition activity of a series of ruthenium–πarene–chloroquine (CQ) complexes recently reported to be active against CQ-resistant strains of Plasmodium falciparum. Measurements of heme aggregation inhibition activity of the metal complexes near water/n-octanol interfaces qualitatively predict their superior antiplasmodial action against resistant parasites, in relation to CQ; we conclude that this modified method may be a better predictor of antimalarial potency than standard tests in aqueous acidic buffer. Some interesting tendencies emerge from our data, indicating that the antiplasmodial activity is related to a balance of effects associated with the lipophilicity, basicity, and structural details of the compounds studied. PMID:19343380

The antimalarial activity of Ru-chloroquine complexes against resistant Plasmodium falciparum is related to lipophilicity, basicity, and heme aggregation inhibition ability near water/n-octanol interfaces.

PubMed

Martínez, Alberto; Rajapakse, Chandima S K; Jalloh, Dalanda; Dautriche, Cula; Sánchez-Delgado, Roberto A

2009-08-01

We have measured water/n-octanol partition coefficients, pK(a) values, heme binding constants, and heme aggregation inhibition activity of a series of ruthenium-pi-arene-chloroquine (CQ) complexes recently reported to be active against CQ-resistant strains of Plasmodium falciparum. Measurements of heme aggregation inhibition activity of the metal complexes near water/n-octanol interfaces qualitatively predict their superior antiplasmodial action against resistant parasites, in relation to CQ; we conclude that this modified method may be a better predictor of antimalarial potency than standard tests in aqueous acidic buffer. Some interesting tendencies emerge from our data, indicating that the antiplasmodial activity is related to a balance of effects associated with the lipophilicity, basicity, and structural details of the compounds studied.

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- At SPACEHAB, Cape Canaveral, Fla., STS-107 Mission Specialist Kalpana Chawla checks out items stored in the Spacehab module. Behind her, left, is Payload Specialist Ilan Ramon, of Israel, looking over a piece of equipment. At right is a trainer. The crew is taking part in Crew Equipment Interface Test (CEIT) activities at SPACEHAB, Port Canaveral, Fla. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. The CEIT activities enable the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. Other STS-107 crew members are Commander Rick Douglas Husband, Pilot William C. McCool; Payload Commander Michael P. Anderson; and Mission Specialists Laurel Blair Salton Clark and David M. Brown. STS-107 is scheduled for launch May 23, 2002

Evaluation of an active seating system for pressure relief.

PubMed

Koo, T K; Mak, A F; Lee, Y L

1995-01-01

In the first part of this study, the inflation-pressure and interface-pressure profiles of an active cushion system, the Talley active air bellows cushion, were examined continuously for one complete working cycle using the dynamic pressure monitor. The relationship between the inflation pressure and the interface pressure was explored. A well-defined relationship was found in the areas directly over the air bellows. In the second part of this study, the pressure-relieving characteristics of the active cushion were assessed quantitatively and compared to two types of passive cushions--the Roho high-profile air floatation cushion and the polyurethane (PU) foam cushion. Eight non-disabled subjects were positioned on the active cushion at two inflation-pressure levels--30 mmHg and 60 mmHg, or on the Roho or the PU foam cushions. Interface pressures were recorded using the Oxford pressure monitor. For the active cushion it was shown that the higher the inflation pressure was, the better the pressure-relieving characteristics seemed to be. In general, the pressure-relieving characteristics of the active cushion were not as good as those of the passive cushions being tested. The active cushion could alter the pressures over the ischial tuberosities cyclically but the amount of pressure alternation depended on the relative position of the ischial tuberosities and the air bellows.

Role of large-scale slip in mode II fracture of bimaterial interface produced by diffusion bonding

NASA Astrophysics Data System (ADS)

Fox, M. R.; Ghosh, A. K.

2001-08-01

Bimaterial interfaces present in diffusion-bonded (and in-situ) composites are often not flat interfaces. The unevenness of the interface can result not only from interface reaction products but also from long-range waviness associated with the surfaces of the component phases bonded together. Experimental studies aimed at determining interface mechanical properties generally ignore the departure in the local stress due to waviness and assume a theoretically flat interface. Furthermore, the commonly used testing methods involving superimposed tension often renders the interface so extremely brittle that if microplastic effects were present it becomes impossible to perceive them. This article examines the role of waviness of the interface and microplastic effects on crack initiation. To do this, a test was selected that provides significant stability against crack growth by superimposing compressive stresses. Mode II interface fracture was studied for NiAl/Mo model laminates using a recently developed asymmetrically loaded shear (ALS) interface shear test. The ALS test may be viewed as opposite of the laminate bend test. In the bend test, shear at the interface is created via tension on one surface of the bend, while in the ALS test, shear is created by compression on one side of the interface relative to the other. Normal to the interface, near the crack tip, an initially compressive state is replaced by slight tension due to Poisson’s expansion of the unbonded part of the compressed beam.

Human computer interface guide, revision A

NASA Technical Reports Server (NTRS)

1993-01-01

The Human Computer Interface Guide, SSP 30540, is a reference document for the information systems within the Space Station Freedom Program (SSFP). The Human Computer Interface Guide (HCIG) provides guidelines for the design of computer software that affects human performance, specifically, the human-computer interface. This document contains an introduction and subparagraphs on SSFP computer systems, users, and tasks; guidelines for interactions between users and the SSFP computer systems; human factors evaluation and testing of the user interface system; and example specifications. The contents of this document are intended to be consistent with the tasks and products to be prepared by NASA Work Package Centers and SSFP participants as defined in SSP 30000, Space Station Program Definition and Requirements Document. The Human Computer Interface Guide shall be implemented on all new SSFP contractual and internal activities and shall be included in any existing contracts through contract changes. This document is under the control of the Space Station Control Board, and any changes or revisions will be approved by the deputy director.

Spacelab interface development test, volume 1, sections 1-6

NASA Technical Reports Server (NTRS)

Harris, L. H.

1979-01-01

Data recorded during the following tests is presented: pulse coded modulator master unit to Spacelab (S/L) interface, master timing unit to S/L interface, multiplexer-demultiplexer/serial input-output to S/L interface, and special tests.

Electro-Active Polymer Based Soft Tactile Interface for Wearable Devices.

PubMed

Mun, Seongcheol; Yun, Sungryul; Nam, Saekwang; Park, Seung Koo; Park, Suntak; Park, Bong Je; Lim, Jeong Mook; Kyung, Ki-Uk

2018-01-01

This paper reports soft actuator based tactile stimulation interfaces applicable to wearable devices. The soft actuator is prepared by multi-layered accumulation of thin electro-active polymer (EAP) films. The multi-layered actuator is designed to produce electrically-induced convex protrusive deformation, which can be dynamically programmable for wide range of tactile stimuli. The maximum vertical protrusion is and the output force is up to 255 mN. The soft actuators are embedded into the fingertip part of a glove and front part of a forearm band, respectively. We have conducted two kinds of experiments with 15 subjects. Perceived magnitudes of actuator's protrusion and vibrotactile intensity were measured with frequency of 1 Hz and 191 Hz, respectively. Analysis of the user tests shows participants perceive variation of protrusion height at the finger pad and modulation of vibration intensity through the proposed soft actuator based tactile interface.

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- STS-107 Commander Rick D. Husband (left) and Pilot William C. McCool train in the SPACHEAB Double Module that will fly on their mission. Husband, McCool and other crew members Payload Commander Michael P. Anderson; Mission Specialists Laurel Blair Salton Clark and David M. Brown; and Payload Specialist Ilan Ramon, of Israel, are at SPACEHAB, Cape Canaveral, Fla., to take part in Crew Equipment Interface Test (CEIT) activities. The CEIT enables the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. As a research mission, STS-107 will carry the SPACEHAB Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- At SPACEHAB, Cape Canaveral, Fla., members of the STS-107 crew discuss the experiments in the Spacehab module. Seated, in the foreground, is Mission Specialist Laurel Blair Salton Clark; standing behind her are Commander Rick Douglas Husband and Mission Specialist Kalpana Chawla. They and other crew members Pilot William C. McCool; Payload Commander Michael P. Anderson; and Mission Specialists David M. Brown and Ilan Ramon, of Israel, are at SPACEHAB for Crew Equipment Interface Test (CEIT) activities. The CEIT enables the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. STS-107 is scheduled for launch May 23, 2002

STS-107 Crew Equipment Interface Test (CEIT)activities at SPACEHAB

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- At SPACEHAB, Cape Canaveral, Fla., STS-107 Payload Specialist Ilan Ramon (foreground), of Israel, and Mission Specialist Kalpana Chawla (background) check out experiments inside the Spacehab module. They and other crew members are taking part in Crew Equipment Interface Test (CEIT) activities that enable the crew to perform certain flight operations, operate experiments in a flight-like environment, evaluate stowage locations and obtain additional exposure to specific experiment operations. As a research mission, STS-107 will carry the Spacehab Double Module in its first research flight into space and a broad collection of experiments ranging from material science to life science. . Other STS-107 crew members are Commander Rick Douglas Husband, Pilot William C. McCool; Payload Commander Michael P. Anderson; and Mission Specialists Laurel Blair Salton Clark and David M. Brown. STS-107 is scheduled for launch May 23, 2002

A Frequency-Domain Substructure System Identification Algorithm

NASA Technical Reports Server (NTRS)

Blades, Eric L.; Craig, Roy R., Jr.

1996-01-01

A new frequency-domain system identification algorithm is presented for system identification of substructures, such as payloads to be flown aboard the Space Shuttle. In the vibration test, all interface degrees of freedom where the substructure is connected to the carrier structure are either subjected to active excitation or are supported by a test stand with the reaction forces measured. The measured frequency-response data is used to obtain a linear, viscous-damped model with all interface-degree of freedom entries included. This model can then be used to validate analytical substructure models. This procedure makes it possible to obtain not only the fixed-interface modal data associated with a Craig-Bampton substructure model, but also the data associated with constraint modes. With this proposed algorithm, multiple-boundary-condition tests are not required, and test-stand dynamics is accounted for without requiring a separate modal test or finite element modeling of the test stand. Numerical simulations are used in examining the algorithm's ability to estimate valid reduced-order structural models. The algorithm's performance when frequency-response data covering narrow and broad frequency bandwidths is used as input is explored. Its performance when noise is added to the frequency-response data and the use of different least squares solution techniques are also examined. The identified reduced-order models are also compared for accuracy with other test-analysis models and a formulation for a Craig-Bampton test-analysis model is also presented.

Adaptive Offset Correction for Intracortical Brain Computer Interfaces

PubMed Central

Homer, Mark L.; Perge, János A.; Black, Michael J.; Harrison, Matthew T.; Cash, Sydney S.; Hochberg, Leigh R.

2014-01-01

Intracortical brain computer interfaces (iBCIs) decode intended movement from neural activity for the control of external devices such as a robotic arm. Standard approaches include a calibration phase to estimate decoding parameters. During iBCI operation, the statistical properties of the neural activity can depart from those observed during calibration, sometimes hindering a user’s ability to control the iBCI. To address this problem, we adaptively correct the offset terms within a Kalman filter decoder via penalized maximum likelihood estimation. The approach can handle rapid shifts in neural signal behavior (on the order of seconds) and requires no knowledge of the intended movement. The algorithm, called MOCA, was tested using simulated neural activity and evaluated retrospectively using data collected from two people with tetraplegia operating an iBCI. In 19 clinical research test cases, where a nonadaptive Kalman filter yielded relatively high decoding errors, MOCA significantly reduced these errors (10.6 ±10.1%; p<0.05, pairwise t-test). MOCA did not significantly change the error in the remaining 23 cases where a nonadaptive Kalman filter already performed well. These results suggest that MOCA provides more robust decoding than the standard Kalman filter for iBCIs. PMID:24196868

Adaptive offset correction for intracortical brain-computer interfaces.

PubMed

Homer, Mark L; Perge, Janos A; Black, Michael J; Harrison, Matthew T; Cash, Sydney S; Hochberg, Leigh R

2014-03-01

Intracortical brain-computer interfaces (iBCIs) decode intended movement from neural activity for the control of external devices such as a robotic arm. Standard approaches include a calibration phase to estimate decoding parameters. During iBCI operation, the statistical properties of the neural activity can depart from those observed during calibration, sometimes hindering a user's ability to control the iBCI. To address this problem, we adaptively correct the offset terms within a Kalman filter decoder via penalized maximum likelihood estimation. The approach can handle rapid shifts in neural signal behavior (on the order of seconds) and requires no knowledge of the intended movement. The algorithm, called multiple offset correction algorithm (MOCA), was tested using simulated neural activity and evaluated retrospectively using data collected from two people with tetraplegia operating an iBCI. In 19 clinical research test cases, where a nonadaptive Kalman filter yielded relatively high decoding errors, MOCA significantly reduced these errors ( 10.6 ± 10.1% ; p < 0.05, pairwise t-test). MOCA did not significantly change the error in the remaining 23 cases where a nonadaptive Kalman filter already performed well. These results suggest that MOCA provides more robust decoding than the standard Kalman filter for iBCIs.

The source of high signal cooperativity in bacterial chemosensory arrays

PubMed Central

Piñas, Germán E.; Frank, Vered; Vaknin, Ady; Parkinson, John S.

2016-01-01

The Escherichia coli chemosensory system consists of large arrays of transmembrane chemoreceptors associated with a dedicated histidine kinase, CheA, and a linker protein, CheW, that couples CheA activity to receptor control. The kinase activity responses to receptor ligand occupancy changes can be highly cooperative, reflecting allosteric coupling of multiple CheA and receptor molecules. Recent structural and functional studies have led to a working model in which receptor core complexes, the minimal units of signaling, are linked into hexagonal arrays through a unique interface 2 interaction between CheW and the P5 domain of CheA. To test this array model, we constructed and characterized CheA and CheW mutants with amino acid replacements at key interface 2 residues. The mutant proteins proved defective in interface 2-specific in vivo cross-linking assays, and formed signaling complexes that were dispersed around the cell membrane rather than clustered at the cell poles as in wild type chemosensory arrays. Interface 2 mutants down-regulated CheA activity in response to attractant stimuli in vivo, but with much less cooperativity than the wild type. Moreover, mutant cells containing fluorophore-tagged receptors exhibited greater basal anisotropy that changed rapidly in response to attractant stimuli, consistent with facile changes in loosely packed receptors. We conclude that interface 2 lesions disrupt important network connections between core complexes, preventing receptors from operating in large, allosteric teams. This work confirms the critical role of interface 2 in organizing the chemosensory array, in directing the clustered array to the cell poles, and in producing its highly cooperative signaling properties. PMID:26951681

Glove-Enabled Computer Operations (GECO): Design and Testing of an Extravehicular Activity Glove Adapted for Human-Computer Interface

NASA Technical Reports Server (NTRS)

Adams, Richard J.; Olowin, Aaron; Krepkovich, Eileen; Hannaford, Blake; Lindsay, Jack I. C.; Homer, Peter; Patrie, James T.; Sands, O. Scott

2013-01-01

The Glove-Enabled Computer Operations (GECO) system enables an extravehicular activity (EVA) glove to be dual-purposed as a human-computer interface device. This paper describes the design and human participant testing of a right-handed GECO glove in a pressurized glove box. As part of an investigation into the usability of the GECO system for EVA data entry, twenty participants were asked to complete activities including (1) a Simon Says Games in which they attempted to duplicate random sequences of targeted finger strikes and (2) a Text Entry activity in which they used the GECO glove to enter target phrases in two different virtual keyboard modes. In a within-subjects design, both activities were performed both with and without vibrotactile feedback. Participants' mean accuracies in correctly generating finger strikes with the pressurized glove were surprisingly high, both with and without the benefit of tactile feedback. Five of the subjects achieved mean accuracies exceeding 99% in both conditions. In Text Entry, tactile feedback provided a statistically significant performance benefit, quantified by characters entered per minute, as well as reduction in error rate. Secondary analyses of responses to a NASA Task Loader Index (TLX) subjective workload assessments reveal a benefit for tactile feedback in GECO glove use for data entry. This first-ever investigation of employment of a pressurized EVA glove for human-computer interface opens up a wide range of future applications, including text "chat" communications, manipulation of procedures/checklists, cataloguing/annotating images, scientific note taking, human-robot interaction, and control of suit and/or other EVA systems.

Glove-Enabled Computer Operations (GECO): Design and Testing of an Extravehicular Activity Glove Adapted for Human-Computer Interface

NASA Technical Reports Server (NTRS)

Adams, Richard J.; Olowin, Aaron; Krepkovich, Eileen; Hannaford, Blake; Lindsay, Jack I. C.; Homer, Peter; Patrie, James T.; Sands, O. Scott

2013-01-01

The Glove-Enabled Computer Operations (GECO) system enables an extravehicular activity (EVA) glove to be dual-purposed as a human-computer interface device. This paper describes the design and human participant testing of a right-handed GECO glove in a pressurized glove box. As part of an investigation into the usability of the GECO system for EVA data entry, twenty participants were asked to complete activities including (1) a Simon Says Games in which they attempted to duplicate random sequences of targeted finger strikes and (2) a Text Entry activity in which they used the GECO glove to enter target phrases in two different virtual keyboard modes. In a within-subjects design, both activities were performed both with and without vibrotactile feedback. Participants mean accuracies in correctly generating finger strikes with the pressurized glove were surprisingly high, both with and without the benefit of tactile feedback. Five of the subjects achieved mean accuracies exceeding 99 in both conditions. In Text Entry, tactile feedback provided a statistically significant performance benefit, quantified by characters entered per minute, as well as reduction in error rate. Secondary analyses of responses to a NASA Task Loader Index (TLX) subjective workload assessments reveal a benefit for tactile feedback in GECO glove use for data entry. This first-ever investigation of employment of a pressurized EVA glove for human-computer interface opens up a wide range of future applications, including text chat communications, manipulation of procedureschecklists, cataloguingannotating images, scientific note taking, human-robot interaction, and control of suit andor other EVA systems.

PDSS configuration control plan and procedures

NASA Technical Reports Server (NTRS)

1983-01-01

The payload development support system (PDSS) configuration control plan and procedures are presented. These plans and procedures establish the process for maintaining configuration control of the PDSS system, especially the Spacelab experiment interface device's (SEID) RAU, HRM, and PDI interface simulations and the PDSS ECOS DEP Services simulation. The plans and procedures as specified are designed to provide a simplified but complete configuration control process. The intent is to require a minimum amount of paperwork but provide total traceability of PDSS during experiment test activities.

Pratt and Whitney Overview and Advanced Health Management Program

NASA Technical Reports Server (NTRS)

Inabinett, Calvin

2008-01-01

Hardware Development Activity: Design and Test Custom Multi-layer Circuit Boards for use in the Fault Emulation Unit; Logic design performed using VHDL; Layout power system for lab hardware; Work lab issues with software developers and software testers; Interface with Engine Systems personnel with performance of Engine hardware components; Perform off nominal testing with new engine hardware.

Silicon-based products and solutions

NASA Astrophysics Data System (ADS)

Painchaud, Y.; Poulin, M.; Pelletier, F.; Latrasse, C.; Gagné, J.-F.; Savard, S.; Robidoux, G.; Picard, M.-.; Paquet, S.; Davidson, C.-.; Pelletier, M.; Cyr, M.; Paquet, C.; Guy, M.; Morsy-Osman, M.; Chagnon, M.; Plant, D. V.

2014-03-01

TeraXion started silicon photonics activities aiming at developing building blocks for new products and customized solutions. Passive and active devices have been developed including MMI couplers, power splitters, Bragg grating filters, high responsivity photodetectors, high speed modulators and variable optical attenuators. Packaging solutions including fiber attachment and hybrid integration using flip-chip were also developed. More specifically, a compact packaged integrated coherent receiver has been realized. Good performances were obtained as demonstrated by our system tests results showing transmission up to 4800 km with BER below hard FEC threshold. The package size is small but still limited by the electrical interface. Migrating to more compact RF interface would allow realizing the full benefit of this technology.

A hybrid brain-computer interface-based mail client.

PubMed

Yu, Tianyou; Li, Yuanqing; Long, Jinyi; Li, Feng

2013-01-01

Brain-computer interface-based communication plays an important role in brain-computer interface (BCI) applications; electronic mail is one of the most common communication tools. In this study, we propose a hybrid BCI-based mail client that implements electronic mail communication by means of real-time classification of multimodal features extracted from scalp electroencephalography (EEG). With this BCI mail client, users can receive, read, write, and attach files to their mail. Using a BCI mouse that utilizes hybrid brain signals, that is, motor imagery and P300 potential, the user can select and activate the function keys and links on the mail client graphical user interface (GUI). An adaptive P300 speller is employed for text input. The system has been tested with 6 subjects, and the experimental results validate the efficacy of the proposed method.

A Hybrid Brain-Computer Interface-Based Mail Client

PubMed Central

Yu, Tianyou; Li, Yuanqing; Long, Jinyi; Li, Feng

2013-01-01

Brain-computer interface-based communication plays an important role in brain-computer interface (BCI) applications; electronic mail is one of the most common communication tools. In this study, we propose a hybrid BCI-based mail client that implements electronic mail communication by means of real-time classification of multimodal features extracted from scalp electroencephalography (EEG). With this BCI mail client, users can receive, read, write, and attach files to their mail. Using a BCI mouse that utilizes hybrid brain signals, that is, motor imagery and P300 potential, the user can select and activate the function keys and links on the mail client graphical user interface (GUI). An adaptive P300 speller is employed for text input. The system has been tested with 6 subjects, and the experimental results validate the efficacy of the proposed method. PMID:23690880

Development of CO2 laser Doppler instrumentation for detection of clear air turbulence, volume 1

NASA Technical Reports Server (NTRS)

Harris, C. E.; Jelalian, A. V.

1979-01-01

Modification, construction, test and operation of an advanced airborne carbon dioxide laser Doppler system for detecting clear air turbulence are described. The second generation CAT program and those auxiliary activities required to support and verify such a first-of-a-kind system are detailed: aircraft interface; ground and flight verification tests; data analysis; and laboratory examinations.

Triphasic scaffolds for the regeneration of the bone-ligament interface.

PubMed

Criscenti, G; Longoni, A; Di Luca, A; De Maria, C; van Blitterswijk, C A; Vozzi, G; Moroni, L

2016-01-29

A triphasic scaffold (TPS) for the regeneration of the bone-ligament interface was fabricated combining a 3D fiber deposited polycaprolactone structure and a polylactic co-glycolic acid electrospun. The scaffold presented a gradient of physical and mechanical properties which elicited different biological responses from human mesenchymal stem cells. Biological test were performed on the whole TPS and on scaffolds comprised of each single part of the TPS, considered as the controls. The TPS showed an increase of the metabolic activity with culturing time that seemed to be an average of the controls at each time point. The importance of differentiation media for bone and ligament regeneration was further investigated. Metabolic activity analysis on the different areas of the TPS showed a similar trend after 7 days in both differentiation media. Total alkaline phosphatase (ALP) activity analysis showed a statistically higher activity of the TPS in mineralization medium compared to the controls. A different glycosaminoglycans amount between the TPS and its controls was detected, displaying a similar trend with respect to ALP activity. Results clearly indicated that the integration of electrospinning and additive manufacturing represents a promising approach for the fabrication of scaffolds for the regeneration of tissue interfaces, such as the bone-to-ligament one, because it allows mimicking the structural environment combining different biomaterials at different scales.

A direct-interface fusible heat sink for astronaut cooling

NASA Technical Reports Server (NTRS)

Lomax, Curtis; Webbon, B. W.

1990-01-01

Astronaut cooling during extravehicular activity is a critical design issue in developing a portable life support system that meets the requirements of a space station mission. Some the requirements are that the cooling device can be easily regenerable and nonventing during operation. In response to this, a direct-interface, fusible heat sink prototpye with freezable quick-disconnects was developed. A proof-of-concept prototype was constructed and tested that consists of an elastic container filled with normal tap water and having two quick-disconnects embedded in a wall. These quick-disconnects are designed so that they may be frozen with the ice and yet still be joined to the cooling system, allowing an immediate flow path. The inherent difficulties in a direct-interface heat sink have been overcome, i.e., (1) establishing an initial flow path; (2) avoiding low-flow freeze-up; and (3) achieving adequate heat-transfer rates at the end of the melting process. The requirements, design, fabrication, and testing are discussed.

A direct-interface, fusible heat sink for astronaut cooling

NASA Technical Reports Server (NTRS)

Lomax, Curtis; Webbon, B. W.

1990-01-01

Astronaut cooling during extravehicular activity is a critical design issue in developing a portable life support system that meets the requirements of a space station mission. Some of the requirements are that the cooling device can be easily regenerable and nonventing during operation. In response to this, a direct-interface, fusible heat sink prototype with freezable quick-disconnects was developed. A proof-of-concept prototype was constructed and tested that consists of an elastic container filled with normal tap water and having two quick-disconnects embedded in a wall. These quick-disconnects are designed so that they may be frozen with the ice and yet still be joined to the cooling system, allowing an immediate flow path. The inherent difficulties in a direct-interface heat sink have been overcome, i.e., (1) establishing an initial flow path; (2) avoiding low-flow freeze-up; and (3) achieving adequate heat-transfer rates at the end of the melting process. The requirements, design, fabrication, and testing are discussed.

The STS-108 crew look over MPLM during Crew Equipment Interface Test

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- The STS-108 crew look into the hatch of the Multi-Purpose Logistics Module Raffaello. From left are Commander Dominic L. Gorie, Pilot Mark E. Kelly, and Mission Specialists Linda A. Godwin and Daniel M. Tani. The four astronauts are taking part in Crew Equipment Interface Test (CEIT) activities at KSC. The CEIT provides familiarization with the launch vehicle and payload. Mission STS-108 is a Utilization Flight (UF-1), carrying the Expedition Four crew plus Multi-Purpose Logistics Module Raffaello to the International Space Station. The Expedition Four crew comprises Yuri Onufriyenko, commander, Russian Aviation and Space Agency, and astronauts Daniel W. Bursch and Carl E. Walz. Endeavour is scheduled to launch Nov. 29 on mission STS-108.

An adaptive brain actuated system for augmenting rehabilitation

PubMed Central

Roset, Scott A.; Gant, Katie; Prasad, Abhishek; Sanchez, Justin C.

2014-01-01

For people living with paralysis, restoration of hand function remains the top priority because it leads to independence and improvement in quality of life. In approaches to restore hand and arm function, a goal is to better engage voluntary control and counteract maladaptive brain reorganization that results from non-use. Standard rehabilitation augmented with developments from the study of brain-computer interfaces could provide a combined therapy approach for motor cortex rehabilitation and to alleviate motor impairments. In this paper, an adaptive brain-computer interface system intended for application to control a functional electrical stimulation (FES) device is developed as an experimental test bed for augmenting rehabilitation with a brain-computer interface. The system's performance is improved throughout rehabilitation by passive user feedback and reinforcement learning. By continuously adapting to the user's brain activity, similar adaptive systems could be used to support clinical brain-computer interface neurorehabilitation over multiple days. PMID:25565945

ARX - A Comprehensive Tool for Anonymizing Biomedical Data

PubMed Central

Prasser, Fabian; Kohlmayer, Florian; Lautenschläger, Ronald; Kuhn, Klaus A.

2014-01-01

Collaboration and data sharing have become core elements of biomedical research. Especially when sensitive data from distributed sources are linked, privacy threats have to be considered. Statistical disclosure control allows the protection of sensitive data by introducing fuzziness. Reduction of data quality, however, needs to be balanced against gains in protection. Therefore, tools are needed which provide a good overview of the anonymization process to those responsible for data sharing. These tools require graphical interfaces and the use of intuitive and replicable methods. In addition, extensive testing, documentation and openness to reviews by the community are important. Existing publicly available software is limited in functionality, and often active support is lacking. We present ARX, an anonymization tool that i) implements a wide variety of privacy methods in a highly efficient manner, ii) provides an intuitive cross-platform graphical interface, iii) offers a programming interface for integration into other software systems, and iv) is well documented and actively supported. PMID:25954407

Microstructural and Mechanical Evaluation of a Cu-Based Active Braze Alloy to Join Silicon Nitride Ceramics

NASA Technical Reports Server (NTRS)

Singh, M.; Asthana, Rajiv; Varela, F. M.; Martinez-Fernandez, J.

2010-01-01

Self-joining of St. Gobain Si3N4 (NT-154) using a ductile Cu-Al-Si-Ti active braze (Cu-ABA) was demonstrated. A reaction zone approx.2.5-3.5 microns thick) developed at the interface after 30 min brazing at 1317 K. The interface was enriched in Ti and Si. The room temperature compressive shear strengths of Si3N4/Si3N4 and Inconel/Inconel joints (the latter created to access baseline data for use with the proposed Si3N4/Inconel joints) were 140+/-49MPa and 207+/-12MPa, respectively. High-temperature shear tests were performed at 1023K and 1073 K, and the strength of the Si3N4/Si3N4 and Inconel/Inconel joints were determined. The joints were metallurgically well-bonded for temperatures above 2/3 of the braze solidus. Scanning and transmission electron microscopy studies revealed a fine grain microstructure in the reaction layer, and large grains in the inner part of the joint with interfaces being crack-free. The observed formation of Ti5Si3 and AlN at the joint interface during brazing is discussed.

Fracture toughness of dentin/resin-composite adhesive interfaces.

PubMed

Tam, L E; Pilliar, R M

1993-05-01

The reliability and validity of tensile and shear bond strength determinations of dentin-bonded interfaces have been questioned. The fracture toughness value (KIC) reflects the ability of a material to resist crack initiation and unstable propagation. When applied to an adhesive interface, it should account for both interfacial bond strength and inherent defects at or near the interface, and should therefore be more appropriate for characterization of interface fracture resistance. This study introduced a fracture toughness test for the assessment of dentin/resin-composite bonded interfaces. The miniature short-rod specimen geometry was used for fracture toughness testing. Each specimen contained a tooth slice, sectioned from a bovine incisor, to form the bonded interface. The fracture toughness of an enamel-bonded interface was assessed in addition to the dentin-bonded interfaces. Tensile bond strength specimens were also prepared from the dentin surfaces of the cut bovine incisors. A minimum of ten specimens was fabricated for each group of materials tested. After the specimens were aged for 24 h in distilled water at 37 degrees C, the specimens were loaded to failure in an Instron universal testing machine. There were significant differences (p < 0.05) between the dental adhesives tested. Generally, both the fracture toughness and tensile bond strength measurements were highest for AllBond 2, intermediate for 3M MultiPurpose, and lowest for Scotchbond 2. Scanning electron microscopy of the fractured specimen halves confirmed that crack propagation occurred along the bond interface during the fracture toughness test. It was therefore concluded that the mini-short-rod fracture toughness test provided a valid method for characterization of the fracture resistance of the dentin-resin composite interface.

Small molecule correctors of F508del-CFTR discovered by structure-based virtual screening

NASA Astrophysics Data System (ADS)

Kalid, Ori; Mense, Martin; Fischman, Sharon; Shitrit, Alina; Bihler, Hermann; Ben-Zeev, Efrat; Schutz, Nili; Pedemonte, Nicoletta; Thomas, Philip J.; Bridges, Robert J.; Wetmore, Diana R.; Marantz, Yael; Senderowitz, Hanoch

2010-12-01

Folding correctors of F508del-CFTR were discovered by in silico structure-based screening utilizing homology models of CFTR. The intracellular segment of CFTR was modeled and three cavities were identified at inter-domain interfaces: (1) Interface between the two Nucleotide Binding Domains (NBDs); (2) Interface between NBD1 and Intracellular Loop (ICL) 4, in the region of the F508 deletion; (3) multi-domain interface between NBD1:2:ICL1:2:4. We hypothesized that compounds binding at these interfaces may improve the stability of the protein, potentially affecting the folding yield or surface stability. In silico structure-based screening was performed at the putative binding-sites and a total of 496 candidate compounds from all three sites were tested in functional assays. A total of 15 compounds, representing diverse chemotypes, were identified as F508del folding correctors. This corresponds to a 3% hit rate, tenfold higher than hit rates obtained in corresponding high-throughput screening campaigns. The same binding sites also yielded potentiators and, most notably, compounds with a dual corrector-potentiator activity (dual-acting). Compounds harboring both activity types may prove to be better leads for the development of CF therapeutics than either pure correctors or pure potentiators. To the best of our knowledge this is the first report of structure-based discovery of CFTR modulators.

A new apparatus for testing the delayed mechanical behaviour of interfaces: The Shearing Interfaces Creep box (SInC box)

NASA Astrophysics Data System (ADS)

Stavropoulou, Eleni; Briffaut, Matthieu; Dufour, Frédéric; Camps, Guillaume; Boulon, Marc

2017-06-01

A new experimental apparatus is presented for testing the time-dependent behaviour of interfaces, including in particular interfaces of geomaterials, under constant loading. This apparatus allows the application of two orthogonal loads normal and tangential to the mean plane of the interface, as well as the measurement of the axial and tangential relative displacements. The sample is moulded inside two half shear boxes and the system is designed in such a way that the shear force is applied along the mean plane of the interface. Some preliminary testing was carried out on a clay rock/concrete interface, under a controlled temperature environment. Preliminary results are presented, showing the evolution of the delayed displacements.

Actively controlled shaft seals for aerospace applications

NASA Technical Reports Server (NTRS)

Salant, Richard F.

1994-01-01

This study experimentally investigates an actively controlled mechanical seal for aerospace applications. The seal of interest is a gas seal, which is considerably more compact than previous actively controlled mechanical seals that were developed for industrial use. In a mechanical seal, the radial convergence of the seal interface has a primary effect on the film thickness. Active control of the film thickness is established by controlling the radial convergence of the seal interface with piezoelectric actuator. An actively controlled mechanical seal was initially designed and evaluated using a mathematical model. Based on these results, a seal was fabricated and tested under laboratory conditions. The seal was tested with both helium and air, at rotational speeds up to 3770 rad/sec, and at sealed pressures as high as 1.48 x 10(exp 6) Pa. The seal was operated with both manual control and with a closed-loop control system that used either the leakage rate or face temperature as the feedback. The output of the controller was the voltage applied to the piezoelectric actuator. The seal operated successfully for both short term tests (less than one hour) and for longer term tests (four hours) with a closed-loop control system. The leakage rates were typically 5-15 slm (standard liters per minute), and the face temperatures were generally maintained below 100 C. When leakage rate was used as the feedback signal, the setpoint leakage rate was typically maintained within 1 slm. However, larger deviations occurred during sudden changes in sealed pressure. When face temperature was used as the feedback signal, the setpoint face temperature was generally maintained within 3 C, with larger deviations occurring when the sealed pressure changed suddenly.

Green Bank Telescope active surface system

NASA Astrophysics Data System (ADS)

Lacasse, Richard J.

1998-05-01

During the design phase of the Green Bank Telescope (GBT), various means of providing an accurate surface on a large aperture paraboloid, were considered. Automated jacks supporting the primary reflector were selected as the appropriate technology since they promised greater performance and potentially lower costs than a homologous or carbon fiber design, and had certain advantages over an active secondary. The design of the active surface has presented many challenges. Since the actuators are mounted on a tipping structure, it was required that they support a significant side-load. Such devices were not readily available commercially so they had to be developed. Additional actuator requirements include low backlash, repeatable positioning, and an operational life of at least 230 years. Similarly, no control system capable of controlling the 2209 actuators was commercially available. Again a prime requirement was reliability. Maintaining was also a very important consideration. The system architecture is tree-like. An active surface 'master-computer' controls interaction with the telescope control system, and controls ancillary equipment such as power supplies and temperature monitors. Two slave computers interface with the master- computer, and each closes approximately 1100 position loops. For simplicity, the servo is an 'on/off' type, yet achieves a positioning resolution of 25 microns. Each slave computer interfaces with 4 VME I/O cards, which in turn communicate with 140 control modules. The control modules read out the positions of the actuators every 0.1 sec and control the actuators' DC motors. Initial control of the active surface will be based on an elevation dependant structural model. Later, the model will be improved by holographic observations.Surface accuracy will be improved further by using laser ranging system which will actively measure the surface figure. Several tests have been conducted to assure that the system will perform as desired when installed on the telescope. These include actuator life tests, motor life test, position transducer accuracy test, as well as positioning accuracy tests.

Surface EMG system for use in long-term vigorous activities

NASA Astrophysics Data System (ADS)

de Luca, G.; Bergman, P.; de Luca, C.

The purpose of the project was to develop an advanced surface electromyographic (EMG) system that is portable, un-tethered, and able to detect high-fidelity EMG signals from multiple channels. The innovation was specifically designed to extend NASA's capability to perform neurological status monitoring for long-term, vigorous activities. These features are a necessary requirement of ground-based and in-flight studies planned for the International Space Station and human expeditions to Mars. The project consisted of developing 1) a portable EMG digital data logger using a handheld PC for acquiring the signal and storing the data from as many as 8 channels, and 2) an EMG electrode/skin interface to improve signal fidelity and skin adhesion in the presence of sweat and mechanical disturbances encountered during vigorous activities. The system, referred to as a MyoMonitor, was configured with a communication port for downloading the data from the data logger to the PC computer workstation. Software specifications were developed and implemented for programming of acquisition protocols, power management, and transferring data to the PC for processing and graphical display. The prototype MyoMonitor was implemented using a handheld PC that features a color LCD screen, enhanced keyboard, extended Lithium Ion battery and recharger, and 128 Mbytes of F ash Memory. The system was designed to be belt-worn,l thereby allowing its use under vigorous activities. The Monitor utilizes up to 8 differential surface EMG sensors. The prototype allowed greater than 2 hours of continuous 8-channel EMG data to be collected, or 17.2 hours of continuous single channel EMG data. Standardized tests in human subjects were conducted to develop the mechanical and electrical properties of the prototype electrode/interface system. Tests conducted during treadmill running and repetitive lifting demonstrated that the prototype interface significantly reduced the detrimental effects of sweat accumulation on signal fidelity. The average number of artifacts contaminating the EMG signals during treadmill running was reduced approximat ely three-fold by the prototype electrode/interface, when compared to methods currently available. Peel adhesion of the interface to the skin was significantly improved for treadmill running. Similarly, the artifacts from controlled impacts on the electrode housing were significantly reduced for both treadmill running and for the repetitive lifting task.

Real-Time Extended Interface Automata for Software Testing Cases Generation

PubMed Central

Yang, Shunkun; Xu, Jiaqi; Man, Tianlong; Liu, Bin

2014-01-01

Testing and verification of the interface between software components are particularly important due to the large number of complex interactions, which requires the traditional modeling languages to overcome the existing shortcomings in the aspects of temporal information description and software testing input controlling. This paper presents the real-time extended interface automata (RTEIA) which adds clearer and more detailed temporal information description by the application of time words. We also establish the input interface automaton for every input in order to solve the problems of input controlling and interface covering nimbly when applied in the software testing field. Detailed definitions of the RTEIA and the testing cases generation algorithm are provided in this paper. The feasibility and efficiency of this method have been verified in the testing of one real aircraft braking system. PMID:24892080

Neuro-ergonomic Research for Online Assessment of Cognitive Workload

DTIC Science & Technology

2011-10-01

computer interface (BCI) and medical diagnoses areas. In [65], Kullback - Leibler (KL) divergence was used in the classification 39 of raw EEG signals. It...the features for each EEG channel recorded, and then compared the effectiveness of each feature using a Kruskal-Wallis test . Table 1 lists the...and the KL-distance 5-NN classifier), using different sets of activities. The feature vector and distance measures were tested in pairwise

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra aids in Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra aids in Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

OPALS: Mission System Operations Architecture for an Optical Communications Demonstration on the ISS

NASA Technical Reports Server (NTRS)

Abrahamson, Matthew J.; Sindiy, Oleg V.; Oaida, Bogdan V.; Fregoso, Santos; Bowles-Martinez, Jessica N.; Kokorowski, Michael; Wilkerson, Marcus W.; Konyha, Alexander L.

2014-01-01

In spring 2014, the Optical PAyload for Lasercomm Science (OPALS) will launch to the International Space Station (ISS) to demonstrate space-to-ground optical communications. During a 90-day baseline mission, OPALS will downlink high quality, short duration videos to the Optical Communications Telescope Laboratory (OCTL) in Wrightwood, California. To achieve mission success, interfaces to the ISS payload operations infrastructure are established. For OPALS, the interfaces facilitate activity planning, hazardous laser operations, commanding, and telemetry transmission. In addition, internal processes such as pointing prediction and data processing satisfy the technical requirements of the mission. The OPALS operations team participates in Operational Readiness Tests (ORTs) with external partners to exercise coordination processes and train for the overall mission. The tests have provided valuable insight into operational considerations on the ISS.

The STS-108 crew look over MPLM during Crew Equipment Interface Test

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- The STS-108 crew pause during their checkout of the Multi-Purpose Logistics Module Raffaello. From left are Commander Dominic L. Gorie, Mission Specialist Daniel M. Tani, Pilot Mark E. Kelly and Mission Specialist Linda A. Godwin. The four astronauts are taking part in Crew Equipment Interface Test (CEIT) activities at KSC. The CEIT provides familiarization with the launch vehicle and payload. Mission STS-108 is a Utilization Flight (UF-1), carrying the Expedition Four crew plus Multi-Purpose Logistics Module Raffaello to the International Space Station. The Expedition Four crew comprises Yuri Onufriyenko, commander, Russian Aviation and Space Agency, and astronauts Daniel W. Bursch and Carl E. Walz. Endeavour is scheduled to launch Nov. 29 on mission STS-108.

Bioavailability of Antibiotics at Soil-Water Interfaces: A Comparison of Measured Activities and Equilibrium Partitioning Estimates.

PubMed

Menz, Jakob; Müller, Julia; Olsson, Oliver; Kümmerer, Klaus

2018-06-05

There are growing concerns that antibiotic pollution impacts environmental microbiota and facilitates the propagation of antibiotic resistance. However, the prediction or analytical determination of bioavailable concentrations of antibiotics in soil is still subject to great uncertainty. Biological assays are increasingly recognized as valuable complementary tools that allow a more direct determination of the residual antibiotic activity. This study assessed the bioavailability of structurally diverse antibiotics at a soil-water interface applying activity-based analyses in conjunction with equilibrium partitioning (EqP) modeling. The activity against Gram-positive and Gram-negative bacteria of nine antibiotics from different classes was determined in the presence and absence of standard soil (LUFA St. 2.2). The addition of soil affected the activity of different antibiotics to highly varying degrees. Moreover, a highly significant correlation ( p < 0.0001) between the experimentally observed and the EqP-derived log EC 50 (half-maximal effective concentration) values was observed. The innovative experimental design of this study provided new insights on the bioavailability of antibiotics at soil-water interfaces. EqP appears to be applicable to a broad range of antibiotics for the purpose of screening-level risk assessment. However, EqP estimates cannot replace soil-specific ecotoxicity testing in higher-tier assessments, since their accuracy is still compromised by a number of factors.

A performance study of WebDav access to storages within the Belle II collaboration

NASA Astrophysics Data System (ADS)

Pardi, S.; Russo, G.

2017-10-01

WebDav and HTTP are becoming popular protocols for data access in the High Energy Physics community. The most used Grid and Cloud storage solutions provide such kind of interfaces, in this scenario tuning and performance evaluation became crucial aspects to promote the adoption of these protocols within the Belle II community. In this work, we present the results of a large-scale test activity, made with the goal to evaluate performances and reliability of the WebDav protocol, and study a possible adoption for the user analysis. More specifically, we considered a pilot infrastructure composed by a set of storage elements configured with the WebDav interface, hosted at the Belle II sites. The performance tests include a comparison with xrootd and gridftp. As reference tests we used a set of analysis jobs running under the Belle II software framework, accessing the input data with the ROOT I/O library, in order to simulate as much as possible a realistic user activity. The final analysis shows the possibility to achieve promising performances with WebDav on different storage systems, and gives an interesting feedback, for Belle II community and for other high energy physics experiments.

E-ELT M1 test facility

NASA Astrophysics Data System (ADS)

Dimmler, M.; Marrero, J.; Leveque, S.; Barriga, P.; Sedghi, B.; Mueller, M.

2012-09-01

During the advanced design phase of the European Extremely Large Telescope (E-ELT) several critical components have been prototyped. During the last year some of them have been tested in dedicated test stands. In particular, a representative section of the E-ELT primary mirror has been assembled with 2 active and 2 passive segments. This test stand is equipped with complete prototype segment subunits, i.e. including support mechanisms, glass segments, edge sensors, position actuators as well as additional metrology for monitoring. The purpose is to test various procedures such as calibration, alignment and handling and to study control strategies. In addition the achievable component and subsystem performances are evaluated, and interface issues are identified. In this paper an overview of the activities related to the E-ELT M1 Test Facility will be given. Experiences and test results are presented.

Orbiter multiplexer-demultiplexer (MDM)/Space Lab Bus Interface Unit (SL/BIU) serial data interface evaluation, volume 2

NASA Technical Reports Server (NTRS)

Tobey, G. L.

1978-01-01

Tests were performed to evaluate the operating characteristics of the interface between the Space Lab Bus Interface Unit (SL/BIU) and the Orbiter Multiplexer-Demultiplexer (MDM) serial data input-output (SIO) module. This volume contains the test equipment preparation procedures and a detailed description of the Nova/Input Output Processor Simulator (IOPS) software used during the data transfer tests to determine word error rates (WER).

Astronomical Infrastructure for Data Access (AIDA): service activities for higher education and outreach

NASA Astrophysics Data System (ADS)

Iafrate, G.; Ramella, M.; Boch, T.; Bonnarel, F.; Chèreau, F.; Fernique, P.; Osuna, P.

2009-04-01

We present preliminary simple interfaces developed to enable students, teachers, amateur astronomers and general public to access and use the wealth of astronomical data available in ground-based and space archives through the European Virtual Observatory (EuroVO). The development of these outreach interfaces are the aim of a workpackage of EuroVO-AIDA (Astronomical Infrastructure for Data Access), a project supported by EU in the framework of the FP7 Infrastructure Scientific Research Repositories initiative (project RI2121104). The aim of AIDA is to create an operating infrastructure enabling and stimulating new scientific usage of astronomy digital repositories. Euro VO AIDA is a collaboration between six European countries (PI Francoise Genova, CDS). The professional tools we adapt to the requirements of outreach activities are Aladin (CDS), Stellarium/VirGO (ESO) and VOSpec (ESA VO). Some initial requirements have been set a priori in order to produce a first version of the simplified interfaces, but the plan is to test the initial simplified versions with a sample of target users in order to take their feed-back into account for the development of the final outreach interface. The core of the test program consists of use cases we designed and complemented with proper multilingual documentation covering both the astrophysical context and the use of the software. In the special case of students in the age group 14-18 and their teachers, we take our use cases to schools. We work out the tests in classrooms supporting students working on PCs connected to the internet. At the current stage of the project, we are collecting the users feedback. Relevant links: Euro-VO AIDA Overview http://www.euro-vo.org/pub/aida/overview.html Euro-VO AIDA WP5 http://cds.u-strasbg.fr/twikiAIDA/bin/view/EuroVOAIDA/WP5WorkProgramme

Test method research on weakening interface strength of steel - concrete under cyclic loading

NASA Astrophysics Data System (ADS)

Liu, Ming-wei; Zhang, Fang-hua; Su, Guang-quan

2018-02-01

The mechanical properties of steel - concrete interface under cyclic loading are the key factors affecting the rule of horizontal load transfer, the calculation of bearing capacity and cumulative horizontal deformation. Cyclic shear test is an effective method to study the strength reduction of steel - concrete interface. A test system composed of large repeated direct shear test instrument, hydraulic servo system, data acquisition system, test control software system and so on is independently designed, and a set of test method, including the specimen preparation, the instrument preparation, the loading method and so on, is put forward. By listing a set of test results, the validity of the test method is verified. The test system and the test method based on it provide a reference for the experimental study on mechanical properties of steel - concrete interface.

Automating spectral measurements

NASA Astrophysics Data System (ADS)

Goldstein, Fred T.

2008-09-01

This paper discusses the architecture of software utilized in spectroscopic measurements. As optical coatings become more sophisticated, there is mounting need to automate data acquisition (DAQ) from spectrophotometers. Such need is exacerbated when 100% inspection is required, ancillary devices are utilized, cost reduction is crucial, or security is vital. While instrument manufacturers normally provide point-and-click DAQ software, an application programming interface (API) may be missing. In such cases automation is impossible or expensive. An API is typically provided in libraries (*.dll, *.ocx) which may be embedded in user-developed applications. Users can thereby implement DAQ automation in several Windows languages. Another possibility, developed by FTG as an alternative to instrument manufacturers' software, is the ActiveX application (*.exe). ActiveX, a component of many Windows applications, provides means for programming and interoperability. This architecture permits a point-and-click program to act as automation client and server. Excel, for example, can control and be controlled by DAQ applications. Most importantly, ActiveX permits ancillary devices such as barcode readers and XY-stages to be easily and economically integrated into scanning procedures. Since an ActiveX application has its own user-interface, it can be independently tested. The ActiveX application then runs (visibly or invisibly) under DAQ software control. Automation capabilities are accessed via a built-in spectro-BASIC language with industry-standard (VBA-compatible) syntax. Supplementing ActiveX, spectro-BASIC also includes auxiliary serial port commands for interfacing programmable logic controllers (PLC). A typical application is automatic filter handling.

Atomic Oxygen Effects on Seal Leakage

NASA Technical Reports Server (NTRS)

Christensen, John R.; Underwood, Steve D.; Kamenetzky, Rachel R.; Vaughn, Jason A.

1999-01-01

Common Berthing Mechanism (CBM provides the structural interface between separate International Space Station (ISS) elements, such as the Laboratory and Node modules. The CBM consists of an active and a passive half that join together with structural bolts. The seal at this interface is the CBM-to-CBM molded seal. The CBM-to-CBM interface is assembled on orbit, thus the seals can be exposed to the space environment for up to 65 hours. Atomic Oxygen/Vacuum Ultraviolet radiation (AO/VUV) in space is a potential hazard to the seals. Testing was conducted to determine the effect on leakage of the CBM-to-CBM seal material exposed to AO/VUV. The sealing materials were S383 silicone and V835 fluorocarbon material. Control samples, which were not exposed to the AO/VUV environment, were used to ensure that ff any changes in leakage occurred, they could be attributed to the AO/VUV exposure. After exposure to the AO/VUV environment the leakage increase was dramatic for the fluorocarbon. This testing was a major contributing factor in selecting silicone as the CBM-to-CBM seal material.

Hydrogenation of CO 2 on ZnO/Cu(100) and ZnO/Cu(111) Catalysts: Role of Copper Structure and Metal–Oxide Interface in Methanol Synthesis

DOE PAGES

Palomino, Robert M.; Ramirez, Pedro J.; Liu, Zongyuan; ...

2017-08-21

The results of kinetic tests and ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) show the important role played by a ZnO–copper interface in the generation of CO and the synthesis of methanol from CO 2 hydrogenation. The deposition of nanoparticles of ZnO on Cu(100) and Cu(111), θ oxi < 0.3 monolayer, produces highly active catalysts. The catalytic activity of these systems increases in the sequence: Cu(111) < Cu(100) < ZnO/Cu(111) < ZnO/Cu(100). The structure of the copper substrate influences the catalytic performance of a ZnO–copper interface. Furthermore, size and metal–oxide interactions affect the chemical and catalytic properties of the oxide making themore » supported nanoparticles different from bulk ZnO. The formation of a ZnO–copper interface favors the binding and conversion of CO 2 into a formate intermediate that is stable on the catalyst surface up to temperatures above 500 K. Alloys of Zn with Cu(111) and Cu(100) were not stable at the elevated temperatures (500–600 K) used for the CO 2 hydrogenation reaction. However, reaction with CO 2 oxidized the zinc, enhancing its stability over the copper substrates.« less

Hydrogenation of CO 2 on ZnO/Cu(100) and ZnO/Cu(111) Catalysts: Role of Copper Structure and Metal–Oxide Interface in Methanol Synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palomino, Robert M.; Ramirez, Pedro J.; Liu, Zongyuan

The results of kinetic tests and ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) show the important role played by a ZnO–copper interface in the generation of CO and the synthesis of methanol from CO 2 hydrogenation. The deposition of nanoparticles of ZnO on Cu(100) and Cu(111), θ oxi < 0.3 monolayer, produces highly active catalysts. The catalytic activity of these systems increases in the sequence: Cu(111) < Cu(100) < ZnO/Cu(111) < ZnO/Cu(100). The structure of the copper substrate influences the catalytic performance of a ZnO–copper interface. Furthermore, size and metal–oxide interactions affect the chemical and catalytic properties of the oxide making themore » supported nanoparticles different from bulk ZnO. The formation of a ZnO–copper interface favors the binding and conversion of CO 2 into a formate intermediate that is stable on the catalyst surface up to temperatures above 500 K. Alloys of Zn with Cu(111) and Cu(100) were not stable at the elevated temperatures (500–600 K) used for the CO 2 hydrogenation reaction. However, reaction with CO 2 oxidized the zinc, enhancing its stability over the copper substrates.« less

Strain Gage Load Calibration of the Wing Interface Fittings for the Adaptive Compliant Trailing Edge Flap Flight Test

NASA Technical Reports Server (NTRS)

Miller, Eric J.; Holguin, Andrew C.; Cruz, Josue; Lokos, William A.

2014-01-01

The safety-of-flight parameters for the Adaptive Compliant Trailing Edge (ACTE) flap experiment require that flap-to-wing interface loads be sensed and monitored in real time to ensure that the structural load limits of the wing are not exceeded. This paper discusses the strain gage load calibration testing and load equation derivation methodology for the ACTE interface fittings. Both the left and right wing flap interfaces were monitored; each contained four uniquely designed and instrumented flap interface fittings. The interface hardware design and instrumentation layout are discussed. Twenty-one applied test load cases were developed using the predicted in-flight loads. Pre-test predictions of strain gage responses were produced using finite element method models of the interface fittings. Predicted and measured test strains are presented. A load testing rig and three hydraulic jacks were used to apply combinations of shear, bending, and axial loads to the interface fittings. Hardware deflections under load were measured using photogrammetry and transducers. Due to deflections in the interface fitting hardware and test rig, finite element model techniques were used to calculate the reaction loads throughout the applied load range, taking into account the elastically-deformed geometry. The primary load equations were selected based on multiple calibration metrics. An independent set of validation cases was used to validate each derived equation. The 2-sigma residual errors for the shear loads were less than eight percent of the full-scale calibration load; the 2-sigma residual errors for the bending moment loads were less than three percent of the full-scale calibration load. The derived load equations for shear, bending, and axial loads are presented, with the calculated errors for both the calibration cases and the independent validation load cases.

P-glycoprotein ATPase activity requires lipids to activate a switch at the first transmission interface.

PubMed

Loo, Tip W; Clarke, David M

2016-04-01

P-glycoprotein (P-gp) is an ABC (ATP-Binding Cassette) drug pump. A common feature of ABC proteins is that they are organized into two wings. Each wing contains a transmembrane domain (TMD) and a nucleotide-binding domain (NBD). Drug substrates and ATP bind at the interface between the TMDs and NBDs, respectively. Drug transport involves ATP-dependent conformational changes between inward- (open, NBDs far apart) and outward-facing (closed, NBDs close together) conformations. P-gps crystallized in the presence of detergent show an open structure. Human P-gp is inactive in detergent but basal ATPase activity is restored upon addition of lipids. The lipids might cause closure of the wings to bring the NBDs close together to allow ATP hydrolysis. We show however, that cross-linking the wings together did not activate ATPase activity when lipids were absent suggesting that lipids may induce other structural changes required for ATPase activity. We then tested the effect of lipids on disulfide cross-linking of mutants at the first transmission interface between intracellular loop 4 (TMD2) and NBD1. Mutants L443C/S909C and L443C/R905C but not G471C/S909C and V472C/S909C were cross-linked with oxidant when in membranes. The mutants were then purified and cross-linked with or without lipids. Mutants G471C/S909C and V472C/S909C cross-linked only in the absence of lipids whereas mutants L443C/S909C and L443C/R905C were cross-linked only in the presence of lipids. The results suggest that lipids activate a switch at the first transmission interface and that the structure of P-gp is different in detergents and lipids. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Strain Gage Load Calibration of the Wing Interface Fittings for the Adaptive Compliant Trailing Edge Flap Flight Test

NASA Technical Reports Server (NTRS)

Miller, Eric J.; Holguin, Andrew C.; Cruz, Josue; Lokos, William A.

2014-01-01

This is the presentation to follow conference paper of the same name. The adaptive compliant trailing edge (ACTE) flap experiment safety of flight requires that the flap to wing interface loads be sensed and monitored in real time to ensure that the wing structural load limits are not exceeded. This paper discusses the strain gage load calibration testing and load equation derivation methodology for the ACTE interface fittings. Both the left and right wing flap interfaces will be monitored and each contains four uniquely designed and instrumented flap interface fittings. The interface hardware design and instrumentation layout are discussed. Twenty one applied test load cases were developed using the predicted in-flight loads for the ACTE experiment.

Reliability Growth Testing Effectiveness.

DTIC Science & Technology

1984-01-01

interface boundaries. f. Test facility and equipment descriptions and requirements. g. Procedures and timing for corrective acticns. Uh . Blocks of tme and...apporLionment, FMEA and stress analysis. Instead, reiiability "growth management provides a means of viewing all the reliability program activities in an...A VENDOR SURVEILLANCE 8 A A R GROWTH ESTING. A R PROGRAM4 C B A A NORMALIZED INCREASE 0 2.5% 25% 60 % IN ACQUISITION COST RELATIVE CHANGE IN 1:1 4:1

ISS Material Science Research Rack HWIL Interface Simulation

NASA Technical Reports Server (NTRS)

Williams, Philip J.; Ballard, Gary H.; Crumbley, Robert T. (Technical Monitor)

2002-01-01

In this paper, the first Material Science Research Rack (MSRR-1) hardware-in-the-loop (HWIL) interface simulation is described. Dynamic Concepts developed this HWIL simulation system with funding and management provided by the Flight Software group (ED14) of NASA-MSFC's Avionics Department. The HWIL system has been used both as a flight software development environment and as a software qualification tool. To fulfill these roles, the HWIL simulator accurately models the system dynamics of many MSRR-1 subsystems and emulates most of the internal interface signals. The modeled subsystems include the Experiment Modules, the Thermal Environment Control System, the Vacuum Access System, the Solid State Power Controller Module, and the Active Rack Isolation Systems. The emulated signals reside on three separate MIL-STD-1553B digital communication buses, the ISS Medium Rate Data Link, and several analog controller and sensor signals. To enhance the range of testing, it was necessary to simulate several off-nominal conditions that may occur in the interfacing subsystems.

[The Changes in the Hemodynamic Activity of the Brain during Moroe Imagery Training with the Use of Brain-Computer Interface].

PubMed

Frolov, A A; Husek, D; Silchenko, A V; Tintera, Y; Rydlo, J

2016-01-01

With the use of functional MRI (fMRI), we studied the changes in brain hemodynamic activity of healthy subjects during motor imagery training with the use brain-computer interface (BCI), which is based on the recognition of EEG patterns of imagined movements. ANOVA dispersion analysis showed there are 14 areas of the brain where statistically sgnificant changes were registered. Detailed analysis of the activity in these areas before and after training (Student's and Mann-Whitney tests) reduced the amount of areas with significantly changed activity to five; these are Brodmann areas 44 and 45, insula, middle frontal gyrus, and anterior cingulate gyrus. We suggest that these changes are caused by the formation of memory traces of those brain activity patterns which are most accurately recognized by BCI classifiers as correspondent with limb movements. We also observed a tendency of increase in the activity of motor imagery after training. The hemodynamic activity in all these 14 areas during real movements was either approximatly the same or significantly higher than during motor imagery; activity during imagined leg movements was higher that that during imagined arm movements, except for the areas of representation of arms.

Damage of actively cooled plasma facing components of magnetic confinement controlled fusion machines

NASA Astrophysics Data System (ADS)

Chevet, G.; Schlosser, J.; Martin, E.; Herb, V.; Camus, G.

2009-03-01

Plasma facing components (PFCs) of magnetic fusion machines have high manufactured residual stresses and have to withstand important stress ranges during operation. These actively cooled PFCs have a carbon fibre composite (CFC) armour and a copper alloy heat sink. Cracks mainly appear in the CFC near the composite/copper interface. In order to analyse damage mechanisms, it is important to well simulate the damage mechanisms both of the CFC and the CFC/Cu interface. This study focuses on the mechanical behaviour of the N11 material for which the scalar ONERA damage model was used. The damage parameters of this model were identified by similarity to a neighbour material, which was extensively analysed, according to the few characterization test results available for the N11. The finite elements calculations predict a high level of damage of the CFC at the interface zone explaining the encountered difficulties in the PFCs fabrication. These results suggest that the damage state of the CFC cells is correlated with a conductivity decrease to explain the temperature increase of the armour surface under fatigue heat load.

Gravity is the Key Experiment to Address the Habitability of the Ocean in Jupiter's Moon Europa

NASA Astrophysics Data System (ADS)

Sessa, A. M.; Dombard, A. J.

2013-12-01

Life requires three constituents: a liquid solvent (i.e., water), a chemical system that can form large molecules to record genetic information (e.g., carbon based) as well as chemical nutrients (e.g., nitrogen, phosphorous), and a chemical disequilibrium system that can provide metabolic energy. While it is believed that there is a saline water layer located between the rock and ice layers in Jupiter's moon Europa, which would satisfy the first requirement, it is unknown if the other conditions are currently met. The likelihood that Europa is a haven for life in our Solar System skyrockets, however, if there is currently active volcanism at the rock-water interface, much the same that volcanic processes enable the chemosynthetic life that forms the basis of deep sea-vent communities at the bottom of Earth's oceans. Exploring the volcanic activity on this interface is challenging, as direct observation via a submersible or high-resolution indirect observations via a dense global seismic network on the surface is at present technically (and fiscally!) untenable. Thus, gravity studies are the best way to explore currently the structure of this all-important interface. Though mostly a silicate body with only a relatively thin (~100 km) layer of water, Europa is different from the terrestrial planets in that this rock-water interface, and not the surface, represents the largest density contrast across the moon's near-surface layers, and thus topography on this interface could conceivably dominate the gravity. Here, we calculate the potential anomalies that arise from topography on the surface, the water-ice interface (at 20 km depth), and the rock-water interface, finding that the latter dominates the free-air gravity at the longest wavelengths (spherical harmonic degrees < 10) and the Bouguer gravity at intermediate wavelengths (degrees ~10-50), and only for the shortest wavelengths (degrees > 50) does the water-ice interface (and presumably mass-density anomalies within the ice shell) dominate the Bouguer gravity. Thus, gravity can be used to explore this interface. To test whether active volcanism can be detected, we scale gravity models for the terrestrial planets down to a body the size of Europa's silicate core and with a density contrast consistent with a rock-water interface. Here, Venus and Earth serve as proxies for volcanically active bodies, while the Moon and Mars are proxies for inactive bodies. Additionally, we create gravity from synthetic topography on the base of the ice shell. Maps of the Bouguer-gravity and geoid anomalies reveal that active volcanism is characterized by small amplitudes (a few mGal and a few meters). Large-scale topography on the base of the ice shell adds larger geoid anomalies (tens of meters) but still small gravity anomalies. The absence of volcanic activity on the rock-water interface is likely characterized by larger anomalies (tens of mGal and tens of meters), plausibly because the cooler thermal structure permits the rocky lithosphere to support larger mass-density anomalies. Thus, study of the gravity may illuminate the habitability of Europa, and gravity and topography experiments on any future mission (e.g., the Europa Clipper) should be given the highest scientific priority.

From Fulcher to PLEVALEX: Issues in Interface Design, Validity and Reliability in Internet Based Language Testing

ERIC Educational Resources Information Center

Garcia Laborda, Jesus

2007-01-01

Interface design and ergonomics, while already studied in much of educational theory, have not until recently been considered in language testing (Fulcher, 2003). In this paper, we revise the design principles of PLEVALEX, a fully operational prototype Internet based language testing platform. Our focus here is to show PLEVALEX's interfaces and…

Study on component interface evolution of a solid oxide fuel cell stack after long term operation

NASA Astrophysics Data System (ADS)

Yang, Jiajun; Huang, Wei; Wang, Xiaochun; Li, Jun; Yan, Dong; Pu, Jian; Chi, Bo; Li, Jian

2018-05-01

A 5-cell solid oxide fuel cell (SOFC) stack with external manifold structure is assembled and underwent a durability test with an output of 250 W for nearly 4400 h when current density and operating temperature are 355 mA/cm2 and 750 °C. Cells used in the stack are anode-supported cells (ASC) with yttria-stabilized zirconia (YSZ) electrolytes, Ni/YSZ hydrogen electrodes, and YSZ based composite cathode. The dimension of the cell is 150 × 150 mm (active area: 130 × 130 mm). Ceramic-glass sealant is used in the stack to keep the gas tightness between cells, interconnects and manifolds. Pure hydrogen and dry air are used as fuel and oxidant respectively. The stack has a maximum output of 340 W at 562 mA/cm2 current density at 750 °C. The stack shows a degradation of 1.5% per 1000 h during the test with 2 thermal cycles to room temperature. After the test, the stack was dissembled and examined. The relationship between microstructure changes of interfaces and degradation in the stack are discussed. The microstructure evolution of interfaces between electrode, contact material and current collector are unveiled and their relationship with the degradation is discussed.

Thermal interface material characterization for cryogenic electronic packaging solutions

NASA Astrophysics Data System (ADS)

Dillon, A.; McCusker, K.; Van Dyke, J.; Isler, B.; Christiansen, M.

2017-12-01

As applications of superconducting logic technologies continue to grow, the need for efficient and reliable cryogenic packaging becomes crucial to development and testing. A trade study of materials was done to develop a practical understanding of the properties of interface materials around 4 K. While literature exists for varying interface tests, discrepancies are found in the reported performance of different materials and in the ranges of applied force in which they are optimal. In considering applications extending from top cooling a silicon chip to clamping a heat sink, a range of forces from approximately 44 N to approximately 445 N was chosen for testing different interface materials. For each range of forces a single material was identified to optimize the thermal conductance of the joint. Of the tested interfaces, indium foil clamped at approximately 445 N showed the highest thermal conductance. Results are presented from these characterizations and useful methodologies for efficient testing are defined.

Manipulating electronic and mechanical properties at metal-ceramic interfaces with a nanomolecular layer

NASA Astrophysics Data System (ADS)

Kwan, Matthew P.

This work demonstrates that inserting nanomolecular layers (NMLs) can profoundly change and/or lead to novel electronic and mechanical properties of metal-ceramic interfaces. The first set of results demonstrate that organophosphonate NMLs up to 1.8 nm thick can alter metal work functions by +/- 0.6 eV. This work function change is a strong function of the NML terminal groups (methyl, mercaptan, carboxylic acid, or phosphonic acid), morphology (up right, lying down, or mixed orientation), and the nature of the bonding (covalent, polar, or Van der Waals) between NML and the adjacent layers. Additionally, while NML-ceramic bond type and strength can influence and counteract the effect of NML morphology, the metal-NML bond appears to be independent of the morphology of the NML underlayer. The second set of results demonstrate that inserting an organosilane NML at a metal-ceramic interface can lead to multifold fracture toughening under both static (stress corrosion) and cyclic loads (fatigue) tested in four-point bend. Nanolayer-induced interface strengthening during static loading activates metal plasticity above the metal yield strength, leading to two-fold fracture toughening. Metal plasticity-induced toughening increases as temperature is increased up to 85 °C due to decreasing yield stress. In the fatigue fracture tests I report for the first time a loading-frequency-dependent tripling in fracture toughening in the 75-300 Hz range upon inserting a mercapto-silane NML at the weakest interface of a ceramic-polymer-metal-ceramic stack. This unusual behavior arises from the NML strengthened interface enabling load transfer to- and plasticity in the polymer layer, while the fatigue toughening magnitude and frequency range are determined by polymer rheology.

Effect of Embedded Piezoelectric Sensors on Fracture Toughness and Fatigue Resistance of Composite Laminates Under Mode I Loading

NASA Technical Reports Server (NTRS)

Murri, Gretchen B.

2006-01-01

Double-cantilevered beam (DCB) specimens of a glass/epoxy composite material with embedded piezoelectric sensors were tested both statically and under fatigue loading to determine the effect of the embedded material on the Mode I fracture toughness and fatigue resistance compared to baseline data without the embedded elements. A material known as LaRC-Macrofiber Composite (LaRC-MFC (TradeMark)), or MFC, was embedded at the midplane of the specimen during the layup. Specimens were manufactured with the embedded MFC material either at the loaded end of the specimen to simulate an initial delamination; or with the MFC material located at the delaminating interface, with a Teflon film at the loaded end to simulate an initial delamination. There were three types of specimens with the embedded material at the delaminating interface: co-cured with no added adhesive; cured with a paste adhesive applied to the embedded element; or cured with a film adhesive added to the embedded material. Tests were conducted with the sensors in both the passive and active states. Results were compared to baseline data for the same material without embedded elements. Interlaminar fracture toughness values (G(sub Ic)) for the passive condition showed little change when the MFC was at the insert end. Passive results varied when the MFC was at the delaminating interface. For the co-cured case and with the paste adhesive, G(sub Ic) decreased compared to the baseline toughness, whereas, for the film adhesive case, G(sub Ic) was significantly greater than the baseline toughness, but the failure was always catastrophic. When the MFC was in the active state, G(sub Ic) was generally lower compared to the passive results. Fatigue tests showed little effect of the embedded material whether it was active or passive compared to baseline values.

Biological Tools to Study the Effects of Environmental Contaminants at the Feto–Maternal Interface

PubMed Central

Mannelli, Chiara; Ietta, Francesca; Avanzati, Anna Maria; Skarzynski, Dariusz

2015-01-01

The identification of reproductive toxicants is a major scientific challenge for human health. Prenatal life is the most vulnerable and important time span of human development. For obvious ethical reasons, in vivo models cannot be used in human pregnancy, and animal models do not perfectly reflect human physiology. This review describes the in vitro test models representative of the human feto–maternal interface and the effects of environmental chemicals with estrogen-like activity, mainly bisphenol A and para-nonylphenol, with a particular emphasis on the effects at low, nontoxic doses similar to concentrations commonly detected in the population. PMID:26740808

Improved ATLAS HammerCloud Monitoring for Local Site Administration

NASA Astrophysics Data System (ADS)

Böhler, M.; Elmsheuser, J.; Hönig, F.; Legger, F.; Mancinelli, V.; Sciacca, G.

2015-12-01

Every day hundreds of tests are run on the Worldwide LHC Computing Grid for the ATLAS, and CMS experiments in order to evaluate the performance and reliability of the different computing sites. All this activity is steered, controlled, and monitored by the HammerCloud testing infrastructure. Sites with failing functionality tests are auto-excluded from the ATLAS computing grid, therefore it is essential to provide a detailed and well organized web interface for the local site administrators such that they can easily spot and promptly solve site issues. Additional functionality has been developed to extract and visualize the most relevant information. The site administrators can now be pointed easily to major site issues which lead to site blacklisting as well as possible minor issues that are usually not conspicuous enough to warrant the blacklisting of a specific site, but can still cause undesired effects such as a non-negligible job failure rate. This paper summarizes the different developments and optimizations of the HammerCloud web interface and gives an overview of typical use cases.

Disruption of the Interaction of the Androgen Receptor with Chromatin: A Novel Therapeutic Approach in Prostate Cancer

DTIC Science & Technology

2016-10-01

DISTRIBUTION STATEMENT: Approved for Public Release; Distribution Unlimited The views, opinions and/or findings contained in this report are those of...interface between AR -FOXA1 plays important roles in AR responsiveness and activity. We have designed, synthesized, and tested a panel of peptides...peptidomimetics to disrupt the interaction between AR and FOXA1. The effects of these candidate compounds have been tested in multiple assays and various

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra (facing camera) aids in Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra (facing camera) aids in Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra talks to a technician (off-camera) during Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra talks to a technician (off-camera) during Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

User Interface Technology for Formal Specification Development

NASA Technical Reports Server (NTRS)

Lowry, Michael; Philpot, Andrew; Pressburger, Thomas; Underwood, Ian; Lum, Henry, Jr. (Technical Monitor)

1994-01-01

Formal specification development and modification are an essential component of the knowledge-based software life cycle. User interface technology is needed to empower end-users to create their own formal specifications. This paper describes the advanced user interface for AMPHION1 a knowledge-based software engineering system that targets scientific subroutine libraries. AMPHION is a generic, domain-independent architecture that is specialized to an application domain through a declarative domain theory. Formal specification development and reuse is made accessible to end-users through an intuitive graphical interface that provides semantic guidance in creating diagrams denoting formal specifications in an application domain. The diagrams also serve to document the specifications. Automatic deductive program synthesis ensures that end-user specifications are correctly implemented. The tables that drive AMPHION's user interface are automatically compiled from a domain theory; portions of the interface can be customized by the end-user. The user interface facilitates formal specification development by hiding syntactic details, such as logical notation. It also turns some of the barriers for end-user specification development associated with strongly typed formal languages into active sources of guidance, without restricting advanced users. The interface is especially suited for specification modification. AMPHION has been applied to the domain of solar system kinematics through the development of a declarative domain theory. Testing over six months with planetary scientists indicates that AMPHION's interactive specification acquisition paradigm enables users to develop, modify, and reuse specifications at least an order of magnitude more rapidly than manual program development.

Bluetooth Low Energy Peripheral Android Health App for Educational and Interoperability Testing Purposes.

PubMed

Frohner, Matthias; Urbauer, Philipp; Sauermann, Stefan

2017-01-01

Based on recent telemonitoring activities in Austria for enabling integrated health care, the communication interfaces between personal health devices (e.g. blood pressure monitor) and personal health gateway devices (e.g. smartphone, routing received information to wide area networks) play an important role. In order to ease testing of the Bluetooth Low Energy interface functionality of the personal health gateway devices, a personal health device simulator was developed. Based on specifications from the Bluetooth SIG a XML software test configuration file structure is defined that declares the specific features of the personal health devices simulated. Using this configuration file, different scenarios are defined, e.g. send a single measurement result from a blood pressure reading or sending multiple (historic) weight scale readings. The simulator is intended to be used for educational purposes in lectures, where the number of physical personal health devices can be reduced and learning can be improved. It could be shown that this simulator assists the development process of mHealth applications by reducing the time needed for development and testing.

Interface Stability Influences Torso Muscle Recruitment and Spinal Load During Pushing Tasks

PubMed Central

LEE, P. J.; GRANATA, K. P.

2006-01-01

Handle or interface design can influence torso muscle recruitment and spinal load during pushing tasks. The objective of the study was to provide insight into the role of interface stability with regard to torso muscle recruitment and biomechanical loads on the spine. Fourteen subjects generated voluntary isometric trunk flexion force against a rigid interface and similar flexion exertions against an unstable interface, which simulated handle design in a cart pushing task. Normalized electromyographic (EMG) activity in the rectus abdominus, external oblique and internal oblique muscles increased with exertion effort. When using the unstable interface, EMG activity in the internal and external oblique muscle groups was greater than when using the rigid interface. Results agreed with trends from a biomechanical model implemented to predict the muscle activation necessary to generate isometric pushing forces and maintain spinal stability when using the two different interface designs. The co-contraction contributed to increased spinal load when using the unstable interface. It was concluded that handle or interface design and stability may influence spinal load and associated risk of musculoskeletal injury during manual materials tasks that involve pushing exertions. PMID:16540437

Evaluation of sulfate reduction at experimentally induced mixing interfaces using small-scale push-pull tests in an aquifer-wetland system

USGS Publications Warehouse

Kneeshaw, T.A.; McGuire, J.T.; Smith, E.W.; Cozzarelli, I.M.

2007-01-01

This paper presents small-scale push-pull tests designed to evaluate the kinetic controls on SO42 - reduction in situ at mixing interfaces between a wetland and aquifer impacted by landfill leachate at the Norman Landfill research site, Norman, OK. Quantifying the rates of redox reactions initiated at interfaces is of great interest because interfaces have been shown to be zones of increased biogeochemical transformations and thus may play an important role in natural attenuation. To mimic the aquifer-wetland interface and evaluate reaction rates, SO42 --rich anaerobic aquifer water (??? 100 mg / L SO42 -) was introduced into SO42 --depleted wetland porewater via push-pull tests. Results showed SO42 - reduction was stimulated by the mixing of these waters and first-order rate coefficients were comparable to those measured in other push-pull studies. However, rate data were complex involving either multiple first-order rate coefficients or a more complex rate order. In addition, a lag phase was observed prior to SO42 - reduction that persisted until the mixing interface between test solution and native water was recovered, irrespective of temporal and spatial constraints. The lag phase was not eliminated by the addition of electron donor (acetate) to the injected test solution. Subsequent push-pull tests designed to elucidate the nature of the lag phase support the importance of the mixing interface in controlling terminal electron accepting processes. These data suggest redox reactions may occur rapidly at the mixing interface between injected and native waters but not in the injected bulk water mass. Under these circumstances, push-pull test data should be evaluated to ensure the apparent rate is actually a function of time and that complexities in rate data be considered. ?? 2007 Elsevier Ltd. All rights reserved.

Deformation Mechanism Map of Cu/Nb Nanoscale Metallic Multilayers as a Function of Temperature and Layer Thickness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snel, J.; Monclús, M. A.; Castillo-Rodríguez, M.

The mechanical properties and deformation mechanisms of Cu/Nb nanoscale metallic multilayers (NMMs) manufactured by accumulative roll bonding are studied at 25°C and 400°C. Cu/Nb NMMs with individual layer thicknesses between 7 nm and 63 nm were tested by in situ micropillar compression inside a scanning electron microscope. Yield strength, strain-rate sensitivities and activation volumes were obtained from the pillar compression tests. The deformed micropillars were examined under scanning and transmission electron microscopy in order to examine the deformation mechanisms active for different layer thicknesses and temperatures. The paper suggests that room temperature deformation was determined by dislocation glide at largermore » layer thicknesses and interface-related mechanisms at the thinner layer thicknesses. The high-temperature compression tests, in contrast, revealed superior thermo-mechanical stability and strength retention for the NMMs with larger layer thicknesses with deformation controlled by dislocation glide. A remarkable transition in deformation mechanism occurred as the layer thickness decreased, to a deformation response controlled by diffusion processes along the interfaces, which resulted in temperature-induced softening. Finally, a deformation mechanism map, in terms of layer thickness and temperature, is proposed from the results obtained in this investigation.« less

The further development of the active urine collection device: a novel continence management system.

PubMed

Tinnion, E; Jowitt, F; Clarke-O'Neill, S; Cottenden, A M; Fader, M; Sutherland, I

2003-01-01

Continence difficulties affect the lives of a substantial minority of the population. Women are far more likely than men to be affected by urinary incontinence but the range of management options for them is limited. There has been considerable interest in developing an external urine collection system for women but without success to date. This paper describes the development and preliminary clinical testing of an active urine collection device (AUCD), which could provide a solution for sufferers. The device uses stored vacuum, protected by a high bubble point filter, to remove urine as quickly as it is produced. This allows a small battery-operated pump to provide the required vacuum, enabling the device to be portable. Two different types of non-invasive patient/device interface were developed, and tested by volunteers: urinal and small pad. The slimline urinal was popular with users although liquid noise was a problem. The pad interface was successful on occasions but further work is necessary to produce a reliable pad. This study has successfully demonstrated that a prototype AUCD liquid handling system can remove urine at clinically relevant flowrates. While further development is required, volunteer tests have shown that the AUCD could be a useful advance in continence management.

Deformation Mechanism Map of Cu/Nb Nanoscale Metallic Multilayers as a Function of Temperature and Layer Thickness

DOE PAGES

Snel, J.; Monclús, M. A.; Castillo-Rodríguez, M.; ...

2017-08-29

The mechanical properties and deformation mechanisms of Cu/Nb nanoscale metallic multilayers (NMMs) manufactured by accumulative roll bonding are studied at 25°C and 400°C. Cu/Nb NMMs with individual layer thicknesses between 7 nm and 63 nm were tested by in situ micropillar compression inside a scanning electron microscope. Yield strength, strain-rate sensitivities and activation volumes were obtained from the pillar compression tests. The deformed micropillars were examined under scanning and transmission electron microscopy in order to examine the deformation mechanisms active for different layer thicknesses and temperatures. The paper suggests that room temperature deformation was determined by dislocation glide at largermore » layer thicknesses and interface-related mechanisms at the thinner layer thicknesses. The high-temperature compression tests, in contrast, revealed superior thermo-mechanical stability and strength retention for the NMMs with larger layer thicknesses with deformation controlled by dislocation glide. A remarkable transition in deformation mechanism occurred as the layer thickness decreased, to a deformation response controlled by diffusion processes along the interfaces, which resulted in temperature-induced softening. Finally, a deformation mechanism map, in terms of layer thickness and temperature, is proposed from the results obtained in this investigation.« less

Biomechanical effects of sitting with adjustable ischial and lumbar support on occupational low back pain: evaluation of sitting load and back muscle activity

PubMed Central

Makhsous, Mohsen; Lin, Fang; Bankard, James; Hendrix, Ronald W; Hepler, Matthew; Press, Joel

2009-01-01

Background Compared to standing posture, sitting decreases lumbar lordosis, increases low back muscle activity, disc pressure, and pressure on the ischium, which are associated with occupational LBP. A sitting device that reduces spinal load and low back muscle activities may help increase sitting comfort and reduce LBP risk. The objective of this study is to investigate the biomechanical effect of sitting with a reduced ischial support and an enhanced lumbar support (Off-Loading) on load, interface pressure and muscle activities. Methods A laboratory test in low back pain (LBP) and asymptomatic subjects was designed to test the biomechanical effect of using the Off-Loading sitting posture. The load and interface pressure on seat and the backrest, and back muscle activities associated with usual and this Off-Loading posture were recorded and compared between the two postures. Results Compared with Normal (sitting upright with full support of the seat and flat backrest) posture, sitting in Off-Loading posture significantly shifted the center of the force and the peak pressure on the seat anteriorly towards the thighs. It also significantly decreased the contact area on the seat and increased that on the backrest. It decreased the lumbar muscle activities significantly. These effects are similar in individuals with and without LBP. Conclusion Sitting with reduced ischial support and enhanced lumbar support resulted in reduced sitting load on the lumbar spine and reduced the lumbar muscular activity, which may potentially reduce sitting-related LBP. PMID:19193245

Living Together in Space: The International Space Station Internal Active Thermal Control System Issues and Solutions-Sustaining Engineering Activities at the Marshall Space Flight Center From 1998 to 2005

NASA Technical Reports Server (NTRS)

Wieland, P. O.; Roman, M. C.; Miller, L.

2007-01-01

On board the International Space Station, heat generated by the crew and equipment is removed by the internal active thermal control system to maintain a comfortable working environment and prevent equipment overheating. Test facilities simulating the internal active thermal control system (IATCS) were constructed at the Marshall Space Flight Center as part of the sustaining engineering activities to address concerns related to operational issues, equipment capability, and reliability. A full-scale functional simulator of the Destiny lab module IATCS was constructed and activated prior to launch of Destiny in 2001. This facility simulates the flow and thermal characteristics of the flight system and has a similar control interface. A subscale simulator was built, and activated in 2000, with special attention to materials and proportions of wetted surfaces to address issues related to changes in fluid chemistry, material corrosion, and microbial activity. The flight issues that have arisen and the tests performed using the simulator facilities are discussed in detail. In addition, other test facilities at the MSFC have been used to perform specific tests related to IATCS issues. Future testing is discussed as well as potential modifications to the simulators to enhance their utility.

The interdomain interface in bifunctional enzyme protein 3/4A (NS3/4A) regulates protease and helicase activities.

PubMed

Aydin, Cihan; Mukherjee, Sourav; Hanson, Alicia M; Frick, David N; Schiffer, Celia A

2013-12-01

Hepatitis C (HCV) protein 3/4A (NS3/4A) is a bifunctional enzyme comprising two separate domains with protease and helicase activities, which are essential for viral propagation. Both domains are stable and have enzymatic activity separately, and the relevance and implications of having protease and helicase together as a single protein remains to be explored. Altered in vitro activities of isolated domains compared with the full-length NS3/4A protein suggest the existence of interdomain communication. The molecular mechanism and extent of this communication was investigated by probing the domain-domain interface observed in HCV NS3/4A crystal structures. We found in molecular dynamics simulations that the two domains of NS3/4A are dynamically coupled through the interface. Interestingly, mutations designed to disrupt this interface did not hinder the catalytic activities of either domain. In contrast, substrate cleavage and DNA unwinding by these mutants were mostly enhanced compared with the wild-type protein. Disrupting the interface did not significantly alter RNA unwinding activity; however, the full-length protein was more efficient in RNA unwinding than the isolated protease domain, suggesting a more direct role in RNA processing independent of the interface. Our findings suggest that HCV NS3/4A adopts an "extended" catalytically active conformation, and interface formation acts as a switch to regulate activity. We propose a unifying model connecting HCV NS3/4A conformational states and protease and helicase function, where interface formation and the dynamic interplay between the two enzymatic domains of HCV NS3/4A potentially modulate the protease and helicase activities in vivo. © 2013 The Protein Society.

Sensitivity of indentation testing to step-off edges and interface integrity in cartilage repair.

PubMed

Bae, Won C; Law, Amanda W; Amiel, David; Sah, Robert L

2004-03-01

Step-off edges and tissue interfaces are prevalent in cartilage injury such as after intra-articular fracture and reduction, and in focal defects and surgical repair procedures such as osteochondral graft implantation. It would be useful to assess the function of injured or donor tissues near such step-off edges and the extent of integration at material interfaces. The objective of this study was to determine if indentation testing is sensitive to the presence of step-off edges and the integrity of material interfaces, in both in vitro simulated repair samples of bovine cartilage defect filled with fibrin matrix, and in vivo biological repair samples from a goat animal model. Indentation stiffness decreased at locations approaching a step-off edge, a lacerated interface, or an integrated interface in which the distal tissue was relatively soft. The indentation stiffness increased or remained constant when the site of indentation approached an integrated interface in which the distal tissue was relatively stiff or similar in stiffness to the tissue being tested. These results indicate that indentation testing is sensitive to step-off edges and interface integrity, and may be useful for assessing cartilage injury and for following the progression of tissue integration after surgical treatments.

Preparing and Testing a Magnetic Antimicrobial Silver Nanocomposite for Water Disinfection to Gain Experience at the Nanochemistry-Microbiology Interface

ERIC Educational Resources Information Center

Furlan, Ping Y.; Fisher, Adam J.; Melcer, Michael E.; Furlan, Alexander Y.; Warren, John B.

2017-01-01

We describe a 2 h introductory laboratory procedure that prepares a novel magnetic antimicrobial activated carbon nanocomposite in which nanoscale sized magnetite and silver particles are incorporated (MACAg). The MACAg nanocomposite has achieved the synergistic properties derived from its components and demonstrated its applicability as an…

Re-activation of degraded nickel cermet anodes - Nano-particle formation via reverse current pulses

NASA Astrophysics Data System (ADS)

Hauch, A.; Marchese, M.; Lanzini, A.; Graves, C.

2018-02-01

The Ni/yttria-stabilized-zirconia (YSZ) cermet is the most commonly applied fuel electrode for solid oxide cells (SOCs). Loss of Ni/YSZ electrode activity is a key life-time limiting factor of the SOC. Developing means to mitigate this loss of performance or re-activate a fuel electrode is therefore important. In this work, we report a series of five tests on state-of-the-art Ni/YSZ-YSZ-CGObarrier-LSC/CGO cells. All cells were deliberately degraded via gas stream impurities in CO2/CO or harsh steam electrolysis operation. The cells were re-activated via a variety of reverse current treatments (RCTs). Via electrochemical impedance spectroscopy, we found that the Ni/YSZ electrode performance could be recovered via RCT, but not via constant fuel cell operation. For optimized RCT, we obtained a lower Ni/YSZ electrode resistance than the initial resistance. E.g. at 700 °C we measured fuel electrode resistance of 180 mΩ cm2, 390 mΩ cm2, and 159 mΩ cm2 before degradation, after degradation and after re-activation via RCT, respectively. Post-test SEM revealed that the RCT led to formation of nano-particles in the fuel electrode. Besides the remarkable improvement, the results also showed that RCTs can weaken Ni/YSZ interfaces and the electrode/electrolyte interface. This indicates that finding an optimum RCT profile is crucial for achieving maximum benefit.

Ground Systems Development Environment (GSDE) interface requirements analysis

NASA Technical Reports Server (NTRS)

Church, Victor E.; Philips, John; Hartenstein, Ray; Bassman, Mitchell; Ruskin, Leslie; Perez-Davila, Alfredo

1991-01-01

A set of procedural and functional requirements are presented for the interface between software development environments and software integration and test systems used for space station ground systems software. The requirements focus on the need for centralized configuration management of software as it is transitioned from development to formal, target based testing. This concludes the GSDE Interface Requirements study. A summary is presented of findings concerning the interface itself, possible interface and prototyping directions for further study, and results of the investigation of the Cronus distributed applications environment.

Comparing the catalytic oxidation of ethanol at the solid-gas and solid-liquid interfaces over size-controlled Pt nanoparticles: striking differences in kinetics and mechanism.

PubMed

Sapi, Andras; Liu, Fudong; Cai, Xiaojun; Thompson, Christopher M; Wang, Hailiang; An, Kwangjin; Krier, James M; Somorjai, Gabor A

2014-11-12

Pt nanoparticles with controlled size (2, 4, and 6 nm) are synthesized and tested in ethanol oxidation by molecular oxygen at 60 °C to acetaldehyde and carbon dioxide both in the gas and liquid phases. The turnover frequency of the reaction is ∼80 times faster, and the activation energy is ∼5 times higher at the gas-solid interface compared to the liquid-solid interface. The catalytic activity is highly dependent on the size of the Pt nanoparticles; however, the selectivity is not size sensitive. Acetaldehyde is the main product in both media, while twice as much carbon dioxide was observed in the gas phase compared to the liquid phase. Added water boosts the reaction in the liquid phase; however, it acts as an inhibitor in the gas phase. The more water vapor was added, the more carbon dioxide was formed in the gas phase, while the selectivity was not affected by the concentration of the water in the liquid phase. The differences in the reaction kinetics of the solid-gas and solid-liquid interfaces can be attributed to the molecular orientation deviation of the ethanol molecules on the Pt surface in the gas and liquid phases as evidenced by sum frequency generation vibrational spectroscopy.

Intentional Voice Command Detection for Trigger-Free Speech Interface

NASA Astrophysics Data System (ADS)

Obuchi, Yasunari; Sumiyoshi, Takashi

In this paper we introduce a new framework of audio processing, which is essential to achieve a trigger-free speech interface for home appliances. If the speech interface works continually in real environments, it must extract occasional voice commands and reject everything else. It is extremely important to reduce the number of false alarms because the number of irrelevant inputs is much larger than the number of voice commands even for heavy users of appliances. The framework, called Intentional Voice Command Detection, is based on voice activity detection, but enhanced by various speech/audio processing techniques such as emotion recognition. The effectiveness of the proposed framework is evaluated using a newly-collected large-scale corpus. The advantages of combining various features were tested and confirmed, and the simple LDA-based classifier demonstrated acceptable performance. The effectiveness of various methods of user adaptation is also discussed.

Cell adhesion and proliferation on poly(tetrafluoroethylene) with plasma-metal and plasma-metal-carbon interfaces

NASA Astrophysics Data System (ADS)

Reznickova, Alena; Kvitek, Ondrej; Kolarova, Katerina; Smejkalova, Zuzana; Svorcik, Vaclav

2017-06-01

The aim of this article is to investigate the effect of the interface between plasma activated, gold and carbon coated poly(tetrafluoroethylene) (PTFE) on in vitro adhesion and spreading of mouse fibroblasts (L929). Surface properties of pristine and modified PTFE were studied by several experimental techniques. The thickness of a deposited gold film is an increasing function of the sputtering time, conversely thickness of carbon layer decreases with increasing distance between carbon source and the substrate. Because all the used surface modification techniques take place in inert Ar plasma, oxidized degradation products are formed on the PTFE surface, which affects wettability of the polymer surface. Cytocompatibility tests indicate that on samples with Au/C interface, the cells accumulate on the part of sample with evaporated carbon. Number of L929 cells proliferated on the studied samples is comparable to tissue culture polystyrene standard.

Orbital operations study. Volume 1: Mission analysis

NASA Technical Reports Server (NTRS)

Steinwachs, W. L.

1972-01-01

The final report of the orbital operations study and a summary of the 25 elements in the study inventory are presented. Fourteen interfacing activities are defined. Eleven mission models encompassing all potential interfacing element pairs and interfacing activities are included.

Radiation budget measurement/model interface

NASA Technical Reports Server (NTRS)

Vonderhaar, T. H.; Ciesielski, P.; Randel, D.; Stevens, D.

1983-01-01

This final report includes research results from the period February, 1981 through November, 1982. Two new results combine to form the final portion of this work. They are the work by Hanna (1982) and Stevens to successfully test and demonstrate a low-order spectral climate model and the work by Ciesielski et al. (1983) to combine and test the new radiation budget results from NIMBUS-7 with earlier satellite measurements. Together, the two related activities set the stage for future research on radiation budget measurement/model interfacing. Such combination of results will lead to new applications of satellite data to climate problems. The objectives of this research under the present contract are therefore satisfied. Additional research reported herein includes the compilation and documentation of the radiation budget data set a Colorado State University and the definition of climate-related experiments suggested after lengthy analysis of the satellite radiation budget experiments.

Evaluation of mechanically alloyed Cu-based powders as filler alloy for brazing tungsten to a reduced activation ferritic-martensitic steel

NASA Astrophysics Data System (ADS)

de Prado, J.; Sánchez, M.; Ureña, A.

2017-07-01

80Cu-20Ti powders were evaluated for their use as filler alloy for high temperature brazing of tungsten to a reduced activation ferritic/martensitic steel (Eurofer), and its application for the first wall of the DEMO fusion reactor. The use of alloyed powders has not been widely considered for brazing purposes and could improve the operational brazeability of the studied system due to its narrower melting range, determined by DTA analysis, which enhances the spreading capabilities of the filler. Ti contained in the filler composition acts as an activator element, reacting and forming several interfacial layers at the Eurofer-braze, which enhances the wettability properties and chemical interaction at the brazing interface. Brazing thermal cycle also activated the diffusion phenomena, which mainly affected to the Eurofer alloying elements causing in it a softening band of approximately 400 μm of thickness. However, this softening effect did not degrade the shear strength of the brazed joints (94 ± 23 MPa), because failure during testing was always located at the tungsten-braze interface.

Wireless sEMG-Based Body-Machine Interface for Assistive Technology Devices.

PubMed

Fall, Cheikh Latyr; Gagnon-Turcotte, Gabriel; Dube, Jean-Francois; Gagne, Jean Simon; Delisle, Yanick; Campeau-Lecours, Alexandre; Gosselin, Clement; Gosselin, Benoit

2017-07-01

Assistive technology (AT) tools and appliances are being more and more widely used and developed worldwide to improve the autonomy of people living with disabilities and ease the interaction with their environment. This paper describes an intuitive and wireless surface electromyography (sEMG) based body-machine interface for AT tools. Spinal cord injuries at C5-C8 levels affect patients' arms, forearms, hands, and fingers control. Thus, using classical AT control interfaces (keypads, joysticks, etc.) is often difficult or impossible. The proposed system reads the AT users' residual functional capacities through their sEMG activity, and converts them into appropriate commands using a threshold-based control algorithm. It has proven to be suitable as a control alternative for assistive devices and has been tested with the JACO arm, an articulated assistive device of which the vocation is to help people living with upper-body disabilities in their daily life activities. The wireless prototype, the architecture of which is based on a 3-channel sEMG measurement system and a 915-MHz wireless transceiver built around a low-power microcontroller, uses low-cost off-the-shelf commercial components. The embedded controller is compared with JACO's regular joystick-based interface, using combinations of forearm, pectoral, masseter, and trapeze muscles. The measured index of performance values is 0.88, 0.51, and 0.41 bits/s, respectively, for correlation coefficients with the Fitt's model of 0.75, 0.85, and 0.67. These results demonstrate that the proposed controller offers an attractive alternative to conventional interfaces, such as joystick devices, for upper-body disabled people using ATs such as JACO.

Orbital operations study. Volume 2: Interfacing activities analyses. Part 3: Data management activity group

NASA Technical Reports Server (NTRS)

Mehrbach, E.; Turkel, S. H.

1972-01-01

A summary of the findings of the data management group of the orbital operations study is presented. Element interfaces, alternate approaches, design concepts, operational procedures, functional requirements, design influences, and approach selection are described. The following interfacing activities are considered: (1) communications, (2) rendezvous, (3) stationkeeping, and (4) detached element operations.

Distributed user interfaces for clinical ubiquitous computing applications.

PubMed

Bång, Magnus; Larsson, Anders; Berglund, Erik; Eriksson, Henrik

2005-08-01

Ubiquitous computing with multiple interaction devices requires new interface models that support user-specific modifications to applications and facilitate the fast development of active workspaces. We have developed NOSTOS, a computer-augmented work environment for clinical personnel to explore new user interface paradigms for ubiquitous computing. NOSTOS uses several devices such as digital pens, an active desk, and walk-up displays that allow the system to track documents and activities in the workplace. We present the distributed user interface (DUI) model that allows standalone applications to distribute their user interface components to several devices dynamically at run-time. This mechanism permit clinicians to develop their own user interfaces and forms to clinical information systems to match their specific needs. We discuss the underlying technical concepts of DUIs and show how service discovery, component distribution, events and layout management are dealt with in the NOSTOS system. Our results suggest that DUIs--and similar network-based user interfaces--will be a prerequisite of future mobile user interfaces and essential to develop clinical multi-device environments.

Interface toughness of a zirconia-veneer system and the effect of a liner application.

PubMed

Wang, Gaoqi; Zhang, Song; Bian, Cuirong; Kong, Hui

2014-09-01

Chipping of veneering porcelain and delamination of a zirconia-veneer interface are 2 common clinical failure modes for zirconia-based restorations and may be partially due to weak interface bonding. The effect of liner on the bond strength of the interface has not been clearly identified. The purpose of the research was to evaluate the interface toughness between the zirconia core and veneering porcelain by means of a fracture mechanics test and to assess the effect of liner on the bond strength of the interface. Thirty bilayered beam-shape specimens were prepared and divided into 2 groups according to liner application. The specimens in each group were subdivided into 3 subgroups in accordance with 3 different veneer thicknesses. A fracture mechanics test was used on each specimen, and the energy release rate, G, and phase angle, ψ, were calculated according to the experimental results. A video microscope was used to monitor the crack propagation, and a scanning electron microscope was used to identify the fracture mode after testing. Two-way ANOVA and the Tukey honestly significant difference test were performed to analyze the experimental data (α=.05) . At each phase angle, the interfaces without a liner had higher mean G values than the interfaces with a liner. Both of the interfaces showed mixed failure mode with thin layers of a veneer or a liner that remained on the zirconia surfaces. Liner application before veneering reduced the interface toughness between zirconia and veneer. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Milliwatt Generator Project

NASA Astrophysics Data System (ADS)

Latimer, T. W.; Rinehart, G. H.

1992-05-01

This report covers progress on the Milliwatt Generator Project from April 1986 through March 1988. Activities included fuel processing and characterization, production of heat sources, fabrication of pressure-burst test units, compatibility studies, impact testing, and examination of surveillance units. The major task of the Los Alamos Milliwatt Generator Project is to fabricate MC2893A heat sources (4.0 W) for MC2730A radioisotope thermoelectric generators (RTG's) and MC3599 heat sources (4.5 W) for MC3500 RTG's. The MWG Project interfaces with the following contractors: Sandia National Laboratories, Albuquerque (designer); E.I. du Pont de Nemours and Co. (Inc.), Savannah River Plant (fuel); Monsanto Research Corporation, Mound Facility (metal hardware); and General Electric Company, Neutron Devices Department (RTG's). In addition to MWG fabrication activities, Los Alamos is involved in (1) fabrication of pressure-burst test units, (2) compatibility testing and evaluation, (3) examination of surveillance units, and (4) impact testing and subsequent examination of compatibility and surveillance units.

Pilot Test of a New Personal Health System Integrating Environmental and Wearable Sensors for Telemonitoring and Care of Elderly People at Home (SMARTA Project).

PubMed

Pigini, Lucia; Bovi, Gabriele; Panzarino, Claudia; Gower, Valerio; Ferratini, Maurizio; Andreoni, Giuseppe; Sassi, Roberto; Rivolta, Massimo W; Ferrarin, Maurizio

2017-01-01

The increase in life expectancy is accompanied by a growing number of elderly subjects affected by chronic comorbidities, a health issue which also implies important socioeconomic consequences. Shifting from hospital or community dwelling care towards a home personalized healthcare paradigm would promote active aging with a better quality of life, along with a reduction in healthcare-related costs. The aim of the SMARTA project was to develop and test an innovative personal health system integrating standard sensors as well as innovative wearable and environmental sensors to allow home telemonitoring of vital parameters and detection of anomalies in daily activities, thus supporting active aging through remote healthcare. A first phase of the project consisted in the definition of the health and environmental parameters to be monitored (electrocardiography and actigraphy, blood pressure and oxygen saturation, weight, ear temperature, glycemia, home interaction monitoring - water tap, refrigerator, and dishwasher), the feedbacks for the clinicians, and the reminders for the patients. It was followed by a technical feasibility analysis leading to an iterative process of prototype development, sensor integration, and testing. Once the prototype had reached an advanced stage of development, a group of 32 volunteers - including 15 healthy adult subjects, 13 elderly people with cardiac diseases, and 4 clinical operators - was recruited to test the system in a real home setting, in order to evaluate both technical reliability and user perception of the system in terms of effectiveness, usability, acceptance, and attractiveness. The testing in a real home setting showed a good perception of the SMARTA system and its functionalities both by the patients and by the clinicians, who appreciated the user interface and the clinical governance system. The moderate system reliability of 65-70% evidenced some technical issues, mainly related to sensor integration, while the patient's user interface showed excellent reliability (100%). Both elderly people and clinical operators considered the SMARTA system a promising and attractive tool for improving patients' healthcare while reducing related costs and preserving quality of life. However, the moderate reliability of the system should prompt further technical developments in terms of sensor integration and usability of the clinical operator's user interface. © 2017 S. Karger AG, Basel.

Controlling selective stimulations below a spinal cord hemisection using brain recordings with a neural interface system approach

NASA Astrophysics Data System (ADS)

Panetsos, Fivos; Sanchez-Jimenez, Abel; Torets, Carlos; Largo, Carla; Micera, Silvestro

2011-08-01

In this work we address the use of realtime cortical recordings for the generation of coherent, reliable and robust motor activity in spinal-lesioned animals through selective intraspinal microstimulation (ISMS). The spinal cord of adult rats was hemisectioned and groups of multielectrodes were implanted in both the central nervous system (CNS) and the spinal cord below the lesion level to establish a neural system interface (NSI). To test the reliability of this new NSI connection, highly repeatable neural responses recorded from the CNS were used as a pattern generator of an open-loop control strategy for selective ISMS of the spinal motoneurons. Our experimental procedure avoided the spontaneous non-controlled and non-repeatable neural activity that could have generated spurious ISMS and the consequent undesired muscle contractions. Combinations of complex CNS patterns generated precisely coordinated, reliable and robust motor actions.

Automated Rocket Propulsion Test Management

NASA Technical Reports Server (NTRS)

Walters, Ian; Nelson, Cheryl; Jones, Helene

2007-01-01

The Rocket Propulsion Test-Automated Management System provides a central location for managing activities associated with Rocket Propulsion Test Management Board, National Rocket Propulsion Test Alliance, and the Senior Steering Group business management activities. A set of authorized users, both on-site and off-site with regard to Stennis Space Center (SSC), can access the system through a Web interface. Web-based forms are used for user input with generation and electronic distribution of reports easily accessible. Major functions managed by this software include meeting agenda management, meeting minutes, action requests, action items, directives, and recommendations. Additional functions include electronic review, approval, and signatures. A repository/library of documents is available for users, and all items are tracked in the system by unique identification numbers and status (open, closed, percent complete, etc.). The system also provides queries and version control for input of all items.

bioLights: light emitting wear for visualizing lower-limb muscle activity.

PubMed

Igarashi, Naoto; Suzuki, Kenji; Kawamoto, Hiroaki; Sankai, Yoshiyuki

2010-01-01

Analysis of muscle activity by electrophysiological techniques is commonly used to analyze biomechanics. Although the simultaneous and intuitive understanding of both muscle activity and body motion is important in various fields, it is difficult to realize. This paper proposes a novel technique for visualizing physiological signals related to muscle activity by means of surface electromyography. We developed a wearable light-emitting interface that indicates lower-limb muscle activity or muscular tension on the surface of the body in real time by displaying the shape of the activated muscle. The developed interface allows users to perceive muscle activity in an intuitive manner by relating the level of the muscle activity to the brightness level of the glowing interface placed on the corresponding muscle. In order to verify the advantage of the proposed method, a cognitive experiment was conducted to evaluate the system performance. We also conducted an evaluation experiment using the developed interface in conjunction with an exoskeleton robot, in order to investigate the possible applications of the developed interface in the field of neurorehabilitation.

HELIOS Third Joint Working Group Meeting

NASA Technical Reports Server (NTRS)

Ousley, Gilbert; Kutzer, Ants

1970-01-01

During the past six months since the Second Helios Joint Working Group Meeting held 27-30 April 1970 at Goddard Space Flight Center, the TDS Sub-Group supported the Helios Project Office and the other Sub-Groups in the timely disposition of action items and the dissemination of information pertinent to the development of interface documentation. Of particular importance during this time period was the Project's decision to incorporate a single-channel telemetry system design aboard the spacecraft. The TDS Sub-Group participated actively in the process that led to this decision. Still under active study with TDS participation is the pending Project Office decision regarding the incorporation of a ranging capability within the telecommunications design. The TDS Sub-Group assisted the Mission Analysis and Operations Sub-Group in establishment of a study effort concerning the Near-Earth Sequence of Events from launch to launch plus 8 hours. This study, which will provide valuable data for the spacecraft telecommunications design, will include participation by the Experiment, Launch Vehicle, Spacecraft, as well as the TDS and MA&O Sub-Groups. Also during the past 6-month period, the TDS, in conjunction with the Spacecraft Sub-Group, initiated activity to develop the Helios Spacecraft/TDS Compatibility Test Plans and Procedures. Activity concerning the foregoing interface discussions has been and will continue to be based upon the "TDS Estimated Capabilities Document for the Helios Missions" (613-1), and the "DSN/Flight Project Interface Design Handbook" (810-5). These will continue to be considered TDS controlling documents until specific Helios Project/TDS interface documentation is generated and signed off by the respective parties. In addition to the above, the DSN continued the Helios Trainee Program with seven GfW/DFVLR trainees in residence at JPL. Two trainees will complete their year's residency concurrent with the Third Helios Joint Working Group Meeting, while four new trainees are expected to arrive following the Third Helios Joint Working Group Meeting. These and other activities are reported in detail in the paragraphs that follow.

KSC-07pd2612

NASA Image and Video Library

2007-09-28

KENNEDY SPACE CENTER, FLA. -- In the Orbiter Processing Facility, STS-122 Mission Specialist Rex Walheim reaches toward the wing of space shuttle Atlantis. The crew is at Kennedy to take part in a crew equipment interface test, or CEIT, which helps familiarize them with equipment and payloads for the mission. Among the activities standard to a CEIT are harness training, inspection of the thermal protection system and camera operation for planned extravehicular activities, or EVAs. STS-122 is targeted for launch in December. Photo credit: NASA/Kim Shiflett

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions

NASA Technical Reports Server (NTRS)

Glasgow, S. D.; Kittredge, K. B.

2003-01-01

A thermal interface material is one of the many tools often used as part of the thermal control scheme for space-based applications. Historically, at Marshall Space Flight Center, CHO-THERM 1671 has primarily been used for applications where an interface material was deemed necessary. However, numerous alternatives have come on the market in recent years. It was decided that a number of these materials should be tested against each other to see if there were better performing alternatives. The tests were done strictly to compare the thermal performance of the materials relative to each other under repeatable conditions and do not take into consideration other design issues, such as off-gassing, electrical conduction, isolation, etc. The purpose of this Technical Memorandum is to detail the materials tested, test apparatus, procedures, and results of these tests. The results show that there are a number of better performing alternatives now available.

A qualitative study adopting a user-centered approach to design and validate a brain computer interface for cognitive rehabilitation for people with brain injury.

PubMed

Martin, Suzanne; Armstrong, Elaine; Thomson, Eileen; Vargiu, Eloisa; Solà, Marc; Dauwalder, Stefan; Miralles, Felip; Daly Lynn, Jean

2017-07-14

Cognitive rehabilitation is established as a core intervention within rehabilitation programs following a traumatic brain injury (TBI). Digitally enabled assistive technologies offer opportunities for clinicians to increase remote access to rehabilitation supporting transition into home. Brain Computer Interface (BCI) systems can harness the residual abilities of individuals with limited function to gain control over computers through their brain waves. This paper presents an online cognitive rehabilitation application developed with therapists, to work remotely with people who have TBI, who will use BCI at home to engage in the therapy. A qualitative research study was completed with people who are community dwellers post brain injury (end users), and a cohort of therapists involved in cognitive rehabilitation. A user-centered approach over three phases in the development, design and feasibility testing of this cognitive rehabilitation application included two tasks (Find-a-Category and a Memory Card task). The therapist could remotely prescribe activity with different levels of difficulty. The service user had a home interface which would present the therapy activities. This novel work was achieved by an international consortium of academics, business partners and service users.

A compact electroencephalogram recording device with integrated audio stimulation system.

PubMed

Paukkunen, Antti K O; Kurttio, Anttu A; Leminen, Miika M; Sepponen, Raimo E

2010-06-01

A compact (96 x 128 x 32 mm(3), 374 g), battery-powered, eight-channel electroencephalogram recording device with an integrated audio stimulation system and a wireless interface is presented. The recording device is capable of producing high-quality data, while the operating time is also reasonable for evoked potential studies. The effective measurement resolution is about 4 nV at 200 Hz sample rate, typical noise level is below 0.7 microV(rms) at 0.16-70 Hz, and the estimated operating time is 1.5 h. An embedded audio decoder circuit reads and plays wave sound files stored on a memory card. The activities are controlled by an 8 bit main control unit which allows accurate timing of the stimuli. The interstimulus interval jitter measured is less than 1 ms. Wireless communication is made through bluetooth and the data recorded are transmitted to an external personal computer (PC) interface in real time. The PC interface is implemented with LABVIEW and in addition to data acquisition it also allows online signal processing, data storage, and control of measurement activities such as contact impedance measurement, for example. The practical application of the device is demonstrated in mismatch negativity experiment with three test subjects.

A compact electroencephalogram recording device with integrated audio stimulation system

NASA Astrophysics Data System (ADS)

Paukkunen, Antti K. O.; Kurttio, Anttu A.; Leminen, Miika M.; Sepponen, Raimo E.

2010-06-01

A compact (96×128×32 mm3, 374 g), battery-powered, eight-channel electroencephalogram recording device with an integrated audio stimulation system and a wireless interface is presented. The recording device is capable of producing high-quality data, while the operating time is also reasonable for evoked potential studies. The effective measurement resolution is about 4 nV at 200 Hz sample rate, typical noise level is below 0.7 μVrms at 0.16-70 Hz, and the estimated operating time is 1.5 h. An embedded audio decoder circuit reads and plays wave sound files stored on a memory card. The activities are controlled by an 8 bit main control unit which allows accurate timing of the stimuli. The interstimulus interval jitter measured is less than 1 ms. Wireless communication is made through bluetooth and the data recorded are transmitted to an external personal computer (PC) interface in real time. The PC interface is implemented with LABVIEW® and in addition to data acquisition it also allows online signal processing, data storage, and control of measurement activities such as contact impedance measurement, for example. The practical application of the device is demonstrated in mismatch negativity experiment with three test subjects.

Trans-Interface Optical Communication (TIOC)

DTIC Science & Technology

2008-01-01

communication interface 4. Bitmap stream creation 5. Display thread 6. DMD activeX control 7. DMD communication 8. System timing/control 9...o DMD activeX control o DMD communication o System timing/control o Graphical user interface (GUI) • All components are available for

Asynchronous P300-based brain-computer interface to control a virtual environment: initial tests on end users.

PubMed

Aloise, Fabio; Schettini, Francesca; Aricò, Pietro; Salinari, Serenella; Guger, Christoph; Rinsma, Johanna; Aiello, Marco; Mattia, Donatella; Cincotti, Febo

2011-10-01

Motor disability and/or ageing can prevent individuals from fully enjoying home facilities, thus worsening their quality of life. Advances in the field of accessible user interfaces for domotic appliances can represent a valuable way to improve the independence of these persons. An asynchronous P300-based Brain-Computer Interface (BCI) system was recently validated with the participation of healthy young volunteers for environmental control. In this study, the asynchronous P300-based BCI for the interaction with a virtual home environment was tested with the participation of potential end-users (clients of a Frisian home care organization) with limited autonomy due to ageing and/or motor disabilities. System testing revealed that the minimum number of stimulation sequences needed to achieve correct classification had a higher intra-subject variability in potential end-users with respect to what was previously observed in young controls. Here we show that the asynchronous modality performed significantly better as compared to the synchronous mode in continuously adapting its speed to the users' state. Furthermore, the asynchronous system modality confirmed its reliability in avoiding misclassifications and false positives, as previously shown in young healthy subjects. The asynchronous modality may contribute to filling the usability gap between BCI systems and traditional input devices, representing an important step towards their use in the activities of daily living.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jy-An John; Wang, Hong; Jiang, Hao

The objective of this research is to collect dynamic experimental data on spent nuclear fuel (SNF) under simulated transportation environments using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT), the hot-cell testing technology developed at Oak Ridge National Laboratory (ORNL). The collected CIRFT data will be utilized to support ongoing spent fuel modeling activities, and support SNF transportation related licensing issues. Recent testing to understand the effects of hydride reorientation on SNF vibration integrity is also being evaluated. CIRFT results have provided insight into the fuel/clad system response to transportation related loads. The major findings of CIRFT on the HBU SNFmore » are as follows: SNF system interface bonding plays an important role in SNF vibration performance, Fuel structure contributes to the SNF system stiffness, There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interaction, and SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous. Because of the non-homogeneous composite structure of the SNF system, finite element analyses (FEA) are needed to translate the global moment-curvature measurement into local stress-strain profiles. The detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained directly from a CIRFT system measurement. Therefore, detailed FEA is used to understand the global test response, and that data will also be presented.« less

The interaction of bubbles with solidification interfaces. [during coasting phase of sounding rocket flight

NASA Technical Reports Server (NTRS)

Papazian, J. M.; Wilcox, W. R.

1977-01-01

The behavior of bubbles at a dendritic solidification interface was studied during the coasting phase of a sounding rocket flight. Sequential photographs of the gradient freeze experiment showed nucleation, growth and coalescence of bubbles at the moving interface during both the low-gravity and one-gravity tests. In the one-gravity test the bubbles were observed to detach from the interface and float to the top of the melt. However, in the low-gravity tests no bubble detachment from the interface or steady state bubble motion occurred and large voids were grown into the crystal. These observations are discussed in terms of the current theory of thermal migration of bubbles and in terms of their implications on the space processing of metals.

A 3D front tracking method on a CPU/GPU system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bo, Wurigen; Grove, John

2011-01-21

We describe the method to port a sequential 3D interface tracking code to a GPU with CUDA. The interface is represented as a triangular mesh. Interface geometry properties and point propagation are performed on a GPU. Interface mesh adaptation is performed on a CPU. The convergence of the method is assessed from the test problems with given velocity fields. Performance results show overall speedups from 11 to 14 for the test problems under mesh refinement. We also briefly describe our ongoing work to couple the interface tracking method with a hydro solver.

The Deep Space Network

NASA Technical Reports Server (NTRS)

1975-01-01

The primary objectives during this portion of the extended mission were to assure survival of the spacecraft for a third Mercury encounter through conservation of attitude control gas and to conduct trajectory correction maneuvers (TCMs) as necessary to target the spacecraft for a solar occultation zone pass. Special support activities included TCMs 6 and 7 conducted on October 30, 1974 and on February 12-13, 1975, respectively. This period also saw the DSN interface organization involved in (1) the allocation of sufficient coverage to assure accurate orbit determination solutions, (2) monitoring of DSN implementation for Viking to assure maintenance of compatible interfaces and capabilities required for Mariner 10, and (3) the development of encounter coverage, sequences, and readiness test plans.

Non-linear dielectric spectroscopy of microbiological suspensions

PubMed Central

Treo, Ernesto F; Felice, Carmelo J

2009-01-01

Background Non-linear dielectric spectroscopy (NLDS) of microorganism was characterized by the generation of harmonics in the polarization current when a microorganism suspension was exposed to a sinusoidal electric field. The biological nonlinear response initially described was not well verified by other authors and the results were susceptible to ambiguous interpretation. In this paper NLDS was performed to yeast suspension in tripolar and tetrapolar configuration with a recently developed analyzer. Methods Tripolar analysis was carried out by applying sinusoidal voltages up to 1 V at the electrode interface. Tetrapolar analysis was carried on with sinusoidal field strengths from 0.1 V cm-1 to 70 V cm-1. Both analyses were performed within a frequency range from 1 Hz through 100 Hz. The harmonic amplitudes were Fourier-analyzed and expressed in dB. The third harmonic, as reported previously, was investigated. Statistical analysis (ANOVA) was used to test the effect of inhibitor an activator of the plasma membrane enzyme in the measured response. Results No significant non-linearities were observed in tetrapolar analysis, and no observable changes occurred when inhibitor and activator were added to the suspension. Statistical analysis confirmed these results. When a pure sinus voltage was applied to an electrode-yeast suspension interface, variations higher than 25 dB for the 3rd harmonic were observed. Variation higher than 20 dB in the 3rd harmonics has also been found when adding an inhibitor or activator of the membrane-bounded enzymes. These variations did not occur when the suspension was boiled. Discussion The lack of result in tetrapolar cells suggest that there is no, if any, harmonic generation in microbiological bulk suspension. The non-linear response observed was originated in the electrode-electrolyte interface. The frequency and voltage windows observed in previous tetrapolar analysis were repeated in the tripolar measurements, but maximum were not observed at the same values. Conclusion Contrary to previous assertions, no repeatable dielectric non-linearity was exhibited in the bulk suspensions tested under the field and frequency condition reported with this recently designed analyzer. Indeed, interface related harmonics were observed and monitored during biochemical stimuli. The changes were coherent with the expected biological response. PMID:19772595

An analysis of fiber-matrix interface failure stresses for a range of ply stress states

NASA Technical Reports Server (NTRS)

Crews, J. H.; Naik, R. A.; Lubowinski, S. J.

1993-01-01

A graphite/bismaleimide laminate was prepared without the usual fiber treatment and was tested over a wide range of stress states to measure its ply cracking strength. These tests were conducted using off-axis flexure specimens and produced fiber-matrix interface failure data over a correspondingly wide range of interface stress states. The absence of fiber treatment, weakened the fiber-matrix interfaces and allowed these tests to be conducted at load levels that did not yield the matrix. An elastic micromechanics computer code was used to calculate the fiber-matrix interface stresses at failure. Two different fiber-array models (square and diamond) were used in these calculations to analyze the effects of fiber arrangement as well as stress state on the critical interface stresses at failure. This study showed that both fiber-array models were needed to analyze interface stresses over the range of stress states. A linear equation provided a close fit to these critical stress combinations and, thereby, provided a fiber-matrix interface failure criterion. These results suggest that prediction procedures for laminate ply cracking can be based on micromechanics stress analyses and appropriate fiber-matrix interface failure criteria. However, typical structural laminates may require elastoplastic stress analysis procedures that account for matrix yielding, especially for shear-dominated ply stress states.

Determination of fiber-matrix interface failure parameters from off-axis tests

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.; Crews, John H., Jr.

1993-01-01

Critical fiber-matrix (FM) interface strength parameters were determined using a micromechanics-based approach together with failure data from off-axis tension (OAT) tests. The ply stresses at failure for a range of off-axis angles were used as input to a micromechanics analysis that was performed using the personal computer-based MICSTRAN code. FM interface stresses at the failure loads were calculated for both the square and the diamond array models. A simple procedure was developed to determine which array had the more severe FM interface stresses and the location of these critical stresses on the interface. For the cases analyzed, critical FM interface stresses were found to occur with the square array model and were located at a point where adjacent fibers were closest together. The critical FM interface stresses were used together with the Tsai-Wu failure theory to determine a failure criterion for the FM interface. This criterion was then used to predict the onset of ply cracking in angle-ply laminates for a range of laminate angles. Predictions for the onset of ply cracking in angle-ply laminates agreed with the test data trends.

ASTM and VAMAS activities in titanium matrix composites test methods development

NASA Technical Reports Server (NTRS)

Johnson, W. S.; Harmon, D. M.; Bartolotta, P. A.; Russ, S. M.

1994-01-01

Titanium matrix composites (TMC's) are being considered for a number of aerospace applications ranging from high performance engine components to airframe structures in areas that require high stiffness to weight ratios at temperatures up to 400 C. TMC's exhibit unique mechanical behavior due to fiber-matrix interface failures, matrix cracks bridged by fibers, thermo-viscoplastic behavior of the matrix at elevated temperatures, and the development of significant thermal residual stresses in the composite due to fabrication. Standard testing methodology must be developed to reflect the uniqueness of this type of material systems. The purpose of this paper is to review the current activities in ASTM and Versailles Project on Advanced Materials and Standards (VAMAS) that are directed toward the development of standard test methodology for titanium matrix composites.

KSC-00pp1766

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- Some of the STS-98 crew look over the Canadian robotic arm in the payload bay of orbiter Atlantis, which is undergoing testing in the Orbiter Processing Facility bay 3. At right, pointing, is Mission Specialist Tom Jones. Second from right is Mission Specialist Robert Curbeam. They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1766

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- Some of the STS-98 crew look over the Canadian robotic arm in the payload bay of orbiter Atlantis, which is undergoing testing in the Orbiter Processing Facility bay 3. At right, pointing, is Mission Specialist Tom Jones. Second from right is Mission Specialist Robert Curbeam. They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra (second from right) talks with workers in the Space Station Processing Facility about the Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. . The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra (second from right) talks with workers in the Space Station Processing Facility about the Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. . The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

Experimental investigation on IXV TPS interface effects in Plasmatron

NASA Astrophysics Data System (ADS)

Ceglia, Giuseppe; Trifoni, Eduardo; Gouriet, Jean-Baptiste; Chazot, Olivier; Mareschi, Vincenzo; Rufolo, Giuseppe; Tumino, Giorgio

2016-06-01

An experimental investigation related to the thermal protection system (TPS) interfaces of the intermediate experimental vehicle has been carried out in the Plasmatron facility at the von Karman Institute for fluid dynamics. The objective of this test campaign is to qualify the thermal behaviours of two different TPS interfaces under flight representative conditions in terms of heat flux and integral heat load ( 180 kW/m2 for 700 s). Three test samples are tested in off-stagnation configuration installed on an available flat plate holder under the same test conditions. The first junction is composed of an upstream ceramic matrix composite (CMC) plate and an ablative P50 cork composite block separated by a gap of 2 mm. The second one is made of an upstream P50 block and a downstream ablative SV2A silicon elastomer block with silicon-based filler in between. A sample composed of P50 material is tested in order to obtain reference results without TPS interface effect. The overheating at the CMC-P50 interface due to the jump of the catalytic properties of the materials, and the recession/swelling behaviour of the P50-SV2A interface are under investigation. All the test samples withstand relatively well the imposed heat flux for the test duration. As expected, both the ablative materials undergo a thermal degradation. The P50 exhibits the formation of a porous char layer and its recession; on the other hand, the SV2A swells and forms a fragile char layer.

78 FR 36642 - Proposed Information Collection (VA Loan Electronic Reporting Interface (VALERI) System) Activity...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-18

... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-0021] Proposed Information Collection (VA Loan Electronic Reporting Interface (VALERI) System) Activity: Comment Request AGENCY: Veterans... techniques or the use of other forms of information technology. Title: VA Loan Electronic Reporting Interface...

The Impact of Settable Test Item Exposure Control Interface Format on Postsecondary Business Student Test Performance

ERIC Educational Resources Information Center

Truell, Allen D.; Zhao, Jensen J.; Alexander, Melody W.

2005-01-01

The purposes of this study were to determine if there is a significant difference in postsecondary business student scores and test completion time based on settable test item exposure control interface format, and to determine if there is a significant difference in student scores and test completion time based on settable test item exposure…

The Mechanical Performance of Subscale Candidate Elastomer Docking Seals

NASA Technical Reports Server (NTRS)

Bastrzyk, Marta B.; Daniels, Christopher C.

2010-01-01

The National Aeronautics and Space Administration is developing a Low Impact Docking System (LIDS) for future exploration missions. The mechanism is a new state-of-the-art device for in-space assembly of structures and rendezvous of vehicles. At the interface between two pressurized modules, each with a version of the LIDS attached, a composite elastomer-metal seal assembly prevents the breathable air from escaping into the vacuum of space. Attached to the active LIDS, this seal mates against the passive LIDS during docking operation. The main interface seal assembly must exhibit low leak and outgas values, must be able to withstand various harsh space environments, must remain operational over a range of temperatures from -50 C to 75 C, and perform after numerous docking cycles. This paper presents results from a comprehensive study of the mechanical performance of four candidate subscale seal assembly designs at -50, 23, 50, and 75 C test temperatures. In particular, the force required to fully compress the seal during docking, and that which is required for separation during the undocking operation were measured. The height of subscale main interface seal bulbs, as well as the test temperature, were shown to have a significant effect on the forces the main interface seal of the LIDS may experience during docking and undocking operations. The average force values required to fully compress each of the seal assemblies were shown to increase with test temperature by approximately 50% from -50 to 75 C. Also, the required compression forces were shown to increase as the height of the seal bulb was increased. The seal design with the tallest elastomer seal bulb, which was 31% taller than that with the shortest bulb, required force values approximately 45% higher than those for the shortest bulb, independent of the test temperature. The force required to separate the seal was shown to increase with decreasing temperature after 15 hours of simulated docking. No adhesion force was observed at 75 C, while magnitudes of up to 235 lbf were recorded at the refrigerated temperature. In addition, the adhesion force was observed to increase with bulb height. When compared with the LIDS program requirements, the measured compression force values were found to be below the maximum allowable load allotted to the main interface seal. However, the measured adhesion force values at the refrigerated test temperature were found to exceed the program limits.

Decoding bipedal locomotion from the rat sensorimotor cortex.

PubMed

Rigosa, J; Panarese, A; Dominici, N; Friedli, L; van den Brand, R; Carpaneto, J; DiGiovanna, J; Courtine, G; Micera, S

2015-10-01

Decoding forelimb movements from the firing activity of cortical neurons has been interfaced with robotic and prosthetic systems to replace lost upper limb functions in humans. Despite the potential of this approach to improve locomotion and facilitate gait rehabilitation, decoding lower limb movement from the motor cortex has received comparatively little attention. Here, we performed experiments to identify the type and amount of information that can be decoded from neuronal ensemble activity in the hindlimb area of the rat motor cortex during bipedal locomotor tasks. Rats were trained to stand, step on a treadmill, walk overground and climb staircases in a bipedal posture. To impose this gait, the rats were secured in a robotic interface that provided support against the direction of gravity and in the mediolateral direction, but behaved transparently in the forward direction. After completion of training, rats were chronically implanted with a micro-wire array spanning the left hindlimb motor cortex to record single and multi-unit activity, and bipolar electrodes into 10 muscles of the right hindlimb to monitor electromyographic signals. Whole-body kinematics, muscle activity, and neural signals were simultaneously recorded during execution of the trained tasks over multiple days of testing. Hindlimb kinematics, muscle activity, gait phases, and locomotor tasks were decoded using offline classification algorithms. We found that the stance and swing phases of gait and the locomotor tasks were detected with accuracies as robust as 90% in all rats. Decoded hindlimb kinematics and muscle activity exhibited a larger variability across rats and tasks. Our study shows that the rodent motor cortex contains useful information for lower limb neuroprosthetic development. However, brain-machine interfaces estimating gait phases or locomotor behaviors, instead of continuous variables such as limb joint positions or speeds, are likely to provide more robust control strategies for the design of such neuroprostheses.

KSC00pp1772

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- In the Orbiter Processing Facility, STS-98 Mission Specialists Robert Curbeam (center left) and Tom Jones (center right) practice with tools that will be used on extravehicular activities on their mission. The STS-98 crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC-00pp1772

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- In the Orbiter Processing Facility, STS-98 Mission Specialists Robert Curbeam (center left) and Tom Jones (center right) practice with tools that will be used on extravehicular activities on their mission. The STS-98 crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

Human perceptual deficits as factors in computer interface test and evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowser, S.E.

1992-06-01

Issues related to testing and evaluating human computer interfaces are usually based on the machine rather than on the human portion of the computer interface. Perceptual characteristics of the expected user are rarely investigated, and interface designers ignore known population perceptual limitations. For these reasons, environmental impacts on the equipment will more likely be defined than will user perceptual characteristics. The investigation of user population characteristics is most often directed toward intellectual abilities and anthropometry. This problem is compounded by the fact that some deficits capabilities tend to be found in higher-than-overall population distribution in some user groups. The testmore » and evaluation community can address the issue from two primary aspects. First, assessing user characteristics should be extended to include tests of perceptual capability. Secondly, interface designs should use multimode information coding.« less

Socket Interface Pressure and Amputee Reported Outcomes for Comfortable and Uncomfortable Conditions of Patellar Tendon Bearing Socket: A Pilot Study.

PubMed

Safari, Mohammad Reza; Tafti, Nahid; Aminian, Gholamreza

2015-01-01

The objectives of the current study were to compare intra-socket pressure differences between comfortable and uncomfortable socket conditions, and the usefulness of subject perception of satisfaction, activity limitations, and socket comfort in distinguishing between these two socket conditions. Five unilateral trans-tibial amputees took part in the study. They answered the Socket Comfort Score (SCS) and Trinity Amputation and Prosthetic Experience Scale (TAPES) questionnaires before the interface pressure (in standing and walking) was measured for the uncomfortable socket condition at five regions of the residual limb. Participants were then provided with a comfortable socket and wore it for two weeks. Participants who were satisfied with the socket fit after two weeks repeated the SCS and TAPES questionnaires and interface pressure measurements. The differences between the test results of the two conditions were not statistically significant, except for the interface pressure at the popliteal region during the early stance phase, TAPES socket fit subscale, and the SCS. Due to large variability of the data and the lack of statistical significance, no firm conclusion can be made on the possible relationship between the interface pressure values and the patient-reported outcomes of the two socket conditions. A larger sample size and longer acclimation period are required to locate significant differences.

Design and Evaluation of a Cable-Driven fMRI-Compatible Haptic Interface to Investigate Precision Grip Control

PubMed Central

Vigaru, Bogdan; Sulzer, James; Gassert, Roger

2016-01-01

Our hands and fingers are involved in almost all activities of daily living and, as such, have a disproportionately large neural representation. Functional magnetic resonance imaging investigations into the neural control of the hand have revealed great advances, but the harsh MRI environment has proven to be a challenge to devices capable of delivering a large variety of stimuli necessary for well-controlled studies. This paper presents a fMRI-compatible haptic interface to investigate the neural mechanisms underlying precision grasp control. The interface, located at the scanner bore, is controlled remotely through a shielded electromagnetic actuation system positioned at the end of the scanner bed and then through a high stiffness, low inertia cable transmission. We present the system design, taking into account requirements defined by the biomechanics and dynamics of the human hand, as well as the fMRI environment. Performance evaluation revealed a structural stiffness of 3.3 N/mm, renderable forces up to 94 N, and a position control bandwidth of at least 19 Hz. MRI-compatibility tests showed no degradation in the operation of the haptic interface or the image quality. A preliminary fMRI experiment during a pilot study validated the usability of the haptic interface, illustrating the possibilities offered by this device. PMID:26441454

Prosthesis Control with an Implantable Multichannel Wireless Electromyography System for High-Level Amputees: A Large-Animal Study.

PubMed

Bergmeister, Konstantin D; Hader, Marie; Lewis, Soeren; Russold, Michael-Friedrich; Schiestl, Martina; Manzano-Szalai, Krisztina; Roche, Aidan D; Salminger, Stefan; Dietl, Hans; Aszmann, Oskar C

2016-01-01

Myoelectric prostheses lack a strong human-machine interface, leading to high abandonment rates in upper limb amputees. Implantable wireless electromyography systems improve control by recording signals directly from muscle, compared with surface electromyography. These devices do not exist for high amputation levels. In this article, the authors present an implantable wireless electromyography system for these scenarios tested in Merino sheep for 4 months. In a pilot trial, the electrodes were implanted in the hind limbs of 24 Sprague-Dawley rats. After 8 or 12 weeks, impedance and histocompatibility were assessed. In the main trial, the system was tested in four Merino sheep for 4 months. Impedance of the electrodes was analyzed in two animals. Electromyographic data were analyzed in two freely moving animals repeatedly during forward and backward gait. Device implantation was successful in all 28 animals. Histologic evaluation showed a tight encapsulation after 8 weeks of 78.2 ± 26.5 µm subcutaneously and 92.9 ± 31.3 µm on the muscular side. Electromyographic recordings show a distinct activation pattern of the triceps, brachialis, and latissimus dorsi muscles, with a low signal-to-noise ratio, representing specific patterns of agonist and antagonist activation. Average electrode impedance decreased over the whole frequency range, indicating an improved electrode-tissue interface during the implantation. All measurements taken over the 4 months of observation used identical settings and showed similar recordings despite changing environmental factors. This study shows the implantation of this electromyography device as a promising alternative to surface electromyography, providing a potentially powerful wireless interface for high-level amputees.

Photo-activated luminescence sensor and method of detecting trichloroethylene and related volatile organochloride compounds

DOEpatents

Dinh, Tuan V.

1996-01-01

A sensor for detecting trichloroethylene and related volatile organochloride compounds uses a photo-activator that produces a photo-product complex with the contaminant. Characteristics of the light emitted from the complex will indicate the presence of the contaminant. A probe containing the photo-activator has an excitation light interface and a contaminant interface. One particular embodiment uses a porous membrane as the contaminant interface, so that the contaminant can migrate therethrough to the photo-activator and thereby form the complex.

Stability and activity modulation of chymotrypsins in AOT reversed micelles by protein-interface interaction: interaction of alpha-chymotrypsin with a negative interface leads to a cooperative breakage of a salt bridge that keeps the catalytic active conformation (Ile16-Asp194).

PubMed

Almeida, F C; Valente, A P; Chaimovich, H

1998-08-05

The stability of alpha-chymotrypsin and delta-chymotrypsin was studied in reversed micelles of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in isooctane. alpha-Chymotrypsin is inactivated at the interface and at the water pool, while delta-chymotrypsin is inactivated only at the water pool. The mechanism of inactivation at the interface is related to the interaction of N-terminal group alanine 149 (absent in delta-chymotrypsin) with the negative interface. The dependence of enzyme activity on water content of these two enzymes in reversed micelles of AOT is also related with the interface interaction, since delta-chymotrypsin does not have a bell-shaped curve as observed for alpha-chymotrypsin. Copyright 1998 John Wiley & Sons, Inc.

MPLM On-Orbit Interface Dynamic Flexibility Modal Test

NASA Technical Reports Server (NTRS)

Bookout, Paul S.; Rodriguez, Pedro I.; Tinson, Ian; Fleming, Paolo

2001-01-01

Now that the International Space Station (ISS) is being constructed, payload developers have to not only verify the Shuttle-to-payload interface, but also the interfaces their payload will have with the ISS. The Multi Purpose Logistic Module (MPLM) being designed and built by Alenia Spazio in Torino, Italy is one such payload. The MPLM is the primary carrier for the ISS Payload Racks, Re-supply Stowage Racks, and the Resupply Stowage Platforms to re-supply the ISS with food, water, experiments, maintenance equipment and etc. During the development of the MPLM there was no requirement for verification of the on-orbit interfaces with the ISS. When this oversight was discovered, all the dynamic test stands had already been disassembled. A method was needed that would not require an extensive testing stand and could be completed in a short amount of time. The residual flexibility testing technique was chosen. The residual flexibility modal testing method consists of measuring the free-free natural frequencies and mode shapes along with the interface frequency response functions (FRF's). Analytically, the residual flexibility method has been investigated in detail by, MacNeal, Martinez, Carne, and Miller, and Rubin, but has not been implemented extensively for model correlation due to difficulties in data acquisition. In recent years improvement of data acquisition equipment has made possible the implementation of the residual flexibility method as in Admire, Tinker, and Ivey, and Klosterman and Lemon. The residual flexibility modal testing technique is applicable to a structure with distinct points (DOF) of contact with its environment, such as the MPLM-to-Station interface through the Common Berthing Mechanism (CBM). The CBM is bolted to a flange on the forward cone of the MPLM. During the fixed base test (to verify Shuttle interfaces) some data was gathered on the forward cone panels. Even though there was some data on the forward cones, an additional modal test was performed to better characterize its behavior. The CBM mounting flange is the only remaining structure of the MPLM that no test data was available. This paper discusses the implementation of the residual flexibility modal testing technique on the CBM flange and the modal test of the forward cone panels.

A Cross-Cultural Test of the Work-Family Interface in 48 Countries

ERIC Educational Resources Information Center

Jeffrey Hill, E.; Yang, Chongming; Hawkins, Alan J.; Ferris, Maria

2004-01-01

This study tests a cross-cultural model of the work-family interface. Using multigroup structural equation modeling with IBM survey responses from 48 countries (N= 25,380), results show that the same work-family interface model that fits the data globally also fits the data in a four-group model composed of culturally related groups of countries,…

International Instrumentation Symposium, 32nd, Seattle, WA, May 5-8, 1986, Proceedings

NASA Astrophysics Data System (ADS)

The conference presents papers on blast, shock, and vibration instrumentation; wind tunnel instrumentation and controls; electrooptic and fiber optic instrumentation; special test facilities; reentry vehicle testing; and nondestructive test and acoustic test instrumentation. Other topic include real time systems, flight test and avionics instrumentation, data aquisition and analysis systems, thermal measurements, and advances in measurement technology. Particular attention is given to an automated fringe counting laser interferometer for low frequency vibration measurements, dynamic pressure measurements in pneumatic lines, optically interfaced sensor system for aerospace applications, the picobalance for single microparticle measurements, ellipsometric film thickness, nanometer wear measurement by ultrathin surface layer activation, a rugged electronic scanner designed for turbine test, failure mechanism characterization of platinum alloy, and the thick film strain gage.

Concentration on performance with P300-based BCI systems: a matter of interface features.

PubMed

da Silva-Sauer, Leandro; Valero-Aguayo, Luis; de la Torre-Luque, Alejandro; Ron-Angevin, Ricardo; Varona-Moya, Sergio

2016-01-01

People who suffer from severe motor disabilities have difficulties to communicate with others or to interact with their environment using natural, i.e., muscular channels. These limitations can be overcome to some extent by using brain-computer interfaces (BCIs), because such systems allow users to communicate on the basis of their brain activity only. Among the several types of BCIs for spelling purposes, those that rely on the P300 event related potential-P300-based spellers-are chosen preferentially due to their high reliability. However, they demand from the user to sustain his/her attention to the desired character over a relatively long period of time. Therefore, the user's capacity to concentrate can affect his/her performance with a P300-based speller. The aim of this study was to test this hypothesis using three different interfaces: one based on the classic P300 speller paradigm, another also based on that speller but including a word predictor, and a third one that was based on the T9 interface developed for mobile phones. User performance was assessed by measuring the time to complete a spelling task and the accuracy of character selection. The d2 test was applied to assess attention and concentration. Sample (N = 14) was divided into two groups basing on of concentration scores. As a result, performance was better with the predictor-enriched interfaces: less time was needed to solve the task and participants made fewer errors (p < .05). There were also significant effects of concentration (p < .05) on performance with the standard P300 speller. In conclusion, the performance of those users with lower concentration level can be improved by providing BCIs with more interactive interfaces. These findings provide substantial evidence in order to highlight the impact of psychological features on BCI performance and should be taken into account for future assistive technology systems. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

A novel active heads-up display for driver assistance.

PubMed

Doshi, Anup; Cheng, Shinko Yuanhsien; Trivedi, Mohan Manubhai

2009-02-01

In this paper, we introduce a novel laser-based wide-area heads-up windshield display which is capable of actively interfacing with a human as part of a driver assistance system. The dynamic active display (DAD) is a unique prototype interface that presents safety-critical visual icons to the driver in a manner that minimizes the deviation of his or her gaze direction without adding to unnecessary visual clutter. As part of an automotive safety system, the DAD presents alerts in the field of view of the driver only if necessary, which is based upon the state and pose of the driver, vehicle, and environment. This paper examines the effectiveness of DAD through a comprehensive comparative experimental evaluation of a speed compliance driver assistance system, which is implemented on a vehicular test bed. Three different types of display protocols for assisting a driver to comply with speed limits are tested on actual roadways, and these are compared with a conventional dashboard display. Given the inclination, drivers who are given an overspeed warning alert reduced the time required to slow down to the speed limit by 38% (p < 0.01) as compared with the drivers not given the alert. Additionally, certain alerts decreased distraction levels by reducing the time spent looking away from the road by 63% (p < 0.01). Ultimately, these alerts demonstrate the utility and promise of the DAD system.

Imaging Sensor Flight and Test Equipment Software

NASA Technical Reports Server (NTRS)

Freestone, Kathleen; Simeone, Louis; Robertson, Byran; Frankford, Maytha; Trice, David; Wallace, Kevin; Wilkerson, DeLisa

2007-01-01

The Lightning Imaging Sensor (LIS) is one of the components onboard the Tropical Rainfall Measuring Mission (TRMM) satellite, and was designed to detect and locate lightning over the tropics. The LIS flight code was developed to run on a single onboard digital signal processor, and has operated the LIS instrument since 1997 when the TRMM satellite was launched. The software provides controller functions to the LIS Real-Time Event Processor (RTEP) and onboard heaters, collects the lightning event data from the RTEP, compresses and formats the data for downlink to the satellite, collects housekeeping data and formats the data for downlink to the satellite, provides command processing and interface to the spacecraft communications and data bus, and provides watchdog functions for error detection. The Special Test Equipment (STE) software was designed to operate specific test equipment used to support the LIS hardware through development, calibration, qualification, and integration with the TRMM spacecraft. The STE software provides the capability to control instrument activation, commanding (including both data formatting and user interfacing), data collection, decompression, and display and image simulation. The LIS STE code was developed for the DOS operating system in the C programming language. Because of the many unique data formats implemented by the flight instrument, the STE software was required to comprehend the same formats, and translate them for the test operator. The hardware interfaces to the LIS instrument using both commercial and custom computer boards, requiring that the STE code integrate this variety into a working system. In addition, the requirement to provide RTEP test capability dictated the need to provide simulations of background image data with short-duration lightning transients superimposed. This led to the development of unique code used to control the location, intensity, and variation above background for simulated lightning strikes at user-selected locations.

Chronic monitoring of lower urinary tract activity via a sacral dorsal root ganglia interface

NASA Astrophysics Data System (ADS)

Khurram, Abeer; Ross, Shani E.; Sperry, Zachariah J.; Ouyang, Aileen; Stephan, Christopher; Jiman, Ahmad A.; Bruns, Tim M.

2017-06-01

Objective. Our goal is to develop an interface that integrates chronic monitoring of lower urinary tract (LUT) activity with stimulation of peripheral pathways. Approach. Penetrating microelectrodes were implanted in sacral dorsal root ganglia (DRG) of adult male felines. Peripheral electrodes were placed on or in the pudendal nerve, bladder neck and near the external urethral sphincter. Supra-pubic bladder catheters were implanted for saline infusion and pressure monitoring. Electrode and catheter leads were enclosed in an external housing on the back. Neural signals from microelectrodes and bladder pressure of sedated or awake-behaving felines were recorded under various test conditions in weekly sessions. Electrodes were also stimulated to drive activity. Main results. LUT single- and multi-unit activity was recorded for 4-11 weeks in four felines. As many as 18 unique bladder pressure single-units were identified in each experiment. Some channels consistently recorded bladder afferent activity for up to 41 d, and we tracked individual single-units for up to 23 d continuously. Distension-evoked and stimulation-driven (DRG and pudendal) bladder emptying was observed, during which LUT sensory activity was recorded. Significance. This chronic implant animal model allows for behavioral studies of LUT neurophysiology and will allow for continued development of a closed-loop neuroprosthesis for bladder control.

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions

NASA Technical Reports Server (NTRS)

Glasgow, Shaun; Kittredge, Ken

2003-01-01

A thermal interface material is one of the many tools that are often used as part of the thermal control scheme for space-based applications. These materials are placed between, for example, an avionics box and a cold plate, in order to improve the conduction heat transfer so that proper temperatures can be maintained. Historically at Marshall Space Flight Center, CHO-THERM@ 1671 has primarily been used for applications where an interface material was deemed necessary. However, there have been numerous alternatives come on the market in recent years. It was decided that a number of these materials should be tested against each other to see if there were better performing alternatives. The tests were done strictly to compare the thermal performance of the materials relative to each other under repeatable conditions and they do not take into consideration other design issues such as off-gassing, electrical conduction or isolation, etc. This paper details the materials tested, test apparatus, procedures, and results of these tests.

Actively Controlled Shaft Seals for Aerospace Applications

NASA Technical Reports Server (NTRS)

Salant, Richard F.; Wolff, Paul

1995-01-01

This study experimentally investigates an actively controlled mechanical seal for aerospace applications. The seal of interest is a gas seal, which is considerably more compact than previous actively controlled mechanical seals that were developed for industrial use. In a mechanical seal, the radial convergence of the seal interface has a primary effect on the film thickness. Active control of the film thickness is established by controlling the radial convergence of the seal interface with a piezoelectric actuator. An actively controlled mechanical seal was initially designed and evaluated using a mathematical model. Based on these results, a seal was fabricated and tested under laboratory conditions. The seal was tested with both helium and air, at rotational speeds up to 3770 rad/sec, and at sealed pressures as high as 1.48 x 10(exp 6) Pa. The seal was operated with both manual control and with a closed-loop control system that used either the leakage rate or face temperature as the feedback. The output of the controller was the voltage applied to the piezoelectric actuator. The seal operated successfully for both short term tests (less than one hour) and for longer term tests (four hours) with a closed-loop control system. The leakage rates were typically 5-15 slm (standard liters per minute), and the face temperatures were generally maintained below 100C. When leakage rate was used as the feedback signal, the setpoint leakage rate was typically maintained within 1 slm. However, larger deviations occurred during sudden changes in sealed pressure. When face temperature was used as the feedback signal, the setpoint face temperature was generally maintained within 3 C, with larger deviations occurring when the sealed pressure changes suddenly. the experimental results were compared to the predictions from the mathematical model. The model was successful in predicting the trends in leakage rate that occurred as the balance ratio and sealed pressure changed, although the leakage rates were not quantitatively predicted with a high degree of accuracy. This model could be useful in providing valuable design information for future actively controlled mechanical seals.

The effect of temperature, matrix alloying and substrate coatings on wettability and shear strength of Al/Al2O3 couples

NASA Astrophysics Data System (ADS)

Sobczak, N.; Ksiazek, M.; Radziwill, W.; Asthana, R.; Mikulowski, B.

2004-03-01

A fresh approach has been advanced to examine in the Al/Al2O3 system the effects of temperature, alloying of Al with Ti or Sn, and Ti and Sn coatings on the substrate, on contact angles measured using a sessile-drop test, and on interface strength measured using a modified push-off test that allows shearing of solidified droplets with less than 90 deg contact angle. In the modified test, the solidified sessile-drop samples are bisected perpendicular to the drop/Al2O3 interface at the midplane of the contact circle to obtain samples that permit bond strength measurement by stress application to the flat surface of the bisected couple. The test results show that interface strength is strongly influenced by the wetting properties; low contact angles correspond to high interface strength, which also exhibits a strong temperature dependence. An increase in the wettability test temperature led to an increase in the interface strength in the low-temperature range where contact angles were large and wettability was poor. The room-temperature shear tests conducted on thermally cycled sessile-drop test specimens revealed the effect of chemically formed interfacial oxides; a weakening of the thermally cycled Al/Al2O3 interface was caused under the following conditions: (1) slow contact heating and short contact times in the wettability test, and (2) fast contact heating and longer contact times. The addition of 6 wt pct Ti or 7 wt pct Sn to Al only marginally influenced the contact angle and interfacial shear strength. However, Al2O3 substrates having thin (<1 µm) Ti coatings yielded relatively low contact angles and high bond strength, which appears to be related to the dissolution of the coating in Al and formation of a favorable interface structure.

Mechanical fatigue resistance of an implantable branched lead system for a distributed set of longitudinal intrafascicular electrodes

NASA Astrophysics Data System (ADS)

Pena, A. E.; Kuntaegowdanahalli, S. S.; Abbas, J. J.; Patrick, J.; Horch, K. W.; Jung, R.

2017-12-01

Objective. A neural interface system has been developed that consists of an implantable stimulator/recorder can with a 15-electrode lead that trifurcates into three bundles of five individual wire longitudinal intrafascicular electrodes. This work evaluated the mechanical fatigue resistance of the branched lead and distributed electrode system under conditions designed to mimic anticipated strain profiles that would be observed after implantation in the human upper arm. Approach. Custom test setups and procedures were developed to apply linear or angular strain at four critical stress riser points on the lead and electrode system. Each test was performed to evaluate fatigue under a high repetition/low amplitude paradigm designed to test the effects of arm movement on the leads during activities such as walking, or under a low repetition/high amplitude paradigm designed to test the effects of more strenuous upper arm activities. The tests were performed on representative samples of the implantable lead system for human use. The specimens were fabricated using procedures equivalent to those that will be used during production of human-use implants. Electrical and visual inspections of all test specimens were performed before and after the testing procedures to assess lead integrity. Main results. Measurements obtained before and after applying repetitive strain indicated that all test specimens retained electrical continuity and that electrical impedance remained well below pre-specified thresholds for detection of breakage. Visual inspection under a microscope at 10×  magnification did not reveal any signs of damage to the wires or silicone sheathing at the stress riser points. Significance. These results demonstrate that the branched lead of this implantable neural interface system has sufficient mechanical fatigue resistance to withstand strain profiles anticipated when the system is implanted in an arm. The novel test setups and paradigms may be useful in testing other lead systems.

Asteroid Redirect Crewed Mission Space Suit and EVA System Maturation

NASA Technical Reports Server (NTRS)

Bowie, Jonathan T.; Kelly, Cody; Buffington, Jesse; Watson, Richard D.

2015-01-01

The Asteroid Redirect Crewed Mission (ARCM) requires a Launch/Entry/Abort (LEA) suit capability and short duration Extra Vehicular Activity (EVA) capability from the Orion spacecraft. For this mission, the pressure garment that was selected, for both functions, is the Modified Advanced Crew Escape Suit (MACES) with EVA enhancements and the life support option that was selected is the Exploration Portable Life Support System (PLSS). The proposed architecture was found to meet the mission constraints, but much more work is required to determine the details of the required suit upgrades, the integration with the PLSS, and the rest of the tools and equipment required to accomplish the mission. This work has continued over the last year to better define the operations and hardware maturation of these systems. EVA simulations have been completed in the NBL and interfacing options have been prototyped and analyzed with testing planned for late 2014. For NBL EVA simulations, in 2013, components were procured to allow in-house build up for four new suits with mobility enhancements built into the arms. Boots outfitted with clips that fit into foot restraints have also been added to the suit and analyzed for possible loads. Major suit objectives accomplished this year in testing include: evaluation of mobility enhancements, ingress/egress of foot restraint, use of foot restraint for worksite stability, ingress/egress of Orion hatch with PLSS mockup, and testing with two crew members in the water at one time to evaluate the crew's ability to help one another. Major tool objectives accomplished this year include using various other methods for worksite stability, testing new methods for asteroid geologic sampling and improving the fidelity of the mockups and crew equipment. These tests were completed on a medium fidelity capsule mockup, asteroid vehicle mockup, and asteroid mockups that were more accurate for an asteroid type EVA than previous tests. Another focus was the design and fabrication of the interface between the MACES and the PLSS. The MACES was not designed to interface with a PLSS, hence an interface kit must accommodate the unique design qualities of the MACES and provide the necessary life support function connections to the PLSS. A prototype interface kit for MACES to PLSS has been designed and fabricated. Unmanned and manned testing of the interface will show the usability of the kit while wearing a MACES. The testing shows viability of the kit approach as well as the operations concept. The design will be vetted through suit and PLSS experts and, with the findings from the testing, the best path forward will be determined. As the Asteroid Redirect Mission matures, the suit/life support portion of the mission will mature along with it and EVA Tools & Equipment can be iterated to accommodate the overall mission objectives and compromises inherent in EVA Suit optimization. The goal of the EVA architecture for ARCM is to continue to build on the previously developed technologies and lessons learned, and accomplish the ARCM EVAs while providing a stepping stone to future missions and destinations.

Multiple Non-Equivalent Interfaces Mediate Direct Activation of GABAA Receptors by Propofol.

PubMed

Eaton, Megan M; Germann, Allison L; Arora, Ruby; Cao, Lily Q; Gao, Xiaoyi; Shin, Daniel J; Wu, Albert; Chiara, David C; Cohen, Jonathan B; Steinbach, Joe Henry; Evers, Alex S; Akk, Gustav

2016-01-01

Propofol is a sedative agent that at clinical concentrations acts by allosterically activating or potentiating the γ-aminobutyric acid type A (GABAA) receptor. Mutational, modeling, and photolabeling studies with propofol and its analogues have identified potential interaction sites in the transmembrane domain of the receptor. At the &quot;+&quot; of the β subunit, in the β-α interface, meta-azipropofol labels the M286 residue in the third transmembrane domain. Substitution of this residue with tryptophan results in loss of potentiation by propofol. At the &quot;-&quot; side of the β subunit, in the α-β interface (or β-β interface, in the case of homomeric β receptors), ortho-propofol diazirine labels the H267 residue in the second transmembrane domain. Structural modeling indicates that the β(H267) residue lines a cavity that docks propofol with favorable interaction energy. We used two-electrode voltage clamp to determine the functional effects of mutations to the "+" and "-" sides of the β subunit on activation of the α1β3 GABAA receptor by propofol. We found that while the individual mutations had a small effect, the combination of the M286W mutation with tryptophan mutations of selected residues at the α-β interface leads to strong reduction in gating efficacy for propofol. We conclude that α1β3 GABAA receptors can be activated by propofol interactions with the β-β, α-β, and β-α interfaces, where distinct, non-equivalent regions control channel gating. Any interface can mediate activation, hence substitutions at all interfaces are required for loss of activation by propofol.

Multiple Non-Equivalent Interfaces Mediate Direct Activation of GABAA Receptors by Propofol

PubMed Central

Eaton, Megan M.; Germann, Allison L.; Arora, Ruby; Cao, Lily Q.; Gao, Xiaoyi; Shin, Daniel J.; Wu, Albert; Chiara, David C.; Cohen, Jonathan B.; Steinbach, Joe Henry; Evers, Alex S.; Akk, Gustav

2016-01-01

Abstract: Background Propofol is a sedative agent that at clinical concentrations acts by allosterically activating or potentiating the γ-aminobutyric acid type A (GABAA) receptor. Mutational, modeling, and photolabeling studies with propofol and its analogues have identified potential interaction sites in the transmembrane domain of the receptor. At the “+” of the β subunit, in the β-α interface, meta-azipropofol labels the M286 residue in the third transmembrane domain. Substitution of this residue with tryptophan results in loss of potentiation by propofol. At the “-” side of the β subunit, in the α-β interface (or β-β interface, in the case of homomeric β receptors), ortho-propofol diazirine labels the H267 residue in the second transmembrane domain. Structural modeling indicates that the β(H267) residue lines a cavity that docks propofol with favorable interaction energy. Method We used two-electrode voltage clamp to determine the functional effects of mutations to the 
“+” and “-” sides of the β subunit on activation of the α1β3 GABAA receptor by propofol. Results We found that while the individual mutations had a small effect, the combination of the M286W mutation with tryptophan mutations of selected residues at the α-β interface leads to strong reduction in gating efficacy for propofol. Conclusion We conclude that α1β3 GABAA receptors can be activated by propofol interactions with the β-β, α-β, and β-α interfaces, where distinct, non-equivalent regions control channel gating. Any interface can mediate activation, hence substitutions at all interfaces are required for loss of activation by propofol. PMID:26830963

Attenuation of Phosphorylation-dependent Activation of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) by Disease-causing Mutations at the Transmission Interface*

PubMed Central

Chin, Stephanie; Yang, Donghe; Miles, Andrew J.; Eckford, Paul D. W.; Molinski, Steven; Wallace, B. A.; Bear, Christine E.

2017-01-01

Cystic fibrosis transmembrane conductance regulator (CFTR) is a multidomain membrane protein that functions as a phosphorylation-regulated anion channel. The interface between its two cytosolic nucleotide binding domains and coupling helices conferred by intracellular loops extending from the channel pore domains has been referred to as a transmission interface and is thought to be critical for the regulated channel activity of CFTR. Phosphorylation of the regulatory domain of CFTR by protein kinase A (PKA) is required for its channel activity. However, it was unclear if phosphorylation modifies the transmission interface. Here, we studied purified full-length CFTR protein using spectroscopic techniques to determine the consequences of PKA-mediated phosphorylation. Synchrotron radiation circular dichroism spectroscopy confirmed that purified full-length wild-type CFTR is folded and structurally responsive to phosphorylation. Intrinsic tryptophan fluorescence studies of CFTR showed that phosphorylation reduced iodide-mediated quenching, consistent with an effect of phosphorylation in burying tryptophans at the transmission interface. Importantly, the rate of phosphorylation-dependent channel activation was compromised by the introduction of disease-causing mutations in either of the two coupling helices predicted to interact with nucleotide binding domain 1 at the interface. Together, these results suggest that phosphorylation modifies the interface between the catalytic and pore domains of CFTR and that this modification facilitates CFTR channel activation. PMID:28003367

STS-87 crew participates in Crew Equipment Interface Test

NASA Technical Reports Server (NTRS)

1997-01-01

Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center are STS-87 crew members, assisted by Glenda Laws, extravehicular activity (EVA) coordinator, Johnson Space Center. Standing behind Laws are Takao Doi, Ph.D., of the National Space Development Agency of Japan, and Winston Scott, both mission specialists on STS-87. The STS-87 mission will be the fourth United States Microgravity Payload and flight of the Spartan-201 deployable satellite. During the mission, scheduled for a Nov. 19 liftoff from KSC, Dr. Doi and Scott will both perform spacewalks.

Classifying BCI signals from novice users with extreme learning machine

NASA Astrophysics Data System (ADS)

Rodríguez-Bermúdez, Germán; Bueno-Crespo, Andrés; José Martinez-Albaladejo, F.

2017-07-01

Brain computer interface (BCI) allows to control external devices only with the electrical activity of the brain. In order to improve the system, several approaches have been proposed. However it is usual to test algorithms with standard BCI signals from experts users or from repositories available on Internet. In this work, extreme learning machine (ELM) has been tested with signals from 5 novel users to compare with standard classification algorithms. Experimental results show that ELM is a suitable method to classify electroencephalogram signals from novice users.

10 CFR Appendix B to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Freezers

Code of Federal Regulations, 2014 CFR

2014-01-01

... factor. 1.2 “Anti-sweat heater” means a device incorporated into the design of a freezer to prevent the accumulation of moisture on exterior or interior surfaces of the cabinet. 1.3 “Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat...

Testing the Vibrational Theory of Olfaction: A Bio-Organic Chemistry Laboratory Experiment Using Hooke's Law and Chirality

ERIC Educational Resources Information Center

Muthyala, Rajeev S.; Butani, Deepali; Nelson, Michelle; Tran, Kiet

2017-01-01

Sense of smell is one of the important senses that enables us to interact with our environment. The molecular basis of olfactory signal transduction is a fascinating area for organic chemistry educators to explore in terms of developing undergraduate laboratory activities at the interface of chemistry and biology. In this paper, a guided-inquiry…

Development of a Multi-Behavioral mHealth App for Women Smokers.

PubMed

Armin, Julie; Johnson, Thienne; Hingle, Melanie; Giacobbi, Peter; Gordon, Judith S

2017-02-01

This article describes the development of the See Me Smoke-Free™ (SMSF) mobile health application, which uses guided imagery to support women in smoking cessation, eating a healthy diet, and increasing physical activity. Focus group discussions, with member checks, were conducted to refine the intervention content and app user interface. Data related to the context of app deployment were collected via user testing sessions and internal quality control testing, which identified and addressed functionality issues, content problems, and bugs. Interactive app features include playback of guided imagery audio files, notification pop-ups, award-sharing on social media, a tracking calendar, content resources, and direct call to the local tobacco quitline. Focus groups helped design the user interface and identified several themes for incorporation into app content, including positivity, the rewards of smoking cessation, and the integrated benefits of maintaining a healthy lifestyle. User testing improved app functionality and usability on many Android phone models. Changes to the app content and function were made iteratively by the development team as a result of focus group and user testing. Despite extensive internal and user testing, unanticipated data collection and reporting issues emerged during deployment due not only to the variety of Android software and hardware but also to individual phone settings and use.

Flexible microelectrode array for interfacing with the surface of neural ganglia

NASA Astrophysics Data System (ADS)

Sperry, Zachariah J.; Na, Kyounghwan; Parizi, Saman S.; Chiel, Hillel J.; Seymour, John; Yoon, Euisik; Bruns, Tim M.

2018-06-01

Objective. The dorsal root ganglia (DRG) are promising nerve structures for sensory neural interfaces because they provide centralized access to primary afferent cell bodies and spinal reflex circuitry. In order to harness this potential, new electrode technologies are needed which take advantage of the unique properties of DRG, specifically the high density of neural cell bodies at the dorsal surface. Here we report initial in vivo results from the development of a flexible non-penetrating polyimide electrode array interfacing with the surface of ganglia. Approach. Multiple layouts of a 64-channel iridium electrode (420 µm2) array were tested, with pitch as small as 25 µm. The buccal ganglia of invertebrate sea slug Aplysia californica were used to develop handling and recording techniques with ganglionic surface electrode arrays (GSEAs). We also demonstrated the GSEA’s capability to record single- and multi-unit activity from feline lumbosacral DRG related to a variety of sensory inputs, including cutaneous brushing, joint flexion, and bladder pressure. Main results. We recorded action potentials from a variety of Aplysia neurons activated by nerve stimulation, and units were observed firing simultaneously on closely spaced electrode sites. We also recorded single- and multi-unit activity associated with sensory inputs from feline DRG. We utilized spatial oversampling of action potentials on closely-spaced electrode sites to estimate the location of neural sources at between 25 µm and 107 µm below the DRG surface. We also used the high spatial sampling to demonstrate a possible spatial sensory map of one feline’s DRG. We obtained activation of sensory fibers with low-amplitude stimulation through individual or groups of GSEA electrode sites. Significance. Overall, the GSEA has been shown to provide a variety of information types from ganglia neurons and to have significant potential as a tool for neural mapping and interfacing.

Role of additives in formation of solid-electrolyte interfaces on carbon electrodes and their effect on high-voltage stability.

PubMed

Qu, Weiguo; Dorjpalam, Enkhtuvshin; Rajagopalan, Ramakrishnan; Randall, Clive A

2014-04-01

The in situ modification of a lithium hexafluorophosphate-based electrolyte using a molybdenum oxide catalyst and small amount of water (1 vol %) yields hydrolysis products such as mono-, di-, and alkylfluorophosphates. The electrochemical stability of ultrahigh-purity, high-surface-area carbon electrodes derived from polyfurfuryl alcohol was tested using the modified electrolyte. Favorable modification of the solid electrolyte interface (SEI) layer on the activated carbon electrode increased the cyclable electrochemical voltage window (4.8-1.2 V vs. Li/Li(+)). The chemical modification of the SEI layer induced by electrolyte additives was characterized by using X-ray photoelectron spectroscopy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

KSC-00pp1762

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Commander Ken Cockrell conducts window inspection, checking for leaks, in the cockpit of Atlantis. He and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC-00pp1769

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- The STS-98 crew looks over components of the equipment already installed in the payload bay of orbiter Atlantis, which is in the Orbiter Processing Facility bay 3. The crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1765

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Pilot Mark Polansky inspects the window in the cockpit of Atlantis. He and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1769

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- The STS-98 crew looks over components of the equipment already installed in the payload bay of orbiter Atlantis, which is in the Orbiter Processing Facility bay 3. The crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1762

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Commander Ken Cockrell conducts window inspection, checking for leaks, in the cockpit of Atlantis. He and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1767

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- Working on the Orbiter Docking System of orbiter Atlantis are Mission Specialists Tom Jones (leaning over) and Robert Curbeam. They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC-00pp1765

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Pilot Mark Polansky inspects the window in the cockpit of Atlantis. He and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC-00pp1767

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- Working on the Orbiter Docking System of orbiter Atlantis are Mission Specialists Tom Jones (leaning over) and Robert Curbeam. They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

Experiments on reduction of propeller induced interior noise by active control of cylinder vibration

NASA Technical Reports Server (NTRS)

Fuller, C. R.; Jones, J. D.

1987-01-01

The feasibility of reducing interior noise caused by advanced turbo propellers by controlling the vibration of aircraft fuselages was investigated by performing experiments in an anechoic chamber with an aircraft model test rig and apparatus. It was found that active vibration control provides reasonable global attenuation of interior noise levels for the cases of resonant (at 576 Hz) and forced (at 708 Hz) system response. The controlling mechanism behind the effect is structural-acoustic coupling between the shell and the contained field, termed interface modal filtering.

KSC-07pd2615

NASA Image and Video Library

2007-09-28

KENNEDY SPACE CENTER, FLA. -- In the Orbiter Processing Facility, STS-122 crew members are introduced to part of the LESS. From left are Mission Specialists Stanley Love, Hans Schlegel and Rex Walheim. The crew is at Kennedy to take part in a crew equipment interface test, or CEIT, which helps familiarize them with equipment and payloads for the mission. Among the activities standard to a CEIT are harness training, inspection of the thermal protection system and camera operation for planned extravehicular activities, or EVAs. STS-122 is targeted for launch in December. Photo credit: NASA/Kim Shiflett

Space transportation system payload interface verification

NASA Technical Reports Server (NTRS)

Everline, R. T.

1977-01-01

The paper considers STS payload-interface verification requirements and the capability provided by STS to support verification. The intent is to standardize as many interfaces as possible, not only through the design, development, test and evaluation (DDT and E) phase of the major payload carriers but also into the operational phase. The verification process is discussed in terms of its various elements, such as the Space Shuttle DDT and E (including the orbital flight test program) and the major payload carriers DDT and E (including the first flights). Five tools derived from the Space Shuttle DDT and E are available to support the verification process: mathematical (structural and thermal) models, the Shuttle Avionics Integration Laboratory, the Shuttle Manipulator Development Facility, and interface-verification equipment (cargo-integration test equipment).

Self-assembled silver nanoparticle films at an air-liquid interface and their applications in SERS and electrochemistry

NASA Astrophysics Data System (ADS)

Wang, Li; Sun, Yujing; Che, Guangbo; Li, Zhuang

2011-06-01

In this paper, we present a novel technique to prepare silver nanoparticle films by controlling the self-assembly of nanoparticles at an air-liquid interface. In an ethanol-water phase, silver nanoparticles were prepared by reduction of AgNO 3 aqueous solution with NaBH 4 in the presence of cinnamic acid. It was found that the silver nanoparticles in this process could be trapped at the air-liquid interface to form 2-dimensional nanoparticle films. The morphology of nanoparticle films could be controlled by systematic variation of the experimental parameters. It is worth noting that the nanoparticle films could serve as the active substrates for surface-enhanced Raman scattering (SERS). 4-Aminothiophenol (4-ATP) molecule was used as a test probe to investigate the SERS sensitivity of different nanoparticle films. The results indicated that the nanoparticle films showed excellent Raman enhancement effect. Furthermore, the nanoparticle films prepared by our strategy were found to be efficient electrocatalysts for anodic oxidation of formaldehyde in alkaline medium.

Generation of complex motor patterns in american grasshopper via current-controlled thoracic electrical interfacing.

PubMed

Giampalmo, Susan L; Absher, Benjamin F; Bourne, W Tucker; Steves, Lida E; Vodenski, Vassil V; O'Donnell, Peter M; Erickson, Jonathan C

2011-01-01

Micro-air vehicles (MAVs) have attracted attention for their potential application to military applications, environmental sensing, and search and rescue missions. While progress is being made toward fabrication of a completely human-engineered MAV, another promising approach seeks to interface to, and take control of, an insect's nervous system. Cyborg insects take advantage of their innate exquisite loco-motor, navigation, and sensing abilities. Recently, several groups have demonstrated the feasibility of radio-controlled flight in the hawkmoth and beetle via electrical neural interfaces. Here, we report a method for eliciting the "jump" response in the American grasshopper (S. Americana). We found that stimulating the metathoracic T3 ganglion with constant-current square wave pulses with amplitude 186 ± 40 μA and frequency 190 ± 13 Hz reproducibly evoked (≥95% success rate) the desired motor activity in N=3 test subjects. To the best of our knowledge, this is the first report of an insect cyborg with a synchronous neuromuscular system.

Interset: A natural language interface for teleoperated robotic assembly of the EASE space structure

NASA Technical Reports Server (NTRS)

Boorsma, Daniel K.

1989-01-01

A teleoperated robot was used to assemble the Experimental Assembly of Structures in Extra-vehicular activity (EASE) space structure under neutral buoyancy conditions, simulating a telerobot performing structural assembly in the zero gravity of space. This previous work used a manually controlled teleoperator as a test bed for system performance evaluations. From these results several Artificial Intelligence options were proposed. One of these was further developed into a real time assembly planner. The interface for this system is effective in assembling EASE structures using windowed graphics and a set of networked menus. As the problem space becomes more complex and hence the set of control options increases, a natural language interface may prove to be beneficial to supplement the menu based control strategy. This strategy can be beneficial in situations such as: describing the local environment, maintaining a data base of task event histories, modifying a plan or a heuristic dynamically, summarizing a task in English, or operating in a novel situation.

Steered Molecular Dynamics Simulations Predict Conformational Stability of Glutamate Receptors.

PubMed

Musgaard, Maria; Biggin, Philip C

2016-09-26

The stability of protein-protein interfaces can be essential for protein function. For ionotropic glutamate receptors, a family of ligand-gated ion channels vital for normal function of the central nervous system, such an interface exists between the extracellular ligand binding domains (LBDs). In the full-length protein, the LBDs are arranged as a dimer of dimers. Agonist binding to the LBDs opens the ion channel, and briefly after activation the receptor desensitizes. Several residues at the LBD dimer interface are known to modulate desensitization, and conformational changes around these residues are believed to be involved in the state transition. The general hypothesis is that the interface is disrupted upon desensitization, and structural evidence suggests that the disruption might be substantial. However, when cross-linking the central part of this interface, functional data suggest that the receptor can still undergo desensitization, contradicting the hypothesis of major interface disruption. Here, we illustrate how opening the dimer interface using steered molecular dynamics (SMD) simulations, and analyzing the work values required, provides a quantitative measure for interface stability. For one subtype of glutamate receptors, which is regulated by ion binding to the dimer interface, we show that opening the interface without ions bound requires less work than with ions present, suggesting that ion binding indeed stabilizes the interface. Likewise, for interface mutants with longer-lived active states, the interface is more stable, while the work required to open the interface is reduced for less active mutants. Moreover, a cross-linked mutant can still undergo initial interface opening motions similar to the native receptor and at similar energetic cost. Thus, our results support that interface opening is involved in desensitization. Furthermore, they provide reconciliation of apparently opposing data and demonstrate that SMD simulations can give relevant biological insight into longer time scale processes without the need for expensive calculations.

Photo-activated luminescence sensor and method of detecting trichloroethylene and related volatile organochloride compounds

DOEpatents

Dinh, T.V.

1996-06-11

A sensor for detecting trichloroethylene and related volatile organochloride compounds uses a photo-activator that produces a photo-product complex with the contaminant. Characteristics of the light emitted from the complex will indicate the presence of the contaminant. A probe containing the photo-activator has an excitation light interface and a contaminant interface. One particular embodiment uses a porous membrane as the contaminant interface, so that the contaminant can migrate there through to the photo-activator and thereby form the complex. 23 figs.

Space Shuttle Solid Rocket Booster decelerator subsystem - Air drop test vehicle/B-52 design

NASA Technical Reports Server (NTRS)

Runkle, R. E.; Drobnik, R. F.

1979-01-01

The air drop development test program for the Space Shuttle Solid Rocket Booster Recovery System required the design of a large drop test vehicle that would meet all the stringent requirements placed on it by structural loads, safety considerations, flight recovery system interfaces, and sequence. The drop test vehicle had to have the capability to test the drogue and the three main parachutes both separately and in the total flight deployment sequence and still be low-cost to fit in a low-budget development program. The design to test large ribbon parachutes to loads of 300,000 pounds required the detailed investigation and integration of several parameters such as carrier aircraft mechanical interface, drop test vehicle ground transportability, impact point ground penetration, salvageability, drop test vehicle intelligence, flight design hardware interfaces, and packaging fidelity.

Microstructural Characterization of the U-9.1Mo Fuel/AA6061 Cladding Interface in Friction-Bonded Monolithic Fuel Plates Irradiated in the RERTR-6 Experiment

NASA Astrophysics Data System (ADS)

Keiser, Dennis D.; Jue, Jan-Fong; Miller, Brandon; Gan, Jian; Robinson, Adam; Medvedev, Pavel; Madden, James; Wachs, Dan; Clark, Curtis; Meyer, Mitch

2015-09-01

Low-enrichment (235U < 20 pct) U-Mo monolithic fuel is being developed for use in research and test reactors. The earliest design for this fuel that was investigated via reactor testing consisted of a nominally U-10Mo fuel foil encased in AA6061 (Al-6061) cladding. For a fuel design to be deemed adequate for final use in a reactor, it must maintain dimensional stability and retain fission products throughout irradiation, which means that there must be good integrity at the fuel foil/cladding interface. To investigate the nature of the fuel/cladding interface for this fuel type after irradiation, fuel plates were fabricated using a friction bonding process, tested in INL's advanced test reactor (ATR), and then subsequently characterized using optical metallography, scanning electron microscopy, and transmission electron microscopy. Results of this characterization showed that the fuel/cladding interaction layers present at the U-Mo fuel/AA6061 cladding interface after fabrication became amorphous during irradiation. Up to two main interaction layers, based on composition, could be found at the fuel/cladding interface, depending on location. After irradiation, an Al-rich layer contained very few fission gas bubbles, but did exhibit Xe enrichment near the AA6061 cladding interface. Another layer, which contained more Si, had more observable fission gas bubbles. In the samples produced using a focused ion beam at the interaction zone/AA6061 cladding interface, possible indications of porosity/debonding were found, which suggested that the interface in this location is relatively weak.

Feasibility of task-specific brain-machine interface training for upper-extremity paralysis in patients with chronic hemiparetic stroke.

PubMed

Nishimoto, Atsuko; Kawakami, Michiyuki; Fujiwara, Toshiyuki; Hiramoto, Miho; Honaga, Kaoru; Abe, Kaoru; Mizuno, Katsuhiro; Ushiba, Junichi; Liu, Meigen

2018-01-10

Brain-machine interface training was developed for upper-extremity rehabilitation for patients with severe hemiparesis. Its clinical application, however, has been limited because of its lack of feasibility in real-world rehabilitation settings. We developed a new compact task-specific brain-machine interface system that enables task-specific training, including reach-and-grasp tasks, and studied its clinical feasibility and effectiveness for upper-extremity motor paralysis in patients with stroke. Prospective beforeâ€"after study. Twenty-six patients with severe chronic hemiparetic stroke. Participants were trained with the brain-machine interface system to pick up and release pegs during 40-min sessions and 40 min of standard occupational therapy per day for 10 days. Fugl-Meyer upper-extremity motor (FMA) and Motor Activity Log-14 amount of use (MAL-AOU) scores were assessed before and after the intervention. To test its feasibility, 4 occupational therapists who operated the system for the first time assessed it with the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST) 2.0. FMA and MAL-AOU scores improved significantly after brain-machine interface training, with the effect sizes being medium and large, respectively (p<0.01, d=0.55; p<0.01, d=0.88). QUEST effectiveness and safety scores showed feasibility and satisfaction in the clinical setting. Our newly developed compact brain-machine interface system is feasible for use in real-world clinical settings.

Integrating an internet-mediated walking program into family medicine clinical practice: a pilot feasibility study.

PubMed

Goodrich, David E; Buis, Lorraine R; Janney, Adrienne W; Ditty, Megan D; Krause, Christine W; Zheng, Kai; Sen, Ananda; Strecher, Victor J; Hess, Michael L; Piette, John D; Richardson, Caroline R

2011-06-24

Regular participation in physical activity can prevent many chronic health conditions. Computerized self-management programs are effective clinical tools to support patient participation in physical activity. This pilot study sought to develop and evaluate an online interface for primary care providers to refer patients to an Internet-mediated walking program called Stepping Up to Health (SUH) and to monitor participant progress in the program. In Phase I of the study, we recruited six pairs of physicians and medical assistants from two family practice clinics to assist with the design of a clinical interface. During Phase II, providers used the developed interface to refer patients to a six-week pilot intervention. Provider perspectives were assessed regarding the feasibility of integrating the program into routine care. Assessment tools included quantitative and qualitative data gathered from semi-structured interviews, surveys, and online usage logs. In Phase I, 13 providers used SUH and participated in two interviews. Providers emphasized the need for alerts flagging patients who were not doing well and the ability to review participant progress. Additionally, providers asked for summary views of data across all enrolled clinic patients as well as advertising materials for intervention recruitment. In response to this input, an interface was developed containing three pages: 1) a recruitment page, 2) a summary page, and 3) a detailed patient page. In Phase II, providers used the interface to refer 139 patients to SUH and 37 (27%) enrolled in the intervention. Providers rarely used the interface to monitor enrolled patients. Barriers to regular use of the intervention included lack of integration with the medical record system, competing priorities, patient disinterest, and physician unease with exercise referrals. Intention-to-treat analyses showed that patients increased walking by an average of 1493 steps/day from pre- to post-intervention (t = (36) = 4.13, p < 0.01). Providers successfully referred patients using the SUH provider interface, but were less willing to monitor patient compliance in the program. Patients who completed the program significantly increased their step counts. Future research is needed to test the effectiveness of integrating SUH with clinical information systems over a longer evaluation period.

Validation of Force Limited Vibration Testing at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Rice, Chad; Buehrle, Ralph D.

2003-01-01

Vibration tests were performed to develop and validate the forced limited vibration testing capability at the NASA Langley Research Center. The force limited vibration test technique has been utilized at the Jet Propulsion Laboratory and other NASA centers to provide more realistic vibration test environments for aerospace flight hardware. In standard random vibration tests, the payload is mounted to a rigid fixture and the interface acceleration is controlled to a specified level based on a conservative estimate of the expected flight environment. In force limited vibration tests, both the acceleration and force are controlled at the mounting interface to compensate for differences between the flexible flight mounting and rigid test fixture. This minimizes the over test at the payload natural frequencies and results in more realistic forces being transmitted at the mounting interface. Force and acceleration response data was provided by NASA Goddard Space Flight Center for a test article that was flown in 1998 on a Black Brant sounding rocket. The measured flight interface acceleration data was used as the reference acceleration spectrum. Using this acceleration spectrum, three analytical methods were used to estimate the force limits. Standard random and force limited vibration tests were performed and the results are compared with the flight data.

Development of a Regenerative Peripheral Nerve Interface for Control of a Neuroprosthetic Limb.

PubMed

Urbanchek, Melanie G; Kung, Theodore A; Frost, Christopher M; Martin, David C; Larkin, Lisa M; Wollstein, Adi; Cederna, Paul S

2016-01-01

Background. The purpose of this experiment was to develop a peripheral nerve interface using cultured myoblasts within a scaffold to provide a biologically stable interface while providing signal amplification for neuroprosthetic control and preventing neuroma formation. Methods. A Regenerative Peripheral Nerve Interface (RPNI) composed of a scaffold and cultured myoblasts was implanted on the end of a divided peroneal nerve in rats (n = 25). The scaffold material consisted of either silicone mesh, acellular muscle, or acellular muscle with chemically polymerized poly(3,4-ethylenedioxythiophene) conductive polymer. Average implantation time was 93 days. Electrophysiological tests were performed at endpoint to determine RPNI viability and ability to transduce neural signals. Tissue samples were examined using both light microscopy and immunohistochemistry. Results. All implanted RPNIs, regardless of scaffold type, remained viable and displayed robust vascularity. Electromyographic activity and stimulated compound muscle action potentials were successfully recorded from all RPNIs. Physiologic efferent motor action potentials were detected from RPNIs in response to sensory foot stimulation. Histology and transmission electron microscopy revealed mature muscle fibers, axonal regeneration without neuroma formation, neovascularization, and synaptogenesis. Desmin staining confirmed the preservation and maturation of myoblasts within the RPNIs. Conclusions. RPNI demonstrates significant myoblast maturation, innervation, and vascularization without neuroma formation.

Control Strategies for the DAB Based PV Interface System

PubMed Central

El-Helw, Hadi M.; Al-Hasheem, Mohamed; Marei, Mostafa I.

2016-01-01

This paper presents an interface system based on the Dual Active Bridge (DAB) converter for Photovoltaic (PV) arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the DAB converter. The Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is utilized to set the reference of the PV terminal voltage. The second strategy presented in this paper employs the Artificial Neural Network (ANN) to directly set the phase shift angle of the DAB converter that results in harvesting maximum power. This feed-forward strategy overcomes the stability issues of the feedback strategy. The proposed PV interface systems are modeled and simulated using MATLAB/SIMULINK and the EMTDC/PSCAD software packages. The simulation results reveal accurate and fast response of the proposed systems. The dynamic performance of the proposed feed-forward strategy outdoes that of the feedback strategy in terms of accuracy and response time. Moreover, an experimental prototype is built to test and validate the proposed PV interface system. PMID:27560138

Optical mass memory system (AMM-13). AMM/DBMS interface control document

NASA Technical Reports Server (NTRS)

Bailey, G. A.

1980-01-01

The baseline for external interfaces of a 10 to the 13th power bit, optical archival mass memory system (AMM-13) is established. The types of interfaces addressed include data transfer; AMM-13, Data Base Management System, NASA End-to-End Data System computer interconnect; data/control input and output interfaces; test input data source; file management; and facilities interface.

Improved usability of a multi-infusion setup using a centralized control interface: A task-based usability test

PubMed Central

Cnossen, Fokie; Dieperink, Willem; Bult, Wouter; de Smet, Anne Marie; Touw, Daan J.; Nijsten, Maarten W.

2017-01-01

The objective of this study was to assess the usability benefits of adding a bedside central control interface that controls all intravenous (IV) infusion pumps compared to the conventional individual control of multiple infusion pumps. Eighteen dedicated ICU nurses volunteered in a between-subjects task-based usability test. A newly developed central control interface was compared to conventional control of multiple infusion pumps in a simulated ICU setting. Task execution time, clicks, errors and questionnaire responses were evaluated. Overall the central control interface outperformed the conventional control in terms of fewer user actions (40±3 vs. 73±20 clicks, p<0.001) and fewer user errors (1±1 vs. 3±2 errors, p<0.05), with no difference in task execution times (421±108 vs. 406±119 seconds, not significant). Questionnaires indicated a significant preference for the central control interface. Despite being novice users of the central control interface, ICU nurses displayed improved performance with the central control interface compared to the conventional interface they were familiar with. We conclude that the new user interface has an overall better usability than the conventional interface. PMID:28800617

Improved usability of a multi-infusion setup using a centralized control interface: A task-based usability test.

PubMed

Doesburg, Frank; Cnossen, Fokie; Dieperink, Willem; Bult, Wouter; de Smet, Anne Marie; Touw, Daan J; Nijsten, Maarten W

2017-01-01

The objective of this study was to assess the usability benefits of adding a bedside central control interface that controls all intravenous (IV) infusion pumps compared to the conventional individual control of multiple infusion pumps. Eighteen dedicated ICU nurses volunteered in a between-subjects task-based usability test. A newly developed central control interface was compared to conventional control of multiple infusion pumps in a simulated ICU setting. Task execution time, clicks, errors and questionnaire responses were evaluated. Overall the central control interface outperformed the conventional control in terms of fewer user actions (40±3 vs. 73±20 clicks, p<0.001) and fewer user errors (1±1 vs. 3±2 errors, p<0.05), with no difference in task execution times (421±108 vs. 406±119 seconds, not significant). Questionnaires indicated a significant preference for the central control interface. Despite being novice users of the central control interface, ICU nurses displayed improved performance with the central control interface compared to the conventional interface they were familiar with. We conclude that the new user interface has an overall better usability than the conventional interface.

An implantable integrated low-power amplifier-microelectrode array for Brain-Machine Interfaces.

PubMed

Patrick, Erin; Sankar, Viswanath; Rowe, William; Sanchez, Justin C; Nishida, Toshikazu

2010-01-01

One of the important challenges in designing Brain-Machine Interfaces (BMI) is to build implantable systems that have the ability to reliably process the activity of large ensembles of cortical neurons. In this paper, we report the design, fabrication, and testing of a polyimide-based microelectrode array integrated with a low-power amplifier as part of the Florida Wireless Integrated Recording Electrode (FWIRE) project at the University of Florida developing a fully implantable neural recording system for BMI applications. The electrode array was fabricated using planar micromachining MEMS processes and hybrid packaged with the amplifier die using a flip-chip bonding technique. The system was tested both on bench and in-vivo. Acute and chronic neural recordings were obtained from a rodent for a period of 42 days. The electrode-amplifier performance was analyzed over the chronic recording period with the observation of a noise floor of 4.5 microVrms, and an average signal-to-noise ratio of 3.8.

Scalable Integrated Multi-Mission Support System (SIMSS) Simulator Release 2.0 for GMSEC

NASA Technical Reports Server (NTRS)

Kim, John; Velamuri, Sarma; Casey, Taylor; Bemann, Travis

2012-01-01

Scalable Integrated Multi-Mission Support System (SIMSS) Simulator Release 2.0 software is designed to perform a variety of test activities related to spacecraft simulations and ground segment checks. This innovation uses the existing SIMSS framework, which interfaces with the GMSEC (Goddard Mission Services Evolution Center) Application Programming Interface (API) Version 3.0 message middleware, and allows SIMSS to accept GMSEC standard messages via the GMSEC message bus service. SIMSS is a distributed, component-based, plug-and-play client-server system that is useful for performing real-time monitoring and communications testing. SIMSS runs on one or more workstations, and is designed to be user-configurable, or to use predefined configurations for routine operations. SIMSS consists of more than 100 modules that can be configured to create, receive, process, and/or transmit data. The SIMSS/GMSEC innovation is intended to provide missions with a low-cost solution for implementing their ground systems, as well as to significantly reduce a mission s integration time and risk.

Attachment of second harmonic-active moiety to molecules for detection of molecules at interfaces

DOEpatents

Salafsky, Joshua S.; Eisenthal, Kenneth B.

2005-10-11

This invention provides methods of detecting molecules at an interface, which comprise labeling the molecules with a second harmonic-active moiety and detecting the labeled molecules at the interface using a surface selective technique. The invention also provides methods for detecting a molecule in a medium and for determining the orientation of a molecular species within a planar surface using a second harmonic-active moiety and a surface selective technique.

Coordinated Noninvasive Studies (CNS) Project

NASA Astrophysics Data System (ADS)

Lauter, Judith

1988-11-01

Research activities during this period include: data collection related to the interface between complex-sound production and perception, specifically, studies on speech acoustics including two experiments on voice-onset-time variability in productions by speakers of several languages, and a series on acoustical characteristics of emotional expression; data collection regarding individual differences in the effect of stimulus characteristic on relative ear advantages; continuing data analysis and new collections documenting individual differences in auditory evoked potentials, with details related to auditory-systems asymmetries preliminary tests regarding the match between behavioral measures of relative ear advantages and quantitative-electroencephalographic asymmetries observed during auditory stimulation; pilot testing using a combination of Nuclear Magnetic Resonance's (NMR) anatomical-imaging and chemical-spectral-analysis capabilities to study physiological activation in the human brain.

Interfacing and Verifying ALHAT Safe Precision Landing Systems with the Morpheus Vehicle

NASA Technical Reports Server (NTRS)

Carson, John M., III; Hirsh, Robert L.; Roback, Vincent E.; Villalpando, Carlos; Busa, Joseph L.; Pierrottet, Diego F.; Trawny, Nikolas; Martin, Keith E.; Hines, Glenn D.

2015-01-01

The NASA Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project developed a suite of prototype sensors to enable autonomous and safe precision landing of robotic or crewed vehicles under any terrain lighting conditions. Development of the ALHAT sensor suite was a cross-NASA effort, culminating in integration and testing on-board a variety of terrestrial vehicles toward infusion into future spaceflight applications. Terrestrial tests were conducted on specialized test gantries, moving trucks, helicopter flights, and a flight test onboard the NASA Morpheus free-flying, rocket-propulsive flight-test vehicle. To accomplish these tests, a tedious integration process was developed and followed, which included both command and telemetry interfacing, as well as sensor alignment and calibration verification to ensure valid test data to analyze ALHAT and Guidance, Navigation and Control (GNC) performance. This was especially true for the flight test campaign of ALHAT onboard Morpheus. For interfacing of ALHAT sensors to the Morpheus flight system, an adaptable command and telemetry architecture was developed to allow for the evolution of per-sensor Interface Control Design/Documents (ICDs). Additionally, individual-sensor and on-vehicle verification testing was developed to ensure functional operation of the ALHAT sensors onboard the vehicle, as well as precision-measurement validity for each ALHAT sensor when integrated within the Morpheus GNC system. This paper provides some insight into the interface development and the integrated-systems verification that were a part of the build-up toward success of the ALHAT and Morpheus flight test campaigns in 2014. These campaigns provided valuable performance data that is refining the path toward spaceflight infusion of the ALHAT sensor suite.

Automating testbed documentation and database access using World Wide Web (WWW) tools

NASA Technical Reports Server (NTRS)

Ames, Charles; Auernheimer, Brent; Lee, Young H.

1994-01-01

A method for providing uniform transparent access to disparate distributed information systems was demonstrated. A prototype testing interface was developed to access documentation and information using publicly available hypermedia tools. The prototype gives testers a uniform, platform-independent user interface to on-line documentation, user manuals, and mission-specific test and operations data. Mosaic was the common user interface, and HTML (Hypertext Markup Language) provided hypertext capability.

Multi-Megawatt-Scale Power-Hardware-in-the-Loop Interface for Testing Ancillary Grid Services by Converter-Coupled Generation: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koralewicz, Przemyslaw J; Gevorgian, Vahan; Wallen, Robert B

Power-hardware-in-the-loop (PHIL) is a simulation tool that can support electrical systems engineers in the development and experimental validation of novel, advanced control schemes that ensure the robustness and resiliency of electrical grids that have high penetrations of low-inertia variable renewable resources. With PHIL, the impact of the device under test on a generation or distribution system can be analyzed using a real-time simulator (RTS). PHIL allows for the interconnection of the RTS with a 7 megavolt ampere (MVA) power amplifier to test multi-megawatt renewable assets available at the National Wind Technology Center (NWTC). This paper addresses issues related to themore » development of a PHIL interface that allows testing hardware devices at actual scale. In particular, the novel PHIL interface algorithm and high-speed digital interface, which minimize the critical loop delay, are discussed.« less

Multi-Megawatt-Scale Power-Hardware-in-the-Loop Interface for Testing Ancillary Grid Services by Converter-Coupled Generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koralewicz, Przemyslaw J; Gevorgian, Vahan; Wallen, Robert B

Power-hardware-in-the-loop (PHIL) is a simulation tool that can support electrical systems engineers in the development and experimental validation of novel, advanced control schemes that ensure the robustness and resiliency of electrical grids that have high penetrations of low-inertia variable renewable resources. With PHIL, the impact of the device under test on a generation or distribution system can be analyzed using a real-time simulator (RTS). PHIL allows for the interconnection of the RTS with a 7 megavolt ampere (MVA) power amplifier to test multi-megawatt renewable assets available at the National Wind Technology Center (NWTC). This paper addresses issues related to themore » development of a PHIL interface that allows testing hardware devices at actual scale. In particular, the novel PHIL interface algorithm and high-speed digital interface, which minimize the critical loop delay, are discussed.« less

Combination of brain-computer interface training and goal-directed physical therapy in chronic stroke: a case report.

PubMed

Broetz, Doris; Braun, Christoph; Weber, Cornelia; Soekadar, Surjo R; Caria, Andrea; Birbaumer, Niels

2010-09-01

There is no accepted and efficient rehabilitation strategy to reduce focal impairments for patients with chronic stroke who lack residual movements. A 67-year-old hemiplegic patient with no active finger extension was trained with a brain-computer interface (BCI) combined with a specific daily life-oriented physiotherapy. The BCI used electrical brain activity (EEG) and magnetic brain activity (MEG) to drive an orthosis and a robot affixed to the patient's affected upper extremity, which enabled him to move the paralyzed arm and hand driven by voluntary modulation of micro-rhythm activity. In addition, the patient practiced goal-directed physiotherapy training. Over 1 year, he completed 3 training blocks. Arm motor function, gait capacities (using Fugl-Meyer Assessment, Wolf Motor Function Test, Modified Ashworth Scale, 10-m walk speed, and goal attainment score), and brain reorganization (functional MRI, MEG) were repeatedly assessed. The ability of hand and arm movements as well as speed and safety of gait improved significantly (mean 46.6%). Improvement of motor function was associated with increased micro-oscillations in the ipsilesional motor cortex. This proof-of-principle study suggests that the combination of BCI training with goal-directed, active physical therapy may improve the motor abilities of chronic stroke patients despite apparent initial paralysis.

Unscented Kalman Filter for Brain-Machine Interfaces

PubMed Central

Li, Zheng; O'Doherty, Joseph E.; Hanson, Timothy L.; Lebedev, Mikhail A.; Henriquez, Craig S.; Nicolelis, Miguel A. L.

2009-01-01

Brain machine interfaces (BMIs) are devices that convert neural signals into commands to directly control artificial actuators, such as limb prostheses. Previous real-time methods applied to decoding behavioral commands from the activity of populations of neurons have generally relied upon linear models of neural tuning and were limited in the way they used the abundant statistical information contained in the movement profiles of motor tasks. Here, we propose an n-th order unscented Kalman filter which implements two key features: (1) use of a non-linear (quadratic) model of neural tuning which describes neural activity significantly better than commonly-used linear tuning models, and (2) augmentation of the movement state variables with a history of n-1 recent states, which improves prediction of the desired command even before incorporating neural activity information and allows the tuning model to capture relationships between neural activity and movement at multiple time offsets simultaneously. This new filter was tested in BMI experiments in which rhesus monkeys used their cortical activity, recorded through chronically implanted multielectrode arrays, to directly control computer cursors. The 10th order unscented Kalman filter outperformed the standard Kalman filter and the Wiener filter in both off-line reconstruction of movement trajectories and real-time, closed-loop BMI operation. PMID:19603074

Analysis of electron transfer processes across liquid/liquid interfaces: estimation of free energy of activation using diffuse boundary model.

PubMed

Harinipriya, S; Sangaranarayanan, M V

2006-01-31

The evaluation of the free energy of activation pertaining to the electron-transfer reactions occurring at liquid/liquid interfaces is carried out employing a diffuse boundary model. The interfacial solvation numbers are estimated using a lattice gas model under the quasichemical approximation. The standard reduction potentials of the redox couples, appropriate inner potential differences, dielectric permittivities, as well as the width of the interface are included in the analysis. The methodology is applied to the reaction between [Fe(CN)6](3-/4-) and [Lu(biphthalocyanine)](3+/4+) at water/1,2-dichloroethane interface. The rate-determining step is inferred from the estimated free energy of activation for the constituent processes. The results indicate that the solvent shielding effect and the desolvation of the reactants at the interface play a central role in dictating the free energy of activation. The heterogeneous electron-transfer rate constant is evaluated from the molar reaction volume and the frequency factor.

Functional interactions at the interface between voltage-sensing and pore domains in the Shaker K(v) channel.

PubMed

Soler-Llavina, Gilberto J; Chang, Tsg-Hui; Swartz, Kenton J

2006-11-22

Voltage-activated potassium (K(v)) channels contain a central pore domain that is partially surrounded by four voltage-sensing domains. Recent X-ray structures suggest that the two domains lack extensive protein-protein contacts within presumed transmembrane regions, but whether this is the case for functional channels embedded in lipid membranes remains to be tested. We investigated domain interactions in the Shaker K(v) channel by systematically mutating the pore domain and assessing tolerance by examining channel maturation, S4 gating charge movement, and channel opening. When mapped onto the X-ray structure of the K(v)1.2 channel the large number of permissive mutations support the notion of relatively independent domains, consistent with crystallographic studies. Inspection of the maps also identifies portions of the interface where residues are sensitive to mutation, an external cluster where mutations hinder voltage sensor activation, and an internal cluster where domain interactions between S4 and S5 helices from adjacent subunits appear crucial for the concerted opening transition.

Ethernet-based test stand for a CAN network

NASA Astrophysics Data System (ADS)

Ziebinski, Adam; Cupek, Rafal; Drewniak, Marek

2017-11-01

This paper presents a test stand for the CAN-based systems that are used in automotive systems. The authors propose applying an Ethernet-based test system that supports the virtualisation of a CAN network. The proposed solution has many advantages compared to classical test beds that are based on dedicated CAN-PC interfaces: it allows the physical constraints associated with the number of interfaces that can be simultaneously connected to a tested system to be avoided, which enables the test time for parallel tests to be shortened; the high speed of Ethernet transmission allows for more frequent sampling of the messages that are transmitted by a CAN network (as the authors show in the experiment results section) and the cost of the proposed solution is much lower than the traditional lab-based dedicated CAN interfaces for PCs.

MPLM Donatello is offloaded at the SLF

NASA Technical Reports Server (NTRS)

2001-01-01

At the Shuttle Landing Facility, cranes help offload the Italian Space Agency's Multi-Purpose Logistics Module Donatello from the Airbus '''Beluga''' air cargo plane. The third of three for the International Space Station, the module will be moved on a transporter to the Space Station Processing Facility for processing. Among the activities for the payload test team are integrated electrical tests with other Station elements in the SSPF, leak tests, electrical and software compatibility tests with the Space Shuttle (using the Cargo Integrated Test equipment) and an Interface Verification Test once the module is installed in the Space Shuttle's payload bay at the launch pad. The most significant mechanical task to be performed on Donatello in the SSPF is the installation and outfitting of the racks for carrying the various experiments and cargo.

Evaluating the Effect of Flow and Interface Type on Pressures Delivered With Bubble CPAP in a Simulated Model.

PubMed

Bailes, Stephanie A; Firestone, Kimberly S; Dunn, Diane K; McNinch, Neil L; Brown, Miraides F; Volsko, Teresa A

2016-03-01

Bubble CPAP, used for spontaneously breathing infants to avoid intubation or postextubation support, can be delivered with different interface types. This study compared the effect that interfaces had on CPAP delivery. We hypothesized that there would be no difference between set and measured levels between interface types. A validated preterm infant nasal airway model was attached to the ASL 5000 breathing simulator. The simulator was programmed to deliver active breathing of a surfactant-deficient premature infant with breathing frequency at 70 breaths/min inspiratory time of 0.30 s, resistance of 150 cm H2O/L/s, compliance of 0.5 mL/cm H2O, tidal volume of 5 mL, and esophageal pressure of -10 cm H2O. Nasal CPAP prongs, size 4030, newborn and infant RAM cannulas were connected to a nasal airway model and a bubble CPAP system. CPAP levels were set at 4, 5, 6, 7, 8, and 9 cm H2O with flows of 6, 8, and 10 L/min each. Measurements were recorded after 1 min of stabilization. The analysis was performed using SAS 9.4. The Kolmogorov-Smirnov test assessed normality of the data. The Friedman test was used to compare non-normally distributed repeated measures. The Wilcoxon signed-rank test was used to conduct post hoc analysis. All tests were 2-sided, and P values of <.05 were considered as indicating significant differences unless otherwise indicated. At lower set CPAP levels, 4-6 cm H2O, measured CPAP dropped precipitously with the nasal prongs with the highest flow setting. At higher CPAP levels, 7-9 cm H2O measured CPAP concomitantly increased as the flow setting increased. Statistically significant differences in set and measured CPAP occurred for all devices across all CPAP levels, with the measured CPAP less than set for all conditions, P < .001. Set flow had a profound effect on measured CPAP. The concomitant drop in measured pressure with high and low flows could be attributed to increased resistance to spontaneous breathing or insufficient flow to meet inspiratory demand. Clinicians should be aware of the effect that the interface and flow have on CPAP delivery. Copyright © 2016 by Daedalus Enterprises.

Independent Verification and Validation of Complex User Interfaces: A Human Factors Approach

NASA Technical Reports Server (NTRS)

Whitmore, Mihriban; Berman, Andrea; Chmielewski, Cynthia

1996-01-01

The Usability Testing and Analysis Facility (UTAF) at the NASA Johnson Space Center has identified and evaluated a potential automated software interface inspection tool capable of assessing the degree to which space-related critical and high-risk software system user interfaces meet objective human factors standards across each NASA program and project. Testing consisted of two distinct phases. Phase 1 compared analysis times and similarity of results for the automated tool and for human-computer interface (HCI) experts. In Phase 2, HCI experts critiqued the prototype tool's user interface. Based on this evaluation, it appears that a more fully developed version of the tool will be a promising complement to a human factors-oriented independent verification and validation (IV&V) process.

Linear stability of an active fluid interface

NASA Astrophysics Data System (ADS)

Nagilla, Amarender; Prabhakar, Ranganathan; Jadhav, Sameer

2018-02-01

Motivated by studies suggesting that the patterns exhibited by the collectively expanding fronts of thin cells during the closing of a wound [S. Mark et al., "Physical model of the dynamic instability in an expanding cell culture," Biophys. J. 98(3), 361-370 (2010)] and the shapes of single cells crawling on surfaces [A. C. Callan-Jones et al., "Viscous-fingering-like instability of cell fragments," Phys. Rev. Lett. 100(25), 258106 (2008)] are due to fingering instabilities, we investigate the stability of actively driven interfaces under the Hele-Shaw confinement. An initially radial interface between a pair of viscous fluids is driven by active agents. Surface tension and bending rigidity resist the deformation of the interface. A point source at the origin and a distributed source are also included to model the effects of injection or suction and growth or depletion, respectively. Linear stability analysis reveals that for any given initial radius of the interface, there are two key dimensionless driving rates that determine interfacial stability. We discuss stability regimes in a state space of these parameters and their implications for biological systems. An interesting finding is that an actively mobile interface is susceptible to the fingering instability irrespective of viscosity contrast.

Development of Integrated Programs for Aerospace-vehicle design (IPAD): Reference design process

NASA Technical Reports Server (NTRS)

Meyer, D. D.

1979-01-01

The airplane design process and its interfaces with manufacturing and customer operations are documented to be used as criteria for the development of integrated programs for the analysis, design, and testing of aerospace vehicles. Topics cover: design process management, general purpose support requirements, design networks, and technical program elements. Design activity sequences are given for both supersonic and subsonic commercial transports, naval hydrofoils, and military aircraft.

10 CFR Appendix A1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Electric Refrigerators and Electric...

Code of Federal Regulations, 2012 CFR

2012-01-01

... less for the freezing and storage of ice. 1.3“Anti-sweat heater” means a device incorporated into the... interior surfaces of the cabinet. 1.4“Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat heaters. 1.5“Automatic defrost” means a...

10 CFR Appendix A to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Electric Refrigerators and Electric...

Code of Federal Regulations, 2012 CFR

2012-01-01

... capacity (14.2 liters) or less for the freezing and storage of ice. 1.3“Anti-sweat heater” means a device... on the exterior or interior surfaces of the cabinet. 1.4“Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat heaters. 1.5...

10 CFR Appendix B1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Freezers

Code of Federal Regulations, 2014 CFR

2014-01-01

... defined in HRF-1-1979 in cubic feet, times (2) an adjustment factor. 1.2 “Anti-sweat heater” means a... interior surfaces of the cabinet. 1.3 “Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat heaters. 1.4 “Automatic Defrost” means a...

10 CFR Appendix A to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Electric Refrigerators and Electric...

Code of Federal Regulations, 2014 CFR

2014-01-01

... capacity (14.2 liters) or less for the freezing and storage of ice. 1.3 “Anti-sweat heater” means a device... on the exterior or interior surfaces of the cabinet. 1.4 “Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat heaters. 1.5...

10 CFR Appendix B1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Freezers

Code of Federal Regulations, 2012 CFR

2012-01-01

... defined in HRF-1-1979 in cubic feet, times (2) an adjustment factor. 1.2“Anti-sweat heater” means a device... surfaces of the cabinet. 1.3“Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat heaters. 1.4“Automatic Defrost” means a system in...

10 CFR Appendix B1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Freezers

Code of Federal Regulations, 2013 CFR

2013-01-01

... defined in HRF-1-1979 in cubic feet, times (2) an adjustment factor. 1.2“Anti-sweat heater” means a device... surfaces of the cabinet. 1.3“Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat heaters. 1.4“Automatic Defrost” means a system in...

10 CFR Appendix A1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Electric Refrigerators and Electric...

Code of Federal Regulations, 2014 CFR

2014-01-01

... less for the freezing and storage of ice. 1.3 “Anti-sweat heater” means a device incorporated into the... interior surfaces of the cabinet. 1.4 “Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat heaters. 1.5 “Automatic defrost” means a...

10 CFR Appendix A to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Electric Refrigerators and Electric...

Code of Federal Regulations, 2013 CFR

2013-01-01

... capacity (14.2 liters) or less for the freezing and storage of ice. 1.3“Anti-sweat heater” means a device... on the exterior or interior surfaces of the cabinet. 1.4“Anti-sweat heater switch” means a user-controllable switch or user interface which modifies the activation or control of anti-sweat heaters. 1.5...

Ecohydrological Interfaces as Dynamic Hotspots of Biogeochemical Cycling

NASA Astrophysics Data System (ADS)

Krause, Stefan; Lewandowski, Joerg; Hannah, David; McDonald, Karlie; Folegot, Silvia; Baranov, Victor

2016-04-01

Ecohydrological interfaces, represent the boundaries between water-dependent ecosystems that can alter substantially the fluxes of energy and matter. There is still a critical gap of understanding the organisational principles of the drivers and controls of spatially and temporally variable ecohydrological interface functions. This knowledge gap limits our capacity to efficiently quantify, predict and manage the services provided by complex ecosystems. Many ecohydrological interfaces are characterized by step changes in microbial metabolic activity, steep redox gradients and often even thermodynamic phase shifts, for instance at the interfaces between atmosphere and water or soil matrix and macro-pores interfaces. This paper integrates investigations from point scale laboratory microcosm experiments with reach and subcatchment scale tracer experiments and numerical modeling studies to elaborate similarities in the drivers and controls that constitute the enhanced biogeochemical activity of different types of ecohydrologica interfaces across a range of spatial and temporal scales. We therefore combine smart metabolic activity tracers to quantify the impact of bioturbating benthic fauna onto ecosystem respiration and oxygen consumption and investigate at larger scale, how microbial metabolic activity and carbon turnover at the water-sediment interface are controlled by sediment physical and chemical properties as well as water temperatures. Numerical modeling confirmed that experimentally identified hotspots of streambed biogeochemical cycling were controlled by patterns of physical properties such as hydraulic conductivities or bioavailability of organic matter, impacting on residence time distributions and hence reaction times. In contrast to previous research, our investigations thus confirmed that small-scale variability of physical and chemical interface properties had a major impact on biogeochemical processing at the investigated ecohydrological interfaces. Our results furthermore indicate that to fully understand spatial patterns and temporal dynamics of ecohydrological interface functioning, including hotspots and hot moments, detailed knowledge of the impacts of biological behavior on the physic-chemical ecosystem conditions, and vice-versa, is required.

Ecohydrological Interfaces as Dynamic Hotspots of Biogeochemical Cycling

NASA Astrophysics Data System (ADS)

Krause, S.

2015-12-01

Ecohydrological interfaces, represent the boundaries between water-dependent ecosystems that can alter substantially the fluxes of energy and matter. There is still a critical gap of understanding the organisational principles of the drivers and controls of spatially and temporally variable ecohydrological interface functions. This knowledge gap limits our capacity to efficiently quantify, predict and manage the services provided by complex ecosystems. Many ecohydrological interfaces are characterized by step changes in microbial metabolic activity, steep redox gradients and often even thermodynamic phase shifts, for instance at the interfaces between atmosphere and water or soil matrix and macro-pores interfaces. This paper integrates investigations from point scale microcosm experiments with reach and subcatchment scale tracer experiments and numerical modeling studies to elaborate similarities in the drivers and controls that constitute the enhanced biogeochemical activity of different types of ecohydrologica interfaces across a range of spatial and temporal scales. We therefore combine smart metabolic activity tracers to quantify the impact of bioturbating benthic fauna onto ecosystem respiration and oxygen consumption and investigate at larger scale, how microbial metabolic activity and carbon turnover at the water-sediment interface are controlled by sediment physical and chemical properties as well as water temperatures. Numerical modeling confirmed that experimentally identified hotspots of streambed biogeochemical cycling were controlled by patterns of physical properties such as hydraulic conductivities or bioavailability of organic matter, impacting on residence time distributions and hence reaction times. In contrast to previous research, our investigations thus confirmed that small-scale variability of physical and chemical interface properties had a major impact on biogeochemical processing at the investigated ecohydrological interfaces. Our results furthermore indicate that to fully understand spatial patterns and temporal dynamics of ecohydrological interface functioning, including hotspots and hot moments, detailed knowledge of the impacts of biological behavior on the physic-chemical ecosystem conditions, and vice-versa, is required.

Optical sensors for electrical elements of a medium voltage distribution network

NASA Astrophysics Data System (ADS)

De Maria, Letizia; Bartalesi, Daniele; Serragli, Paolo; Paladino, Domenico

2012-04-01

The aging of most of the components of the National transmission and distribution system can potentially influence the reliability of power supply in a Medium Voltage (MV) network. In order to prevent possible dangerous situations, selected diagnostic indicators on electrical parts exploiting reliable and potentially low-cost sensors are required. This paper presents results concerning two main research activities regarding the development and application of innovative optical sensors for the diagnostic of MV electrical components. The first concerns a multi-sensor prototype for the detection of pre-discharges in MV switchboards: it is the combination of three different types of sensors operating simultaneously to detect incipient failure and to reduce the occurrence of false alarms. The system is real-time controlled by an embedded computer through a LabView interface. The second activity refers to a diagnostic tool to provide significant real-time information about early aging of MV/Low Voltage (LV) transformers by means of its vibration fingerprint. A miniaturized Optical Micro-Electro-Mechanical System (MEMS) based unit has been assembled for vibration measurements, wireless connected to a remote computer and controlled via LabView interface. Preliminary comparative tests were carried out with standard piezoelectric accelerometers on a conventional MV/LV test transformer under open circuit and in short-circuited configuration.

Shielding gas effect to diffusion activities of magnesium and copper on aluminum clad

NASA Astrophysics Data System (ADS)

Manurung, Charles SP; Napitupulu, Richard AM

2017-09-01

Aluminum is the second most metal used in many application, because of its corrosion resistance. The Aluminum will be damaged in over time if it’s not maintained in good condition. That is important to give protection to the Aluminums surface. Cladding process is one of surface protection methodes, especially for metals. Aluminum clad copper (Al/Cu) or copper clad aluminum (Cu/Al) composite metals have been widely used for many years. These mature protection method and well tested clad metal systems are used industrially in a variety application. The inherent properties and behavior of both copper and aluminum combine to provide unique performance advantages. In this paper Aluminum 2024 series will be covered with Aluminum 1100 series by hot rolling process. Observations will focus on diffusion activities of Mg and Cu that not present on Aluminum 1100 series. The differences of clad material samples is the use of shielding gas during heating before hot rolling process. The metallurgical characteristics will be examined by using optical microscopy. Transition zone from the interface cannot be observed but from Energy Dispersive Spectrometry it’s found that Mg and Cu are diffused from base metal (Al 2024) to the clad metal (Al 1100). Hardness test proved that base metals hardness to interface was decrease.

An experimental test of the fluctuation relation in an active camphor boat system

NASA Astrophysics Data System (ADS)

Paroor, H. M.; Nambiar, N.; Bandi, M. M.

The Gallavotti-Cohen fluctuation relation (FR) posits a specific symmetry between positive and negative fluctuations in entropy production, or a related quantity (e.g power) for systems in non-equilibrium stationary state. Successful tests in a variety of systems suggest the FR may be more generally applicable than the conditions under which it was originally derived. Systems where the FR fails are therefore valuable for the insight they provide into the FR's general success. It has recently been suggested that ``active matter'' should not satisfy the fluctuation-dissipation theorem or FR. We experimentally test this possibility in a system of active camphor boats, self-propelled by surface tension gradients at air-water interfaces. The boats interact via short-range capillary attraction which competes with long-range surface tension mediated repulsion. Tuning interaction strength with number density, we test the FR through the statistics of power as one goes from a free non-interacting camphor boat, through a few weakly interacting boats to several, strongly interacting boats. We present preliminary results of our experiments and data analysis.

Ownership and Agency of an Independent Supernumerary Hand Induced by an Imitation Brain-Computer Interface.

PubMed

Bashford, Luke; Mehring, Carsten

2016-01-01

To study body ownership and control, illusions that elicit these feelings in non-body objects are widely used. Classically introduced with the Rubber Hand Illusion, these illusions have been replicated more recently in virtual reality and by using brain-computer interfaces. Traditionally these illusions investigate the replacement of a body part by an artificial counterpart, however as brain-computer interface research develops it offers us the possibility to explore the case where non-body objects are controlled in addition to movements of our own limbs. Therefore we propose a new illusion designed to test the feeling of ownership and control of an independent supernumerary hand. Subjects are under the impression they control a virtual reality hand via a brain-computer interface, but in reality there is no causal connection between brain activity and virtual hand movement but correct movements are observed with 80% probability. These imitation brain-computer interface trials are interspersed with movements in both the subjects' real hands, which are in view throughout the experiment. We show that subjects develop strong feelings of ownership and control over the third hand, despite only receiving visual feedback with no causal link to the actual brain signals. Our illusion is crucially different from previously reported studies as we demonstrate independent ownership and control of the third hand without loss of ownership in the real hands.

Seal Investigations of an Active Clearance Control System Concept

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M.; Taylor, Shawn; Oswald, Jay; DeCastro, Jonathan A.

2006-01-01

In an effort to improve upon current thermal active clearance control methods, a first generation, fast-acting mechanically actuated, active clearance control system has been designed and installed into a non-rotating test rig. In order to harvest the benefit of tighter blade tip clearances, low-leakage seals are required for the actuated carrier segments of the seal shroud to prevent excessive leakage of compressor discharge (P3) cooling air. The test rig was designed and fabricated to facilitate the evaluation of these types of seals, identify seal leakage sources, and test other active clearance control system concepts. The objective of this paper is to present both experimental and analytical investigations into the nature of the face-seal to seal-carrier interface. Finite element analyses were used to examine face seal contact pressures and edge-loading under multiple loading conditions, varied E-seal positions and two new face seal heights. The analyses indicated that moving the E-seal inward radially and reducing face seal height would lead to more uniform contact conditions between the face seal and the carriers. Lab testing confirmed that moving the balance diameter inward radially caused a decrease in overall system leakage.

Supporting Real-Time Operations and Execution through Timeline and Scheduling Aids

NASA Technical Reports Server (NTRS)

Marquez, Jessica J.; Pyrzak, Guy; Hashemi, Sam; Ahmed, Samia; McMillin, Kevin Edward; Medwid, Joseph Daniel; Chen, Diana; Hurtle, Esten

2013-01-01

Since 2003, the NASA Ames Research Center has been actively involved in researching and advancing the state-of-the-art of planning and scheduling tools for NASA mission operations. Our planning toolkit SPIFe (Scheduling and Planning Interface for Exploration) has supported a variety of missions and field tests, scheduling activities for Mars rovers as well as crew on-board International Space Station and NASA earth analogs. The scheduled plan is the integration of all the activities for the day/s. In turn, the agents (rovers, landers, spaceships, crew) execute from this schedule while the mission support team members (e.g., flight controllers) follow the schedule during execution. Over the last couple of years, our team has begun to research and validate methods that will better support users during realtime operations and execution of scheduled activities. Our team utilizes human-computer interaction principles to research user needs, identify workflow processes, prototype software aids, and user test these. This paper discusses three specific prototypes developed and user tested to support real-time operations: Score Mobile, Playbook, and Mobile Assistant for Task Execution (MATE).

Fracture mechanics analysis for various fiber/matrix interface loadings

NASA Technical Reports Server (NTRS)

Naik, R. A.; Crews, J. H., Jr.

1991-01-01

Fiber/matrix (F/M) cracking was analyzed to provide better understanding and guidance in developing F/M interface fracture toughness tests. Two configurations, corresponding to F/M cracking at a broken fiber and at the free edge, were investigated. The effects of mechanical loading, thermal cooldown, and friction were investigated. Each configuration was analyzed for two loadings: longitudinal and normal to the fiber. A nonlinear finite element analysis was performed to model friction and slip at the F/M interface. A new procedure for fitting a square-root singularity to calculated stresses was developed to determine stress intensity factors (K sub I and K sub II) for a bimaterial interface crack. For the case of F/M cracking at a broken fiber with longitudinal loading, crack tip conditions were strongly influenced by interface friction. As a result, an F/M interface toughness test based on this case was not recommended because nonlinear data analysis methods would be required. For the free edge crack configuration, both mechanical and thermal loading caused crack opening, thereby avoiding frictional effects. A F/M interface toughness test based on this configuration would provide data for K(sub I)/K(sub II) ratios of about 0.7 and 1.6 for fiber and radial normal loading, respectively. However, thermal effects must be accounted for in the data analysis.

Fracture mechanics analysis for various fiber/matrix interface loadings

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.; Crews, John H., Jr.

1992-01-01

Fiber/matrix (F/M) cracking was analyzed to provide better understanding and guidance in developing F/M interface fracture toughness tests. Two configurations, corresponding to F/M cracking at a broken fiber and at the free edge, were investigated. The effects of mechanical loading, thermal cooldown, and friction were investigated. Each configuration was analyzed for two loadings: longitudinal and normal to the fiber. A nonlinear finite element analysis was performed to model friction and slip at the F/M interface. A new procedure for fitting a square-root singularity to calculated stresses was developed to determine stress intensity factors (K sub I and K sub II) for a bimaterial interface crack. For the case of F/M cracking at a broken fiber with longitudinal loading, crack tip conditions were strongly influenced by interface friction. As a result, an F/M interface toughness test based on this case was not recommended because nonlinear data analysis methods would be required. For the free edge crack configuration, both mechanical and thermal loading caused crack opening, theory avoiding fractional effects. A F/M interface toughness test based on this configuration would provide data for K(sub I/K(sub II) ratios of about 0.7 and 1.6 for fiber and radial normal loading, respectively. However, thermal effects must be accounted for in the data analysis.

Fracture mechanics analysis for various fiber/matrix interface loadings

NASA Technical Reports Server (NTRS)

Naik, R. A.; Crews, J. H., Jr.

1991-01-01

Fiber/matrix (F/M) cracking was analyzed to provide better understanding and guidance in developing F/M interface fracture toughness tests. Two configurations, corresponding to F/M cracking at a broken fiber and at the free edge, were investigated. The effects of mechanical loading, thermal cooldown, and friction were investigated. Each configuration was analyzed for two loadings: longitudinal and normal to the fiber. A nonlinear finite element analysis was performed to model friction and slip at the F/M interface. A new procedure for fitting a square-root singularity to calculated stresses was developed to determine stress intensity factors (K sub I and K sub II) for a bimaterial interface crack. For the case of F/M cracking at a broken fiber with longitudinal loading, crack tip conditions were strongly influenced by interface friction. As a result, an F/M interface toughness test based on this case was not recommended because nonlinear data analysis methods would be required. For the free edge crack configuration, both mechanical and thermal loading caused crack opening, thereby avoiding frictional effects. An F/M interface toughness test based on this configuration would provide data for K(sub I)/K(sub II) ratios of about 0.7 and 1.6 for fiber and radial normal loading, respectively. However, thermal effects must be accounted for in the data analysis.

Microstructural Characterization of the U-9.1Mo Fuel/AA6061 Cladding Interface in Friction-Bonded Monolithic Fuel Plates Irradiated in the RERTR-6 Experiment

DOE PAGES

Keiser, Dennis D.; Jue, Jan-Fong; Miller, Brandon; ...

2015-09-03

Low-enrichment (U-235 < 20%) U-Mo monolithic fuel is being developed for use in research and test reactors. The earliest design for this fuel that was investigated via reactor testing was comprised of a nominally U-10Mo fuel foil encased in AA6061 (Al-6061) cladding. For a fuel design to be deemed adequate for final use in a reactor, it must maintain dimensional stability and retain fission products throughout irradiation, which means that there must be good integrity at the fuel foil/cladding interface. To investigate the nature of the fuel/cladding interface for this fuel type after irradiation, fuel plates that were tested inmore » INL's Advanced Test Reactor (ATR) were subsequently characterized using optical metallography, scanning electron microscopy, and transmission electron microscopy. Results of this characterization showed that the fuel/cladding interaction layers present at the U-Mo fuel/AA6061 cladding interface after fabrication became amorphous during irradiation. Up to two main interaction layers, based on composition, could be found at the fuel/cladding interface, depending on location. After irradiation, an Al-rich layer contained very few fission gas bubbles, but did exhibit Xe enrichment near the AA6061 cladding interface. Another layer, which contained more Si, had more observable fission gas bubbles. Adjacent to the AA6061 cladding were Mg-rich precipitates, which was in close proximity to the region where Xe is observed to be enriched. In samples produced using a focused ion beam at the interaction zone/AA6061 cladding interface were possible indications of porosity/debonding, which suggested that the interface in this location is relatively weak.« less

Active oil-water interfaces: buckling and deformation of oil drops by bacteria

NASA Astrophysics Data System (ADS)

Juarez, Gabriel; Stocker, Roman

2014-11-01

Bacteria are unicellular organisms that seek nutrients and energy for growth, division, and self-propulsion. Bacteria are also natural colloidal particles that attach and self-assemble at liquid-liquid interfaces. Here, we present experimental results on active oil-water interfaces that spontaneously form when bacteria accumulate or grow on the interface. Using phase-contrast and fluorescence microscopy, we simultaneously observed the dynamics of adsorbed Alcanivorax bacteria and the oil-water interface within microfluidic devices. We find that, by growing and dividing, adsorbed bacteria form a jammed monolayer of cells that encapsulates the entire oil drop. As bacteria continue to grow at the interface, the drop buckles and the interface undergoes strong deformations. The bacteria act to stabilize non-equilibrium shapes of the oil-phase such wrinkling and tubulation. In addition to presenting a natural example of a living interface, these findings shape our understanding of microbial degradation of oil and may have important repercussions on engineering interventions for oil bioremediation.

Water at Biological Phase Boundaries: Its Role in Interfacial Activation of Enzymes and Metabolic Pathways.

PubMed

Damodaran, Srinivasan

2015-01-01

Many life-sustaining activities in living cells occur at the membrane-water interface. The pertinent questions that we need to ask are, what are the evolutionary reasons in biology for choosing the membrane-water interface as the site for performing and/or controlling crucial biological reactions, and what is the key physical principle that is very singular to the membrane-water interface that biology exploits for regulating metabolic processes in cells? In this chapter, a hypothesis is developed, which espouses that cells control activities of membrane-bound enzymes through manipulation of the thermodynamic activity of water in the lipid-water interfacial region. The hypothesis is based on the fact that the surface pressure of a lipid monolayer is a direct measure of the thermodynamic activity of water at the lipid-water interface. Accordingly, the surface pressure-dependent activation or inactivation of interfacial enzymes is directly related to changes in the thermodynamic activity of interfacial water. Extension of this argument suggests that cells may manipulate conformations (and activities) of membrane-bound enzymes by manipulating the (re)activity of interfacial water at various locations in the membrane by localized compression or expansion of the interface. In this respect, cells may use the membrane-bound hormone receptors, lipid phase transition, and local variations in membrane lipid composition as effectors of local compression and/or expansion of membrane, and thereby local water activity. Several experimental data in the literature will be reexamined in the light of this hypothesis.

Electrochemical impedance spectroscopy for quantitative interface state characterization of planar and nanostructured semiconductor-dielectric interfaces

NASA Astrophysics Data System (ADS)

Meng, Andrew C.; Tang, Kechao; Braun, Michael R.; Zhang, Liangliang; McIntyre, Paul C.

2017-10-01

The performance of nanostructured semiconductors is frequently limited by interface defects that trap electronic carriers. In particular, high aspect ratio geometries dramatically increase the difficulty of using typical solid-state electrical measurements (multifrequency capacitance- and conductance-voltage testing) to quantify interface trap densities (D it). We report on electrochemical impedance spectroscopy (EIS) to characterize the energy distribution of interface traps at metal oxide/semiconductor interfaces. This method takes advantage of liquid electrolytes, which provide conformal electrical contacts. Planar Al2O3/p-Si and Al2O3/p-Si0.55Ge0.45 interfaces are used to benchmark the EIS data against results obtained from standard electrical testing methods. We find that the solid state and EIS data agree very well, leading to the extraction of consistent D it energy distributions. Measurements carried out on pyramid-nanostructured p-Si obtained by KOH etching followed by deposition of a 10 nm ALD-Al2O3 demonstrate the application of EIS to trap characterization of a nanostructured dielectric/semiconductor interface. These results show the promise of this methodology to measure interface state densities for a broad range of semiconductor nanostructures such as nanowires, nanofins, and porous structures.

Expansion tube test time predictions

NASA Technical Reports Server (NTRS)

Gourlay, Christopher M.

1988-01-01

The interaction of an interface between two gases and strong expansion is investigated and the effect on flow in an expansion tube is examined. Two mechanisms for the unsteady Pitot-pressure fluctuations found in the test section of an expansion tube are proposed. The first mechanism depends on the Rayleigh-Taylor instability of the driver-test gas interface in the presence of a strong expansion. The second mechanism depends on the reflection of the strong expansion from the interface. Predictions compare favorably with experimental results. The theory is expected to be independent of the absolute values of the initial expansion tube filling pressures.

Competitive Adsorption between Nanoparticles and Surface Active Ions for the Oil-Water Interface.

PubMed

Hua, Xiaoqing; Bevan, Michael A; Frechette, Joelle

2018-04-24

Nanoparticles (NPs) can add functionality (e.g., catalytic, optical, rheological) to an oil-water interface. Adsorption of ∼10 nm NPs can be reversible; however, the mechanisms for adsorption and its effects on surface pressure remain poorly understood. Here we demonstrate how the competitive reversible adsorption of NPs and surfactants at fluid interfaces can lead to independent control of both the adsorbed amount and surface pressure. In contrast to prior work, both species investigated (NPs and surfactants) interact reversibly with the interface and without the surface active species binding to NPs. Independent measurements of the adsorption and surface pressure isotherms allow determination of the equation of state (EOS) of the interface under conditions where the NPs and surfactants are both in dynamic equilibrium with the bulk phase. The adsorption and surface pressure measurements are performed with gold NPs of two different sizes (5 and 10 nm), at two pH values, and across a wide concentration range of surfactant (tetrapentylammonium, TPeA + ) and NPs. We show that free surface active ions compete with NPs for the interface and give rise to larger surface pressures upon the adsorption of NPs. Through a competitive adsorption model, we decouple the contributions of NPs wetting at the interface and their surface activity on the measured surface pressure. We also demonstrate reversible control of adsorbed amount via changes in the surfactant concentration or the aqueous phase pH.

An Analytical Calculation of Frictional and Bending Moments at the Head-Neck Interface of Hip Joint Implants during Different Physiological Activities.

PubMed

Farhoudi, Hamidreza; Oskouei, Reza H; Pasha Zanoosi, Ali A; Jones, Claire F; Taylor, Mark

2016-12-05

This study predicts the frictional moments at the head-cup interface and frictional torques and bending moments acting on the head-neck interface of a modular total hip replacement across a range of activities of daily living. The predicted moment and torque profiles are based on the kinematics of four patients and the implant characteristics of a metal-on-metal implant. Depending on the body weight and type of activity, the moments and torques had significant variations in both magnitude and direction over the activity cycles. For the nine investigated activities, the maximum magnitude of the frictional moment ranged from 2.6 to 7.1 Nm. The maximum magnitude of the torque acting on the head-neck interface ranged from 2.3 to 5.7 Nm. The bending moment acting on the head-neck interface varied from 7 to 21.6 Nm. One-leg-standing had the widest range of frictional torque on the head-neck interface (11 Nm) while normal walking had the smallest range (6.1 Nm). The widest range, together with the maximum magnitude of torque, bending moment, and frictional moment, occurred during one-leg-standing of the lightest patient. Most of the simulated activities resulted in frictional torques that were near the previously reported oxide layer depassivation threshold torque. The predicted bending moments were also found at a level believed to contribute to the oxide layer depassivation. The calculated magnitudes and directions of the moments, applied directly to the head-neck taper junction, provide realistic mechanical loading data for in vitro and computational studies on the mechanical behaviour and multi-axial fretting at the head-neck interface.

An Analytical Calculation of Frictional and Bending Moments at the Head-Neck Interface of Hip Joint Implants during Different Physiological Activities

PubMed Central

Farhoudi, Hamidreza; Oskouei, Reza H.; Pasha Zanoosi, Ali A.; Jones, Claire F.; Taylor, Mark

2016-01-01

This study predicts the frictional moments at the head-cup interface and frictional torques and bending moments acting on the head-neck interface of a modular total hip replacement across a range of activities of daily living. The predicted moment and torque profiles are based on the kinematics of four patients and the implant characteristics of a metal-on-metal implant. Depending on the body weight and type of activity, the moments and torques had significant variations in both magnitude and direction over the activity cycles. For the nine investigated activities, the maximum magnitude of the frictional moment ranged from 2.6 to 7.1 Nm. The maximum magnitude of the torque acting on the head-neck interface ranged from 2.3 to 5.7 Nm. The bending moment acting on the head-neck interface varied from 7 to 21.6 Nm. One-leg-standing had the widest range of frictional torque on the head-neck interface (11 Nm) while normal walking had the smallest range (6.1 Nm). The widest range, together with the maximum magnitude of torque, bending moment, and frictional moment, occurred during one-leg-standing of the lightest patient. Most of the simulated activities resulted in frictional torques that were near the previously reported oxide layer depassivation threshold torque. The predicted bending moments were also found at a level believed to contribute to the oxide layer depassivation. The calculated magnitudes and directions of the moments, applied directly to the head-neck taper junction, provide realistic mechanical loading data for in vitro and computational studies on the mechanical behaviour and multi-axial fretting at the head-neck interface. PMID:28774104

Classification of mouth movements using 7 T fMRI.

PubMed

Bleichner, M G; Jansma, J M; Salari, E; Freudenburg, Z V; Raemaekers, M; Ramsey, N F

2015-12-01

A brain-computer interface (BCI) is an interface that uses signals from the brain to control a computer. BCIs will likely become important tools for severely paralyzed patients to restore interaction with the environment. The sensorimotor cortex is a promising target brain region for a BCI due to the detailed topography and minimal functional interference with other important brain processes. Previous studies have shown that attempted movements in paralyzed people generate neural activity that strongly resembles actual movements. Hence decodability for BCI applications can be studied in able-bodied volunteers with actual movements. In this study we tested whether mouth movements provide adequate signals in the sensorimotor cortex for a BCI. The study was executed using fMRI at 7 T to ensure relevance for BCI with cortical electrodes, as 7 T measurements have been shown to correlate well with electrocortical measurements. Twelve healthy volunteers executed four mouth movements (lip protrusion, tongue movement, teeth clenching, and the production of a larynx activating sound) while in the scanner. Subjects performed a training and a test run. Single trials were classified based on the Pearson correlation values between the activation patterns per trial type in the training run and single trials in the test run in a 'winner-takes-all' design. Single trial mouth movements could be classified with 90% accuracy. The classification was based on an area with a volume of about 0.5 cc, located on the sensorimotor cortex. If voxels were limited to the surface, which is accessible for electrode grids, classification accuracy was still very high (82%). Voxels located on the precentral cortex performed better (87%) than the postcentral cortex (72%). The high reliability of decoding mouth movements suggests that attempted mouth movements are a promising candidate for BCI in paralyzed people.

Mechanical and histological analysis of bone-pedicle screw interface in vivo: titanium versus stainless steel.

PubMed

Sun, C; Huang, G; Christensen, F B; Dalstra, M; Overgaard, S; Bünger, C

1999-05-01

To investigate the differences in bone interface between titanium and stainless steel pedicle screws in the lumbar spine. Eighteen adult mini-pigs that underwent total laminectomy, posterolateral spinal fusion (L4-L5) were randomly selected to receive stainless steel (9) or titanium pedicle screw devices (9). In both groups, the devices were CCD (Sofamore Danek) type with the same size and shape. The postoperative observation time was 3 months. Screws from L4 were harvested along their long axis of pedicle for histomorphometric study. Bone-screw interface and bone volume from thread were examined using linear intercept techniques. Mechanical testing (torsional test and pull-out test) was performed on the screws from L5. The titanium screw group had a significantly higher maximum torque (P < 0.05) and angle related stiffness (P < 0.05) measured by torsional test. In the pull-out tests, no differences were found between the two groups in relation to the maximum load, stiffness and energy to failure. Direct bone contact with the screw in percentage was 29.4% for stainless steel and 43.8% for titanium (P < 0.05). No differences in the bone purchase between the vertebral body part and pedicle part were found. Pedicle screws made of titanium have a better bone-screw interface binding than screws made of stainless steel. Torsional tests are more informative for bone-screw interface study. Pull-out tests seem less valuable when comparing bone purchase of screws made from different materials.

Quantifying hyporheic exchange in a karst stream using 222Rn

NASA Astrophysics Data System (ADS)

Khadka, M. B.; Martin, J. B.; Kurz, M. J.

2013-12-01

The hyporheic zone is a critical interface between groundwater and river water environments and is characterized by steep biogeochemical gradients. Understanding how this interface affects solute transport, nutrient cycling and contaminant attenuation is essential for better water resource management of streams. However, this understanding is constrained due to difficulty associated with quantification of exchange of water through the hyporheic zone. We tested a radon (222Rn) method to estimate the hyporheic water residence time and exchange rate in the bottom sediment of the spring-fed Ichetucknee River, north-central Florida. The river, which flows over the top of the unconfined karstic Floridan Aquifer, is characterized by a broad bedrock channel partially in-filled with unconsolidated sediments. Radon (222Rn) activity in the pore waters of the channel sediments differs from the amount expected from sediment production and decay. Although most radon in streams originates from sources in bottom sediments, the Ichetucknee River water has 222Rn activities (251×5 PCi/L) that are nearly twice that of the pore water (128×15 PCi/L). The river water 222Rn activity is consistent with that of the source springs, suggesting the source of Rn in the river is from deep within the aquifer rather than bottom sediments and that the excess 222Rn in the pore water results from hyporheic exchange. Profiles of radon concentrations with depth through the sediments show that the mixing of stream water and pore water extends 35-45 cm below the sediment and water interface. Based on a model that integrates the excess radon with depth, we estimate the water exchange rate to be between 1.1 and 1.6 cm/day with an average value of 1.3×0.2 cm/day. Water that exchanges across the sediment-water interface pumps oxygen into the sediments, thereby enhancing organic carbon remineralization, as well as the production of NH4+ and PO43- and their fluxes from sediments to the stream. As opposed to conventional in-stream tracer injection method which estimates exchange between the stream and both the hyporheic zone and the surface transient storage zone, the 222Rn approach measures the water exchange between stream and hyporheic sediments only. Although the present method is tested on a spring-fed karst stream, it has potential for any freshwater system (e.g. wetland, lake) where distinct radon activity and production between surface water and underlying sediments occur.

Changes in functional brain organization and behavioral correlations after rehabilitative therapy using a brain-computer interface.

PubMed

Young, Brittany M; Nigogosyan, Zack; Walton, Léo M; Song, Jie; Nair, Veena A; Grogan, Scott W; Tyler, Mitchell E; Edwards, Dorothy F; Caldera, Kristin; Sattin, Justin A; Williams, Justin C; Prabhakaran, Vivek

2014-01-01

This study aims to examine the changes in task-related brain activity induced by rehabilitative therapy using brain-computer interface (BCI) technologies and whether these changes are relevant to functional gains achieved through the use of these therapies. Stroke patients with persistent upper-extremity motor deficits received interventional rehabilitation therapy using a closed-loop neurofeedback BCI device (n = 8) or no therapy (n = 6). Behavioral assessments using the Stroke Impact Scale, the Action Research Arm Test (ARAT), and the Nine-Hole Peg Test (9-HPT) as well as task-based fMRI scans were conducted before, during, after, and 1 month after therapy administration or at analogous intervals in the absence of therapy. Laterality Index (LI) values during finger tapping of each hand were calculated for each time point and assessed for correlation with behavioral outcomes. Brain activity during finger tapping of each hand shifted over the course of BCI therapy, but not in the absence of therapy, to greater involvement of the non-lesioned hemisphere (and lesser involvement of the stroke-lesioned hemisphere) as measured by LI. Moreover, changes from baseline LI values during finger tapping of the impaired hand were correlated with gains in both objective and subjective behavioral measures. These findings suggest that the administration of interventional BCI therapy can induce differential changes in brain activity patterns between the lesioned and non-lesioned hemispheres and that these brain changes are associated with changes in specific motor functions.

Circling motion and screen edges as an alternative input method for on-screen target manipulation.

PubMed

Ka, Hyun W; Simpson, Richard C

2017-04-01

To investigate a new alternative interaction method, called circling interface, for manipulating on-screen objects. To specify a target, the user makes a circling motion around the target. To specify a desired pointing command with the circling interface, each edge of the screen is used. The user selects a command before circling the target. To evaluate the circling interface, we conducted an experiment with 16 participants, comparing the performance on pointing tasks with different combinations of selection method (circling interface, physical mouse and dwelling interface) and input device (normal computer mouse, head pointer and joystick mouse emulator). A circling interface is compatible with many types of pointing devices, not requiring physical activation of mouse buttons, and is more efficient than dwell-clicking. Across all common pointing operations, the circling interface had a tendency to produce faster performance with a head-mounted mouse emulator than with a joystick mouse. The performance accuracy of the circling interface outperformed the dwelling interface. It was demonstrated that the circling interface has the potential as another alternative pointing method for selecting and manipulating objects in a graphical user interface. Implications for Rehabilitation A circling interface will improve clinical practice by providing an alternative pointing method that does not require physically activating mouse buttons and is more efficient than dwell-clicking. The Circling interface can also work with AAC devices.

Usability Testing and Analysis Facility (UTAF)

NASA Technical Reports Server (NTRS)

Wong, Douglas T.

2010-01-01

This slide presentation reviews the work of the Usability Testing and Analysis Facility (UTAF) at NASA Johnson Space Center. It is one of the Space Human Factors Laboratories in the Habitability and Human Factors Branch (SF3) at NASA Johnson Space Center The primary focus pf the UTAF is to perform Human factors evaluation and usability testing of crew / vehicle interfaces. The presentation reviews the UTAF expertise and capabilities, the processes and methodologies, and the equipment available. It also reviews the programs that it has supported detailing the human engineering activities in support of the design of the Orion space craft, testing of the EVA integrated spacesuit, and work done for the design of the lunar projects of the Constellation Program: Altair, Lunar Electric Rover, and Outposts

On-line analysis capabilities developed to support the AFW wind-tunnel tests

NASA Technical Reports Server (NTRS)

Wieseman, Carol D.; Hoadley, Sherwood T.; Mcgraw, Sandra M.

1992-01-01

A variety of on-line analysis tools were developed to support two active flexible wing (AFW) wind-tunnel tests. These tools were developed to verify control law execution, to satisfy analysis requirements of the control law designers, to provide measures of system stability in a real-time environment, and to provide project managers with a quantitative measure of controller performance. Descriptions and purposes of the developed capabilities are presented along with examples. Procedures for saving and transferring data for near real-time analysis, and descriptions of the corresponding data interface programs are also presented. The on-line analysis tools worked well before, during, and after the wind tunnel test and proved to be a vital and important part of the entire test effort.

Ant-Based Cyber Defense (also known as

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glenn Fink, PNNL

2015-09-29

ABCD is a four-level hierarchy with human supervisors at the top, a top-level agent called a Sergeant controlling each enclave, Sentinel agents located at each monitored host, and mobile Sensor agents that swarm through the enclaves to detect cyber malice and misconfigurations. The code comprises four parts: (1) the core agent framework, (2) the user interface and visualization, (3) test-range software to create a network of virtual machines including a simulated Internet and user and host activity emulation scripts, and (4) a test harness to allow the safe running of adversarial code within the framework of monitored virtual machines.

Using a Modular Open Systems Approach in Defense Acquisitions: Implications for the Contracting Process

DTIC Science & Technology

2006-01-30

He has taught contract management courses for the UCLA Government Contracts Certificate program and is also a senior faculty member for the Keller...standards for its key interfaces, and has been subjected to successful validation and verification tests to ensure the openness of its key interfaces...widely supported and consensus based standards for its key interfaces, and is subject to validation and verification tests to ensure the openness of its

Integrated Information Support System (IISS). Volume 8. User Interface Subsystem. Part 3. User Interface Services Product Specification.

DTIC Science & Technology

1985-11-01

User Interface that consists of a set of callable execution time routines available to an application program for form processing . IISS Function Screen...provisions for test consists of the normal testing techniques that are accomplished during the construction process . They consist of design and code...application presents a form * to the user which must be filled in with information for processing by that application. The application then

Acoustic emission as a screening tool for ceramic matrix composites

NASA Astrophysics Data System (ADS)

Ojard, Greg; Goberman, Dan; Holowczak, John

2017-02-01

Ceramic matrix composites are composite materials with ceramic fibers in a high temperature matrix of ceramic or glass-ceramic. This emerging class of materials is viewed as enabling for efficiency improvements in many energy conversion systems. The key controlling property of ceramic matrix composites is a relatively weak interface between the matrix and the fiber that aids crack deflection and fiber pullout resulting in greatly increased toughness over monolithic ceramics. United Technologies Research Center has been investigating glass-ceramic composite systems as a tool to understand processing effects on material performance related to the performance of the weak interface. Changes in the interface have been shown to affect the mechanical performance observed in flexural testing and subsequent microstructural investigations have confirmed the performance (or lack thereof) of the interface coating. Recently, the addition of acoustic emission testing during flexural testing has aided the understanding of the characteristics of the interface and its performance. The acoustic emission onset stress changes with strength and toughness and this could be a quality tool in screening the material before further development and use. The results of testing and analysis will be shown and additional material from other ceramic matrix composite systems may be included to show trends.

Interface bonding of shotcrete reinforced brick masonry assemblages, volume 1

NASA Astrophysics Data System (ADS)

Robinson, D. W.; Kahn, L. F.

1982-09-01

Nine 9 sq ft. shotcrete reinforced brick masonry assemblages and one 9 sq ft brick masonry control specimen were tested under a single reversed cycle diagonal compression load similar to the ASTM E519-74 testing procedures. The interface surface conditions, between the brick and shotcrete were varied. The surfaces of the single sythe of old brick were either dry, wet, or epoxy coated before application of the 3-inch reinforced shotcrete layer. Ultimate load capacities of the specimens were similar, however, specimens with epoxy-enhanced interfaces were the most ductile; the dry brick specimens showed interface bond failure immediately after the ultimate inplane load was attained.

Transire, a Program for Generating Solid-State Interface Structures

DTIC Science & Technology

2017-09-14

function-based electron transport property calculator. Three test cases are presented to demonstrate the usage of Transire: the misorientation of the...graphene bilayer, the interface energy as a function of misorientation of copper grain boundaries, and electron transport transmission across the...gallium nitride/silicon carbide interface. 15. SUBJECT TERMS crystalline interface, electron transport, python, computational chemistry, grain boundary

The Benefits and Challenges of an Interfaced Electronic Health Record and Laboratory Information System: Effects on Laboratory Processes.

PubMed

Petrides, Athena K; Bixho, Ida; Goonan, Ellen M; Bates, David W; Shaykevich, Shimon; Lipsitz, Stuart R; Landman, Adam B; Tanasijevic, Milenko J; Melanson, Stacy E F

2017-03-01

- A recent government regulation incentivizes implementation of an electronic health record (EHR) with computerized order entry and structured results display. Many institutions have also chosen to interface their EHR with their laboratory information system (LIS). - To determine the impact of an interfaced EHR-LIS on laboratory processes. - We analyzed several different processes before and after implementation of an interfaced EHR-LIS: the turnaround time, the number of stat specimens received, venipunctures per patient per day, preanalytic errors in phlebotomy, the number of add-on tests using a new electronic process, and the number of wrong test codes ordered. Data were gathered through the LIS and/or EHR. - The turnaround time for potassium and hematocrit decreased significantly (P = .047 and P = .004, respectively). The number of stat orders also decreased significantly, from 40% to 7% for potassium and hematocrit, respectively (P < .001 for both). Even though the average number of inpatient venipunctures per day increased from 1.38 to 1.62 (P < .001), the average number of preanalytic errors per month decreased from 2.24 to 0.16 per 1000 specimens (P < .001). Overall there was a 16% increase in add-on tests. The number of wrong test codes ordered was high and it was challenging for providers to correctly order some common tests. - An interfaced EHR-LIS significantly improved within-laboratory turnaround time and decreased stat requests and preanalytic phlebotomy errors. Despite increasing the number of add-on requests, an electronic add-on process increased efficiency and improved provider satisfaction. Laboratories implementing an interfaced EHR-LIS should be cautious of its effects on test ordering and patient venipunctures per day.

75 FR 7283 - Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-18

... Interface Activities for Avian Influenza and Other Zoonotic Diseases, Funding Opportunity Announcement (FOA... Interface Activities for Avian Influenza and other Zoonotic Diseases, FOA CK10-001.'' Contact Person for...

Orbital operation study. Volume 2: Interfacing activities analysis. Part 1: Introduction and summary

NASA Technical Reports Server (NTRS)

Anderson, N. R.

1972-01-01

The summary of the interfacing activity analyses for the orbital operations study is presented. The significant analyses are grouped into categories as follows: (1) structural and mechanical activity, (2) data management, and (3) support operations. Specific subjects concerning payload deployment, communications, rendezvous, and stationkeeping are discussed.

Simulation of the «COSMONAUT-ROBOT» System Interaction on the Lunar Surface Based on Methods of Machine Vision and Computer Graphics

NASA Astrophysics Data System (ADS)

Kryuchkov, B. I.; Usov, V. M.; Chertopolokhov, V. A.; Ronzhin, A. L.; Karpov, A. A.

2017-05-01

Extravehicular activity (EVA) on the lunar surface, necessary for the future exploration of the Moon, involves extensive use of robots. One of the factors of safe EVA is a proper interaction between cosmonauts and robots in extreme environments. This requires a simple and natural man-machine interface, e.g. multimodal contactless interface based on recognition of gestures and cosmonaut's poses. When travelling in the "Follow Me" mode (master/slave), a robot uses onboard tools for tracking cosmonaut's position and movements, and on the basis of these data builds its itinerary. The interaction in the system "cosmonaut-robot" on the lunar surface is significantly different from that on the Earth surface. For example, a man, dressed in a space suit, has limited fine motor skills. In addition, EVA is quite tiring for the cosmonauts, and a tired human being less accurately performs movements and often makes mistakes. All this leads to new requirements for the convenient use of the man-machine interface designed for EVA. To improve the reliability and stability of human-robot communication it is necessary to provide options for duplicating commands at the task stages and gesture recognition. New tools and techniques for space missions must be examined at the first stage of works in laboratory conditions, and then in field tests (proof tests at the site of application). The article analyzes the methods of detection and tracking of movements and gesture recognition of the cosmonaut during EVA, which can be used for the design of human-machine interface. A scenario for testing these methods by constructing a virtual environment simulating EVA on the lunar surface is proposed. Simulation involves environment visualization and modeling of the use of the "vision" of the robot to track a moving cosmonaut dressed in a spacesuit.

Adhesion mechanisms of bituminous crack sealant to aggregate and laboratory test development

NASA Astrophysics Data System (ADS)

Hajialiakbari Fini, Elham

Crack sealing is a common pavement maintenance treatment because it extends pavement service life. However, crack sealant often fails prematurely due to a loss of adhesion. Since current test methods are mostly empirical and only provide a qualitative measure of bond strength, they cannot predict sealant adhesive failure accurately. Hence, there is an urgent need for test methods based on bituminous sealant rheology that can better predict sealant field performance. This study introduces three laboratory tests aimed to assess the bond property of hot-poured crack sealant to pavement crack walls. The three tests are designed to serve the respective needs of producers, engineers, and researchers. The first test implements the principle of surface energy to measure the thermodynamic work of adhesion, which is the energy spent in separating the two materials at the interface. The work of adhesion is reported as a measure of material compatibility at an interface. The second test is a direct adhesion test, a mechanical test which is designed to closely resemble both the installation process and the crack expansion due to thermal loading. This test uses the Direct Tension Test (DTT) device. The principle of the test is to apply a tensile force to detach the sealant from its aggregate counterpart. The maximum load, Pmax, and the energy to separation, E, are calculated and reported to indicate interface bonding. The third test implements the principles of fracture mechanics in a pressurized circular blister test. The apparatus is specifically designed to conduct the test for bituminous crack sealant, asphalt binder, or other bitumen-based materials. In this test, a fluid is injected at a constant rate at the interface between the substrate (aggregate or a standard material) and the adhesive (crack sealant) to create a blister. The fluid pressure and blister height are measured as functions of time; the data is used to calculate Interfacial Fracture Energy (IFE), which is a fundamental property that can be used to predict adhesion. The stable interface debonding process makes this test attractive. This test also may be used to estimate the optimum annealing time, and to quantify other interface characteristics, such as the moisture susceptibility of a bond. In addition, the elastic modulus of the sealant and its residual stresses can be determined analytically. While the direct adhesion test is proposed as part of newly-developed performance-based guidelines for the selection of hot-poured crack sealant, the blister test may be used to estimate the optimum annealing time, in addition to IFE determination.

Virtual screening using combinatorial cyclic peptide libraries reveals protein interfaces readily targetable by cyclic peptides.

PubMed

Duffy, Fergal J; O'Donovan, Darragh; Devocelle, Marc; Moran, Niamh; O'Connell, David J; Shields, Denis C

2015-03-23

Protein-protein and protein-peptide interactions are responsible for the vast majority of biological functions in vivo, but targeting these interactions with small molecules has historically been difficult. What is required are efficient combined computational and experimental screening methods to choose among a number of potential protein interfaces worthy of targeting lead macrocyclic compounds for further investigation. To achieve this, we have generated combinatorial 3D virtual libraries of short disulfide-bonded peptides and compared them to pharmacophore models of important protein-protein and protein-peptide structures, including short linear motifs (SLiMs), protein-binding peptides, and turn structures at protein-protein interfaces, built from 3D models available in the Protein Data Bank. We prepared a total of 372 reference pharmacophores, which were matched against 108,659 multiconformer cyclic peptides. After normalization to exclude nonspecific cyclic peptides, the top hits notably are enriched for mimetics of turn structures, including a turn at the interaction surface of human α thrombin, and also feature several protein-binding peptides. The top cyclic peptide hits also cover the critical "hot spot" interaction sites predicted from the interaction crystal structure. We have validated our method by testing cyclic peptides predicted to inhibit thrombin, a key protein in the blood coagulation pathway of important therapeutic interest, identifying a cyclic peptide inhibitor with lead-like activity. We conclude that protein interfaces most readily targetable by cyclic peptides and related macrocyclic drugs may be identified computationally among a set of candidate interfaces, accelerating the choice of interfaces against which lead compounds may be screened.

Mission Control Center (MCC) system specification for the shuttle Orbital Flight Test (OFT) timeframe

NASA Technical Reports Server (NTRS)

1978-01-01

The Mission Control Center Shuttle (MCC) Shuttle Orbital Flight Test (OFT) Data System (OFTDS) provides facilities for flight control and data systems personnel to monitor and control the Shuttle flights from launch (tower clear) to rollout (wheels stopped on runway). It also supports the preparation for flight (flight planning, flight controller and crew training, and integrated vehicle and network testing activities). The MCC Shuttle OFTDS is described in detail. Three major support systems of the OFTDS and the data types and sources of data entering or exiting the MCC were illustrated. These systems are the communication interface system, the data computation complex, and the display and control system.

KSC-00pp1608

NASA Image and Video Library

2000-10-23

STS-98 Mission Specialist Thomas Jones practices handling a piece of equipment on the U.S. Lab, Destiny, while wearing the gloves he will wear in space. Jones and other crew members are taking part in Crew Equipment Interface Test activities to become familiar with equipment they will be handling during the mission. With launch scheduled for Jan. 18, 2001, the STS-98 mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1768

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- STS-98 Mission Specialist Marsha Ivins takes a topsy-turvy look at the EVA hatch in the Orbiter Docking System, which is already installed in the payload bay of orbiter Atlantis. She and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC-00pp1768

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- STS-98 Mission Specialist Marsha Ivins takes a topsy-turvy look at the EVA hatch in the Orbiter Docking System, which is already installed in the payload bay of orbiter Atlantis. She and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC-07pd2606

NASA Image and Video Library

2007-09-28

KENNEDY SPACE CENTER, FLA. -- Astronaut Leopold Eyharts, who represents the European Space Agency, tries on a harness in the Orbiter Processing Facility. Eyharts will be traveling to the International Space Station to join the Expedition 16 crew as a flight engineer. The crew is at Kennedy to take part in a crew equipment interface test, or CEIT, which helps familiarize them with equipment and payloads for the mission. Among the activities standard to a CEIT are harness training, inspection of the thermal protection system and camera operation for planned extravehicular activities, or EVAs. STS-122 is targeted for launch in December. Photo credit: NASA/Kim Shiflett

KSC-07pd2605

NASA Image and Video Library

2007-09-28

KENNEDY SPACE CENTER, FLA. -- Members of the STS-122 crew take part in harness training in the Orbiter Processing Facility at NASA's Kennedy Space Center. Seen from left are Mission Specialists Stanley Love and Leland Melvin and Pilot Alan Poindexter. The crew is at Kennedy to take part in a crew equipment interface test, or CEIT, which helps familiarize them with equipment and payloads for the mission. Among the activities standard to a CEIT are harness training, inspection of the thermal protection system and camera operation for planned extravehicular activities, or EVAs. STS-122 is targeted for launch in December. Photo credit: NASA/Kim Shiflett

A programmable closed-loop recording and stimulating wireless system for behaving small laboratory animals

PubMed Central

Angotzi, Gian Nicola; Boi, Fabio; Zordan, Stefano; Bonfanti, Andrea; Vato, Alessandro

2014-01-01

A portable 16-channels microcontroller-based wireless system for a bi-directional interaction with the central nervous system is presented in this work. The device is designed to be used with freely behaving small laboratory animals and allows recording of spontaneous and evoked neural activity wirelessly transmitted and stored on a personal computer. Biphasic current stimuli with programmable duration, frequency and amplitude may be triggered in real-time on the basis of the recorded neural activity as well as by the animal behavior within a specifically designed experimental setup. An intuitive graphical user interface was developed to configure and to monitor the whole system. The system was successfully tested through bench tests and in vivo measurements on behaving rats chronically implanted with multi-channels microwire arrays. PMID:25096831

KSC-03PD-0187

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. -- During Crew Equipment Interface Test activities in the Space Station Processing Facility, STS-115 Mission Specialists Heidemarie Stefanyshyn-Piper and Joseph Tanner look at equipment. The mission will deliver the second port truss segment, the P3/P4 Truss, to attach to the first port truss segment, the P1 Truss, as well as deploy solar array set 2A and 4A. Launch on Space Shuttle Endeavour is scheduled for May 23, 2003.

An overview of the measurements of soil moisture and modeling of moisture flux in FIFE

NASA Technical Reports Server (NTRS)

Wang, J. R.

1992-01-01

Measurements of soil moisture and calculations of moisture transfer in the soil medium and at the air-soil interface were performed over a 15-km by 15-km test site during FIFE in 1987 and 1989. The measurements included intensive soil moisture sampling at the ground level and surveys at aircraft altitudes by several passive and active microwave sensors as well as a gamma radiation device.

Orbital operations study. Appendix A: Interactivity analysis

NASA Technical Reports Server (NTRS)

1972-01-01

Supplemental analyses conducted to verify that safe, feasible, design concepts exist for accomplishing the attendant interface activities of the orbital operations mission are presented. The data are primarily concerned with functions and concepts common to more than one of the interfacing activities or elements. Specific consideration is given to state vector update, payload deployment, communications links, jet plume impingement, attached element operations, docking and structural interface assessment, and propellant transfer.

Decoding bipedal locomotion from the rat sensorimotor cortex

NASA Astrophysics Data System (ADS)

Rigosa, J.; Panarese, A.; Dominici, N.; Friedli, L.; van den Brand, R.; Carpaneto, J.; DiGiovanna, J.; Courtine, G.; Micera, S.

2015-10-01

Objective. Decoding forelimb movements from the firing activity of cortical neurons has been interfaced with robotic and prosthetic systems to replace lost upper limb functions in humans. Despite the potential of this approach to improve locomotion and facilitate gait rehabilitation, decoding lower limb movement from the motor cortex has received comparatively little attention. Here, we performed experiments to identify the type and amount of information that can be decoded from neuronal ensemble activity in the hindlimb area of the rat motor cortex during bipedal locomotor tasks. Approach. Rats were trained to stand, step on a treadmill, walk overground and climb staircases in a bipedal posture. To impose this gait, the rats were secured in a robotic interface that provided support against the direction of gravity and in the mediolateral direction, but behaved transparently in the forward direction. After completion of training, rats were chronically implanted with a micro-wire array spanning the left hindlimb motor cortex to record single and multi-unit activity, and bipolar electrodes into 10 muscles of the right hindlimb to monitor electromyographic signals. Whole-body kinematics, muscle activity, and neural signals were simultaneously recorded during execution of the trained tasks over multiple days of testing. Hindlimb kinematics, muscle activity, gait phases, and locomotor tasks were decoded using offline classification algorithms. Main results. We found that the stance and swing phases of gait and the locomotor tasks were detected with accuracies as robust as 90% in all rats. Decoded hindlimb kinematics and muscle activity exhibited a larger variability across rats and tasks. Significance. Our study shows that the rodent motor cortex contains useful information for lower limb neuroprosthetic development. However, brain-machine interfaces estimating gait phases or locomotor behaviors, instead of continuous variables such as limb joint positions or speeds, are likely to provide more robust control strategies for the design of such neuroprostheses.

TRU waste lead organization -- WIPP Project Office Interface Management semi-annual report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guerrero, J.V.; Gorton, J.M.

1985-05-01

The Charter establishing the Interface Control Board and the administrative organization to manage the interface of the TRU Waste Lead Organization and the WIPP Project Office also requires preparation of a summary report describing significant interface activities.'' This report includes a discussion of Interface Working Group (IWG) recommendations and resolutions considered and implemented'' over the reporting period October 1984 to March 1985.

Improved efficacy of soluble human receptor activator of nuclear factor kappa B (RANK) fusion protein by site-directed mutagenesis.

PubMed

Son, Young Jun; Han, Jihye; Lee, Jae Yeon; Kim, HaHyung; Chun, Taehoon

2015-06-01

Soluble human receptor activator of nuclear factor kappa B fusion immunoglobulin (hRANK-Ig) has been considered as one of the therapeutic agents to treat osteoporosis or diseases associated with bone destruction by blocking the interaction between RANK and the receptor activator of nuclear factor kappa B ligand (RANKL). However, no scientific record showing critical amino acid residues within the structural interface between the human RANKL and RANK complex is yet available. In this study, we produced several mutants of hRANK-Ig by replacement of amino acid residue(s) and tested whether the mutants had increased binding affinity to human RANKL. Based on the results from flow cytometry and surface plasmon resonance analyses, the replacement of E(125) with D(125), or E(125) and C(127) with D(125) and F(127) within loop 3 of cysteine-rich domain 3 of hRANK-Ig increases binding affinity to human RANKL over the wild-type hRANK-Ig. This result may provide the first example of improvement in the efficacy of hRANK-Ig by protein engineering and may give additional information to understand a more defined structural interface between hRANK and RANKL.

A four-dimensional virtual hand brain-machine interface using active dimension selection.

PubMed

Rouse, Adam G

2016-06-01

Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. ADS utilizes a two stage decoder by using neural signals to both (i) select an active dimension being controlled and (ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits s(-1) for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand.

User-Friendly Interface Developed for a Web-Based Service for SpaceCAL Emulations

NASA Technical Reports Server (NTRS)

Liszka, Kathy J.; Holtz, Allen P.

2004-01-01

A team at the NASA Glenn Research Center is developing a Space Communications Architecture Laboratory (SpaceCAL) for protocol development activities for coordinated satellite missions. SpaceCAL will provide a multiuser, distributed system to emulate space-based Internet architectures, backbone networks, formation clusters, and constellations. As part of a new effort in 2003, building blocks are being defined for an open distributed system to make the satellite emulation test bed accessible through an Internet connection. The first step in creating a Web-based service to control the emulation remotely is providing a user-friendly interface for encoding the data into a well-formed and complete Extensible Markup Language (XML) document. XML provides coding that allows data to be transferred between dissimilar systems. Scenario specifications include control parameters, network routes, interface bandwidths, delay, and bit error rate. Specifications for all satellite, instruments, and ground stations in a given scenario are also included in the XML document. For the SpaceCAL emulation, the XML document can be created using XForms, a Webbased forms language for data collection. Contrary to older forms technology, the interactive user interface makes the science prevalent, not the data representation. Required versus optional input fields, default values, automatic calculations, data validation, and reuse will help researchers quickly and accurately define missions. XForms can apply any XML schema defined for the test mission to validate data before forwarding it to the emulation facility. New instrument definitions, facilities, and mission types can be added to the existing schema. The first prototype user interface incorporates components for interactive input and form processing. Internet address, data rate, and the location of the facility are implemented with basic form controls with default values provided for convenience and efficiency using basic XForms operations. Because different emulation scenarios will vary widely in their component structure, more complex operations are used to add and delete facilities.

Effects of Model Salivary Esterases and MMP Inhibition on the Restoration's Marginal Integrity and Potential Degradative Contribution of Cariogenic Bacteria

NASA Astrophysics Data System (ADS)

Huang, Bo

Enzyme-catalyzed degradation of the restoration-tooth interface compromises interfacial integrity, thereby contributing to secondary caries, which is a major cause of resin-based restoration failure. It is hypothesized that in addition to salivary esterases, the cariogenic bacterium Streptococcus mutans has specific esterases that degrade the resin-dentin interface, releasing biodegradation by- products (BBPs) such as bis-hydroxy-propoxy-phenyl-propane (BisHPPP). In turn, BisHPPP affects S. mutans by stimulating the expression of esterases. Another hypothesis is that the biostability of the resin-dentin interface is affected by simulated salivary esterases, dentinal matrix metalloproteinase (MMP) inhibition, and restorative materials. To test the first hypothesis, putative esterase genes in S. mutans UA159 were identified, purified, and characterized. SMU_118c was identified as the dominant esterase in S. mutans UA159 and showed a similar hydrolytic activity profile to salivary esterases. BisHPPP upregulated expression of the SMU_118c gene and related protein in a concentration-dependent manner. This positive feedback process could accelerate the degradation of the restoration-tooth interface and lead to premature restoration failure. To test the second hypothesis, an in vitro model was established to evaluate the effects of salivary esterases, MMP inhibition and restorative materials on interfacial integrity. It was confirmed that interfacial integrity was compromised with time and was further deteriorated by simulated salivary esterases, as indicated by the greater depth of bacterial ingress and more bacterial biomass of biofilm along the interface. However, this process could be modulated by using different restorative materials and MMPs inhibition. This project elucidated the mechanistic interaction between oral bacteria and restorative materials and established a new, in vitro, and physiologically relevant model to assess the effect of material chemistry, properties, and application modes on bacterial penetration and biofilm formation. These findings offer the oral health community practical ways to reduce secondary caries by altering material composition and restorative procedures.

Mapping of medical acronyms and initialisms to Medical Subject Headings (MeSH) across selected systems

PubMed Central

Shultz, Mary

2006-01-01

Introduction: Given the common use of acronyms and initialisms in the health sciences, searchers may be entering these abbreviated terms rather than full phrases when searching online systems. The purpose of this study is to evaluate how various MEDLINE Medical Subject Headings (MeSH) interfaces map acronyms and initialisms to the MeSH vocabulary. Methods: The interfaces used in this study were: the PubMed MeSH database, the PubMed Automatic Term Mapping feature, the NLM Gateway Term Finder, and Ovid MEDLINE. Acronyms and initialisms were randomly selected from 2 print sources. The test data set included 415 randomly selected acronyms and initialisms whose related meanings were found to be MeSH terms. Each acronym and initialism was entered into each MEDLINE MeSH interface to determine if it mapped to the corresponding MeSH term. Separately, 46 commonly used acronyms and initialisms were tested. Results: While performance differed widely, the success rates were low across all interfaces for the randomly selected terms. The common acronyms and initialisms tested at higher success rates across the interfaces, but the differences between the interfaces remained. Conclusion: Online interfaces do not always map medical acronyms and initialisms to their corresponding MeSH phrases. This may lead to inaccurate results and missed information if acronyms and initialisms are used in search strategies. PMID:17082832

An Airbus arrives at KSC with third MPLM

NASA Technical Reports Server (NTRS)

2001-01-01

An Airbus '''Beluga''' air cargo plane, The Super Transporter, lands at KSC's Shuttle Landing Facility. Its cargo, from the factory of Alenia Aerospazio in Turin, Italy, is the Italian Space Agency's Multi-Purpose Logistics Module Donatello, the third of three for the International Space Station. The module will be transported to the Space Station Processing Facility for processing. Among the activities for the payload test team are integrated electrical tests with other Station elements in the SSPF, leak tests, electrical and software compatibility tests with the Space Shuttle (using the Cargo Integrated Test equipment) and an Interface Verification Test once the module is installed in the Space Shuttle's payload bay at the launch pad. The most significant mechanical task to be performed on Donatello in the SSPF is the installation and outfitting of the racks for carrying the various experiments and cargo.

An Airbus arrives at KSC with third MPLM

NASA Technical Reports Server (NTRS)

2001-01-01

An Airbus '''Beluga''' air cargo plane, The Super Transporter, arrives at KSC's Shuttle Landing Facility from the factory of Alenia Aerospazio in Turin, Italy. Its cargo is the Italian Space Agency's Multi-Purpose Logistics Module Donatello, the third of three for the International Space Station. The module will be transported to the Space Station Processing Facility for processing. Among the activities for the payload test team are integrated electrical tests with other Station elements in the SSPF, leak tests, electrical and software compatibility tests with the Space Shuttle (using the Cargo Integrated Test equipment) and an Interface Verification Test once the module is installed in the Space Shuttle's payload bay at the launch pad. The most significant mechanical task to be performed on Donatello in the SSPF is the installation and outfitting of the racks for carrying the various experiments and cargo.

Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Test act system validation

NASA Technical Reports Server (NTRS)

1985-01-01

The primary objective of the Test Active Control Technology (ACT) System laboratory tests was to verify and validate the system concept, hardware, and software. The initial lab tests were open loop hardware tests of the Test ACT System as designed and built. During the course of the testing, minor problems were uncovered and corrected. Major software tests were run. The initial software testing was also open loop. These tests examined pitch control laws, wing load alleviation, signal selection/fault detection (SSFD), and output management. The Test ACT System was modified to interface with the direct drive valve (DDV) modules. The initial testing identified problem areas with DDV nonlinearities, valve friction induced limit cycling, DDV control loop instability, and channel command mismatch. The other DDV issue investigated was the ability to detect and isolate failures. Some simple schemes for failure detection were tested but were not completely satisfactory. The Test ACT System architecture continues to appear promising for ACT/FBW applications in systems that must be immune to worst case generic digital faults, and be able to tolerate two sequential nongeneric faults with no reduction in performance. The challenge in such an implementation would be to keep the analog element sufficiently simple to achieve the necessary reliability.

Test Program for Assessing Vulnerability of Industrial Equipment to Nuclear Air Blast.

DTIC Science & Technology

1983-10-01

PROJECT. TASK 4Scientific Servic, Inc. AREA & WORK UNIT NUMBERS 517 East Bayshore Work Unit 1124F Redwood City, CA 94063___ __________ 11. CONTROLLING ...vulnerability, but perhaps less expensive, to be selected and substituted, with an eye to cost control . 5. MODELING AND SCALING CONSIDERATIONS Reiterating...behavior and properties of the test items and Interfaces that control behavior (e4g., test objects/flow field, test objects/interfacing surface of

Incorporating contact angles in the surface tension force with the ACES interface curvature scheme

NASA Astrophysics Data System (ADS)

Owkes, Mark

2017-11-01

In simulations of gas-liquid flows interacting with solid boundaries, the contact line dynamics effect the interface motion and flow field through the surface tension force. The surface tension force is directly proportional to the interface curvature and the problem of accurately imposing a contact angle must be incorporated into the interface curvature calculation. Many commonly used algorithms to compute interface curvatures (e.g., height function method) require extrapolating the interface, with defined contact angle, into the solid to allow for the calculation of a curvature near a wall. Extrapolating can be an ill-posed problem, especially in three-dimensions or when multiple contact lines are near each other. We have developed an accurate methodology to compute interface curvatures that allows for contact angles to be easily incorporated while avoiding extrapolation and the associated challenges. The method, known as Adjustable Curvature Evaluation Scale (ACES), leverages a least squares fit of a polynomial to points computed on the volume-of-fluid (VOF) representation of the gas-liquid interface. The method is tested by simulating canonical test cases and then applied to simulate the injection and motion of water droplets in a channel (relevant to PEM fuel cells).

NAS (Host/ARTS) IIIA to VME Modem Interface ATC Interface Hardware Manual

DOT National Transportation Integrated Search

1990-10-01

This document is reference material for personnel using the National Airspace : System (NAS) (HOST or ARTS IIIA) Air Traffic Control (ATC) Interface Subsystem. : It was originally developed to be part of the Data Link Test and Analysis System : (DATA...

Building Materials from Colloidal Nanocrystal Assemblies: Molecular Control of Solid/Solid Interfaces in Nanostructured Tetragonal ZrO 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, Santosh; Silva, Tiago F.; Bobbitt, Jonathan M.

We describe in this paper a bottom-up approach to control the composition of solid/solid interfaces in nanostructured materials, and we test its effectiveness on tetragonal ZrO 2, an inorganic phase of great technological significance. Colloidal nanocrystals capped with trioctylphosphine oxide (TOPO) or oleic acid (OA) are deposited, and the organic fraction of the ligands is selectively etched with O 2 plasma. The interfaces in the resulting all-inorganic colloidal nanocrystal assemblies are either nearly bare (for OA-capped nanocrystals) or terminated with phosphate groups (for TOPO-capped nanocrystals) resulting from the reaction of phosphine oxide groups with plasma species. The chemical modification ofmore » the interfaces has extensive effects on the thermodynamics and kinetics of the material. Different growth kinetics indicate different rate limiting processes of growth (surface diffusion for the phosphate-terminated surfaces and dissolution for the “bare” surfaces). Phosphate termination led to a higher activation energy of growth, and a 3-fold reduction in interfacial energy, and facilitated significantly the conversion of the tetragonal phase into the monoclinic phase. Finally, films devoid of residual ligands persisted in the tetragonal phase at temperatures as high as 900 °C for 24 h.« less

Donor-Control of Scavenging Food Webs at the Land-Ocean Interface.

PubMed

Schlacher, Thomas A; Strydom, Simone; Connolly, Rod M; Schoeman, David

2013-01-01

Food webs near the interface of adjacent ecosystems are potentially subsidised by the flux of organic matter across system boundaries. Such subsidies, including carrion of marine provenance, are predicted to be instrumental on open-coast sandy shores where in situ productivity is low and boundaries are long and highly permeable to imports from the sea. We tested the effect of carrion supply on the structure of consumer dynamics in a beach-dune system using broad-scale, repeated additions of carcasses at the strandline of an exposed beach in eastern Australia. Carrion inputs increased the abundance of large invertebrate scavengers (ghost crabs, Ocypode spp.), a numerical response most strongly expressed by the largest size-class in the population, and likely due to aggregative behaviour in the short term. Consumption of carrion at the beach-dune interface was rapid and efficient, driven overwhelmingly by facultative avian scavengers. This guild of vertebrate scavengers comprises several species of birds of prey (sea eagles, kites), crows and gulls, which reacted strongly to concentrations of fish carrion, creating hotspots of intense scavenging activity along the shoreline. Detection of carrion effects at several trophic levels suggests that feeding links arising from carcasses shape the architecture and dynamics of food webs at the land-ocean interface.

Soft, curved electrode systems capable of integration on the auricle as a persistent brain–computer interface

PubMed Central

Norton, James J. S.; Lee, Dong Sup; Lee, Jung Woo; Lee, Woosik; Kwon, Ohjin; Won, Phillip; Jung, Sung-Young; Cheng, Huanyu; Jeong, Jae-Woong; Akce, Abdullah; Umunna, Stephen; Na, Ilyoun; Kwon, Yong Ho; Wang, Xiao-Qi; Liu, ZhuangJian; Paik, Ungyu; Huang, Yonggang; Bretl, Timothy; Yeo, Woon-Hong; Rogers, John A.

2015-01-01

Recent advances in electrodes for noninvasive recording of electroencephalograms expand opportunities collecting such data for diagnosis of neurological disorders and brain–computer interfaces. Existing technologies, however, cannot be used effectively in continuous, uninterrupted modes for more than a few days due to irritation and irreversible degradation in the electrical and mechanical properties of the skin interface. Here we introduce a soft, foldable collection of electrodes in open, fractal mesh geometries that can mount directly and chronically on the complex surface topology of the auricle and the mastoid, to provide high-fidelity and long-term capture of electroencephalograms in ways that avoid any significant thermal, electrical, or mechanical loading of the skin. Experimental and computational studies establish the fundamental aspects of the bending and stretching mechanics that enable this type of intimate integration on the highly irregular and textured surfaces of the auricle. Cell level tests and thermal imaging studies establish the biocompatibility and wearability of such systems, with examples of high-quality measurements over periods of 2 wk with devices that remain mounted throughout daily activities including vigorous exercise, swimming, sleeping, and bathing. Demonstrations include a text speller with a steady-state visually evoked potential-based brain–computer interface and elicitation of an event-related potential (P300 wave). PMID:25775550

Soft, curved electrode systems capable of integration on the auricle as a persistent brain-computer interface.

PubMed

Norton, James J S; Lee, Dong Sup; Lee, Jung Woo; Lee, Woosik; Kwon, Ohjin; Won, Phillip; Jung, Sung-Young; Cheng, Huanyu; Jeong, Jae-Woong; Akce, Abdullah; Umunna, Stephen; Na, Ilyoun; Kwon, Yong Ho; Wang, Xiao-Qi; Liu, ZhuangJian; Paik, Ungyu; Huang, Yonggang; Bretl, Timothy; Yeo, Woon-Hong; Rogers, John A

2015-03-31

Recent advances in electrodes for noninvasive recording of electroencephalograms expand opportunities collecting such data for diagnosis of neurological disorders and brain-computer interfaces. Existing technologies, however, cannot be used effectively in continuous, uninterrupted modes for more than a few days due to irritation and irreversible degradation in the electrical and mechanical properties of the skin interface. Here we introduce a soft, foldable collection of electrodes in open, fractal mesh geometries that can mount directly and chronically on the complex surface topology of the auricle and the mastoid, to provide high-fidelity and long-term capture of electroencephalograms in ways that avoid any significant thermal, electrical, or mechanical loading of the skin. Experimental and computational studies establish the fundamental aspects of the bending and stretching mechanics that enable this type of intimate integration on the highly irregular and textured surfaces of the auricle. Cell level tests and thermal imaging studies establish the biocompatibility and wearability of such systems, with examples of high-quality measurements over periods of 2 wk with devices that remain mounted throughout daily activities including vigorous exercise, swimming, sleeping, and bathing. Demonstrations include a text speller with a steady-state visually evoked potential-based brain-computer interface and elicitation of an event-related potential (P300 wave).

Building Materials from Colloidal Nanocrystal Assemblies: Molecular Control of Solid/Solid Interfaces in Nanostructured Tetragonal ZrO 2

DOE PAGES

Shaw, Santosh; Silva, Tiago F.; Bobbitt, Jonathan M.; ...

2017-08-28

We describe in this paper a bottom-up approach to control the composition of solid/solid interfaces in nanostructured materials, and we test its effectiveness on tetragonal ZrO 2, an inorganic phase of great technological significance. Colloidal nanocrystals capped with trioctylphosphine oxide (TOPO) or oleic acid (OA) are deposited, and the organic fraction of the ligands is selectively etched with O 2 plasma. The interfaces in the resulting all-inorganic colloidal nanocrystal assemblies are either nearly bare (for OA-capped nanocrystals) or terminated with phosphate groups (for TOPO-capped nanocrystals) resulting from the reaction of phosphine oxide groups with plasma species. The chemical modification ofmore » the interfaces has extensive effects on the thermodynamics and kinetics of the material. Different growth kinetics indicate different rate limiting processes of growth (surface diffusion for the phosphate-terminated surfaces and dissolution for the “bare” surfaces). Phosphate termination led to a higher activation energy of growth, and a 3-fold reduction in interfacial energy, and facilitated significantly the conversion of the tetragonal phase into the monoclinic phase. Finally, films devoid of residual ligands persisted in the tetragonal phase at temperatures as high as 900 °C for 24 h.« less

Donor-Control of Scavenging Food Webs at the Land-Ocean Interface

PubMed Central

Schlacher, Thomas A.; Strydom, Simone; Connolly, Rod M.; Schoeman, David

2013-01-01

Food webs near the interface of adjacent ecosystems are potentially subsidised by the flux of organic matter across system boundaries. Such subsidies, including carrion of marine provenance, are predicted to be instrumental on open-coast sandy shores where in situ productivity is low and boundaries are long and highly permeable to imports from the sea. We tested the effect of carrion supply on the structure of consumer dynamics in a beach-dune system using broad-scale, repeated additions of carcasses at the strandline of an exposed beach in eastern Australia. Carrion inputs increased the abundance of large invertebrate scavengers (ghost crabs, Ocypode spp.), a numerical response most strongly expressed by the largest size-class in the population, and likely due to aggregative behaviour in the short term. Consumption of carrion at the beach-dune interface was rapid and efficient, driven overwhelmingly by facultative avian scavengers. This guild of vertebrate scavengers comprises several species of birds of prey (sea eagles, kites), crows and gulls, which reacted strongly to concentrations of fish carrion, creating hotspots of intense scavenging activity along the shoreline. Detection of carrion effects at several trophic levels suggests that feeding links arising from carcasses shape the architecture and dynamics of food webs at the land-ocean interface. PMID:23826379

Development of a Regenerative Peripheral Nerve Interface for Control of a Neuroprosthetic Limb

PubMed Central

Frost, Christopher M.; Martin, David C.; Larkin, Lisa M.

2016-01-01

Background. The purpose of this experiment was to develop a peripheral nerve interface using cultured myoblasts within a scaffold to provide a biologically stable interface while providing signal amplification for neuroprosthetic control and preventing neuroma formation. Methods. A Regenerative Peripheral Nerve Interface (RPNI) composed of a scaffold and cultured myoblasts was implanted on the end of a divided peroneal nerve in rats (n = 25). The scaffold material consisted of either silicone mesh, acellular muscle, or acellular muscle with chemically polymerized poly(3,4-ethylenedioxythiophene) conductive polymer. Average implantation time was 93 days. Electrophysiological tests were performed at endpoint to determine RPNI viability and ability to transduce neural signals. Tissue samples were examined using both light microscopy and immunohistochemistry. Results. All implanted RPNIs, regardless of scaffold type, remained viable and displayed robust vascularity. Electromyographic activity and stimulated compound muscle action potentials were successfully recorded from all RPNIs. Physiologic efferent motor action potentials were detected from RPNIs in response to sensory foot stimulation. Histology and transmission electron microscopy revealed mature muscle fibers, axonal regeneration without neuroma formation, neovascularization, and synaptogenesis. Desmin staining confirmed the preservation and maturation of myoblasts within the RPNIs. Conclusions. RPNI demonstrates significant myoblast maturation, innervation, and vascularization without neuroma formation. PMID:27294122

Soft, curved electrode systems capable of integration on the auricle as a persistent brain–computer interface

DOE PAGES

Norton, James J. S.; Lee, Dong Sup; Lee, Jung Woo; ...

2015-03-16

Some recent advances in electrodes for noninvasive recording of electroencephalograms expand opportunities collecting such data for diagnosis of neurological disorders and brain–computer interfaces. Existing technologies, but, cannot be used effectively in continuous, uninterrupted modes for more than a few days due to irritation and irreversible degradation in the electrical and mechanical properties of the skin interface. We introduce a soft, foldable collection of electrodes in open, fractal mesh geometries that can mount directly and chronically on the complex surface topology of the auricle and the mastoid, to provide high-fidelity and long-term capture of electroencephalograms in ways that avoid any significantmore » thermal, electrical, or mechanical loading of the skin. Experimental and computational studies establish the fundamental aspects of the bending and stretching mechanics that enable this type of intimate integration on the highly irregular and textured surfaces of the auricle. Furthermore, cell level tests and thermal imaging studies establish the biocompatibility and wearability of such systems, with examples of high-quality measurements over periods of 2 wk with devices that remain mounted throughout daily activities including vigorous exercise, swimming, sleeping, and bathing. Demonstrations include a text speller with a steady-state visually evoked potential-based brain–computer interface and elicitation of an event-related potential (P300 wave).« less

Activity and Stability of (Pr 1-xNd x) 2NiO 4 as Cathodes for Solid Oxide Fuel Cells: Part V. In Situ Studies of Phase Evolution

DOE PAGES

Dogdibegovic, Emir; Alabri, Nawf S.; Wright, Christopher J.; ...

2017-08-12

This study is to complement an early report (the manuscript is attached for review purpose) on the role of interlayer on activity and performance stability in praseodymium nickelates. The aforementioned report showed a remarkable 48% increase in power density while switching from common GDC interlayer to a new interlayer chemistry (PGCO). Furthermore, a stable long-term performance was linked with suppressed reaction between the cathode and PGCO interlayer. In this article, we report in situ studies of the phase evolution. The high energy XRD studies at a synchrotron source showed fully suppressed phase transition in praseodymium nickelates with PGCO interlayer, whilemore » the electrodes on the GDC interlayer undergo substantial phase transformation. Furthermore, in operando and post-test XRD analyses shown fully suppressed structural changes in electrodes operated in full cells at 750°C and 0.80 V for 500 hours. SEM-EDS analysis showed that the formation of PrO x at the cathode-interlayer interface may play a role in a decrease of mechanical integrity of the interfaces, due to thermal expansion mismatch, leading to a local stress between the two phases. Furthermore, phase evolution at a narrow interface may propagate toward the electrode bulk, leading to structural changes Q1 and performance degradation.« less

Activity and Stability of (Pr 1-xNd x) 2NiO 4 as Cathodes for Solid Oxide Fuel Cells: Part V. In Situ Studies of Phase Evolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dogdibegovic, Emir; Alabri, Nawf S.; Wright, Christopher J.

This study is to complement an early report (the manuscript is attached for review purpose) on the role of interlayer on activity and performance stability in praseodymium nickelates. The aforementioned report showed a remarkable 48% increase in power density while switching from common GDC interlayer to a new interlayer chemistry (PGCO). Furthermore, a stable long-term performance was linked with suppressed reaction between the cathode and PGCO interlayer. In this article, we report in situ studies of the phase evolution. The high energy XRD studies at a synchrotron source showed fully suppressed phase transition in praseodymium nickelates with PGCO interlayer, whilemore » the electrodes on the GDC interlayer undergo substantial phase transformation. Furthermore, in operando and post-test XRD analyses shown fully suppressed structural changes in electrodes operated in full cells at 750°C and 0.80 V for 500 hours. SEM-EDS analysis showed that the formation of PrO x at the cathode-interlayer interface may play a role in a decrease of mechanical integrity of the interfaces, due to thermal expansion mismatch, leading to a local stress between the two phases. Furthermore, phase evolution at a narrow interface may propagate toward the electrode bulk, leading to structural changes Q1 and performance degradation.« less

Suppressed Sr segregation and performance of directly assembled La0.6Sr0.4Co0.2Fe0.8O3-δ oxygen electrode on Y2O3-ZrO2 electrolyte of solid oxide electrolysis cells

NASA Astrophysics Data System (ADS)

Ai, Na; He, Shuai; Li, Na; Zhang, Qi; Rickard, William D. A.; Chen, Kongfa; Zhang, Teng; Jiang, San Ping

2018-04-01

Active and stable oxygen electrode is probably the most important in the development of solid oxide electrolysis cells (SOECs) technologies. Herein, we report the successful development of mixed ionic and electronic conducting (MIEC) La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) perovskite oxides directly assembled on barrier-layer-free yttria-stabilized zirconia (YSZ) electrolyte as highly active and stable oxygen electrodes of SOECs. Electrolysis polarization effectively induces the formation of electrode/electrolyte interface, similar to that observed under solid oxide fuel cell (SOFC) operation conditions. However, in contrast to the significant performance decay under SOFC operation conditions, the cell with directly assembled LSCF oxygen electrodes shows excellent stability, tested for 300 h at 0.5 A cm-2 and 750 °C under SOEC operation conditions. Detailed microstructure and phase analysis reveal that Sr segregation is inevitable for LSCF electrode, but anodic polarization substantially suppresses Sr segregation and migration to the electrode/electrolyte interface, leading to the formation of stable and efficient electrode/electrolyte interface for water and CO2 electrolysis under SOECs operation conditions. The present study demonstrates the feasibility of using directly assembled MIEC cobaltite based oxygen electrodes on barrier-layer-free YSZ electrolyte of SOECs.

Self-Observation Model Employing an Instinctive Interface for Classroom Active Learning

ERIC Educational Resources Information Center

Chen, Gwo-Dong; Nurkhamid; Wang, Chin-Yeh; Yang, Shu-Han; Chao, Po-Yao

2014-01-01

In a classroom, obtaining active, whole-focused, and engaging learning results from a design is often difficult. In this study, we propose a self-observation model that employs an instinctive interface for classroom active learning. Students can communicate with virtual avatars in the vertical screen and can react naturally according to the…

Does this interface make my sensor look bad? Basic principles for designing usable, useful interfaces for sensor technology operators

NASA Astrophysics Data System (ADS)

McNamara, Laura A.; Berg, Leif; Butler, Karin; Klein, Laura

2017-05-01

Even as remote sensing technology has advanced in leaps and bounds over the past decade, the remote sensing community lacks interfaces and interaction models that facilitate effective human operation of our sensor platforms. Interfaces that make great sense to electrical engineers and flight test crews can be anxiety-inducing to operational users who lack professional experience in the design and testing of sophisticated remote sensing platforms. In this paper, we reflect on an 18-month collaboration which our Sandia National Laboratory research team partnered with an industry software team to identify and fix critical issues in a widely-used sensor interface. Drawing on basic principles from cognitive and perceptual psychology and interaction design, we provide simple, easily learned guidance for minimizing common barriers to system learnability, memorability, and user engagement.

Earthdata User Interface Patterns: Building Usable Web Interfaces Through a Shared UI Pattern Library

NASA Astrophysics Data System (ADS)

Siarto, J.

2014-12-01

As more Earth science software tools and services move to the web--the design and usability of those tools become ever more important. A good user interface is becoming expected and users are becoming increasingly intolerant of websites and web applications that work against them. The Earthdata UI Pattern Library attempts to give these scientists and developers the design tools they need to make usable, compelling user interfaces without the associated overhead of using a full design team. Patterns are tested and functional user interface elements targeted specifically at the Earth science community and will include web layouts, buttons, tables, typography, iconography, mapping and visualization/graphing widgets. These UI elements have emerged as the result of extensive user testing, research and software development within the NASA Earthdata team over the past year.

Dynamic Asphaltene-Stearic Acid Competition at the Oil-Water Interface.

PubMed

Sauerer, Bastian; Stukan, Mikhail; Buiting, Jan; Abdallah, Wael; Andersen, Simon

2018-05-15

Interfacial tension (IFT) is one of the major parameters which govern the fluid flow in oil production and recovery. This paper investigates the interfacial activity of different natural surfactants found in crude oil. The main objective was to better understand the competition between carboxylic acids and asphaltenes on toluene/water interfaces. Dynamic IFT was measured for water-in-oil pendant drops contrary to most studies using oil-in-water drops. Stearic acid (SA) was used as model compound for surface-active carboxylic acids in crude. The influence of concentration of these species on dynamic IFT between model oil and deionized water was examined. The acid concentrations were of realistic values (total acid number 0.1 to 2 mg KOH/g oil) while asphaltene concentrations were low and set between 10 and 100 ppm. In mixtures, the initial surface pressure was entirely determined by the SA content while asphaltenes showed a slow initial diffusion to the interface followed by increased adsorption at longer times. The final surface pressure was higher for asphaltenes compared to SA, but for binaries, the final surface pressure was always lower than the sum of the individuals. At high SA concentration, surface pressures of mixtures were dominated entirely by the SA, although, Langmuir isotherm analysis shows that asphaltenes bind to the interface 200-250 times stronger than SA. The surface area/molecule for both SA and asphaltenes were found to be larger than the values reported in recent literature. Various approaches to dynamic surface adsorption were tested, showing that apparent diffusivity of asphaltenes is very low, in agreement with other works. Hence, the adsorption is apparently under barrier control. A possible hypothesis is that at the initial phase of the experiment and at lower concentration of asphaltenes, the interface is occupied by stearic acid molecules forming a dense layer of hydrocarbon chains that may repel the asphaltenes.

Haptic fMRI: using classification to quantify task-correlated noise during goal-directed reaching motions.

PubMed

Menon, Samir; Quigley, Paul; Yu, Michelle; Khatib, Oussama

2014-01-01

Neuroimaging artifacts in haptic functional magnetic resonance imaging (Haptic fMRI) experiments have the potential to induce spurious fMRI activation where there is none, or to make neural activation measurements appear correlated across brain regions when they are actually not. Here, we demonstrate that performing three-dimensional goal-directed reaching motions while operating Haptic fMRI Interface (HFI) does not create confounding motion artifacts. To test for artifacts, we simultaneously scanned a subject's brain with a customized soft phantom placed a few centimeters away from the subject's left motor cortex. The phantom captured task-related motion and haptic noise, but did not contain associated neural activation measurements. We quantified the task-related information present in fMRI measurements taken from the brain and the phantom by using a linear max-margin classifier to predict whether raw time series data could differentiate between motion planning or reaching. fMRI measurements in the phantom were uninformative (2σ, 45-73%; chance=50%), while those in primary motor, visual, and somatosensory cortex accurately classified task-conditions (2σ, 90-96%). We also localized artifacts due to the haptic interface alone by scanning a stand-alone fBIRN phantom, while an operator performed haptic tasks outside the scanner's bore with the interface at the same location. The stand-alone phantom had lower temporal noise and had similar mean classification but a tighter distribution (bootstrap Gaussian fit) than the brain phantom. Our results suggest that any fMRI measurement artifacts for Haptic fMRI reaching experiments are dominated by actual neural responses.

Development of a multi-behavioral mHealth app for women smokers

PubMed Central

Armin, Julie; Johnson, Thienne; Hingle, Melanie; Giacobbi, Peter; Gordon, Judith S.

2017-01-01

Objective This paper describes the development of the See Me Smoke-Free™ (SMSF) mobile health application, which uses guided imagery to support women in smoking cessation, eating a healthy diet, and increasing physical activity. Materials and Methods Focus group discussions, with member checks, were conducted to refine the intervention content and app user interface. Data related to the context of app deployment were collected via user testing sessions and internal quality control testing, which identified and addressed functionality issues, content problems, and bugs. Results Interactive app features include playback of guided imagery audio files, notification pop-ups, award-sharing on social media, a tracking calendar, content resources, and direct call to the local tobacco quitline. Focus groups helped design the user interface, and identified several themes for incorporation into app content, including positivity, the rewards of smoking cessation, and the integrated benefits maintaining a healthy lifestyle. User testing improved app functionality and usability on many Android phone models. Discussion Changes to the app content and function were made iteratively by the development team as a result of focus group and user testing. Despite extensive internal and user testing, unanticipated data collection and reporting issues emerged during deployment due to the variety of Android software and hardware, but also due to individual phone settings and use. Conclusion Focus group interviews helped thematically frame the intervention and maximize user engagement. Testing caught many bugs and usability concerns, but missed some of the data transmission problems encountered during deployment. PMID:28121240

The design of an intelligent human-computer interface for the test, control and monitor system

NASA Technical Reports Server (NTRS)

Shoaff, William D.

1988-01-01

The graphical intelligence and assistance capabilities of a human-computer interface for the Test, Control, and Monitor System at Kennedy Space Center are explored. The report focuses on how a particular commercial off-the-shelf graphical software package, Data Views, can be used to produce tools that build widgets such as menus, text panels, graphs, icons, windows, and ultimately complete interfaces for monitoring data from an application; controlling an application by providing input data to it; and testing an application by both monitoring and controlling it. A complete set of tools for building interfaces is described in a manual for the TCMS toolkit. Simple tools create primitive widgets such as lines, rectangles and text strings. Intermediate level tools create pictographs from primitive widgets, and connect processes to either text strings or pictographs. Other tools create input objects; Data Views supports output objects directly, thus output objects are not considered. Finally, a set of utilities for executing, monitoring use, editing, and displaying the content of interfaces is included in the toolkit.

An Aquatic Acoustic Metrics Interface Utility for Underwater Sound Monitoring and Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Huiying; Halvorsen, Michele B.; Deng, Zhiqun

Fishes and other marine mammals suffer a range of potential effects from intense sound sources generated by anthropogenic underwater processes such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording devices (USR) were built to monitor the acoustic sound pressure waves generated by those anthropogenic underwater activities, so the relevant processing software becomes indispensable for analyzing the audio files recorded by these USRs. However, existing software packages did not meet performance and flexibility requirements. In this paper, we provide a detailed description of a new software package, named Aquatic Acoustic Metrics Interface (AAMI), which is a Graphicalmore » User Interface (GUI) designed for underwater sound monitoring and analysis. In addition to the general functions, such as loading and editing audio files recorded by USRs, the software can compute a series of acoustic metrics in physical units, monitor the sound's influence on fish hearing according to audiograms from different species of fishes and marine mammals, and batch process the sound files. The detailed applications of the software AAMI will be discussed along with several test case scenarios to illustrate its functionality.« less

Development and Feasibility Testing of a Smartphone Intervention to Improve Adherence to Antipsychotic Medications.

PubMed

Kreyenbuhl, Julie; Record, Elizabeth J; Himelhoch, Seth; Charlotte, Melanie; Palmer-Bacon, Jessica; Dixon, Lisa B; Medoff, Deborah R; Li, Lan

2016-07-25

Approximately 60% of individuals with schizophrenia do not take their antipsychotic medications as prescribed, and nonadherence is associated with exacerbation of psychotic symptoms, increased hospital and emergency room use, and increased healthcare costs. Behavioral-tailoring strategies that incorporate medication taking into the daily routine and use environmental supports have shown promise as adherence-enhancing interventions. Informed by the Information-Motivation-Behavioral (IMB) Skills Model and using the iterative process of user-centered design, we collaborated with individuals with schizophrenia and psychiatrists to develop an interactive smartphone application and web-based clinician interface, MedActive, for improving adherence to oral antipsychotic treatment. MedActive facilitates the active involvement of individuals with schizophrenia in managing their antipsychotic medication regimen by providing automated reminders for medication administration and tailored motivational feedback to encourage adherence, and by displaying user-friendly results of daily ecological momentary assessments (EMAs) of medication adherence, positive psychotic symptoms, and medication side effects for individuals and their psychiatrists. In a 2-week open trial completed by 7 individuals with schizophrenia and their psychiatrists, MedActive was determined to be both feasible and acceptable, with patient participants responding to 80% of all scheduled EMAs and providing positive evaluations of their use of the application. Psychiatrist participants were interested in viewing the information provided on the MedActive clinician interface, but cited practical barriers to regularly accessing it and integrating into their daily practice.

The impact of interface bonding efficiency on high-burnup spent nuclear fuel dynamic performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Hao; Wang, Jy-An John; Wang, Hong

Finite element analysis (FEA) was used to investigate the impact of interfacial bonding efficiency at pellet-pellet and pellet-clad interfaces of high-burnup (HBU) spent nuclear fuel (SNF) on system dynamic performance. Bending moments M were applied to FEA model to evaluate the system responses. From bending curvature, κ, flexural rigidity EI can be estimated as EI = M/κ. The FEA simulation results were benchmarked with experimental results from cyclic integrated reversal bending fatigue test (CIRFT) of HBR fuel rods. The consequence of interface debonding between fuel pellets and cladding is a redistribution of the loads carried by the fuel pellets tomore » the clad, which results in a reduction in composite rod system flexural rigidity. Furthermore, the interface bonding efficiency at the pellet-pellet and pellet-clad interfaces can significantly dictate the SNF system dynamic performance. With the consideration of interface bonding efficiency, the HBU SNF fuel property was estimated with CIRFT test data.« less

The impact of interface bonding efficiency on high-burnup spent nuclear fuel dynamic performance

DOE PAGES

Jiang, Hao; Wang, Jy-An John; Wang, Hong

2016-09-26

Finite element analysis (FEA) was used to investigate the impact of interfacial bonding efficiency at pellet-pellet and pellet-clad interfaces of high-burnup (HBU) spent nuclear fuel (SNF) on system dynamic performance. Bending moments M were applied to FEA model to evaluate the system responses. From bending curvature, κ, flexural rigidity EI can be estimated as EI = M/κ. The FEA simulation results were benchmarked with experimental results from cyclic integrated reversal bending fatigue test (CIRFT) of HBR fuel rods. The consequence of interface debonding between fuel pellets and cladding is a redistribution of the loads carried by the fuel pellets tomore » the clad, which results in a reduction in composite rod system flexural rigidity. Furthermore, the interface bonding efficiency at the pellet-pellet and pellet-clad interfaces can significantly dictate the SNF system dynamic performance. With the consideration of interface bonding efficiency, the HBU SNF fuel property was estimated with CIRFT test data.« less

Redox chemistry at liquid/liquid interfaces

NASA Technical Reports Server (NTRS)

Volkov, A. G.; Deamer, D. W.

1997-01-01

The interface between two immiscible liquids with immobilized photosynthetic pigments can serve as the simplest model of a biological membrane convenient for the investigation of photoprocesses accompanied by spatial separation of charges. As it follows from thermodynamics, if the resolvation energies of substrates and products are very different, the interface between two immiscible liquids may act as a catalyst. Theoretical aspects of charge transfer reactions at oil/water interfaces are discussed. Conditions under which the free energy of activation of the interfacial reaction of electron transfer decreases are established. The activation energy of electron transfer depends on the charges of the reactants and dielectric permittivity of the non-aqueous phase. This can be useful when choosing a pair of immiscible solvents to decrease the activation energy of the reaction in question or to inhibit an undesired process. Experimental interfacial catalytic systems are discussed. Amphiphilic molecules such as chlorophyll or porphyrins were studied as catalysts of electron transfer reactions at the oil/water interface.

Amino acids at water-vapor interfaces: surface activity and orientational ordering.

PubMed

Vöhringer-Martinez, Esteban; Toro-Labbé, Alejandro

2010-10-14

The surface activity and orientational ordering of amino acids at water-vapor interfaces were studied with molecular dynamics simulations in combination with thermodynamic integration and umbrella sampling. Asparagine, representing amino acids with polar side chains, displays no surface activity. Tryptophan, in contrast, with its hydrophobic indole ring as side chain unveils a free energy minimum at the water-vapor interface, which lies 6 kJ/mol under the hydration free energy. To study the orientational ordering of tryptophan along the interface, the order parameter was calculated. At the free energy minimum and at the Gibbs dividing surface, the order parameter reveals a parallel alignment of the indole ring with the water surface exposing the π-system to electrophiles in the hydrophobic phase and indicating polarization dependent spectroscopy. In the vicinity of this position a perpendicular orientation is obtained. The surface excess, calculated from the potential of mean force along the interface, is in excellent agreement with experimental measurements.

An experimental animal model of aseptic loosening of hip prostheses in sheep to study early biochemical changes at the interface membrane

PubMed Central

El-Warrak, Alexander O; Olmstead, Marvin; Schneider, Rebecca; Meinel, Lorenz; Bettschart-Wolfisberger, Regula; Akens, Margarete K; Auer, Joerg; von Rechenberg, Brigitte

2004-01-01

Background Aseptic loosening of hip prosthesis as it occurs in clinical cases in human patients was attributed to wear particles of the implants, the response of the tissue dominated by macrophages and the production of inflammatory mediators and matrix degrading enzymes; however, the cascade of events initiating the process and their interaction regarding the time course is still open and discussed controversially. Therefore, the goal of this study was to establish an experimental animal model in sheep allowing to follow the cascade of early mechanical and biochemical events within the interface membrane and study the sequence of how they contribute to the pathological bone resorption necessary for aseptic loosening of the implant. Methods A cemented modular system (Biomedtrix) was used as a hip replacement in 24 adult Swiss Alpine sheep, with one group receiving a complete cement mantle as controls (n = 12), and the other group a cement mantle with a standardized, lateral, primary defect in the cement mantle (n = 12). Animals were followed over time for 2 and 8.5 months (n = 6 each). After sacrifice, samples from the interface membranes were harvested from five different regions of the femur and joint capsule. Explant cell cultures were performed and supernatant of cultures were tested and assayed for nitric oxide, prostaglandin E2, caseinolytic and collagenolytic activity. RNA extraction and quantification were performed for inducible nitric oxide synthase, cyclooxygenase-2, interleukin 1, and interleukin 6. Overall differences between groups and time periods and interactions thereof were calculated using a factorial analysis of variance (ANOVA). Results The development of an interface membrane was noticed in both groups at both time points. However, in the controls the interface membrane regressed in thickness and biological activity, while both variables increased in the experimental group with the primary cement mantle defect over time. Nitric oxide (NO) and PGE2 concentrations were higher in the 8.5 months group (P < 0.0001) compared to the 2 months group with a tendency for the unstable group to have higher concentrations. The same was true for collagenolytic activity (P = 0.05), but not for caseinolytic activity that decreased over time (P < 0.0001). Conclusion In this study, a primary cement mantle defect of the femoral shaft elicited biomechanical instability and biochemical changes over time in an experimental animal study in sheep, that resembled the changes described at the bone cement-interface in aseptic loosening of total hip prosthesis in humans. The early biochemical changes may well explain the pathologic bone resorption and formation of an interface membrane as is observed in clinical cases. This animal model may aid in future studies aiming at prevention of aseptic loosening of hip prosthesis and reflect some aspects of the pathogenesis involved. PMID:15113432

Catalysis by a de novo zinc-mediated protein interface: implications for natural enzyme evolution and rational enzyme engineering.

PubMed

Der, Bryan S; Edwards, David R; Kuhlman, Brian

2012-05-08

Here we show that a recent computationally designed zinc-mediated protein interface is serendipitously capable of catalyzing carboxyester and phosphoester hydrolysis. Although the original motivation was to design a de novo zinc-mediated protein-protein interaction (called MID1-zinc), we observed in the homodimer crystal structure a small cleft and open zinc coordination site. We investigated if the cleft and zinc site at the designed interface were sufficient for formation of a primitive active site that can perform hydrolysis. MID1-zinc hydrolyzes 4-nitrophenyl acetate with a rate acceleration of 10(5) and a k(cat)/K(M) of 630 M(-1) s(-1) and 4-nitrophenyl phosphate with a rate acceleration of 10(4) and a k(cat)/K(M) of 14 M(-1) s(-1). These rate accelerations by an unoptimized active site highlight the catalytic power of zinc and suggest that the clefts formed by protein-protein interactions are well-suited for creating enzyme active sites. This discovery has implications for protein evolution and engineering: from an evolutionary perspective, three-coordinated zinc at a homodimer interface cleft represents a simple evolutionary path to nascent enzymatic activity; from a protein engineering perspective, future efforts in de novo design of enzyme active sites may benefit from exploring clefts at protein interfaces for active site placement.

A New Approach in Force-Limited Vibration Testing of Flight Hardware

NASA Technical Reports Server (NTRS)

Kolaini, Ali R.; Kern, Dennis L.

2012-01-01

The force-limited vibration test approaches discussed in NASA-7004C were developed to reduce overtesting associated with base shake vibration tests of aerospace hardware where the interface responses are excited coherently. This handbook outlines several different methods of specifying the force limits. The rationale for force limiting is based on the disparity between the impedances of typical aerospace mounting structures and the large impedances of vibration test shakers when the interfaces in general are coherently excited. Among these approaches, the semi-empirical method is presently the most widely used method to derive the force limits. The inclusion of the incoherent excitation of the aerospace structures at mounting interfaces has not been accounted for in the past and provides the basis for more realistic force limits for qualifying the hardware using shaker testing. In this paper current methods for defining the force limiting specifications discussed in the NASA handbook are reviewed using data from a series of acoustic and vibration tests. A new approach based on considering the incoherent excitation of the structural mounting interfaces using acoustic test data is also discussed. It is believed that the new approach provides much more realistic force limits that may further remove conservatism inherent in shaker vibration testing not accounted for by methods discussed in the NASA handbook. A discussion on using FEM/BEM analysis to obtain realistic force limits for flight hardware is provided.

Tunable allosteric library of caspase-3 identifies coupling between conserved water molecules and conformational selection

PubMed Central

Maciag, Joseph J.; Mackenzie, Sarah H.; Tucker, Matthew B.; Schipper, Joshua L.; Swartz, Paul; Clark, A. Clay

2016-01-01

The native ensemble of caspases is described globally by a complex energy landscape where the binding of substrate selects for the active conformation, whereas targeting an allosteric site in the dimer interface selects an inactive conformation that contains disordered active-site loops. Mutations and posttranslational modifications stabilize high-energy inactive conformations, with mostly formed, but distorted, active sites. To examine the interconversion of active and inactive states in the ensemble, we used detection of related solvent positions to analyze 4,995 waters in 15 high-resolution (<2.0 Å) structures of wild-type caspase-3, resulting in 450 clusters with the most highly conserved set containing 145 water molecules. The data show that regions of the protein that contact the conserved waters also correspond to sites of posttranslational modifications, suggesting that the conserved waters are an integral part of allosteric mechanisms. To test this hypothesis, we created a library of 19 caspase-3 variants through saturation mutagenesis in a single position of the allosteric site of the dimer interface, and we show that the enzyme activity varies by more than four orders of magnitude. Altogether, our database consists of 37 high-resolution structures of caspase-3 variants, and we demonstrate that the decrease in activity correlates with a loss of conserved water molecules. The data show that the activity of caspase-3 can be fine-tuned through globally desolvating the active conformation within the native ensemble, providing a mechanism for cells to repartition the ensemble and thus fine-tune activity through conformational selection. PMID:27681633

Tunable allosteric library of caspase-3 identifies coupling between conserved water molecules and conformational selection.

PubMed

Maciag, Joseph J; Mackenzie, Sarah H; Tucker, Matthew B; Schipper, Joshua L; Swartz, Paul; Clark, A Clay

2016-10-11

The native ensemble of caspases is described globally by a complex energy landscape where the binding of substrate selects for the active conformation, whereas targeting an allosteric site in the dimer interface selects an inactive conformation that contains disordered active-site loops. Mutations and posttranslational modifications stabilize high-energy inactive conformations, with mostly formed, but distorted, active sites. To examine the interconversion of active and inactive states in the ensemble, we used detection of related solvent positions to analyze 4,995 waters in 15 high-resolution (<2.0 Å) structures of wild-type caspase-3, resulting in 450 clusters with the most highly conserved set containing 145 water molecules. The data show that regions of the protein that contact the conserved waters also correspond to sites of posttranslational modifications, suggesting that the conserved waters are an integral part of allosteric mechanisms. To test this hypothesis, we created a library of 19 caspase-3 variants through saturation mutagenesis in a single position of the allosteric site of the dimer interface, and we show that the enzyme activity varies by more than four orders of magnitude. Altogether, our database consists of 37 high-resolution structures of caspase-3 variants, and we demonstrate that the decrease in activity correlates with a loss of conserved water molecules. The data show that the activity of caspase-3 can be fine-tuned through globally desolvating the active conformation within the native ensemble, providing a mechanism for cells to repartition the ensemble and thus fine-tune activity through conformational selection.

The acidic transcription activator Gcn4 binds the mediator subunit Gal11/Med15 using a simple protein interface forming a fuzzy complex.

PubMed

Brzovic, Peter S; Heikaus, Clemens C; Kisselev, Leonid; Vernon, Robert; Herbig, Eric; Pacheco, Derek; Warfield, Linda; Littlefield, Peter; Baker, David; Klevit, Rachel E; Hahn, Steven

2011-12-23

The structural basis for binding of the acidic transcription activator Gcn4 and one activator-binding domain of the Mediator subunit Gal11/Med15 was examined by NMR. Gal11 activator-binding domain 1 has a four-helix fold with a small shallow hydrophobic cleft at its center. In the bound complex, eight residues of Gcn4 adopt a helical conformation, allowing three Gcn4 aromatic/aliphatic residues to insert into the Gal11 cleft. The protein-protein interface is dynamic and surprisingly simple, involving only hydrophobic interactions. This allows Gcn4 to bind Gal11 in multiple conformations and orientations, an example of a "fuzzy" complex, where the Gcn4-Gal11 interface cannot be described by a single conformation. Gcn4 uses a similar mechanism to bind two other unrelated activator-binding domains. Functional studies in yeast show the importance of residues at the protein interface, define the minimal requirements for a functional activator, and suggest a mechanism by which activators bind to multiple unrelated targets. Copyright © 2011 Elsevier Inc. All rights reserved.

The crew activity planning system bus interface unit

NASA Technical Reports Server (NTRS)

Allen, M. A.

1979-01-01

The hardware and software designs used to implement a high speed parallel communications interface to the MITRE 307.2 kilobit/second serial bus communications system are described. The primary topic is the development of the bus interface unit.

SEASAT study documentation

NASA Technical Reports Server (NTRS)

1974-01-01

The proposed spacecraft consists of a bus module, containing all subsystems required for support of the sensors, and a payload module containing all of the sensor equipment. The two modules are bolted together to form the spacecraft, and electrical interfaces are accomplished via mated connectors at the interface plane. This approach permits independent parallel assembly and test operations on each module up until mating for final spacecraft integration and test operations. Proposed program schedules recognize the need to refine sensor/spacecraft interfaces prior to proceeding with procurement, reflect the lead times estimated by suppliers for delivery of equipment, reflect a comprehensive test program, and provide flexibility for unanticipated problems. The spacecraft systems are described in detail along with aerospace ground equipment, ground handling equipment, the launch vehicle, imaging radar incorporation, and systems tests.

EGSE customization for the Euclid NISP Instrument AIV/AIT activities

NASA Astrophysics Data System (ADS)

Franceschi, E.; Trifoglio, M.; Gianotti, F.; Conforti, V.; Andersen, J. J.; Stephen, J. B.; Valenziano, L.; Auricchio, N.; Bulgarelli, A.; De Rosa, A.; Fioretti, V.; Maiorano, E.; Morgante, G.; Nicastro, L.; Sortino, F.; Zoli, A.; Balestra, A.; Bonino, D.; Bonoli, C.; Bortoletto, F.; Capobianco, V.; Corcione, L.; Dal Corso, F.; Debei, S.; Di Ferdinando, D.; Dusini, S.; Farinelli, R.; Fornari, F.; Giacomini, F.; Guizzo, G. P.; Laudisio, F.; Ligori, S.; Mauri, N.; Medinaceli, E.; Patrizii, L.; Sirignano, C.; Sirri, G.; Stanco, L.; Tenti, M.; Valieri, C.; Ventura, S.

2016-07-01

The Near Infrared Spectro-Photometer (NISP) on board the Euclid ESA mission will be developed and tested at various levels of integration by using various test equipment. The Electrical Ground Support Equipment (EGSE) shall be required to support the assembly, integration, verification and testing (AIV/AIT) and calibration activities at instrument level before delivery to ESA, and at satellite level, when the NISP instrument is mounted on the spacecraft. In the case of the Euclid mission this EGSE will be provided by ESA to NISP team, in the HW/SW framework called "CCS Lite", with a possible first usage already during the Warm Electronics (WE) AIV/AIT activities. In this paper we discuss how we will customize that "CCS Lite" as required to support both the WE and Instrument test activities. This customization will primarily involve building the NISP Mission Information Base (the CCS MIB tables) by gathering the relevant data from the instrument sub-units and validating these inputs through specific tools. Secondarily, it will imply developing a suitable set of test sequences, by using uTOPE (an extension to the TCL scripting language, included in the CCS framework), in order to implement the foreseen test procedures. In addition and in parallel, custom interfaces shall be set up between the CCS and the NI-IWS (the NISP Instrument Workstation, which will be in use at any level starting from the WE activities), and also between the CCS and the TCC (the Telescope Control and command Computer, to be only and specifically used during the instrument level tests).

Development of the Computer Interface Literacy Measure.

ERIC Educational Resources Information Center

Turner, G. Marc; Sweany, Noelle Wall; Husman, Jenefer

2000-01-01

Discussion of computer literacy and the rapidly changing face of technology focuses on a study that redefined computer literacy to include competencies for using graphical user interfaces for operating systems, hypermedia applications, and the Internet. Describes the development and testing of the Computer Interface Literacy Measure with…

ESTABLISHING A LIVE CARTILAGE-ON-CARTILAGE INTERFACE FOR TRIBOLOGICAL TESTING.

PubMed

Trevino, Robert L; Stoia, Jonathan; Laurent, Michel P; Pacione, Carol A; Chubinskaya, Susan; Wimmer, Markus A

2017-03-01

Mechano-biochemical wear encompasses the tribological interplay between biological and mechanical mechanisms responsible for cartilage wear and degradation. The aim of this study was to develop and start validating a novel tribological testing system, which better resembles the natural joint environment through incorporating a live cartilage-on-cartilage articulating interface, joint specific kinematics, and the application of controlled mechanical stimuli for the measurement of biological responses in order to study the mechano-biochemical wear of cartilage. The study entailed two parts. In Part 1, the novel testing rig was used to compare two bearing systems: (a) cartilage articulating against cartilage (CoC) and (b) metal articulating against cartilage (MoC). The clinically relevant MoC, which is also a common tribological interface for evaluating cartilage wear, should produce more wear to agree with clinical observations. In Part II, the novel testing system was used to determine how wear is affected by tissue viability in live and dead CoC articulations. For both parts, bovine cartilage explants were harvested and tribologically tested for three consecutive days. Wear was defined as release of glycosaminoglycans into the media and as evaluation of the tissue structure. For Part I, we found that the live CoC articulation did not cause damage to the cartilage, to the extent of being comparable to the free swelling controls, whereas the MoC articulation caused decreased cell viability, extracellular matrix disruption, and increased wear when compared to CoC, and consistent with clinical data. These results provided confidence that this novel testing system will be adequate to screen new biomaterials for articulation against cartilage, such as in hemiarthroplasty. For Part II, the live and dead cartilage articulation yielded similar wear as determined by the release of proteoglycans and aggrecan fragments, suggesting that keeping the cartilage alive may not be essential for short term wear tests. However, the biosynthesis of glycosaminoglycans was significantly higher due to live CoC articulation than due to the corresponding live free swelling controls, indicating that articulation stimulated cell activity. Moving forward, the cell response to mechanical stimuli and the underlying mechano-biochemical wear mechanisms need to be further studied for a complete picture of tissue degradation.

KSC-01pp0934

NASA Image and Video Library

2001-04-27

KENNEDY SPACE CENTER, FLA. -- The STS-104 crew poses in front of the Joint Airlock Module in the Space Station Processing Facility. Standing, left to right, are Pilot Charles Hobaugh, Mission Specialists James Reillly, Janet Kavandi and Michael Gernhardt, and Commander Steven Lindsey. They are at KSC to continue Crew Equipment Interface Test activities such as payload familiarization. The airlock is the primary payload on their mission, scheduled to launch no earlier than June 14, 2001, from Launch Pad 39B

System interface for an integrated intelligent safety system (ISS) for vehicle applications.

PubMed

Hannan, Mahammad A; Hussain, Aini; Samad, Salina A

2010-01-01

This paper deals with the interface-relevant activity of a vehicle integrated intelligent safety system (ISS) that includes an airbag deployment decision system (ADDS) and a tire pressure monitoring system (TPMS). A program is developed in LabWindows/CVI, using C for prototype implementation. The prototype is primarily concerned with the interconnection between hardware objects such as a load cell, web camera, accelerometer, TPM tire module and receiver module, DAQ card, CPU card and a touch screen. Several safety subsystems, including image processing, weight sensing and crash detection systems, are integrated, and their outputs are combined to yield intelligent decisions regarding airbag deployment. The integrated safety system also monitors tire pressure and temperature. Testing and experimentation with this ISS suggests that the system is unique, robust, intelligent, and appropriate for in-vehicle applications.

System Interface for an Integrated Intelligent Safety System (ISS) for Vehicle Applications

PubMed Central

Hannan, Mahammad A.; Hussain, Aini; Samad, Salina A.

2010-01-01

This paper deals with the interface-relevant activity of a vehicle integrated intelligent safety system (ISS) that includes an airbag deployment decision system (ADDS) and a tire pressure monitoring system (TPMS). A program is developed in LabWindows/CVI, using C for prototype implementation. The prototype is primarily concerned with the interconnection between hardware objects such as a load cell, web camera, accelerometer, TPM tire module and receiver module, DAQ card, CPU card and a touch screen. Several safety subsystems, including image processing, weight sensing and crash detection systems, are integrated, and their outputs are combined to yield intelligent decisions regarding airbag deployment. The integrated safety system also monitors tire pressure and temperature. Testing and experimentation with this ISS suggests that the system is unique, robust, intelligent, and appropriate for in-vehicle applications. PMID:22205861

Adhesion and abrasion of surface materials in the Venusian aeolian environment

NASA Technical Reports Server (NTRS)

Marshall, John R.; Greeley, Ronald; Tucker, David; Fogleman, Guy; Hixon, Raymond

1991-01-01

In laboratory simulations of the Venusian environment, rock and mineral 'target' surfaces struck by aeolian particles develop a thin layer of accretionary material derived from the particles' attrition debris. Accretion may be (in part) a manifestation of 'cold welding', a process well known in engineering, where bonding occurs between metals at a tribological interface. Accretion on geological materials was found to occur at all Venusian surface temperatures and for all types of materials tested. First-order variations in the amount deposited by particles are related to relative attrition susceptibilities. Second-order variations relate to properties of the particle-target interface. Variations in accretion volume are apparently independent of mineral chemistry and are only weakly dependent on crystallography. The results suggest that accretion should be a fairly universal phenomenon in areas of Venus subject to aeolian activity.

Orbital operations study. Volume 2: Interfacing activities analysis. Part 2: Structural and mechanical group

NASA Technical Reports Server (NTRS)

Mattson, H. L.; Gianformaggio, A.; Anderson, N. R.

1972-01-01

The activities of the structural and mechanical activity group of the orbital operations study project are discussed. Element interfaces, alternate approaches, design concepts, operational procedures, functional requirements, design influences, and approach selection are presented. The following areas are considered: (1) mating, (2) orbital assembly, (3) separation, EOS payload deployment, and EOS payload retraction.

Interface activation and surface characteristics of Ti/TiN/HA coated sintered stainless steels

NASA Astrophysics Data System (ADS)

Choe, Han-Cheol; Ko, Yeong-Mu

2006-02-01

Interface activation and surface characteristics of Ti/TiN/HA film coated sintered stainless steels (SSS) have been investigated by electrochemical and biocompatibility tests. HA (hydroxyapatite), Ti, and Ti/TiN film coatings were applied using electron-beam deposition method (EB-PVD). Ti, Ti/TiN, and Ti/TiN/HA film coated surfaces and layers were investigated by SEM and XPS. The coated films showed micro-columnar structure, and Ti/TiN/HA films were denser than Ti or HA-only film. The corrosion resistance of the HA coating was similar to that of Ti/TiN/HA film coating when Cu content reached 4 wt.%, but the corrosion resistance of the HA coating decreased when Cu content increased from 4 wt.% in 0.9% NaCl solution. Therefore, HA-only coating could ensure corrosion resistance when Cu content does not exceed 4 wt.%. The results of biocompatibility tests of SSS on dogs showed that bone formation and biocompatibility were favorable when Cu content did not exceed 4 wt.%. The biocompatibility with bone was generally favorable in Ti/TiN/HA film coating and HA-only coating, while bone formation was somewhat faster for the HA film coated surface than for the Ti/TiN/HA film coating. Also, good cell growth and osseointegration without toxicity were observed.

Extravehicular Activity Asteroid Exploration and Sample Collection Capability

NASA Technical Reports Server (NTRS)

Sipila, Stephanie A.; Scoville, Zebulon C.; Bowie, Jonathan T.; Buffington, Jesse A.

2014-01-01

One of the challenging primary objectives associated with NASA's Asteroid Redirect Crewed Mission (ARCM) is to demonstrate deep space Extravehicular Activity (EVA) and tools and to obtain asteroid samples to return to Earth for further study. Prior Shuttle and International Space Station (ISS) spacewalks have benefited from engineered EVA interfaces which have been designed and manufactured on Earth. Rigid structurally mounted handrails, and tools with customized interfaces and restraints optimize EVA performance. For ARCM, EVA complexity increases due to the uncertainty of the asteroid properties. The variability of rock size, shape and composition, as well as behavior of the asteroid capture mechanism will complicate EVA translation, tool restraint, and body stabilization. The unknown asteroid hardness and brittleness will complicate tool use. The rock surface will introduce added safety concerns for cut gloves and debris control. Feasible solutions to meet ARCM EVA objectives were identified using experience gained during Apollo, Shuttle, and ISS EVAs, terrestrial mountaineering practices, NASA Extreme Environment Mission Operations (NEEMO) 16 mission, and during Neutral Buoyancy Laboratory testing in the Modified Advanced Crew Escape Suit (MACES) suit. This paper will summarize the overall operational concepts for conducting EVAs for the ARCM mission including translation paths and body restraint methods, potential tools used to extract the samples, design implications for the Asteroid Redirect Vehicle (ARV) for EVA, and the results of early development testing of potential EVA tasks.

Efficacy of brain-computer interface-driven neuromuscular electrical stimulation for chronic paresis after stroke.

PubMed

Mukaino, Masahiko; Ono, Takashi; Shindo, Keiichiro; Fujiwara, Toshiyuki; Ota, Tetsuo; Kimura, Akio; Liu, Meigen; Ushiba, Junichi

2014-04-01

Brain computer interface technology is of great interest to researchers as a potential therapeutic measure for people with severe neurological disorders. The aim of this study was to examine the efficacy of brain computer interface, by comparing conventional neuromuscular electrical stimulation and brain computer interface-driven neuromuscular electrical stimulation, using an A-B-A-B withdrawal single-subject design. A 38-year-old male with severe hemiplegia due to a putaminal haemorrhage participated in this study. The design involved 2 epochs. In epoch A, the patient attempted to open his fingers during the application of neuromuscular electrical stimulation, irrespective of his actual brain activity. In epoch B, neuromuscular electrical stimulation was applied only when a significant motor-related cortical potential was observed in the electroencephalogram. The subject initially showed diffuse functional magnetic resonance imaging activation and small electro-encephalogram responses while attempting finger movement. Epoch A was associated with few neurological or clinical signs of improvement. Epoch B, with a brain computer interface, was associated with marked lateralization of electroencephalogram (EEG) and blood oxygenation level dependent responses. Voluntary electromyogram (EMG) activity, with significant EEG-EMG coherence, was also prompted. Clinical improvement in upper-extremity function and muscle tone was observed. These results indicate that self-directed training with a brain computer interface may induce activity- dependent cortical plasticity and promote functional recovery. This preliminary clinical investigation encourages further research using a controlled design.

Enhancing CO2 Electroreduction with the Metal-Oxide Interface.

PubMed

Gao, Dunfeng; Zhang, Yi; Zhou, Zhiwen; Cai, Fan; Zhao, Xinfei; Huang, Wugen; Li, Yangsheng; Zhu, Junfa; Liu, Ping; Yang, Fan; Wang, Guoxiong; Bao, Xinhe

2017-04-26

The electrochemical CO 2 reduction reaction (CO 2 RR) typically uses transition metals as the catalysts. To improve the efficiency, tremendous efforts have been dedicated to tuning the morphology, size, and structure of metal catalysts and employing electrolytes that enhance the adsorption of CO 2 . We report here a strategy to enhance CO 2 RR by constructing the metal-oxide interface. We demonstrate that Au-CeO x shows much higher activity and Faradaic efficiency than Au or CeO x alone for CO 2 RR. In situ scanning tunneling microscopy and synchrotron-radiation photoemission spectroscopy show that the Au-CeO x interface is dominant in enhancing CO 2 adsorption and activation, which can be further promoted by the presence of hydroxyl groups. Density functional theory calculations indicate that the Au-CeO x interface is the active site for CO 2 activation and the reduction to CO, where the synergy between Au and CeO x promotes the stability of key carboxyl intermediate (*COOH) and thus facilitates CO 2 RR. Similar interface-enhanced CO 2 RR is further observed on Ag-CeO x , demonstrating the generality of the strategy for enhancing CO 2 RR.

Enhancing CO 2 electroreduction with the metal–oxide interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Dunfeng; Zhang, Yi; Zhou, Zhiwen

2017-04-09

Here, the electrochemical CO 2 reduction reaction (CO 2RR) typically uses transition metals as the catalysts. To improve the efficiency, tremendous efforts have been dedicated to tuning the morphology, size, and structure of metal catalysts and employing electrolytes that enhance the adsorption of CO 2. We report here a strategy to enhance CO 2RR by constructing the metal–oxide interface. We demonstrate that Au–CeO x shows much higher activity and Faradaic efficiency than Au or CeO x alone for CO 2RR. In situ scanning tunneling microscopy and synchrotron-radiation photoemission spectroscopy show that the Au–CeO x interface is dominant in enhancing COmore » 2 adsorption and activation, which can be further promoted by the presence of hydroxyl groups. Density functional theory calculations indicate that the Au–CeO x interface is the active site for CO 2 activation and the reduction to CO, where the synergy between Au and CeO x promotes the stability of key carboxyl intermediate (*COOH) and thus facilitates CO 2RR. Similar interface-enhanced CO 2RR is further observed on Ag–CeO x, demonstrating the generality of the strategy for enhancing CO 2RR.« less

Allosteric Inhibition of Bcr-Abl Kinase by High Affinity Monobody Inhibitors Directed to the Src Homology 2 (SH2)-Kinase Interface*

PubMed Central

Wojcik, John; Lamontanara, Allan Joaquim; Grabe, Grzegorz; Koide, Akiko; Akin, Louesa; Gerig, Barbara; Hantschel, Oliver; Koide, Shohei

2016-01-01

Bcr-Abl is a constitutively active kinase that causes chronic myelogenous leukemia. We have shown that a tandem fusion of two designed binding proteins, termed monobodies, directed to the interaction interface between the Src homology 2 (SH2) and kinase domains and to the phosphotyrosine-binding site of the SH2 domain, respectively, inhibits the Bcr-Abl kinase activity. Because the latter monobody inhibits processive phosphorylation by Bcr-Abl and the SH2-kinase interface is occluded in the active kinase, it remained undetermined whether targeting the SH2-kinase interface alone was sufficient for Bcr-Abl inhibition. To address this question, we generated new, higher affinity monobodies with single nanomolar KD values targeting the kinase-binding surface of SH2. Structural and mutagenesis studies revealed the molecular underpinnings of the monobody-SH2 interactions. Importantly, the new monobodies inhibited Bcr-Abl kinase activity in vitro and in cells, and they potently induced cell death in chronic myelogenous leukemia cell lines. This work provides strong evidence for the SH2-kinase interface as a pharmacologically tractable site for allosteric inhibition of Bcr-Abl. PMID:26912659

Experimental study of an isochorically heated heterogeneous interface. A progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez, Juan Carlos

2015-08-20

Outline of the presentation: Studying possible mix / interface motion between heterogeneous low/high Z interfaces driven by 2-fluid or kinetic plasma effects (Heated to few eV, Sharp (sub µm) interface); Isochoric heating to initialize interface done with Al quasimonoenergetic ion beams on Trident; Have measured isochoric heating in individual materials intended for compound targets; Fielded experiments on Trident to measure interface motion (Gold-diamond, tin-aluminium); Measured heated-sample temperature with streaked optical pyrometry (SOP) (UT Austin led (research contract), SOP tests → heating uniformity Vs thickness on Al foils. Results are being analyzed.

Immersed Boundary Simulations of Active Fluid Droplets

PubMed Central

Hawkins, Rhoda J.

2016-01-01

We present numerical simulations of active fluid droplets immersed in an external fluid in 2-dimensions using an Immersed Boundary method to simulate the fluid droplet interface as a Lagrangian mesh. We present results from two example systems, firstly an active isotropic fluid boundary consisting of particles that can bind and unbind from the interface and generate surface tension gradients through active contractility. Secondly, a droplet filled with an active polar fluid with homeotropic anchoring at the droplet interface. These two systems demonstrate spontaneous symmetry breaking and steady state dynamics resembling cell motility and division and show complex feedback mechanisms with minimal degrees of freedom. The simulations outlined here will be useful for quantifying the wide range of dynamics observable in these active systems and modelling the effects of confinement in a consistent and adaptable way. PMID:27606609

Software for Improved Extraction of Data From Tape Storage

NASA Technical Reports Server (NTRS)

Cheng, Chiu-Fu

2003-01-01

A computer program has been written to replace the original software of Racal Storeplex Delta tape recorders, which are used at Stennis Space Center. The original software could be activated by a command- line interface only; the present software offers the option of a command-line or graphical user interface. The present software also offers the option of batch-file operation (activation by a file that contains command lines for operations performed consecutively). The present software is also more reliable than was the original software: The original software was plagued by several deficiencies that made it difficult to execute, modify, and test. In addition, when using the original software to extract data that had been recorded within specified intervals of time, the resolution with which one could control starting and stopping times was no finer than about a second (or, in some cases, several seconds). In contrast, the present software is capable of controlling playback times to within 1/100 second of times specified by the user, assuming that the tape-recorder clock is accurate to within 1/100 second.

Software for Improved Extraction of Data From Tape Storage

NASA Technical Reports Server (NTRS)

Cheng, Chiu-Fu

2002-01-01

A computer program has been written to replace the original software of Racal Storeplex Delta tape recorders, which are still used at Stennis Space Center but have been discontinued by the manufacturer. Whereas the original software could be activated by a command-line interface only, the present software offers the option of a command-line or graphical user interface. The present software also offers the option of batch-file operation (activation by a file that contains command lines for operations performed consecutively). The present software is also more reliable than was the original software: The original software was plagued by several deficiencies that made it difficult to execute, modify, and test. In addition, when using the original software to extract data that had been recorded within specified intervals of time, the resolution with which one could control starting and stopping times was no finer than about a second (or, in some cases, several seconds). In contrast, the present software is capable of controlling playback times to within 1/100 second of times specified by the user, assuming that the tape-recorder clock is accurate to within 1/100 second.

A new JAVA interface implementation of THESIAS: testing haplotype effects in association studies.

PubMed

Tregouet, D A; Garelle, V

2007-04-15

THESIAS (Testing Haplotype EffectS In Association Studies) is a popular software for carrying haplotype association analysis in unrelated individuals. In addition to the command line interface, a graphical JAVA interface is now proposed allowing one to run THESIAS in a user-friendly manner. Besides, new functionalities have been added to THESIAS including the possibility to analyze polychotomous phenotype and X-linked polymorphisms. The software package including documentation and example data files is freely available at http://genecanvas.ecgene.net. The source codes are also available upon request.

Mechanical evaluation of a tissue-engineered zone of calcification in a bone–hydrogel osteochondral construct

PubMed Central

Hollenstein, Jérôme; Terrier, Alexandre; Cory, Esther; Chen, Albert C.; Sah, Robert L.; Pioletti, Dominique P.

2016-01-01

The objective of this study was to test the hypothesis that mechanical properties of artificial osteochondral constructs can be improved by a tissue-engineered zone of calcification (teZCC) at the bone–hydrogel interface. Experimental push-off tests were performed on osteochondral constructs with or without a teZCC. In parallel, a numerical model of the osteochondral defect treatment was developed and validated against experimental results. Experimental results showed that the shear strength at the bone–hydrogel interface increased by 100% with the teZCC. Numerical predictions of the osteochondral defect treatment showed that the shear stress at the bone–hydrogel interface was reduced with the teZCC. We conclude that a teZCC in osteochondral constructs can provide two improvements. First, it increases the strength of the bone–hydrogel interface and second, it reduces the stress at this interface. PMID:23706035

Testing of Environmental Satellite Bus-Instrument Interfaces Using Engineering Models

NASA Technical Reports Server (NTRS)

Gagnier, Donald; Hayner, Rick; Nosek, Thomas; Roza, Michael; Hendershot, James E.; Razzaghi, Andrea I.

2004-01-01

This paper discusses the formulation and execution of a laboratory test of the electrical interfaces between multiple atmospheric scientific instruments and the spacecraft bus that carries them. The testing, performed in 2002, used engineering models of the instruments and the Aura spacecraft bus electronics. Aura is one of NASA s Earth Observatory System missions. The test was designed to evaluate the complex interfaces in the command and data handling subsystems prior to integration of the complete flight instruments on the spacecraft. A problem discovered during the flight integration phase of the observatory can cause significant cost and schedule impacts. The tests successfully revealed problems and led to their resolution before the full-up integration phase, saving significant cost and schedule. This approach could be beneficial for future environmental satellite programs involving the integration of multiple, complex scientific instruments onto a spacecraft bus.

ESTL tracking and data relay satellite /TDRSS/ simulation system

NASA Technical Reports Server (NTRS)

Kapell, M. H.

1980-01-01

The Tracking Data Relay Satellite System (TDRSS) provides single access forward and return communication links with the Shuttle/Orbiter via S-band and Ku-band frequency bands. The ESTL (Electronic Systems Test Laboratory) at Lyndon B. Johnson Space Center (JSC) utilizes a TDRS satellite simulator and critical TDRS ground hardware for test operations. To accomplish Orbiter/TDRSS relay communications performance testing in the ESTL, a satellite simulator was developed which met the specification requirements of the TDRSS channels utilized by the Orbiter. Actual TDRSS ground hardware unique to the Orbiter communication interfaces was procured from individual vendors, integrated in the ESTL, and interfaced via a data bus for control and status monitoring. This paper discusses the satellite simulation hardware in terms of early development and subsequent modifications. The TDRS ground hardware configuration and the complex computer interface requirements are reviewed. Also, special test hardware such as a radio frequency interference test generator is discussed.

Overview of CEV Thermal Protection System Seal Development

NASA Technical Reports Server (NTRS)

DeMange, Jeff; Taylor, Shawn; Dunlap, Patrick; Steinetz, Bruce; Delgado, Irebert; Finkbeiner, Josh; Mayer, John

2009-01-01

NASA GRC supporting design, development, and implementation of numerous seal systems for the Orion CEV: a) HS-to-BS interface. b) Compression pad. HS-to-BS Interface Seal System: a) design has evolved as a result of changes with the CEV TPS. b) Seal system is currently under development/evaluation. Coupon level tests, Arc jet tests, and Validation test development. Compression Pad: a) Finalizing design options. b) Evaluating material candidates.

Evaluation of an Intelligent Tutoring System in Pathology: Effects of External Representation on Performance Gains, Metacognition, and Acceptance

PubMed Central

Crowley, Rebecca S.; Legowski, Elizabeth; Medvedeva, Olga; Tseytlin, Eugene; Roh, Ellen; Jukic, Drazen

2007-01-01

Objective Determine effects of computer-based tutoring on diagnostic performance gains, meta-cognition, and acceptance using two different problem representations. Describe impact of tutoring on spectrum of diagnostic skills required for task performance. Identify key features of student-tutor interaction contributing to learning gains. Design Prospective, between-subjects study, controlled for participant level of training. Resident physicians in two academic pathology programs spent four hours using one of two interfaces which differed mainly in external problem representation. The case-focused representation provided an open-learning environment in which students were free to explore evidence-hypothesis relationships within a case, but could not visualize the entire diagnostic space. The knowledge-focused representation provided an interactive representation of the entire diagnostic space, which more tightly constrained student actions. Measurements Metrics included results of pretest, post-test and retention-test for multiple choice and case diagnosis tests, ratios of performance to student reported certainty, results of participant survey, learning curves, and interaction behaviors during tutoring. Results Students had highly significant learning gains after one tutoring session. Learning was retained at one week. There were no differences between the two interfaces in learning gains on post-test or retention test. Only students in the knowledge-focused interface exhibited significant metacognitive gains from pretest to post-test and pretest to retention test. Students rated the knowledge-focused interface significantly higher than the case-focused interface. Conclusions Cognitive tutoring is associated with improved diagnostic performance in a complex medical domain. The effect is retained at one-week post-training. Knowledge-focused external problem representation shows an advantage over case-focused representation for metacognitive effects and user acceptance. PMID:17213494

Evaluation of an intelligent tutoring system in pathology: effects of external representation on performance gains, metacognition, and acceptance.

PubMed

Crowley, Rebecca S; Legowski, Elizabeth; Medvedeva, Olga; Tseytlin, Eugene; Roh, Ellen; Jukic, Drazen

2007-01-01

Determine effects of computer-based tutoring on diagnostic performance gains, meta-cognition, and acceptance using two different problem representations. Describe impact of tutoring on spectrum of diagnostic skills required for task performance. Identify key features of student-tutor interaction contributing to learning gains. Prospective, between-subjects study, controlled for participant level of training. Resident physicians in two academic pathology programs spent four hours using one of two interfaces which differed mainly in external problem representation. The case-focused representation provided an open-learning environment in which students were free to explore evidence-hypothesis relationships within a case, but could not visualize the entire diagnostic space. The knowledge-focused representation provided an interactive representation of the entire diagnostic space, which more tightly constrained student actions. Metrics included results of pretest, post-test and retention-test for multiple choice and case diagnosis tests, ratios of performance to student reported certainty, results of participant survey, learning curves, and interaction behaviors during tutoring. Students had highly significant learning gains after one tutoring session. Learning was retained at one week. There were no differences between the two interfaces in learning gains on post-test or retention test. Only students in the knowledge-focused interface exhibited significant metacognitive gains from pretest to post-test and pretest to retention test. Students rated the knowledge-focused interface significantly higher than the case-focused interface. Cognitive tutoring is associated with improved diagnostic performance in a complex medical domain. The effect is retained at one-week post-training. Knowledge-focused external problem representation shows an advantage over case-focused representation for metacognitive effects and user acceptance.

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.2354 - What performance tests, design evaluations, and performance evaluations must I conduct?

Code of Federal Regulations, 2011 CFR

2011-07-01

... of Gaseous Organic Compounds by Direct Interface Gas Chromatography-Mass Spectrometry (incorporated... Method for Determination of Gaseous Organic Compounds by Direct Interface Gas Chromatography-Mass... Interface Gas Chromatography-Mass Spectrometry (incorporated by reference, see § 63.14),; or (B) For target...

Interface Architecture for Testing in Foreign Language Education

ERIC Educational Resources Information Center

Laborda, Jesus Garcia

2009-01-01

The implications of new learning environments have been far-reaching and pervasive (Plass, 1998), at least in the field of interface design both in traditional computer and mobile devices (Fallahkhair, Pemberton, & Griffiths, 2007). Given the current status of efficient models, educators need the unproven unification of interfaces and working…

Design and implementation of an inter-agency, multi-mission space flight operations network interface

NASA Technical Reports Server (NTRS)

Byrne, R.; Scharf, M.; Doan, D.; Liu, J.; Willems, A.

2004-01-01

An advanced network interface was designed and implemented by a team from the Jet Propulsion Lab with support from the European Space Operations Center. This poster shows the requirements for the interface, the design, the topology, the testing and lessons learned from the whole implementation.

A Graphical Database Interface for Casual, Naive Users.

ERIC Educational Resources Information Center

Burgess, Clifford; Swigger, Kathleen

1986-01-01

Describes the design of a database interface for infrequent users of computers which consists of a graphical display of a model of a database and a natural language query language. This interface was designed for and tested with physicians at the University of Texas Health Science Center in Dallas. (LRW)

Portable Life Support System: PLSS 101

NASA Technical Reports Server (NTRS)

Thomas, Gretchen A.

2011-01-01

This presentation reviewed basic interfaces and considerations necessary for prototype suit hardware integration from an advanced spacesuit engineer perspective during the early design and test phases. The discussion included such topics such as the human interface, suit pass-throughs, keep-out zones, hardware form factors, subjective feedback from suit tests, and electricity in the suit.

U.S. Exploration EVA: ConOps, Interfaces and Test Objectives for Airlocks

NASA Technical Reports Server (NTRS)

Buffington, J.

2017-01-01

NASA is moving forward on defining the xEVA System Architecture and its implications to the spacecraft that host exploration EVA systems. This presentation provides an overview of the latest information for NASA's Concept of Operations (ConOps), Interfaces and corresponding Test Objectives for Airlocks hosting the xEVA System.

Unified Framework for Development, Deployment and Robust Testing of Neuroimaging Algorithms

PubMed Central

Joshi, Alark; Scheinost, Dustin; Okuda, Hirohito; Belhachemi, Dominique; Murphy, Isabella; Staib, Lawrence H.; Papademetris, Xenophon

2011-01-01

Developing both graphical and command-line user interfaces for neuroimaging algorithms requires considerable effort. Neuroimaging algorithms can meet their potential only if they can be easily and frequently used by their intended users. Deployment of a large suite of such algorithms on multiple platforms requires consistency of user interface controls, consistent results across various platforms and thorough testing. We present the design and implementation of a novel object-oriented framework that allows for rapid development of complex image analysis algorithms with many reusable components and the ability to easily add graphical user interface controls. Our framework also allows for simplified yet robust nightly testing of the algorithms to ensure stability and cross platform interoperability. All of the functionality is encapsulated into a software object requiring no separate source code for user interfaces, testing or deployment. This formulation makes our framework ideal for developing novel, stable and easy-to-use algorithms for medical image analysis and computer assisted interventions. The framework has been both deployed at Yale and released for public use in the open source multi-platform image analysis software—BioImage Suite (bioimagesuite.org). PMID:21249532

Remote Advanced Payload Test Rig (RAPTR) Portable Payload Test System for the International Space Station

NASA Technical Reports Server (NTRS)

De La Cruz, Melinda; Henderson, Steve

2016-01-01

The RAPTR was developed to test ISS payloads for NASA. RAPTR is a simulation of the Command and Data Handling (C&DH) interfaces of the ISS (MIL-STD1553B, Ethernet and TAXI) and is designed for rapid testing and deployment of payload experiments to the ISS. The ISS's goal is to reduce the amount of time it takes for a payload developer to build, test and fly a payload, including payload software. The RAPTR meets this need with its user oriented, visually rich interface.

Advanced flight control system study

NASA Technical Reports Server (NTRS)

Hartmann, G. L.; Wall, J. E., Jr.; Rang, E. R.; Lee, H. P.; Schulte, R. W.; Ng, W. K.

1982-01-01

A fly by wire flight control system architecture designed for high reliability includes spare sensor and computer elements to permit safe dispatch with failed elements, thereby reducing unscheduled maintenance. A methodology capable of demonstrating that the architecture does achieve the predicted performance characteristics consists of a hierarchy of activities ranging from analytical calculations of system reliability and formal methods of software verification to iron bird testing followed by flight evaluation. Interfacing this architecture to the Lockheed S-3A aircraft for flight test is discussed. This testbed vehicle can be expanded to support flight experiments in advanced aerodynamics, electromechanical actuators, secondary power systems, flight management, new displays, and air traffic control concepts.

Exoskeleton for gait rehabilitation of children: Conceptual design.

PubMed

Cornejo, Jorge L; Santana, Jesus F; Salinas, Sergio A

2017-07-01

This paper presents the conceptual design of an exoskeleton for gait rehabilitation of children. This system has electronics, mechanicals and software sections, which are implemented and tested using a mannequin of a child. The prototype uses servomotors to move robotic joints that are attached to simulated patient's legs. The design has 4 DOF (degrees of freedom) two for hip joints and other two for knee joints, in the sagittal plane. A microcontroller measures sensor signals, controls motors and exchanges data with a computer. The user interacts with a graphical interface to configure, control and monitor the exoskeleton activities. The laboratory tests show soften movements in joint angle tracking.

Research and technology annual report, FY 1990

NASA Technical Reports Server (NTRS)

1990-01-01

Given here is the annual report of the John C. Stennis Space Center (SSC), a NASA center responsible for testing NASA's large propulsion systems, developing supporting test technologies, conducting research in a variety of earth science disciplines, and facilitating the commercial uses of NASA-developed technologies. Described here are activities of the Earth Sciences Research Program, the Technology Development Program, commercial programs, the Technology Utilization Program, and the Information Systems Program. Work is described in such areas as forest ecosystems, land-sea interface, wetland biochemical flux, thermal imaging of crops, gas detectors, plume analysis, synthetic aperture radar, forest resource management, applications engineering, and the Earth Observations Commercial Applications Program.

Workshop AccessibleTV "Accessible User Interfaces for Future TV Applications"

NASA Astrophysics Data System (ADS)

Hahn, Volker; Hamisu, Pascal; Jung, Christopher; Heinrich, Gregor; Duarte, Carlos; Langdon, Pat

Approximately half of the elderly people over 55 suffer from some type of typically mild visual, auditory, motor or cognitive impairment. For them interaction, especially with PCs and other complex devices is sometimes challenging, although accessible ICT applications could make much of a difference for their living quality. Basically they have the potential to enable or simplify participation and inclusion in their surrounding private and professional communities. However, the availability of accessible user interfaces being capable to adapt to the specific needs and requirements of users with individual impairments is very limited. Although there are a number of APIs [1, 2, 3, 4] available for various platforms that allow developers to provide accessibility features within their applications, today none of them provides features for the automatic adaptation of multimodal interfaces being capable to automatically fit the individual requirements of users with different kinds of impairments. Moreover, the provision of accessible user interfaces is still expensive and risky for application developers, as they need special experience and effort for user tests. Today many implementations simply neglect the needs of elderly people, thus locking out a large portion of their potential users. The workshop is organized as part of the dissemination activity for the European-funded project GUIDE "Gentle user interfaces for elderly people", which aims to address this situation with a comprehensive approach for the realization of multimodal user interfaces being capable to adapt to the needs of users with different kinds of mild impairments. As application platform, GUIDE will mainly target TVs and Set-Top Boxes, such as the emerging Connected-TV or WebTV platforms, as they have the potential to address the needs of the elderly users with applications such as for home automation, communication or continuing education.

Gemini 8.2-m primary mirror no. 1 polishing

NASA Astrophysics Data System (ADS)

Cayrel, Marc; Beraud, P.; Paseri, Jacques; Dromas, E.

1998-08-01

The 8-m class primary mirrors of the GEMINI Telescopes are thin ULE menisci actively supported. The two mirror blanks are produced by CORNING, the optical figuring, manufacturing and assembling of interfaces are done by REOSC. REOSC is as well in charge of the transportation of the mirror blanks from CORNING to REOSC, and of the shipment of the finished optics to Hawaii and to Chile. The mirror assembly requirements are summarized, the manufacturing and testing methods are addressed. REOSC had to design and manufacture a dedicated active supporting system, representative of the one used at the telescope level. Its design and performance are presented. The manufacturing steps undertaken at REOSC and the results achieved are then detailed: mirror blank surface generating and grinding, polishing, testing. The current status of the mirrors is finally presented.

Gluing interface qualification test results and gluing process development of the EUCLID near-infrared spectro-photometer optical assembly

NASA Astrophysics Data System (ADS)

Mottaghibonab, A.; Thiele, H.; Gubbini, E.; Dubowy, M.; Gal, C.; Mecsaci, A.; Gawlik, K.; Vongehr, M.; Grupp, F.; Penka, D.; Wimmer, C.; Bender, R.

2016-07-01

The Near Infrared Spectro-Photometer Optical assembly (NIOA) of EUCLID satellite requires high precision large lens holders with different lens materials, shapes and diameters. The aspherical lenses are glued into their separate CTE matched lens holder. The gluing of the lenses in their holder with 2K epoxy is selected as bonding process to minimize the stress in the lenses to achieve the required surface form error (SFE) performance (32nm) and lens position stability (+/-10μm) due to glue shrinkage. Adhesive shrinkage stress occurs during the glue curing at room temperature and operation in cryogenic temperatures, which might overstress the lens, cause performance loss, lens breakage or failure of the gluing interface. The selection of the suitable glue and required bonding parameters, design and qualification of the gluing interface, development and verification of the gluing process was a great challenge because of the low TRL and heritage of the bonding technology. The different material combinations (CaF2 to SS316L, LF5G15 and S-FTM16 to Titanium, SUPRASIL3001 to Invar M93), large diameter (168mm) and thin edge of the lenses, cryogenic nonoperational temperature (100K) and high performance accuracy of the lenses were the main design driver of the development. The different coefficients of thermal expansion (CTE) between lens and lens holder produce large local mechanical stress. As hygroscopic crystal calcium fluoride (CaF2) is very sensitive to moisture therefore an additional surface treatment of the gluing area is necessary. Extensive tests e.g glue handling and single lap shear tests are performed to select the suitable adhesive. Interface connection tests are performed to verify the feasibility of selected design (double pad design), injection channel, the roughness and treatment of the metal and lens interfaces, glue thickness, glue pad diameter and the gluing process. CTE and dynamic measurements of the glue, thermal cycling, damp- heat, connection shear and tension tests with all material combinations at RT and 100K are carried out to qualify the gluing interface. The gluing interface of the glued lenses in their mounts is also qualified with thermal cycling, 3D coordinate measurements before and after environmental tests, Polarimetry and vibration test of the lens assemblies. A multi-function double pad gluing tool and lens mounting tool is designed, manufactured and verified to meet the lens positioning and alignment performance of the lens in the holder which provides the possibility to glue lenses, filters, mirrors with different diameters, shapes and thickness with +/-10μm accuracy in plane, out of plane and +/-10 arcsec in tip/tilt with respect to the lens holder interface. The paper presents the glue interface qualification results, the qualification/verification methods, the developed ground support equipment and the gluing process of the EUCLID high precision large cryogenic lens mounts. Test results achieved in the test campaign demonstrate the suitability of the selected adhesive, glue pad design, interface parameters and the processes for the precise gluing of the lenses in lens holders for all lenses. The qualification models of the NIOA are successfully glued and qualified. The developed process can also be used for other glass materials e.g. MaF2 and optical black coated metallic surfaces.

In vitro toxicity testing of cigarette smoke based on the air-liquid interface exposure: A review.

PubMed

Li, Xiang

2016-10-01

Cigarette smoke is a complex aerosol comprising particulate phase and gaseous vapour phase. The air-liquid interface exposure provides a possible technical means to implement whole smoke exposure for the assessment of tobacco products. In this review, the research progress in the in vitro toxicity testing of cigarette smoke based on the air-liquid interface exposure is summarized. The contents presented involve mainly cytotoxicity, genotoxicity, oxidative stress, inflammation, systems toxicology, 3D culture and cigarette smoke dosimetry related to cigarette smoke, as well as the assessment of electronic cigarette aerosol. Prospect of the application of the air-liquid interface exposure method in assessing the biological effects of tobacco smoke is discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Performance Evaluation of Speech Recognition Systems as a Next-Generation Pilot-Vehicle Interface Technology

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Shelton, Kevin J.; Prinzel, Lawrence J., III; Bailey, Randall E.

2016-01-01

During the flight trials known as Gulfstream-V Synthetic Vision Systems Integrated Technology Evaluation (GV-SITE), a Speech Recognition System (SRS) was used by the evaluation pilots. The SRS system was intended to be an intuitive interface for display control (rather than knobs, buttons, etc.). This paper describes the performance of the current "state of the art" Speech Recognition System (SRS). The commercially available technology was evaluated as an application for possible inclusion in commercial aircraft flight decks as a crew-to-vehicle interface. Specifically, the technology is to be used as an interface from aircrew to the onboard displays, controls, and flight management tasks. A flight test of a SRS as well as a laboratory test was conducted.

Intelligent interface design and evaluation

NASA Technical Reports Server (NTRS)

Greitzer, Frank L.

1988-01-01

Intelligent interface concepts and systematic approaches to assessing their functionality are discussed. Four general features of intelligent interfaces are described: interaction efficiency, subtask automation, context sensitivity, and use of an appropriate design metaphor. Three evaluation methods are discussed: Functional Analysis, Part-Task Evaluation, and Operational Testing. Design and evaluation concepts are illustrated with examples from a prototype expert system interface for environmental control and life support systems for manned space platforms.

Interface evaluation for soft robotic manipulators

NASA Astrophysics Data System (ADS)

Moore, Kristin S.; Rodes, William M.; Csencsits, Matthew A.; Kwoka, Martha J.; Gomer, Joshua A.; Pagano, Christopher C.

2006-05-01

The results of two usability experiments evaluating an interface for the operation of OctArm, a biologically inspired robotic arm modeled after an octopus tentacle, are reported. Due to the many degrees-of-freedom (DOF) for the operator to control, such 'continuum' robotic limbs provide unique challenges for human operators because they do not map intuitively. Two modes have been developed to control the arm and reduce the DOF under the explicit direction of the operator. In coupled velocity (CV) mode, a joystick controls changes in arm curvature. In end-effector (EE) mode, a joystick controls the arm by moving the position of an endpoint along a straight line. In Experiment 1, participants used the two modes to grasp objects placed at different locations in a virtual reality modeling language (VRML). Objective measures of performance and subjective preferences were recorded. Results revealed lower grasp times and a subjective preference for the CV mode. Recommendations for improving the interface included providing additional feedback and implementation of an error recovery function. In Experiment 2, only the CV mode was tested with improved training of participants and several changes to the interface. The error recovery function was implemented, allowing participants to reverse through previously attained positions. The mean time to complete the trials in the second usability test was reduced by more than 4 minutes compared with the first usability test, confirming the interface changes improved performance. The results of these tests will be incorporated into future versions of the arm and improve future usability tests.

An Airbus arrives at KSC with third MPLM

NASA Technical Reports Server (NTRS)

2001-01-01

An Airbus '''Beluga''' air cargo plane, The Super Transporter, taxis onto the parking apron at KSC's Shuttle Landing Facility. Its cargo, from the factory of Alenia Aerospazio in Turin, Italy, is the Italian Space Agency's Multi-Purpose Logistics Module Donatello, the third of three for the International Space Station. The module will be transported to the Space Station Processing Facility for processing. Among the activities for the payload test team are integrated electrical tests with other Station elements in the SSPF, leak tests, electrical and software compatibility tests with the Space Shuttle (using the Cargo Integrated Test equipment) and an Interface Verification Test once the module is installed in the Space Shuttle's payload bay at the launch pad. The most significant mechanical task to be performed on Donatello in the SSPF is the installation and outfitting of the racks for carrying the various experiments and cargo.

MPLM Donatello is offloaded at the SLF

NASA Technical Reports Server (NTRS)

2001-01-01

At the Shuttle Landing Facility, workers in cherry pickers (right) help guide offloading of the Italian Space Agency's Multi-Purpose Logistics Module Donatello from the Airbus '''Beluga''' air cargo plane that brought it from the factory of Alenia Aerospazio in Turin, Italy. The third of three for the International Space Station, the module will be transported to the Space Station Processing Facility for processing. Among the activities for the payload test team are integrated electrical tests with other Station elements in the SSPF, leak tests, electrical and software compatibility tests with the Space Shuttle (using the Cargo Integrated Test equipment) and an Interface Verification Test once the module is installed in the Space Shuttle's payload bay at the launch pad. The most significant mechanical task to be performed on Donatello in the SSPF is the installation and outfitting of the racks for carrying the various experiments and cargo.

KSC01pp0234

NASA Image and Video Library

2001-02-01

An Airbus “Beluga” air cargo plane, The Super Transporter, taxis onto the parking apron at KSC’s Shuttle Landing Facility. Its cargo, from the factory of Alenia Aerospazio in Turin, Italy, is the Italian Space Agency’s Multi-Purpose Logistics Module Donatello, the third of three for the International Space Station. The module will be transported to the Space Station Processing Facility for processing. Among the activities for the payload test team are integrated electrical tests with other Station elements in the SSPF, leak tests, electrical and software compatibility tests with the Space Shuttle (using the Cargo Integrated Test equipment) and an Interface Verification Test once the module is installed in the Space Shuttle’s payload bay at the launch pad. The most significant mechanical task to be performed on Donatello in the SSPF is the installation and outfitting of the racks for carrying the various experiments and cargo

Targeting the SH2-Kinase Interface in Bcr-Abl Inhibits Leukemogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grebien, Florian; Hantschel, Oliver; Wojcik, John

2012-10-25

Chronic myelogenous leukemia (CML) is caused by the constitutively active tyrosine kinase Bcr-Abl and treated with the tyrosine kinase inhibitor (TKI) imatinib. However, emerging TKI resistance prevents complete cure. Therefore, alternative strategies targeting regulatory modules of Bcr-Abl in addition to the kinase active site are strongly desirable. Here, we show that an intramolecular interaction between the SH2 and kinase domains in Bcr-Abl is both necessary and sufficient for high catalytic activity of the enzyme. Disruption of this interface led to inhibition of downstream events critical for CML signaling and, importantly, completely abolished leukemia formation in mice. Furthermore, disruption of themore » SH2-kinase interface increased sensitivity of imatinib-resistant Bcr-Abl mutants to TKI inhibition. An engineered Abl SH2-binding fibronectin type III monobody inhibited Bcr-Abl kinase activity both in vitro and in primary CML cells, where it induced apoptosis. This work validates the SH2-kinase interface as an allosteric target for therapeutic intervention.« less

Targeting the SH2-kinase interface in Bcr-Abl inhibits leukemogenesis.

PubMed

Grebien, Florian; Hantschel, Oliver; Wojcik, John; Kaupe, Ines; Kovacic, Boris; Wyrzucki, Arkadiusz M; Gish, Gerald D; Cerny-Reiterer, Sabine; Koide, Akiko; Beug, Hartmut; Pawson, Tony; Valent, Peter; Koide, Shohei; Superti-Furga, Giulio

2011-10-14

Chronic myelogenous leukemia (CML) is caused by the constitutively active tyrosine kinase Bcr-Abl and treated with the tyrosine kinase inhibitor (TKI) imatinib. However, emerging TKI resistance prevents complete cure. Therefore, alternative strategies targeting regulatory modules of Bcr-Abl in addition to the kinase active site are strongly desirable. Here, we show that an intramolecular interaction between the SH2 and kinase domains in Bcr-Abl is both necessary and sufficient for high catalytic activity of the enzyme. Disruption of this interface led to inhibition of downstream events critical for CML signaling and, importantly, completely abolished leukemia formation in mice. Furthermore, disruption of the SH2-kinase interface increased sensitivity of imatinib-resistant Bcr-Abl mutants to TKI inhibition. An engineered Abl SH2-binding fibronectin type III monobody inhibited Bcr-Abl kinase activity both in vitro and in primary CML cells, where it induced apoptosis. This work validates the SH2-kinase interface as an allosteric target for therapeutic intervention. Copyright © 2011 Elsevier Inc. All rights reserved.

Targeting the SH2-Kinase Interface in Bcr-Abl Inhibits Leukemogenesis

PubMed Central

Grebien, Florian; Hantschel, Oliver; Wojcik, John; Kaupe, Ines; Kovacic, Boris; Wyrzucki, Arkadiusz M.; Gish, Gerald D.; Cerny-Reiterer, Sabine; Koide, Akiko; Beug, Hartmut; Pawson, Tony; Valent, Peter; Koide, Shohei; Superti-Furga, Giulio

2011-01-01

Summary Chronic myelogenous leukemia (CML) is caused by the constitutively active tyrosine kinase Bcr-Abl and treated with the tyrosine kinase inhibitor (TKI) imatinib. However, emerging TKI resistance prevents complete cure. Therefore, alternative strategies targeting regulatory modules of Bcr-Abl in addition to the kinase active site are strongly desirable. Here, we show that an intramolecular interaction between the SH2 and kinase domains in Bcr-Abl is both necessary and sufficient for high catalytic activity of the enzyme. Disruption of this interface led to inhibition of downstream events critical for CML signaling and, importantly, completely abolished leukemia formation in mice. Furthermore, disruption of the SH2-kinase interface increased sensitivity of imatinib-resistant Bcr-Abl mutants to TKI inhibition. An engineered Abl SH2-binding fibronectin type III monobody inhibited Bcr-Abl kinase activity both in vitro and in primary CML cells, where it induced apoptosis. This work validates the SH2-kinase interface as an allosteric target for therapeutic intervention. PaperFlick PMID:22000011

Microfluidic on-chip fluorescence-activated interface control system

PubMed Central

Haiwang, Li; Nguyen, N. T.; Wong, T. N.; Ng, S. L.

2010-01-01

A microfluidic dynamic fluorescence-activated interface control system was developed for lab-on-a-chip applications. The system consists of a straight rectangular microchannel, a fluorescence excitation source, a detection sensor, a signal conversion circuit, and a high-voltage feedback system. Aqueous NaCl as conducting fluid and aqueous glycerol as nonconducting fluid were introduced to flow side by side into the straight rectangular microchannel. Fluorescent dye was added to the aqueous NaCl to work as a signal representing the interface position. Automatic control of the liquid interface was achieved by controlling the electroosmotic effect that exists only in the conducting fluid using a high-voltage feedback system. A LABVIEW program was developed to control the output of high-voltage power supply according the actual interface position, and then the interface position is modified as the output of high-voltage power supply. At last, the interface can be moved to the desired position automatically using this feedback system. The results show that the system presented in this paper can control an arbitrary interface location in real time. The effects of viscosity ratio, flow rates, and polarity of electric field were discussed. This technique can be extended to switch the sample flow and droplets automatically. PMID:21173886

The electrochemistry of "solid/water" interfaces involved in PEM-H2O reactors: part I. The "Pt/water" interfaces.

PubMed

Wang, Qiang; Cha, Chuan-Sin; Lu, Juntao; Zhuang, Lin

2009-01-28

The nature and properties of Pt surfaces in contact with pure water in PEM-H2O reactors were mimetically studied by employing CV measurements with microelectrode techniques. These "Pt/water" interfaces were found to be electrochemically polarizable, and the local interfacial potential relative to reversible hydrogen electrode (RHE) potential in pure water is numerically the same as the potential value measured against a RHE in contact with PEM as the reference electrode. However, the structural parameters of the electric double layer at the "Pt/water" interfaces can be quite different from those at the "Pt/PEM" interfaces, and the kinetics of electrode processes could be seriously affected by the structure of electric double layer in pure water media. Besides, there is active diffusional flow of intermediates of electrode reactions between the "Pt/water" and the "Pt/PEM" interfaces, thus facilitating the active involvement of the "Pt/water" interfaces in the current-generation mechanism of PEM fuel cells and other types of PEM-H2O reactors.

Orbital operations study. Volume 2: Interfacing activities analysis. Part 4: Support operations activity group

NASA Technical Reports Server (NTRS)

Steinwachs, W. L.; Patrick, J. W.; Galvin, D. M.; Turkel, S. H.

1972-01-01

The findings of the support operations activity group of the orbital operations study are presented. Element interfaces, alternate approaches, design concepts, operational procedures, functional requirements, design influences, and approach selection are presented. The following areas are considered: (1) crew transfer, (2) cargo transfer, (3) propellant transfer, (4) attached element operations, and (5) attached element transport.

KSC-00pp1771

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- Lowered into the payload bay of the orbiter Atlantis, some of the STS-98 crew (center of the photo) look over part of the payload. From left are Mission Specialists Robert Curbeam, Tom Jones and Marsha Ivins. They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1761

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, the STS-98 crew talks with United Space Alliance worker Larry Oshein (right). Standing left to right are Mission Specialist Robert Curbeam, Commander Ken Cockrell, Mission Specialist Tom Jones, and Mission Specialists Mark Polansky and Marsha Ivins. The crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC-00pp1761

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, the STS-98 crew talks with United Space Alliance worker Larry Oshein (right). Standing left to right are Mission Specialist Robert Curbeam, Commander Ken Cockrell, Mission Specialist Tom Jones, and Mission Specialists Mark Polansky and Marsha Ivins. The crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1771

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- Lowered into the payload bay of the orbiter Atlantis, some of the STS-98 crew (center of the photo) look over part of the payload. From left are Mission Specialists Robert Curbeam, Tom Jones and Marsha Ivins. They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC00pp1770

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- Lowered into the payload bay of the orbiter Atlantis, some of the STS-98 crew look over part of the payload. At center is Mission Specialist Robert Curbeam; at right are Mission Specialists Marsha Ivins (standing) and Tom Jones (kneeling). They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

KSC-00pp1770

NASA Image and Video Library

2000-11-18

KENNEDY SPACE CENTER, FLA. -- Lowered into the payload bay of the orbiter Atlantis, some of the STS-98 crew look over part of the payload. At center is Mission Specialist Robert Curbeam; at right are Mission Specialists Marsha Ivins (standing) and Tom Jones (kneeling). They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated

A study of space-rated connectors using a robot end-effector

NASA Technical Reports Server (NTRS)

Nguyen, Charles C.

1995-01-01

The main research activities have been directed toward the study of the Robot Operated Materials Processing System (ROMPS), developed at GSFC under a flight project to investigate commercially promising in-space material processes and to design reflyable robot automated systems to be used in the above processes for low-cost operations. The research activities can be divided into two phases. Phase 1 dealt with testing of ROMPS robot mechanical interfaces and compliant device using a Stewart Platform testbed and Phase 2 with computer simulation study of the ROMPS robot control system. This report provides a summary of the results obtained in Phase 1 and Phase 2.

Acquisition and production of skilled behavior in dynamic decision-making tasks

NASA Technical Reports Server (NTRS)

Kirlik, Alex

1992-01-01

Detailed summaries of two NASA-funded research projects are provided. The first project was an ecological task analysis of the Star Cruiser model. Star Cruiser is a psychological model designed to test a subject's level of cognitive activity. Ecological task analysis is used as a framework to predict the types of cognitive activity required to achieve productive behavior and to suggest how interfaces can be manipulated to alleviate certain types of cognitive demands. The second project is presented in the form of a thesis for the Masters Degree. The thesis discusses the modeling of decision-making through the use of neural network and genetic-algorithm machine learning technologies.

The Development of a Dynamic Geomagnetic Cutoff Rigidity Model for the International Space Station

NASA Technical Reports Server (NTRS)

Smart, D. F.; Shea, M. A.

1999-01-01

We have developed a computer model of geomagnetic vertical cutoffs applicable to the orbit of the International Space Station. This model accounts for the change in geomagnetic cutoff rigidity as a function of geomagnetic activity level. This model was delivered to NASA Johnson Space Center in July 1999 and tested on the Space Radiation Analysis Group DEC-Alpha computer system to ensure that it will properly interface with other software currently used at NASA JSC. The software was designed for ease of being upgraded as other improved models of geomagnetic cutoff as a function of magnetic activity are developed.

KSC-07pd2616

NASA Image and Video Library

2007-09-28

KENNEDY SPACE CENTER, FLA. -- In the Orbiter Processing Facility, STS-122 crew members are introduced to part of the LESS. From left are Mission Specialists Hans Schlegel, Rex Walheim and European Space Agency astronaut Leopold Eyharts, Commander Stephen Frick, Mission Specialist Leland Melvin and Pilot Alan Poindexter. The crew is at Kennedy to take part in a crew equipment interface test, or CEIT, which helps familiarize them with equipment and payloads for the mission. Among the activities standard to a CEIT are harness training, inspection of the thermal protection system and camera operation for planned extravehicular activities, or EVAs. STS-122 is targeted for launch in December. Photo credit: NASA/Kim Shiflett

Fracture toughness of titanium-cement interfaces: effects of fibers and loading angles.

PubMed

Khandaker, Morshed; Utsaha, Khatri Chhetri; Morris, Tracy

2014-01-01

Ideal implant-cement or implant-bone interfaces are required for implant fixation and the filling of tissue defects created by disease. Micron- to nanosize osseointegrated features, such as surface roughness, fibers, porosity, and particles, have been fused with implants for improving the osseointegration of an implant with the host tissue in orthopedics and dentistry. The effects of fibers and loading angles on the interface fracture toughness of implant-cement specimens with and without fibers at the interface are not yet known. Such studies are important for the design of a long-lasting implant for orthopedic applications. The goal of this study was to improve the fracture toughness of an implant-cement interface by deposition of micron- to nanosize fibers on an implant surface. There were two objectives in the study: 1) to evaluate the influence of fibers on the fracture toughness of implant-cement interfaces with and without fibers at the interfaces, and 2) to evaluate the influence of loading angles on implant-cement interfaces with and without fibers at the interfaces. This study used titanium as the implant, poly(methyl methacrylate) (PMMA) as cement, and polycaprolactone (PCL) as fiber materials. An electrospinning unit was fabricated for the deposition of PCL unidirectional fibers on titanium (Ti) plates. The Evex tensile test stage was used to determine the interface fracture toughness (KC) of Ti-PMMA with and without PCL fibers at 0°, 45°, and 90° loading angles, referred to in this article as tension, mixed, and shear tests. The study did not find any significant interaction between fiber and loading angles (P>0.05), although there was a significant difference in the KC means of Ti-PMMA samples for the loading angles (P<0.05). The study also found a significant difference in the KC means of Ti-PMMA samples with and without fibers (P<0.05). The results showed that the addition of the micron- to nanosize PCL fibers on Ti improved the quality of the Ti-PMMA union. The results of the study are essential for fatigue testing and finite-element analysis of implant-cement interfaces to evaluate the performance of orthopedic and orthodontic implants.

Fracture toughness of titanium–cement interfaces: effects of fibers and loading angles

PubMed Central

Khandaker, Morshed; Utsaha, Khatri Chhetri; Morris, Tracy

2014-01-01

Ideal implant–cement or implant–bone interfaces are required for implant fixation and the filling of tissue defects created by disease. Micron- to nanosize osseointegrated features, such as surface roughness, fibers, porosity, and particles, have been fused with implants for improving the osseointegration of an implant with the host tissue in orthopedics and dentistry. The effects of fibers and loading angles on the interface fracture toughness of implant–cement specimens with and without fibers at the interface are not yet known. Such studies are important for the design of a long-lasting implant for orthopedic applications. The goal of this study was to improve the fracture toughness of an implant–cement interface by deposition of micron- to nanosize fibers on an implant surface. There were two objectives in the study: 1) to evaluate the influence of fibers on the fracture toughness of implant–cement interfaces with and without fibers at the interfaces, and 2) to evaluate the influence of loading angles on implant–cement interfaces with and without fibers at the interfaces. This study used titanium as the implant, poly(methyl methacrylate) (PMMA) as cement, and polycaprolactone (PCL) as fiber materials. An electrospinning unit was fabricated for the deposition of PCL unidirectional fibers on titanium (Ti) plates. The Evex tensile test stage was used to determine the interface fracture toughness (KC) of Ti–PMMA with and without PCL fibers at 0°, 45°, and 90° loading angles, referred to in this article as tension, mixed, and shear tests. The study did not find any significant interaction between fiber and loading angles (P>0.05), although there was a significant difference in the KC means of Ti–PMMA samples for the loading angles (P<0.05). The study also found a significant difference in the KC means of Ti–PMMA samples with and without fibers (P<0.05). The results showed that the addition of the micron- to nanosize PCL fibers on Ti improved the quality of the Ti–PMMA union. The results of the study are essential for fatigue testing and finite-element analysis of implant–cement interfaces to evaluate the performance of orthopedic and orthodontic implants. PMID:24729704

Asynchronous brain-computer interface for cognitive assessment in people with cerebral palsy

NASA Astrophysics Data System (ADS)

Alcaide-Aguirre, R. E.; Warschausky, S. A.; Brown, D.; Aref, A.; Huggins, J. E.

2017-12-01

Objective. Typically, clinical measures of cognition require motor or speech responses. Thus, a significant percentage of people with disabilities are not able to complete standardized assessments. This situation could be resolved by employing a more accessible test administration method, such as a brain-computer interface (BCI). A BCI can circumvent motor and speech requirements by translating brain activity to identify a subject’s response. By eliminating the need for motor or speech input, one could use a BCI to assess an individual who previously did not have access to clinical tests. Approach. We developed an asynchronous, event-related potential BCI-facilitated administration procedure for the peabody picture vocabulary test (PPVT-IV). We then tested our system in typically developing individuals (N  =  11), as well as people with cerebral palsy (N  =  19) to compare results to the standardized PPVT-IV format and administration. Main results. Standard scores on the BCI-facilitated PPVT-IV, and the standard PPVT-IV were highly correlated (r  =  0.95, p  <  0.001), with a mean difference of 2.0  ±  6.4 points, which is within the standard error of the PPVT-IV. Significance. Thus, our BCI-facilitated PPVT-IV provided comparable results to the standard PPVT-IV, suggesting that populations for whom standardized cognitive tests are not accessible could benefit from our BCI-facilitated approach.

On the Material Characterisation of Wind Turbine Blade Coatings: The Effect of Interphase Coating–Laminate Adhesion on Rain Erosion Performance

PubMed Central

Cortés, Enrique; Sánchez, Fernando; Madramany, Borja

2017-01-01

Rain erosion damage, caused by repeated droplet impact on wind turbine blades, is a major cause for concern, even more so at offshore locations with larger blades and higher tip speeds. Due to the negative economic influence of blade erosion, all wind turbine Original Equipment Manufacturers (OEMs) are actively seeking solutions. In most cases, since the surface coating plays a decisive role in the blade manufacture and overall performance, it has been identified as an area where a solution may be obtained. In this research, two main coating technologies have been considered: In-mould coatings (Gel coating) applied during moulding on the entire blade surface and the post-mould coatings specifically developed for Leading Edge Protection (LEP). The coating adhesion and erosion is affected by the shock waves created by the collapsing water droplets on impact. The stress waves are reflected and transmitted to the laminate substrate, so microstructural discontinuities in coating layers and interfaces play a key role on its degradation and may accelerate erosion by delamination. Analytical and numerical models are commonly used to relate lifetime prediction and to identify suitable coating and composite substrate combinations based on their potential stress reduction on the interface. Nevertheless, in order to use them, it is necessary to measure the contact adhesion resistance of the multi-layered system interfaces. The rain erosion performance is assessed using an accelerated testing technique, whereby the test material is repeatedly impacted at high speed with water droplets in a Whirling Arm Rain Erosion Rig (WARER). The materials, specifically the coating–laminate interphase region and acoustic properties, are further characterised by several laboratory tests, including Differential Scanning Calorimetry (DSC), pull-off testing, peeling–adhesion testing and nanoindentation testing. This body of work includes a number of case studies. The first case study compares two of the main coating technologies used in industry (i.e., gel coating and LEP); the second case investigates the effects of the in-mould gel coating curing; and the third considers the inclusion of a primer layer on a LEP configuration system. Following these case studies, the LEP is found to be a far superior coating due to its appropriate mechanical and acoustic properties and the interface between the coating and the substrate is highlighted as a key aspect, as poor adhesion can lead to delamination and, ultimately, premature failure of the coating. PMID:28956841

On the Material Characterisation of Wind Turbine Blade Coatings: The Effect of Interphase Coating-Laminate Adhesion on Rain Erosion Performance.

PubMed

Cortés, Enrique; Sánchez, Fernando; O'Carroll, Anthony; Madramany, Borja; Hardiman, Mark; Young, Trevor M

2017-09-28

Rain erosion damage, caused by repeated droplet impact on wind turbine blades, is a major cause for concern, even more so at offshore locations with larger blades and higher tip speeds. Due to the negative economic influence of blade erosion, all wind turbine Original Equipment Manufacturers (OEMs) are actively seeking solutions. In most cases, since the surface coating plays a decisive role in the blade manufacture and overall performance, it has been identified as an area where a solution may be obtained. In this research, two main coating technologies have been considered: In-mould coatings (Gel coating) applied during moulding on the entire blade surface and the post-mould coatings specifically developed for Leading Edge Protection (LEP). The coating adhesion and erosion is affected by the shock waves created by the collapsing water droplets on impact. The stress waves are reflected and transmitted to the laminate substrate, so microstructural discontinuities in coating layers and interfaces play a key role on its degradation and may accelerate erosion by delamination. Analytical and numerical models are commonly used to relate lifetime prediction and to identify suitable coating and composite substrate combinations based on their potential stress reduction on the interface. Nevertheless, in order to use them, it is necessary to measure the contact adhesion resistance of the multi-layered system interfaces. The rain erosion performance is assessed using an accelerated testing technique, whereby the test material is repeatedly impacted at high speed with water droplets in a Whirling Arm Rain Erosion Rig (WARER). The materials, specifically the coating-laminate interphase region and acoustic properties, are further characterised by several laboratory tests, including Differential Scanning Calorimetry (DSC), pull-off testing, peeling-adhesion testing and nanoindentation testing. This body of work includes a number of case studies. The first case study compares two of the main coating technologies used in industry (i.e., gel coating and LEP); the second case investigates the effects of the in-mould gel coating curing; and the third considers the inclusion of a primer layer on a LEP configuration system. Following these case studies, the LEP is found to be a far superior coating due to its appropriate mechanical and acoustic properties and the interface between the coating and the substrate is highlighted as a key aspect, as poor adhesion can lead to delamination and, ultimately, premature failure of the coating.

75 FR 33898 - Agency Information Collection (VA Loan Electronic Reporting Interface (VALERI) System) Activity...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-15

... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-0021] Agency Information Collection (VA Loan Electronic Reporting Interface (VALERI) System) Activity Under OMB Review AGENCY: Veterans Benefits... Administration (VBA), Department of Veterans Affairs, will submit the collection of information abstracted below...

SRG110 Stirling Generator Dynamic Simulator Vibration Test Results and Analysis Correlation

NASA Technical Reports Server (NTRS)

Suarez, Vicente J.; Lewandowski, Edward J.; Callahan, John

2006-01-01

The U.S. Department of Energy (DOE), Lockheed Martin (LM), and NASA Glenn Research Center (GRC) have been developing the Stirling Radioisotope Generator (SRG110) for use as a power system for space science missions. The launch environment enveloping potential missions results in a random input spectrum that is significantly higher than historical RPS launch levels and is a challenge for designers. Analysis presented in prior work predicted that tailoring the compliance at the generator-spacecraft interface reduced the dynamic response of the system thereby allowing higher launch load input levels and expanding the range of potential generator missions. To confirm analytical predictions, a dynamic simulator representing the generator structure, Stirling convertors and heat sources was designed and built for testing with and without a compliant interface. Finite element analysis was performed to guide the generator simulator and compliant interface design so that test modes and frequencies were representative of the SRG110 generator. This paper presents the dynamic simulator design, the test setup and methodology, test article modes and frequencies and dynamic responses, and post-test analysis results. With the compliant interface, component responses to an input environment exceeding the SRG110 qualification level spectrum were all within design allowables. Post-test analysis included finite element model tuning to match test frequencies and random response analysis using the test input spectrum. Analytical results were in good overall agreement with the test results and confirmed previous predictions that the SRG110 power system may be considered for a broad range of potential missions, including those with demanding launch environments.

SRG110 Stirling Generator Dynamic Simulator Vibration Test Results and Analysis Correlation

NASA Technical Reports Server (NTRS)

Lewandowski, Edward J.; Suarez, Vicente J.; Goodnight, Thomas W.; Callahan, John

2007-01-01

The U.S. Department of Energy (DOE), Lockheed Martin (LM), and NASA Glenn Research Center (GRC) have been developing the Stirling Radioisotope Generator (SRG110) for use as a power system for space science missions. The launch environment enveloping potential missions results in a random input spectrum that is significantly higher than historical radioisotope power system (RPS) launch levels and is a challenge for designers. Analysis presented in prior work predicted that tailoring the compliance at the generator-spacecraft interface reduced the dynamic response of the system thereby allowing higher launch load input levels and expanding the range of potential generator missions. To confirm analytical predictions, a dynamic simulator representing the generator structure, Stirling convertors and heat sources were designed and built for testing with and without a compliant interface. Finite element analysis was performed to guide the generator simulator and compliant interface design so that test modes and frequencies were representative of the SRG110 generator. This paper presents the dynamic simulator design, the test setup and methodology, test article modes and frequencies and dynamic responses, and post-test analysis results. With the compliant interface, component responses to an input environment exceeding the SRG110 qualification level spectrum were all within design allowables. Post-test analysis included finite element model tuning to match test frequencies and random response analysis using the test input spectrum. Analytical results were in good overall agreement with the test results and confirmed previous predictions that the SRG110 power system may be considered for a broad range of potential missions, including those with demanding launch environments.

A Simulation Base Investigation of High Latency Space Systems Operations

NASA Technical Reports Server (NTRS)

Li, Zu Qun; Crues, Edwin Z.; Bielski, Paul; Moore, Michael

2017-01-01

NASA's human space program has developed considerable experience with near Earth space operations. Although NASA has experience with deep space robotic missions, NASA has little substantive experience with human deep space operations. Even in the Apollo program, the missions lasted only a few weeks and the communication latencies were on the order of seconds. Human missions beyond the relatively close confines of the Earth-Moon system will involve missions with durations measured in months and communications latencies measured in minutes. To minimize crew risk and to maximize mission success, NASA needs to develop a better understanding of the implications of these types of mission durations and communication latencies on vehicle design, mission design and flight controller interaction with the crew. To begin to address these needs, NASA performed a study using a physics-based subsystem simulation to investigate the interactions between spacecraft crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation, built with a subsystem modeling tool developed at NASA's Johnson Space Center, models the life support system of a Mars transit vehicle. The simulation contains models of the cabin atmosphere and pressure control system, electrical power system, drinking and waste water systems, internal and external thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the vehicle subsystems; 2) a mission control center interface with data transport delays up to 15 minutes each way; 3) a real-time simulation test conductor interface that can be use to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission between July 18th and Aug 3rd of year 2016. The NEEMO mission provides ideal conditions for this study with crew in the loop, an active control center, and real-time flow of high latency communications and data. NEEMO crew and ground support will work through procedures including activation of the transit vehicle power system, opening the hatch between the transit vehicle and a Mars ascent vehicle, transferring simulated crewmembers between vehicles, overcoming subsystem malfunctions, sending simulated crewmember on extra-vehicular activities, and other housekeeping activities. This study is enhancing the understanding of high latency operations and the advantages and disadvantages of different communication methods. It is also providing results that will help improve the design of simulation interfaces and inform the design of Mars transit vehicles.

Modelling of the batch biosorption system: study on exchange of protons with cell wall-bound mineral ions.

PubMed

Mishra, Vishal

2015-01-01

The interchange of the protons with the cell wall-bound calcium and magnesium ions at the interface of solution/bacterial cell surface in the biosorption system at various concentrations of protons has been studied in the present work. A mathematical model for establishing the correlation between concentration of protons and active sites was developed and optimized. The sporadic limited residence time reactor was used to titrate the calcium and magnesium ions at the individual data point. The accuracy of the proposed mathematical model was estimated using error functions such as nonlinear regression, adjusted nonlinear regression coefficient, the chi-square test, P-test and F-test. The values of the chi-square test (0.042-0.017), P-test (<0.001-0.04), sum of square errors (0.061-0.016), root mean square error (0.01-0.04) and F-test (2.22-19.92) reported in the present research indicated the suitability of the model over a wide range of proton concentrations. The zeta potential of the bacterium surface at various concentrations of protons was observed to validate the denaturation of active sites.

Development of the Work-Family Interface Scale.

ERIC Educational Resources Information Center

Curbow, Barbara; McDonnell, Karen; Spratt, Kai; Griffin, Joan; Agnew, Jacqueline

2003-01-01

Developed and tested a 20-item measure of work-family interface with child care providers. Confirmed five factors: general overload, conflict of family to work, spillover of family to work, spillover of work to family, and conflict of work to family. Regression lines for low, medium, and high levels of work-family interface indicated that high…

Exploratory Usability Testing of User Interface Options in LibGuides 2

ERIC Educational Resources Information Center

Thorngate, Sarah; Hoden, Allison

2017-01-01

Online research guides offer librarians a way to provide digital researchers with point-of-need support. If these guides are to support student learning well, it is critical that they provide an effective user experience. This article details the results of an exploratory comparison study that tested three key user interface options in LibGuides…

40 CFR 60.2710 - How do I demonstrate continuous compliance with the emission limitations and the operating limits?

Code of Federal Regulations, 2011 CFR

2011-07-01

... performance test deadline for PM CEMS. Relative accuracy testing for other CEMS need not be repeated if that... system. (i) Installation of the continuous monitoring system sampling probe or other interface at a... equipment specifications for the sample interface, the pollutant concentration or parametric signal analyzer...

Ergonomics Factors in English as a Foreign Language Testing: The Case of PLEVALEX

ERIC Educational Resources Information Center

Garcia Laborda, Jesus; Magal-Royo, Teresa; de Siqueira Rocha, Jose Macario; Alvarez, Miguel Fernandez

2010-01-01

Although much has been said about ergonomics in interface and in computer tools and interface design, very few articles in major journals have addressed this topic in relation to language testing. This article describes an experiment carried out at the Polytechnic University of Valencia, Spain, in which 27 Media and Communication students provided…

A user interface for the Kansas Geological Survey slug test model.

PubMed

Esling, Steven P; Keller, John E

2009-01-01

The Kansas Geological Survey (KGS) developed a semianalytical solution for slug tests that incorporates the effects of partial penetration, anisotropy, and the presence of variable conductivity well skins. The solution can simulate either confined or unconfined conditions. The original model, written in FORTRAN, has a text-based interface with rigid input requirements and limited output options. We re-created the main routine for the KGS model as a Visual Basic macro that runs in most versions of Microsoft Excel and built a simple-to-use Excel spreadsheet interface that automatically displays the graphical results of the test. A comparison of the output from the original FORTRAN code to that of the new Excel spreadsheet version for three cases produced identical results.

Alignment and testing of critical interface fixtures for the James Webb Space Telescope

NASA Astrophysics Data System (ADS)

McLean, Kyle; Bagdanove, Paul; Berrier, Joshua; Cofie, Emmanuel; Glassman, Tiffany; Hadjimichael, Theodore; Johnson, Eric; Levi, Joshua; Lo, Amy; McMann, Joseph; Ohl, Raymond; Osgood, Dean; Parker, James; Redman, Kevin; Roberts, Vicki; Stephens, Matthew; Sutton, Adam; Wenzel, Greg; Young, Jerrod

2017-08-01

NASA's James Webb Space Telescope (JWST) is a 6.5m diameter, segmented, deployable telescope for cryogenic IR space astronomy. The JWST Observatory architecture includes the Primary Mirror Backplane Support Structure (PMBSS) and Integrated Science Instrument Module (ISIM) Electronics Compartment (IEC) which is designed to integrate to the spacecraft bus via six cup/cone interfaces. Prior to integration to the spacecraft bus, the JWST observatory must undergo environmental testing, handling, and transportation. Multiple fixtures were developed to support these tasks including the vibration fixture and handling and integration fixture (HIF). This work reports on the development of the nominal alignment of the six interfaces and metrology operations performed for the JWST observatory to safely integrate them for successful environmental testing.

ISS Interface Mechanisms and their Heritage

NASA Technical Reports Server (NTRS)

Cook, John G.; Aksamentov, Valery; Hoffman, Thomas; Bruner, Wes

2011-01-01

The International Space Station, by nurturing technological development of a variety of pressurized and unpressurized interface mechanisms fosters "competition at the technology level". Such redundancy and diversity allows for the development and testing of mechanisms that might be used for future exploration efforts. The International Space Station, as a test-bed for exploration, has 4 types of pressurized interfaces between elements and 6 unpressurized attachment mechanisms. Lessons learned from the design, test and operations of these mechanisms will help inform the design for a new international standard pressurized docking mechanism for the NASA Docking System. This paper will examine the attachment mechanisms on the ISS and their attributes. It will also look ahead at the new NASA docking system and trace its lineage to heritage mechanisms.

Alignment and Testing of Critical Interface Fixtures for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Mclean, Kyle; Bagdanove, Paul; Berrier, Joshua; Cofie, Emmanuel; Glassman, Tiffany; Hadjimichael, Theodore; Johnson, Eric; Levi, Joshua; Lo, Amy; McMann, Joseph;

Alignment and Testing of Critical Interface Fixtures for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Mclean, Kyle; Bagdanove, Paul; Berrier, Joshua; Cofie, Emmanuel; Glassman, Tiffany; Hadjimichael, Theodore; Johnson, Eric; Levi, Joshua; Lo, Amy; McMann, Joseph;

Engineering platform and experimental protocol for design and evaluation of a neurally-controlled powered transfemoral prosthesis.

PubMed

Zhang, Fan; Liu, Ming; Harper, Stephen; Lee, Michael; Huang, He

2014-07-22

To enable intuitive operation of powered artificial legs, an interface between user and prosthesis that can recognize the user's movement intent is desired. A novel neural-machine interface (NMI) based on neuromuscular-mechanical fusion developed in our previous study has demonstrated a great potential to accurately identify the intended movement of transfemoral amputees. However, this interface has not yet been integrated with a powered prosthetic leg for true neural control. This study aimed to report (1) a flexible platform to implement and optimize neural control of powered lower limb prosthesis and (2) an experimental setup and protocol to evaluate neural prosthesis control on patients with lower limb amputations. First a platform based on a PC and a visual programming environment were developed to implement the prosthesis control algorithms, including NMI training algorithm, NMI online testing algorithm, and intrinsic control algorithm. To demonstrate the function of this platform, in this study the NMI based on neuromuscular-mechanical fusion was hierarchically integrated with intrinsic control of a prototypical transfemoral prosthesis. One patient with a unilateral transfemoral amputation was recruited to evaluate our implemented neural controller when performing activities, such as standing, level-ground walking, ramp ascent, and ramp descent continuously in the laboratory. A novel experimental setup and protocol were developed in order to test the new prosthesis control safely and efficiently. The presented proof-of-concept platform and experimental setup and protocol could aid the future development and application of neurally-controlled powered artificial legs.

Adaptation of the Camera Link Interface for Flight-Instrument Applications

NASA Technical Reports Server (NTRS)

Randall, David P.; Mahoney, John C.

2010-01-01

COTS (commercial-off-the-shelf) hard ware using an industry-standard Camera Link interface is proposed to accomplish the task of designing, building, assembling, and testing electronics for an airborne spectrometer that would be low-cost, but sustain the required data speed and volume. The focal plane electronics were designed to support that hardware standard. Analysis was done to determine how these COTS electronics could be interfaced with space-qualified camera electronics. Interfaces available for spaceflight application do not support the industry standard Camera Link interface, but with careful design, COTS EGSE (electronics ground support equipment), including camera interfaces and camera simulators, can still be used.

The space shuttle payload planning working groups. Volume 10: Space technology

NASA Technical Reports Server (NTRS)

1973-01-01

The findings and recommendations of the Space Technology group of the space shuttle payload planning activity are presented. The elements of the space technology program are: (1) long duration exposure facility, (2) advanced technology laboratory, (3) physics and chemistry laboratory, (4) contamination experiments, and (5) laser information/data transmission technology. The space technology mission model is presented in tabular form. The proposed experiments to be conducted by each test facility are described. Recommended approaches for user community interfacing are included.

KSC-03pd0010

NASA Image and Video Library

2003-01-04

KENNEDY SPACE CENTER, FLA. - STS-114 Commander Eileen Collins looks over the windshield in Atlantis. She and other crew members are at KSC to take part in Crew Equipment Interface Test activities, which include checking out the payload and orbiter. STS-114 is a utilization and logistics flight (ULF-1) that will carry Multi-Purpose Logistics Module Raffaello and the External Stowage Platform (ESP-2), as well as the Expedition 7 crew, to the International Space Station. Launch is targeted for March 1, 2003.

KSC-03pd0013

NASA Image and Video Library

2003-01-04

KENNEDY SPACE CENTER, FLA. -- STS-114 Pilot James Kelly and Commander Eileen Collins look over the windshield in Atlantis. They and other crew members are at KSC to take part in Crew Equipment Interface Test activities, which include checking out the payload and orbiter. STS-114 is a utilization and logistics flight (ULF-1) that will carry Multi-Purpose Logistics Module Raffaello and the External Stowage Platform (ESP-2), as well as the Expedition 7 crew, to the International Space Station. Launch is targeted for March 1, 2003.

KSC-03pd0011

NASA Image and Video Library

2003-01-04

KENNEDY SPACE CENTER, FLA. - STS-114 Commander Eileen Collins (foreground) checks out the windshield in Atlantis. She and other crew members are at KSC to take part in Crew Equipment Interface Test activities, which include checking out the payload and orbiter. STS-114 is a utilization and logistics flight (ULF-1) that will carry Multi-Purpose Logistics Module Raffaello and the External Stowage Platform (ESP-2), as well as the Expedition 7 crew, to the International Space Station. Launch is targeted for March 1, 2003.

Astronaut tool development: An orbital replaceable unit-portable handhold

NASA Technical Reports Server (NTRS)

Redmon, John W., Jr.

1989-01-01

A tool to be used during astronaut Extra-Vehicular Activity (EVA) replacement of spent or defective electrical/electronic component boxes is described. The generation of requirements and design philosophies are detailed, as well as specifics relating to mechanical development, interface verifications, testing, and astronaut feedback. Findings are presented in the form of: (1) a design which is universally applicable to spacecraft component replacement, and (2) guidelines that the designer of orbital replacement units might incorporate to enhance spacecraft on-orbit maintainability and EVA mission safety.

Interfacing Computer-Assisted Drafting and Design with the Building Loads Analysis and System Thermodynamics (BLAST) Program

DTIC Science & Technology

1992-10-01

Manual CI APPENDIX D: Drawing Navigator Field Test D1 DISTRIBUTION Accesion For NTIS CRA&I OTIC TAB Unannouncea JustiteCdtOn By Distribution I "".i•I...methods replace manual methods, the automation will handle the data for the designer, thus reducing error and increasing throughput. However, the two...actively move data from one automation tool (CADD) to the other (the analysis program). This intervention involves a manual rekeying of data already in

KSC-03PD-0186

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. - STS-115 Mission Specialist Joseph Tanner (center) works a piece of equipment during Crew Equipment Interface Test activities in the Space Station Processing Facility. On the right is Mission Specialist Heidemarie Stefanyshyn-Piper. The mission will deliver the second port truss segment, the P3/P4 Truss, to attach to the first port truss segment, the P1 Truss, as well as deploy solar array set 2A and 4A. Launch on Space Shuttle Endeavour is scheduled for May 23, 2003.

The STS-92 crew is ready to leave KSC after CEIT

NASA Technical Reports Server (NTRS)

2000-01-01

STS-92 Pilot Pam Melroy poses at the Shuttle Landing Facility before flying back to Houston. She and other crew members completed their Crew Equipment Interface Test activities, looking over their mission payload and related equipment. STS-92 is scheduled to launch Oct. 5 on Shuttle Discovery from Launch Pad 39A on the fifth flight to the International Space Station. Discovery will carry the Integrated Truss Structure (ITS) Z1, the PMA-3, Ku-band Communications System, and Control Moment Gyros (CMGs).

Use of Plastic Capillaries for Macromolecular Crystallization

NASA Technical Reports Server (NTRS)

Potter, Rachel R.; Hong, Young-Soo; Ciszak, Ewa M.

2003-01-01

Methods of crystallization of biomolecules in plastic capillaries (Nalgene 870 PFA tubing) are presented. These crystallization methods used batch, free-interface liquid- liquid diffusion alone, or a combination with vapor diffusion. Results demonstrated growth of crystals of test proteins such as thaumatin and glucose isomerase, as well as protein studied in our laboratory such dihydrolipoamide dehydrogenase. Once the solutions were loaded in capillaries, they were stored in the tubes in frozen state at cryogenic temperatures until the desired time of activation of crystallization experiments.

KSC-01pp0936

NASA Image and Video Library

2001-04-27

KENNEDY SPACE CENTER, FLA. -- After their arrival at the Shuttle Landing Facility, the STS-104 crew takes time to pose for a photo. Standing, left to right, are Mission Specialist Janet Kavandi, Pilot Charles Hobaugh, Commander Steven Lindsey, and Mission Specialists Michael Gernhardt and James Reilly. They are at KSC to continue Crew Equipment Interface Test activities such as payload familiarization. The airlock is the primary payload on their mission, scheduled to launch no earlier than June 14, 2001, from Launch Pad 39B

Interfacial Energy Alignment at the ITO/Ultra-Thin Electron Selective Dielectric Layer Interface and Its Effect on the Efficiency of Bulk-Heterojunction Organic Solar Cells.

PubMed

Itoh, Eiji; Goto, Yoshinori; Saka, Yusuke; Fukuda, Katsutoshi

2016-04-01

We have investigated the photovoltaic properties of an inverted bulk heterojunction (BHJ) cell in a device with an indium-tin-oxide (ITO)/electron selective layer (ESL)/P3HT:PCBM active layer/MoOx/Ag multilayered structure. The insertion of only single layer of poly(diallyl-dimethyl-ammonium chloride) (PDDA) cationic polymer film (or poly(ethyleneimine) (PEI) polymeric interfacial dipole layer) and titanium oxide nanosheet (TN) films as an ESL effectively improved cell performance. Abnormal S-shaped curves were observed in the inverted BHJ cells owing to the contact resistance across the ITO/active layer interface and the ITO/PDDA/TN/active layer interface. The series resistance across the ITO/ESL interface in the inverted BHJ cell was successfully reduced using an interfacial layer with a positively charged surface potential with respect to ITO base electrode. The positive dipole in PEI and the electronic charge phenomena at the electrophoretic deposited TN (ED-TN) films on ITO contributed to the reduction of the contact resistance at the electrode interface. The surface potential measurement revealed that the energy alignment by the transfer of electronic charges from the ED-TN to the base electrodes. The insertion of the ESL with a large positive surface potential reduced the potential barrier for the electron injection at ITO/TN interface and it improved the photovoltaic properties of the inverted cell with an ITO/TN/active layer/MoOx/Ag structure.

DPubChem: a web tool for QSAR modeling and high-throughput virtual screening.

PubMed

Soufan, Othman; Ba-Alawi, Wail; Magana-Mora, Arturo; Essack, Magbubah; Bajic, Vladimir B

2018-06-14

High-throughput screening (HTS) performs the experimental testing of a large number of chemical compounds aiming to identify those active in the considered assay. Alternatively, faster and cheaper methods of large-scale virtual screening are performed computationally through quantitative structure-activity relationship (QSAR) models. However, the vast amount of available HTS heterogeneous data and the imbalanced ratio of active to inactive compounds in an assay make this a challenging problem. Although different QSAR models have been proposed, they have certain limitations, e.g., high false positive rates, complicated user interface, and limited utilization options. Therefore, we developed DPubChem, a novel web tool for deriving QSAR models that implement the state-of-the-art machine-learning techniques to enhance the precision of the models and enable efficient analyses of experiments from PubChem BioAssay database. DPubChem also has a simple interface that provides various options to users. DPubChem predicted active compounds for 300 datasets with an average geometric mean and F 1 score of 76.68% and 76.53%, respectively. Furthermore, DPubChem builds interaction networks that highlight novel predicted links between chemical compounds and biological assays. Using such a network, DPubChem successfully suggested a novel drug for the Niemann-Pick type C disease. DPubChem is freely available at www.cbrc.kaust.edu.sa/dpubchem .

Learner-Interface Interaction for Technology-Enhanced Active Learning

ERIC Educational Resources Information Center

Sinha, Neelu; Khreisat, Laila; Sharma, Kiron

2009-01-01

Neelu Sinha, Laila Khreisat, and Kiron Sharma describe how learner-interface interaction promotes active learning in computer science education. In a pilot study using technology that combines DyKnow software with a hardware platform of pen-enabled HP Tablet notebook computers, Sinha, Khreisat, and Sharma created dynamic learning environments by…

Development of an aeroelastic methodology for surface morphing rotors

NASA Astrophysics Data System (ADS)

Cook, James R.

Helicopter performance capabilities are limited by maximum lift characteristics and vibratory loading. In high speed forward flight, dynamic stall and transonic flow greatly increase the amplitude of vibratory loads. Experiments and computational simulations alike have indicated that a variety of active rotor control devices are capable of reducing vibratory loads. For example, periodic blade twist and flap excitation have been optimized to reduce vibratory loads in various rotors. Airfoil geometry can also be modified in order to increase lift coefficient, delay stall, or weaken transonic effects. To explore the potential benefits of active controls, computational methods are being developed for aeroelastic rotor evaluation, including coupling between computational fluid dynamics (CFD) and computational structural dynamics (CSD) solvers. In many contemporary CFD/CSD coupling methods it is assumed that the airfoil is rigid to reduce the interface by single dimension. Some methods retain the conventional one-dimensional beam model while prescribing an airfoil shape to simulate active chord deformation. However, to simulate the actual response of a compliant airfoil it is necessary to include deformations that originate not only from control devices (such as piezoelectric actuators), but also inertial forces, elastic stresses, and aerodynamic pressures. An accurate representation of the physics requires an interaction with a more complete representation of loads and geometry. A CFD/CSD coupling methodology capable of communicating three-dimensional structural deformations and a distribution of aerodynamic forces over the wetted blade surface has not yet been developed. In this research an interface is created within the Fully Unstructured Navier-Stokes (FUN3D) solver that communicates aerodynamic forces on the blade surface to University of Michigan's Nonlinear Active Beam Solver (UM/NLABS -- referred to as NLABS in this thesis). Interface routines are developed for transmission of force and deflection information to achieve an aeroelastic coupling updated at each time step. The method is validated first by comparing the integrated aerodynamic work at CFD and CSD nodes to verify work conservation across the interface. Second, the method is verified by comparing the sectional blade loads and deflections of a rotor in hover and in forward flight with experimental data. Finally, stability analyses for pitch/plunge flutter and camber flutter are performed with comprehensive CSD/low-order-aerodynamics and tightly coupled CFD/CSD simulations and compared to analytical solutions of Peters' thin airfoil theory to verify proper aeroelastic behavior. The effects of simple harmonic camber actuation are examined and compared to the response predicted by Peters' finite-state (F-S) theory. In anticipation of active rotor experiments inside enclosed facilities, computational simulations are performed to evaluate the capability of CFD for accurately simulating flow inside enclosed volumes. A computational methodology for accurately simulating a rotor inside a test chamber is developed to determine the influence of test facility components and turbulence modeling and performance predictions. A number of factors that influence the physical accuracy of the simulation, such as temporal resolution, grid resolution, and aeroelasticity are also evaluated.

Importance of curvature evaluation scale for predictive simulations of dynamic gas-liquid interfaces

NASA Astrophysics Data System (ADS)

Owkes, Mark; Cauble, Eric; Senecal, Jacob; Currie, Robert A.

2018-07-01

The effect of the scale used to compute the interfacial curvature on the prediction of dynamic gas-liquid interfaces is investigated. A new interface curvature calculation methodology referred to herein as the Adjustable Curvature Evaluation Scale (ACES) is proposed. ACES leverages a weighted least squares regression to fit a polynomial through points computed on the volume-of-fluid representation of the gas-liquid interface. The interface curvature is evaluated from this polynomial. Varying the least squares weight with distance from the location where the curvature is being computed, adjusts the scale the curvature is evaluated on. ACES is verified using canonical static test cases and compared against second- and fourth-order height function methods. Simulations of dynamic interfaces, including a standing wave and oscillating droplet, are performed to assess the impact of the curvature evaluation scale for predicting interface motions. ACES and the height function methods are combined with two different unsplit geometric volume-of-fluid (VoF) schemes that define the interface on meshes with different levels of refinement. We find that the results depend significantly on curvature evaluation scale. Particularly, the ACES scheme with a properly chosen weight function is accurate, but fails when the scale is too small or large. Surprisingly, the second-order height function method is more accurate than the fourth-order variant for the dynamic tests even though the fourth-order method performs better for static interfaces. Comparing the curvature evaluation scale of the second- and fourth-order height function methods, we find the second-order method is closer to the optimum scale identified with ACES. This result suggests that the curvature scale is driving the accuracy of the dynamics. This work highlights the importance of studying numerical methods with realistic (dynamic) test cases and that the interactions of the various discretizations is as important as the accuracy of one part of the discretization.

Design and Test of an Event Detector for the ReflectoActive Seals System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stinson, Brad J

2006-05-01

The purpose of this thesis was to research, design, develop and test a novel instrument for detecting fiber optic loop continuity and spatially locating fiber optic breaches. The work is for an active seal system called ReflectoActive Seals whose purpose is to provide real time container tamper indication. A Field Programmable Gate Array was used to implement a loop continuity detector and a spatial breach locator based on a high acquisition speed single photon counting optical time domain reflectometer. Communication and other control features were added in order to create a usable instrument that met defined requirements. A host graphicalmore » user interface was developed to illustrate system use and performance. The resulting device meets performance specifications by exhibiting a dynamic range of 27dB and a spatial resolution of 1.5 ft. The communication scheme used expands installation options and allows the device to communicate to a central host via existing Local Area Networks and/or the Internet.« less

Design and Test of an Event Detector and Locator for the ReflectoActive Seals System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stinson, Brad J

2006-06-01

The purpose of this work was to research, design, develop and test a novel instrument for detecting fiber optic loop continuity and spatially locating fiber optic breaches. The work is for an active seal system called ReflectoActive{trademark} Seals whose purpose is to provide real time container tamper indication. A Field Programmable Gate Array was used to implement a loop continuity detector and a spatial breach locator based on a high acquisition speed single photon counting optical time domain reflectometer. Communication and other control features were added in order to create a usable instrument that met defined requirements. A host graphicalmore » user interface was developed to illustrate system use and performance. The resulting device meets performance specifications by exhibiting a dynamic range of 27dB and a spatial resolution of 1.5 ft. The communication scheme used expands installation options and allows the device to communicate to a central host via existing Local Area Networks and/or the Internet.« less

SOCR Analyses - an Instructional Java Web-based Statistical Analysis Toolkit.

PubMed

Chu, Annie; Cui, Jenny; Dinov, Ivo D

2009-03-01

The Statistical Online Computational Resource (SOCR) designs web-based tools for educational use in a variety of undergraduate courses (Dinov 2006). Several studies have demonstrated that these resources significantly improve students' motivation and learning experiences (Dinov et al. 2008). SOCR Analyses is a new component that concentrates on data modeling and analysis using parametric and non-parametric techniques supported with graphical model diagnostics. Currently implemented analyses include commonly used models in undergraduate statistics courses like linear models (Simple Linear Regression, Multiple Linear Regression, One-Way and Two-Way ANOVA). In addition, we implemented tests for sample comparisons, such as t-test in the parametric category; and Wilcoxon rank sum test, Kruskal-Wallis test, Friedman's test, in the non-parametric category. SOCR Analyses also include several hypothesis test models, such as Contingency tables, Friedman's test and Fisher's exact test.The code itself is open source (http://socr.googlecode.com/), hoping to contribute to the efforts of the statistical computing community. The code includes functionality for each specific analysis model and it has general utilities that can be applied in various statistical computing tasks. For example, concrete methods with API (Application Programming Interface) have been implemented in statistical summary, least square solutions of general linear models, rank calculations, etc. HTML interfaces, tutorials, source code, activities, and data are freely available via the web (www.SOCR.ucla.edu). Code examples for developers and demos for educators are provided on the SOCR Wiki website.In this article, the pedagogical utilization of the SOCR Analyses is discussed, as well as the underlying design framework. As the SOCR project is on-going and more functions and tools are being added to it, these resources are constantly improved. The reader is strongly encouraged to check the SOCR site for most updated information and newly added models.

Integrated Information Support System (IISS). Volume 8. User Interface Subsystem. Part 14. Virtual Terminal Unit Test Plan

DTIC Science & Technology

1990-09-30

Dynamics Research Corporation: Jones, L.. Glandorf, F. 3a. TYPE OF REPORT 113b. TIME COVERED 114. DATE OF REPORT (Yr.,Mo..Day) 15. PAGE COUNT Final...specific software modules written for each type of real terminal supported. Virtual Terminal Interface: the callable interface to the Virtual Terminal...2000;60000;2;0;100;100;5000;0;0;0;0;0;10 "v-Testing2- DVF - View Fill Area: <ESC>[5;1;2000;50000;20000;30000;20000;50000; 2000;30000&v DVM - View Markers: <ESC

Bubble memory module

NASA Technical Reports Server (NTRS)

Bohning, O. D.; Becker, F. J.

1980-01-01

Design, fabrication and test of partially populated prototype recorder using 100 kilobit serial chips is described. Electrical interface, operating modes, and mechanical design of several module configurations are discussed. Fabrication and test of the module demonstrated the practicality of multiplexing resulting in lower power, weight, and volume. This effort resulted in the completion of a module consisting of a fully engineered printed circuit storage board populated with 5 of 8 possible cells and a wire wrapped electronics board. Interface of the module is 16 bits parallel at a maximum of 1.33 megabits per second data rate on either of two interface buses.

Body-Machine Interfaces after Spinal Cord Injury: Rehabilitation and Brain Plasticity.

PubMed

Seáñez-González, Ismael; Pierella, Camilla; Farshchiansadegh, Ali; Thorp, Elias B; Wang, Xue; Parrish, Todd; Mussa-Ivaldi, Ferdinando A

2016-12-19

The purpose of this study was to identify rehabilitative effects and changes in white matter microstructure in people with high-level spinal cord injury following bilateral upper-extremity motor skill training. Five subjects with high-level (C5-C6) spinal cord injury (SCI) performed five visuo-spatial motor training tasks over 12 sessions (2-3 sessions per week). Subjects controlled a two-dimensional cursor with bilateral simultaneous movements of the shoulders using a non-invasive inertial measurement unit-based body-machine interface. Subjects' upper-body ability was evaluated before the start, in the middle and a day after the completion of training. MR imaging data were acquired before the start and within two days of the completion of training. Subjects learned to use upper-body movements that survived the injury to control the body-machine interface and improved their performance with practice. Motor training increased Manual Muscle Test scores and the isometric force of subjects' shoulders and upper arms. Moreover, motor training increased fractional anisotropy (FA) values in the cingulum of the left hemisphere by 6.02% on average, indicating localized white matter microstructure changes induced by activity-dependent modulation of axon diameter, myelin thickness or axon number. This body-machine interface may serve as a platform to develop a new generation of assistive-rehabilitative devices that promote the use of, and that re-strengthen, the motor and sensory functions that survived the injury.

Understanding biomaterial-tissue interface quality: combined in vitro evaluation

NASA Astrophysics Data System (ADS)

Gasik, Michael

2017-12-01

One of the greatest challenges in the development of new medical products and devices remains in providing maximal patient safety, efficacy and suitability for the purpose. A 'good quality' of the tissue-implant interface is one of the most critical factors for the success of the implant integration. In this paper this challenge is being discussed from the point of view of basic stimuli combination to experimental testing. The focus is in particular on bacterial effects on tissue-implant interaction (for different materials). The demonstration of the experimental evaluation of the tissue-implant interface is for dental abutment with mucosal contact. This shows that testing of the interface quality could be the most relevant in controlled conditions, which mimic as possible the clinical applications, but consider variables being under the control of the evaluator.

Development of a graphical user interface for the global land information system (GLIS)

USGS Publications Warehouse

Alstad, Susan R.; Jackson, David A.

1993-01-01

The process of developing a Motif Graphical User Interface for the Global Land Information System (GLIS) involved incorporating user requirements, in-house visual and functional design requirements, and Open Software Foundation (OSF) Motif style guide standards. Motif user interface windows have been developed using the software to support Motif window functions war written using the C programming language. The GLIS architecture was modified to support multiple servers and remote handlers running the X Window System by forming a network of servers and handlers connected by TCP/IP communications. In April 1993, prior to release the GLIS graphical user interface and system architecture modifications were test by developers and users located at the EROS Data Center and 11 beta test sites across the country.

The Atypical Response Regulator Protein ChxR Has Structural Characteristics and Dimer Interface Interactions That Are Unique within the OmpR/PhoB Subfamily

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hickey, John M.; Lovell, Scott; Battaile, Kevin P.

2013-05-29

Typically as a result of phosphorylation, OmpR/PhoB response regulators form homodimers through a receiver domain as an integral step in transcriptional activation. Phosphorylation stabilizes the ionic and hydrophobic interactions between monomers. Recent studies have shown that some response regulators retain functional activity in the absence of phosphorylation and are termed atypical response regulators. The two currently available receiver domain structures of atypical response regulators are very similar to their phospho-accepting homologs, and their propensity to form homodimers is generally retained. An atypical response regulator, ChxR, from Chlamydia trachomatis, was previously reported to form homodimers; however, the residues critical to thismore » interaction have not been elucidated. We hypothesize that the intra- and intermolecular interactions involved in forming a transcriptionally competent ChxR are distinct from the canonical phosphorylation (activation) paradigm in the OmpR/PhoB response regulator subfamily. To test this hypothesis, structural and functional studies were performed on the receiver domain of ChxR. Two crystal structures of the receiver domain were solved with the recently developed method using triiodo compound I3C. These structures revealed many characteristics unique to OmpR/PhoB subfamily members: typical or atypical. Included was the absence of two {alpha}-helices present in all other OmpR/PhoB response regulators. Functional studies on various dimer interface residues demonstrated that ChxR forms relatively stable homodimers through hydrophobic interactions, and disruption of these can be accomplished with the introduction of a charged residue within the dimer interface. A gel shift study with monomeric ChxR supports that dimerization through the receiver domain is critical for interaction with DNA.« less

Toward FRP-Based Brain-Machine Interfaces—Single-Trial Classification of Fixation-Related Potentials

PubMed Central

Finke, Andrea; Essig, Kai; Marchioro, Giuseppe; Ritter, Helge

2016-01-01

The co-registration of eye tracking and electroencephalography provides a holistic measure of ongoing cognitive processes. Recently, fixation-related potentials have been introduced to quantify the neural activity in such bi-modal recordings. Fixation-related potentials are time-locked to fixation onsets, just like event-related potentials are locked to stimulus onsets. Compared to existing electroencephalography-based brain-machine interfaces that depend on visual stimuli, fixation-related potentials have the advantages that they can be used in free, unconstrained viewing conditions and can also be classified on a single-trial level. Thus, fixation-related potentials have the potential to allow for conceptually different brain-machine interfaces that directly interpret cortical activity related to the visual processing of specific objects. However, existing research has investigated fixation-related potentials only with very restricted and highly unnatural stimuli in simple search tasks while participant’s body movements were restricted. We present a study where we relieved many of these restrictions while retaining some control by using a gaze-contingent visual search task. In our study, participants had to find a target object out of 12 complex and everyday objects presented on a screen while the electrical activity of the brain and eye movements were recorded simultaneously. Our results show that our proposed method for the classification of fixation-related potentials can clearly discriminate between fixations on relevant, non-relevant and background areas. Furthermore, we show that our classification approach generalizes not only to different test sets from the same participant, but also across participants. These results promise to open novel avenues for exploiting fixation-related potentials in electroencephalography-based brain-machine interfaces and thus providing a novel means for intuitive human-machine interaction. PMID:26812487

A brain-spine interface alleviating gait deficits after spinal cord injury in primates.

PubMed

Capogrosso, Marco; Milekovic, Tomislav; Borton, David; Wagner, Fabien; Moraud, Eduardo Martin; Mignardot, Jean-Baptiste; Buse, Nicolas; Gandar, Jerome; Barraud, Quentin; Xing, David; Rey, Elodie; Duis, Simone; Jianzhong, Yang; Ko, Wai Kin D; Li, Qin; Detemple, Peter; Denison, Tim; Micera, Silvestro; Bezard, Erwan; Bloch, Jocelyne; Courtine, Grégoire

2016-11-10

Spinal cord injury disrupts the communication between the brain and the spinal circuits that orchestrate movement. To bypass the lesion, brain-computer interfaces have directly linked cortical activity to electrical stimulation of muscles, and have thus restored grasping abilities after hand paralysis. Theoretically, this strategy could also restore control over leg muscle activity for walking. However, replicating the complex sequence of individual muscle activation patterns underlying natural and adaptive locomotor movements poses formidable conceptual and technological challenges. Recently, it was shown in rats that epidural electrical stimulation of the lumbar spinal cord can reproduce the natural activation of synergistic muscle groups producing locomotion. Here we interface leg motor cortex activity with epidural electrical stimulation protocols to establish a brain-spine interface that alleviated gait deficits after a spinal cord injury in non-human primates. Rhesus monkeys (Macaca mulatta) were implanted with an intracortical microelectrode array in the leg area of the motor cortex and with a spinal cord stimulation system composed of a spatially selective epidural implant and a pulse generator with real-time triggering capabilities. We designed and implemented wireless control systems that linked online neural decoding of extension and flexion motor states with stimulation protocols promoting these movements. These systems allowed the monkeys to behave freely without any restrictions or constraining tethered electronics. After validation of the brain-spine interface in intact (uninjured) monkeys, we performed a unilateral corticospinal tract lesion at the thoracic level. As early as six days post-injury and without prior training of the monkeys, the brain-spine interface restored weight-bearing locomotion of the paralysed leg on a treadmill and overground. The implantable components integrated in the brain-spine interface have all been approved for investigational applications in similar human research, suggesting a practical translational pathway for proof-of-concept studies in people with spinal cord injury.

A Brain–Spinal Interface Alleviating Gait Deficits after Spinal Cord Injury in Primates

PubMed Central

Capogrosso, Marco; Milekovic, Tomislav; Borton, David; Wagner, Fabien; Moraud, Eduardo Martin; Mignardot, Jean-Baptiste; Buse, Nicolas; Gandar, Jerome; Barraud, Quentin; Xing, David; Rey, Elodie; Duis, Simone; Jianzhong, Yang; Ko, Wai Kin D.; Li, Qin; Detemple, Peter; Denison, Tim; Micera, Silvestro; Bezard, Erwan; Bloch, Jocelyne; Courtine, Grégoire

2016-01-01

Spinal cord injury disrupts the communication between the brain and the spinal circuits that orchestrate movement. To bypass the lesion, brain–computer interfaces1–3 have directly linked cortical activity to electrical stimulation of muscles, which have restored grasping abilities after hand paralysis1,4. Theoretically, this strategy could also restore control over leg muscle activity for walking5. However, replicating the complex sequence of individual muscle activation patterns underlying natural and adaptive locomotor movements poses formidable conceptual and technological challenges6,7. Recently, we showed in rats that epidural electrical stimulation of the lumbar spinal cord can reproduce the natural activation of synergistic muscle groups producing locomotion8–10. Here, we interfaced leg motor cortex activity with epidural electrical stimulation protocols to establish a brain–spinal interface that alleviated gait deficits after a spinal cord injury in nonhuman primates. Rhesus monkeys were implanted with an intracortical microelectrode array into the leg area of motor cortex; and a spinal cord stimulation system composed of a spatially selective epidural implant and a pulse generator with real-time triggering capabilities. We designed and implemented wireless control systems that linked online neural decoding of extension and flexion motor states with stimulation protocols promoting these movements. These systems allowed the monkeys to behave freely without any restrictions or constraining tethered electronics. After validation of the brain–spinal interface in intact monkeys, we performed a unilateral corticospinal tract lesion at the thoracic level. As early as six days post-injury and without prior training of the monkeys, the brain–spinal interface restored weight-bearing locomotion of the paralyzed leg on a treadmill and overground. The implantable components integrated in the brain–spinal interface have all been approved for investigational applications in similar human research, suggesting a practical translational pathway for proof-of-concept studies in people with spinal cord injury. PMID:27830790

The decisive effect of interface states on the photocatalytic activity of the silver(I) oxide/titanium dioxide heterojunction.

PubMed

Lei, Yanqiang; Lu, Xiaoqing

2017-04-15

A one-step hydrothermal method was adopted to synthesize the Ag 2 O/TiO 2 nanoheterojunction. Its photocatalytic activity was evaluated by degrading methylene blue (MB) aqueous solution under UV and visible light. The MB degradation results showed that the Ag 2 O/TiO 2 nanoheterojunction enhances the photocatalytic activity under UV irradiation rather than visible light. X-ray photoelectron spectroscopy (XPS) was performed to detect the electronic structure at the interface of Ag 2 O and TiO 2 . The XPS results confirmed that the electronic band structure of the nanoheterojunction was determined by the interface states between the Ag 2 O and TiO 2 interface. Thus, the photocatalytic enhancement mechanism can be ascribed to the creation of an additional potential barrier in the conduction band between Ag 2 O and TiO 2 , which facilitates the transport of holes from TiO 2 to Ag 2 O but inhibits the flow of electrons in the reverse direction unless sufficient potential energy is provided to overcome the additional barrier. Our results have provided a new insight on the role of interface states between the p-n nanojunction in the photocatalytic activity. Copyright © 2017 Elsevier Inc. All rights reserved.

Allosteric Inhibition of Bcr-Abl Kinase by High Affinity Monobody Inhibitors Directed to the Src Homology 2 (SH2)-Kinase Interface.

PubMed

Wojcik, John; Lamontanara, Allan Joaquim; Grabe, Grzegorz; Koide, Akiko; Akin, Louesa; Gerig, Barbara; Hantschel, Oliver; Koide, Shohei

2016-04-15

Bcr-Abl is a constitutively active kinase that causes chronic myelogenous leukemia. We have shown that a tandem fusion of two designed binding proteins, termed monobodies, directed to the interaction interface between the Src homology 2 (SH2) and kinase domains and to the phosphotyrosine-binding site of the SH2 domain, respectively, inhibits the Bcr-Abl kinase activity. Because the latter monobody inhibits processive phosphorylation by Bcr-Abl and the SH2-kinase interface is occluded in the active kinase, it remained undetermined whether targeting the SH2-kinase interface alone was sufficient for Bcr-Abl inhibition. To address this question, we generated new, higher affinity monobodies with single nanomolar KD values targeting the kinase-binding surface of SH2. Structural and mutagenesis studies revealed the molecular underpinnings of the monobody-SH2 interactions. Importantly, the new monobodies inhibited Bcr-Abl kinase activity in vitro and in cells, and they potently induced cell death in chronic myelogenous leukemia cell lines. This work provides strong evidence for the SH2-kinase interface as a pharmacologically tractable site for allosteric inhibition of Bcr-Abl. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

A four-dimensional virtual hand brain-machine interface using active dimension selection

NASA Astrophysics Data System (ADS)

Rouse, Adam G.

2016-06-01

Objective. Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. Approach. ADS utilizes a two stage decoder by using neural signals to both (i) select an active dimension being controlled and (ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Main results. Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits s-1 for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. Significance. ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand.

A four-dimensional virtual hand brain-machine interface using active dimension selection

PubMed Central

Rouse, Adam G.

2018-01-01

Objective Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. Approach ADS utilizes a two stage decoder by using neural signals to both i) select an active dimension being controlled and ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Main Results Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits/s for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. Significance ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand. PMID:27171896

Tailoring the electrode-electrolyte interface of Solid Oxide Fuel Cells (SOFC) by laser micro-patterning to improve their electrochemical performance

NASA Astrophysics Data System (ADS)

Cebollero, J. A.; Lahoz, R.; Laguna-Bercero, M. A.; Larrea, A.

2017-08-01

Cathode activation polarisation is one of the main contributions to the losses of a Solid Oxide Fuel Cell. To reduce this loss we use a pulsed laser to modify the surface of yttria stabilized zirconia (YSZ) electrolytes to make a corrugated micro-patterning in the mesoscale. The beam of the laser source, 5 ns pulse width and emitting at λ = 532 nm (green region), is computer-controlled to engrave the selected micro-pattern on the electrolyte surface. Several laser scanning procedures and geometries have been tested. Finally, we engrave a square array with 28 μm of lattice parameter and 7 μm in depth on YSZ plates. With these plates we prepare LSM-YSZ/YSZ/LSM-YSZ symmetrical cells (LSM: La1-xSrxMnO3) and determine their activation polarisation by Electrochemical Impedance Spectroscopy (EIS). To get good electrode-electrolyte contact after sintering it is necessary to use pressure-assisted sintering with low loads (about 5 kPa), which do not modify the electrode microstructure. The decrease in polarisation with respect to an unprocessed cell is about 30%. EIS analysis confirms that the reason for this decrease is an improvement in the activation processes at the electrode-electrolyte interface.

Immunochromatographic diagnostic test analysis using Google Glass.

PubMed

Feng, Steve; Caire, Romain; Cortazar, Bingen; Turan, Mehmet; Wong, Andrew; Ozcan, Aydogan

2014-03-25

We demonstrate a Google Glass-based rapid diagnostic test (RDT) reader platform capable of qualitative and quantitative measurements of various lateral flow immunochromatographic assays and similar biomedical diagnostics tests. Using a custom-written Glass application and without any external hardware attachments, one or more RDTs labeled with Quick Response (QR) code identifiers are simultaneously imaged using the built-in camera of the Google Glass that is based on a hands-free and voice-controlled interface and digitally transmitted to a server for digital processing. The acquired JPEG images are automatically processed to locate all the RDTs and, for each RDT, to produce a quantitative diagnostic result, which is returned to the Google Glass (i.e., the user) and also stored on a central server along with the RDT image, QR code, and other related information (e.g., demographic data). The same server also provides a dynamic spatiotemporal map and real-time statistics for uploaded RDT results accessible through Internet browsers. We tested this Google Glass-based diagnostic platform using qualitative (i.e., yes/no) human immunodeficiency virus (HIV) and quantitative prostate-specific antigen (PSA) tests. For the quantitative RDTs, we measured activated tests at various concentrations ranging from 0 to 200 ng/mL for free and total PSA. This wearable RDT reader platform running on Google Glass combines a hands-free sensing and image capture interface with powerful servers running our custom image processing codes, and it can be quite useful for real-time spatiotemporal tracking of various diseases and personal medical conditions, providing a valuable tool for epidemiology and mobile health.

Immunochromatographic Diagnostic Test Analysis Using Google Glass

PubMed Central

2014-01-01

We demonstrate a Google Glass-based rapid diagnostic test (RDT) reader platform capable of qualitative and quantitative measurements of various lateral flow immunochromatographic assays and similar biomedical diagnostics tests. Using a custom-written Glass application and without any external hardware attachments, one or more RDTs labeled with Quick Response (QR) code identifiers are simultaneously imaged using the built-in camera of the Google Glass that is based on a hands-free and voice-controlled interface and digitally transmitted to a server for digital processing. The acquired JPEG images are automatically processed to locate all the RDTs and, for each RDT, to produce a quantitative diagnostic result, which is returned to the Google Glass (i.e., the user) and also stored on a central server along with the RDT image, QR code, and other related information (e.g., demographic data). The same server also provides a dynamic spatiotemporal map and real-time statistics for uploaded RDT results accessible through Internet browsers. We tested this Google Glass-based diagnostic platform using qualitative (i.e., yes/no) human immunodeficiency virus (HIV) and quantitative prostate-specific antigen (PSA) tests. For the quantitative RDTs, we measured activated tests at various concentrations ranging from 0 to 200 ng/mL for free and total PSA. This wearable RDT reader platform running on Google Glass combines a hands-free sensing and image capture interface with powerful servers running our custom image processing codes, and it can be quite useful for real-time spatiotemporal tracking of various diseases and personal medical conditions, providing a valuable tool for epidemiology and mobile health. PMID:24571349

Development and testing of an active boring bar for increased chatter immunity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redmond, J.; Barney, P.

Recent advances in smart materials have renewed interest in the development of improved manufacturing processes featuring sensing, processing, and active control. In particular, vibration suppression in metal cutting has received much attention because of its potential for enhancing part quality while reducing the time and cost of production. Although active tool clamps have been recently demonstrated, they are often accompanied by interfacing issues that limit their applicability to specific machines. Under the auspices of the Laboratory Directed Research and Development program, the project titled {open_quotes}Smart Cutting Tools for Precision Manufacturing{close_quotes} developed an alternative approach to active vibration control in machining.more » Using the boring process as a vehicle for exploration, a commercially available tool was modified to incorporate PZT stack actuators for active suppression of its bending modes. Since the modified tool requires no specialized mounting hardware, it can be readily mounted on many machines. Cutting tests conducted on a horizontal lathe fitted with a hardened steel workpiece verify that the actively damped boring bar yields significant vibration reduction and improved surface finishes as compared to an unmodified tool.« less

Virtual Sensor Test Instrumentation

NASA Technical Reports Server (NTRS)

Wang, Roy

2011-01-01

Virtual Sensor Test Instrumentation is based on the concept of smart sensor technology for testing with intelligence needed to perform sell-diagnosis of health, and to participate in a hierarchy of health determination at sensor, process, and system levels. A virtual sensor test instrumentation consists of five elements: (1) a common sensor interface, (2) microprocessor, (3) wireless interface, (4) signal conditioning and ADC/DAC (analog-to-digital conversion/ digital-to-analog conversion), and (5) onboard EEPROM (electrically erasable programmable read-only memory) for metadata storage and executable software to create powerful, scalable, reconfigurable, and reliable embedded and distributed test instruments. In order to maximize the efficient data conversion through the smart sensor node, plug-and-play functionality is required to interface with traditional sensors to enhance their identity and capabilities for data processing and communications. Virtual sensor test instrumentation can be accessible wirelessly via a Network Capable Application Processor (NCAP) or a Smart Transducer Interlace Module (STIM) that may be managed under real-time rule engines for mission-critical applications. The transducer senses the physical quantity being measured and converts it into an electrical signal. The signal is fed to an A/D converter, and is ready for use by the processor to execute functional transformation based on the sensor characteristics stored in a Transducer Electronic Data Sheet (TEDS). Virtual sensor test instrumentation is built upon an open-system architecture with standardized protocol modules/stacks to interface with industry standards and commonly used software. One major benefit for deploying the virtual sensor test instrumentation is the ability, through a plug-and-play common interface, to convert raw sensor data in either analog or digital form, to an IEEE 1451 standard-based smart sensor, which has instructions to program sensors for a wide variety of functions. The sensor data is processed in a distributed fashion across the network, providing a large pool of resources in real time to meet stringent latency requirements.

APRN Usability Testing of a Tailored Computer-Mediated Health Communication Program

PubMed Central

Lin, Carolyn A.; Neafsey, Patricia J.; Anderson, Elizabeth

2010-01-01

This study tested the usability of a touch-screen enabled “Personal Education Program” (PEP) with Advanced Practice Registered Nurses (APRN). The PEP is designed to enhance medication adherence and reduce adverse self-medication behaviors in older adults with hypertension. An iterative research process was employed, which involved the use of: (1) pre-trial focus groups to guide the design of system information architecture, (2) two different cycles of think-aloud trials to test the software interface, and (3) post-trial focus groups to gather feedback on the think-aloud studies. Results from this iterative usability testing process were utilized to systematically modify and improve the three PEP prototype versions—the pilot, Prototype-1 and Prototype-2. Findings contrasting the two separate think-aloud trials showed that APRN users rated the PEP system usability, system information and system-use satisfaction at a moderately high level between trials. In addition, errors using the interface were reduced by 76 percent and the interface time was reduced by 18.5 percent between the two trials. The usability testing processes employed in this study ensured an interface design adapted to APRNs' needs and preferences to allow them to effectively utilize the computer-mediated health-communication technology in a clinical setting. PMID:19940619

Team Oriented Robotic Exploration Task on Scorpion and K9 Platforms

NASA Technical Reports Server (NTRS)

Kirchner, Frank

2003-01-01

This final report describes the achievements that have been made in the project over the complete period of performance. The technical progress highlights the different areas of work in terms of Progress in Mechatronics, Sensor integration, Software Development. User Interfaces, Behavior Development and Experimental Results and System Testing. The different areas are: Mechatronics, Sensor integration, Software development, Experimental results and Basic System Testing, Behaviors Development and Advanced System Testing, User Interface and Wireless Communication.

Data-Logger Interface And Test Controller

NASA Technical Reports Server (NTRS)

Burch, Donnie R.

1995-01-01

Data-logger interface and test controller developed to enable automation of tests in conjunction with data-acquisition functions performed by data loggers that have output-switching capabilities. Includes relay logic circuits that remain deenergized until out-of-tolerance condition on any data channel discovered. Designed to be connected to Fluke model 2286A (or equivalent) data-logger system, which features 3 control channels with 6 data inputs per channel. Includes elapsed-time counter that keeps track of power outages.

NREL’s Controllable Grid Interface Saves Time and Resources, Improves Reliability of Renewable Energy Technologies; NREL (National Renewable Energy Laboratory)

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

The National Renewable Energy Laboratory's (NREL) controllable grid interface (CGI) test system at the National Wind Technology Center (NWTC) is one of two user facilities at NREL capable of testing and analyzing the integration of megawatt-scale renewable energy systems. The CGI specializes in testing of multimegawatt-scale wind and photovoltaic (PV) technologies as well as energy storage devices, transformers, control and protection equipment at medium-voltage levels, allowing the determination of the grid impacts of the tested technology.

Embedded System for Prosthetic Control Using Implanted Neuromuscular Interfaces Accessed Via an Osseointegrated Implant.

PubMed

Mastinu, Enzo; Doguet, Pascal; Botquin, Yohan; Hakansson, Bo; Ortiz-Catalan, Max

2017-08-01

Despite the technological progress in robotics achieved in the last decades, prosthetic limbs still lack functionality, reliability, and comfort. Recently, an implanted neuromusculoskeletal interface built upon osseointegration was developed and tested in humans, namely the Osseointegrated Human-Machine Gateway. Here, we present an embedded system to exploit the advantages of this technology. Our artificial limb controller allows for bioelectric signals acquisition, processing, decoding of motor intent, prosthetic control, and sensory feedback. It includes a neurostimulator to provide direct neural feedback based on sensory information. The system was validated using real-time tasks characterization, power consumption evaluation, and myoelectric pattern recognition performance. Functionality was proven in a first pilot patient from whom results of daily usage were obtained. The system was designed to be reliably used in activities of daily living, as well as a research platform to monitor prosthesis usage and training, machine-learning-based control algorithms, and neural stimulation paradigms.

DSN Resource Scheduling

NASA Technical Reports Server (NTRS)

Wang, Yeou-Fang; Baldwin, John

2007-01-01

TIGRAS is client-side software, which provides tracking-station equipment planning, allocation, and scheduling services to the DSMS (Deep Space Mission System). TIGRAS provides functions for schedulers to coordinate the DSN (Deep Space Network) antenna usage time and to resolve the resource usage conflicts among tracking passes, antenna calibrations, maintenance, and system testing activities. TIGRAS provides a fully integrated multi-pane graphical user interface for all scheduling operations. This is a great improvement over the legacy VAX VMS command line user interface. TIGRAS has the capability to handle all DSN resource scheduling aspects from long-range to real time. TIGRAS assists NASA mission operations for DSN tracking of station equipment resource request processes from long-range load forecasts (ten years or longer), to midrange, short-range, and real-time (less than one week) emergency tracking plan changes. TIGRAS can be operated by NASA mission operations worldwide to make schedule requests for the DSN station equipment.

Evolving from Planning and Scheduling to Real-Time Operations Support: Design Challenges

NASA Technical Reports Server (NTRS)

Marquez, Jessica J.; Ludowise, Melissa; McCurdy, Michael; Li, Jack

2010-01-01

Versions of Scheduling and Planning Interface for Exploration (SPIFe) have supported a variety of mission operations across NASA. This software tool has evolved and matured over several years, assisting planners who develop intricate schedules. While initially conceived for surface Mars missions, SPIFe has been deployed in other domains, where people rather than robotic explorers, execute plans. As a result, a diverse set of end-users has compelled growth in a new direction: supporting real-time operations. This paper describes the new needs and challenges that accompany this development. Among the key features that have been built for SPIFe are current time indicators integrated into the interface and timeline, as well as other plan attributes that enable execution of scheduled activities. Field tests include mission support for the Lunar CRater Observation and Sensing Satellite (LCROSS), NASA Extreme Environment Mission Operations (NEEMO) and Desert Research and Technology Studies (DRATS) campaigns.

Active Microelectronic Neurosensor Arrays for Implantable Brain Communication Interfaces

PubMed Central

Song, Y.-K.; Borton, D. A.; Park, S.; Patterson, W. R.; Bull, C. W.; Laiwalla, F.; Mislow, J.; Simeral, J. D.; Donoghue, J. P.; Nurmikko, A. V.

2010-01-01

We have built a wireless implantable microelectronic device for transmitting cortical signals transcutaneously. The device is aimed at interfacing a microelectrode array cortical to an external computer for neural control applications. Our implantable microsystem enables presently 16-channel broadband neural recording in a non-human primate brain by converting these signals to a digital stream of infrared light pulses for transmission through the skin. The implantable unit employs a flexible polymer substrate onto which we have integrated ultra-low power amplification with analog multiplexing, an analog-to-digital converter, a low power digital controller chip, and infrared telemetry. The scalable 16-channel microsystem can employ any of several modalities of power supply, including via radio frequency by induction, or infrared light via a photovoltaic converter. As of today, the implant has been tested as a sub-chronic unit in non-human primates (~ 1 month), yielding robust spike and broadband neural data on all available channels. PMID:19502132

Sampling and Control Circuit Board for an Inertial Measurement Unit

NASA Technical Reports Server (NTRS)

Chelmins, David; Powis, Rick

2012-01-01

Spacesuit navigation is one component of NASA s efforts to return humans to the Moon. Studies performed at the NASA Glenn Research Center (GRC) considered various navigation technologies and filtering approaches to enable navigation on the lunar surface. As part of this effort, microelectromechanical systems (MEMS) inertial measurement units (IMUs) were studied to determine if they could supplement a radiometric infrastructure. MEMS IMUs were included in the Lunar Extra-Vehicular Activity Crewmember Location Determination System (LECLDS) testbed during NASA s annual Desert Research and Technology Studies (D-RATS) event in 2009 and 2010. The testbed included one IMU in 2009 and three IMUs in 2010, along with a custom circuit board interfacing between the navigation processor and each IMU. The board was revised for the 2010 test, and this paper documents the design details of this latest revision of the interface circuit board and firmware.

[Neurophysiological Foundations and Practical Realizations of the Brain-Machine Interfaces the Technology in Neurological Rehabilitation].

PubMed

Kaplan, A Ya

2016-01-01

Technology brain-computer interface (BCI) based on the registration and interpretation of EEG has recently become one of the most popular developments in neuroscience and psychophysiology. This is due not only to the intended future use of these technologies in many areas of practical human activity, but also to the fact that IMC--is a completely new paradigm in psychophysiology, allowing test hypotheses about the possibilities of the human brain to the development of skills of interaction with the outside world without the mediation of the motor system, i.e. only with the help of voluntary modulation of EEG generators. This paper examines the theoretical and experimental basis, the current state and prospects of development of training, communicational and assisting complexes based on BCI to control them without muscular effort on the basis of mental commands detected in the EEG of patients with severely impaired speech and motor system.

Optical to optical interface device

NASA Technical Reports Server (NTRS)

Oliver, D. S.; Vohl, P.; Nisenson, P.

1972-01-01

The development, fabrication, and testing of a preliminary model of an optical-to-optical (noncoherent-to-coherent) interface device for use in coherent optical parallel processing systems are described. The developed device demonstrates a capability for accepting as an input a scene illuminated by a noncoherent radiation source and providing as an output a coherent light beam spatially modulated to represent the original noncoherent scene. The converter device developed under this contract employs a Pockels readout optical modulator (PROM). This is a photosensitive electro-optic element which can sense and electrostatically store optical images. The stored images can be simultaneously or subsequently readout optically by utilizing the electrostatic storage pattern to control an electro-optic light modulating property of the PROM. The readout process is parallel as no scanning mechanism is required. The PROM provides the functions of optical image sensing, modulation, and storage in a single active material.

Development and Feasibility Testing of a Smartphone Intervention to Improve Adherence to Antipsychotic Medications

PubMed Central

Kreyenbuhl, Julie; Record, Elizabeth J.; Himelhoch, Seth; Charlotte, Melanie; Palmer-Bacon, Jessica; Dixon, Lisa B.; Medoff, Deborah R.; Li, Lan

2017-01-01

Approximately 60% of individuals with schizophrenia do not take their antipsychotic medications as prescribed, and nonadherence is associated with exacerbation of psychotic symptoms, increased hospital and emergency room use, and increased healthcare costs. Behavioral-tailoring strategies that incorporate medication taking into the daily routine and use environmental supports have shown promise as adherence-enhancing interventions. Informed by the Information-Motivation-Behavioral (IMB) Skills Model and using the iterative process of user-centered design, we collaborated with individuals with schizophrenia and psychiatrists to develop an interactive smartphone application and web-based clinician interface, MedActive, for improving adherence to oral antipsychotic treatment. MedActive facilitates the active involvement of individuals with schizophrenia in managing their antipsychotic medication regimen by providing automated reminders for medication administration and tailored motivational feedback to encourage adherence, and by displaying user-friendly results of daily ecological momentary assessments (EMAs) of medication adherence, positive psychotic symptoms, and medication side effects for individuals and their psychiatrists. In a 2-week open trial completed by 7 individuals with schizophrenia and their psychiatrists, MedActive was determined to be both feasible and acceptable, with patient participants responding to 80% of all scheduled EMAs and providing positive evaluations of their use of the application. Psychiatrist participants were interested in viewing the information provided on the MedActive clinician interface, but cited practical barriers to regularly accessing it and integrating into their daily practice. PMID:27454213

A specific, transmembrane interface regulates fibroblast activation protein (FAP) homodimerization, trafficking and exopeptidase activity.

PubMed

Wonganu, Benjamaporn; Berger, Bryan W

2016-08-01

Fibroblast activation protein (FAP) is a cell-surface serine protease which promotes invasiveness of certain epithelial cancers and is therefore a potential target for cancer drug development and delivery. Unlike dipeptidyl peptidase IV (DPPIV), FAP exhibits prolyl endopeptidase activity and is active as a homodimer with specificity for type I collagen. The mechanism that regulates FAP homodimerization and its relation to prolyl endopeptidase activity is not completely understood. Here, we investigate key residues in the FAP TM domain that may be significant for FAP homodimerization. Mutations to predicted TM interfacial residues (G10L, S14L, and A18L) comprising a small-X3-small motif reduced FAP TM-CYTO dimerization relative to wild type as measured using the AraTM assay, whereas predicted off-interface residues showed no significant change from wild type. The results implied that the predicted small-X3-small dimer interface affect stabilization of FAP TM-CYTO homodimerization. Compared with FAPwild-type, the interfacial TM residue G10L significantly decreased FAP endopeptidase activity more than 25%, and also reduced cell-surface versus intracellular expression relative to other interfacial residues S14L and A18L. Thus, our results suggest FAP dimerization is important for both trafficking and protease activity, and is dependent on a specific TM interface. Copyright © 2016 Elsevier B.V. All rights reserved.

Vertically aligned carbon nanofiber as nano-neuron interface for monitoring neural function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ericson, Milton Nance; McKnight, Timothy E; Melechko, Anatoli Vasilievich

2012-01-01

Neural chips, which are capable of simultaneous, multi-site neural recording and stimulation, have been used to detect and modulate neural activity for almost 30 years. As a neural interface, neural chips provide dynamic functional information for neural decoding and neural control. By improving sensitivity and spatial resolution, nano-scale electrodes may revolutionize neural detection and modulation at cellular and molecular levels as nano-neuron interfaces. We developed a carbon-nanofiber neural chip with lithographically defined arrays of vertically aligned carbon nanofiber electrodes and demonstrated its capability of both stimulating and monitoring electrophysiological signals from brain tissues in vitro and monitoring dynamic information ofmore » neuroplasticity. This novel nano-neuron interface can potentially serve as a precise, informative, biocompatible, and dual-mode neural interface for monitoring of both neuroelectrical and neurochemical activity at the single cell level and even inside the cell.« less

Testing framework for embedded languages

NASA Astrophysics Data System (ADS)

Leskó, Dániel; Tejfel, Máté

2012-09-01

Embedding a new programming language into an existing one is a widely used technique, because it fastens the development process and gives a part of a language infrastructure for free (e.g. lexical, syntactical analyzers). In this paper we are presenting a new advantage of this development approach regarding to adding testing support for these new languages. Tool support for testing is a crucial point for a newly designed programming language. It could be done in the hard way by creating a testing tool from scratch, or we could try to reuse existing testing tools by extending them with an interface to our new language. The second approach requires less work, and also it fits very well for the embedded approach. The problem is that the creation of such interfaces is not straightforward at all, because the existing testing tools were mostly not designed to be extendable and to be able to deal with new languages. This paper presents an extendable and modular model of a testing framework, in which the most basic design decision was to keep the - previously mentioned - interface creation simple and straightforward. Other important aspects of our model are the test data generation, the oracle problem and the customizability of the whole testing phase.

A Test for Characterizing Delamination Migration in Carbon/Epoxy Tape Laminates

NASA Technical Reports Server (NTRS)

Ratcliffe, James G.; Czabaj, Michael W.; O'Brien, Thomas K.

2013-01-01

A new test method is presented for the purpose of investigating migration of a delamination between neighboring ply interfaces in fiber-reinforced, polymer matrix tape laminates. The test is a single cantilever beam configuration consisting of a cross-ply laminate with a polytetrafluoroethylene insert implanted at the mid-plane and spanning part way along the length of the specimen. The insert is located between a 0- degree ply (specimen length direction) and a stack of four 90-degree plies (specimen width direction). The specimen is clamped at both ends onto a rigid baseplate and is loaded on its upper surface via a piano hinge. Tests were conducted with the load-application point located on the intact portion of the specimen in order to initiate delamination growth onset followed by migration of the delamination to a neighboring 90/0 ply interface by kinking through the 90-degree ply stack. Varying this position was found to affect the distance relative to the load-application point at which migration initiated. In each specimen, migration initiated by a gradual transition of the delamination at the 0/90 interface into the 90-degree ply stack. In contrast, transition of the kinked crack into the 90/0 interface was sudden. Fractography of the specimens indicated that delamination prior to migration was generally mixed mode-I/II. Inspection of the kink surface revealed mode-I fracture. In general, use of this test allows for the observation of the growth of a delamination followed by migration of the delamination to another ply interface, and should thus provide a means for validating analyses aimed at simulating migration.

Light-induced spatial control of pH-jump reaction at smart gel interface.

PubMed

Techawanitchai, Prapatsorn; Ebara, Mitsuhiro; Idota, Naokazu; Aoyagi, Takao

2012-11-01

We proposed here a 'smart' control of an interface movement of proton diffusion in temperature- and pH-responsive hydrogels using a light-induced spatial pH-jump reaction. A photoinitiated proton-releasing reaction of o-nitrobenzaldehyde (NBA) was integrated into poly(N-isopropylacrylamide-o-2-carboxyisopropylacrylamide) (P(NIPAAm-co-CIPAAm)) hydrogels. NBA-integrated hydrogels demonstrated quick release of proton upon UV irradiation, allowing the pH inside the gel to decrease below the pK(a) of P(NIPAAm-co-CIPAAm) within a minute. The NBA-integrated gel was shown to shrink rapidly upon UV irradiation without polymer "skin layer" formation due to a uniform decrease of pH inside the gel. Spatial control of gel shrinking was also created by irradiating UV light to a limited region of the gel through a photomask. The interface of proton diffusion ("active interface") gradually moved toward non-illuminated area. The apparent position of "active interface", however, did not change remarkably above the LCST, while protons continuously diffused outward direction. This is because the "active interface" also moved inward direction as gel shrank above the LCST. As a result, slow movement of the apparent interface was observed. The NBA-integrated gel was also successfully employed for the controlled release of an entrapped dextran in a light controlled manner. This system is highly promising as smart platforms for triggered and programmed transportation of drugs. Copyright © 2011 Elsevier B.V. All rights reserved.

MiRTE: Mixed Reality Triage and Evacuation game for Mass Casualty information systems design, testing and training.

PubMed

Yu, Xunyi; Ganz, Aura

2011-01-01

In this paper we introduce a Mixed Reality Triage and Evacuation game, MiRTE, that is used in the development, testing and training of Mass Casualty Incident (MCI) information systems for first responders. Using the Source game engine from Valve software, MiRTE creates immersive virtual environments to simulate various incident scenarios, and enables interactions between multiple players/first responders. What distinguishes it from a pure computer simulation game is that it can interface with external mass casualty incident management systems, such as DIORAMA. The game will enable system developers to specify technical requirements of underlying technology, and test different alternatives of design. After the information system hardware and software are completed, the game can simulate various algorithms such as localization technologies, and interface with an actual user interface on PCs and Smartphones. We implemented and tested the game with the DIORAMA system.

Spontaneous assembly of HSP90 inhibitors at water/octanol interface: A molecular dynamics simulation study

NASA Astrophysics Data System (ADS)

Zolghadr, Amin Reza; Boroomand, Samaneh

2017-02-01

Drug absorption at an acceptable dose depends on the pair of solubility and permeability. There are many potent therapeutics that are not active in vivo, presumably due to the lack of capability to cross the cell membrane. Molecular dynamics simulation of radicicol, diol-radicicol, cyclopropane-radicicol and 17-DMAG were performed at water/octanol interface to suggest interfacial activity as a physico-chemical characteristic of these heat shock protein 90 (HSP90) inhibitors. We have observed that orally active HSP90 inhibitors form aggregates at the water/octanol and DPPC-lipid/water interfaces by starting from an initial configuration with HSP90 inhibitors embedded in the water matrix.

The Work-Study Interface: Similarities and Differences between Ethnic Minority and Ethnic Majority Students

ERIC Educational Resources Information Center

Meeuwisse, Marieke; de Meijer, Lonneke A.; Born, Marise Ph.; Severiens, Sabine E.

2017-01-01

Given the poorer academic outcomes of non-Western ethnic minority students compared to ethnic majority students, we investigated whether differences exist in work-study interface between ethnic groups. We tested a work-study interface model, in which the work-related factors work-study congruence, job control, job demands, work hours, job…

Design of a Computer-Controlled, Random-Access Slide Projector Interface. Final Report (April 1974 - November 1974).

ERIC Educational Resources Information Center

Kirby, Paul J.; And Others

The design, development, test, and evaluation of an electronic hardware device interfacing a commercially available slide projector with a plasma panel computer terminal is reported. The interface device allows an instructional computer program to select slides for viewing based upon the lesson student situation parameters of the instructional…

Development of a Math Input Interface with Flick Operation for Mobile Devices

ERIC Educational Resources Information Center

Nakamura, Yasuyuki; Nakahara, Takahiro

2016-01-01

Developing online test environments for e-learning for mobile devices will be useful to increase drill practice opportunities. In order to provide a drill practice environment for calculus using an online math test system, such as STACK, we develop a flickable math input interface that can be easily used on mobile devices. The number of taps…

Design and Fabrication of Cryostat Interface and Electronics for High Performance Antimatter Trap (HI-PAT)

NASA Technical Reports Server (NTRS)

Smith, Gerald A.

1999-01-01

Included in Appendix I to this report is a complete set of design and assembly schematics for the high vacuum inner trap assembly, cryostat interfaces and electronic components for the MSFC HI-PAT. Also included in the final report are summaries of vacuum tests, and electronic tests performed upon completion of the assembly.

Nondestructive testing of delaminated interfaces between two materials using electromagnetic interrogation

NASA Astrophysics Data System (ADS)

Cakoni, Fioralba; de Teresa, Irene; Monk, Peter

2018-06-01

We consider the problem of detecting whether two materials that should be in contact have separated or delaminated using electromagnetic radiation. The interface damage is modeled as a thin opening between two materials of different electromagnetic properties. To derive a reconstruction algorithm that focuses on testing for the delamination at the interface between the two materials, we use the approximate asymptotic model for the forward problem derived in de Teresa (2017 PhD Thesis University of Delaware). In this model, the differential equations in the small opening are replaced by approximate transmission conditions for the electromagnetic fields across the interface. We also assume that the undamaged or background state is known and it is desired to find where the delamination has opened. We adapt the linear sampling method to this configuration in order to locate the damaged part of the interface from a knowledge of the scattered field and the undamaged configuration, but without needing to know the electromagnetic properties of the opening. Numerical examples are presented to validate our algorithm.

Disruption of PH–kinase domain interactions leads to oncogenic activation of AKT in human cancers

PubMed Central

Parikh, Chaitali; Janakiraman, Vasantharajan; Wu, Wen-I; Foo, Catherine K.; Kljavin, Noelyn M.; Chaudhuri, Subhra; Stawiski, Eric; Lee, Brian; Lin, Jie; Li, Hong; Lorenzo, Maria N.; Yuan, Wenlin; Guillory, Joseph; Jackson, Marlena; Rondon, Jesus; Franke, Yvonne; Bowman, Krista K.; Sagolla, Meredith; Stinson, Jeremy; Wu, Thomas D.; Wu, Jiansheng; Stokoe, David; Stern, Howard M.; Brandhuber, Barbara J.; Lin, Kui; Skelton, Nicholas J.; Seshagiri, Somasekar

2012-01-01

The protein kinase v-akt murine thymoma viral oncogene homolog (AKT), a key regulator of cell survival and proliferation, is frequently hyperactivated in human cancers. Intramolecular pleckstrin homology (PH) domain–kinase domain (KD) interactions are important in maintaining AKT in an inactive state. AKT activation proceeds after a conformational change that dislodges the PH from the KD. To understand these autoinhibitory interactions, we generated mutations at the PH–KD interface and found that most of them lead to constitutive activation of AKT. Such mutations are likely another mechanism by which activation may occur in human cancers and other diseases. In support of this likelihood, we found somatic mutations in AKT1 at the PH–KD interface that have not been previously described in human cancers. Furthermore, we show that the AKT1 somatic mutants are constitutively active, leading to oncogenic signaling. Additionally, our studies show that the AKT1 mutants are not effectively inhibited by allosteric AKT inhibitors, consistent with the requirement for an intact PH–KD interface for allosteric inhibition. These results have important implications for therapeutic intervention in patients with AKT mutations at the PH–KD interface. PMID:23134728

Deep sub-seafloor prokaryotes stimulated at interfaces over geological time.

PubMed

Parkes, R John; Webster, Gordon; Cragg, Barry A; Weightman, Andrew J; Newberry, Carole J; Ferdelman, Timothy G; Kallmeyer, Jens; Jørgensen, Bo B; Aiello, Ivano W; Fry, John C

2005-07-21

The sub-seafloor biosphere is the largest prokaryotic habitat on Earth but also a habitat with the lowest metabolic rates. Modelled activity rates are very low, indicating that most prokaryotes may be inactive or have extraordinarily slow metabolism. Here we present results from two Pacific Ocean sites, margin and open ocean, both of which have deep, subsurface stimulation of prokaryotic processes associated with geochemical and/or sedimentary interfaces. At 90 m depth in the margin site, stimulation was such that prokaryote numbers were higher (about 13-fold) and activity rates higher than or similar to near-surface values. Analysis of high-molecular-mass DNA confirmed the presence of viable prokaryotes and showed changes in biodiversity with depth that were coupled to geochemistry, including a marked community change at the 90-m interface. At the open ocean site, increases in numbers of prokaryotes at depth were more restricted but also corresponded to increased activity; however, this time they were associated with repeating layers of diatom-rich sediments (about 9 Myr old). These results show that deep sedimentary prokaryotes can have high activity, have changing diversity associated with interfaces and are active over geological timescales.

Testing of Environmental Satellite Bus-Instrument Interfaces Using Engineering Models

NASA Technical Reports Server (NTRS)

Gagnier, Don; Hayner, Rick; Roza, Michael; Nosek, Thomas; Razzaghi, Andrea

2004-01-01

This paper discusses the formulation and execution of a laboratory test of the electrical interfaces between multiple atmospheric science instruments and the spacecraft bus that carries them. The testing, performed in 2002, used engineering models of the instruments that will be flown on the Aura s p a c m and of the Aura spacecraft bus electronics. Aura is one of NASA's Earth Observing System @OS) Program missions managed by the Goddard Space Flight Center. The test was designed to evaluate the complex interfaces in the spacecraft and instrument command and data handling (C&DH) subsystems prior to integration of the complete flight instruments on the spacecraft. A problem discovered during (and not before) the flight hardware integration phase can cause significant cost and schedule impacts. The testing successfully surfaced problems and led to their resolution before the full-up integration phase, saving significant cost and schedule time. This approach could be used on future environmental satellite programs involving multiple, complex scientific instruments being integrated onto a bus.

Mini-interfacial fracture toughness as a new validated enamel-bonding effectiveness test.

PubMed

Pongprueksa, Pong; De Munck, Jan; Barreto, Bruno C; Karunratanakul, Kavin; Van Meerbeek, Bart

2016-09-01

Today׳s most commonly applied bonding effectiveness tests are criticized for their high variability and low reliability, the latter in particular with regard to measuring the actual strength of the adhesive interface. in continuation of previous research conducted at dentin, we hereby aimed to validate the novel mini-interfacial fracture toughness (mini-iFT) test on its applicability to assess bonding effectiveness of contemporary adhesives when bonded to enamel. The 3-step etch&rinse (E&R) adhesive OptiBond FL (Kerr), the 2-step self-etch (SE) adhesive Clearfil SE Bond (Kuraray Noritake) and the two multi-mode adhesives Clearfil S(3) Bond Plus (Kuraray Noritake) and Scotchbond Universal (3M ESPE), both used following a 2-step E&R and 1-step SE mode, were applied to clinically relevant, flattened enamel surfaces. A composite (Filtek Z100; 3M ESPE) build-up was made in layers. After 1-week water storage at 37°C, all specimens were sectioned perpendicular to the interface to obtain rectangular sticks. A mini-iFT notch was prepared at the adhesive-enamel interface using a thin diamond blade under water cooling. Finally, the specimens were loaded in a 4-point bending test until failure. the mini-iFT onto human enamel was significantly higher for the adhesives applied in E&R mode versus those applied in SE mode. The lowest mini-iFT was found for the adhesives applied following a 1-step SE approach. SEM fracture analysis revealed that all fractures originated at the adhesive-enamel interface and that the induced crack propagated preferentially along this interface. mini-iFT appeared a valid alternative method to assess the mechanical properties of adhesive-enamel interfaces. Copyright © 2016 Elsevier Ltd. All rights reserved.