Rocket nozzle thermal shock tests in an arc heater facility

NASA Technical Reports Server (NTRS)

Painter, James H.; Williamson, Ronald A.

1986-01-01

A rocket motor nozzle thermal structural test technique that utilizes arc heated nitrogen to simulate a motor burn was developed. The technique was used to test four heavily instrumented full-scale Star 48 rocket motor 2D carbon/carbon segments at conditions simulating the predicted thermal-structural environment. All four nozzles survived the tests without catastrophic or other structural failures. The test technique demonstrated promise as a low cost, controllable alternative to rocket motor firing. The technique includes the capability of rapid termination in the event of failure, allowing post-test analysis.

A review of recent developments in flight test techniques at the Ames Research Center, Dryden Flight Research Facility

NASA Technical Reports Server (NTRS)

Layton, G. P.

1984-01-01

New flight test techniques in use at Ames Dryden are reviewed. The use of the pilot in combination with ground and airborne computational capabilities to maximize data return is discussed, including the remotely piloted research vehicle technique for high-risk testing, the remotely augmented vehicle technique for handling qualities research, and use of ground computed flight director information to fly unique profiles such as constant Reynolds number profiles through the transonic flight regime. Techniques used for checkout and design verification of systems-oriented aircraft are discussed, including descriptions of the various simulations, iron bird setups, and vehicle tests. Some newly developed techniques to support the aeronautical research disciplines are discussed, including a new approach to position-error determination, and the use of a large skin friction balance for the measurement of drag caused by various excrescencies.

Behavior driven testing in ALMA telescope calibration software

NASA Astrophysics Data System (ADS)

Gil, Juan P.; Garces, Mario; Broguiere, Dominique; Shen, Tzu-Chiang

2016-07-01

ALMA software development cycle includes well defined testing stages that involves developers, testers and scientists. We adapted Behavior Driven Development (BDD) to testing activities applied to Telescope Calibration (TELCAL) software. BDD is an agile technique that encourages communication between roles by defining test cases using natural language to specify features and scenarios, what allows participants to share a common language and provides a high level set of automated tests. This work describes how we implemented and maintain BDD testing for TELCAL, the infrastructure needed to support it and proposals to expand this technique to other subsystems.

NASA Langley Distributed Propulsion VTOL Tilt-Wing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development

NASA Technical Reports Server (NTRS)

Rothhaar, Paul M.; Murphy, Patrick C.; Bacon, Barton J.; Gregory, Irene M.; Grauer, Jared A.; Busan, Ronald C.; Croom, Mark A.

2014-01-01

Control of complex Vertical Take-Off and Landing (VTOL) aircraft traversing from hovering to wing born flight mode and back poses notoriously difficult modeling, simulation, control, and flight-testing challenges. This paper provides an overview of the techniques and advances required to develop the GL-10 tilt-wing, tilt-tail, long endurance, VTOL aircraft control system. The GL-10 prototype's unusual and complex configuration requires application of state-of-the-art techniques and some significant advances in wind tunnel infrastructure automation, efficient Design Of Experiments (DOE) tunnel test techniques, modeling, multi-body equations of motion, multi-body actuator models, simulation, control algorithm design, and flight test avionics, testing, and analysis. The following compendium surveys key disciplines required to develop an effective control system for this challenging vehicle in this on-going effort.

The development of in situ fracture toughness evaluation techniques in hydrogen environment

DOE PAGES

Wang, John Jy-An; Ren, Fei; Tan, Tin; ...

2014-12-19

Reliability of hydrogen pipelines and storage tanks is significantly influenced by the mechanical performance of the structural materials exposed in the hydrogen environment. Fracture behavior and fracture toughness are of specific interest since they are relevant to many catastrophic failures. However, many conventional fracture testing techniques are difficult to be realized under the presence of hydrogen. Thus it is desired to develop novel in situ techniques to study the fracture behavior of structural materials in hydrogen environments. In this study, special testing apparatus were designed to facilitate in situ fracture testing in H 2. A torsional fixture was developed tomore » utilize an emerging fracture testing technique, Spiral Notch Torsion Test (SNTT). The design concepts will be discussed. Preliminary in situ testing results indicated that the exposure to H 2 significantly reduces the fracture toughness of 4340 high strength steels by up to 50 percent. Furthermore, SNTT tests conducted in air demonstrated a significant fracture toughness reduction in samples subject to simulated welding heat treatment using Gleeble, which illustrated the effect of welding on the fracture toughness of this material.« less

An Airborne Parachute Compartment Test Bed for the Orion Parachute Test Program

NASA Technical Reports Server (NTRS)

Moore, James W.; Romero, Leah M.

2013-01-01

The test program developing parachutes for the Orion/MPCV includes drop tests with parachutes deployed from an Orion-like parachute compartment at a wide range of dynamic pressures. Aircraft and altitude constraints precluded the use of an Orion boilerplate capsule for several test points. Therefore, a dart-shaped test vehicle with a hi-fidelity mock-up of the Orion parachute compartment has been developed. The available aircraft options imposed constraints on the test vehicle development and concept of operations. Delivery of this test vehicle to the desired velocity, altitude, and orientation required for the test is a di cult problem involving multiple engineering disciplines. This paper describes the development of the test technique. The engineering challenges include extraction from an aircraft, reposition of the extraction parachute, and mid-air separation of two vehicles, neither of which has an active attitude control system. The desired separation behavior is achieved by precisely controlling the release point using on-board monitoring of the motion. The design of the test vehicle is also described. The trajectory simulations and other analyses used to develop this technique and predict the behavior of the test vehicle are reviewed in detail. The application of the technique on several successful drop tests is summarized.

Measurement of transmission loss characteristics using acoustic intensity techniques at the KU-FRL Acoustic Test Facility

NASA Technical Reports Server (NTRS)

Roskam, J.

1983-01-01

The transmission loss characteristics of panels using the acoustic intensity technique is presented. The theoretical formulation, installation of hardware, modifications to the test facility, and development of computer programs and test procedures are described. A listing of all the programs is also provided. The initial test results indicate that the acoustic intensity technique is easily adapted to measure transmission loss characteristics of panels. Use of this method will give average transmission loss values. The fixtures developed to position the microphones along the grid points are very useful in plotting the intensity maps of vibrating panels.

Analysis of distortion data from TF30-P-3 mixed compression inlet test

NASA Technical Reports Server (NTRS)

King, R. W.; Schuerman, J. A.; Muller, R. G.

1976-01-01

A program was conducted to reduce and analyze inlet and engine data obtained during testing of a TF30-P-3 engine operating behind a mixed compression inlet. Previously developed distortion analysis techniques were applied to the data to assist in the development of a new distortion methodology. Instantaneous distortion techniques were refined as part of the distortion methodology development. A technique for estimating maximum levels of instantaneous distortion from steady state and average turbulence data was also developed as part of the program.

Real-Time Onboard Global Nonlinear Aerodynamic Modeling from Flight Data

NASA Technical Reports Server (NTRS)

Brandon, Jay M.; Morelli, Eugene A.

2014-01-01

Flight test and modeling techniques were developed to accurately identify global nonlinear aerodynamic models onboard an aircraft. The techniques were developed and demonstrated during piloted flight testing of an Aermacchi MB-326M Impala jet aircraft. Advanced piloting techniques and nonlinear modeling techniques based on fuzzy logic and multivariate orthogonal function methods were implemented with efficient onboard calculations and flight operations to achieve real-time maneuver monitoring and analysis, and near-real-time global nonlinear aerodynamic modeling and prediction validation testing in flight. Results demonstrated that global nonlinear aerodynamic models for a large portion of the flight envelope were identified rapidly and accurately using piloted flight test maneuvers during a single flight, with the final identified and validated models available before the aircraft landed.

Development of a superconductor magnetic suspension and balance prototype facility for studying the feasibility of applying this technique to large scale aerodynamic testing

NASA Technical Reports Server (NTRS)

Zapata, R. N.; Humphris, R. R.; Henderson, K. C.

1975-01-01

The basic research and development work towards proving the feasibility of operating an all-superconductor magnetic suspension and balance device for aerodynamic testing is presented. The feasibility of applying a quasi-six-degree-of freedom free support technique to dynamic stability research was studied along with the design concepts and parameters for applying magnetic suspension techniques to large-scale aerodynamic facilities. A prototype aerodynamic test facility was implemented. Relevant aspects of the development of the prototype facility are described in three sections: (1) design characteristics; (2) operational characteristics; and (3) scaling to larger facilities.

Cost effectiveness as applied to the Viking Lander systems-level thermal development test program

NASA Technical Reports Server (NTRS)

Buna, T.; Shupert, T. C.

1974-01-01

The economic aspects of thermal testing at the systems-level as applied to the Viking Lander Capsule thermal development program are reviewed. The unique mission profile and pioneering scientific goals of Viking imposed novel requirements on testing, including the development of a simulation technique for the Martian thermal environment. The selected approach included modifications of an existing conventional thermal vacuum facility, and improved test-operational techniques that are applicable to the simulation of the other mission phases as well, thereby contributing significantly to the cost effectiveness of the overall thermal test program.

Noncontact techniques for diesel engine diagnostics using exhaust waveform analysis

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

Gore, D.A.; Cooke, G.J.

1987-01-01

RCA Corporation's continuing efforts to develop noncontact test techniques for diesel engines have led to recent advancements in deep engine diagnostics. The U.S. Army Tank-Automotive Command (TACOM) has been working with RCA for the development of new noncontact sensors and test techniques which use these sensors in conjunction with their family of Simplified Test Equipment (STE) to perform vehicle diagnostics. The STE systems are microprocessor-based maintenance tools that assist the Army mechanic in diagnosing malfunctions in both tactical and combat vehicles. The test systems support the mechanic by providing the sophisticated signal processing capabilities necessary for a wide range ofmore » diagnostic testing including exhaust waveform analysis.« less

Adaptive wall research with two- and three-dimensional models in low speed and transonic tunnels

NASA Technical Reports Server (NTRS)

Lewis, M. C.; Neal, G.; Goodyer, M. J.

1988-01-01

This paper summarises recent research at the University of Southampton into adaptive wall technology and outlines the direction of current efforts. The work is aimed at developing techniques for use in test sections where the top and bottom walls may be adjusted in single curvature. Wall streamlining eliminates, as far as experimentally possible, the top and bottom wall interference in low speed and transonic aerofoil testing. A streamlining technique has been developed for low speeds which allows the testing of swept wing panels in low interference environments. At higher speeds, a comparison of several two-dimensional transonic streamlining algorithms has been made and a technique for streamlining with a choked test section has also been developed. Three-dimensional work has mainly concentrated on tests of sidewall mounted half-wings and the development of the software packages required to assess interference and to adjust the flexible walls. It has been demonstrated that two-dimensional wall adaptation can significantly modify the level of wall interference around relatively large three-dimensional models. The residual interferences are small and are probably amenable to standard post-test correction methods. Tests on a calibrated wing-body model are planned in the near future to further validate the proposed streamlining technique.

Robert's Rules for Optimal Learning: Model Development, Field Testing, Implications!

ERIC Educational Resources Information Center

McGinty, Robert L.

The value of accelerated learning techniques developed by the national organization for Suggestive Accelerated Learning Techniques (SALT) was tested in a study using Administrative Policy students taking the capstone course in the Eastern Washington University School of Business. Educators have linked the brain and how it functions to various…

Comparison of Commercial Electromagnetic Interface Test Techniques to NASA Electromagnetic Interference Test Techniques

NASA Astrophysics Data System (ADS)

Smith, V.

2000-11-01

This report documents the development of analytical techniques required for interpreting and comparing space systems electromagnetic interference test data with commercial electromagnetic interference test data using NASA Specification SSP 30237A "Space Systems Electromagnetic Emission and Susceptibility Requirements for Electromagnetic Compatibility." The PSpice computer simulation results and the laboratory measurements for the test setups under study compare well. The study results, however, indicate that the transfer function required to translate test results of one setup to another is highly dependent on cables and their actual layout in the test setup. Since cables are equipment specific and are not specified in the test standards, developing a transfer function that would cover all cable types (random, twisted, or coaxial), sizes (gauge number and length), and layouts (distance from the ground plane) is not practical.

Comparison of Commercial Electromagnetic Interface Test Techniques to NASA Electromagnetic Interference Test Techniques

NASA Technical Reports Server (NTRS)

Smith, V.; Minor, J. L. (Technical Monitor)

2000-01-01

This report documents the development of analytical techniques required for interpreting and comparing space systems electromagnetic interference test data with commercial electromagnetic interference test data using NASA Specification SSP 30237A "Space Systems Electromagnetic Emission and Susceptibility Requirements for Electromagnetic Compatibility." The PSpice computer simulation results and the laboratory measurements for the test setups under study compare well. The study results, however, indicate that the transfer function required to translate test results of one setup to another is highly dependent on cables and their actual layout in the test setup. Since cables are equipment specific and are not specified in the test standards, developing a transfer function that would cover all cable types (random, twisted, or coaxial), sizes (gauge number and length), and layouts (distance from the ground plane) is not practical.

Development of a Pulsed Pressure-Based Technique for Cavitation Damage Study

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

Ren, Fei; Wang, Jy-An John; Liu, Yun

2012-01-01

Cavitation occurs in many fluid systems and can lead to severe material damage. To assist the study of cavitation damage, a novel testing method utilizing pulsed pressure was developed. In this talk, the scientific background and the technical approach of this development are present and preliminary testing results are discussed. It is expected that this technique can be used to evaluate cavitation damage under various testing conditions including harsh environments such as those relevant to geothermal power generation.

Global Aerodynamic Modeling for Stall/Upset Recovery Training Using Efficient Piloted Flight Test Techniques

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.; Cunningham, Kevin; Hill, Melissa A.

2013-01-01

Flight test and modeling techniques were developed for efficiently identifying global aerodynamic models that can be used to accurately simulate stall, upset, and recovery on large transport airplanes. The techniques were developed and validated in a high-fidelity fixed-base flight simulator using a wind-tunnel aerodynamic database, realistic sensor characteristics, and a realistic flight deck representative of a large transport aircraft. Results demonstrated that aerodynamic models for stall, upset, and recovery can be identified rapidly and accurately using relatively simple piloted flight test maneuvers. Stall maneuver predictions and comparisons of identified aerodynamic models with data from the underlying simulation aerodynamic database were used to validate the techniques.

Development and evaluation of an automatic labeling technique for spring small grains

NASA Technical Reports Server (NTRS)

Crist, E. P.; Malila, W. A. (Principal Investigator)

1981-01-01

A labeling technique is described which seeks to associate a sampling entity with a particular crop or crop group based on similarity of growing season and temporal-spectral patterns of development. Human analyst provide contextual information, after which labeling decisions are made automatically. Results of a test of the technique on a large, multi-year data set are reported. Grain labeling accuracies are similar to those achieved by human analysis techniques, while non-grain accuracies are lower. Recommendations for improvments and implications of the test results are discussed.

The Trajectory of Techniques: Lessons from the Past.

ERIC Educational Resources Information Center

Crease, Robert P.

1992-01-01

Discusses role of laboratory techniques in scientific investigations. Describes Rutherford's development of scattering techniques and von Wassermann's development of test for syphilis. States that discovering an effect requires a brilliant scientist, however, making it a technique requires that it be made usable by ordinary people. Uses Moseley's…

The Inception of OMA in the Development of Modal Testing Technology for Wind Turbines

NASA Technical Reports Server (NTRS)

James, George H., III; Carne. Thomas G.

2008-01-01

Wind turbines are immense, flexible structures with aerodynamic forces acting on the rotating blades at harmonics of the turbine rotational frequency, which are comparable to the modal frequencies of the structure. Predicting and experimentally measuring the modal frequencies of wind turbines has been important to their successful design and operation. Performing modal tests on wind turbine structures over 100 meters tall is a substantial challenge, which has inspired innovative developments in modal test technology. For wind turbines, a further complication is that the modal frequencies are dependent on the turbine rotation speed. The history and development of a new technique for acquiring the modal parameters using output-only response data, called the Natural Excitation Technique (NExT), will be reviewed, showing historical tests and techniques. The initial attempts at output-only modal testing began in the late 1980's with the development of NExT in the 1990's. NExT was a predecessor to OMA, developed to overcome these challenges of testing immense structures excited with environmental inputs. We will trace the difficulties and successes of wind turbine modal testing from 1982 to the present. Keywords: OMA, Modal Analysis, NExT, Wind Turbines, Wind Excitation

Radio-controlled model design and testing techniques for stall/spin evaluation of general-aviation aircraft

NASA Technical Reports Server (NTRS)

Burk, S. M., Jr.; Wilson, C. F., Jr.

1975-01-01

A relatively inexpensive radio-controlled model stall/spin test technique was developed. Operational experiences using the technique are presented. A discussion of model construction techniques, spin-recovery parachute system, data recording system, and movie camera tracking system is included. Also discussed are a method of measuring moments of inertia, scaling of engine thrust, cost and time required to conduct a program, and examples of the results obtained from the flight tests.

Development of the technology for the fabrication of reliable laminar from control panels

NASA Technical Reports Server (NTRS)

Meade, L. E.; Kays, A. O.; Ferrill, R. S.; Young, H. R.

1977-01-01

Materials were assessed and fabrication techniques were developed for use in the manufacture of wing surface materials compatible with the application of both aluminum alloys and nonmetallic composites. The concepts investigated included perforations and slots in the metallic test panels and microporosity and perforations in the composite test panels. Perforations were produced in the metallic test panels by the electron beam process and slots were developed by controlled gaps between the metal sheets. Microporosity was produced in the composite test panels by the resin bleed process, and perforations were produced by the fugitive fiber technique. Each of these concepts was fabricated into test panels, and air flow tests were conducted on the panels.

Rasch Analysis for Instrument Development: Why, When, and How?

ERIC Educational Resources Information Center

Boone, William J.

2016-01-01

This essay describes Rasch analysis psychometric techniques and how such techniques can be used by life sciences education researchers to guide the development and use of surveys and tests. Specifically, Rasch techniques can be used to document and evaluate the measurement functioning of such instruments. Rasch techniques also allow researchers to…

Flight control system design factors for applying automated testing techniques

NASA Technical Reports Server (NTRS)

Sitz, Joel R.; Vernon, Todd H.

1990-01-01

The principal design features and operational experiences of the X-29 forward-swept-wing aircraft and F-18 high alpha research vehicle (HARV) automated test systems are discussed. It is noted that operational experiences in developing and using these automated testing techniques have highlighted the need for incorporating target system features to improve testability. Improved target system testability can be accomplished with the addition of nonreal-time and real-time features. Online access to target system implementation details, unobtrusive real-time access to internal user-selectable variables, and proper software instrumentation are all desirable features of the target system. Also, test system and target system design issues must be addressed during the early stages of the target system development. Processing speeds of up to 20 million instructions/s and the development of high-bandwidth reflective memory systems have improved the ability to integrate the target system and test system for the application of automated testing techniques. It is concluded that new methods of designing testability into the target systems are required.

A new technique for measuring listening and reading literacy in developing countries

NASA Astrophysics Data System (ADS)

Greene, Barbara A.; Royer, James M.; Anzalone, Stephen

1990-03-01

One problem in evaluating educational interventions in developing countries is the absence of tests that adequately reflect the culture and curriculum. The Sentence Verification Technique is a new procedure for measuring reading and listening comprehension that allows for the development of tests based on materials indigenous to a given culture. The validity of using the Sentence Verification Technique to measure reading comprehension in Grenada was evaluated in the present study. The study involved 786 students at standards 3, 4 and 5. The tests for each standard consisted of passages that varied in difficulty. The students identified as high ability students in all three standards performed better than those identified as low ability. All students performed better with easier passages. Additionally, students in higher standards performed bettter than students in lower standards on a given passage. These results supported the claim that the Sentence Verification Technique is a valid measure of reading comprehension in Grenada.

Control technique for planetary rover

NASA Technical Reports Server (NTRS)

Nakatani, Ichiro; Kubota, Takashi; Adachi, Tadashi; Saitou, Hiroaki; Okamoto, Sinya

1994-01-01

Beginning next century, several schemes for sending a planetary rover to the moon or Mars are being planned. As part of the development program, autonomous navigation technology is being studied to allow the rover the ability to move autonomously over a long range of unknown planetary surface. In the previous study, we ran the autonomous navigation experiment on an outdoor test terrain by using a rover test-bed that was controlled by a conventional sense-plan-act method. In some cases during the experiment, a problem occurred with the rover moving into untraversable areas. To improve this situation, a new control technique has been developed that gives the rover the ability of reacting to the outputs of the proximity sensors, a reaction behavior if you will. We have developed a new rover test-bed system on which an autonomous navigation experiment was performed using the newly developed control technique. In this outdoor experiment, the new control technique effectively produced the control command for the rover to avoid obstacles and be guided to the goal point safely.

Limit Cycle Analysis Applied to the Oscillations of Decelerating Blunt-Body Entry Vehicles

NASA Technical Reports Server (NTRS)

Schoenenberger, Mark; Queen, Eric M.

2008-01-01

Many blunt-body entry vehicles have nonlinear dynamic stability characteristics that produce self-limiting oscillations in flight. Several different test techniques can be used to extract dynamic aerodynamic coefficients to predict this oscillatory behavior for planetary entry mission design and analysis. Most of these test techniques impose boundary conditions that alter the oscillatory behavior from that seen in flight. Three sets of test conditions, representing three commonly used test techniques, are presented to highlight these effects. Analytical solutions to the constant-coefficient planar equations-of-motion for each case are developed to show how the same blunt body behaves differently depending on the imposed test conditions. The energy equation is applied to further illustrate the governing dynamics. Then, the mean value theorem is applied to the energy rate equation to find the effective damping for an example blunt body with nonlinear, self-limiting dynamic characteristics. This approach is used to predict constant-energy oscillatory behavior and the equilibrium oscillation amplitudes for the various test conditions. These predictions are verified with planar simulations. The analysis presented provides an overview of dynamic stability test techniques and illustrates the effects of dynamic stability, static aerodynamics and test conditions on observed dynamic motions. It is proposed that these effects may be leveraged to develop new test techniques and refine test matrices in future tests to better define the nonlinear functional forms of blunt body dynamic stability curves.

Development of an invitro technique to use mouse embryonic stem cell in evaluating effects of xenobiotics

EPA Science Inventory

Our goal has been to develop a high-throughput, in vitro technique for evaluating the effects of xenobiotics using mouse embryonic stem cells (mESCs). We began with the Embryonic Stem Cell Test (EST), which is used to predict the embryotoxic potential of a test compound by combin...

Experimental investigations into cryosorption pumping of plasma exhaust

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

Perinic, D.; Mack, A.

1988-09-01

Within the framework of the European Fusion Technology Programme the Karlsruhe Nuclear Research Centre has been awarded a contract for the development of cryosorption panels for compound cryopumps of the NEt plasma exhaust pumping system. This task includes the development of a bonding technique for porous sorbent materials with metal substrates and a test programme for development and optimization of cryopanels. A variety of material combinations for sorbent, bonding and substrate were evaluated and listed in a test matrix. Bonding tests involving soldering, cementing and plasma spraying techniques have been carried out.

[The quantitative testing of V617F mutation in gen JAK2 using pyrosequencing technique].

PubMed

Dunaeva, E A; Mironov, K O; Dribnokhodova, T E; Subbotina, E E; Bashmakova; Ol'hovskiĭ, I A; Shipulin, G A

2014-11-01

The somatic mutation V617F in gen JAK2 is a frequent cause of chronic myeloprolific diseases not conditioned by BCR/ABL mutation. The quantitative testing of relative percentage of mutant allele can be used in establishing severity of disease and its prognosis and in prescription of remedy inhibiting activity of JAK2. To quantitatively test mutation the pyrosequencing technique was applied. The developed technique permits detecting and quantitatively, testing percentage of mutation fraction since 7%. The "gray zone" is presented by samples with percentage of mutant allele from 4% to 7%. The dependence of expected percentage of mutant fraction in analyzed sample from observed value of signal is described by equation of line with regression coefficients y = - 0.97, x = -1.32 and at that measurement uncertainty consists ± 0.7. The developed technique is approved officially on clinical material from 192 patients with main forms of myeloprolific diseases not conditioned by BCR/ABL mutation. It was detected 64 samples with mautant fraction percentage from 13% to 91%. The developed technique permits implementing monitoring of therapy of myeloprolific diseases and facilitates to optimize tactics of treatment.

Vocabulary Development: Teaching vs. Testing.

ERIC Educational Resources Information Center

Nilsen, Alleen Pace; Nilsen, Don L. F.

2003-01-01

Considers how with no training in how to teach vocabulary skills, many teachers transfer to their classroom the same techniques that they see test makers using. Offers a chart to encourage thinking about the ways that standardized testing techniques differ from good teaching and learning practices. Argues that educators should provide students…

The Field-tested Learning Assessment Guide (FLAG): A Community Repository of Proven Alternative Assessment Instruments for STEM Education

NASA Astrophysics Data System (ADS)

Zeilik, M.; Garvin-Doxas, K.

2003-12-01

FLAG, the Field-tested Learning Assessment Guide (http://www.flaguide.org/) is a NSF funded website that offers broadly-applicable, self-contained modular classroom assessment techniques (CATs) and discipline-specific tools for STEM instructors creating new approaches to evaluate student learning, attitudes and performance. In particular, the FLAG contains proven techniques for alterative assessments---those needed for reformed, innovative STEM courses. Each tool has been developed, tested and refined in real classrooms at colleges and universities. The FLAG also contains an assessment primer, a section to help you select the most appropriate assessment technique(s) for your course goals, and other resources. In addition to references on instrument development and field-tested instruments on attitudes towards science, the FLAG also includes discipline-specific tools in Physics, Astronomy, Biology, and Mathematics. Building of the Geoscience collection is currently under way with the development of an instrument for detecting misconceptions of incoming freshmen on Space Science, which is being developed with the help of the Committee on Space Science and Astronomy of the American Association of Physics Teachers. Additional field-tested resources from the Geosciences are solicited from the community. Contributions should be sent to Michael Zeilik, zeilik@la.unm.edu. This work has been supported in part by NSF grant DUE 99-81155.

Real-Time Global Nonlinear Aerodynamic Modeling for Learn-To-Fly

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

2016-01-01

Flight testing and modeling techniques were developed to accurately identify global nonlinear aerodynamic models for aircraft in real time. The techniques were developed and demonstrated during flight testing of a remotely-piloted subscale propeller-driven fixed-wing aircraft using flight test maneuvers designed to simulate a Learn-To-Fly scenario. Prediction testing was used to evaluate the quality of the global models identified in real time. The real-time global nonlinear aerodynamic modeling algorithm will be integrated and further tested with learning adaptive control and guidance for NASA Learn-To-Fly concept flight demonstrations.

A high temperature testing system for ceramic composites

NASA Technical Reports Server (NTRS)

Hemann, John

1994-01-01

Ceramic composites are presently being developed for high temperature use in heat engine and space power system applications. The operating temperature range is expected to be 1090 to 1650 C (2000 F to 3000 F). Very little material data is available at these temperatures and, therefore, it is desirable to thoroughly characterize the basic unidirectional fiber reinforced ceramic composite. This includes testing mainly for mechanical material properties at high temperatures. The proper conduct of such characterization tests requires the development of a tensile testing system includes unique gripping, heating, and strain measuring devices which require special considerations. The system also requires an optimized specimen shape. The purpose of this paper is to review various techniques for measuring displacements or strains, preferably at elevated temperatures. Due to current equipment limitations it is assumed that the specimen is to be tested at a temperature of 1430 C (2600F) in an oxidizing atmosphere. For the most part, previous high temperature material characterization tests, such as flexure and tensile tests, have been performed in inert atmospheres. Due to the harsh environment in which the ceramic specimen is to be tested, many conventional strain measuring techniques can not be applied. Initially a brief description of the more commonly used mechanical strain measuring techniques is given. Major advantages and disadvantages with their application to high temperature tensile testing of ceramic composites are discussed. Next, a general overview is given for various optical techniques. Advantages and disadvantages which are common to these techniques are noted. The optical methods for measuring strain or displacement are categorized into two sections. These include real-time techniques. Finally, an optical technique which offers optimum performance with the high temperature tensile testing of ceramic composites is recommended.

Development and Evaluation of a Performance Modeling Flight Test Approach Based on Quasi Steady-State Maneuvers

NASA Technical Reports Server (NTRS)

Yechout, T. R.; Braman, K. B.

1984-01-01

The development, implementation and flight test evaluation of a performance modeling technique which required a limited amount of quasisteady state flight test data to predict the overall one g performance characteristics of an aircraft. The concept definition phase of the program include development of: (1) the relationship for defining aerodynamic characteristics from quasi steady state maneuvers; (2) a simplified in flight thrust and airflow prediction technique; (3) a flight test maneuvering sequence which efficiently provided definition of baseline aerodynamic and engine characteristics including power effects on lift and drag; and (4) the algorithms necessary for cruise and flight trajectory predictions. Implementation of the concept include design of the overall flight test data flow, definition of instrumentation system and ground test requirements, development and verification of all applicable software and consolidation of the overall requirements in a flight test plan.

Fostering students’ thinking skill and social attitude through STAD cooperative learning technique on tenth grade students of chemistry class

NASA Astrophysics Data System (ADS)

Kriswintari, D.; Yuanita, L.; Widodo, W.

2018-04-01

The aim of this study was to develop chemistry learning package using Student Teams Achievement Division (STAD) cooperative learning technique to foster students’ thinking skills and social attitudes. The chemistry learning package consisting of lesson plan, handout, students’ worksheet, thinking skill test, and observation sheet of social attitude was developed using the Dick and Carey model. Research subject of this study was chemistry learning package using STAD which was tried out on tenth grade students of SMA Trimurti Surabaya. The tryout was conducted using the one-group pre-test post-test design. Data was collected through observation, test, and questionnaire. The obtained data were analyzed using descriptive qualitative analysis. The findings of this study revealed that the developed chemistry learning package using STAD cooperative learning technique was categorized valid, practice and effective to be implemented in the classroom to foster students’ thinking skill and social attitude.

Development of flexural vibration inspection techniques to rapidly assess the structural health of rural bridge systems

Treesearch

Brian K. Brashaw; Robert Vatalaro; Xiping Wang; Kevin Sarvela; James P. Wacker

2008-01-01

Approximately 4,000 vehicle bridges in the State of Minnesota contain structural timber members. Recent research at the University of Minnesota Duluth Natural Resources Research Institute (UMD NRRI) has been conducted on vibration testing of timber bridges as a means of developing rapid in-place testing techniques for assessing the structural health of bridges. The...

International Instrumentation Symposium, 34th, Albuquerque, NM, May 2-6, 1988, Proceedings

NASA Astrophysics Data System (ADS)

Various papers on aerospace instrumentation are presented. The general topics addressed include: blast and shock, wind tunnel instrumentations and controls, digital/optical sensors, software design/development, special test facilities, fiber optic techniques, electro/fiber optical measurement systems, measurement uncertainty, real time systems, pressure. Also discussed are: flight test and avionics instrumentation, data acquisition techniques, computer applications, thermal force and displacement, science and government, modeling techniques, reentry vehicle testing, strain and pressure.

Rapid Model Fabrication and Testing for Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Buck, Gregory M.

2000-01-01

Advanced methods for rapid fabrication and instrumentation of hypersonic wind tunnel models are being developed and evaluated at NASA Langley Research Center. Rapid aeroheating model fabrication and measurement techniques using investment casting of ceramic test models and thermographic phosphors are reviewed. More accurate model casting techniques for fabrication of benchmark metal and ceramic test models are being developed using a combination of rapid prototype patterns and investment casting. White light optical scanning is used for coordinate measurements to evaluate the fabrication process and verify model accuracy to +/- 0.002 inches. Higher-temperature (<210C) luminescent coatings are also being developed for simultaneous pressure and temperature mapping, providing global pressure as well as global aeroheating measurements. Together these techniques will provide a more rapid and complete experimental aerodynamic and aerothermodynamic database for future aerospace vehicles.

A direct-measurement technique for estimating discharge-chamber lifetime. [for ion thrusters

NASA Technical Reports Server (NTRS)

Beattie, J. R.; Garvin, H. L.

1982-01-01

The use of short-term measurement techniques for predicting the wearout of ion thrusters resulting from sputter-erosion damage is investigated. The laminar-thin-film technique is found to provide high precision erosion-rate data, although the erosion rates are generally substantially higher than those found during long-term erosion tests, so that the results must be interpreted in a relative sense. A technique for obtaining absolute measurements is developed using a masked-substrate arrangement. This new technique provides a means for estimating the lifetimes of critical discharge-chamber components based on direct measurements of sputter-erosion depths obtained during short-duration (approximately 1 hr) tests. Results obtained using the direct-measurement technique are shown to agree with sputter-erosion depths calculated for the plasma conditions of the test. The direct-measurement approach is found to be applicable to both mercury and argon discharge-plasma environments and will be useful for estimating the lifetimes of inert gas and extended performance mercury ion thrusters currently under development.

Development of Guidelines for In-Situ Repair of SLS-Class Composite Flight Hardware

NASA Technical Reports Server (NTRS)

Weber, Thomas P., Jr.; Cox, Sarah B.

2018-01-01

The purpose of composite repair development at KSC (John F. Kennedy Space Center) is to provide support to the CTE (Composite Technology for Exploration) project. This is a multi-space center effort with the goal of developing bonded joint technology for SLS (Space Launch System) -scale composite hardware. At KSC, effective and efficient repair processes need to be developed to allow for any potential damage to composite components during transport or launch preparation. The focus of the composite repair development internship during the spring of 2018 was on the documentation of repair processes and requirements for process controls based on techniques developed through hands-on work with composite test panels. Three composite test panels were fabricated for the purpose of repair and surface preparation testing. The first panel included a bonded doubler and was fabricated to be damaged and repaired. The second and third panels were both fabricated to be cut into lap-shear samples to test the strength of bond of different surface preparation techniques. Additionally, jointed composite test panels were impacted at MSFC (Marshall Space Flight Center) and analyzed for damage patterns. The observations after the impact tests guided the repair procedure at KSC to focus on three repair methods. With a finalized repair plan in place, future work will include the strength testing of different surface preparation techniques, demonstration of repair methods, and repair of jointed composite test panels being impacted at MSFC.

Applying modern psychometric techniques to melodic discrimination testing: Item response theory, computerised adaptive testing, and automatic item generation.

PubMed

Harrison, Peter M C; Collins, Tom; Müllensiefen, Daniel

2017-06-15

Modern psychometric theory provides many useful tools for ability testing, such as item response theory, computerised adaptive testing, and automatic item generation. However, these techniques have yet to be integrated into mainstream psychological practice. This is unfortunate, because modern psychometric techniques can bring many benefits, including sophisticated reliability measures, improved construct validity, avoidance of exposure effects, and improved efficiency. In the present research we therefore use these techniques to develop a new test of a well-studied psychological capacity: melodic discrimination, the ability to detect differences between melodies. We calibrate and validate this test in a series of studies. Studies 1 and 2 respectively calibrate and validate an initial test version, while Studies 3 and 4 calibrate and validate an updated test version incorporating additional easy items. The results support the new test's viability, with evidence for strong reliability and construct validity. We discuss how these modern psychometric techniques may also be profitably applied to other areas of music psychology and psychological science in general.

Techniques for Embedding Instrumentation in Pressure Vessel Test Articles

NASA Technical Reports Server (NTRS)

Cornelius, Michael

2006-01-01

Many interesting structural and thermal events occur in materials that are housed within a surrounding pressure vessel. In order to measure the environment during these events and explore their causes instrumentation must be installed on or in the material. Transducers can be selected that are small enough to be embedded within the test material but these instruments must interface with an external system in order to apply excitation voltages and output the desired data. The methods for installing the instrumentation and creating an interface are complicated when the material is located in a case or housing containing high pressures and hot gases. Installation techniques for overcoming some of these difficulties were developed while testing a series of small-scale solid propellant and hybrid rocket motors at Marshall Space Flight Center. These techniques have potential applications in other test articles where data are acquired from materials that require containment due to the severe environment encountered during the test process. This severe environment could include high pressure, hot gases, or ionized atmospheres. The development of these techniques, problems encountered, and the lessons learned from the ongoing testing process are summarized.

The Comparison Of In-Flight Pitot Static Calibration Method By Using Radio Altimeter As Reference with GPS and Tower Fly By Methods On CN235-100 MPA

NASA Astrophysics Data System (ADS)

Derajat; Hariowibowo, Hindawan

2018-04-01

The new proposed In-Flight Pitot Static Calibration Method has been carried out during Development and Qualification of CN235-100 MPA (Military Patrol Aircraft). This method is expected to reduce flight hours, less human resources required, no additional special equipment, simple analysis calculation and finally by using this method it is expected to automatically minimized operational cost. At The Indonesian Aerospace (IAe) Flight Test Center Division, the development and updating of new flight test technique and data analysis method as specially for flight physics test subject are still continued to be developed as long as it safety for flight and give additional value for the industrial side. More than 30 years, Flight Test Data Engineers at The Flight Test center Division work together with the Air Crew (Test Pilots, Co-Pilots, and Flight Test Engineers) to execute the flight test activity with standard procedure for both the existance or development test techniques and test data analysis. In this paper the approximation of mathematical model, data reduction and flight test technique of The In-Flight Pitot Static Calibration by using Radio Altimeter as reference will be described and the test results had been compared with another methods ie. By using Global Position System (GPS) and the traditional method (Tower Fly By Method) which were used previously during this Flight Test Program (Ref. [10]). The flight test data case are using CN235-100 MPA flight test data during development and Qualification Flight Test Program at Cazaux Airport, France, in June-November 2009 (Ref. [2]).

Testing and characterizations of infrared sensor over the temperature range of 2 Kelvin to 300 Kelvin

NASA Technical Reports Server (NTRS)

Hansen, R. G.

1983-01-01

Various cryogenic techniques were used to evaluate state of the art electro-optic devices. As research, development, and production demands require more sensitive testing techniques, faster test results, and higher production throughput, the emphasis on supporting cryogenic systems increases. The three traditional methods currently utilized in electro-optic device testing are discussed: (1) liquid contaiment dewars; (2) liquid transfer systems; and (3) closed cycle refrigeration systems. Advantages, disadvantages, and the current state of the art of each of these cryogenic techniques is discussed.

Automatic Parameter Tuning for the Morpheus Vehicle Using Particle Swarm Optimization

NASA Technical Reports Server (NTRS)

Birge, B.

2013-01-01

A high fidelity simulation using a PC based Trick framework has been developed for Johnson Space Center's Morpheus test bed flight vehicle. There is an iterative development loop of refining and testing the hardware, refining the software, comparing the software simulation to hardware performance and adjusting either or both the hardware and the simulation to extract the best performance from the hardware as well as the most realistic representation of the hardware from the software. A Particle Swarm Optimization (PSO) based technique has been developed that increases speed and accuracy of the iterative development cycle. Parameters in software can be automatically tuned to make the simulation match real world subsystem data from test flights. Special considerations for scale, linearity, discontinuities, can be all but ignored with this technique, allowing fast turnaround both for simulation tune up to match hardware changes as well as during the test and validation phase to help identify hardware issues. Software models with insufficient control authority to match hardware test data can be immediately identified and using this technique requires very little to no specialized knowledge of optimization, freeing model developers to concentrate on spacecraft engineering. Integration of the PSO into the Morpheus development cycle will be discussed as well as a case study highlighting the tool's effectiveness.

Status of the Flooding Fragility Testing Development

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

Pope, C. L.; Savage, B.; Bhandari, B.

2016-06-01

This report provides an update on research addressing nuclear power plant component reliability under flooding conditions. The research includes use of the Component Flooding Evaluation Laboratory (CFEL) where individual components and component subassemblies will be tested to failure under various flooding conditions. The resulting component reliability data can then be incorporated with risk simulation strategies to provide a more thorough representation of overall plant risk. The CFEL development strategy consists of four interleaved phases. Phase 1 addresses design and application of CFEL with water rise and water spray capabilities allowing testing of passive and active components including fully electrified components.more » Phase 2 addresses research into wave generation techniques followed by the design and addition of the wave generation capability to CFEL. Phase 3 addresses methodology development activities including small scale component testing, development of full scale component testing protocol, and simulation techniques including Smoothed Particle Hydrodynamic (SPH) based computer codes. Phase 4 involves full scale component testing including work on full scale component testing in a surrogate CFEL testing apparatus.« less

Mosquito Control Techniques Developed for the US Military

USDA-ARS?s Scientific Manuscript database

The USDA developed and field tested new techniques to reduce the risk to deployed military troops from vector-borne diseases. Some of the methods developed included (1) novel military personal protection methods, (2) barrier treatments of artificial materials and natural vegetation, and (3) ground a...

High temperature UF6 RF plasma experiments applicable to uranium plasma core reactors

NASA Technical Reports Server (NTRS)

Roman, W. C.

1979-01-01

An investigation was conducted using a 1.2 MW RF induction heater facility to aid in developing the technology necessary for designing a self critical fissioning uranium plasma core reactor. Pure, high temperature uranium hexafluoride (UF6) was injected into an argon fluid mechanically confined, steady state, RF heated plasma while employing different exhaust systems and diagnostic techniques to simulate and investigate some potential characteristics of uranium plasma core nuclear reactors. The development of techniques and equipment for fluid mechanical confinement of RF heated uranium plasmas with a high density of uranium vapor within the plasma, while simultaneously minimizing deposition of uranium and uranium compounds on the test chamber peripheral wall, endwall surfaces, and primary exhaust ducts, is discussed. The material tests and handling techniques suitable for use with high temperature, high pressure, gaseous UF6 are described and the development of complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma, effluent exhaust gases, and residue deposited on the test chamber and exhaust system components is reported.

The DAST-1 remotely piloted research vehicle development and initial flight testing

NASA Technical Reports Server (NTRS)

Kotsabasis, A.

1981-01-01

The development and initial flight testing of the DAST (drones for aerodynamic and structural testing) remotely piloted research vehicle, fitted with the first aeroelastic research wing ARW-I are presented. The ARW-I is a swept supercritical wing, designed to exhibit flutter within the vehicle's flight envelope. An active flutter suppression system (FSS) designed to increase the ARW-I flutter boundary speed by 20 percent is described. The development of the FSS was based on prediction techniques of structural and unsteady aerodynamic characteristics. A description of the supporting ground facilities and aircraft systems involved in the remotely piloted research vehicle (RPRV) flight test technique is given. The design, specification, and testing of the remotely augmented vehicle system are presented. A summary of the preflight and flight test procedures associated with the RPRV operation is given. An evaluation of the blue streak test flight and the first and second ARW-I test flights is presented.

Quantitative Image Analysis Techniques with High-Speed Schlieren Photography

NASA Technical Reports Server (NTRS)

Pollard, Victoria J.; Herron, Andrew J.

2017-01-01

Optical flow visualization techniques such as schlieren and shadowgraph photography are essential to understanding fluid flow when interpreting acquired wind tunnel test data. Output of the standard implementations of these visualization techniques in test facilities are often limited only to qualitative interpretation of the resulting images. Although various quantitative optical techniques have been developed, these techniques often require special equipment or are focused on obtaining very precise and accurate data about the visualized flow. These systems are not practical in small, production wind tunnel test facilities. However, high-speed photography capability has become a common upgrade to many test facilities in order to better capture images of unsteady flow phenomena such as oscillating shocks and flow separation. This paper describes novel techniques utilized by the authors to analyze captured high-speed schlieren and shadowgraph imagery from wind tunnel testing for quantification of observed unsteady flow frequency content. Such techniques have applications in parametric geometry studies and in small facilities where more specialized equipment may not be available.

Transverse vibration techniques : logs to structural systems

Treesearch

Robert J. Ross

2008-01-01

Transverse vibration as a nondestructive testing and evaluation technique was first examined in the early 1960s. Initial research and development efforts focused on clear wood, lumber, and laminated products. Out of those efforts, tools were developed that are used today to assess lumber properties. Recently, use of this technique has been investigated for evaluating a...

Testing--1,2,...523,...641,...999--Testing: The MDT Multi-Digit Technique Applied to Science Education.

ERIC Educational Resources Information Center

Anderson, Paul S.; Schoner, James S.

The MDT multi-digit technique, a development in testing technology, is described; and its application to science classrooms is discussed. Some actual materials for use in a cell biology class are included. The primary characteristic of an MDT multi-digit test is a long list of possible responses, with each term marked with a three-digit number…

Applications of infrared thermography for nondestructive testing of fatigue cracks in steel bridges

NASA Astrophysics Data System (ADS)

Sakagami, Takahide; Izumi, Yui; Kobayashi, Yoshihiro; Mizokami, Yoshiaki; Kawabata, Sunao

2014-05-01

In recent years, fatigue crack propagations in aged steel bridge which may lead to catastrophic structural failures have become a serious problem. For large-scale steel structures such as orthotropic steel decks in highway bridges, nondestructive inspection of deteriorations and fatigue damages are indispensable for securing their safety and for estimating their remaining strength. As conventional NDT techniques for steel bridges, visual testing, magnetic particle testing and ultrasonic testing have been commonly employed. However, these techniques are time- and labor- consuming techniques, because special equipment is required for inspection, such as scaffolding or a truck mount aerial work platform. In this paper, a new thermography NDT technique, which is based on temperature gap appeared on the surface of structural members due to thermal insulation effect of the crack, is developed for detection of fatigue cracks. The practicability of the developed technique is demonstrated by the field experiments for highway steel bridges in service. Detectable crack size and factors such as measurement time, season or spatial resolution which influence crack detectability are investigated.

PARTITIONING INTERWELL TRACER TEST FOR NAPL SOURCE CHARACTERIZATION: A GENERAL OVERVIEW

EPA Science Inventory

Innovative and nondestructive characterization techniques have been developed to locate and quantify nonaqueous phase liquids (NAPLs) in the vadose and saturated zones in the subsurface environment. One such technique is the partitioning interwell tracer test (PITT). The PITT i...

Non-Destructive Techniques Based on Eddy Current Testing

PubMed Central

García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

2011-01-01

Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

Non-destructive techniques based on eddy current testing.

PubMed

García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

2011-01-01

Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future.

Regenerative particulate filter development

NASA Technical Reports Server (NTRS)

Descamp, V. A.; Boex, M. W.; Hussey, M. W.; Larson, T. P.

1972-01-01

Development, design, and fabrication of a prototype filter regeneration unit for regenerating clean fluid particle filter elements by using a backflush/jet impingement technique are reported. Development tests were also conducted on a vortex particle separator designed for use in zero gravity environment. A maintainable filter was designed, fabricated and tested that allows filter element replacement without any leakage or spillage of system fluid. Also described are spacecraft fluid system design and filter maintenance techniques with respect to inflight maintenance for the space shuttle and space station.

Aircraft propeller induced structure-borne noise

NASA Technical Reports Server (NTRS)

Unruh, James F.

1989-01-01

A laboratory-based test apparatus employing components typical of aircraft construction was developed that would allow the study of structure-borne noise transmission due to propeller induced wake/vortex excitation of in-wake structural appendages. The test apparatus was employed to evaluate several aircraft installation effects (power plant placement, engine/nacelle mass loading, and wing/fuselage attachment methods) and several structural response modifications for structure-borne noise control (the use of wing blocking mass/fuel, wing damping treaments, and tuned mechanical dampers). Most important was the development of in-flight structure-borne noise transmission detection techniques using a combination of ground-based frequency response function testing and in-flight structural response measurement. Propeller wake/vortex excitation simulation techniques for improved ground-based testing were also developed to support the in-flight structure-borne noise transmission detection development.

Diagnostics and Active Control of Aircraft Interior Noise

NASA Technical Reports Server (NTRS)

Fuller, C. R.

1998-01-01

This project deals with developing advanced methods for investigating and controlling interior noise in aircraft. The work concentrates on developing and applying the techniques of Near Field Acoustic Holography (NAH) and Principal Component Analysis (PCA) to the aircraft interior noise dynamic problem. This involves investigating the current state of the art, developing new techniques and then applying them to the particular problem being studied. The knowledge gained under the first part of the project was then used to develop and apply new, advanced noise control techniques for reducing interior noise. A new fully active control approach based on the PCA was developed and implemented on a test cylinder. Finally an active-passive approach based on tunable vibration absorbers was to be developed and analytically applied to a range of test structures from simple plates to aircraft fuselages.

Fault-tolerant onboard digital information switching and routing for communications satellites

NASA Technical Reports Server (NTRS)

Shalkhauser, Mary JO; Quintana, Jorge A.; Soni, Nitin J.; Kim, Heechul

1993-01-01

The NASA Lewis Research Center is developing an information-switching processor for future meshed very-small-aperture terminal (VSAT) communications satellites. The information-switching processor will switch and route baseband user data onboard the VSAT satellite to connect thousands of Earth terminals. Fault tolerance is a critical issue in developing information-switching processor circuitry that will provide and maintain reliable communications services. In parallel with the conceptual development of the meshed VSAT satellite network architecture, NASA designed and built a simple test bed for developing and demonstrating baseband switch architectures and fault-tolerance techniques. The meshed VSAT architecture and the switching demonstration test bed are described, and the initial switching architecture and the fault-tolerance techniques that were developed and tested are discussed.

A test technique for measuring lightning-induced voltages on aircraft electrical circuits

NASA Technical Reports Server (NTRS)

Walko, L. C.

1974-01-01

The development of a test technique used for the measurement of lightning-induced voltages in the electrical circuits of a complete aircraft is described. The resultant technique utilizes a portable device known as a transient analyzer capable of generating unidirectional current impulses similar to lightning current surges, but at a lower current level. A linear relationship between the magnitude of lightning current and the magnitude of induced voltage permitted the scaling up of measured induced values to full threat levels. The test technique was found to be practical when used on a complete aircraft.

Advanced ultrasonic techniques for nondestructive testing of austenitic and dissimilar welds in nuclear facilities

NASA Astrophysics Data System (ADS)

Juengert, Anne; Dugan, Sandra; Homann, Tobias; Mitzscherling, Steffen; Prager, Jens; Pudovikov, Sergey; Schwender, Thomas

2018-04-01

Austenitic stainless steel welds as well as dissimilar metal welds with nickel alloy filler material, used in safety relevant parts of nuclear power plants, still challenge the ultrasonic inspection. The weld material forms large oriented grains that lead, on the one hand, to high sound scattering and, on the other hand, to inhomogeneity and to the acoustic anisotropy of the weld structure. The ultrasonic wave fronts do not propagate linearly, as in ferritic weld joints, but along the curves, which depend on the specific grain structure of the weld. Due to the influence of these phenomena, it is difficult to analyze the inspection results and to classify the ultrasonic indications, which could be both from the weld geometry and from the material defects. A correct flaw sizing is not possible. In an ongoing research project, different techniques to improve the reliability of ultrasonic testing at these kinds of welds are investigated. In a first step (in the previous research project) two ultrasonic inspection techniques were developed and validated on plane test specimens with artificial and realistic flaws. In the ongoing project, these techniques are applied to circumferential pipe welds with longitudinal and transverse flaws. The technique developed at the Federal Institute for Materials Research and Testing (BAM) in Germany uses a combination of ray tracing and synthetic aperture focusing technique (SAFT). To investigate the unknown grain structure, the velocity distribution of weld-transmitting ultrasound waves is measured and used to model the weld by ray tracing. The second technique, developed at the Fraunhofer Institute for Nondestructive Testing (IZFP) in Germany, uses Sampling Phased Array (Full Matrix Capture) combined with the reverse phase matching (RPM) and the gradient elastic constant descent algorithm (GECDM). This inspection method is able to estimate the elastic constants of the columnar grains in the weld and offers an improvement of the reliability of ultrasonic testing through the correction of the sound field distortion. The unknown inhomogeneity and anisotropy are investigated using a reference indication and the special optimization algorithm. Both reconstruction techniques give quantitative inspection results and allow the defect sizing. They have been compared to conventional ultrasonic testing with techniques that are state of the art for components in nuclear power plants. The improvement will be quantified by the comparison of the probability of detection (POD) of each technique.

On the Feasibility of Multi-kHz Acquisition Rate Tomographic-PIV in Turbulent Flames

DTIC Science & Technology

2013-10-01

developed measurement technique used to acquire volumetric velocity field data in liquid and gaseous flows. The technique relies on line-of-sight...changes resulting from local heat-release may inhibit reconstruction and thereby render the technique infeasible. The objective of this study was to test...four CMOS cameras and a dual-cavity Nd:YAG laser was implemented to test the technique in a lifted turbulent jet flame. While the cameras were capable

Safety analysis in test facility design

NASA Astrophysics Data System (ADS)

Valk, A.; Jonker, R. J.

1990-09-01

The application of safety analysis techniques as developed in, for example nuclear and petrochemical industry, can be very beneficial in coping with the increasing complexity of modern test facility installations and their operations. To illustrate the various techniques available and their phasing in a project, an overview of the most commonly used techniques is presented. Two case studies are described: the hazard and operability study techniques and safety zoning in relation to the possible presence of asphyxiating atmospheres.

TESTING OF INDOOR RADON REDUCTION TECHNIQUES IN 19 MARYLAND HOUSES

EPA Science Inventory

The report gives results of testing of indoor radon reduction techniques in 19 existing houses in Maryland. The focus was on passive measures: various passive soil depressurization methods, where natural wind and temperature effects are utilized to develop suction in the system; ...

B.F. Skinner and the auditory inkblot: The rise and fall of the verbal summator as a projective technique.

PubMed

Rutherford, Alexandra

2003-11-01

Behaviorist B.F. Skinner is not typically associated with the fields of personality assessment or projective testing. However, early in his career Skinner developed an instrument he named the verbal summator, which, at one point, he referred to as a device for "snaring out complexes," much like an auditory analogue of the Rorschach inkblots. Skinner's interest in the projective potential of his technique was relatively short lived, but whereas he used the verbal summator to generate experimental data for his theory of verbal behavior, several other clinicians and researchers exploited this potential and adapted the verbal summator technique for both research and applied purposes. The idea of an auditory inkblot struck many as a useful innovation, and the verbal summator spawned the tautophone test, the auditory apperception test, and the Azzageddi test, among others. This article traces the origin, development, and eventual demise of the verbal summator as an auditory projective technique.

Electrical characterization of a Mapham inverter using pulse testing techniques

NASA Technical Reports Server (NTRS)

Baumann, E. D.; Myers, I. T.; Hammond, A. N.

1990-01-01

Electric power requirements for aerospace missions have reached megawatt power levels. Within the next few decades, it is anticipated that a manned lunar base, interplanetary travel, and surface exploration of the Martian surface will become reality. Several research and development projects aimed at demonstrating megawatt power level converters for space applications are currently underway at the NASA Lewis Research Center. Innovative testing techniques will be required to evaluate the components and converters, when developed, at their rated power in the absence of costly power sources, loads, and cooling systems. Facilities capable of testing these components and systems at full power are available, but their use may be cost prohibitive. The use of a multiple pulse testing technique is proposed to determine the electrical characteristics of large megawatt level power systems. Characterization of a Mapham inverter is made using the proposed technique and conclusions are drawn concerning its suitability as an experimental tool to evaluate megawatt level power systems.

Rethinking developmental toxicity testing: Evolution or revolution?

PubMed

Scialli, Anthony R; Daston, George; Chen, Connie; Coder, Prägati S; Euling, Susan Y; Foreman, Jennifer; Hoberman, Alan M; Hui, Julia; Knudsen, Thomas; Makris, Susan L; Morford, LaRonda; Piersma, Aldert H; Stanislaus, Dinesh; Thompson, Kary E

2018-06-01

Current developmental toxicity testing adheres largely to protocols suggested in 1966 involving the administration of test compound to pregnant laboratory animals. After more than 50 years of embryo-fetal development testing, are we ready to consider a different approach to human developmental toxicity testing? A workshop was held under the auspices of the Developmental and Reproductive Toxicology Technical Committee of the ILSI Health and Environmental Sciences Institute to consider how we might design developmental toxicity testing if we started over with 21st century knowledge and techniques (revolution). We first consider what changes to the current protocols might be recommended to make them more predictive for human risk (evolution). The evolutionary approach includes modifications of existing protocols and can include humanized models, disease models, more accurate assessment and testing of metabolites, and informed approaches to dose selection. The revolution could start with hypothesis-driven testing where we take what we know about a compound or close analog and answer specific questions using targeted experimental techniques rather than a one-protocol-fits-all approach. Central to the idea of hypothesis-driven testing is the concept that testing can be done at the level of mode of action. It might be feasible to identify a small number of key events at a molecular or cellular level that predict an adverse outcome and for which testing could be performed in vitro or in silico or, rarely, using limited in vivo models. Techniques for evaluating these key events exist today or are in development. Opportunities exist for refining and then replacing current developmental toxicity testing protocols using techniques that have already been developed or are within reach. © 2018 The Authors. Birth Defects Research Published by Wiley Periodicals, Inc.

Techniques for Developing Child Dummy Protection Reference Values. Event Report

DOT National Transportation Integrated Search

1996-10-01

The purpose of this report is to present background information and techniques : for developing protection reference values (PRV) to use with child dummies in : out-of-position (OOP) child/air bag interaction testing. Biomechanics experts : agree tha...

Advances in Testing Techniques for Digital Microfluidic Biochips

PubMed Central

Shukla, Vineeta; Hussin, Fawnizu Azmadi; Hamid, Nor Hisham; Zain Ali, Noohul Basheer

2017-01-01

With the advancement of digital microfluidics technology, applications such as on-chip DNA analysis, point of care diagnosis and automated drug discovery are common nowadays. The use of Digital Microfluidics Biochips (DMFBs) in disease assessment and recognition of target molecules had become popular during the past few years. The reliability of these DMFBs is crucial when they are used in various medical applications. Errors found in these biochips are mainly due to the defects developed during droplet manipulation, chip degradation and inaccuracies in the bio-assay experiments. The recently proposed Micro-electrode-dot Array (MEDA)-based DMFBs involve both fluidic and electronic domains in the micro-electrode cell. Thus, the testing techniques for these biochips should be revised in order to ensure proper functionality. This paper describes recent advances in the testing technologies for digital microfluidics biochips, which would serve as a useful platform for developing revised/new testing techniques for MEDA-based biochips. Therefore, the relevancy of these techniques with respect to testing of MEDA-based biochips is analyzed in order to exploit the full potential of these biochips. PMID:28749411

Advances in Testing Techniques for Digital Microfluidic Biochips.

PubMed

Shukla, Vineeta; Hussin, Fawnizu Azmadi; Hamid, Nor Hisham; Zain Ali, Noohul Basheer

2017-07-27

With the advancement of digital microfluidics technology, applications such as on-chip DNA analysis, point of care diagnosis and automated drug discovery are common nowadays. The use of Digital Microfluidics Biochips (DMFBs) in disease assessment and recognition of target molecules had become popular during the past few years. The reliability of these DMFBs is crucial when they are used in various medical applications. Errors found in these biochips are mainly due to the defects developed during droplet manipulation, chip degradation and inaccuracies in the bio-assay experiments. The recently proposed Micro-electrode-dot Array (MEDA)-based DMFBs involve both fluidic and electronic domains in the micro-electrode cell. Thus, the testing techniques for these biochips should be revised in order to ensure proper functionality. This paper describes recent advances in the testing technologies for digital microfluidics biochips, which would serve as a useful platform for developing revised/new testing techniques for MEDA-based biochips. Therefore, the relevancy of these techniques with respect to testing of MEDA-based biochips is analyzed in order to exploit the full potential of these biochips.

Transonic flight flutter tests of a control surface utilizing an impedance response technique

NASA Technical Reports Server (NTRS)

Mirowitz, L. I.

1975-01-01

Transonic flight flutter tests of the XF3H-1 Demon Airplane were conducted utilizing a frequency response technique in which the oscillating rudder provides the means of system excitation. These tests were conducted as a result of a rudder flutter incident in the transonic speed range. The technique employed is presented including a brief theoretical development of basic concepts. Test data obtained during the flight are included and the method of interpretation of these data is indicated. This method is based on an impedance matching technique. It is shown that an artificial stabilizing device, such as a damper, may be incorporated in the system for test purposes without complicating the interpretation of the test results of the normal configuration. Data are presented which define the margin of stability introduced to the originally unstable rudder by design changes which involve higher control system stiffness and external damper. It is concluded that this technique of flight flutter testing is a feasible means of obtaining flutter stability information in flight.

Manufacturing Process Developments for Regeneratively-Cooled Channel Wall Rocket Nozzles

NASA Technical Reports Server (NTRS)

Gradl, Paul; Brandsmeier, Will

2016-01-01

Regeneratively cooled channel wall nozzles incorporate a series of integral coolant channels to contain the coolant to maintain adequate wall temperatures and expand hot gas providing engine thrust and specific impulse. NASA has been evaluating manufacturing techniques targeting large scale channel wall nozzles to support affordability of current and future liquid rocket engine nozzles and thrust chamber assemblies. The development of these large scale manufacturing techniques focus on the liner formation, channel slotting with advanced abrasive water-jet milling techniques and closeout of the coolant channels to replace or augment other cost reduction techniques being evaluated for nozzles. NASA is developing a series of channel closeout techniques including large scale additive manufacturing laser deposition and explosively bonded closeouts. A series of subscale nozzles were completed evaluating these processes. Fabrication of mechanical test and metallography samples, in addition to subscale hardware has focused on Inconel 625, 300 series stainless, aluminum alloys as well as other candidate materials. Evaluations of these techniques are demonstrating potential for significant cost reductions for large scale nozzles and chambers. Hot fire testing is planned using these techniques in the future.

Techniques for the Installation of Internal Fiber Optic Instrumentation on an 11-Inch Hybrid Motor Test Bed

NASA Technical Reports Server (NTRS)

Cornelius, Michael; Smartt, Ziba; Henrie, Vaughn; Johnson, Mont

2003-01-01

The recent developments in Fabry-Perot fiber optic instruments have resulted in accurate transducers with some of the physical characteristics required for use in obtaining internal data from solid rocket motors. These characteristics include small size, non-electrical excitation, and immunity to electro-magnetic interference. These transducers have not been previously utilized in this environment due to the high temperatures typically encountered. A series of tests were conducted using a 1 1-Inch Hybrid test bed to develop installation techniques that will allow the fiber optic instruments to survive and obtain data for a short period of time following the motor ignition. The installation methods developed during this test series have the potential to allow data to be acquired in the motor chamber, propellant bore, and nozzle during the ignition transient. These measurements would prove to be very useful in the characterization of current motor designs and provide insight into the requirements for further refinements. The process of developing these protective methods and the installation techniques used to apply them is summarized.

Molecular Modeling in Drug Design for the Development of Organophosphorus Antidotes/Prophylactics.

DTIC Science & Technology

1986-06-01

multidimensional statistical QSAR analysis techniques to suggest new structures for synthesis and evaluation. C. Application of quantum chemical techniques to...compounds for synthesis and testing for antidotal potency. E. Use of computer-assisted methods to determine the steric constraints at the active site...modeling techniques to model the enzyme acetylcholinester-se. H. Suggestion of some novel compounds for synthesis and testing for reactivating

Modeling Student Software Testing Processes: Attitudes, Behaviors, Interventions, and Their Effects

ERIC Educational Resources Information Center

Buffardi, Kevin John

2014-01-01

Effective software testing identifies potential bugs and helps correct them, producing more reliable and maintainable software. As software development processes have evolved, incremental testing techniques have grown in popularity, particularly with introduction of test-driven development (TDD). However, many programmers struggle to adopt TDD's…

TESTING OF A 20-METER SOLAR SAIL SYSTEM

NASA Technical Reports Server (NTRS)

Gaspar, J. L.; Behun, V.; Mann, T.; Murphy D.; Macy, B.

2005-01-01

This paper describes the structural dynamic tests conducted in-vacuum on the Scalable Square Solar Sail (S(sup 4)) System 20-meter test article developed by ATK Space Systems as part of a ground demonstrator system development program funded by NASA's In-Space Propulsion program1-3. These tests were conducted for the purpose of validating analytical models that would be required by a flight test program to predict in space performance4. Specific tests included modal vibration tests on the solar sail system in a 1 Torr vacuum environment using various excitation locations and techniques including magnetic excitation at the sail quadrant corners, piezoelectric stack actuation at the mast roots, spreader bar excitation at the mast tips, and bi-morph piezoelectric patch actuation on the sail cords. The excitation methods were evaluated for their suitability to in-vacuum ground testing and their traceability to the development of on-orbit flight test techniques. The solar sail masts were also tested in ambient atmospheric conditions and these results are also discussed.

TESTING OF A 20-METER SOLAR SAIL SYSTEM

NASA Technical Reports Server (NTRS)

Gaspar, Jim L.; Behun, Vaughan; Mann, Troy; Murphy, Dave; Macy, Brian

2005-01-01

This paper describes the structural dynamic tests conducted in-vacuum on the Scalable Square Solar Sail (S(sup 4)) System 20-meter test article developed by ATK Space Systems as part of a ground demonstrator system development program funded by NASA's In-Space Propulsion program. These tests were conducted for the purpose of validating analytical models that would be required by a flight test program to predict in space performance. Specific tests included modal vibration tests on the solar sail system in a 1 Torr vacuum environment using various excitation locations and techniques including magnetic excitation at the sail quadrant corners, piezoelectric stack actuation at the mast roots, spreader bar excitation at the mast tips, and bi-morph piezoelectric patch actuation on the sail cords. The excitation methods are evaluated for their suitability to in-vacuum ground testing and their traceability to the development of on-orbit flight test techniques. The solar sail masts were also tested in ambient atmospheric conditions and these results are also discussed.

Future experimental needs to support applied aerodynamics - A transonic perspective

NASA Technical Reports Server (NTRS)

Gloss, Blair B.

1992-01-01

Advancements in facilities, test techniques, and instrumentation are needed to provide data required for the development of advanced aircraft and to verify computational methods. An industry survey of major users of wind tunnel facilities at Langley Research Center (LaRC) was recently carried out to determine future facility requirements, test techniques, and instrumentation requirements; results from this survey are reflected in this paper. In addition, areas related to transonic testing at LaRC which are either currently being developed or are recognized as needing improvements are discussed.

Scaling Techniques for Combustion Device Random Vibration Predictions

NASA Technical Reports Server (NTRS)

Kenny, R. J.; Ferebee, R. C.; Duvall, L. D.

2016-01-01

This work presents compares scaling techniques that can be used for prediction of combustion device component random vibration levels with excitation due to the internal combustion dynamics. Acceleration and unsteady dynamic pressure data from multiple component test programs are compared and normalized per the two scaling approaches reviewed. Two scaling technique are reviewed and compared against the collected component test data. The first technique is an existing approach developed by Barrett, and the second technique is an updated approach new to this work. Results from utilizing both techniques are presented and recommendations about future component random vibration prediction approaches are given.

Technique development for conducting mechanical tests to study the pore formation process in case of material fracture

NASA Astrophysics Data System (ADS)

Magomedova, D. K.; Efimov, M. A.; Murashkin, M. Yu.

2018-05-01

The main purpose of this work was the development of an experimental technique for search and analysis of pore formation in the presented material. Geometry of the samples, the procedure of experiment and processing the samples for investigation were developed.

Summary of CPAS Gen II Parachute Analysis

NASA Technical Reports Server (NTRS)

Morris, Aaron L.; Bledsoe, Kristin J.; Fraire, Usbaldo, Jr.; Moore, James W.; Olson, Leah M.; Ray, Eric

2011-01-01

The Orion spacecraft is currently under development by NASA and Lockheed Martin. Like Apollo, Orion will use a series of parachutes to slow its descent and splashdown safely. The Orion parachute system, known as the CEV Parachute Assembly System (CPAS), is being designed by NASA, the Engineering and Science Contract Group (ESCG), and Airborne Systems. The first generation (Gen I) of CPAS testing consisted of thirteen tests and was executed in the 2007-2008 timeframe. The Gen I tests provided an initial understanding of the CPAS parachutes. Knowledge gained from Gen I testing was used to plan the second generation of testing (Gen II). Gen II consisted of six tests: three singleparachute tests, designated as Main Development Tests, and three Cluster Development Tests. Gen II required a more thorough investigation into parachute performance than Gen I. Higher fidelity instrumentation, enhanced analysis methods and tools, and advanced test techniques were developed. The results of the Gen II test series are being incorporated into the CPAS design. Further testing and refinement of the design and model of parachute performance will occur during the upcoming third generation of testing (Gen III). This paper will provide an overview of the developments in CPAS analysis following the end of Gen I, including descriptions of new tools and techniques as well as overviews of the Gen II tests.

Aerodynamic force measurement on a large-scale model in a short duration test facility

NASA Astrophysics Data System (ADS)

Tanno, H.; Kodera, M.; Komuro, T.; Sato, K.; Takahasi, M.; Itoh, K.

2005-03-01

A force measurement technique has been developed for large-scale aerodynamic models with a short test time. The technique is based on direct acceleration measurements, with miniature accelerometers mounted on a test model suspended by wires. Measuring acceleration at two different locations, the technique can eliminate oscillations from natural vibration of the model. The technique was used for drag force measurements on a 3m long supersonic combustor model in the HIEST free-piston driven shock tunnel. A time resolution of 350μs is guaranteed during measurements, whose resolution is enough for ms order test time in HIEST. To evaluate measurement reliability and accuracy, measured values were compared with results from a three-dimensional Navier-Stokes numerical simulation. The difference between measured values and numerical simulation values was less than 5%. We conclude that this measurement technique is sufficiently reliable for measuring aerodynamic force within test durations of 1ms.

V/STOL and STOL ground effects and testing techniques

NASA Technical Reports Server (NTRS)

Kuhn, R. E.

1987-01-01

The ground effects associated with V/STOL operation were examined and an effort was made to develop the equipment and testing techniques needed for that understanding. Primary emphasis was on future experimental programs in the 40 x 80 and the 80 x 120 foot test sections and in the outdoor static test stand associated with these facilities. The commonly used experimental techniques are reviewed and data obtained by various techniques are compared with each other and with available estimating methods. These reviews and comparisons provide insight into the limitations of past studies and the testing techniques used and identify areas where additional work is needed. The understanding of the flow mechanics involved in hovering and in transition in and out of ground effect is discussed. The basic flow fields associated with hovering, transition and STOL operation of jet powered V/STOL aircraft are depicted.

Parameter estimation techniques and application in aircraft flight testing

NASA Technical Reports Server (NTRS)

1974-01-01

Technical papers presented at the symposium by selected representatives from industry, universities, and various Air Force, Navy, and NASA installations are given. The topics covered include the newest developments in identification techniques, the most recent flight-test experience, and the projected potential for the near future.

Developing Multiple Choice Tests: Tips & Techniques

ERIC Educational Resources Information Center

McCowan, Richard J.

1999-01-01

Item writing is a major responsibility of trainers. Too often, qualified staff who prepare lessons carefully and teach conscientiously use inadequate tests that do not validly reflect the true level of trainee achievement. This monograph describes techniques for constructing multiple-choice items that measure student performance accurately. It…

Nonlinear Modeling of Joint Dominated Structures

NASA Technical Reports Server (NTRS)

Chapman, J. M.

1990-01-01

The development and verification of an accurate structural model of the nonlinear joint-dominated NASA Langley Mini-Mast truss are described. The approach is to characterize the structural behavior of the Mini-Mast joints and struts using a test configuration that can directly measure the struts' overall stiffness and damping properties, incorporate this data into the structural model using the residual force technique, and then compare the predicted response with empirical data taken by NASA/LaRC during the modal survey tests of the Mini-Mast. A new testing technique, referred to as 'link' testing, was developed and used to test prototype struts of the Mini-Masts. Appreciable nonlinearities including the free-play and hysteresis were demonstrated. Since static and dynamic tests performed on the Mini-Mast also exhibited behavior consistent with joints having free-play and hysteresis, nonlinear models of the Mini-Mast were constructed and analyzed. The Residual Force Technique was used to analyze the nonlinear model of the Mini-Mast having joint free-play and hysteresis.

Evaluation of various thrust calculation techniques on an F404 engine

NASA Technical Reports Server (NTRS)

Ray, Ronald J.

1990-01-01

In support of performance testing of the X-29A aircraft at the NASA-Ames, various thrust calculation techniques were developed and evaluated for use on the F404-GE-400 engine. The engine was thrust calibrated at NASA-Lewis. Results from these tests were used to correct the manufacturer's in-flight thrust program to more accurately calculate thrust for the specific test engine. Data from these tests were also used to develop an independent, simplified thrust calculation technique for real-time thrust calculation. Comparisons were also made to thrust values predicted by the engine specification model. Results indicate uninstalled gross thrust accuracies on the order of 1 to 4 percent for the various in-flight thrust methods. The various thrust calculations are described and their usage, uncertainty, and measured accuracies are explained. In addition, the advantages of a real-time thrust algorithm for flight test use and the importance of an accurate thrust calculation to the aircraft performance analysis are described. Finally, actual data obtained from flight test are presented.

Ground test challenges in the development of the Space Shuttle orbiter auxiliary power unit

NASA Technical Reports Server (NTRS)

Chaffee, N. H.; Lance, R. J.; Weary, D. P.

1984-01-01

A conventional aircraft hydraulic system design approach was selected to provide fluid power for the Space Shuttle Orbiter. Developing the power unit, known as the Auxiliary Power Unit (APU), to drive the hydraulic pumps presented a major technological challenge. A small, high speed turbine drive unit powered by catalytically decomposed hydrazine and operating in the pulse mode was selected to meet the requirement. Because of limitations of vendor test facilities, significant portions of the development, flight qualification, and postflight anomaly testing of the Orbiter APU were accomplished at the Johnson Space Center (JSC) test facilities. This paper discusses the unique requirements of attitude, gravity forces, pressure profiles, and thermal environments which had to be satisfied by the APU, and presents the unique test facility and simulation techniques employed to meet the ground test requirements. In particular, the development of the zero-g lubrication system, the development of necessary APU thermal control techniques, the accomplishment of integrated systems tests, and the postflight investigation of the APU lube oil cooler behavior are discussed.

Techniques for developing child dummy protection reference values : event report

DOT National Transportation Integrated Search

1996-10-01

The purpose of this report is to present background information and techniques for developing protection reference values (PRV) to use with child dummies in out-of-position (OOP) child/air bag interaction testing. This report summarizes the literatur...

E-Learning Development Process for Operating System Course in Vocational School

NASA Astrophysics Data System (ADS)

Tuna, J. R.; Manoppo, C. T. M.; Kaparang, D. R.; Mewengkang, A.

2018-02-01

This development research aims to produce learning media in the form of E- Learning media using Edmodo which is interesting, efficient and effective on the subjects of operating system for students of class X TKJ in SMKN 3 Manado. The development model used was developed by S. Thiagarajan et al., Often known as the Four-D model, but this research only uses (define, design, and develop). Trial of the product is done twice (limited and wide). The experimental design used was the before-after experimental design. Data collection techniques used are interview techniques, questionnaires, and tests. The analytical technique used in this development research is descriptive qualitative. These include analysis of attractiveness test, efficiency and effectiveness of E-Learning media using Edmodo. The media attractiveness test was measured using a student response questionnaire. Media efficiency test was obtained through interviews of researchers with operating system subjects teachers and students of class X TKJ 1 at SMKN 3 Manado. While the media effectiveness test obtained from student learning outcomes before and after applying E-Learning media using Edomodo. Then tested by paired sample t test formula. After the media was piloted on the subject of trials (limited and broad), and the results show that E-Learning media using Edmodo is interesting, efficient and effective. It is shown on average student response score of 88.15% with very interesting interpretation. While the average value of student learning outcomes increased from 76.33 to 82.93. The results of differential test (paired sample t-test) the value of t = 11 217 ≥ ttable = 2,045 with significant value = 0.000 <α = 0.050 showing the media E -Learning using Edmodo is effective.

Forecasting in foodservice: model development, testing, and evaluation.

PubMed

Miller, J L; Thompson, P A; Orabella, M M

1991-05-01

This study was designed to develop, test, and evaluate mathematical models appropriate for forecasting menu-item production demand in foodservice. Data were collected from residence and dining hall foodservices at Ohio State University. Objectives of the study were to collect, code, and analyze the data; develop and test models using actual operation data; and compare forecasting results with current methods in use. Customer count was forecast using deseasonalized simple exponential smoothing. Menu-item demand was forecast by multiplying the count forecast by a predicted preference statistic. Forecasting models were evaluated using mean squared error, mean absolute deviation, and mean absolute percentage error techniques. All models were more accurate than current methods. A broad spectrum of forecasting techniques could be used by foodservice managers with access to a personal computer and spread-sheet and database-management software. The findings indicate that mathematical forecasting techniques may be effective in foodservice operations to control costs, increase productivity, and maximize profits.

Society of Flight Test Engineers, Annual Symposium, 21st, Garden Grove, CA, Aug. 6-10, 1990, Proceedings

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

Not Available

1990-01-01

The present conference on flight testing encompasses avionics, flight-testing programs, technologies for flight-test predictions and measurements, testing tools, analysis methods, targeting techniques, and flightline testing. Specific issues addressed include flight testing of a digital terrain-following system, a digital Doppler rate-of-descent indicator, a high-technology testbed, a low-altitude air-refueling flight-test program, techniques for in-flight frequency-response testing for helicopters, limit-cycle oscillation and flight-flutter testing, and the research flight test of a scaled unmanned air vehicle. Also addressed are AV-8B V/STOL performance analysis, incorporating pilot-response time in failure-case testing, the development of pitot static flightline testing, targeting techniques for ground-based hover testing, a low-profilemore » microsensor for aerodynamic pressure measurement, and the use of a variable-capacitance accelerometer for flight-test measurements.« less

AGARD Flight Test Techniques Series. Volume 12. The Principles of Flight Test Assessment of Flight-Safety-Critical Systems in Helicopters (Les Principes de l’Evaluation, dans le Cadre des Essais en Vol, des Systemes Indispensables a la Securite de Vol des Helicopteres)

DTIC Science & Technology

1994-08-01

AGARD-AG-300 Vol. 12 04 ADVISORY GROUP FOR AEROSPACE RESEARCH & DEVELOPMENT 7 RUE ANCELLE, 92200 NEUILLY-SUR-SEINE, FRANCE AUG 0195 AGARDograph 300...AGARD Flight Test Techniques Series Volume 12 on The Principles of Flight Test Assessment of Flight-Safety-Critical Systems in Helicopters (Les...and Availability on Back Cover AGARD-AG-300 Vol. 12 ADVISORY GROUP FOR AEROSPACE RESEARCH & DEVELOPMENT 7 RUE ANCELLE, 92200 NEUILLY-SUR-SEINE, FRANCE

"MSTGen": Simulated Data Generator for Multistage Testing

ERIC Educational Resources Information Center

Han, Kyung T.

2013-01-01

Multistage testing, or MST, was developed as an alternative to computerized adaptive testing (CAT) for applications in which it is preferable to administer a test at the level of item sets (i.e., modules). As with CAT, the simulation technique in MST plays a critical role in the development and maintenance of tests. "MSTGen," a new MST…

Aging aircraft NDI Development and Demonstration Center (AANC): An overview. [nondestructive inspection

NASA Technical Reports Server (NTRS)

Walter, Patrick L.

1992-01-01

A major center with emphasis on validation of nondestructive inspection (NDI) techniques for aging aircraft, the Aging Aircraft NDI Development and Demonstration Center (AANC), has been funded by the FAA at Sandia National Laboratories. The Center has been assigned specific tasks in developing techniques for the nondestructive inspection of static engine parts, assessing inspection reliability (POD experiments), developing testbeds for NDI validation, maintaining a FAA library of characterized aircraft structural test specimens, and leasing a hangar to house a high flight cycle transport aircraft for use as a full scale test bed.

Comparative evaluation between anatomic and non-anatomic lateral ligament reconstruction techniques in the ankle joint: A computational study.

PubMed

Purevsuren, Tserenchimed; Batbaatar, Myagmarbayar; Khuyagbaatar, Batbayar; Kim, Kyungsoo; Kim, Yoon Hyuk

2018-03-12

Biomechanical studies have indicated that the conventional non-anatomic reconstruction techniques for lateral ankle sprain (LAS) tend to restrict subtalar joint motion compared to intact ankle joints. Excessive restriction in subtalar motion may lead to chronic pain, functional difficulties, and development of osteoarthritis. Therefore, various anatomic surgical techniques to reconstruct both the anterior talofibular and calcaneofibular ligaments have been introduced. In this study, ankle joint stability was evaluated using multibody computational ankle joint model to assess two new anatomic reconstruction and three popular non-anatomic reconstruction techniques. An LAS injury, three popular non-anatomic reconstruction models (Watson-Jones, Evans, and Chrisman-Snook), and two common types of anatomic reconstruction models were developed based on the intact ankle model. The stability of ankle in both talocrural and subtalar joint were evaluated under anterior drawer test (150 N anterior force), inversion test (3 Nm inversion moment), internal rotational test (3 Nm internal rotation moment), and the combined loading test (9 Nm inversion and internal moment as well as 1800 N compressive force). Our overall results show that the two anatomic reconstruction techniques were superior to the non-anatomic reconstruction techniques in stabilizing both talocrural and subtalar joints. Restricted subtalar joint motion, which mainly observed in Watson-Jones and Chrisman-Snook techniques, was not shown in the anatomical reconstructions. Evans technique was beneficial for subtalar joint as it does not restrict subtalar motion, though Evans technique was insufficient for restoring talocrural joint inversion. The anatomical reconstruction techniques best recovered ankle stability.

Safe Driving Knowledge Dissemination and Testing Techniques. Volume II: Final Report.

ERIC Educational Resources Information Center

McKnight, James; Green, Molly A.

In order to determine the effectiveness of improved information dissemination and assessment techniques in reducing highway accidents, a set of seven targeted driver license manuals and tests were developed for the following groups of drivers: new drivers, youthful drivers, renewal applicants, older drivers, traffic violators, accident repeaters,…

Safe Driving Knowledge Dissemination and Testing Techniques. Volume 1: General Findings.

ERIC Educational Resources Information Center

McKnight, James; Green, Molly A.

In order to determine the effectiveness of improved information dissemination and assessment techniques in reducing highway accidents, a set of seven targeted driver license manuals and tests were developed for the following groups of drivers: new drivers, youthful drivers, renewal applicants, older drivers, traffic violators, accident repeaters,…

Space Shuttle stability and control flight test techniques

NASA Technical Reports Server (NTRS)

Cooke, D. R.

1980-01-01

A unique approach for obtaining vehicle aerodynamic characteristics during entry has been developed for the Space Shuttle. This is due to the high cost of Shuttle testing, the need to open constraints for operational flights, and the fact that all flight regimes are flown starting with the first flight. Because of uncertainties associated with predicted aerodynamic coefficients, nine flight conditions have been identified at which control problems could occur. A detailed test plan has been developed for testing at these conditions and is presented. Due to limited testing, precise computer initiated maneuvers are implemented. These maneuvers are designed to optimize the vehicle motion for determining aerodynamic coefficients. Special sensors and atmospheric measurements are required to provide stability and control flight data during an entire entry. The techniques employed in data reduction are proven programs developed and used at NASA/DFRC.

Development of a Process for a High Capacity Arc Heater Production of Silicon for Solar Arrays

NASA Technical Reports Server (NTRS)

Reed, W. H.

1979-01-01

A program was established to develop a high temperature silicon production process using existing electric arc heater technology. Silicon tetrachloride and a reductant (sodium) are injected into an arc heated mixture of hydrogen and argon. Under these high temperature conditions, a very rapid reaction is expected to occur and proceed essentially to completion, yielding silicon and gaseous sodium chloride. Techniques for high temperature separation and collection were developed. Included in this report are: test system preparation; testing; injection techniques; kinetics; reaction demonstration; conclusions; and the project status.

Note: development of high speed confocal 3D profilometer.

PubMed

Ang, Kar Tien; Fang, Zhong Ping; Tay, Arthur

2014-11-01

A high-speed confocal 3D profilometer based on the chromatic confocal technology and spinning Nipkow disk technique has been developed and tested. It can measure a whole surface topography by taking only one image that requires less than 0.3 s. Surface height information is retrieved based on the ratios of red, green, and blue color information. A new vector projection technique has developed to enhance the vertical resolution of the measurement. The measurement accuracy of the prototype system has been verified via different test samples.

Reservoir engineering applications for development and exploitation of geothermal fields in the Philippines

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

Vasquez, N.C.; Sarmiento, Z.F.

1986-07-01

After a geothermal well is completed, several tests and downhole measurements are conducted to help evaluate the subsurface fluid and reservoir properties intersected. From these tests, a conceptual model of the well can be developed by integrating data from the various parts of the field. This paper presents the completion techniques applied in geothermal wells, as well as the role of reservoir engineering science in delineating a field for development. Monitoring techniques and other reservoir engineering aspects of a field under exploitation are also discussed, with examples from the Philippines.

Flight test experience with high-alpha control system techniques on the F-14 airplane

NASA Technical Reports Server (NTRS)

Gera, J.; Wilson, R. J.; Enevoldson, E. K.; Nguyen, L. T.

1981-01-01

Improved handling qualities of fighter aircraft at high angles of attack can be provided by various stability and control augmentation techniques. NASA and the U.S. Navy are conducting a joint flight demonstration of these techniques on an F-14 airplane. This paper reports on the flight test experience with a newly designed lateral-directional control system which suppresses such high angle of attack handling qualities problems as roll reversal, wing rock, and directional divergence while simultaneously improving departure/spin resistance. The technique of integrating a piloted simulation into the flight program was used extensively in this program. This technique had not been applied previously to high angle of attack testing and required the development of a valid model to simulate the test airplane at extremely high angles of attack.

Orion Boiler Plate Airdrop Test System

NASA Technical Reports Server (NTRS)

Machin, Ricardo A.; Evans, Carol T.

2013-01-01

On the 29th of February 2012 the Orion Capsule Parachute Assembly System (CPAS) project attempted to perform an airdrop test of a boilerplate test article for the second time. The first attempt (Cluster Development Test 2, July 2008) to deliver a similar boilerplate from a C-17 using the Low Velocity Air Drop (LVAD) technique resulted in the programmer parachute failing to properly inflate, the test article failing to achieve the desired test initiation conditions, and the test article a total loss. This paper will pick up where the CDT-2 failure investigation left off, describing the test technique that was adopted, and outline the modeling that was performed to gain confidence that the second attempt would be successful. The second boiler plate test (Cluster Development Test 3-3) was indeed a complete success and has subsequently been repeated several times, allowing the CPAS project to proceed with the full scale system level development testing required to integrate the hardware to the first Entry Flight Test vehicle as well as go into the Critical Design Review with minimum risk and a mature design.

Leak testing and repair of fusion devices

NASA Astrophysics Data System (ADS)

Kozman, T. A.

1983-06-01

The leak testing, reporting and vacuum leak repair techniques of the MPTF yin-yang number one magnet system, the world's largest superconducting magnet system, are discussed. Based on this experience, techniques are developed for testing and repairing leaks on the 42 MPTF-B magnets. The leak hunting techniques for the yin-yang magnet systems were applied to two helium circuits (the coil bundle and guard vacuum; both require helium flow for magnet cooldown). Additionally, during MPTF-B operation there are warm water plasma shields and piping that require leak checking.

Developments in flow visualization methods for flight research

NASA Technical Reports Server (NTRS)

Holmes, Bruce J.; Obara, Clifford J.; Manuel, Gregory S.; Lee, Cynthia C.

1990-01-01

With the introduction of modern airplanes utilizing laminar flow, flow visualization has become an important diagnostic tool in determining aerodynamic characteristics such as surface flow direction and boundary-layer state. A refinement of the sublimating chemical technique has been developed to define both the boundary-layer transition location and the transition mode. In response to the need for flow visualization at subsonic and transonic speeds and altitudes above 20,000 feet, the liquid crystal technique has been developed. A third flow visualization technique that has been used is infrared imaging, which offers non-intrusive testing over a wide range of test conditions. A review of these flow visualization methods and recent flight results is presented for a variety of modern aircraft and flight conditions.

Novel Optical Technique Developed and Tested for Measuring Two-Point Velocity Correlations in Turbulent Flows

NASA Technical Reports Server (NTRS)

Zimmerli, Gregory A.; Goldburg, Walter I.

2002-01-01

A novel technique for characterizing turbulent flows was developed and tested at the NASA Glenn Research Center. The work is being done in collaboration with the University of Pittsburgh, through a grant from the NASA Microgravity Fluid Physics Program. The technique we are using, Homodyne Correlation Spectroscopy (HCS), is a laser-light-scattering technique that measures the Doppler frequency shift of light scattered from microscopic particles in the fluid flow. Whereas Laser Doppler Velocimetry gives a local (single-point) measurement of the fluid velocity, the HCS technique measures correlations between fluid velocities at two separate points in the flow at the same instant of time. Velocity correlations in the flow field are of fundamental interest to turbulence researchers and are of practical importance in many engineering applications, such as aeronautics.

Development of a Three-Tier Test to Assess Misconceptions about Simple Electric Circuits

ERIC Educational Resources Information Center

Pesman, Haki; Eryilmaz, Ali

2010-01-01

The authors aimed to propose a valid and reliable diagnostic instrument by developing a three-tier test on simple electric circuits. Based on findings from the interviews, open-ended questions, and the related literature, the test was developed and administered to 124 high school students. In addition to some qualitative techniques for…

A quantitative investigation of the fracture pump-in/flowback test

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

Plahn, S.V.; Nolte, K.G.; Thompson, L.G.

1997-02-01

Fracture-closure pressure is an important parameter for fracture treatment design and evaluation. The pump-in/flowback (PIFB) test is frequently used to estimate its magnitude. The test is attractive because bottomhole pressures (BHP`s) during flowback develop a distinct and repeatable signature. This is in contrast to the pump-in/shut-in test, where strong indications of fracture closure are rarely seen. Various techniques are used to extract closure pressure from the flowback-pressure response. Unfortunately, these techniques give different estimates for closure pressure, and their theoretical bases are not well established. The authors present results that place the PIFB test on a firmer foundation. A numericalmore » model is used to simulate the PIFB test and glean physical mechanisms contributing to the response. On the basis of their simulation results, they propose interpretation techniques that give better estimates of closure pressure than existing techniques.« less

Transverse vibration technique to identify deteriorated wood floor systems

Treesearch

R.J. Ross; X. Wang; M.O. Hunt; L.A. Soltis

2002-01-01

The Forest Products Laboratory, USDA Forest Service, has been developing nondestructive evaluation (NDE) techniques to identify degradation of wood in structures and the performance characteristics that remain in the structure. This work has focused on using dynamic testing techniques, particularly stress wave and ultrasonic transmission NDE techniques for both...

Monitoring genetic damage to ecosystems from hazardous waste

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

Anderson, S.L.

1992-03-01

Applications of ecological toxicity testing to hazardous waste management have increased dramatically over the last few years, resulting in a greater awareness of the need for improved biomonitoring techniques. Our laboratory is developing advanced techniques to assess the genotoxic effects of environmental contamination on ecosystems. We have developed a novel mutagenesis assay using the nematode Caenorhabditis elegans, which is potentially applicable for multimedia studies in soil, sediment, and water. In addition, we are conducting validation studies of a previously developed anaphase aberration test that utilizes sea urchin embryos. Other related efforts include field validation studies of the new tests, evaluationmore » of their potential ecological relevance, and analysis of their sensitivity relative to that of existing toxicity tests that assess only lethal effects, rather than genetic damage.« less

Short Duration Base Heating Test Improvements

NASA Technical Reports Server (NTRS)

Bender, Robert L.; Dagostino, Mark G.; Engel, Bradley A.; Engel, Carl D.

1999-01-01

Significant improvements have been made to a short duration space launch vehicle base heating test technique. This technique was first developed during the 1960's to investigate launch vehicle plume induced convective environments. Recent improvements include the use of coiled nitrogen buffer gas lines upstream of the hydrogen / oxygen propellant charge tubes, fast acting solenoid valves, stand alone gas delivery and data acquisition systems, and an integrated model design code. Technique improvements were successfully demonstrated during a 2.25% scale X-33 base heating test conducted in the NASA/MSFC Nozzle Test Facility in early 1999. Cost savings of approximately an order of magnitude over previous tests were realized due in large part to these improvements.

Miniature penetrator (MinPen) acceleration recorder development test

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

Franco, R.J.; Platzbecker, M.R.

1998-08-01

The Telemetry Technology Development Department at Sandia National Laboratories actively develops and tests acceleration recorders for penetrating weapons. This new acceleration recorder (MinPen) utilizes a microprocessor-based architecture for operational flexibility while maintaining electronics and packaging techniques developed over years of penetrator testing. MinPen has been demonstrated to function in shock environments up to 20,000 Gs. The MinPen instrumentation development has resulted in a rugged, versatile, miniature acceleration recorder and is a valuable tool for penetrator testing in a wide range of applications.

The Development and Hover Test Application of a Projection Moire Interferometry Blade Displacement Measurement System

NASA Technical Reports Server (NTRS)

Sekula, Martin K.

2012-01-01

Projection moir interferometry (PMI) was employed to measure blade deflections during a hover test of a generic model-scale rotor in the NASA Langley 14x22 subsonic wind tunnel s hover facility. PMI was one of several optical measurement techniques tasked to acquire deflection and flow visualization data for a rotor at several distinct heights above a ground plane. Two of the main objectives of this test were to demonstrate that multiple optical measurement techniques can be used simultaneously to acquire data and to identify and address deficiencies in the techniques. Several PMI-specific technical challenges needed to be addressed during the test and in post-processing of the data. These challenges included developing an efficient and accurate calibration method for an extremely large (65 inch) height range; automating the analysis of the large amount of data acquired during the test; and developing a method to determinate the absolute displacement of rotor blades without a required anchor point measurement. The results indicate that the use of a single-camera/single-projector approach for the large height range reduced the accuracy of the PMI system compared to PMI systems designed for smaller height ranges. The lack of the anchor point measurement (due to a technical issue with one of the other measurement techniques) limited the ability of the PMI system to correctly measure blade displacements to only one of the three rotor heights tested. The new calibration technique reduced the data required by 80 percent while new post-processing algorithms successfully automated the process of locating rotor blades in images, determining the blade quarter chord location, and calculating the blade root and blade tip heights above the ground plane.

Improvement of Railroad Roller Bearing Test Procedures & Development of Roller Bearing Diagnostic Techniques. Volume 2.

DOT National Transportation Integrated Search

1982-04-01

A comprehensive review of existing basic diagnostic techniques applicable to the railcar roller bearing defect and failure problem was made. Of the potentially feasible diagnostic techniques identified, high frequency vibration was selected for exper...

Three-dimensional printing for restoration of the donor face: A new digital technique tested and used in the first facial allotransplantation patient in Finland.

PubMed

Mäkitie, A A; Salmi, M; Lindford, A; Tuomi, J; Lassus, P

2016-12-01

Prosthetic mask restoration of the donor face is essential in current facial transplant protocols. The aim was to develop a new three-dimensional (3D) printing (additive manufacturing; AM) process for the production of a donor face mask that fulfilled the requirements for facial restoration after facial harvest. A digital image of a single test person's face was obtained in a standardized setting and subjected to three different image processing techniques. These data were used for the 3D modeling and printing of a donor face mask. The process was also tested in a cadaver setting and ultimately used clinically in a donor patient after facial allograft harvest. and Conclusions: All the three developed and tested techniques enabled the 3D printing of a custom-made face mask in a timely manner that is almost an exact replica of the donor patient's face. This technique was successfully used in a facial allotransplantation donor patient. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Ground Data System Risk Mitigation Techniques for Faster, Better, Cheaper Missions

NASA Technical Reports Server (NTRS)

Catena, John J.; Saylor, Rick; Casasanta, Ralph; Weikel, Craig; Powers, Edward I. (Technical Monitor)

2000-01-01

With the advent of faster, cheaper, and better missions, NASA Projects acknowledged that a higher level of risk was inherent and accepted with this approach. It was incumbent however upon each component of the Project whether spacecraft, payload, launch vehicle, or ground data system to ensure that the mission would nevertheless be an unqualified success. The Small Explorer (SMEX) program's ground data system (GDS) team developed risk mitigation techniques to achieve these goals starting in 1989. These techniques have evolved through the SMEX series of missions and are practiced today under the Triana program. These techniques are: (1) Mission Team Organization--empowerment of a closeknit ground data system team comprising system engineering, software engineering, testing, and flight operations personnel; (2) Common Spacecraft Test and Operational Control System--utilization of the pre-launch spacecraft integration system as the post-launch ground data system on-orbit command and control system; (3) Utilization of operations personnel in pre-launch testing--making the flight operations team an integrated member of the spacecraft testing activities at the beginning of the spacecraft fabrication phase; (4) Consolidated Test Team--combined system, mission readiness and operations testing to optimize test opportunities with the ground system and spacecraft; and (5). Reuse of Spacecraft, Systems and People--reuse of people, software and on-orbit spacecraft throughout the SMEX mission series. The SMEX ground system development approach for faster, cheaper, better missions has been very successful. This paper will discuss these risk management techniques in the areas of ground data system design, implementation, test, and operational readiness.

Solid State Audio/Speech Processor Analysis.

DTIC Science & Technology

1980-03-01

techniques. The techniques were demonstrated to be worthwhile in an efficient realtime AWR system. Finally, microprocessor architectures were designed to...do not include custom chip development, detailed hardware design , construction or testing. ITTDCD is very encouraged by the results obtained in this...California, Berkley, was responsible for furnishing the simulation data of OD speech analysis techniques and for the design and development of the hardware OD

Adaptive wall technology for minimization of wall interferences in transonic wind tunnels

NASA Technical Reports Server (NTRS)

Wolf, Stephen W. D.

1988-01-01

Modern experimental techniques to improve free air simulations in transonic wind tunnels by use of adaptive wall technology are reviewed. Considered are the significant advantages of adaptive wall testing techniques with respect to wall interferences, Reynolds number, tunnel drive power, and flow quality. The application of these testing techniques relies on making the test section boundaries adjustable and using a rapid wall adjustment procedure. A historical overview shows how the disjointed development of these testing techniques, since 1938, is closely linked to available computer support. An overview of Adaptive Wall Test Section (AWTS) designs shows a preference for use of relatively simple designs with solid adaptive walls in 2- and 3-D testing. Operational aspects of AWTS's are discussed with regard to production type operation where adaptive wall adjustments need to be quick. Both 2- and 3-D data are presented to illustrate the quality of AWTS data over the transonic speed range. Adaptive wall technology is available for general use in 2-D testing, even in cryogenic wind tunnels. In 3-D testing, more refinement of the adaptive wall testing techniques is required before more widespread use can be planned.

Application of High Speed Digital Image Correlation in Rocket Engine Hot Fire Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.; Schmidt, Tim

2016-01-01

Hot fire testing of rocket engine components and rocket engine systems is a critical aspect of the development process to understand performance, reliability and system interactions. Ground testing provides the opportunity for highly instrumented development testing to validate analytical model predictions and determine necessary design changes and process improvements. To properly obtain discrete measurements for model validation, instrumentation must survive in the highly dynamic and extreme temperature application of hot fire testing. Digital Image Correlation has been investigated and being evaluated as a technique to augment traditional instrumentation during component and engine testing providing further data for additional performance improvements and cost savings. The feasibility of digital image correlation techniques were demonstrated in subscale and full scale hotfire testing. This incorporated a pair of high speed cameras to measure three-dimensional, real-time displacements and strains installed and operated under the extreme environments present on the test stand. The development process, setup and calibrations, data collection, hotfire test data collection and post-test analysis and results are presented in this paper.

Development of a technique for inflight jet noise simulation. I, II

NASA Technical Reports Server (NTRS)

Clapper, W. S.; Stringas, E. J.; Mani, R.; Banerian, G.

1976-01-01

Several possible noise simulation techniques were evaluated, including closed circuit wind tunnels, free jets, rocket sleds and high speed trains. The free jet technique was selected for demonstration and verification. The first paper describes the selection and development of the technique and presents results for simulation and in-flight tests of the Learjet, F106, and Bertin Aerotrain. The second presents a theoretical study relating the two sets of noise signatures. It is concluded that the free jet simulation technique provides a satisfactory assessment of in-flight noise.

Single-strain-gage force/stiffness buckling prediction techniques on a hat-stiffened panel

NASA Technical Reports Server (NTRS)

Hudson, Larry D.; Thompson, Randolph C.

1991-01-01

Predicting the buckling characteristics of a test panel is necessary to ensure panel integrity during a test program. A single-strain-gage buckling prediction method was developed on a hat-stiffened, monolithic titanium buckling panel. The method is an adaptation of the original force/stiffness method which requires back-to-back gages. The single-gage method was developed because the test panel did not have back-to-back gages. The method was used to predict buckling loads and temperatures under various heating and loading conditions. The results correlated well with a finite element buckling analysis. The single-gage force/stiffness method was a valid real-time and post-test buckling prediction technique.

Evaluation Techniques for Individualized Instruction: Development and Formative Testing.

ERIC Educational Resources Information Center

Bedient, Douglas; And Others

1986-01-01

Steps used in the formative evaluation of a project designed to incorporate self-instructional materials in an introductory zoology course included techniques which: (1) involved colleagues in the material development; (2) assessed relevant student characteristics, expectations, and evaluations; and (3) were used in the examinations. (MBR)

A Dual-Line Detection Rayleigh Scattering Diagnostic Technique for the Combustion of Hydrocarbon Fuels and Filtered UV Rayleigh Scattering for Gas Velocity Measurements

NASA Technical Reports Server (NTRS)

Otugen, M. Volkan

1997-01-01

Non-intrusive techniques for the dynamic measurement of gas flow properties such as density, temperature and velocity, are needed in the research leading to the development of new generation high-speed aircraft. Accurate velocity, temperature and density data obtained in ground testing and in-flight measurements can help understand the flow physics leading to transition and turbulence in supersonic, high-altitude flight. Such non-intrusive measurement techniques can also be used to study combustion processes of hydrocarbon fuels in aircraft engines. Reliable, time and space resolved temperature measurements in various combustor configurations can lead to a better understanding of high temperature chemical reaction dynamics thus leading to improved modeling and better prediction of such flows. In view of this, a research program was initiated at Polytechnic University's Aerodynamics Laboratory with support from NASA Lewis Research Center through grants NAG3-1301 and NAG3-1690. The overall objective of this program has been to develop laser-based, non-contact, space- and time-resolved temperature and velocity measurement techniques. In the initial phase of the program a ND:YAG laser-based dual-line Rayleigh scattering technique was developed and tested for the accurate measurement of gas temperature in the presence of background laser glare. Effort was next directed towards the development of a filtered, spectrally-resolved Rayleigh/Mie scattering technique with the objective of developing an interferometric method for time-frozen velocity measurements in high-speed flows utilizing the uv line of an ND:YAG laser and an appropriate molecular absorption filter. This effort included both a search for an appropriate filter material for the 266 nm laser line and the development and testing of several image processing techniques for the fast processing of Fabry-Perot images for velocity and temperature information. Finally, work was also carried out for the development of a new laser-based strain-rate and vorticity technique for the time-resolved measurement of vorticity and strain-rates in turbulent flows.

Direct Field Acoustic Testing

NASA Technical Reports Server (NTRS)

Larkin, Paul; Goldstein, Bob

2008-01-01

This paper presents an update to the methods and procedures used in Direct Field Acoustic Testing (DFAT). The paper will discuss some of the recent techniques and developments that are currently being used and the future publication of a reference standard. Acoustic testing using commercial sound system components is becoming a popular and cost effective way of generating a required acoustic test environment both in and out of a reverberant chamber. This paper will present the DFAT test method, the usual setup and procedure and the development and use of a closed-loop, narrow-band control system. Narrow-band control of the acoustic PSD allows all standard techniques and procedures currently used in random control to be applied to acoustics and some examples are given. The paper will conclude with a summary of the development of a standard practice guideline that is hoped to be available in the first quarter of next year.

Validation and Verification of LADEE Models and Software

NASA Technical Reports Server (NTRS)

Gundy-Burlet, Karen

2013-01-01

The Lunar Atmosphere Dust Environment Explorer (LADEE) mission will orbit the moon in order to measure the density, composition and time variability of the lunar dust environment. The ground-side and onboard flight software for the mission is being developed using a Model-Based Software methodology. In this technique, models of the spacecraft and flight software are developed in a graphical dynamics modeling package. Flight Software requirements are prototyped and refined using the simulated models. After the model is shown to work as desired in this simulation framework, C-code software is automatically generated from the models. The generated software is then tested in real time Processor-in-the-Loop and Hardware-in-the-Loop test beds. Travelling Road Show test beds were used for early integration tests with payloads and other subsystems. Traditional techniques for verifying computational sciences models are used to characterize the spacecraft simulation. A lightweight set of formal methods analysis, static analysis, formal inspection and code coverage analyses are utilized to further reduce defects in the onboard flight software artifacts. These techniques are applied early and often in the development process, iteratively increasing the capabilities of the software and the fidelity of the vehicle models and test beds.

Air-to-air radar flight testing

NASA Astrophysics Data System (ADS)

Scott, Randall E.

1988-06-01

This volume in the AGARD Flight Test Techniques Series describes flight test techniques, flight test instrumentation, ground simulation, data reduction and analysis methods used to determine the performance characteristics of a modern air-to-air (a/a) radar system. Following a general coverage of specification requirements, test plans, support requirements, development and operational testing, and management information systems, the report goes into more detailed flight test techniques covering a/a radar capabilities of: detection, manual acquisition, automatic acquisition, tracking a single target, and detection and tracking of multiple targets. There follows a section on additional flight test considerations such as electromagnetic compatibility, electronic countermeasures, displays and controls, degraded and backup modes, radome effects, environmental considerations, and use of testbeds. Other sections cover ground simulation, flight test instrumentation, and data reduction and analysis. The final sections deal with reporting and a discussion of considerations for the future and how they may affect radar flight testing.

Research and Development of High-performance Explosives

PubMed Central

Cornell, Rodger; Wrobel, Erik; Anderson, Paul E.

2016-01-01

Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance tests to verify theoretical calculations. small-scale For newly developed formulations, the process begins with small-scale mixes, thermal testing, and impact and friction sensitivity. Only then do subsequent larger scale formulations proceed to detonation testing, which will be covered in this paper. Recent advances in characterization techniques have led to unparalleled precision in the characterization of early-time evolution of detonations. The new technique of photo-Doppler velocimetry (PDV) for the measurement of detonation pressure and velocity will be shared and compared with traditional fiber-optic detonation velocity and plate-dent calculation of detonation pressure. In particular, the role of aluminum in explosive formulations will be discussed. Recent developments led to the development of explosive formulations that result in reaction of aluminum very early in the detonation product expansion. This enhanced reaction leads to changes in the detonation velocity and pressure due to reaction of the aluminum with oxygen in the expanding gas products. PMID:26966969

A novel method of testing the shear strength of thick honeycomb composites

NASA Technical Reports Server (NTRS)

Hodge, A. J.; Nettles, A. T.

1991-01-01

Sandwich composites of aluminum and glass/phenolic honeycomb core were tested for shear strength before and after impact damage. The assessment of shear strength was performed in two ways; by four point bend testing of sandwich beams and by a novel double lap shear (DLS) test. This testing technique was developed so smaller specimens could be used, thus making the use of common lab scale fabrication and testing possible. The two techniques yielded similar data. The DLS test gave slightly lower shear strength values of the two methods but were closer to the supplier's values for shear strength.

Ground Vibration Test Planning and Pre-Test Analysis for the X-33 Vehicle

NASA Technical Reports Server (NTRS)

Bedrossian, Herand; Tinker, Michael L.; Hidalgo, Homero

2000-01-01

This paper describes the results of the modal test planning and the pre-test analysis for the X-33 vehicle. The pre-test analysis included the selection of the target modes, selection of the sensor and shaker locations and the development of an accurate Test Analysis Model (TAM). For target mode selection, four techniques were considered, one based on the Modal Cost technique, one based on Balanced Singular Value technique, a technique known as the Root Sum Squared (RSS) method, and a Modal Kinetic Energy (MKE) approach. For selecting sensor locations, four techniques were also considered; one based on the Weighted Average Kinetic Energy (WAKE), one based on Guyan Reduction (GR), one emphasizing engineering judgment, and one based on an optimum sensor selection technique using Genetic Algorithm (GA) search technique combined with a criteria based on Hankel Singular Values (HSV's). For selecting shaker locations, four techniques were also considered; one based on the Weighted Average Driving Point Residue (WADPR), one based on engineering judgment and accessibility considerations, a frequency response method, and an optimum shaker location selection based on a GA search technique combined with a criteria based on HSV's. To evaluate the effectiveness of the proposed sensor and shaker locations for exciting the target modes, extensive numerical simulations were performed. Multivariate Mode Indicator Function (MMIF) was used to evaluate the effectiveness of each sensor & shaker set with respect to modal parameter identification. Several TAM reduction techniques were considered including, Guyan, IRS, Modal, and Hybrid. Based on a pre-test cross-orthogonality checks using various reduction techniques, a Hybrid TAM reduction technique was selected and was used for all three vehicle fuel level configurations.

New Directions in Special Education.

ERIC Educational Resources Information Center

Jones, Reginald L., Ed.

The text presents a collection of articles dealing with new research and developments relevant to special education. Discussions include automation, teaching machines, programed instruction, psycholinguistic testing, differential diagnosis, language development and testing, and remediation techniques. Other topics consider measurement of behavior,…

Recent advances in testing of microsphere drug delivery systems.

PubMed

Andhariya, Janki V; Burgess, Diane J

2016-01-01

This review discusses advances in the field of microsphere testing. In vitro release-testing methods such as sample and separate, dialysis membrane sacs and USP apparatus IV have been used for microspheres. Based on comparisons of these methods, USP apparatus IV is currently the method of choice. Accelerated in vitro release tests have been developed to shorten the testing time for quality control purposes. In vitro-in vivo correlations using real-time and accelerated release data have been developed, to minimize the need to conduct in vivo performance evaluation. Storage stability studies have been conducted to investigate the influence of various environmental factors on microsphere quality throughout the product shelf life. New tests such as the floating test and the in vitro wash-off test have been developed along with advancement in characterization techniques for other physico-chemical parameters such as particle size, drug content, and thermal properties. Although significant developments have been made in microsphere release testing, there is still a lack of guidance in this area. Microsphere storage stability studies should be extended to include microspheres containing large molecules. An agreement needs to be reached on the use of particle sizing techniques to avoid inconsistent data. An approach needs to be developed to determine total moisture content of microspheres.

Recommended techniques for effective maintainability. A continuous improvement initiative of the NASA Reliability and Maintainability Steering Committee

NASA Technical Reports Server (NTRS)

1994-01-01

This manual presents a series of recommended techniques that can increase overall operational effectiveness of both flight and ground based NASA systems. It provides a set of tools that minimizes risk associated with: (1) restoring failed functions (both ground and flight based); (2) conducting complex and highly visible maintenance operations; and (3) sustaining a technical capability to support the NASA mission using aging equipment or facilities. It considers (1) program management - key elements of an effective maintainability effort; (2) design and development - techniques that have benefited previous programs; (3) analysis and test - quantitative and qualitative analysis processes and testing techniques; and (4) operations and operational design techniques that address NASA field experience. This document is a valuable resource for continuous improvement ideas in executing the systems development process in accordance with the NASA 'better, faster, smaller, and cheaper' goal without compromising safety.

Alignment of a multilayer-coated imaging system using extreme ultraviolet Foucault and Ronchi interferometric testing

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

Ray-Chaudhuri, A.K.; Ng, W.; Cerrina, F.

1995-11-01

Multilayer-coated imaging systems for extreme ultraviolet (EUV) lithography at 13 nm represent a significant challenge for alignment and characterization. The standard practice of utilizing visible light interferometry fundamentally provides an incomplete picture since this technique fails to account for phase effects induced by the multilayer coating. Thus the development of optical techniques at the functional EUV wavelength is required. We present the development of two EUV optical tests based on Foucault and Ronchi techniques. These relatively simple techniques are extremely sensitive due to the factor of 50 reduction in wavelength. Both techniques were utilized to align a Mo--Si multilayer-coated Schwarzschildmore » camera. By varying the illumination wavelength, phase shift effects due to the interplay of multilayer coating and incident angle were uniquely detected. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}« less

Transient excitation and data processing techniques employing the fast fourier transform for aeroelastic testing

NASA Technical Reports Server (NTRS)

Jennings, W. P.; Olsen, N. L.; Walter, M. J.

1976-01-01

The development of testing techniques useful in airplane ground resonance testing, wind tunnel aeroelastic model testing, and airplane flight flutter testing is presented. Included is the consideration of impulsive excitation, steady-state sinusoidal excitation, and random and pseudorandom excitation. Reasons for the selection of fast sine sweeps for transient excitation are given. The use of the fast fourier transform dynamic analyzer (HP-5451B) is presented, together with a curve fitting data process in the Laplace domain to experimentally evaluate values of generalized mass, model frequencies, dampings, and mode shapes. The effects of poor signal to noise ratios due to turbulence creating data variance are discussed. Data manipulation techniques used to overcome variance problems are also included. The experience is described that was gained by using these techniques since the early stages of the SST program. Data measured during 747 flight flutter tests, and SST, YC-14, and 727 empennage flutter model tests are included.

Progress in speckle-shift strain measurement

NASA Technical Reports Server (NTRS)

Lant, Christian T.; Barranger, John P.; Oberle, Lawrence G.; Greer, Lawrence C., III

1991-01-01

The Instrumentation and Control Technology Division of the Lewis Research Center has been developing an in-house capability to make one dimensional and two dimensional optical strain measurements on high temperature test specimens. The measurements are based on a two-beam speckle-shift technique. The development of composite materials for use in high temperature applications is generating interest in using the speckle-shift technique to measure strains on small diameter fibers and wires of various compositions. The results of preliminary speckle correlation tests on wire and fiber specimens are covered, and the advanced system currently under development is described.

Endurance test of a 30-CM-diameter engineering model ion thruster. Task 12: Investigation of thin-film erosion monitors for ion thrusters

NASA Technical Reports Server (NTRS)

Beattie, J. R.

1983-01-01

An investigation of short term measurement techniques for predicting the wearout of ion thrusters resulting from sputter erosion damage is described. The previously established laminar thin film techniques to provide high precision erosion rate data. However, the erosion rates obtained using this technique are generally substantially higher than those obtained during long term endurance tests (by virtue of the as deposited nature of the thin films), so that the results must be interpreted in a relative sense. Absolute measurements can be performed using a new masked substrate arrangement which was developed during this study. This new technique provides a means for estimating the lifetimes of critical discharge chamber components based on direct measurements of sputter erosion depths obtained during short duration (10 hour) tests. The method enables the effects on lifetime of thruster design and operating parameters to be inferred without the investment of the time and capital required to conduct long term (1000 hour) endurance tests. Results obtained using the direct measurement technique are shown to agree with sputter erosion depths calculated for the plasma conditions of the test and also with lifetest results. The direct measurement approach is shown to be applicable to both mercury and argon discharge plasma environments and should be useful in estimating the lifetimes of inert gas and extended performance mercury ion thrusters presently under development.

Mosquito Control Techniques Developed for the US Military and an Update on the AMCA

USDA-ARS?s Scientific Manuscript database

Scientists at the USDA Center for Medical, Agricultural and Veterinary Entomology developed and field tested novel techniques to protect deployed military troops from diseases transmitted by mosquitoes and sand flies. Methods that proved to be very effective included (1) novel military personal prot...

Characterization of Regular Wave, Irregular Wave, and Large-Amplitude Wave Group Kinematics in an Experimental Basin

DTIC Science & Technology

2011-02-01

seakeeping was the transient wave technique, developed analytically by Davis and Zarnick (1964). At the David Taylor Model Basin, Davis and Zarnick, and...Gersten and Johnson (1969) applied the transient wave technique to regular wave model experiments for heave and pitch, at zero forward speed. These...tests demonstrated a potential reduction by an order of magnitude of the total necessary testing time. The transient wave technique was also applied to

Identification of Low Order Equivalent System Models From Flight Test Data

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

2000-01-01

Identification of low order equivalent system dynamic models from flight test data was studied. Inputs were pilot control deflections, and outputs were aircraft responses, so the models characterized the total aircraft response including bare airframe and flight control system. Theoretical investigations were conducted and related to results found in the literature. Low order equivalent system modeling techniques using output error and equation error parameter estimation in the frequency domain were developed and validated on simulation data. It was found that some common difficulties encountered in identifying closed loop low order equivalent system models from flight test data could be overcome using the developed techniques. Implications for data requirements and experiment design were discussed. The developed methods were demonstrated using realistic simulation cases, then applied to closed loop flight test data from the NASA F-18 High Alpha Research Vehicle.

PSK Shift Timing Information Detection Using Image Processing and a Matched Filter

DTIC Science & Technology

2009-09-01

phase shifts are enhanced.  Develop, design, and test the resulting phase shift identification scheme. xx  Develop, design, and test an optional...and the resulting phase shift identification algorithm is investigated for SNR levels in the range -2dB to 12 dB. Detection performances are derived...test the resulting phase shift identification scheme.  Develop, design, and test an optional analysis window overlapping technique to improve phase

Free-flight measurement technique in the free-piston high-enthalpy shock tunnel.

PubMed

Tanno, H; Komuro, T; Sato, K; Fujita, K; Laurence, S J

2014-04-01

A novel multi-component force-measurement technique has been developed and implemented at the impulse facility JAXA-HIEST, in which the test model is completely unrestrained during the test and thus experiences free-flight conditions for a period on the order of milliseconds. Advantages over conventional free-flight techniques include the complete absence of aerodynamic interference from a model support system and less variation in model position and attitude during the test itself. A miniature on-board data recorder, which was a key technology for this technique, was also developed in order to acquire and store the measured data. The technique was demonstrated in a HIEST wind-tunnel test campaign in which three-component aerodynamic force measurement was performed on a blunted cone of length 316 mm, total mass 19.75 kg, and moment of inertia 0.152 kgm(2). During the test campaign, axial force, normal forces, and pitching moment coefficients were obtained at angles of attack from 14° to 32° under two conditions: H0 = 4 MJ/kg, P0 = 14 MPa; and H0 = 16 MJ/kg, P0 = 16 MPa. For the first, low-enthalpy condition, the test flow was considered a perfect gas; measurements were thus directly compared with those obtained in a conventional blow-down wind tunnel (JAXA-HWT2) to evaluate the accuracy of the technique. The second test condition was a high-enthalpy condition in which 85% of the oxygen molecules were expected to be dissociated; high-temperature real-gas effects were therefore evaluated by comparison with results obtained in perfect-gas conditions. The precision of the present measurements was evaluated through an uncertainty analysis, which showed the aerodynamic coefficients in the HIEST low enthalpy test agreeing well with those of JAXA-HWT2. The pitching-moment coefficient, however, showed significant differences between low- and high-enthalpy tests. These differences are thought to result from high-temperature real-gas effects.

Free-flight measurement technique in the free-piston high-enthalpy shock tunnel

NASA Astrophysics Data System (ADS)

Tanno, H.; Komuro, T.; Sato, K.; Fujita, K.; Laurence, S. J.

2014-04-01

A novel multi-component force-measurement technique has been developed and implemented at the impulse facility JAXA-HIEST, in which the test model is completely unrestrained during the test and thus experiences free-flight conditions for a period on the order of milliseconds. Advantages over conventional free-flight techniques include the complete absence of aerodynamic interference from a model support system and less variation in model position and attitude during the test itself. A miniature on-board data recorder, which was a key technology for this technique, was also developed in order to acquire and store the measured data. The technique was demonstrated in a HIEST wind-tunnel test campaign in which three-component aerodynamic force measurement was performed on a blunted cone of length 316 mm, total mass 19.75 kg, and moment of inertia 0.152 kgm2. During the test campaign, axial force, normal forces, and pitching moment coefficients were obtained at angles of attack from 14° to 32° under two conditions: H0 = 4 MJ/kg, P0 = 14 MPa; and H0 = 16 MJ/kg, P0 = 16 MPa. For the first, low-enthalpy condition, the test flow was considered a perfect gas; measurements were thus directly compared with those obtained in a conventional blow-down wind tunnel (JAXA-HWT2) to evaluate the accuracy of the technique. The second test condition was a high-enthalpy condition in which 85% of the oxygen molecules were expected to be dissociated; high-temperature real-gas effects were therefore evaluated by comparison with results obtained in perfect-gas conditions. The precision of the present measurements was evaluated through an uncertainty analysis, which showed the aerodynamic coefficients in the HIEST low enthalpy test agreeing well with those of JAXA-HWT2. The pitching-moment coefficient, however, showed significant differences between low- and high-enthalpy tests. These differences are thought to result from high-temperature real-gas effects.

Reading: Tests and Assessment Techniques. Second Edition. United Kingdom Reading Association Teaching of Reading Monograph Series.

ERIC Educational Resources Information Center

Pumfrey, Peter D.

The second edition of this British publication provides details of recent developments in the assessment of reading attainments and the analysis of reading processes. The book begins with a description of various types of reading tests and assessment techniques with consideration given to the purposes for which normative, criterion-referenced, and…

Electromagnetic environmental criteria for US Army missile systems - EMC, EMR, EMI, EMP, ESD, and lightning

NASA Astrophysics Data System (ADS)

Ponds, Charles D.; Knaur, James A.

1988-01-01

This paper presents the design and test requirements in developing an electromagnetic compatibility missile system. Environmental levels are presented for electromagnetic radiation hazards, electromagnetic radiation operational, electrostatic discharge, lightning, and electromagnetic pulse (nuclear). Testing techniques and facility capabilities are presented for research and development testing of missile systems.

The Development of Modal Testing Technology for Wind Turbines: A Historical Perspective

NASA Technical Reports Server (NTRS)

James, George H., III; Carne, Thomas G.

2007-01-01

Wind turbines are very large, flexible structures, with aerodynamic forces on the rotating blades producing periodic forces with frequencies at the harmonics of the rotation frequency. Due to design consideration, these rotational frequencies are comparable to the modal frequencies; thus avoiding resonant conditions is a critical consideration. Consequently, predicting and experimentally validating the modal frequencies of wind turbines has been important to their successful design and operation. Performing modal tests on flexible structures over 120 meters tall is a substantial challenge, which has inspired innovative developments in modal test technology. A further trial to the analyst and experimentalist is that the modal frequencies are dependent on the turbine rotation speed, so testing a parked turbine does not fully validate the analytical predictions. The history and development of this modal testing technology will be reviewed, showing historical tests and techniques, ranging from two-meter to 100-meter turbines for both parked and rotating tests. The NExT (Natural Excitation Technique) was developed in the 1990's, as a predecessor to OMA to overcome these challenges. We will trace the difficulties and successes of wind turbine modal testing over the past twenty-five years from 1982 to the present.

Laboratory-scale uranium RF plasma confinement experiments

NASA Technical Reports Server (NTRS)

Roman, W. C.

1976-01-01

An experimental investigation was conducted using 80 kW and 1.2 MW RF induction heater facilities to aid in developing the technology necessary for designing a self-critical fissioning uranium plasma core reactor. Pure uranium hexafluoride (UF6) was injected into argon-confined, steady-state, RF-heated plasmas in different uranium plasma confinement tests to investigate the characteristics of plamas core nuclear reactors. The objectives were: (1) to confine as high a density of uranium vapor as possible within the plasma while simultaneously minimizing the uranium compound wall deposition; (2) to develop and test materials and handling techniques suitable for use with high-temperature, high-pressure gaseous UF6; and (3) to develop complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma and residue deposited on the test chamber components. In all tests, the plasma was a fluid-mechanically-confined vortex-type contained within a fused-silica cylindrical test chamber. The test chamber peripheral wall was 5.7 cm ID by 10 cm long.

Demonstrating Hemostasis with a Student-Designed Prothrombin Time Test

ERIC Educational Resources Information Center

Fardy, Richard Wiley

1978-01-01

Describes a blood coagulation test developed by two high school biology students. Although the test lacks some precision, results indicate that the technique is comparable to standard methods used in laboratories. (MA)

Post-test navigation data analysis techniques for the shuttle ALT

NASA Technical Reports Server (NTRS)

1975-01-01

Postflight test analysis data processing techniques for shuttle approach and landing tests (ALT) navigation data are defined. Postfight test processor requirements are described along with operational and design requirements, data input requirements, and software test requirements. The postflight test data processing is described based on the natural test sequence: quick-look analysis, postflight navigation processing, and error isolation processing. Emphasis is placed on the tradeoffs that must remain open and subject to analysis until final definition is achieved in the shuttle data processing system and the overall ALT plan. A development plan for the implementation of the ALT postflight test navigation data processing system is presented. Conclusions are presented.

Real-time in-flight engine performance and health monitoring techniques for flight research application

NASA Technical Reports Server (NTRS)

Ray, Ronald J.; Hicks, John W.; Wichman, Keith D.

1991-01-01

Procedures for real time evaluation of the inflight health and performance of gas turbine engines and related systems were developed to enhance flight test safety and productivity. These techniques include the monitoring of the engine, the engine control system, thrust vectoring control system health, and the detection of engine stalls. Real time performance techniques were developed for the determination and display of inflight thrust and for aeroperformance drag polars. These new methods were successfully shown on various research aircraft at NASA-Dryden. The capability of NASA's Western Aeronautical Test Range and the advanced data acquisition systems were key factors for implementation and real time display of these methods.

Optimizing Department of Defense Acquisition Development Test and Evaluation Scheduling

DTIC Science & Technology

2015-06-01

CPM Critical Path Method DOD Department of Defense DT&E development test and evaluation EMD engineering and manufacturing development GAMS...these, including the Program Evaluation Review Technique (PERT), the Critical Path Method ( CPM ), and the resource- constrained project-scheduling...problem (RCPSP). These are of particular interest to this thesis as the current scheduling method uses elements of the PERT/ CPM , and the test

Development of an external ceramic insulation for the space shuttle orbiter

NASA Technical Reports Server (NTRS)

Tanzilli, R. A. (Editor)

1972-01-01

The development and evaluation of a family of reusable external insulation systems for use on the space shuttle orbiter is discussed. The material development and evaluation activities are described. Additional information is provided on the development of an analytical micromechanical model of the reusable insulation and the development of techniques for reducing the heat transfer. Design data on reusable insulation systems and test techniques used for design data generation are included.

Noncontaminating technique for making holes in existing process systems

NASA Technical Reports Server (NTRS)

Hecker, T. P.; Czapor, H. P.; Giordano, S. M.

1972-01-01

Technique is developed for making cleanly-contoured holes in assembled process systems without introducing chips or other contaminants into system. Technique uses portable equipment and does not require dismantling of system. Method was tested on Inconel, stainless steel, ASTMA-53, and Hastelloy X in all positions.

Current status and some future test directions for the U.S. National Transonic Facility

NASA Technical Reports Server (NTRS)

Gloss, Blair B.

1992-01-01

The construction of the National Transonic Facility was completed in September 1982 and the start-up and checkout of the tunnel systems were performed over the following two years. In August 1984, the facility was declared operational for final checkout of cryogenic instrumentation and control systems, and for the aerodynamics calibration and testing to commence. Since 1984 several operational problems have been identified and successfully solved which is demonstrated by the fact that the facility has operated the last year with no significant facility down times. Also during this time period, development of test techniques and instrumentation has continued. This paper will review some of the recent test techniques and instrumentation developments, and will briefly review the status of the facility.

Basic antenna transmitting characteristics using an extrapolation range measurement technique at a millimeter-wave band at NMIJ/AIST.

PubMed

Yamamoto, Tetsuya

2007-06-01

A novel test fixture operating at a millimeter-wave band using an extrapolation range measurement technique was developed at the National Metrology Institute of Japan (NMIJ). Here I describe the measurement system using a Q-band test fixture. I measured the relative insertion loss as a function of antenna separation distance and observed the effects of multiple reflections between the antennas. I also evaluated the antenna gain at 33 GHz using the extrapolation technique.

Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

NASA Technical Reports Server (NTRS)

Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

2001-01-01

Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate ('dynamic fatigue') testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rate in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

NASA Technical Reports Server (NTRS)

Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

2001-01-01

Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate (dynamic fatigue) testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rates in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

Attachment techniques for high temperature strain

NASA Astrophysics Data System (ADS)

Wnuk, Steve P., Jr.

1993-01-01

Attachment methods for making resistive strain measurements to 2500 F were studied. A survey of available strain gages and attachment techniques was made, and the results are compiled for metal and carbon composite test materials. A theoretical analysis of strain transfer into a bonded strain gage was made, and the important physical parameters of the strain transfer medium, the ceramic matrix, were identified. A pull tester to measure pull-out tests on commonly used strain gage cements indicated that all cements tested displayed adequate strength for good strain transfer. Rokide flame sprayed coatings produced significantly stronger bonds than ceramic cements. An in-depth study of the flame spray process produced simplified installation procedures which also resulted in greater reliability and durability. Application procedures incorporating improvements made during this program are appended to the report. Strain gages installed on carbon composites, Rene' 41, 316 stainless steel, and TZM using attachment techniques developed during this program were successfully tested to 2500 F. Photographs of installation techniques, test procedures, and graphs of the test data are included in this report.

Development and testing of incident detection algorithms. Vol. 2, research methodology and detailed results.

DOT National Transportation Integrated Search

1976-04-01

The development and testing of incident detection algorithms was based on Los Angeles and Minneapolis freeway surveillance data. Algorithms considered were based on times series and pattern recognition techniques. Attention was given to the effects o...

An Intraoperative β- Detecting Probe for Radio-Guided Surgery in Tumour Resection

NASA Astrophysics Data System (ADS)

Russomando, Andrea; Bellini, Fabio; Bocci, Valerio; Collamati, Francesco; De Lucia, Erika; Faccini, Riccardo; Marafini, Michela; Mattei, Ilaria; Chiodi, Giacomo; Patera, Vincenzo; Recchia, Luigi; Sarti, Alessio; Sciubba, Adalberto; Camillocci, Elena Solfaroli; Paramatti, Riccardo; Voena, Cecilia; Donnarumma, Raffaella; Mancini-Terracciano, Carlo; Morganti, Silvio

2016-10-01

The development of the β- based radio-guided surgery aims to extend the technique to those tumours where surgery is the only possible treatment and the assessment of the resection would most profit from the low background around the lesion, as for brain tumours. To validate the technique, prototypes of the intraoperative β- probe have been developed. This paper discusses the design details of one of the prototypes and its tests performed in laboratory. In such tests particular care has to be taken to reproduce the surgical field conditions. The tests showed that the prototype under study has 70% efficiency on electrons with an energy threshold at 540 keV, a point-like resolution of 2.8±0.1 mm, and a sensitivity to photons lower than 1%. The tests also demonstrated, with an innovative technique to produce specific phantoms, that 0.5 ml residuals can be safely identified in 1 s with tumor-non-tumor ratio equal to 10.

Test Driven Development: Lessons from a Simple Scientific Model

NASA Astrophysics Data System (ADS)

Clune, T. L.; Kuo, K.

2010-12-01

In the commercial software industry, unit testing frameworks have emerged as a disruptive technology that has permanently altered the process by which software is developed. Unit testing frameworks significantly reduce traditional barriers, both practical and psychological, to creating and executing tests that verify software implementations. A new development paradigm, known as test driven development (TDD), has emerged from unit testing practices, in which low-level tests (i.e. unit tests) are created by developers prior to implementing new pieces of code. Although somewhat counter-intuitive, this approach actually improves developer productivity. In addition to reducing the average time for detecting software defects (bugs), the requirement to provide procedure interfaces that enable testing frequently leads to superior design decisions. Although TDD is widely accepted in many software domains, its applicability to scientific modeling still warrants reasonable skepticism. While the technique is clearly relevant for infrastructure layers of scientific models such as the Earth System Modeling Framework (ESMF), numerical and scientific components pose a number of challenges to TDD that are not often encountered in commercial software. Nonetheless, our experience leads us to believe that the technique has great potential not only for developer productivity, but also as a tool for understanding and documenting the basic scientific assumptions upon which our models are implemented. We will provide a brief introduction to test driven development and then discuss our experience in using TDD to implement a relatively simple numerical model that simulates the growth of snowflakes. Many of the lessons learned are directly applicable to larger scientific models.

Development of one-step Loop-Mediated Isothermal Amplification (LAMP) for the detection of norovirus in oysters

USDA-ARS?s Scientific Manuscript database

The aim of this study was to develop a simple and rapid technique for detecting human norovirus (NoV). The loop-mediated isothermal amplification (LAMP) technique was evaluated and found to be sensitive, highly specific, and useful for routine oyster testing. Reverse transcription-LAMP (RT-LAMP) pri...

Free Flight Rotorcraft Flight Test Vehicle Technology Development

NASA Technical Reports Server (NTRS)

Hodges, W. Todd; Walker, Gregory W.

1994-01-01

A rotary wing, unmanned air vehicle (UAV) is being developed as a research tool at the NASA Langley Research Center by the U.S. Army and NASA. This development program is intended to provide the rotorcraft research community an intermediate step between rotorcraft wind tunnel testing and full scale manned flight testing. The technologies under development for this vehicle are: adaptive electronic flight control systems incorporating artificial intelligence (AI) techniques, small-light weight sophisticated sensors, advanced telepresence-telerobotics systems and rotary wing UAV operational procedures. This paper briefly describes the system's requirements and the techniques used to integrate the various technologies to meet these requirements. The paper also discusses the status of the development effort. In addition to the original aeromechanics research mission, the technology development effort has generated a great deal of interest in the UAV community for related spin-off applications, as briefly described at the end of the paper. In some cases the technologies under development in the free flight program are critical to the ability to perform some applications.

Pattern recognition of satellite cloud imagery for improved weather prediction

NASA Technical Reports Server (NTRS)

Gautier, Catherine; Somerville, Richard C. J.; Volfson, Leonid B.

1986-01-01

The major accomplishment was the successful development of a method for extracting time derivative information from geostationary meteorological satellite imagery. This research is a proof-of-concept study which demonstrates the feasibility of using pattern recognition techniques and a statistical cloud classification method to estimate time rate of change of large-scale meteorological fields from remote sensing data. The cloud classification methodology is based on typical shape function analysis of parameter sets characterizing the cloud fields. The three specific technical objectives, all of which were successfully achieved, are as follows: develop and test a cloud classification technique based on pattern recognition methods, suitable for the analysis of visible and infrared geostationary satellite VISSR imagery; develop and test a methodology for intercomparing successive images using the cloud classification technique, so as to obtain estimates of the time rate of change of meteorological fields; and implement this technique in a testbed system incorporating an interactive graphics terminal to determine the feasibility of extracting time derivative information suitable for comparison with numerical weather prediction products.

Applying usability testing techniques to improve a health promotion website.

PubMed

Hinchliffe, Anetta; Mummery, W Kerry

2008-04-01

Use of the Internet for health promotion is increasing; however, the lack of published research regarding website usability suggests that health promotion websites are being developed without consultation with their users or formal evaluation. This study conducted usability testing of an existing health promotion website to inform modifications and to identify common usability themes that should be addressed by organisations developing or maintaining a health promotion website. A combination of qualitative and quantitative techniques were implemented during the usability testing sessions to gather data from users while completing tasks on the website. Techniques included performance measures (time taken), direct observation (participant observation) and subjective user preferences (questionnaire and interview). Improvements to the website were measured in terms of reduced problems reported, reduced time taken to complete tasks and increased subjective reports. Seven usability themes emerged from the data: design, feedback, format, instructions, navigation, terminology and learnability. This study demonstrates the application of usability testing to the design and modification of a health promotion website and illustrates the areas or themes that can be used as a framework for testing and modification.

Design and development of pressure and repressurization purge system for reusable space shuttle multilayer insulation system

NASA Technical Reports Server (NTRS)

1972-01-01

The experimental determination of purge bag materials properties, development of purge bag manufacturing techniques, experimental evaluation of a subscale purge bag under simulated operating conditions and the experimental evaluation of the purge pin concept for MLI purging are discussed. The basic purge bag material, epoxy fiberglass bounded by skins of FEP Teflon, showed no significant permeability to helium flow under normal operating conditions. Purge bag small scale manufacturing tests were conducted to develop tooling and fabrication techniques for use in full scale bag manufacture. A purge bag material layup technique was developed whereby the two plys of epoxy fiberglass enclosed between skins of FEP Teflon are vacuum bag cured in an oven in a single operation. The material is cured on a tool with the shape of a purge bag half. Plastic tooling was selected for use in bag fabrication. A model purge bag 0.6 m in diameter was fabricated and subjected to a series of structural and environmental tests simulating various flight type environments. Pressure cycling tests at high (450 K) and low (200 K) temperature as well as acoustic loading tests were performed. The purge bag concept proved to be structurally sound and was used for the full scale bag detailed design model.

A Conceptual Model for Promoting Study Skills and Test-Taking Techniques among Secondary School Students: Curricular, Instructional/Guidance, and Assessment Perspectives.

ERIC Educational Resources Information Center

Guedry-Hymel, Linda; Hymel, Glenn M.

This paper develops a conceptual model involving curricular, instructional/guidance, and assessment perspectives on the promotion of study skills and test-taking techniques among secondary school students. From the curricular standpoint, consideration is given to a recommended range of topical coverage and a diversified array of printed/mediated…

Live fire testing requirements - Assessing the impact

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

O'Bryon, J.F.

1992-08-01

Full-up live-fire testing (LFT) of aircraft configured for combat is evaluated in terms of the practical implications of the technique. LFT legislation requires the testing of tactical fighters, helicopters, and other aircraft when they are loaded with the flammables and explosives associated with combat. LFT permits the study of damage mechanisms and battle-damage repair techniques during the design phase, and probability-of-kill estimates and novel systems designs can be developed based on LFT data.

Experimental Methods Using Photogrammetric Techniques for Parachute Canopy Shape Measurements

NASA Technical Reports Server (NTRS)

Jones, Thomas W.; Downey, James M.; Lunsford, Charles B.; Desabrais, Kenneth J.; Noetscher, Gregory

2007-01-01

NASA Langley Research Center in partnership with the U.S. Army Natick Soldier Center has collaborated on the development of a payload instrumentation package to record the physical parameters observed during parachute air drop tests. The instrumentation package records a variety of parameters including canopy shape, suspension line loads, payload 3-axis acceleration, and payload velocity. This report discusses the instrumentation design and development process, as well as the photogrammetric measurement technique used to provide shape measurements. The scaled model tests were conducted in the NASA Glenn Plum Brook Space Propulsion Facility, OH.

Development of a filter regeneration system for advanced spacecraft fluid systems

NASA Technical Reports Server (NTRS)

Behrend, A. F., Jr.; Descamp, V. A.

1974-01-01

The development of a filter regeneration system for efficiently cleaning fluid particulate filters is presented. Based on a backflush/jet impingement technique, the regeneration system demonstrated a cleaning efficiency of 98.7 to 100%. The operating principles and design features are discussed with emphasis on the primary system components that include a regenerable filter, vortex particle separator, and zero-g particle trap. Techniques and equipment used for ground and zero-g performance tests are described. Test results and conclusions, as well as possible areas for commercial application, are included.

On-board processing for telecommunications satellites

NASA Technical Reports Server (NTRS)

Nuspl, P. P.; Dong, G.

1991-01-01

In this decade, communications satellite systems will probably face dramatic challenges from alternative transmission means. To balance and overcome such competition, and to prepare for new requirements, INTELSAT has developed several on-board processing techniques, including Satellite-Switched TDMA (SS-TDMA), Satellite-Switched FDMA (SS-FDMA), several Modulators/Demodulators (Modem), a Multicarrier Multiplexer and Demodulator MCDD), an International Business Service (IBS)/Intermediate Data Rate (IDR) BaseBand Processor (BBP), etc. Some proof-of-concept hardware and software were developed, and tested recently in the INTELSAT Technical Laboratories. These techniques and some test results are discussed.

A review of modern instrumental techniques for measurements of ice cream characteristics.

PubMed

Bahram-Parvar, Maryam

2015-12-01

There is an increasing demand of the food industries and research institutes to have means of measurement allowing the characterization of foods. Ice cream, as a complex food system, consists of a frozen matrix containing air bubbles, fat globules, ice crystals, and an unfrozen serum phase. Some deficiencies in conventional methods for testing this product encourage the use of alternative techniques such as rheometry, spectroscopy, X-ray, electro-analytical techniques, ultrasound, and laser. Despite the development of novel instrumental applications in food science, use of some of them in ice cream testing is few, but has shown promising results. Developing the novel methods should increase our understanding of characteristics of ice cream and may allow online testing of the product. This review article discusses the potential of destructive and non-destructive methodologies in determining the quality and characteristics of ice cream and similar products. Copyright © 2015. Published by Elsevier Ltd.

Digital Image Correlation Techniques Applied to Large Scale Rocket Engine Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.

2016-01-01

Rocket engine hot-fire ground testing is necessary to understand component performance, reliability and engine system interactions during development. The J-2X upper stage engine completed a series of developmental hot-fire tests that derived performance of the engine and components, validated analytical models and provided the necessary data to identify where design changes, process improvements and technology development were needed. The J-2X development engines were heavily instrumented to provide the data necessary to support these activities which enabled the team to investigate any anomalies experienced during the test program. This paper describes the development of an optical digital image correlation technique to augment the data provided by traditional strain gauges which are prone to debonding at elevated temperatures and limited to localized measurements. The feasibility of this optical measurement system was demonstrated during full scale hot-fire testing of J-2X, during which a digital image correlation system, incorporating a pair of high speed cameras to measure three-dimensional, real-time displacements and strains was installed and operated under the extreme environments present on the test stand. The camera and facility setup, pre-test calibrations, data collection, hot-fire test data collection and post-test analysis and results are presented in this paper.

Test techniques for evaluating flight displays

NASA Technical Reports Server (NTRS)

Haworth, Loran A.; Newman, Richard L.

1993-01-01

The rapid development of graphics technology allows for greater flexibility in aircraft displays, but display evaluation techniques have not kept pace. Historically, display evaluation has been based on subjective opinion and not on the actual aircraft/pilot performance. Existing electronic display specifications and evaluation techniques are reviewed. A display rating technique analogous to handling qualities ratings was developed and is recommended for future evaluations. The choice of evaluation pilots is also discussed and the use of a limited number of trained evaluators is recommended over the use of a large number of operational pilots.

Applications Of Measurement Techniques To Develop Small-Diameter, Undersea Fiber Optic Cables

NASA Astrophysics Data System (ADS)

Kamikawa, Neil T.; Nakagawa, Arthur T.

1984-12-01

Attenuation, strain, and optical time domain reflectometer (OTDR) measurement techniques were applied successfully in the development of a minimum-diameter, electro-optic sea floor cable. Temperature and pressure models for excess attenuation in polymer coated, graded-index fibers were investigated analytically and experimentally using these techniques in the laboratory. The results were used to select a suitable fiber for the cable. Measurements also were performed on these cables during predeployment and sea-trial testing to verify laboratory results. Application of the measurement techniques and results are summarized in this paper.

Retention and application of Skylab experiences to future programs. [a postflight review of technical programs.

NASA Technical Reports Server (NTRS)

Gillespie, V. G.; Kelly, R. O.

1974-01-01

The problems encountered and special techniques and procedures developed on the Skylab program are described along with the experiences and practical benefits obtained for dissemination and use on future programs. Three major topics are discussed: electrical problems, mechanical problems, and special techniques. Special techniques and procedures are identified that were either developed or refined during the Skylab program. These techniques and procedures came from all manufacturing and test phases of the Skylab program and include both flight and GSE items from component level to sophisticated spaceflight systems.

A Photometric Technique for Determining Fluid Concentration using Consumer-Grade Hardware

NASA Technical Reports Server (NTRS)

Leslie, F.; Ramachandran, N.

1999-01-01

In support of a separate study to produce an exponential concentration gradient in a magnetic fluid, a noninvasive technique for determining, species concentration from off-the-shelf hardware has been developed. The approach uses a backlighted fluid test cell photographed with a commercial digital camcorder. Because the light extinction coefficient is wavelength dependent, tests were conducted to determine the best filter color to use, although some guidance was also provided using an absorption spectrophotometer. With the appropriate filter in place, the provide attenuation of the light passing, through the test cell was captured by the camcorder. The digital image was analyzed for intensity using, software from Scion Image Corp. downloaded from the Internet. The analysis provides a two-dimensional array of concentration with an average error of 0.0095 ml/ml. This technique is superior to invasive techniques, which require extraction of a sample that disturbs the concentration distribution in the test cell. Refinements of this technique using a true monochromatic laser light Source are also discussed.

PID techniques: Alternatives to RICH methods

DOE PAGES

Va’vra, J.

2017-07-05

Here, in this review article we discuss new updates on PID techniques, other than the Cherenkov method. In particular, we discuss recent efforts to develop high resolution timing, placing an emphasis on small scale test results.

Correlation study of theoretical and experimental results for spin tests of a 1/10 scale radio control model

NASA Technical Reports Server (NTRS)

Bihrle, W., Jr.

1976-01-01

A correlation study was conducted to determine the ability of current analytical spin prediction techniques to predict the flight motions of a current fighter airplane configuration during the spin entry, the developed spin, and the spin recovery motions. The airplane math model used aerodynamics measured on an exact replica of the flight test model using conventional static and forced-oscillation wind-tunnel test techniques and a recently developed rotation-balance test apparatus capable of measuring aerodynamics under steady spinning conditions. An attempt was made to predict the flight motions measured during stall/spin flight testing of an unpowered, radio-controlled model designed to be a 1/10 scale, dynamically-scaled model of a current fighter configuration. Comparison of the predicted and measured flight motions show that while the post-stall and spin entry motions were not well-predicted, the developed spinning motion (a steady flat spin) and the initial phases of the spin recovery motion are reasonably well predicted.

Characterization of fluid flow by digital correlation of scattered light

NASA Technical Reports Server (NTRS)

Gilbert, John A.; Matthys, Donald R.

1989-01-01

The objective is to produce a physical system suitable for a space environment that can measure fluid velocities in a three-dimensional volume by the development of a particle correlation velocimetry technique. Experimental studies were conducted on a field test cell to demonstrate the suitability and accuracy of digital correlation techniques for measuring two-dimensional fluid flows. This objective was satisfied by: (1) the design of an appropriate illumination and detection system for making velocity measurements within a test cell; (2) the design and construction of a test cell; (3) the preliminary evaluations on fluid and seeding requirements; and (4) the performance of controlled tests using a multiple exposure correlation technique. This presentation is represented by viewgraphs with very little text.

Flight test derived heating math models for critical locations on the orbiter during reentry

NASA Technical Reports Server (NTRS)

Hertzler, E. K.; Phillips, P. W.

1983-01-01

An analysis technique was developed for expanding the aerothermodynamic envelope of the Space Shuttle without subjecting the vehicle to sustained flight at more stressing heating conditions. A transient analysis program was developed to take advantage of the transient maneuvers that were flown as part of this analysis technique. Heat rates were derived from flight test data for various locations on the orbiter. The flight derived heat rates were used to update heating models based on predicted data. Future missions were then analyzed based on these flight adjusted models. A technique for comparing flight and predicted heating rate data and the extrapolation of the data to predict the aerothermodynamic environment of future missions is presented.

Simulation, Model Verification and Controls Development of Brayton Cycle PM Alternator: Testing and Simulation of 2 KW PM Generator with Diode Bridge Output

NASA Technical Reports Server (NTRS)

Stankovic, Ana V.

2003-01-01

Professor Stankovic will be developing and refining Simulink based models of the PM alternator and comparing the simulation results with experimental measurements taken from the unit. Her first task is to validate the models using the experimental data. Her next task is to develop alternative control techniques for the application of the Brayton Cycle PM Alternator in a nuclear electric propulsion vehicle. The control techniques will be first simulated using the validated models then tried experimentally with hardware available at NASA. Testing and simulation of a 2KW PM synchronous generator with diode bridge output is described. The parameters of a synchronous PM generator have been measured and used in simulation. Test procedures have been developed to verify the PM generator model with diode bridge output. Experimental and simulation results are in excellent agreement.

Applying EVM to Satellite on Ground and In-Orbit Testing - Better Data in Less Time

NASA Technical Reports Server (NTRS)

Peters, Robert; Lebbink, Elizabeth-Klein; Lee, Victor; Model, Josh; Wezalis, Robert; Taylor, John

2008-01-01

Using Error Vector Magnitude (EVM) in satellite integration and test allows rapid verification of the Bit Error Rate (BER) performance of a satellite link and is particularly well suited to measurement of low bit rate satellite links where it can result in a major reduction in test time (about 3 weeks per satellite for the Geosynchronous Operational Environmental Satellite [GOES] satellites during ground test) and can provide diagnostic information. Empirical techniques developed to predict BER performance from EVM measurements and lessons learned about applying these techniques during GOES N, O, and P integration test and post launch testing, are discussed.

Analyses of requirements for computer control and data processing experiment subsystems. Volume 1: ATM experiment S-056 image data processing system techniques development

NASA Technical Reports Server (NTRS)

1972-01-01

The solar imaging X-ray telescope experiment (designated the S-056 experiment) is described. It will photograph the sun in the far ultraviolet or soft X-ray region. Because of the imaging characteristics of this telescope and the necessity of using special techniques for capturing images on film at these wave lengths, methods were developed for computer processing of the photographs. The problems of image restoration were addressed to develop and test digital computer techniques for applying a deconvolution process to restore overall S-056 image quality. Additional techniques for reducing or eliminating the effects of noise and nonlinearity in S-056 photographs were developed.

A historical overview of flight flutter testing

NASA Technical Reports Server (NTRS)

Kehoe, Michael W.

1995-01-01

This paper reviews the test techniques developed over the last several decades for flight flutter testing of aircraft. Structural excitation systems, instrumentation systems, digital data preprocessing, and parameter identification algorithms (for frequency and damping estimates from the response data) are described. Practical experiences and example test programs illustrate the combined, integrated effectiveness of the various approaches used. Finally, comments regarding the direction of future developments and needs are presented.

Effect of Web Assisted Education Supported by Six Thinking Hats on Students' Academic Achievement in Science and Technology Classes

ERIC Educational Resources Information Center

Ercan, Orhan; Bilen, Kadir

2014-01-01

Advances in computer technologies and adoption of related methods and techniques in education have developed parallel to each other. This study focuses on the need to utilize more than one teaching method and technique in education rather than focusing on a single teaching method. By using the pre-test post-test and control group semi-experimental…

Perspectives of SiC-Based Ceramic Composites and Their Applications to Fusion Reactors 5.Development of Evaluation and Application Techniques of SiC⁄SiC Composites for Fusion Reactors

NASA Astrophysics Data System (ADS)

Hinoki, Tatsuya

Evaluation techniques and mechanical properties of silicon carbide composites (SiC⁄SiC composites) reinforced with highly crystalline fibers are reviewed for fusion applications. The SiC⁄SiC composites used were fabricated by means of the CVI method. The evaluation includes in-plane tensile strength by in-plane tensile test, transthickness tensile strength by transthickness tensile test and diametral compression test and shear strength by compression test using double-notched specimen. All tests were successfully conducted using small specimens for neutron irradiation experiment. As application technique, the novel tungsten(W) coating technique on SiC is reviewed. The W powder melted by high power lamp in a few seconds and formed coating on SiC. No thick reaction layers of WC and W5Si3, which are formed by the other coating methods, were formed by this method.

Remote Leak Detection: Indirect Thermal Technique

NASA Technical Reports Server (NTRS)

Clements, Sandra

2002-01-01

Remote sensing technologies are being considered for efficient, low cost gas leak detection. Eleven specific techniques have been identified for further study and evaluation of several of these is underway. The Indirect Thermal Technique is one of the techniques that is being explored. For this technique, an infrared camera is used to detect the temperature change of a pipe or fitting at the site of a gas leak. This temperature change is caused by the change in temperature of the gas expanding from the leak site. During the 10-week NFFP program, the theory behind the technique was further developed, experiments were performed to determine the conditions for which the technique might be viable, and a proof-of-concept system was developed and tested in the laboratory.

Development of an Electron-capture Technique Specific for Explosives Detection

DOT National Transportation Integrated Search

1974-07-01

This document contains information on the design, fabrication, and testing of a prototype detector specific for explosives which employs electron-capture sensors. The technique used exploits the observation that the electronegative vapors from explos...

Seismic field measurements in Kylylahti, Finland, in support of the further development of geophysical seismic techniques for CTBT On-site Inspections

NASA Astrophysics Data System (ADS)

Labak, Peter; Lindblom, Pasi; Malich, Gregor

2017-04-01

The Integrated Field Exercise of 2014 (IFE14) was a field event held in the Hashemite Kingdom of Jordan (with concurrent activities in Austria) during which the operational and technical capabilities of a Comprehensive Test Ban Treaty's (CTBT) on-site inspection (OSI) were tested in integrated manner. Many of the inspection techniques permitted by the CTBT were applied during IFE14 including a range of geophysical techniques, however, one of the techniques foreseen by the CTBT but not yet developed is resonance seismometry. During August and September 2016, seismic field measurements have been conducted in the region of Kylylahti, Finland, in support of the further development of geophysical seismic techniques for OSIs. 45 seismic stations were used to continuously acquire seismic signals. During that period, data from local, regional and teleseismic natural events and man-made events were acquired, including from a devastating earthquake in Italy and the nuclear explosion announced by the Democratic People's Republic of Korea on 9 September 2016. Also, data were acquired following the small-scale use of man-made chemical explosives in the area and of vibratory sources. This presentation will show examples from the data set and will discuss its use for the development of resonance seimometry for OSIs.

Data Mining Techniques for Identifying Students at Risk of Failing a Computer Proficiency Test Required for Graduation

ERIC Educational Resources Information Center

Tsai, Chih-Fong; Tsai, Ching-Tzu; Hung, Chia-Sheng; Hwang, Po-Sen

2011-01-01

Enabling undergraduate students to develop basic computing skills is an important issue in higher education. As a result, some universities have developed computer proficiency tests, which aim to assess students' computer literacy. Generally, students are required to pass such tests in order to prove that they have a certain level of computer…

Development and Experimental Application of International Affairs Indicators. Volume A

DTIC Science & Technology

1974-06-01

DEVELOPMENT ’^EXPERIMENTAL APPttcATION OF INTERNATIONAL AFFAIRS INDICATORS Volume A Final Report e June 1974 US I Sponsored by: Defense Advanced...intelligence communities were designed, techniques for estimating the future were developed and tested, and the techniques and indicators were applied to the...past year’s effort is that the intelligence community has become increasingly aware of the potential use- fulness of quantitative indicators. The

Nuclear techniques in studies of condensed matter

NASA Technical Reports Server (NTRS)

Singh, Jag J.

1987-01-01

Nuclear techniques have played an important role in the studies of materials over the past several decades. For example, X-ray diffraction, neutron diffraction, neutron activation, and particle- or photon-induced X-ray emission techniques have been used extensively for the elucidation of structural and compositional details of materials. Several new techniques have been developed recently. Four such techniques are briefly reviewed which have great potential in the study and development of new materials. Of these four, Mossbauer spectroscopy, muon spin rotation, and positron annihilation spectroscopy techniques exploit their great sensitivity to the local atomic environments in the test materials. Interest in synchrotron radiation, on the other hand, stems from its special properties, such as high intensity, high degree of polarization, and high monochromaticity. It is hoped that this brief review will stimulate interest in the exploitation of these newer techniques for the development of improved materials.

A study for hypergolic vapor sensor development

NASA Technical Reports Server (NTRS)

Stetter, J. R.; Tellefsen, K.

1977-01-01

In summary, the following tasks were completed within the scope of this work: (1) a portable Monomethylhydrazine analyzer was developed, designed, fabricated and tested. (2) A portable NO2 analyzer was developed, designed, fabricated and tested. (3) Sampling probes and accessories were designed and fabricated for this instrumentation. (4) Improvements and modifications were made to the model 7630 Ecolyzer in preparation for field testing. (5) Instrument calibration procedures and hydrazine handling techniques necessary to the successful application of this hardware were developed.

Development of airframe design technology for crashworthiness.

NASA Technical Reports Server (NTRS)

Kruszewski, E. T.; Thomson, R. G.

1973-01-01

This paper describes the NASA portion of a joint FAA-NASA General Aviation Crashworthiness Program leading to the development of improved crashworthiness design technology. The objectives of the program are to develop analytical technology for predicting crashworthiness of structures, provide design improvements, and perform full-scale crash tests. The analytical techniques which are being developed both in-house and under contract are described, and typical results from these analytical programs are shown. In addition, the full-scale testing facility and test program are discussed.

Engine component instrumentation development facility at NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.; Buggele, Alvin E.; Lepicovsky, Jan

1992-01-01

The Engine Components Instrumentation Development Facility at NASA Lewis is a unique aeronautics facility dedicated to the development of innovative instrumentation for turbine engine component testing. Containing two separate wind tunnels, the facility is capable of simulating many flow conditions found in most turbine engine components. This facility's broad range of capabilities as well as its versatility provide an excellent location for the development of novel testing techniques. These capabilities thus allow a more efficient use of larger and more complex engine component test facilities.

Development of Supersonic Combustion Experiments for CFD Modeling

NASA Technical Reports Server (NTRS)

Baurle, Robert; Bivolaru, Daniel; Tedder, Sarah; Danehy, Paul M.; Cutler, Andrew D.; Magnotti, Gaetano

2007-01-01

This paper describes the development of an experiment to acquire data for developing and validating computational fluid dynamics (CFD) models for turbulence in supersonic combusting flows. The intent is that the flow field would be simple yet relevant to flows within hypersonic air-breathing engine combustors undergoing testing in vitiated-air ground-testing facilities. Specifically, it describes development of laboratory-scale hardware to produce a supersonic combusting coaxial jet, discusses design calculations, operability and types of flames observed. These flames are studied using the dual-pump coherent anti- Stokes Raman spectroscopy (CARS) - interferometric Rayleigh scattering (IRS) technique. This technique simultaneously and instantaneously measures temperature, composition, and velocity in the flow, from which many of the important turbulence statistics can be found. Some preliminary CARS data are presented.

Application of additive laser technologies in the gas turbine blades design process

NASA Astrophysics Data System (ADS)

Shevchenko, I. V.; Rogalev, A. N.; Osipov, S. K.; Bychkov, N. M.; Komarov, I. I.

2017-11-01

An emergence of modern innovative technologies requires delivering new and modernization existing design and production processes. It is especially relevant for designing the high-temperature turbines of gas turbine engines, development of which is characterized by a transition to higher parameters of working medium in order to improve their efficient performance. A design technique for gas turbine blades based on predictive verification of thermal and hydraulic models of their cooling systems by testing of a blade prototype fabricated using the selective laser melting technology was presented in this article. Technique was proven at the time of development of the first stage blade cooling system for the high-pressure turbine. An experimental procedure for verification of a thermal model of the blades with convective cooling systems based on the comparison of heat-flux density obtained from the numerical simulation data and results of tests in a liquid-metal thermostat was developed. The techniques makes it possible to obtain an experimentally tested blade version and to exclude its experimental adjustment after the start of mass production.

Development of a shock wave adhesion test for composite bonds by pulsed laser and mechanical impacts

NASA Astrophysics Data System (ADS)

Ecault, R.; Boustie, M.; Touchard, F.; Arrigoni, M.; Berthe, L.

2014-05-01

Evaluating the bonding quality of composite material is becoming one of the main challenges faced by aeronautic industries. This work aims to the development of a technique using shock wave, which would enable to quantify the bonding mechanical quality. Laser shock experiments were carried out. This technique enables high tensile stress generation in the thickness of composite bonds. The resulting damage has been quantified using different methods such as confocal microscopy, ultrasound and cross section observation. The discrimination between a correct bond and a weak bond was possible thanks to these experiments. Nevertheless, laser sources are not well adapted for optimization of such a test because of often fixed settings. That is why mechanical impacts on bonded composites were also performed in this work. By changing the thickness of aluminum projectiles, the generated tensile stresses by the shock wave propagation were moved toward the composite/bond interface. The made observations prove that the technique optimization is possible. The key parameters for the development of a bonding test using shock waves have been identified.

Development of a shock wave adhesion test for composite bonds by laser pulsed and mechanical impacts

NASA Astrophysics Data System (ADS)

Ecault, Romain; Boustie, Michel; Touchard, Fabienne; Arrigoni, Michel; Berthe, Laurent; CNRS Collaboration

2013-06-01

Evaluating the bonding quality of composite material is becoming one of the main challenges faced by aeronautic industries. This work aims the development of a technique using shock wave, which would enable to quantify the bonding mechanical quality. Laser shock experiments were carried out. This technique enables high tensile stress generation in the thickness of composite bond without any mechanical contact. The resulting damage has been quantified using different method such as confocal microscopy, ultrasound and cross section observation. The discrimination between a correct bond and a weak bond was possible thanks to these experiments. Nevertheless, laser sources are not well adapted for optimization of such a test since it has often fixed parameters. That is why mechanical impacts bonded composites were also performed in this work. By changing the thickness of aluminum projectiles, the tensile stresses generated by the shock wave propagation were moved toward the composite/bond interface. The observations made prove that the optimization of the technique is possible. The key parameters for the development of a bonding test using shock wave have been identified.

The measurement of the heat-transfer coefficient between high-temperature liquids and solid surfaces

NASA Astrophysics Data System (ADS)

Utigard, T. A.; Warczok, A.; Desclaux, P.

1994-01-01

Two experimental techniques were developed for the purpose of measuring the heat-transfer coefficient between liquid slags/salts and solid surfaces. This was carried out because the heat-transfer coefficient is important for the design and operation of metallurgical reactors. A “cold-finger” technique was developed for the purpose of carrying out heat-transfer measurements during steady-state conditions simulating heat fluxes through furnace sidewalls. A lump capacitance method was developed and tested for the purpose of simulating transient conditions. To determine the effect of fluid flow on the heat-transfer coefficient, nitrogen gas stirring was used. The two techniques were tested in molten (1) and NaNO3, (2) NaCl, (3) Na3AlF6, and (4) 2FeO·SiO2, giving consistent results. It was found that the heat-transfer coefficient increases with increasing bath superheat and stirring.

Failure detection and isolation analysis of a redundant strapdown inertial measurement unit

NASA Technical Reports Server (NTRS)

Motyka, P.; Landey, M.; Mckern, R.

1981-01-01

The objective of this study was to define and develop techniques for failure detection and isolation (FDI) algorithms for a dual fail/operational redundant strapdown inertial navigation system are defined and developed. The FDI techniques chosen include provisions for hard and soft failure detection in the context of flight control and navigation. Analyses were done to determine error detection and switching levels for the inertial navigation system, which is intended for a conventional takeoff or landing (CTOL) operating environment. In addition, investigations of false alarms and missed alarms were included for the FDI techniques developed, along with the analyses of filters to be used in conjunction with FDI processing. Two specific FDI algorithms were compared: the generalized likelihood test and the edge vector test. A deterministic digital computer simulation was used to compare and evaluate the algorithms and FDI systems.

New test techniques and analytical procedures for understanding the behavior of advanced propellers

NASA Technical Reports Server (NTRS)

Stefko, G. L.; Bober, L. J.; Neumann, H. E.

1983-01-01

Analytical procedures and experimental techniques were developed to improve the capability to design advanced high speed propellers. Some results from the propeller lifting line and lifting surface aerodynamic analysis codes are compared with propeller force data, probe data and laser velocimeter data. In general, the code comparisons with data indicate good qualitative agreement. A rotating propeller force balance demonstrated good accuracy and reduced test time by 50 percent. Results from three propeller flow visualization techniques are shown which illustrate some of the physical phenomena occurring on these propellers.

Higher-Order Spectral Analysis of F-18 Flight Flutter Data

NASA Technical Reports Server (NTRS)

Silva, Walter A.; Dunn, Shane

2005-01-01

Royal Australian Air Force (RAAF) F/A-18 flight flutter test data is presented and analyzed using various techniques. The data includes high-quality measurements of forced responses and limit cycle oscillation (LCO) phenomena. Standard correlation and power spectral density (PSD) techniques are applied to the data and presented. Novel applications of experimentally-identified impulse responses and higher-order spectral techniques are also applied to the data and presented. The goal of this research is to develop methods that can identify the onset of nonlinear aeroelastic phenomena, such as LCO, during flutter testing.

Fault detection techniques for complex cable shield topologies

NASA Astrophysics Data System (ADS)

Coonrod, Kurt H.; Davis, Stuart L.; McLemore, Donald P.

1994-09-01

This document presents the results of a basic principles study which investigated technical approaches for developing fault detection techniques for use on cables with complex shielding topologies. The study was limited to those approaches which could realistically be implemented on a fielded cable, i.e., approaches which would require partial disassembly of a cable were not pursued. The general approach used was to start with present transfer impedance measurement techniques and modify their use to achieve the best possible measurement range. An alternative test approach, similar to a sniffer type test, was also investigated.

Advanced wiring technique and hardware application: Airplane and space vehicle

NASA Technical Reports Server (NTRS)

Ernst, H. L.; Eichman, C. D.

1972-01-01

An advanced wiring system is described which achieves the safety/reliability required for present and future airplane and space vehicle applications. Also, present wiring installation techniques and hardware are analyzed to establish existing problem areas. An advanced wiring system employing matrix interconnecting unit, plug to plug trunk bundles (FCC or ribbon cable) is outlined, and an installation study presented. A planned program to develop, lab test and flight test key features of these techniques and hardware as a part of the SST technology follow-on activities is discussed.

Subcritical flutter testing and system identification

NASA Technical Reports Server (NTRS)

Houbolt, J. C.

1974-01-01

Treatment is given of system response evaluation, especially in application to subcritical flight and wind tunnel flutter testing of aircraft. An evaluation is made of various existing techniques, in conjuction with a companion survey which reports theoretical and analog experiments made to study the identification of system response characteristics. Various input excitations are considered, and new techniques for analyzing response are explored, particularly in reference to the prevalent practical case where unwanted input noise is present, such as caused by gusts or wind tunnel turbulence. Further developments are also made of system parameter identification techniques.

Linear Array Ultrasonic Test Results from Alkali-Silica Reaction (ASR) Specimens

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

Clayton, Dwight A; Khazanovich, Dr. Lev; Salles, Lucio

2016-04-01

The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the variousmore » nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations.This report presents results of the ultrasound evaluation of four concrete slabs with varying levels of ASR damage present. This included an investigation of the experimental results, as well as a supplemental simulation considering the effect of ASR damage by elasto-dynamic wave propagation using a finite integration technique method. It was found that the Hilbert Transform Indicator (HTI), developed for quantification of freeze/thaw damage in concrete structures, could also be successfully utilized for quantification of ASR damage. internal microstructure flaws, and reinforcement locations.« less

A Technique for Transient Thermal Testing of Thick Structures

NASA Technical Reports Server (NTRS)

Horn, Thomas J.; Richards, W. Lance; Gong, Leslie

1997-01-01

A new open-loop heat flux control technique has been developed to conduct transient thermal testing of thick, thermally-conductive aerospace structures. This technique uses calibration of the radiant heater system power level as a function of heat flux, predicted aerodynamic heat flux, and the properties of an instrumented test article. An iterative process was used to generate open-loop heater power profiles prior to each transient thermal test. Differences between the measured and predicted surface temperatures were used to refine the heater power level command profiles through the iteration process. This iteration process has reduced the effects of environmental and test system design factors, which are normally compensated for by closed-loop temperature control, to acceptable levels. The final revised heater power profiles resulted in measured temperature time histories which deviated less than 25 F from the predicted surface temperatures.

Biosensors for Mycotoxin Analysis: Recent Developments and Future Prospects

USDA-ARS?s Scientific Manuscript database

The toxicity and prevalence of mycotoxins in commodities and foods has necessitated the development of rapid methods in order to ensure the protection of human food and animal feed supplies. Testing for mycotoxins can be accomplished by many techniques that range from determinative tests in which t...

Testing the Untestable: A Vision Screening Program for Exceptional Children.

ERIC Educational Resources Information Center

Bishop, Virginia E.; Godolphin, Vivienne

Based on a longitudinal study of vision screening techniques for handicapped children at the Chester County (Pennsylvania) Child Development Center, the paper reports on the development of a battery of effective vision screening methods for children with low functioning handicapped children. Specific tests are described, including the Sheridan…

Ultrasonic technique for inspection of GPHS capsule girth weld integrity

NASA Astrophysics Data System (ADS)

Placr, Arnost

1993-05-01

An innovative nondestructive examination (NDE) technique for the inspection of integrity of General Purpose Heat Source (GPHS) capsule girth welds was developed employing a Lamb wave as the mode of the sound propagation. Reliability of the Lamb wave technique was tested on GPHS capsules using plutonium pallet simulators. All ten capsules, which were previously rejected, passed ultrasonic (UT) inspection using the Lamb wave technique.

SRB Environment Evaluation and Analysis. Volume 2: RSRB Joint Filling Test/Analysis Improvements

NASA Technical Reports Server (NTRS)

Knox, E. C.; Woods, G. Hamilton

1991-01-01

Following the Challenger accident a very comprehensive solid rocket booster (SRB) redesign program was initiated. One objective of the program was to develop expertise at NASA/MSFC in the techniques for analyzing the flow of hot gases in the SRB joints. Several test programs were undertaken to provide a data base of joint performance with manufactured defects in the joints to allow hot gases to fill the joints. This data base was used also to develop the analytical techniques. Some of the test programs were Joint Environment Simulator (JES), Nozzle Joint Environment Simulator (NJES), Transient Pressure Test Article (TPTA), and Seventy-Pound Charge (SPC). In 1988 the TPTA test hardware was moved from the Utah site to MSFC and several RSRM tests were scheduled, to be followed by tests for the ASRM program. REMTECH Inc. supported these activities with pretest estimates of the flow conditions in the test joints, and post-test analysis and evaluation of the measurements. During this support REMTECH identified deficiencies in the gas-measurement instrumentation that existed in the TPTA hardware, made recommendations for its replacement, and identified improvements to the analytical tools used in the test support. Only one test was completed under the TPTA RSRM test program, and those scheduled for the ASRM were rescheduled to a time after the expiration of this contract. The attention of this effort was directed toward improvements in the analytical techniques in preparation for when the ASRM program begins.

Are Independent Probes Truly Independent?

ERIC Educational Resources Information Center

Camp, Gino; Pecher, Diane; Schmidt, Henk G.; Zeelenberg, Rene

2009-01-01

The independent cue technique has been developed to test traditional interference theories against inhibition theories of forgetting. In the present study, the authors tested the critical criterion for the independence of independent cues: Studied cues not presented during test (and unrelated to test cues) should not contribute to the retrieval…

Development and Hotfire Testing of Additively Manufactured Copper Combustion Chambers for Liquid Rocket Engine Applications

NASA Technical Reports Server (NTRS)

Gradl, Paul R.; Greene, Sandy; Protz, Chris

2017-01-01

NASA and industry partners are working towards fabrication process development to reduce costs and schedules associated with manufacturing liquid rocket engine components with the goal of reducing overall mission costs. One such technique being evaluated is powder-bed fusion or selective laser melting (SLM), commonly referred to as additive manufacturing (AM). The NASA Low Cost Upper Stage Propulsion (LCUSP) program was designed to develop processes and material characterization for GRCop-84 (a NASA Glenn Research Center-developed copper, chrome, niobium alloy) commensurate with powder bed AM, evaluate bimetallic deposition, and complete testing of a full scale combustion chamber. As part of this development, the process has been transferred to industry partners to enable a long-term supply chain of monolithic copper combustion chambers. To advance the processes further and allow for optimization with multiple materials, NASA is also investigating the feasibility of bimetallic AM chambers. In addition to the LCUSP program, NASA’s Marshall Space Flight Center (MSFC) has completed a series of development programs and hot-fire tests to demonstrate SLM GRCop-84 and other AM techniques. MSFC’s efforts include a 4,000 pounds-force thrust liquid oxygen/methane (LOX/CH4) combustion chamber. Small thrust chambers for 1,200 pounds-force LOX/hydrogen (H2) applications have also been designed and fabricated with SLM GRCop-84. Similar chambers have also completed development with an Inconel 625 jacket bonded to the GRCop-84 material, evaluating direct metal deposition (DMD) laser- and arc-based techniques. The same technologies for these lower thrust applications are being applied to 25,000-35,000 pounds-force main combustion chamber (MCC) designs. This paper describes the design, development, manufacturing and testing of these numerous combustion chambers, and the associated lessons learned throughout their design and development processes.

Studies and testing of antireflective (AR) coatings for soda-lime glass

NASA Technical Reports Server (NTRS)

Pastirik, E. M.; Sparks, T. G.; Coleman, M. G.

1978-01-01

Processes for producing antireflection films on glass are concentrated in three areas: acid etching of glass, plasma etching of glass, and acid development of sodium silicate films on glass. The best transmission was achieved through the acid etching technique, while the most durable films were produced from development of sodium silicate films. Control of the acid etching technique is presently inadequate for production implementation. While films having excellent antireflective properties were fabricated by plasma etching techniques, all were water soluble.

Digital education and dynamic assessment of tongue diagnosis based on Mashup technique.

PubMed

Tsai, Chin-Chuan; Lo, Yen-Cheng; Chiang, John Y; Sainbuyan, Natsagdorj

2017-01-24

To assess the digital education and dynamic assessment of tongue diagnosis based on Mashup technique (DEDATD) according to specifific user's answering pattern, and provide pertinent information tailored to user's specifific needs supplemented by the teaching materials constantly updated through the Mashup technique. Fifty-four undergraduate students were tested with DEDATD developed. The effificacy of the DEDATD was evaluated based on the pre- and post-test performance, with interleaving training sessions targeting on the weakness of the student under test. The t-test demonstrated that signifificant difference was reached in scores gained during pre- and post-test sessions, and positive correlation between scores gained and length of time spent on learning, while no signifificant differences between the gender and post-test score, and the years of students in school and the progress in score gained. DEDATD, coupled with Mashup technique, could provide updated materials fifiltered through diverse sources located across the network. The dynamic assessment could tailor each individual learner's needs to offer custom-made learning materials. DEDATD poses as a great improvement over the traditional teaching methods.

Multipath/RFI/modulation study for DRSS-RFI problem: Voice coding and intelligibility testing for a satellite-based air traffic control system

NASA Technical Reports Server (NTRS)

Birch, J. N.; Getzin, N.

1971-01-01

Analog and digital voice coding techniques for application to an L-band satellite-basedair traffic control (ATC) system for over ocean deployment are examined. In addition to performance, the techniques are compared on the basis of cost, size, weight, power consumption, availability, reliability, and multiplexing features. Candidate systems are chosen on the bases of minimum required RF bandwidth and received carrier-to-noise density ratios. A detailed survey of automated and nonautomated intelligibility testing methods and devices is presented and comparisons given. Subjective evaluation of speech system by preference tests is considered. Conclusion and recommendations are developed regarding the selection of the voice system. Likewise, conclusions and recommendations are developed for the appropriate use of intelligibility tests, speech quality measurements, and preference tests with the framework of the proposed ATC system.

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

Yoder Jr, Graydon L; Heatherly, Dennis Wayne; Williams, David F

A small molten fluoride salt experiment has been constructed and tested to develop experimental techniques for application in liquid fluoride salt systems. There were five major objectives in developing this test apparatus: Allow visual observation of the salt during testing (how can lighting be introduced, how can pictures be taken, what can be seen) Determine if IR photography can be used to examine components submerged in the salt Determine if the experimental configuration provides salt velocity sufficient for collection of corrosion data for future experimentation Determine if a laser Doppler velocimeter can be used to quantify salt velocities. Acquire naturalmore » circulation heat transfer data in fluoride salt at temperatures up to 700oC All of these objectives were successfully achieved during testing with the exception of the fourth: acquiring velocity data using the laser Doppler velocimeter. This paper describes the experiment and experimental techniques used, and presents data taken during natural circulation testing.« less

Finite-element analysis and modal testing of a rotating wind turbine

NASA Astrophysics Data System (ADS)

Carne, T. G.; Lobitz, D. W.; Nord, A. R.; Watson, R. A.

1982-10-01

A finite element procedure, which includes geometric stiffening, and centrifugal and Coriolis terms resulting from the use of a rotating coordinate system, was developed to compute the mode shapes and frequencies of rotating structures. Special applications of this capability was made to Darrieus, vertical axis wind turbines. In a parallel development effort, a technique for the modal testing of a rotating vertical axis wind turbine is established to measure modal parameters directly. Results from the predictive and experimental techniques for the modal frequencies and mode shapes are compared over a wide range of rotational speeds.

Finite element analysis and modal testing of a rotating wind turbine

NASA Astrophysics Data System (ADS)

Carne, T. G.; Lobitz, D. W.; Nord, A. R.; Watson, R. A.

A finite element procedure, which includes geometric stiffening, and centrifugal and Coriolis terms resulting from the use of a rotating coordinate system, has been developed to compute the mode shapes and frequencies of rotating structures. Special application of this capability has been made to Darrieus, vertical axis wind turbines. In a parallel development effort, a technique for the modal testing of a rotating vertical axis wind turbine has been established to measure modal parameters directly. Results from the predictive and experimental techniques for the modal frequencies and mode shapes are compared over a wide range of rotational speeds.

A unique control system simulator for the evaluation of pulsed plasma thrusters

NASA Technical Reports Server (NTRS)

Dahlgren, J. B.

1973-01-01

Because of the low thrust characteristics of solid-propellant pulsed plasma thrusters and their operational requirement to operate in a vacuum environment, unique and sensitive test techniques are required. A technique evolved for testing and evaluating pulsed plasma thrusters in an open- or closed-loop system mode employs a unique air bearing platform as a single-axis simulator on which the thruster is mounted. The simulator described was developed to evaluate pulsed plasma thrusters in the low micropound range; however, the simulator can be extended to cover the operational range of currently developed millipound thrusters.

Innovative signal processing for Johnson Noise thermometry

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

Ezell, N. Dianne Bull; Britton, Jr, Charles L.; Roberts, Michael

This report summarizes the newly developed algorithm that subtracted the Electromagnetic Interference (EMI). The EMI performance is very important to this measurement because any interference in the form on pickup from external signal sources from such as fluorescent lighting ballasts, motors, etc. can skew the measurement. Two methods of removing EMI were developed and tested at various locations. This report also summarizes the testing performed at different facilities outside Oak Ridge National Laboratory using both EMI removal techniques. The first EMI removal technique reviewed in previous milestone reports and therefore this report will detail the second method.

Comparability of a Paper-Based Language Test and a Computer-Based Language Test.

ERIC Educational Resources Information Center

Choi, Inn-Chull; Kim, Kyoung Sung; Boo, Jaeyool

2003-01-01

Utilizing the Test of English Proficiency, developed by Seoul National University (TEPS), examined comparability between the paper-based language test and the computer-based language test based on content and construct validation employing content analyses based on corpus linguistic techniques in addition to such statistical analyses as…

Student Assessment System. Domain Referenced Tests. Cosmetology. Volume I: Skills. Georgia Vocational Education Program Articulation.

ERIC Educational Resources Information Center

Rice, Linda Maxwell; And Others

These performance tests for the area of cosmetology consist of a sampling technique (domain referenced tests) which covers all the possible performance situations. When used in total, they may also serve as a comprehensive test. Introductory materials discuss domain referenced testing, determining the domains, and developing performance testing…

A microinjection technique for targeting regions of embryonic and neonatal mouse brain in vivo

PubMed Central

Davidson, Steve; Truong, Hai; Nakagawa, Yasushi; Giesler, Glenn J

2009-01-01

A simple pressure injection technique was developed to deliver substances into specific regions of the embryonic and neonatal mouse brain in vivo. The retrograde tracers Fluorogold and cholera toxin B subunit were used to test the validity of the technique. Injected animals survived the duration of transport (24–48 hrs) and then were sacrificed and perfused with fixative. Small injections (≤ 50 nL) were contained within targeted structures of the perinatal brain and labeled distant cells of origin in several model neural pathways. Traced neural pathways in the perinatal mouse were further examined with immunohistochemical methods to test the feasibility of double labeling experiments during development. Several experimental situations in which this technique would be useful are discussed, for example, to label projection neurons in slice or culture preparations of mouse embryos and neonates. The administration of pharmacological or genetic vectors directly into specific neural targets during development should also be feasible. An examination of the form of neural pathways during early stages of life may lead to insights regarding the functional changes that occur during critical periods of development and provide an anatomic basis for some neurodevelopmental disorders. PMID:19840780

Development of an Intelligent Videogrammetric Wind Tunnel Measurement System

NASA Technical Reports Server (NTRS)

Graves, Sharon S.; Burner, Alpheus W.

2004-01-01

A videogrammetric technique developed at NASA Langley Research Center has been used at five NASA facilities at the Langley and Ames Research Centers for deformation measurements on a number of sting mounted and semispan models. These include high-speed research and transport models tested over a wide range of aerodynamic conditions including subsonic, transonic, and supersonic regimes. The technique, based on digital photogrammetry, has been used to measure model attitude, deformation, and sting bending. In addition, the technique has been used to study model injection rate effects and to calibrate and validate methods for predicting static aeroelastic deformations of wind tunnel models. An effort is currently underway to develop an intelligent videogrammetric measurement system that will be both useful and usable in large production wind tunnels while providing accurate data in a robust and timely manner. Designed to encode a higher degree of knowledge through computer vision, the system features advanced pattern recognition techniques to improve automated location and identification of targets placed on the wind tunnel model to be used for aerodynamic measurements such as attitude and deformation. This paper will describe the development and strategy of the new intelligent system that was used in a recent test at a large transonic wind tunnel.

Probabilistic thermal-shock strength testing using infrared imaging

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

Wereszczak, A.A.; Scheidt, R.A.; Ferber, M.K.

1999-12-01

A thermal-shock strength-testing technique has been developed that uses a high-resolution, high-temperature infrared camera to capture a specimen's surface temperature distribution at fracture. Aluminum nitride (AlN) substrates are thermally shocked to fracture to demonstrate the technique. The surface temperature distribution for each test and AlN's thermal expansion are used as input in a finite-element model to determine the thermal-shock strength for each specimen. An uncensored thermal-shock strength Weibull distribution is then determined. The test and analysis algorithm show promise as a means to characterize thermal shock strength of ceramic materials.

Development of a sensitive and specific indirect enzyme-linked immunosorbent assay based on a baculovirus recombinant antigen for detection of specific antibodies against Ehrlichia canis.

PubMed

López, Lissett; Venteo, Angel; Aguirre, Enara; García, Marga; Rodríguez, Majosé; Amusátegui, Inmaculada; Tesouro, Miguel A; Vela, Carmen; Sainz, Angel; Rueda, Paloma

2007-11-01

An indirect enzyme-linked immunosorbent assay (ELISA) based on baculovirus recombinant P30 protein of Ehrlichia canis and the 1BH4 anticanine IgG monoclonal antibody was developed and evaluated by examining a panel of 98 positive and 157 negative sera using the indirect fluorescent antibody (IFA) test as the reference technique. The P30-based ELISA appeared to be sensitive and specific (77.55% and 95.54%, respectively) when qualitative results (positive/negative) were compared with those of the IFA test; the coefficient of correlation (R) between the 2 tests was 0.833. Furthermore, it was possible to establish a mathematical formula for use in comparing the results of both techniques. These results indicate that recombinant P30 antigen-based ELISA is a suitable alternative of the IFA test for simple, consistent, and rapid serodiagnosis of canine ehrlichiosis. Moreover, the use of this recombinant protein as antigen offers a great advantage for antigen preparation in comparison with other techniques in which the whole E. canis organism is used as antigen.

Electronic test instrumentation and techniques: A compilation

NASA Technical Reports Server (NTRS)

1974-01-01

The uses of test equipment and techniques used in space research and development programs are discussed. Modifications and adaptations to enlarge the scope of usefulness or divert the basic uses to alternate applications are analyzed. The items of equipment which have been of benefit to professional personnel in the enlargement and improvement of quality control capabilities are identified. Items which have been simplified or made more accurate in conducting measurements are described.

Office of the Secretary of Defense Research, Development Test and Evaluation, Development and Test Evaluation, Defense, Director of Operational Test and Evaluation Defense, FY 1994 Budget Estimates, Justification of Estimates Submitted to Congress April 1993

DTIC Science & Technology

1993-04-01

separation capability. o Demonstrate advanced KKVs in the 6-20 KG weight class. o Test planning for SRAM/LEAP and PATRIOT/LEAP integrated technology...packaging techniques to reduce satellite size, weight , power, and total system costs. Further development of these technologies are absolutely 4...1993 o Developed a master plan with a delivery schedule for each light- weight subassembly in the sensor integration payload. o Finalized a contract for

Bibliography of In-House and Contract Reports, Supplement 18

DTIC Science & Technology

1992-10-01

Transparent Conforming Overlays 46 TITLE REPORT NO. YEAR Development, Service Tests, and Production Model 1307 -TR 1953 Tests, Autofocusing Rectifier...Development, Test, Preparation, Delivery, and ETL- 1307 1982 Installation of Algorithms for Optimal Adjustment of Inertial Survey Data Developmental Optical...B: Terrain ETL- 0428 1986 and Object Modeling Recognition (March 13, 1985 - March 13, 1986) Knowledge-Based Vision Techniques - Task B: Terrain ETL

The Importance of Practice in the Development of Statistics.

DTIC Science & Technology

1983-01-01

RESOLUTION TEST CHART NATIONAL BUREAU OIF STANDARDS 1963 -A NRC Technical Summary Report #2471 C THE IMORTANCE OF PRACTICE IN to THE DEVELOPMENT OF STATISTICS...component analysis, bioassay, limits for a ratio, quality control, sampling inspection, non-parametric tests , transformation theory, ARIMA time series...models, sequential tests , cumulative sum charts, data analysis plotting techniques, and a resolution of the Bayes - frequentist controversy. It appears

What the Pendulum Can Tell Educators about Children's Scientific Reasoning

NASA Astrophysics Data System (ADS)

Stafford, Erin

2004-11-01

Inhelder and Piaget (1958) studied schoolchildren's understanding of a simplependulum as a means of investigating the development of the control of variablesscheme and the ceteris paribus principle central to scientific experimentation.The time-consuming nature of the individual interview technique used by Inhelderhas led to the development of a whole range of group test techniques aimed attesting the empirical validity and increasing the practical utility of Piaget's work.The Rasch measurement techniques utilized in this study reveal that the Piagetian Reasoning Task III — Pendulum and the méthode clinique interview revealthe same underlying ability. Of particular interest to classroom teachers is theevidence that some individuals produced rather disparate performances across thetwo testing situations. The implications of the commonalities and individualdifferences in performance for interpreting children's scientific understanding arediscussed.

The Design and Development of Test Platform for Wheat Precision Seeding Based on Image Processing Techniques

NASA Astrophysics Data System (ADS)

Li, Qing; Lin, Haibo; Xiu, Yu-Feng; Wang, Ruixue; Yi, Chuijie

The test platform of wheat precision seeding based on image processing techniques is designed to develop the wheat precision seed metering device with high efficiency and precision. Using image processing techniques, this platform gathers images of seeds (wheat) on the conveyer belt which are falling from seed metering device. Then these data are processed and analyzed to calculate the qualified rate, reseeding rate and leakage sowing rate, etc. This paper introduces the whole structure, design parameters of the platform and hardware & software of the image acquisition system were introduced, as well as the method of seed identification and seed-space measurement using image's threshold and counting the seed's center. By analyzing the experimental result, the measurement error is less than ± 1mm.

PM-1 NUCLEAR POWER PLANT PROGRAM. Quarterly Progress Report No. 2 for June 1 to August 31, 1959

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

Sieg, J.S.; Smith, E.H.

1959-10-01

The objective of the contract is the design, development, fabrication, installation, and initial testing and operation of a prepackaged air- transportable pressurized water reactor nuclear power plant, the PM-1. The specified output is 1 Mwe and 7 million Btu/hr of heat. The plant is to be operational by March 1962. The principal efforts were completion of the plant parametric study and preparation of the preliminary design. A summary of design parameters is given. Systems development work included study and selection of packages for full-scale testing, a survey of in-core instrumentation techniques, control and instrumentation development, and development of components formore » the steam generator, condenser, and turbine generator, which are not commercially available. Reactor development work included completion of the parametric zeropower experiments and preparrtions for a flexible zeropower test program, a revision of plans for irradiation testing PM-1 fuel elements, initiation of a reactor flow test program, outliring of a heat tnansfer test program, completion of the seven-tube test section (SETCH-1) tests, and evaluation of control rod actuators leading to specification of a magnetic jack-type control rod drive similar to that reported in ANL-5768. Completion of the prelimirary design led to initiation of the final design effort, which will be the principal activity during the next two project quarters. Preparations for core fabrication included procurement of core cladding material for the zero-power teat core, arrangement with a subcontractor to convent UF/sub 6/ to UO/sub 2/ and to commence delivery of the oxide during the next quarter, development of fuel element fabrication and ultrasonic testing techniques, study of control rod materials, UO/sub 2/ recovery techniques, and boron analysis methods. Preliminary work on site preparation was pursued with receipt of USAEC approval for a location on the eastern slope of Warren Peak at Sundance, Wyoming. A survey of this site is underway. A preliminary Hazards Summary Report is in preparation. (For preceding period see MND-M-1812.) (auth)« less

Next Generation LOCAD-PTS Cartridge Development

NASA Technical Reports Server (NTRS)

Morris, H.; Nutter, D.; Weite, E.; Wells, M.; Maule, J.; Damon, M.; Monaco, L.; Steele, A.; Wainwright, N.

2008-01-01

Future astrobiology exploration missions will require rapid, point-of-use techniques for surface science experiments and contamination monitoring. The Lab-On-a-Chip Application Development (LOCAD) team is developing operational instruments that advance spaceflight technologies to molecular-based methods. Currently, LOCAD-Portable Test System (PTS) is quantifying levels of the bacterial molecule endotoxin onboard the Internatioal Space Station. Future research and development will focus on more sensitive molecular techniques that expand the number of compounds detected to include beta-glucan from fungal cell walls.

A NASA Perspective and Validation and Testing of Design Hardening for the Natural Space Radiation Environment (GOMAC Tech 03)

NASA Technical Reports Server (NTRS)

Day, John H. (Technical Monitor); LaBel, Kenneth A.; Howard, James W.; Carts, Martin A.; Seidleck, Christine

2003-01-01

With the dearth of dedicated radiation hardened foundries, new and novel techniques are being developed for hardening designs using non-dedicated foundry services. In this paper, we will discuss the implications of validating these methods for the natural space radiation environment issues: total ionizing dose (TID) and single event effects (SEE). Topics of discussion include: Types of tests that are required, Design coverage (i.e., design libraries: do they need validating for each application?) A new task within NASA to compare existing design. This latter task is a new effort in FY03 utilizing a 8051 microcontroller core from multiple design hardening developers as a test vehicle to evaluate each mitigative technique.

Developing an economical and reliable test for measuring the resilient modulus and Poisson's ratio of subgrade.

DOT National Transportation Integrated Search

2010-11-01

The resilient modulus and Poissons ratio of base and sublayers in highway use are : important parameters in design and quality control process. The currently used techniques : include CBR (California Bearing Ratio) test, resilient modulus test,...

The development of an audit technique to assess the quality of safety barrier management.

PubMed

Guldenmund, Frank; Hale, Andrew; Goossens, Louis; Betten, Jeroen; Duijm, Nijs Jan

2006-03-31

This paper describes the development of a management model to control barriers devised to prevent major hazard scenarios. Additionally, an audit technique is explained that assesses the quality of such a management system. The final purpose of the audit technique is to quantify those aspects of the management system that have a direct impact on the reliability and effectiveness of the barriers and, hence, the probability of the scenarios involved. First, an outline of the management model is given and its elements are explained. Then, the development of the audit technique is described. Because the audit technique uses actual major hazard scenarios and barriers within these as its focus, the technique achieves a concreteness and clarity that many other techniques often lack. However, this strength is also its limitation, since the full safety management system is not covered with the technique. Finally, some preliminary experiences obtained from several test sites are compiled and discussed.

Aircraft lightning-induced voltage test technique developments

NASA Technical Reports Server (NTRS)

Crouch, K. E.

1983-01-01

High voltage safety, fuels safety, simulation, and response/measurement techniques are discussed. Travelling wave transit times, return circuit conductor configurations, LC ladder network generators, and repetitive pulse techniques are also discussed. Differential conductive coaxial cable, analog fiber optic link, repetitive pulse sampled data instrumentation system, flash A/D optic link system, and an FM telemetry system are considered.

Simulation verification techniques study

NASA Technical Reports Server (NTRS)

Schoonmaker, P. B.; Wenglinski, T. H.

1975-01-01

Results are summarized of the simulation verification techniques study which consisted of two tasks: to develop techniques for simulator hardware checkout and to develop techniques for simulation performance verification (validation). The hardware verification task involved definition of simulation hardware (hardware units and integrated simulator configurations), survey of current hardware self-test techniques, and definition of hardware and software techniques for checkout of simulator subsystems. The performance verification task included definition of simulation performance parameters (and critical performance parameters), definition of methods for establishing standards of performance (sources of reference data or validation), and definition of methods for validating performance. Both major tasks included definition of verification software and assessment of verification data base impact. An annotated bibliography of all documents generated during this study is provided.

Effects of cosmic rays on single event upsets

NASA Technical Reports Server (NTRS)

Venable, D. D.; Zajic, V.; Lowe, C. W.; Olidapupo, A.; Fogarty, T. N.

1989-01-01

Assistance was provided to the Brookhaven Single Event Upset (SEU) Test Facility. Computer codes were developed for fragmentation and secondary radiation affecting Very Large Scale Integration (VLSI) in space. A computer controlled CV (HP4192) test was developed for Terman analysis. Also developed were high speed parametric tests which are independent of operator judgment and a charge pumping technique for measurement of D(sub it) (E). The X-ray secondary effects, and parametric degradation as a function of dose rate were simulated. The SPICE simulation of static RAMs with various resistor filters was tested.

Ultrasonic technique for measuring porosity of plasma-sprayed alumina coatings

NASA Astrophysics Data System (ADS)

Parthasarathi, S.; Tittmann, B. R.; Onesto, E. J.

1997-12-01

Porosity is an important factor in plasma-sprayed coatings, especially ceramic coatings. Excessive poros-ity can adversely affect the performance of the coated component in various ways. An ultrasonic nonde-structive measurement technique has been developed to measure porosity in plasma-sprayed alumina coatings. The technique is generic and can be extended to other ceramic coating systems. To test the tech-nique, freestanding alumina coatings with varying levels of porosity were fabricated via plasma spray. Samples with varying porosity, obtained through innovative fabrication techniques, were used to gener-ate a calibration curve. The ultrasonic velocity in the low-frequency range was found to be dependent on the density of freestanding coatings (measured via Archimedian techniques). This dependence is the basis of the development of a technique to measure the density of coatings.

Fuel containment, lightning protection and damage tolerance in large composite primary aircraft structures

NASA Technical Reports Server (NTRS)

Griffin, Charles F.; James, Arthur M.

1985-01-01

The damage-tolerance characteristics of high strain-to-failure graphite fibers and toughened resins were evaluated. Test results show that conventional fuel tank sealing techniques are applicable to composite structures. Techniques were developed to prevent fuel leaks due to low-energy impact damage. For wing panels subjected to swept stroke lightning strikes, a surface protection of graphite/aluminum wire fabric and a fastener treatment proved effective in eliminating internal sparking and reducing structural damage. The technology features developed were incorporated and demonstrated in a test panel designed to meet the strength, stiffness, and damage tolerance requirements of a large commercial transport aircraft. The panel test results exceeded design requirements for all test conditions. Wing surfaces constructed with composites offer large weight savings if design allowable strains for compression can be increased from current levels.

Risk-Based Object Oriented Testing

NASA Technical Reports Server (NTRS)

Rosenberg, Linda H.; Stapko, Ruth; Gallo, Albert

2000-01-01

Software testing is a well-defined phase of the software development life cycle. Functional ("black box") testing and structural ("white box") testing are two methods of test case design commonly used by software developers. A lesser known testing method is risk-based testing, which takes into account the probability of failure of a portion of code as determined by its complexity. For object oriented programs, a methodology is proposed for identification of risk-prone classes. Risk-based testing is a highly effective testing technique that can be used to find and fix the most important problems as quickly as possible.

Plasma spectroscopy analysis technique based on optimization algorithms and spectral synthesis for arc-welding quality assurance.

PubMed

Mirapeix, J; Cobo, A; González, D A; López-Higuera, J M

2007-02-19

A new plasma spectroscopy analysis technique based on the generation of synthetic spectra by means of optimization processes is presented in this paper. The technique has been developed for its application in arc-welding quality assurance. The new approach has been checked through several experimental tests, yielding results in reasonably good agreement with the ones offered by the traditional spectroscopic analysis technique.

Application of fault detection techniques to spiral bevel gear fatigue data

NASA Technical Reports Server (NTRS)

Zakrajsek, James J.; Handschuh, Robert F.; Decker, Harry J.

1994-01-01

Results of applying a variety of gear fault detection techniques to experimental data is presented. A spiral bevel gear fatigue rig was used to initiate a naturally occurring fault and propagate the fault to a near catastrophic condition of the test gear pair. The spiral bevel gear fatigue test lasted a total of eighteen hours. At approximately five and a half hours into the test, the rig was stopped to inspect the gears for damage, at which time a small pit was identified on a tooth of the pinion. The test was then stopped an additional seven times throughout the rest of the test in order to observe and document the growth and propagation of the fault. The test was ended when a major portion of a pinion tooth broke off. A personal computer based diagnostic system was developed to obtain vibration data from the test rig, and to perform the on-line gear condition monitoring. A number of gear fault detection techniques, which use the signal average in both the time and frequency domain, were applied to the experimental data. Among the techniques investigated, two of the recently developed methods appeared to be the first to react to the start of tooth damage. These methods continued to react to the damage as the pitted area grew in size to cover approximately 75% of the face width of the pinion tooth. In addition, information gathered from one of the newer methods was found to be a good accumulative damage indicator. An unexpected result of the test showed that although the speed of the rig was held to within a band of six percent of the nominal speed, and the load within eighteen percent of nominal, the resulting speed and load variations substantially affected the performance of all of the gear fault detection techniques investigated.

Data Fusion in Wind Tunnel Testing; Combined Pressure Paint and Model Deformation Measurements (Invited)

NASA Technical Reports Server (NTRS)

Bell, James H.; Burner, Alpheus W.

2004-01-01

As the benefit-to-cost ratio of advanced optical techniques for wind tunnel measurements such as Video Model Deformation (VMD), Pressure-Sensitive Paint (PSP), and others increases, these techniques are being used more and more often in large-scale production type facilities. Further benefits might be achieved if multiple optical techniques could be deployed in a wind tunnel test simultaneously. The present study discusses the problems and benefits of combining VMD and PSP systems. The desirable attributes of useful optical techniques for wind tunnels, including the ability to accommodate the myriad optical techniques available today, are discussed. The VMD and PSP techniques are briefly reviewed. Commonalties and differences between the two techniques are discussed. Recent wind tunnel experiences and problems when combining PSP and VMD are presented, as are suggestions for future developments in combined PSP and deformation measurements.

NDE of ceramics and ceramic composites

NASA Technical Reports Server (NTRS)

Vary, Alex; Klima, Stanley J.

1991-01-01

Although nondestructive evaluation (NDE) techniques for ceramics are fairly well developed, they are difficult to apply in many cases for high probability detection of the minute flaws that can cause failure in monolithic ceramics. Conventional NDE techniques are available for monolithic and fiber reinforced ceramic matrix composites, but more exact quantitative techniques needed are still being investigated and developed. Needs range from flaw detection to below 100 micron levels in monolithic ceramics to global imaging of fiber architecture and matrix densification anomalies in ceramic composites. NDE techniques that will ultimately be applicable to production and quality control of ceramic structures are still emerging from the lab. Needs are different depending on the processing stage, fabrication method, and nature of the finished product. NDE techniques are being developed in concert with materials processing research where they can provide feedback information to processing development and quality improvement. NDE techniques also serve as research tools for materials characterization and for understanding failure processes, e.g., during thermomechanical testing.

Measuring Attending Behavior and Short-Term Memory with Knox's Cube Test.

ERIC Educational Resources Information Center

Stone, Mark H.; Wright, Benjamin D.

1983-01-01

A new revision was developed using Rasch psychometric techniques to build a Knox's Cube Test (KCT) variable and item bank using the tapping series from all previous editions. The report forms developed give a clear picture of the subject's performance set in a context that is both normative and criterion. (Author/BW)

Using Logistic Approximations of Marginal Trace Lines to Develop Short Assessments

ERIC Educational Resources Information Center

Stucky, Brian D.; Thissen, David; Edelen, Maria Orlando

2013-01-01

Test developers often need to create unidimensional scales from multidimensional data. For item analysis, "marginal trace lines" capture the relation with the general dimension while accounting for nuisance dimensions and may prove to be a useful technique for creating short-form tests. This article describes the computations needed to obtain…

Flight Test Validation of Optimal Input Design and Comparison to Conventional Inputs

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

1997-01-01

A technique for designing optimal inputs for aerodynamic parameter estimation was flight tested on the F-18 High Angle of Attack Research Vehicle (HARV). Model parameter accuracies calculated from flight test data were compared on an equal basis for optimal input designs and conventional inputs at the same flight condition. In spite of errors in the a priori input design models and distortions of the input form by the feedback control system, the optimal inputs increased estimated parameter accuracies compared to conventional 3-2-1-1 and doublet inputs. In addition, the tests using optimal input designs demonstrated enhanced design flexibility, allowing the optimal input design technique to use a larger input amplitude to achieve further increases in estimated parameter accuracy without departing from the desired flight test condition. This work validated the analysis used to develop the optimal input designs, and demonstrated the feasibility and practical utility of the optimal input design technique.

Incipient- and Developed-Spin and Recovery Characteristics of a Modern High-Speed Fighter Design with Low Aspect Ratio as Determined from Dynamic-Model Tests

NASA Technical Reports Server (NTRS)

Lee, Henry A.; Libbey, Charles E.

1961-01-01

Incipient- and developed-spin and recovery characteristics of a modern high-speed fighter design with low aspect ratio have been investigated by means of dynamic model tests. A 1/7-scale radio-controlled model was tested by means of drop tests from a helicopter. Several 1/25-scale models with various configuration changes were tested in the Langley 20-foot free-spinning tunnel. Model results indicated that generally it would be difficult to obtain a developed spin with a corresponding airplane and that either the airplane would recover of its own accord from any poststall motion or the poststall motion could be readily terminated by proper control technique. On occasion, however, the results indicated that if a post-stall motion were allowed to continue, a fully developed spin might be obtainable from which recovery could range from rapid to no recovery at all, even when optimum control technique was used. Satisfactory recoveries could be obtained with a proper-size tail parachute or strake, application of pitching-, rolling-, or yawing-moment rockets, or sufficient differential deflection of the horizontal tail.

Feasibility study for locating archaeological village sites by satellite remote sensing techniques. [multispectral photography of Alaska

NASA Technical Reports Server (NTRS)

Cook, J. P. (Principal Investigator); Stringer, W. J.

1974-01-01

The author has identified the following significant results. The objective is to determine the feasibility of detecting large Alaskan archaeological sites by satellite remote sensing techniques and mapping such sites. The approach used is to develop digital multispectral signatures of dominant surface features including vegetation, exposed soils and rock, hydrological patterns and known archaeological sites. ERTS-1 scenes are then printed out digitally in a map-like array with a letter reflecting the most appropriate classification representing each pixel. Preliminary signatures were developed and tested. It was determined that there was a need to tighten up the archaeological site signature by developing accurate signatures for all naturally-occurring vegetation and surface conditions in the vicinity of the test area. These second generation signatures have been tested by means of computer printouts and classified tape displays on the University of Alaska CDU-200 and by comparison with aerial photography. It has been concluded that the archaeological signatures now in use are as good as can be developed. Plans are to print out signatures for the entire test area and locate on topographic maps the likely locations of archaeological sites within the test area.

Efficient Testing Combining Design of Experiment and Learn-to-Fly Strategies

NASA Technical Reports Server (NTRS)

Murphy, Patrick C.; Brandon, Jay M.

2017-01-01

Rapid modeling and efficient testing methods are important in a number of aerospace applications. In this study efficient testing strategies were evaluated in a wind tunnel test environment and combined to suggest a promising approach for both ground-based and flight-based experiments. Benefits of using Design of Experiment techniques, well established in scientific, military, and manufacturing applications are evaluated in combination with newly developing methods for global nonlinear modeling. The nonlinear modeling methods, referred to as Learn-to-Fly methods, utilize fuzzy logic and multivariate orthogonal function techniques that have been successfully demonstrated in flight test. The blended approach presented has a focus on experiment design and identifies a sequential testing process with clearly defined completion metrics that produce increased testing efficiency.

Black Box Testing: Experiments with Runway Incursion Advisory Alerting System

NASA Technical Reports Server (NTRS)

Mukkamala, Ravi

2005-01-01

This report summarizes our research findings on the Black box testing of Runway Incursion Advisory Alerting System (RIAAS) and Runway Safety Monitor (RSM) system. Developing automated testing software for such systems has been a problem because of the extensive information that has to be processed. Customized software solutions have been proposed. However, they are time consuming to develop. Here, we present a less expensive, and a more general test platform that is capable of performing complete black box testing. The technique is based on the classification of the anomalies that arise during Monte Carlo simulations. In addition, we also discuss a generalized testing tool (prototype) that we have developed.

Development of Background-Oriented Schlieren for NASA Langley Research Center Ground Test Facilities

NASA Technical Reports Server (NTRS)

Bathel, Brett F.; Borg, Stephen; Jones, Stephen; Overmeyer, Austin; Walker, Eric; Goad, William; Clem, Michelle; Schairer, Edward T.; Mizukaki, Toshiharu

2015-01-01

This paper provides an overview of recent wind tunnel tests performed at the NASA Langley Research Center where the Background-Oriented Schlieren (BOS) technique was used to provide information pertaining to flow-field density disturbances. The facilities in which the BOS technique was applied included the National Transonic Facility (NTF), Transonic Dynamics Tunnel (TDT), 31-Inch Mach 10 Air Tunnel, 15-Inch Mach 6 High-Temperature Air Tunnel, Rotor Test Cell at the 14 by 22 Subsonic Tunnel, and a 13-Inch Low-Speed Tunnel.

Miniature bulge test and energy release rate in HIPed aluminum/aluminum interfacial fracture

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

Liu, C.; Lovato, M. L.; Clarke, K. D.

We summarize the development of a technique of using miniature bulge test combined with three-dimensional digital image correlation (3D-DIC) for measuring energy release rate or fracture toughness of bimaterial interface of thin metal foils. Furthermore, the energy release rate associated with the HIPed aluminum/aluminum interfacial delamination is determined experimentally using the proposed technique. Detailed discussions of the schemes of preparing and conducting the bulge test, and computing various quantities required for the determination of the energy release rate are presented.

Miniature bulge test and energy release rate in HIPed aluminum/aluminum interfacial fracture

DOE PAGES

Liu, C.; Lovato, M. L.; Clarke, K. D.; ...

2017-10-13

We summarize the development of a technique of using miniature bulge test combined with three-dimensional digital image correlation (3D-DIC) for measuring energy release rate or fracture toughness of bimaterial interface of thin metal foils. Furthermore, the energy release rate associated with the HIPed aluminum/aluminum interfacial delamination is determined experimentally using the proposed technique. Detailed discussions of the schemes of preparing and conducting the bulge test, and computing various quantities required for the determination of the energy release rate are presented.

Data Analysis Techniques for a Lunar Surface Navigation System Testbed

NASA Technical Reports Server (NTRS)

Chelmins, David; Sands, O. Scott; Swank, Aaron

2011-01-01

NASA is interested in finding new methods of surface navigation to allow astronauts to navigate on the lunar surface. In support of the Vision for Space Exploration, the NASA Glenn Research Center developed the Lunar Extra-Vehicular Activity Crewmember Location Determination System and performed testing at the Desert Research and Technology Studies event in 2009. A significant amount of sensor data was recorded during nine tests performed with six test subjects. This paper provides the procedure, formulas, and techniques for data analysis, as well as commentary on applications.

The concurrent use of three implicit measures (eye movements, pupillometry, and event-related potentials) to assess receptive vocabulary knowledge in normal adults.

PubMed

Ledoux, Kerry; Coderre, Emily; Bosley, Laura; Buz, Esteban; Gangopadhyay, Ishanti; Gordon, Barry

2016-03-01

Recent years have seen the advent and proliferation of the use of implicit techniques to study learning and cognition. One such application is the use of event-related potentials (ERPs) to assess receptive vocabulary knowledge. Other implicit assessment techniques that may be well-suited to other testing situations or to use with varied participant groups have not been used as widely to study receptive vocabulary knowledge. We sought to develop additional implicit techniques to study receptive vocabulary knowledge that could augment the knowledge gained from the use of the ERP technique. Specifically, we used a simple forced-choice paradigm to assess receptive vocabulary knowledge in normal adult participants using eye movement monitoring (EM) and pupillometry. In the same group of participants, we also used an N400 semantic incongruity ERP paradigm to assess their knowledge of two groups of words: those expected to be known to the participants (high-frequency, familiar words) and those expected to be unknown (low-frequency, unfamiliar words). All three measures showed reliable differences between the known and unknown words. EM and pupillometry thus may provide insight into receptive vocabulary knowledge similar to that from ERPs. The development of additional implicit assessment techniques may increase the feasibility of receptive vocabulary testing across a wider range of participant groups and testing situations, and may make the conduct of such testing more accessible to a wider range of researchers, clinicians, and educators.

Antarctic Testing of the European Ultrasonic Planetary Core Drill (UPCD)

NASA Astrophysics Data System (ADS)

Timoney, R.; Worrall, K.; Li, X.; Firstbrook, D.; Harkness, P.

2018-04-01

An overview of a series of field testing in Antarctica where the Ultrasonic Planetary Core Drill (UPCD) architecture was tested. The UPCD system is the product an EC FP7 award to develop a Mars Sample Return architecture based around the ultrasonic technique.

Nondestructive testing of railroad wheels and rails by ultrasonics

NASA Technical Reports Server (NTRS)

Clotfelter, W. M.; Risch, E. R.

1974-01-01

Quality control of wheels and rails can be improved by using ultrasonic technique developed for measuring stresses in metallic materials. In addition, parts already in use can be tested and replaced if they are found to be unsafe. Test equipment includes two transducers.

Blade pressure measurements

NASA Astrophysics Data System (ADS)

Chivers, J. W. H.

Three measurement techniques which enable rotating pressures to be measured during the normal operation of a gas turbine or a component test rig are described. The first technique was developed specifically to provide steady and transient blade surface pressure data to aid both fan flutter research and general fan performance development. This technique involves the insertion of miniature high frequency response pressure transducers into the fan blades of a large civil gas turbine. The other two techniques were developed to measure steady rotating pressures inside and on the surface of engine or rig turbine blades and also rotating pressures in cooling feed systems. These two low frequency response systems are known as the "pressure pineapple' (a name which resulted from the shape of the original prototype) and the rotating scanivalve.

A perspective of laminar-flow control. [aircraft energy efficiency program

NASA Technical Reports Server (NTRS)

Braslow, A. L.; Muraca, R. J.

1978-01-01

A historical review of the development of laminar flow control technology is presented with reference to active laminar boundary-layer control through suction, the use of multiple suction slots, wind-tunnel tests, continuous suction, and spanwise contamination. The ACEE laminar flow control program is outlined noting the development of three-dimensional boundary-layer codes, cruise-noise prediction techniques, airfoil development, and leading-edge region cleaning. Attention is given to glove flight tests and the fabrication and testing of wing box designs.

Automation of Flight Software Regression Testing

NASA Technical Reports Server (NTRS)

Tashakkor, Scott B.

2016-01-01

NASA is developing the Space Launch System (SLS) to be a heavy lift launch vehicle supporting human and scientific exploration beyond earth orbit. SLS will have a common core stage, an upper stage, and different permutations of boosters and fairings to perform various crewed or cargo missions. Marshall Space Flight Center (MSFC) is writing the Flight Software (FSW) that will operate the SLS launch vehicle. The FSW is developed in an incremental manner based on "Agile" software techniques. As the FSW is incrementally developed, testing the functionality of the code needs to be performed continually to ensure that the integrity of the software is maintained. Manually testing the functionality on an ever-growing set of requirements and features is not an efficient solution and therefore needs to be done automatically to ensure testing is comprehensive. To support test automation, a framework for a regression test harness has been developed and used on SLS FSW. The test harness provides a modular design approach that can compile or read in the required information specified by the developer of the test. The modularity provides independence between groups of tests and the ability to add and remove tests without disturbing others. This provides the SLS FSW team a time saving feature that is essential to meeting SLS Program technical and programmatic requirements. During development of SLS FSW, this technique has proved to be a useful tool to ensure all requirements have been tested, and that desired functionality is maintained, as changes occur. It also provides a mechanism for developers to check functionality of the code that they have developed. With this system, automation of regression testing is accomplished through a scheduling tool and/or commit hooks. Key advantages of this test harness capability includes execution support for multiple independent test cases, the ability for developers to specify precisely what they are testing and how, the ability to add automation, and the ability of the harness and cases to be executed continually. This test concept is an approach that can be adapted to support other projects.

10.3 High-temperature Instrumentation

NASA Technical Reports Server (NTRS)

Piazza, Anthony

2008-01-01

This viewgraph presentation describes high temperature instrumentation development from 1960-1970, 1980-1990 and 2000-present. The contents include: 1) Background; 2) Objective; 3) Application and Sensor; 4) Attachment Techniques; 5) Evaluation/Characterization Testing; and 6) Future testing.

Development of flexural vibration inspection techniques to rapidly assess the structural health of timber bridge systems

Treesearch

Xiping Wang; James P. Wacker; Robert J. Ross; Brian K. Brashaw; Robert Vatalaro

2005-01-01

This paper describes an effort to develop a global dynamic testing technique for evaluating the overall stiffness of timber bridge superstructures. A forced vibration method was used to measure the natural frequency of single-span timber bridges in the laboratory and field. An analytical model based on simple beam theory was proposed to represent the relationship...

Review of optical freeform surface representation technique and its application

NASA Astrophysics Data System (ADS)

Ye, Jingfei; Chen, Lu; Li, Xinhua; Yuan, Qun; Gao, Zhishan

2017-11-01

Modern advanced manufacturing and testing technologies allow the application of freeform optical elements. Compared with traditional spherical surfaces, an optical freeform surface has more degrees of freedom in optical design and provides substantially improved imaging performance. In freeform optics, the representation technique of a freeform surface has been a fundamental and key research topic in recent years. Moreover, it has a close relationship with other aspects of the design, manufacturing, testing, and application of optical freeform surfaces. Improvements in freeform surface representation techniques will make a significant contribution to the further development of freeform optics. We present a detailed review of the different types of optical freeform surface representation techniques and their applications and discuss their properties and differences. Additionally, we analyze the future trends of optical freeform surface representation techniques.

Saturn S-2 quality assurance techniques: Nondestructive testing processes. Volume 1: Requirements and procedures

NASA Technical Reports Server (NTRS)

Eller, H. H.; Sugg, F. E.

1970-01-01

The methods and procedures used to perform nondestructive testing inspections of the Saturn S-2 liquid hydrogen and liquid oxygen tank weldments during fabrication and after proof testing are described to document special skills developed during the program. All post-test inspection requirements are outlined including radiographic inspections procedures.

Test of Economic Literacy: Discussion Guide and Rationale.

ERIC Educational Resources Information Center

Soper, John C.

Part of a series which offers educational resources and teaching techniques related to major social issues to high school social studies teachers, the booklet describes and reproduces a test measuring students' economic literacy. Part I is the test manual, which explains the objectives, value, development, and two-form structure of the test. It…

The effect of sea-water and fresh-water soaking on the hedonic test of Eucheuma sp. syrup and pudding

NASA Astrophysics Data System (ADS)

Novianty, H.; Herandarudewi, S. M. C.

2018-04-01

Seaweed is a non-fishery marine commodity that has great opportunities to be developed in Indonesia. One of the seaweed with a high economic value is Eucheuma alvarezii. This seaweed can be used as an additional material in cosmetic and pharmaceutical products or directly used for syrup and pudding. Post-harvest technique conducted by the seaweed farmers will affects the quality of dried and processed products. The purpose of this study is to see the effect of post harvest technique on the quality of dried seaweed and hedonic test (favorable test) of processed product (syrup and pudding). This study was conducted using descriptive method. The study compared dried, syrup, and puddings from two differents post-harvest technique, between salt and fresh-water draining products. The results showed that fresh-water draining technique obtained better quality results organoleptic test. Supported by hedonic test, that showed more panelists were prefered the fresh-water drained products of syrup and pudding. The preference were much higher for the fresh-water drained products in all three catagories of color, taste, and smell.

Accelerated testing of space mechanisms

NASA Technical Reports Server (NTRS)

Murray, S. Frank; Heshmat, Hooshang

1995-01-01

This report contains a review of various existing life prediction techniques used for a wide range of space mechanisms. Life prediction techniques utilized in other non-space fields such as turbine engine design are also reviewed for applicability to many space mechanism issues. The development of new concepts on how various tribological processes are involved in the life of the complex mechanisms used for space applications are examined. A 'roadmap' for the complete implementation of a tribological prediction approach for complex mechanical systems including standard procedures for test planning, analytical models for life prediction and experimental verification of the life prediction and accelerated testing techniques are discussed. A plan is presented to demonstrate a method for predicting the life and/or performance of a selected space mechanism mechanical component.

Dual resin bonded joints in polyetheretherketone (PEEK) matrix composites

NASA Astrophysics Data System (ADS)

Zelenak, Steve; Radford, Donald W.; Dean, Michael W.

1993-04-01

The paper describes applications of the dual resin (miscible polymer) bonding technique (Smiley, 1989) developed as an alternative to traditional bonding approaches to joining thermoplastic matrix composite subassemblies into structures. In the experiments, the performance of joint geometries, such as those that could be used to assemble large truss structures in space, are investigated using truss joint models consisting of woven carbon fiber/PEEK tubes of about 1 mm wall thickness. Specific process conditions and hand-held hardware used to apply heat and pressure were chosen to simulate a field asembly technique. Results are presented on tube/cruciform double lap shear tests, pinned-pinned tube compression tests, and single lap shear bond tests of joints obtained using the dual resin bonding technique.

Development of advanced diagnostics for characterization of burning droplets in microgravity

NASA Technical Reports Server (NTRS)

Sankar, Subramanian; Buermann, Dale H.; Bachalo, William D.

1995-01-01

Diagnostic techniques currently used for microgravity research are generally not as advanced as those used in earth based gravity experiments. Diagnostic techniques for measuring the instantaneous radial temperature profile (or temperature gradients) within the burning droplet do not exist. Over the past few years, Aerometrics has been researching and developing a rainbow thermometric technique for measuring the droplet temperatures of burning droplets. This technique has recently been integrated with the phase Doppler interferometric technique to yield a diagnostic instrument that can be used to simultaneously measure the size, velocity, and temperature of burning droplets in complex spray flames. Also, the rainbow thermometric technique has been recently integrated with a point-diffraction interferometric technique for measuring the instantaneous gas phase temperature field surrounding a burning droplet. These research programs, apart from being very successful, have also helped us identify other innovative techniques for the characterization of burning droplets. For example, new techniques have been identified for measuring the instantaneous regression rate of burning droplets. Also, there is the possibility of extracting the instantaneous radial temperature distribution or the temperature gradients within a droplet during transient heating. What is important is that these diagnostic techniques have the potential for making use of inexpensive, light-weight, and rugged devices such as diode lasers and linear CCD arrays. As a result, they can be easily packaged for incorporation into microgravity drop-test and flight-test facilities. Furthermore, with the use of linear CCD arrays, data rates as high as 10-100 kHz can be easily achieved. This data rate is orders of magnitude higher than what is currently achievable. In this research and development program, a compact and rugged diagnostic system will be developed that can be used to measure instantaneous fuel droplet diameter, droplet regression rate, and the droplet internal temperature profiles or gradients at very high data rates in microgravity experiments.

Dimpled ball grid array process development for space flight applications

NASA Technical Reports Server (NTRS)

Barr, S. L.; Mehta, A.

2000-01-01

A 472 dimpled ball grid array (D-BGA) package has not been used in past space flight environments, therefore it was necessary to develop a process that would yield robust and reliable solder joints. The process developing assembly, inspection and rework techniques, were verified by conducting environmental tests. Since the 472 D-BGA packages passed the above environmental tests within the specifications, the process was successfully developed for space flight electronics.

Nondestructive analysis and development

NASA Technical Reports Server (NTRS)

Moslehy, Faissal A.

1993-01-01

This final report summarizes the achievements of project #4 of the NASA/UCF Cooperative Agreement from January 1990 to December 1992. The objectives of this project are to review NASA's NDE program at Kennedy Space Center (KSC) and recommend means for enhancing the present testing capabilities through the use of improved or new technologies. During the period of the project, extensive development of a reliable nondestructive, non-contact vibration technique to determine and quantify the bond condition of the thermal protection system (TPS) tiles of the Space Shuttle Orbiter was undertaken. Experimental modal analysis (EMA) is used as a non-destructive technique for the evaluation of Space Shuttle thermal protection system (TPS) tile bond integrity. Finite element (FE) models for tile systems were developed and were used to generate their vibration characteristics (i.e. natural frequencies and mode shapes). Various TPS tile assembly configurations as well as different bond conditions were analyzed. Results of finite element analyses demonstrated a drop in natural frequencies and a change in mode shapes which correlate with both size and location of disbond. Results of experimental testing of tile panels correlated with FE results and demonstrated the feasibility of EMA as a viable technique for tile bond verification. Finally, testing performed on the Space Shuttle Columbia using a laser doppler velocimeter demonstrated the application of EMA, when combined with FE modeling, as a non-contact, non-destructive bond evaluation technique.

Development of a Perfectly Matched Layer Technique for a Discontinuous-Galerkin Spectral-Element Method

NASA Technical Reports Server (NTRS)

Garai, Anirban; Diosady, Laslo T.; Murman, Scott M.; Madavan, Nateri K.

2016-01-01

The perfectly matched layer (PML) technique is developed in the context of a high- order spectral-element Discontinuous-Galerkin (DG) method. The technique is applied to a range of test cases and is shown to be superior compared to other approaches, such as those based on using characteristic boundary conditions and sponge layers, for treating the inflow and outflow boundaries of computational domains. In general, the PML technique improves the quality of the numerical results for simulations of practical flow configurations, but it also exhibits some instabilities for large perturbations. A preliminary analysis that attempts to understand the source of these instabilities is discussed.

Inversion of particle-size distribution from angular light-scattering data with genetic algorithms.

PubMed

Ye, M; Wang, S; Lu, Y; Hu, T; Zhu, Z; Xu, Y

1999-04-20

A stochastic inverse technique based on a genetic algorithm (GA) to invert particle-size distribution from angular light-scattering data is developed. This inverse technique is independent of any given a priori information of particle-size distribution. Numerical tests show that this technique can be successfully applied to inverse problems with high stability in the presence of random noise and low susceptibility to the shape of distributions. It has also been shown that the GA-based inverse technique is more efficient in use of computing time than the inverse Monte Carlo method recently developed by Ligon et al. [Appl. Opt. 35, 4297 (1996)].

Test techniques: A survey paper on cryogenic tunnels, adaptive wall test sections, and magnetic suspension and balance systems

NASA Technical Reports Server (NTRS)

Kilgore, Robert A.; Dress, David A.; Wolf, Stephen W. D.; Britcher, Colin P.

1989-01-01

The ability to get good experimental data in wind tunnels is often compromised by things seemingly beyond our control. Inadequate Reynolds number, wall interference, and support interference are three of the major problems in wind tunnel testing. Techniques for solving these problems are available. Cryogenic wind tunnels solve the problem of low Reynolds number. Adaptive wall test sections can go a long way toward eliminating wall interference. A magnetic suspension and balance system (MSBS) completely eliminates support interference. Cryogenic tunnels, adaptive wall test sections, and MSBS are surveyed. A brief historical overview is given and the present state of development and application in each area is described.

Density-based empirical likelihood procedures for testing symmetry of data distributions and K-sample comparisons.

PubMed

Vexler, Albert; Tanajian, Hovig; Hutson, Alan D

In practice, parametric likelihood-ratio techniques are powerful statistical tools. In this article, we propose and examine novel and simple distribution-free test statistics that efficiently approximate parametric likelihood ratios to analyze and compare distributions of K groups of observations. Using the density-based empirical likelihood methodology, we develop a Stata package that applies to a test for symmetry of data distributions and compares K -sample distributions. Recognizing that recent statistical software packages do not sufficiently address K -sample nonparametric comparisons of data distributions, we propose a new Stata command, vxdbel, to execute exact density-based empirical likelihood-ratio tests using K samples. To calculate p -values of the proposed tests, we use the following methods: 1) a classical technique based on Monte Carlo p -value evaluations; 2) an interpolation technique based on tabulated critical values; and 3) a new hybrid technique that combines methods 1 and 2. The third, cutting-edge method is shown to be very efficient in the context of exact-test p -value computations. This Bayesian-type method considers tabulated critical values as prior information and Monte Carlo generations of test statistic values as data used to depict the likelihood function. In this case, a nonparametric Bayesian method is proposed to compute critical values of exact tests.

Summary of CPAS EDU Testing Analysis Results

NASA Technical Reports Server (NTRS)

Romero, Leah M.; Bledsoe, Kristin J.; Davidson, John.; Engert, Meagan E.; Fraire, Usbaldo, Jr.; Galaviz, Fernando S.; Galvin, Patrick J.; Ray, Eric S.; Varela, Jose

2015-01-01

The Orion program's Capsule Parachute Assembly System (CPAS) project is currently conducting its third generation of testing, the Engineering Development Unit (EDU) series. This series utilizes two test articles, a dart-shaped Parachute Compartment Drop Test Vehicle (PCDTV) and capsule-shaped Parachute Test Vehicle (PTV), both of which include a full size, flight-like parachute system and require a pallet delivery system for aircraft extraction. To date, 15 tests have been completed, including six with PCDTVs and nine with PTVs. Two of the PTV tests included the Forward Bay Cover (FBC) provided by Lockheed Martin. Advancements in modeling techniques applicable to parachute fly-out, vehicle rate of descent, torque, and load train, also occurred during the EDU testing series. An upgrade from a composite to an independent parachute simulation allowed parachute modeling at a higher level of fidelity than during previous generations. The complexity of separating the test vehicles from their pallet delivery systems necessitated the use the Automatic Dynamic Analysis of Mechanical Systems (ADAMS) simulator for modeling mated vehicle aircraft extraction and separation. This paper gives an overview of each EDU test and summarizes the development of CPAS analysis tools and techniques during EDU testing.

Evaluation of small area crop estimation techniques using LANDSAT- and ground-derived data. [South Dakota

NASA Technical Reports Server (NTRS)

Amis, M. L.; Martin, M. V.; Mcguire, W. G.; Shen, S. S. (Principal Investigator)

1982-01-01

Studies completed in fiscal year 1981 in support of the clustering/classification and preprocessing activities of the Domestic Crops and Land Cover project. The theme throughout the study was the improvement of subanalysis district (usually county level) crop hectarage estimates, as reflected in the following three objectives: (1) to evaluate the current U.S. Department of Agriculture Statistical Reporting Service regression approach to crop area estimation as applied to the problem of obtaining subanalysis district estimates; (2) to develop and test alternative approaches to subanalysis district estimation; and (3) to develop and test preprocessing techniques for use in improving subanalysis district estimates.

Flight test trajectory control analysis

NASA Technical Reports Server (NTRS)

Walker, R.; Gupta, N.

1983-01-01

Recent extensions to optimal control theory applied to meaningful linear models with sufficiently flexible software tools provide powerful techniques for designing flight test trajectory controllers (FTTCs). This report describes the principal steps for systematic development of flight trajectory controllers, which can be summarized as planning, modeling, designing, and validating a trajectory controller. The techniques have been kept as general as possible and should apply to a wide range of problems where quantities must be computed and displayed to a pilot to improve pilot effectiveness and to reduce workload and fatigue. To illustrate the approach, a detailed trajectory guidance law is developed and demonstrated for the F-15 aircraft flying the zoom-and-pushover maneuver.

Development of a CFD Code for Analysis of Fluid Dynamic Forces in Seals

NASA Technical Reports Server (NTRS)

Athavale, Mahesh M.; Przekwas, Andrzej J.; Singhal, Ashok K.

1991-01-01

The aim is to develop a 3-D computational fluid dynamics (CFD) code for the analysis of fluid flow in cylindrical seals and evaluation of the dynamic forces on the seals. This code is expected to serve as a scientific tool for detailed flow analysis as well as a check for the accuracy of the 2D industrial codes. The features necessary in the CFD code are outlined. The initial focus was to develop or modify and implement new techniques and physical models. These include collocated grid formulation, rotating coordinate frames and moving grid formulation. Other advanced numerical techniques include higher order spatial and temporal differencing and an efficient linear equation solver. These techniques were implemented in a 2D flow solver for initial testing. Several benchmark test cases were computed using the 2D code, and the results of these were compared to analytical solutions or experimental data to check the accuracy. Tests presented here include planar wedge flow, flow due to an enclosed rotor, and flow in a 2D seal with a whirling rotor. Comparisons between numerical and experimental results for an annular seal and a 7-cavity labyrinth seal are also included.

Wide Panel Testing Technique for Evaluating Repair Weld Strengths

NASA Technical Reports Server (NTRS)

Rogers, Patrick R.; Bynum, Julian E.; Shah, Sandeep R.

1998-01-01

This paper describes a new tensile testing technique for evaluating the overall effect of a repair weld on the strength of a welded joint. Previously, repair weld strengths have been evaluated using one-inch width tensile specimens, but this technique does not capture all of the effects that result from a repair. The new technique involves testing of "wide panel" tensile specimens which contain the full length of a repair weld within a longer initial weld, allowing the specimen to capture the combined effects of residual stresses, local strength degradation, and load redistribution around a repair. The development of strains in the repair area of standard aluminum alloy specimens and new high-performance aluminum-lithium alloy specimens was observed and evaluated using photoelastic material. The results of this evaluation show an increased sensitivity to repair welding residual stresses in the aluminum-lithium alloy specimens.

A technique for extracting blood samples from mice in fire toxicity tests

NASA Technical Reports Server (NTRS)

Bucci, T. J.; Hilado, C. J.; Lopez, M. T.

1976-01-01

The extraction of adequate blood samples from moribund and dead mice has been a problem because of the small quantity of blood in each animal and the short time available between the animals' death and coagulation of the blood. These difficulties are particularly critical in fire toxicity tests because removal of the test animals while observing proper safety precautions for personnel is time-consuming. Techniques for extracting blood samples from mice were evaluated, and a technique was developed to obtain up to 0.8 ml of blood from a single mouse after death. The technique involves rapid exposure and cutting of the posterior vena cava and accumulation of blood in the peritoneal space. Blood samples of 0.5 ml or more from individual mice have been consistently obtained as much as 16 minutes after apparent death. Results of carboxyhemoglobin analyses of blood appeared reproducible and consistent with carbon monoxide concentrations in the exposure chamber.

Microwave bale moisture sensing: Field trial

USDA-ARS?s Scientific Manuscript database

A microwave moisture measurement technique was developed for moisture sensing of cotton bales after the bale press. The technique measures the propagation delay of a microwave signal that is transmitted through the cotton bale. This research conducted a field trial to test the sensor in a commercial...

DEVELOPMENT OF AN ULTRASONIC INDIRECT BLOOD PRESSURE SENSING TECHNIQUE FOR AEROSPACE APPLICATION,

DTIC Science & Technology

with arterial opening motion, comparing systolic and diastolic pressures thus obtained to those acquired by auscultation and recording Korotkoff sounds...level airborne noise environments where auscultation techniques were not usable. Tests made with patients in shock showed performance of the

Imaging and Analysis of Void-defects in Solder Joints Formed in Reduced Gravity using High-Resolution Computed Tomography

NASA Technical Reports Server (NTRS)

Easton, John W.; Struk, Peter M.; Rotella, Anthony

2008-01-01

As a part of efforts to develop an electronics repair capability for long duration space missions, techniques and materials for soldering components on a circuit board in reduced gravity must be developed. This paper presents results from testing solder joint formation in low gravity on a NASA Reduced Gravity Research Aircraft. The results presented include joints formed using eutectic tin-lead solder and one of the following fluxes: (1) a no-clean flux core, (2) a rosin flux core, and (3) a solid solder wire with external liquid no-clean flux. The solder joints are analyzed with a computed tomography (CT) technique which imaged the interior of the entire solder joint. This replaced an earlier technique that required the solder joint to be destructively ground down revealing a single plane which was subsequently analyzed. The CT analysis technique is described and results presented with implications for future testing as well as implications for the overall electronics repair effort discussed.

Semi-Automated Pulse-Echo Ultrasonic System for Inspecting Tires

DOT National Transportation Integrated Search

1977-07-01

A nondestructive tire-testing system has been developed using the pulse-echo ultrasonic technique, which offers substantial advantages over all other physical nondestructive-testing methods and shows promise of reducing the cost of production-tire in...

Test load verification through strain data analysis

NASA Technical Reports Server (NTRS)

Verderaime, V.; Harrington, F.

1995-01-01

A traditional binding acceptance criterion on polycrystalline structures is the experimental verification of the ultimate factor of safety. At fracture, the induced strain is inelastic and about an order-of-magnitude greater than designed for maximum expected operational limit. At this extreme strained condition, the structure may rotate and displace at the applied verification load such as to unknowingly distort the load transfer into the static test article. Test may result in erroneously accepting a submarginal design or rejecting a reliable one. A technique was developed to identify, monitor, and assess the load transmission error through two back-to-back surface-measured strain data. The technique is programmed for expediency and convenience. Though the method was developed to support affordable aerostructures, the method is also applicable for most high-performance air and surface transportation structural systems.

Development of a Postacute Hospital Item Bank for the New Pediatric Evaluation of Disability Inventory-Computer Adaptive Test

ERIC Educational Resources Information Center

Dumas, Helene M.

2010-01-01

The PEDI-CAT is a new computer adaptive test (CAT) version of the Pediatric Evaluation of Disability Inventory (PEDI). Additional PEDI-CAT items specific to postacute pediatric hospital care were recently developed using expert reviews and cognitive interviewing techniques. Expert reviews established face and construct validity, providing positive…

Composite Javelin

NASA Technical Reports Server (NTRS)

1979-01-01

In the photo at right, a unique, advanced type of javelin is undergoing "flight test." The javelin was designed to meet specifications laid down by the International Amateur Athletic Federation, but it has better stability than conventional javelins, according to college athletes who tested it. Its development incorporated aerodynamic design techniques and a composite material developed by NASA's Langley Research Center for aircraft and spacecraft.

Evaluation of methods for rapid determination of freezing point of aviation fuels

NASA Technical Reports Server (NTRS)

Mathiprakasam, B.

1982-01-01

Methods for identification of the more promising concepts for the development of a portable instrument to rapidly determine the freezing point of aviation fuels are described. The evaluation process consisted of: (1) collection of information on techniques previously used for the determination of the freezing point, (2) screening and selection of these techniques for further evaluation of their suitability in a portable unit for rapid measurement, and (3) an extensive experimental evaluation of the selected techniques and a final selection of the most promising technique. Test apparatuses employing differential thermal analysis and the change in optical transparency during phase change were evaluated and tested. A technique similar to differential thermal analysis using no reference fuel was investigated. In this method, the freezing point was obtained by digitizing the data and locating the point of inflection. Results obtained using this technique compare well with those obtained elsewhere using different techniques. A conceptual design of a portable instrument incorporating this technique is presented.

Development Context Driven Change Awareness and Analysis Framework

NASA Technical Reports Server (NTRS)

Sarma, Anita; Branchaud, Josh; Dwyer, Matthew B.; Person, Suzette; Rungta, Neha

2014-01-01

Recent work on workspace monitoring allows conflict prediction early in the development process, however, these approaches mostly use syntactic differencing techniques to compare different program versions. In contrast, traditional change-impact analysis techniques analyze related versions of the program only after the code has been checked into the master repository. We propose a novel approach, De- CAF (Development Context Analysis Framework), that leverages the development context to scope a change impact analysis technique. The goal is to characterize the impact of each developer on other developers in the team. There are various client applications such as task prioritization, early conflict detection, and providing advice on testing that can benefit from such a characterization. The DeCAF framework leverages information from the development context to bound the iDiSE change impact analysis technique to analyze only the parts of the code base that are of interest. Bounding the analysis can enable DeCAF to efficiently compute the impact of changes using a combination of program dependence and symbolic execution based approaches.

Development Context Driven Change Awareness and Analysis Framework

NASA Technical Reports Server (NTRS)

Sarma, Anita; Branchaud, Josh; Dwyer, Matthew B.; Person, Suzette; Rungta, Neha; Wang, Yurong; Elbaum, Sebastian

2014-01-01

Recent work on workspace monitoring allows conflict prediction early in the development process, however, these approaches mostly use syntactic differencing techniques to compare different program versions. In contrast, traditional change-impact analysis techniques analyze related versions of the program only after the code has been checked into the master repository. We propose a novel approach, DeCAF (Development Context Analysis Framework), that leverages the development context to scope a change impact analysis technique. The goal is to characterize the impact of each developer on other developers in the team. There are various client applications such as task prioritization, early conflict detection, and providing advice on testing that can benefit from such a characterization. The DeCAF framework leverages information from the development context to bound the iDiSE change impact analysis technique to analyze only the parts of the code base that are of interest. Bounding the analysis can enable DeCAF to efficiently compute the impact of changes using a combination of program dependence and symbolic execution based approaches.

LSA: Low-cost Solar Array project

NASA Technical Reports Server (NTRS)

1978-01-01

Topics discussed include silicon material processing; large-area silicon sheet development; encapsulation materials testing and development; project engineering and operations activities, and manufacturing techniques. The steps taken to integrate these efforts, are described.

An Axial-Torsional, Thermomechanical Fatigue Testing Technique

NASA Technical Reports Server (NTRS)

Kalluri, Sreeramesh; Bonacuse, Peter J.

1995-01-01

A technique for conducting strain-controlled, thermomechanical, axial-torsional fatigue tests on thin-walled tubular specimens was developed. Three waveforms of loading, namely, the axial strain waveform, the engineering shear strain waveform, and the temperature waveform were required in these tests. The phasing relationships between the mechanical strain waveforms and the temperature and axial strain waveforms were used to define a set of four axial-torsional, thermomechanical fatigue (AT-TMF) tests. Real-time test control (3 channels) and data acquisition (a minimum of 7 channels) were performed with a software program written in C language and executed on a personal computer. The AT-TMF testing technique was used to investigate the axial-torsional thermomechanical fatigue behavior of a cobalt-base superalloy, Haynes 188. The maximum and minimum temperatures selected for the AT-TMF tests were 760 and 316 C, respectively. Details of the testing system, calibration of the dynamic temperature profile of the thin-walled tubular specimen, thermal strain compensation technique, and test control and data acquisition schemes, are reported. The isothermal, axial, torsional, and in- and out-of-phase axial-torsional fatigue behaviors of Haynes 188 at 316 and 760 C were characterized in previous investigations. The cyclic deformation and fatigue behaviors of Haynes 188 in AT-TMF tests are compared to the previously reported isothermal axial-torsional behavior of this superalloy at the maximum and minimum temperatures.

Missile airframe simulation testbed: MANPADS (MAST-M) for test and evaluation of aircraft survivability equipment

NASA Astrophysics Data System (ADS)

Clements, Jim; Robinson, Richard; Bunt, Leslie; Robinson, Joe

2011-06-01

A number of techniques have been utilized to evaluate the performance of Aircraft Survivability Equipment (ASE) against threat Man-Portable Air Defense Systems (MANPADS). These techniques include flying actual threat MANPADS against stationary ASE with simulated aircraft signatures, testing installed ASE systems against simulated threat signatures, and laboratory hardware-in-the-loop (HWIL) testing with simulated aircraft and simulated missile signatures. All of these tests lack the realism of evaluating installed ASE against in-flight MANPADS on a terminal homing intercept path toward the actual ASE equipped aircraft. This limitation is due primarily to the current inability to perform non-destructive MANPADS/Aircraft flight testing. The U.S. Army Aviation and Missile Research and Development and Engineering Center (AMRDEC) is working to overcome this limitation with the development of a recoverable surrogate MANPADS missile system capable of engaging aircraft equipped with ASE while guaranteeing collision avoidance with the test aircraft. Under its Missile Airframe Simulation Testbed - MANPADS (MAST-M) program, the AMRDEC is developing a surrogate missile system which will utilize actual threat MANPADS seeker/guidance sections to control the flight of a surrogate missile which will perform a collision avoidance and recovery maneuver prior to intercept to insure non-destructive test and evaluation of the ASE and reuse of the MANPADS seeker/guidance section. The remainder of this paper provides an overview of this development program and intended use.

Development of a high capacity bubble domain memory element and related epitaxial garnet materials for application in spacecraft data recorders. Item 2: The optimization of material-device parameters for application in bubble domain memory elements for spacecraft data recorders

NASA Technical Reports Server (NTRS)

Besser, P. J.

1976-01-01

Bubble domain materials and devices are discussed. One of the materials development goals was a materials system suitable for operation of 16 micrometer period bubble domain devices at 150 kHz over the temperature range -10 C to +60 C. Several material compositions and hard bubble suppression techniques were characterized and the most promising candidates were evaluated in device structures. The technique of pulsed laser stroboscopic microscopy was used to characterize bubble dynamic properties and device performance at 150 kHz. Techniques for large area LPE film growth were developed as a separate task. Device studies included detector optimization, passive replicator design and test and on-chip bridge evaluation. As a technology demonstration an 8 chip memory cell was designed, tested and delivered. The memory elements used in the cell were 10 kilobit serial registers.

Reduced-Order Modeling and Wavelet Analysis of Turbofan Engine Structural Response Due to Foreign Object Damage (FOD) Events

NASA Technical Reports Server (NTRS)

Turso, James; Lawrence, Charles; Litt, Jonathan

2004-01-01

The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermal/health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbofan structural model (ROM) was synthesized from a finite element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature.

Reduced-Order Modeling and Wavelet Analysis of Turbofan Engine Structural Response Due to Foreign Object Damage "FOD" Events

NASA Technical Reports Server (NTRS)

Turso, James A.; Lawrence, Charles; Litt, Jonathan S.

2007-01-01

The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermal/ health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbofan structural model (ROM) was synthesized from a finite-element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature.

Surface temperature/heat transfer measurement using a quantitative phosphor thermography system

NASA Technical Reports Server (NTRS)

Buck, G. M.

1991-01-01

A relative-intensity phosphor thermography technique developed for surface heating studies in hypersonic wind tunnels is described. A direct relationship between relative emission intensity and phosphor temperature is used for quantitative surface temperature measurements in time. The technique provides global surface temperature-time histories using a 3-CCD (Charge Coupled Device) video camera and digital recording system. A current history of technique development at Langley is discussed. Latest developments include a phosphor mixture for a greater range of temperature sensitivity and use of castable ceramics for inexpensive test models. A method of calculating surface heat-transfer from thermal image data in blowdown wind tunnels is included in an appendix, with an analysis of material thermal heat-transfer properties. Results from tests in the Langley 31-Inch Mach 10 Tunnel are presented for a ceramic orbiter configuration and a four-inch diameter hemisphere model. Data include windward heating for bow-shock/wing-shock interactions on the orbiter wing surface, and a comparison with prediction for hemisphere heating distribution.

Amorphous-silicon module hot-spot testing

NASA Technical Reports Server (NTRS)

Gonzalez, C. C.

1985-01-01

Hot spot heating occurs when cell short-circuit current is lower than string operating current. Amorphous cell hot spot are tested to develop the techniques required for performing reverse bias testing of amorphous cells. Also, to quantify the response of amorphous cells to reverse biasing. Guidelines are developed from testing for reducing hot spot susceptibility of amorphous modules and to develop a qualification test for hot spot testing of amorphous modules. It is concluded that amorphous cells undergo hot spot heating similarly to crystalline cells. Comparison of results obtained with submodules versus actual modules indicate heating levels lower in actual modules. Module design must address hot spot testing and hot spot qualification test conducted on modules showed no instabilities and minor cell erosion.

An approach to operating system testing

NASA Technical Reports Server (NTRS)

Sum, R. N., Jr.; Campbell, R. H.; Kubitz, W. J.

1984-01-01

To ensure the reliability and performance of a new system, it must be verified or validated in some manner. Currently, testing is the only resonable technique available for doing this. Part of this testing process is the high level system test. System testing is considered with respect to operating systems and in particular UNIX. This consideration results in the development and presentation of a good method for performing the system test. The method includes derivations from the system specifications and ideas for management of the system testing project. Results of applying the method to the IBM System/9000 XENIX operating system test and the development of a UNIX test suite are presented.

Compaction behavior of surrogate degraded emplaced WIPP waste.

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

Broome, Scott Thomas; Bronowski, David R.; Kuthakun, Souvanny James

The present study results are focused on laboratory testing of surrogate waste materials. The surrogate wastes correspond to a conservative estimate of degraded Waste Isolation Pilot Plant (WIPP) containers and TRU waste materials at the end of the 10,000 year regulatory period. Testing consists of hydrostatic, triaxial, and uniaxial strain tests performed on surrogate waste recipes that were previously developed by Hansen et al. (1997). These recipes can be divided into materials that simulate 50% and 100% degraded waste by weight. The percent degradation indicates the anticipated amount of iron corrosion, as well as the decomposition of cellulosics, plastics, andmore » rubbers (CPR). Axial, lateral, and volumetric strain and axial, lateral, and pore stress measurements were made. Two unique testing techniques were developed during the course of the experimental program. The first involves the use of dilatometry to measure sample volumetric strain under a hydrostatic condition. Bulk moduli of the samples measured using this technique were consistent with those measured using more conventional methods. The second technique involved performing triaxial tests under lateral strain control. By limiting the lateral strain to zero by controlling the applied confining pressure while loading the specimen axially in compression, one can maintain a right-circular cylindrical geometry even under large deformations. This technique is preferred over standard triaxial testing methods which result in inhomogeneous deformation or (3z(Bbarreling(3y. (BManifestations of the inhomogeneous deformation included non-uniform stress states, as well as unrealistic Poissons ratios (> 0.5) or those that vary significantly along the length of the specimen. Zero lateral strain controlled tests yield a more uniform stress state, and admissible and uniform values of Poissons ratio.« less

The HB-2D Polarized Neutron Development Beamline at the High Flux Isotope Reactor

NASA Astrophysics Data System (ADS)

Crow, Lowell; Hamilton, WA; Zhao, JK; Robertson, JL

2016-09-01

The Polarized Neutron Development beamline, recently commissioned at the HB-2D position on the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, provides a tool for development and testing of polarizers, polarized neutron devices, and prototyping of polarized neutron techniques. With available monochromators including pyrolytic graphite and polarizing enriched Fe-57 (Si), the instrument has operated at 4.25 and 2.6 Å wavelengths, using crystal, supermirror, or He-3 polarizers and analyzers in various configurations. The Neutron Optics and Development Team has used the beamline for testing of He-3 polarizers for use at other HFIR and Spallation Neutron Source (SNS) instruments, as well as a variety of flipper devices. Recently, we have acquired new supermirror polarizers which have improved the instrument performance. The team and collaborators also have continuing demonstration experiments of spin-echo focusing techniques, and plans to conduct polarized diffraction measurements. The beamline is also used to support a growing use of polarization techniques at present and future instruments at SNS and HFIR.

Systems design study of the Pioneer Venus spacecraft. Volume 2. Preliminary program development plan

NASA Technical Reports Server (NTRS)

1973-01-01

The preliminary development plan for the Pioneer Venus program is presented. This preliminary plan treats only developmental aspects that would have a significant effect on program cost. These significant development areas were: master program schedule planning; test planning - both unit and system testing for probes/orbiter/ probe bus; ground support equipment; performance assurance; and science integration Various test planning options and test method techniques were evaluated in terms of achieving a low-cost program without degrading mission performance or system reliability. The approaches studied and the methodology of the selected approach are defined.

Development of Oxidation Resistant Coatings on GRCop-84 Substrates by Cold Spray Process

NASA Technical Reports Server (NTRS)

Karthikeyan, J.

2007-01-01

GRCop-84, a Cu-CR-Nb alloy, has been developed for rocket engine liner applications. For maximum life additional oxidation protection is required to prevent blanching. NiCrAlY was identified as a suitable coating, and efforts were initiated to develop suitable coating techniques. Cold spray is one technique under consideration. Efforts at ASB Industries to produce dense, adherent coatings are detailed. The work culminated in the production of samples for testing at NASA Glenn Research Center.

Department of the Navy Supporting Data for Fiscal Year 1983 Budget Estimates Descriptive Summaries Submitted to Congress February 1982. Research, Development, Test and Evaluation, Navy. Book 3 of 3. Tactical Programs, Intelligence & Communications, Management & Support

DTIC Science & Technology

1982-02-01

For these data elements, Initial Milestone 11 values were established as the Flanning Estimate (PE) with the Development Estimate ( DE ) to he based ...development of improved forensic collection techniques for Naval Investigative Agents on ships and overseas bases . As this is a continuing program, the above...overseas bases ), and continue development of improved forensic collection techniques for Naval Investigative Agents on ships and overseas baszs. 4. (U) FY

CHROMATOGRAPHIC TECHNIQUES IN PHARMACEUTICAL ANALYSIS IN POIAND: HISTORY AND THE PRESENCE ON THE BASIS OF PAPERS PUBLISHED IN SELECTED POLISH PHARMACEUTICAL JOURNALS IN XX CENTURY.

PubMed

Bilek, Maciej; Namieśnik, Jacek

2016-01-01

For a long time, chromatographic techniques and techniques related to them have stimulated the development of new procedures in the field of pharmaceutical analysis. The newly developed methods, characterized by improved metrological parameters, allow for more accurate testing of, among others, the composition of raw materials, intermediates and final products. The chromatographic techniques also enable studies on waste generated in research laboratories and factories producing pharmaceuticals and parapharmaceuticals. Based on the review of reports published in Polish pharmaceutical journals, we assessed the impact of chromatographic techniques on the development of pharmaceutical analysis. The first chromatographic technique used in pharmaceutical analysis was a so-called capillary analysis. It was applied in the 1930s to control the identity of pharmaceutical formulations. In the 1940s and 1950s, the chromatographic techniques were mostly a subject of review publications, while their use in experimental work was rare. Paper chromatography and thin layer chromatography were introduced in the 1960s and 1970s, respectively. These new analytical tools have contributed to the intensive development of research in the field of phytochemistry and the analysis of herbal medicines. The development of colunm chromatography-based techniques, i.e., gas chromatography and high performance liquid chromatography took place in the end of 20th century. Both aforementioned techniques were widely applied in pharmaceutical analysis, for example, to assess the stability of drugs, test for impurities and degradation products as well as in pharmacokinetics studies. The first decade of 21" century was the time of new detection methods in gas and liquid chromatography. The information sources used to write this article were Polish pharmaceutical journals, both professional and scientific, originating from the interwar and post-war period, i.e., "Kronika Farmaceutyczna", "Farmacja Współczesna", "Wiadomości Farmaceutyczne", "Acta Poloniae Pharmaceutica", "Farmacja Polska", "Dissertationes Pharmaceuticae", "Annales UMCS sectio DDD Phamacia". The number of published works using various chromatography techniques was assessed based on the content description of individual issues of the journal "Acta Poloniae Pharmaceutica".

Journal: Efficient Hydrologic Tracer-Test Design for Tracer-Mass Estimation and Sample Collection Frequency, 1 Method Development

EPA Science Inventory

Hydrological tracer testing is the most reliable diagnostic technique available for the determination of basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test design can be difficult because of a lack of prior knowl...

Real-time open-loop frequency response analysis of flight test data

NASA Technical Reports Server (NTRS)

Bosworth, J. T.; West, J. C.

1986-01-01

A technique has been developed to compare the open-loop frequency response of a flight test aircraft real time with linear analysis predictions. The result is direct feedback to the flight control systems engineer on the validity of predictions and adds confidence for proceeding with envelope expansion. Further, gain and phase margins can be tracked for trends in a manner similar to the techniques used by structural dynamics engineers in tracking structural modal damping.

Advanced Technology Airfoil Research, volume 1, part 1. [conference on development of computational codes and test facilities

NASA Technical Reports Server (NTRS)

1979-01-01

A comprehensive review of all NASA airfoil research, conducted both in-house and under grant and contract, as well as a broad spectrum of airfoil research outside of NASA is presented. Emphasis is placed on the development of computational aerodynamic codes for airfoil analysis and design, the development of experimental facilities and test techniques, and all types of airfoil applications.

Entry, Descent, and Landing Aerothermodynamics: NASA Langley Experimental Capabilities and Contributions

NASA Technical Reports Server (NTRS)

Hollis, Brian R.; Berger, Karen T.; Berry, Scott A.; Bruckmann, Gregory J.; Buck, Gregory M.; DiFulvio, Michael; Horvath, Thomas J.; Liechty, Derek S.; Merski, N. Ronald; Murphy, Kelly J.;

Temporal and modal characterization of DoD source air toxic emission factors: final report

EPA Science Inventory

This project tested three, real-/near real-time monitoring techniques to develop air toxic emission factors for Department of Defense (DoD) platform sources. These techniques included: resonance enhanced multi photon ionization time of flight mass spectrometry (REMPI-TOFMS) for o...

Softball for Boys and Girls. Skills Test Manual.

ERIC Educational Resources Information Center

Rikli, Roberta E., Ed.

The first section of this manual provides information on the history of softball and the development of testing for proficiency in the game. The tests in the manual cover batting, fielding ground balls, overhand throwing, and baserunning. Test norms are listed for males and females at each grade level. A review is included of proper techniques and…

Safe Driving Knowledge Dissemination and Testing Techniques. Volume III: Handbook. Final Report.

ERIC Educational Resources Information Center

McKnight, James; Green, Molly A.

Guidelines are presented for use by driver licensing agencies in the development of driver manuals, tests, and other means of disseminating information and testing license applicants. An introductory chapter discusses the purposes of written license tests and of drivers' manuals, focusing on the needs of groups of drivers based on kind of vehicle,…

Development testing of large volume water sprays for warm fog dispersal

NASA Technical Reports Server (NTRS)

Keller, V. W.; Anderson, B. J.; Burns, R. A.; Lala, G. G.; Meyer, M. B.; Beard, K. V.

1986-01-01

A new brute-force method of warm fog dispersal is described. The method uses large volume recycled water sprays to create curtains of falling drops through which the fog is processed by the ambient wind and spray induced air flow. Fog droplets are removed by coalescence/rainout. The efficiency of the technique depends upon the drop size spectra in the spray, the height to which the spray can be projected, the efficiency with which fog laden air is processed through the curtain of spray, and the rate at which new fog may be formed due to temperature differences between the air and spray water. Results of a field test program, implemented to develop the data base necessary to assess the proposed method, are presented. Analytical calculations based upon the field test results indicate that this proposed method of warm fog dispersal is feasible. Even more convincingly, the technique was successfully demonstrated in the one natural fog event which occurred during the test program. Energy requirements for this technique are an order of magnitude less than those to operate a thermokinetic system. An important side benefit is the considerable emergency fire extinguishing capability it provides along the runway.

Turbine blade and vane heat flux sensor development, phase 1

NASA Technical Reports Server (NTRS)

Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

1984-01-01

Heat flux sensors available for installation in the hot section airfoils of advanced aircraft gas turbine engines were developed. Two heat flux sensors were designed, fabricated, calibrated, and tested. Measurement techniques are compared in an atmospheric pressure combustor rig test. Sensors, embedded thermocouple and the Gordon gauge, were fabricated that met the geometric and fabricability requirements and could withstand the hot section environmental conditions. Calibration data indicate that these sensors yielded repeatable results and have the potential to meet the accuracy goal of measuring local heat flux to within 5%. Thermal cycle tests and thermal soak tests indicated that the sensors are capable of surviving extended periods of exposure to the environment conditions in the turbine. Problems in calibration of the sensors caused by severe non-one dimensional heat flow were encountered. Modifications to the calibration techniques are needed to minimize this problem and proof testing of the sensors in an engine is needed to verify the designs.

Turbine blade and vane heat flux sensor development, phase 1

NASA Astrophysics Data System (ADS)

Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

1984-08-01

Heat flux sensors available for installation in the hot section airfoils of advanced aircraft gas turbine engines were developed. Two heat flux sensors were designed, fabricated, calibrated, and tested. Measurement techniques are compared in an atmospheric pressure combustor rig test. Sensors, embedded thermocouple and the Gordon gauge, were fabricated that met the geometric and fabricability requirements and could withstand the hot section environmental conditions. Calibration data indicate that these sensors yielded repeatable results and have the potential to meet the accuracy goal of measuring local heat flux to within 5%. Thermal cycle tests and thermal soak tests indicated that the sensors are capable of surviving extended periods of exposure to the environment conditions in the turbine. Problems in calibration of the sensors caused by severe non-one dimensional heat flow were encountered. Modifications to the calibration techniques are needed to minimize this problem and proof testing of the sensors in an engine is needed to verify the designs.

Application of off-line image processing for optimization in chest computed radiography using a low cost system.

PubMed

Muhogora, Wilbroad E; Msaki, Peter; Padovani, Renato

2015-03-08

 The objective of this study was to improve the visibility of anatomical details by applying off-line postimage processing in chest computed radiography (CR). Four spatial domain-based external image processing techniques were developed by using MATLAB software version 7.0.0.19920 (R14) and image processing tools. The developed techniques were implemented to sample images and their visual appearances confirmed by two consultant radiologists to be clinically adequate. The techniques were then applied to 200 chest clinical images and randomized with other 100 images previously processed online. These 300 images were presented to three experienced radiologists for image quality assessment using standard quality criteria. The mean and ranges of the average scores for three radiologists were characterized for each of the developed technique and imaging system. The Mann-Whitney U-test was used to test the difference of details visibility between the images processed using each of the developed techniques and the corresponding images processed using default algorithms. The results show that the visibility of anatomical features improved significantly (0.005 ≤ p ≤ 0.02) with combinations of intensity values adjustment and/or spatial linear filtering techniques for images acquired using 60 ≤ kVp ≤ 70. However, there was no improvement for images acquired using 102 ≤ kVp ≤ 107 (0.127 ≤ p ≤ 0.48). In conclusion, the use of external image processing for optimization can be effective in chest CR, but should be implemented in consultations with the radiologists.

Application of off‐line image processing for optimization in chest computed radiography using a low cost system

PubMed Central

Msaki, Peter; Padovani, Renato

2015-01-01

The objective of this study was to improve the visibility of anatomical details by applying off‐line postimage processing in chest computed radiography (CR). Four spatial domain‐based external image processing techniques were developed by using MATLAB software version 7.0.0.19920 (R14) and image processing tools. The developed techniques were implemented to sample images and their visual appearances confirmed by two consultant radiologists to be clinically adequate. The techniques were then applied to 200 chest clinical images and randomized with other 100 images previously processed online. These 300 images were presented to three experienced radiologists for image quality assessment using standard quality criteria. The mean and ranges of the average scores for three radiologists were characterized for each of the developed technique and imaging system. The Mann‐Whitney U‐test was used to test the difference of details visibility between the images processed using each of the developed techniques and the corresponding images processed using default algorithms. The results show that the visibility of anatomical features improved significantly (0.005≤p≤0.02) with combinations of intensity values adjustment and/or spatial linear filtering techniques for images acquired using 60≤kVp≤70. However, there was no improvement for images acquired using 102≤kVp≤107 (0.127≤p≤0.48). In conclusion, the use of external image processing for optimization can be effective in chest CR, but should be implemented in consultations with the radiologists. PACS number: 87.59.−e, 87.59.−B, 87.59.−bd PMID:26103165

Evaluating Trauma Sonography for Operational Use in the Microgravity Environment

NASA Technical Reports Server (NTRS)

Kirkpatrick, Andrew W.; Jones, Jeffrey A.; Sargsyan, Ashot; Hamilton, Douglas; Melton, Shannon; Beck, George; Nicolaou, Savvas; Campbell, Mark; Dulchavsky, Scott

2007-01-01

Sonography is the only medical imaging modality aboard the ISS, and is likely to remain the leading imaging modality in future human space flight programs. While trauma sonography (TS) has been well recognized for terrestrial trauma settings, the technique had to be evaluated for suitability in space flight prior to adopting it as an operational capability. The authors found the following four-phased evaluative approach applicable to this task: 1) identifying standard or novel terrestrial techniques for potential use in space medicine; 2) developing and testing these techniques with suggested modifications on the ground (1g) either in clinical settings or in animal models, as appropriate; 3) evaluating and refining the techniques in parabolic flight (0g); and 4) validating and implementing for clinical use in space. In Phase I of the TS project, expert opinion and literature review suggested TS to be a potential screening tool for trauma in space. In Phase II, animal models were developed and tested in ground studies, and clinical studies were carried out in collaborating trauma centers. In Phase III, animal models were flight-tested in the NASA KC-135 Reduced Gravity Laboratory. Preliminary results of the first three phases demonstrated potential clinical utility of TS in microgravity. Phase IV studies have begun to address crew training issues, on-board imaging protocols, and data transfer procedures necessary to offer the modified TS technique for space use.

Validation of a new technique to detect Cryptosporidium spp. oocysts in bovine feces.

PubMed

Inácio, Sandra Valéria; Gomes, Jancarlo Ferreira; Oliveira, Bruno César Miranda; Falcão, Alexandre Xavier; Suzuki, Celso Tetsuo Nagase; Dos Santos, Bianca Martins; de Aquino, Monally Conceição Costa; de Paula Ribeiro, Rafaela Silva; de Assunção, Danilla Mendes; Casemiro, Pamella Almeida Freire; Meireles, Marcelo Vasconcelos; Bresciani, Katia Denise Saraiva

2016-11-01

Due to its important zoonotic potential, cryptosporidiosis arouses strong interest in the scientific community, because, it was initially considered a rare and opportunistic disease. The parasitological diagnosis of the causative agent of this disease, the protozoan Cryptosporidium spp., requires the use of specific techniques of concentration and permanent staining, which are laborious and costly, and are difficult to use in routine laboratory tests. In view of the above, we conducted the feasibility, development, evaluation and intralaboratory validation of a new parasitological technique for analysis in optical microscopy of Cryptosporidium spp. oocysts, called TF-Test Coccidia, using fecal samples from calves from the city of Araçatuba, São Paulo. To confirm the aforementioned parasite and prove the diagnostic efficiency of the new technique, we used two established methodologies in the scientific literature: parasite concentration by centrifugal sedimentation and negative staining with malachite green (CSN-Malachite) and Nested-PCR. We observed good effectiveness of the TF-Test Coccidia technique, being statistically equivalent to CSN-Malachite. Thus, we verified the effectiveness of the TF-Test Coccidia parasitological technique for the detection of Cryptosporidium spp. oocysts and observed good concentration and morphology of the parasite, with a low amount of debris in the fecal smear. Copyright © 2016 Elsevier B.V. All rights reserved.

NASA Perspective on Requirements for Development of Advanced Methods Predicting Unsteady Aerodynamics and Aeroelasticity

NASA Technical Reports Server (NTRS)

Schuster, David M.

2008-01-01

Over the past three years, the National Aeronautics and Space Administration (NASA) has initiated design, development, and testing of a new human-rated space exploration system under the Constellation Program. Initial designs within the Constellation Program are scheduled to replace the present Space Shuttle, which is slated for retirement within the next three years. The development of vehicles for the Constellation system has encountered several unsteady aerodynamics challenges that have bearing on more traditional unsteady aerodynamic and aeroelastic analysis. This paper focuses on the synergy between the present NASA challenges and the ongoing challenges that have historically been the subject of research and method development. There are specific similarities in the flows required to be analyzed for the space exploration problems and those required for some of the more nonlinear unsteady aerodynamic and aeroelastic problems encountered on aircraft. The aggressive schedule, significant technical challenge, and high-priority status of the exploration system development is forcing engineers to implement existing tools and techniques in a design and application environment that is significantly stretching the capability of their methods. While these methods afford the users with the ability to rapidly turn around designs and analyses, their aggressive implementation comes at a price. The relative immaturity of the techniques for specific flow problems and the inexperience with their broad application to them, particularly on manned spacecraft flight system, has resulted in the implementation of an extensive wind tunnel and flight test program to reduce uncertainty and improve the experience base in the application of these methods. This provides a unique opportunity for unsteady aerodynamics and aeroelastic method developers to test and evaluate new analysis techniques on problems with high potential for acquisition of test and even flight data against which they can be evaluated. However, researchers may be required to alter the geometries typically used in their analyses, the types of flows analyzed, and even the techniques by which computational tools are verified and validated. This paper discusses these issues and provides some perspective on the potential for new and innovative approaches to the development of methods to attack problems in nonlinear unsteady aerodynamics.

Current issues and future perspectives of gastric cancer screening

PubMed Central

Hamashima, Chisato

2014-01-01

Gastric cancer remains the second leading cause of cancer death worldwide. About half of the incidence of gastric cancer is observed in East Asian countries, which show a higher mortality than other countries. The effectiveness of 3 new gastric cancer screening techniques, namely, upper gastrointestinal endoscopy, serological testing, and “screen and treat” method were extensively reviewed. Moreover, the phases of development for cancer screening were analyzed on the basis of the biomarker development road map. Several observational studies have reported the effectiveness of endoscopic screening in reducing mortality from gastric cancer. On the other hand, serologic testing has mainly been used for targeting the high-risk group for gastric cancer. To date, the effectiveness of new techniques for gastric cancer screening has remained limited. However, endoscopic screening is presently in the last trial phase of development before their introduction to population-based screening. To effectively introduce new techniques for gastric cancer screening in a community, incidence and mortality reduction from gastric cancer must be initially and thoroughly evaluated by conducting reliable studies. In addition to effectiveness evaluation, the balance of benefits and harms must be carefully assessed before introducing these new techniques for population-based screening. PMID:25320514

The Effects of the Refugee Crisis on Age Estimation Analysis over the Past 10 Years: A 16-Country Survey

PubMed Central

Sykes, Leanne; Bhayat, Ahmed; Bernitz, Herman

2017-01-01

Dental age estimation (AE) tests are routinely done on living and deceased persons. There is anecdotal evidence suggesting an increase in age estimations due to the refugee crisis. Our aim is to determine the reasons and methods for performing dental AE tests in both living and deceased individuals. Global trends in AE over the past 10 years were also investigated. A database of all forensic laboratories was obtained and an electronic questionnaire was sent to all of them. The questionnaire was self-developed and included questions on the reasons for performing AE tests, the preferred methods used in living and deceased individuals, and the people/organizations who requested these AE tests. The number of tests performed annually varied between 0 and 500 and the majority were on asylum seekers, refugees, and for adoption cases. Most units used multiple techniques to determine the age among the living, but seldom used more than three techniques for the deceased. The majority of tests were requested by coroners and the legal fraternity. There has been an increase in the number of dental AEs carried out and this has been mostly due to asylum seekers and refugees. The most common techniques for the living were variations of Demirjian’s technique while country specific techniques were used for the deceased. PMID:28608845

Veterinary extension on sampling techniques related to heartwater research.

PubMed

Steyn, H C; McCrindle, C M E; Du Toit, D

2010-09-01

Heartwater, a tick-borne disease caused by Ehrlichia ruminantium, is considered to be a significant cause of mortality amongst domestic and wild ruminants in South Africa. The main vector is Amblyomma hebraeum and although previous epidemiological studies have outlined endemic areas based on mortalities, these have been limited by diagnostic methods which relied mainly on positive brain smears. The indirect fluorescent antibody test (IFA) has a low specificity for heartwater organisms as it cross-reacts with some other species. Since the advent of biotechnology and genomics, molecular epidemiology has evolved using the methodology of traditional epidemiology coupled with the new molecular techniques. A new quantitative real-time polymerase chain reaction (qPCR) test has been developed for rapid and accurate diagnosis of heartwater in the live animal. This method can also be used to survey populations of A. hebraeum ticks for heartwater. Sampling whole blood and ticks for this qPCR differs from routine serum sampling, which is used for many serological tests. Veterinary field staff, particularly animal health technicians, are involved in surveillance and monitoring of controlled and other diseases of animals in South Africa. However, it was found that the sampling of whole blood was not done correctly, probably because it is a new sampling technique specific for new technology, where the heartwater organism is much more labile than the serum antibodies required for other tests. This qPCR technique is highly sensitive and can diagnose heartwater in the living animal within 2 hours, in time to treat it. Poor sampling techniques that decrease the sensitivity of the test will, however, result in a false negative diagnosis. This paper describes the development of a skills training programme for para-veterinary field staff, to facilitate research into the molecular epidemiology of heartwater in ruminants and eliminate any sampling bias due to collection errors. Humane handling techniques were also included in the training, in line with the current focus on improved livestock welfare.

Hermetic edge sealing of photovoltaic modules

NASA Astrophysics Data System (ADS)

1983-02-01

The edge sealing technique is accomplished by a combination of a chemical bond between glass and aluminum, formed by electrostatic bonding, and a metallurgical bond between aluminum and aluminum, formed by ultrasonic welding. Such a glass to metal seal promises to provide a low cost, long lifetime, highly effective hermetic seal which can protect module components from severe environments. Development of the sealing techniques and demonstration of their effectiveness by fabricating a small number of dummy modules, up to eight inches square in size, and testing them for hermeticity using helium leak testing methods are reviewed. Non-destructive test methods are investigated.

Hermetic edge sealing of photovoltaic modules

NASA Technical Reports Server (NTRS)

1983-01-01

The edge sealing technique is accomplished by a combination of a chemical bond between glass and aluminum, formed by electrostatic bonding, and a metallurgical bond between aluminum and aluminum, formed by ultrasonic welding. Such a glass to metal seal promises to provide a low cost, long lifetime, highly effective hermetic seal which can protect module components from severe environments. Development of the sealing techniques and demonstration of their effectiveness by fabricating a small number of dummy modules, up to eight inches square in size, and testing them for hermeticity using helium leak testing methods are reviewed. Non-destructive test methods are investigated.

Digital signal conditioning for flight test instrumentation

NASA Technical Reports Server (NTRS)

Bever, Glenn A.

1991-01-01

An introduction to digital measurement processes on aircraft is provided. Flight test instrumentation systems are rapidly evolving from analog-intensive to digital intensive systems, including the use of onboard digital computers. The topics include measurements that are digital in origin, as well as sampling, encoding, transmitting, and storing data. Particular emphasis is placed on modern avionic data bus architectures and what to be aware of when extracting data from them. Examples of data extraction techniques are given. Tradeoffs between digital logic families, trends in digital development, and design testing techniques are discussed. An introduction to digital filtering is also covered.

Development of an indirect immunofluorescence technique for the diagnosis of toxoplasmosis in bottlenose dolphins.

PubMed

Bernal-Guadarrama, María José; Salichs, Joan; Almunia, Javier; García-Parraga, Daniel; Fernández-Gallardo, Nuhacet; Santana-Morales, María Ángeles; Pacheco, Víctor; Afonso-Lehmann, Raquel N; Déniz, Daniel; Lorenzo-Morales, Jacob; Valladares, Basilio; Martínez-Carretero, Enrique

2014-02-01

The diagnosis of toxoplasmosis is often complicated by the lack of specific clinical symptoms or postmortem features, in humans and other animals. The only diagnostic test described so far for the serological diagnosis of Toxoplasma gondii in marine mammals is the modified agglutination test (Dubey et al., Am J Vet Res 48(8):1239-1243, 1987). The development of more sensible and specific immunological techniques requires specific antibodies, which are currently unavailable in the scientific market. Indirect immunofluorescence (IIF) is one of the most widely used methods for the diagnosis of toxoplasmosis in humans (Auer et al., Parasitol Res 12:965-970, 2000). In order to develop and apply this technique to the bottlenose dolphin (Tursiops truncatus), immunoglobulins were firstly purified using ion-exchange chromatography. The purified immunoglobulins were then injected in New Zealand rabbits in order to obtain polyclonal antibodies. These antisera were validated by the IIF technique, using as controls serum samples of dolphins infected by Toxoplasma. The results were visualized using antirabbit IgG labeled with fluorescein. This newly developed and specific serological assay was then tested with the dolphin collection of Loro Parque, Tenerife, Spain (group I), and L'Oceanogràfic of Valencia, Spain (group II). The obtained results in this study showed that none of the dolphins from group 1 were infected by T. gondii and two animals were positive in group 2. Furthermore, we conclude that this study has produced antibodies with high specificity against dolphin immunoglobulins and an IIF method which may be used as immunological diagnostic tools, especially for the serological diagnosis of toxoplasmosis.

A Real-Time Earthquake Precursor Detection Technique Using TEC from a GPS Network

NASA Astrophysics Data System (ADS)

Alp Akyol, Ali; Arikan, Feza; Arikan, Orhan

2016-07-01

Anomalies have been observed in the ionospheric electron density distribution prior to strong earthquakes. However, most of the reported results are obtained by earthquake analysis. Therefore, their implementation in practice is highly problematic. Recently, a novel earthquake precursor detection technique based on spatio-temporal analysis of Total Electron Content (TEC) data obtained from Turkish National Permanent GPS Network (TNPGN) is developed by IONOLAB group (www.ionolab.org). In the present study, the developed detection technique is implemented in a causal setup over the available data set in test phase that enables the real time implementation. The performance of the developed earthquake prediction technique is evaluated by using 10 fold cross validation over the data obtained in 2011. Among the 23 earthquakes that have magnitudes higher than 5, the developed technique can detect precursors of 14 earthquakes while producing 8 false alarms. This study is supported by TUBITAK 115E915 and Joint TUBITAK 114E092 and AS CR 14/001 projects.

Operational flow visualization techniques in the Langley Unitary Plan Wind Tunnel

NASA Technical Reports Server (NTRS)

Corlett, W. A.

1982-01-01

The unitary plan wind tunnel (UPWT) uses in daily operation are shown. New ideas for improving the quality of established flow visualization methods are developed and programs on promising new flow visualization techniques are pursued. The unitary plan wind tunnel is a supersonic facility, referred to as a production facility, although the majority of tests are inhouse basic research investigations. The facility has two 4 ft. by 4 ft. test sections which span a Mach range from 1.5 to 4.6. The cost of operation is about $10 per minute. Problems are the time required for a flow visualization test setup and investigation costs and the ability to obtain consistently repeatable results. Examples of sublimation, vapor screen, oil flow, minitufts, schlieren, and shadowgraphs taken in UPWT are presented. All tests in UPWT employ one or more of the flow visualization techniques.

Wire Crimp Connectors Verification using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2007-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp connections is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp connector and wire is shown to correlate with the results of a destructive pull test, which previously has been used to assess crimp wire junction quality. Various crimp junction pathologies (missing wire strands, incorrect wire gauge, incomplete wire insertion in connector) are ultrasonically tested, and their results are correlated with pull tests. Results show that the ultrasonic measurement technique consistently (as evidenced with pull-testing data) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying the technique while wire crimps are installed is also presented.

HIFIRE Flight 2 Overview and Status Update 2011

NASA Technical Reports Server (NTRS)

Jackson, Kevin R.; Gruber, Mark R.; Buccellato, Salvatore

2011-01-01

A collaborative international effort, the Hypersonic International Flight Research Experimentation (HIFiRE) Program aims to study basic hypersonic phenomena through flight experimentation. HIFiRE Flight 2 teams the United States Air Force Research Lab (AFRL), NASA, and the Australian Defence Science and Technology Organisation (DSTO). Flight 2 will develop an alternative test technique for acquiring high enthalpy scramjet flight test data, allowing exploration of accelerating hydrocarbon-fueled scramjet performance and dual-to-scram mode transition up to and beyond Mach 8 flight. The generic scramjet flowpath is research quality and the test fuel is a simple surrogate for an endothermically cracked liquid hydrocarbon fuel. HIFiRE Flight 2 will be a first of its kind in contribution to scramjets. The HIFiRE program builds upon the HyShot and HYCAUSE programs and aims to leverage the low-cost flight test technique developed in those programs. It will explore suppressed trajectories of a sounding rocket propelled test article and their utility in studying ramjet-scramjet mode transition and flame extinction limits research. This paper describes the overall scramjet flight test experiment mission goals and objectives, flight test approach and strategy, ground test and analysis summary, development status and project schedule. A successful launch and operation will present to the scramjet community valuable flight test data in addition to a new tool, and vehicle, with which to explore high enthalpy scramjet technologies.

Human papilloma virus testing in oropharyngeal squamous cell carcinoma: what the clinician should know.

PubMed

Mirghani, Haïtham; Amen, Furrat; Moreau, Frederique; Guigay, Joel; Ferchiou, Malek; Melkane, Antoine E; Hartl, Dana M; Lacau St Guily, Jean

2014-01-01

High risk Human Papilloma virus (HR-HPV) associated oropharyngeal cancers are on the increase. Although, the scientific community is aware of the importance of Human Papilloma Virus (HPV) testing, there is no consensus on the assays that are required to reliably identify HR-HPV related tumors. A wide range of methods have been developed. The most widely used techniques include viral DNA detection, with polymerase chain reaction (PCR) or In Situ Hybridization, and p16 detected by immunohistochemistry. However, these tests provide different information and have their own specific limitations. In this review, we summarize these different techniques, in light of the recent literature. p16 Overexpression, which is an indirect marker of HPV infection, is considered by many head and neck oncologists to be the most important marker for patient stratification. We describe the frequent lack of concordance of this marker with other assays and the possible reasons for this. The latest developments in HPV testing are also reported, such as the RNAscope™ HPV test, and how they fit into the existing framework of techniques. HPV testing must not be considered in isolation, as there are important interactions with other parameters, such as tobacco exposure. This is an important and rapidly evolving field and is likely to become pivotal to staging and choice of treatment of oropharyngeal carcinoma in the future. Copyright © 2013 Elsevier Ltd. All rights reserved.

Flight Test Results of a GPS-Based Pitot-Static Calibration Method Using Output-Error Optimization for a Light Twin-Engine Airplane

NASA Technical Reports Server (NTRS)

Martos, Borja; Kiszely, Paul; Foster, John V.

2011-01-01

As part of the NASA Aviation Safety Program (AvSP), a novel pitot-static calibration method was developed to allow rapid in-flight calibration for subscale aircraft while flying within confined test areas. This approach uses Global Positioning System (GPS) technology coupled with modern system identification methods that rapidly computes optimal pressure error models over a range of airspeed with defined confidence bounds. This method has been demonstrated in subscale flight tests and has shown small 2- error bounds with significant reduction in test time compared to other methods. The current research was motivated by the desire to further evaluate and develop this method for full-scale aircraft. A goal of this research was to develop an accurate calibration method that enables reductions in test equipment and flight time, thus reducing costs. The approach involved analysis of data acquisition requirements, development of efficient flight patterns, and analysis of pressure error models based on system identification methods. Flight tests were conducted at The University of Tennessee Space Institute (UTSI) utilizing an instrumented Piper Navajo research aircraft. In addition, the UTSI engineering flight simulator was used to investigate test maneuver requirements and handling qualities issues associated with this technique. This paper provides a summary of piloted simulation and flight test results that illustrates the performance and capabilities of the NASA calibration method. Discussion of maneuver requirements and data analysis methods is included as well as recommendations for piloting technique.

Improving the performance of streamflow forecasting model using data-preprocessing technique in Dungun River Basin

NASA Astrophysics Data System (ADS)

Khai Tiu, Ervin Shan; Huang, Yuk Feng; Ling, Lloyd

2018-03-01

An accurate streamflow forecasting model is important for the development of flood mitigation plan as to ensure sustainable development for a river basin. This study adopted Variational Mode Decomposition (VMD) data-preprocessing technique to process and denoise the rainfall data before putting into the Support Vector Machine (SVM) streamflow forecasting model in order to improve the performance of the selected model. Rainfall data and river water level data for the period of 1996-2016 were used for this purpose. Homogeneity tests (Standard Normal Homogeneity Test, the Buishand Range Test, the Pettitt Test and the Von Neumann Ratio Test) and normality tests (Shapiro-Wilk Test, Anderson-Darling Test, Lilliefors Test and Jarque-Bera Test) had been carried out on the rainfall series. Homogenous and non-normally distributed data were found in all the stations, respectively. From the recorded rainfall data, it was observed that Dungun River Basin possessed higher monthly rainfall from November to February, which was during the Northeast Monsoon. Thus, the monthly and seasonal rainfall series of this monsoon would be the main focus for this research as floods usually happen during the Northeast Monsoon period. The predicted water levels from SVM model were assessed with the observed water level using non-parametric statistical tests (Biased Method, Kendall's Tau B Test and Spearman's Rho Test).

Acoustic method of damage sensing in composite materials

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Walker, James; Lansing, Matthew

1994-01-01

The use of acoustic emission and acousto-ultrasonics to characterize impact damage in composite structures is being performed on both graphite epoxy and kevlar bottles. Further development of the acoustic emission methodology to include neural net analysis and/or other multivariate techniques will enhance the capability of the technique to identify failure mechanisms during fracture. The acousto-ultrasonics technique will be investigated to determine its ability to predict regions prone to failure prior to the burst tests. The combination of the two methods will allow for simple nondestructive tests to be capable of predicting the performance of a composite structure prior to being placed in service and during service.

Feasibility of line-ratio spectroscopy on helium and neon as edge diagnostic tool for Wendelstein 7-X

DOE PAGES

Barbui, T.; Krychowiak, M.; König, R.; ...

2016-09-27

A beam emission spectroscopy system on thermal helium (He) and neon (Ne) has been set up at Wendelstein 7-X to measure edge electron temperature and density profiles utilizing the line-ratio technique or its extension by the analysis of absolutely calibrated line emissions. The setup for a first systematic test of these techniques of quantitative atomic spectroscopy in the limiter startup phase (OP1.1) is reported together with first measured profiles. Lastly, this setup and the first results are an important test for developing the technique for the upcoming high density, low temperature island divertor regime.

Application of a transverse phase-space measurement technique for high-brightness, H{sup {minus}} beams to the GTA H{sup {minus}} beam

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

Johnson, K.F.; Garcia, R.C.; Rusthoi, D.P.

1995-05-01

The Ground Test Accelerator (GTA) had the objective Of Producing a high-brightness, high-current H-beam. The major components were a 35 keV injector, a Radio Frequency Quadrupole (RFQ), an intertank matching section (IMS), and a drift tube linac (DTL), consisting of 10 modules. A technique for measuring the transverse phase-space of high-power density beams has been developed and tested. This diagnostic has been applied to the GTA H-beam. Experimental results are compared to the slit and collector technique for transverse phase-space measurements and to simulations.

Development of Techniques for Spent Fuel Assay – Differential Dieaway Final Report

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

Swinhoe, Martyn Thomas; Goodsell, Alison; Ianakiev, Kiril Dimitrov

This report summarizes the work done under a DNDO R&D funded project on the development of the differential dieaway method to measure plutonium in spent fuel. There are large amounts of plutonium that are contained in spent fuel assemblies, and currently there is no way to make quantitative non-destructive assay. This has led NA24 under the Next Generation Safeguards Initiative (NGSI) to establish a multi-year program to investigate, develop and implement measurement techniques for spent fuel. The techniques which are being experimentally tested by the existing NGSI project do not include any pulsed neutron active techniques. The present work coversmore » the active neutron differential dieaway technique and has advanced the state of knowledge of this technique as well as produced a design for a practical active neutron interrogation instrument for spent fuel. Monte Carlo results from the NGSI effort show that much higher accuracy (1-2%) for the Pu content in spent fuel assemblies can be obtained with active neutron interrogation techniques than passive techniques, and this would allow their use for nuclear material accountancy independently of any information from the operator. The main purpose of this work was to develop an active neutron interrogation technique for spent nuclear fuel.« less

An Experimental Study of Turbulent Skin Friction Reduction in Supersonic Flow Using a Microblowing Technique

NASA Technical Reports Server (NTRS)

Hwang, Danny P.

1999-01-01

A new turbulent skin friction reduction technology, called the microblowing technique has been tested in supersonic flow (Mach number of 1.9) on specially designed porous plates with microholes. The skin friction was measured directly by a force balance and the boundary layer development was measured by a total pressure rake at the tailing edge of a test plate. The free stream Reynolds number was 1.0(10 exp 6) per meter. The turbulent skin friction coefficient ratios (C(sub f)/C(sub f0)) of seven porous plates are given in this report. Test results showed that the microblowing technique could reduce the turbulent skin friction in supersonic flow (up to 90 percent below a solid flat plate value, which was even greater than in subsonic flow).

Development and test fuel cell powered on-site integrated total energy systems. Phase 3: Full-scale power plant development

NASA Technical Reports Server (NTRS)

Kaufman, A.

1982-01-01

The on-site system application analysis is summarized. Preparations were completed for the first test of a full-sized single cell. Emphasis of the methanol fuel processor development program shifted toward the use of commercial shell-and-tube heat exchangers. An improved method for predicting the carbon-monoxide tolerance of anode catalysts is described. Other stack support areas reported include improved ABA bipolar plate bonding technology, improved electrical measurement techniques for specification-testing of stack components, and anodic corrosion behavior of carbon materials.

The space shuttle ascent vehicle aerodynamic challenges configuration design and data base development

NASA Technical Reports Server (NTRS)

Dill, C. C.; Young, J. C.; Roberts, B. B.; Craig, M. K.; Hamilton, J. T.; Boyle, W. W.

1985-01-01

The phase B Space Shuttle systems definition studies resulted in a generic configuration consisting of a delta wing orbiter, and two solid rocket boosters (SRB) attached to an external fuel tank (ET). The initial challenge facing the aerodynamic community was aerodynamically optimizing, within limits, this configuration. As the Shuttle program developed and the sensitivities of the vehicle to aerodynamics were better understood the requirements of the aerodynamic data base grew. Adequately characterizing the vehicle to support the various design studies exploded the size of the data base to proportions that created a data modeling/management challenge for the aerodynamicist. The ascent aerodynamic data base originated primarily from wind tunnel test results. The complexity of the configuration rendered conventional analytic methods of little use. Initial wind tunnel tests provided results which included undesirable effects from model support tructure, inadequate element proximity, and inadequate plume simulation. The challenge to improve the quality of test results by determining the extent of these undesirable effects and subsequently develop testing techniques to eliminate them was imposed on the aerodynamic community. The challenges to the ascent aerodynamics community documented are unique due to the aerodynamic complexity of the Shuttle launch. Never before was such a complex vehicle aerodynamically characterized. The challenges were met with innovative engineering analyses/methodology development and wind tunnel testing techniques.

Development of a special-purpose test surface guided by uncertainty analysis - Introduction of a new uncertainty analysis step

NASA Technical Reports Server (NTRS)

Wang, T.; Simon, T. W.

1988-01-01

Development of a recent experimental program to investigate the effects of streamwise curvature on boundary layer transition required making a bendable, heated and instrumented test wall, a rather nonconventional surface. The present paper describes this surface, the design choices made in its development and how uncertainty analysis was used, beginning early in the test program, to make such design choices. Published uncertainty analysis techniques were found to be of great value; but, it became clear that another step, one herein called the pre-test analysis, would aid the program development. Finally, it is shown how the uncertainty analysis was used to determine whether the test surface was qualified for service.

Silt fences: An economical technique for measuring hillslope soil erosion

Treesearch

Peter R. Robichaud; Robert E. Brown

2002-01-01

Measuring hillslope erosion has historically been a costly, time-consuming practice. An easy to install low-cost technique using silt fences (geotextile fabric) and tipping bucket rain gauges to measure onsite hillslope erosion was developed and tested. Equipment requirements, installation procedures, statistical design, and analysis methods for measuring hillslope...

Using Reflection Documents to Assess Student Learning

ERIC Educational Resources Information Center

Powell, Larkin A.

2009-01-01

Traditional assessment methods such as tests and essays may not be adequate to evaluate students' ability to solve problems and think critically. I developed a qualitative assessment technique for a junior-level Wildlife Management Techniques course that incorporated written responses in a pre- and post-course reflection exercise. I provided the…

Exploring Ways to Improve DTAG Deployment Success Rates with the ARTS Pneumatic Launcher

DTIC Science & Technology

2011-09-30

spring, four springs, no spring), and a different shock absorber system has been developed, (the giraffe leg technique or GL, Figure 2), which has...GL ( giraffe leg technique) with 3 studs (right) WORK COMPLETED During the testing period various dummy whale targets were constructed for

Teaching Writing and Critical Thinking in Large Political Science Classes

ERIC Educational Resources Information Center

Franklin, Daniel; Weinberg, Joseph; Reifler, Jason

2014-01-01

In the interest of developing a combination of teaching techniques designed to maximize efficiency "and" quality of instruction, we have experimentally tested three separate and relatively common teaching techniques in three large introductory political science classes at a large urban public university. Our results indicate that the…

Space station integrated wall design and penetration damage control

NASA Technical Reports Server (NTRS)

Coronado, A. R.; Gibbins, M. N.; Wright, M. A.; Stern, P. H.

1987-01-01

A methodology was developed to allow a designer to optimize the pressure wall, insulation, and meteoroid/debris shield system of a manned spacecraft for a given spacecraft configuration and threat environment. The threat environment consists of meteoroids and orbital debris, as specified for an arbitrary orbit and expected lifetime. An overall probability of no penetration is calculated, as well as contours of equal threat that take into account spacecraft geometry and orientation. Techniques, tools, and procedures for repairing an impacted and penetrated pressure wall were developed and tested. These techniques are applied from the spacecraft interior and account for the possibility of performing the repair in a vacuum. Hypervelocity impact testing was conducted to: (1) develop and refine appropriate penetration functions, and (2) determine the internal effects of a penetration on personnel and equipment.

Nondestructive testing for assessing wood members in structures : a review

Treesearch

R. J. Ross; R. F. Pellerin

1994-01-01

Numerous organizations have conducted research to develop nondestructive testing (NDT) techniques for assessing the condition of wood members in structures. A review of this research was published in 1991. This is an update of the 1991 report. It presents a comprehensive review of published research on the development and use of NDT tools for in-place assessment of...

Development of references of anomalies detection on P91 material using Self-Magnetic Leakage Field (SMLF) technique

NASA Astrophysics Data System (ADS)

Husin, Shuib; Afiq Pauzi, Ahmad; Yunus, Salmi Mohd; Ghafar, Mohd Hafiz Abdul; Adilin Sekari, Saiful

2017-10-01

This technical paper demonstrates the successful of the application of self-magnetic leakage field (SMLF) technique in detecting anomalies in weldment of a thick P91 materials joint (1 inch thickness). Boiler components such as boiler tubes, stub boiler at penthouse and energy piping such as hot reheat pipe (HRP) and H-balance energy piping to turbine are made of P91 material. P91 is ferromagnetic material, therefore the technique of self-magnetic leakage field (SMLF) is applicable for P91 in detecting anomalies within material (internal defects). The technique is categorized under non-destructive technique (NDT). It is the second passive method after acoustic emission (AE), at which the information on structures radiation (magnetic field and energy waves) is used. The measured magnetic leakage field of a product or component is a magnetic leakage field occurring on the component’s surface in the zone of dislocation stable slipbands under the influence of operational (in-service) or residual stresses or in zones of maximum inhomogeneity of metal structure in new products or components. Inter-granular and trans-granular cracks, inclusion, void, cavity and corrosion are considered types of inhomogeneity and discontinuity in material where obviously the output of magnetic leakage field will be shown when using this technique. The technique does not required surface preparation for the component to be inspected. This technique is contact-type inspection, which means the sensor has to touch or in-contact to the component’s surface during inspection. The results of application of SMLF technique on the developed P91 reference blocks have demonstrated that the technique is practical to be used for anomaly inspection and detection as well as identification of anomalies’ location. The evaluation of this passive self-magnetic leakage field (SMLF) technique has been verified by other conventional non-destructive tests (NDTs) on the reference blocks where simulated defects/anomalies have been developed inside at the weldment. The results from the inspection test showed that the signatures of magnetic leakage field gradient distribution prove that the peak is found on the location of defect/anomaly in the reference block. It is in agreement with the evidence of anomaly that seen in the radiography test film (RT).

X-ray digital industrial radiography (DIR) for local liquid velocity (VLL) measurement in trickle bed reactors (TBRs): Validation of the technique

NASA Astrophysics Data System (ADS)

Mohd Salleh, Khairul Anuar; Rahman, Mohd Fitri Abdul; Lee, Hyoung Koo; Al Dahhan, Muthanna H.

2014-06-01

Local liquid velocity measurements in Trickle Bed Reactors (TBRs) are one of the essential components in its hydrodynamic studies. These measurements are used to effectively determine a reactor's operating condition. This study was conducted to validate a newly developed technique that combines Digital Industrial Radiography (DIR) with Particle Tracking Velocimetry (PTV) to measure the Local Liquid Velocity (VLL) inside TBRs. Three millimeter-sized Expanded Polystyrene (EPS) beads were used as packing material. Three validation procedures were designed to test the newly developed technique. All procedures and statistical approaches provided strong evidence that the technique can be used to measure the VLL within TBRs.

X-ray digital industrial radiography (DIR) for local liquid velocity (V(LL)) measurement in trickle bed reactors (TBRs): validation of the technique.

PubMed

Mohd Salleh, Khairul Anuar; Rahman, Mohd Fitri Abdul; Lee, Hyoung Koo; Al Dahhan, Muthanna H

2014-06-01

Local liquid velocity measurements in Trickle Bed Reactors (TBRs) are one of the essential components in its hydrodynamic studies. These measurements are used to effectively determine a reactor's operating condition. This study was conducted to validate a newly developed technique that combines Digital Industrial Radiography (DIR) with Particle Tracking Velocimetry (PTV) to measure the Local Liquid Velocity (V(LL)) inside TBRs. Three millimeter-sized Expanded Polystyrene (EPS) beads were used as packing material. Three validation procedures were designed to test the newly developed technique. All procedures and statistical approaches provided strong evidence that the technique can be used to measure the V(LL) within TBRs.

Technology development of fabrication techniques for advanced solar dynamic concentrators

NASA Technical Reports Server (NTRS)

Richter, Scott W.

1991-01-01

The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

Vacuum Pyrolysis and Related ISRU Techniques

NASA Technical Reports Server (NTRS)

Cardiff, Eric H.; Pomeroy, Brian R.; Banks, Ian S.; Benz, Alexis

2007-01-01

A number of ISRU-related techniques have been developed at NASA Goddard Space Flight Center. The focus of the team has been on development of the vacuum pyrolysis technique for the production of oxygen from the lunar regolith. However, a number of related techniques have also been developed, including solar concentration, solar heating of regolith, resistive heating of regolith, sintering, regolith boiling, process modeling, parts manufacturing, and instrumentation development. An initial prototype system was developed to vaporize regolith simulants using a approx. l square meter Fresnel lens. This system was successfully used to vaporize quantities of approx. lg, and both mass spectroscopy of the gasses produced and Scanning Electron Microscopy (SEM) of the slag were done to show that oxygen was produced. Subsequent tests have demonstrated the use of a larger system With a 3.8m diameter reflective mirror to vaporize the regolith. These results and modeling of the vacuum pyrolysis reaction have indicated that the vaporization of the oxides in the regolith will occur at lower temperature for stronger vacuums. The chemical modeling was validated by testing of a resistive heating system that vaporized quantities of approx. 10g of MLS-1A. This system was also used to demonstrate the sintering of regolith simulants at reduced temperatures in high vacuum. This reduction in the required temperature prompted the development of a small-scale resistive heating system for application as a scientific instrument as well as a proof-of principle experiment for oxygen production.

An Investigation to Advance the Technology Readiness Level of the Centaur Derived On-orbit Propellant Storage and Transfer System

NASA Astrophysics Data System (ADS)

Silvernail, Nathan L.

This research was carried out in collaboration with the United Launch Alliance (ULA), to advance an innovative Centaur-based on-orbit propellant storage and transfer system that takes advantage of rotational settling to simplify Fluid Management (FM), specifically enabling settled fluid transfer between two tanks and settled pressure control. This research consists of two specific objectives: (1) technique and process validation and (2) computational model development. In order to raise the Technology Readiness Level (TRL) of this technology, the corresponding FM techniques and processes must be validated in a series of experimental tests, including: laboratory/ground testing, microgravity flight testing, suborbital flight testing, and orbital testing. Researchers from Embry-Riddle Aeronautical University (ERAU) have joined with the Massachusetts Institute of Technology (MIT) Synchronized Position Hold Engage and Reorient Experimental Satellites (SPHERES) team to develop a prototype FM system for operations aboard the International Space Station (ISS). Testing of the integrated system in a representative environment will raise the FM system to TRL 6. The tests will demonstrate the FM system and provide unique data pertaining to the vehicle's rotational dynamics while undergoing fluid transfer operations. These data sets provide insight into the behavior and physical tendencies of the on-orbit refueling system. Furthermore, they provide a baseline for comparison against the data produced by various computational models; thus verifying the accuracy of the models output and validating the modeling approach. Once these preliminary models have been validated, the parameters defined by them will provide the basis of development for accurate simulations of full scale, on-orbit systems. The completion of this project and the models being developed will accelerate the commercialization of on-orbit propellant storage and transfer technologies as well as all in-space technologies that utilize or will utilize similar FM techniques and processes.

PARTITIONING TRACERS FOR MEASURING RESIDUAL NAPL: FIELD-SCALE TEST RESULTS

EPA Science Inventory

The difficult task of locating and quantifying nonaqueous phase liquids (NAPLs) present in the vadose and saturated zones has prompted the development of innovative, nondestructive characterization techniques. The use of the interwell partitioning tracer's (IWPT) test, in which ...

Solderability test system

DOEpatents

Yost, Fred; Hosking, Floyd M.; Jellison, James L.; Short, Bruce; Giversen, Terri; Reed, Jimmy R.

1998-01-01

A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time.

A study to define an in-flight dynamics measurement and data applications program for space shuttle payloads

NASA Technical Reports Server (NTRS)

Rader, W. P.; Barrett, S.; Payne, K. R.

1975-01-01

Data measurement and interpretation techniques were defined for application to the first few space shuttle flights, so that the dynamic environment could be sufficiently well established to be used to reduce the cost of future payloads through more efficient design and environmental test techniques. It was concluded that: (1) initial payloads must be given comprehensive instrumentation coverage to obtain detailed definition of acoustics, vibration, and interface loads, (2) analytical models of selected initial payloads must be developed and verified by modal surveys and flight measurements, (3) acoustic tests should be performed on initial payloads to establish realistic test criteria for components and experiments in order to minimize unrealistic failures and retest requirements, (4) permanent data banks should be set up to establish statistical confidence in the data to be used, (5) a more unified design/test specification philosophy is needed, (6) additional work is needed to establish a practical testing technique for simulation of vehicle transients.

SIRU utilization. Volume 1: Theory, development and test evaluation

NASA Technical Reports Server (NTRS)

Musoff, H.

1974-01-01

The theory, development, and test evaluations of the Strapdown Inertial Reference Unit (SIRU) are discussed. The statistical failure detection and isolation, single position calibration, and self alignment techniques are emphasized. Circuit diagrams of the system components are provided. Mathematical models are developed to show the performance characteristics of the subsystems. Specific areas of the utilization program are identified as: (1) error source propagation characteristics and (2) local level navigation performance demonstrations.

Load Measurement in Structural Members Using Guided Acoustic Waves

NASA Astrophysics Data System (ADS)

Chen, Feng; Wilcox, Paul D.

2006-03-01

A non-destructive technique to measure load in structures such as rails and bridge cables by using guided acoustic waves is investigated both theoretically and experimentally. Robust finite element models for predicting the effect of load on guided wave propagation are developed and example results are presented for rods. Reasonably good agreement of experimental results with modelling prediction is obtained. The measurement technique has been developed to perform tests on larger specimens.

Maintaining Stability During a Conducted-Ripple EMC Test

NASA Technical Reports Server (NTRS)

Vorperian, Vatche

2007-01-01

An improved technique, and electronic circuitry to implement the technique, have been developed for a military-standard electromagnetic-compatibility (EMC) test in which one analyzes susceptibility to low-frequency ripple conducted into the equipment under test via a DC power line. In the traditional technique for performing the particular test, the ripple is coupled onto the DC power line via a transformer. Depending upon some design details of the equipment under test, the inductance of the transformer can contribute a degree of instability that results in an oscillation of amplitude large enough to destroy the equipment. It is usually possible to suppress the oscillation by connecting a damping resistor to the primary terminals of the ripple-injection transformer. However, it is important to emphasize the usually in the preceding sentence: sometimes, the resistive damping becomes insufficient to suppress destructive oscillation. In addition, undesirably, the resistor contributes to power dissipation and power demand, and thereby also necessitates the use of a larger ripple voltage amplifier. Yet another disadvantage of the transformer-coupling technique is that the transformer introduces low-frequency distortion of the injected ripple voltage. The improved technique makes it possible to inject ripple with very low distortion at low frequency, without inducing oscillation. In this technique, a transformer is not used: Instead, power is fed to the equipment under test via series power field-effect transistors (FETs) controlled by a summing operational amplifier. One of the inputs to the amplifier controls the DC component of the power-line voltage; the other input, generated by an external oscillator, controls the ripple component. The circuitry for implementing this technique includes panel displays, an internal power supply for the operational amplifier and panel displays, and amplitude controls for the DC and ripple powerline voltage components.

Computed Tomography and Thermography Increases CMC Material and Process Development Efficiency and Testing Effectiveness

NASA Technical Reports Server (NTRS)

Effinger, Michael; Beshears, Ron; Hufnagle, David; Walker, James; Russell, Sam; Stowell, Bob; Myers, David

2002-01-01

Nondestructive characterization techniques have been used to steer development and testing of CMCs. Computed tomography is used to determine the volumetric integrity of the CMC plates and components. Thermography is used to determine the near surface integrity of the CMC plates and components. For process and material development, information such as density uniformity, part delamination, and dimensional tolerance conformity is generated. The information from the thermography and computed tomography is correlated and then specimen cutting maps are superimposed on the thermography images. This enables for tighter data and potential explanation of off nominal test data. Examples of nondestructive characterization utilization to make decisions in process and material development and testing are presented.

Development of the symmetrical laser shock test for weak bond inspection.

NASA Astrophysics Data System (ADS)

Sagnard, Maxime; Berthe, Laurent; Ecault, Romain; Touchard, Fabienne; Boustie, Michel

2017-06-01

This paper presents the LAser Shock Adhesion Test (LASAT) using symmetrical laser shocks. The study is part of ComBoNDT European project that develops new Non-Destructive Tests (NDT) to assess adherence properties of bonded composite structures. This NDT technique relies on the creation of a plasma on both side of the sample using two lasers. The plasma expands and generates shockwaves inside the material. When combined, the shockwaves create a local tensile strength. Properly set, this stress can be used to test interfaces adherence. Numerous experiments have shown that this adaptive technique can discriminate a good bond from a weak one, without damaging the composite structure. Weak bonds are usually created by contaminated surfaces (residues of release agent, finger prints, ...) and were artificially recreated for ComBoNDT test samples. Numerical simulations are being developed as well, to improve the comprehension of the physical phenomenon. And ultimately, using these numerical results, one should be able to find the correct laser parameters (intensity, laser spot diameter) to generate the right tensile strength at the desired location. This project has received funding from the European Union's Horizon 2020 research and innovation program under Grant agreement N 63649.

Development of a Tomography Technique for Assessment of the Material Condition of Concrete Using Optimized Elastic Wave Parameters.

PubMed

Chai, Hwa Kian; Liu, Kit Fook; Behnia, Arash; Yoshikazu, Kobayashi; Shiotani, Tomoki

2016-04-16

Concrete is the most ubiquitous construction material. Apart from the fresh and early age properties of concrete material, its condition during the structure life span affects the overall structural performance. Therefore, development of techniques such as non-destructive testing which enable the investigation of the material condition, are in great demand. Tomography technique has become an increasingly popular non-destructive evaluation technique for civil engineers to assess the condition of concrete structures. In the present study, this technique is investigated by developing reconstruction procedures utilizing different parameters of elastic waves, namely the travel time, wave amplitude, wave frequency, and Q-value. In the development of algorithms, a ray tracing feature was adopted to take into account the actual non-linear propagation of elastic waves in concrete containing defects. Numerical simulation accompanied by experimental verifications of wave motion were conducted to obtain wave propagation profiles in concrete containing honeycomb as a defect and in assessing the tendon duct filling of pre-stressed concrete (PC) elements. The detection of defects by the developed tomography reconstruction procedures was evaluated and discussed.

Numerical Tests for the Problem of U-Pu Fuel Burnup in Fuel Rod and Polycell Models Using the MCNP Code

NASA Astrophysics Data System (ADS)

Muratov, V. G.; Lopatkin, A. V.

An important aspect in the verification of the engineering techniques used in the safety analysis of MOX-fuelled reactors, is the preparation of test calculations to determine nuclide composition variations under irradiation and analysis of burnup problem errors resulting from various factors, such as, for instance, the effect of nuclear data uncertainties on nuclide concentration calculations. So far, no universally recognized tests have been devised. A calculation technique has been developed for solving the problem using the up-to-date calculation tools and the latest versions of nuclear libraries. Initially, in 1997, a code was drawn up in an effort under ISTC Project No. 116 to calculate the burnup in one VVER-1000 fuel rod, using the MCNP Code. Later on, the authors developed a computation technique which allows calculating fuel burnup in models of a fuel rod, or a fuel assembly, or the whole reactor. It became possible to apply it to fuel burnup in all types of nuclear reactors and subcritical blankets.

Development of Semi-Span Model Test Techniques

NASA Technical Reports Server (NTRS)

Pulnam, L. Elwood (Technical Monitor); Milholen, William E., II; Chokani, Ndaona; McGhee, Robert J.

1996-01-01

A computational investigation was performed to support the development of a semi-span model test capability in the NASA Langley Research Center's National Transonic Facility. This capability is desirable for the testing of advanced subsonic transport aircraft at full-scale Reynolds numbers. A state-of-the-art three-dimensional Navier-Stokes solver was used to examine methods to improve the flow over a semi-span configuration. First, a parametric study is conducted to examine the influence of the stand-off height on the flow over the semi-span model. It is found that decreasing the stand-off height, below the maximum fuselage radius, improves the aerodynamic characteristics of the semi-span model. Next, active sidewall boundary layer control techniques are examined. Juncture region blowing jets, upstream tangential blowing, and sidewall suction are found to improve the flow over the aft portion of the semi-span model. Both upstream blowing and suction are found to reduce the sidewall boundary layer separation. The resulting near surface streamline patterns are improved, and found to be quite similar to the full-span results. Both techniques however adversely affect the pitching moment coefficient.

Development of Semi-Span Model Test Techniques

NASA Technical Reports Server (NTRS)

Milholen, William E., II; Chokani, Ndaona; McGhee, Robert J.

1996-01-01

A computational investigation was performed to support the development of a semispan model test capability in the NASA Langley Research Center's National Transonic Facility. This capability is desirable for the testing of advanced subsonic transport aircraft at full-scale Reynolds numbers. A state-of-the-art three-dimensional Navier-Stokes solver was used to examine methods to improve the flow over a semi-span configuration. First, a parametric study is conducted to examine the influence of the stand-off height on the flow over the semispan model. It is found that decreasing the stand-off height, below the maximum fuselage radius, improves the aerodynamic characteristics of the semi-span model. Next, active sidewall boundary layer control techniques are examined. Juncture region blowing jets, upstream tangential blowing, and sidewall suction are found to improve the flow over the aft portion of the semispan model. Both upstream blowing and suction are found to reduce the sidewall boundary layer separation. The resulting near surface streamline patterns are improved, and found to be quite similar to the full-span results. Both techniques however adversely affect the pitching moment coefficient.

A simplified method for determining heat of combustion of natural gas

NASA Technical Reports Server (NTRS)

Singh, Jag J.; Chegini, Hoshang; Mall, Gerald H.

1987-01-01

A simplified technique for determination of the heat of combustion of natural gas has been developed. It is a variation of the previously developed technique wherein the carrier air, in which the test sample was burnt, was oxygen enriched to adjust the mole fraction of oxygen in the combustion product gases up to that in the carrier air. The new technique eliminates the need for oxygen enrichment of the experimental mixtures and natural gas samples and has been found to predict their heats of combustion to an uncertainty of the order of 1 percent.

Development of flight experiments for remote measurement of pollution

NASA Technical Reports Server (NTRS)

Keafer, L. S., Jr.; Kopia, L. P.

1973-01-01

The status as of February 1973 of several NASA-sponsored development projects is reported concerning flight experiments for remote measurement of pollution. Eight passive multispectral instruments for remotely sensing air and water pollutants are described, as well as two active (laser radar) measuring techniques. These techniques are expected to add some new dimensions to the remote sensing of water quality, oceanographic parameters, and earth resources. Multiple applications in these fields are generally possible. Successful completion of the flight demonstration tests and comparisons with simultaneously obtained surface truth measurements may establish these techniques as valid water quality monitoring tools.

Advanced Platform for Development and Evaluation of Grid Interconnection Systems Using Hardware-in-the-Loop (Poster)

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

Lundstrom, B.; Shirazi, M.; Coddington, M.

2013-02-01

This poster describes a Grid Interconnection System Evaluator (GISE) that leverages hardware-in-the-loop (HIL) simulation techniques to rapidly evaluate the grid interconnection standard conformance of an ICS according to the procedures in IEEE Std 1547.1TM. The architecture and test sequencing of this evaluation tool, along with a set of representative ICS test results from three different photovoltaic (PV) inverters, are presented. The GISE adds to the National Renewable Energy Laboratory's (NREL) evaluation platform that now allows for rapid development of ICS control algorithms using controller HIL (CHIL) techniques, the ability to test the dc input characteristics of PV-based ICSs through themore » use of a PV simulator capable of simulating real-world dynamics using power HIL (PHIL), and evaluation of ICS grid interconnection conformance.« less

Conducting field studies for testing pesticide leaching models

USGS Publications Warehouse

Smith, Charles N.; Parrish, Rudolph S.; Brown, David S.

1990-01-01

A variety of predictive models are being applied to evaluate the transport and transformation of pesticides in the environment. These include well known models such as the Pesticide Root Zone Model (PRZM), the Risk of Unsaturated-Saturated Transport and Transformation Interactions for Chemical Concentrations Model (RUSTIC) and the Groundwater Loading Effects of Agricultural Management Systems Model (GLEAMS). The potentially large impacts of using these models as tools for developing pesticide management strategies and regulatory decisions necessitates development of sound model validation protocols. This paper offers guidance on many of the theoretical and practical problems encountered in the design and implementation of field-scale model validation studies. Recommendations are provided for site selection and characterization, test compound selection, data needs, measurement techniques, statistical design considerations and sampling techniques. A strategy is provided for quantitatively testing models using field measurements.

Technique development for modulus, microcracking, hermeticity, and coating evaluation capability characterization of SiC/SiC tubes

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

Hu, Xunxiang; Ang, Caen K.; Singh, Gyanender P.

Driven by the need to enlarge the safety margins of nuclear fission reactors in accident scenarios, research and development of accident-tolerant fuel has become an important topic in the nuclear engineering and materials community. A continuous-fiber SiC/SiC composite is under consideration as a replacement for traditional zirconium alloy cladding owing to its high-temperature stability, chemical inertness, and exceptional irradiation resistance. An important task is the development of characterization techniques for SiC/SiC cladding, since traditional work using rectangular bars or disks cannot directly provide useful information on the properties of SiC/SiC composite tubes for fuel cladding applications. At Oak Ridge Nationalmore » Laboratory, experimental capabilities are under development to characterize the modulus, microcracking, and hermeticity of as-fabricated, as-irradiated SiC/SiC composite tubes. Resonant ultrasound spectroscopy has been validated as a promising technique to evaluate the elastic properties of SiC/SiC composite tubes and microcracking within the material. A similar technique, impulse excitation, is efficient in determining the basic mechanical properties of SiC bars prepared by chemical vapor deposition; it also has potential for application in studying the mechanical properties of SiC/SiC composite tubes. Complete evaluation of the quality of the developed coatings, a major mitigation strategy against gas permeation and hydrothermal corrosion, requires the deployment of various experimental techniques, such as scratch indentation, tensile pulling-off tests, and scanning electron microscopy. In addition, a comprehensive permeation test station is being established to assess the hermeticity of SiC/SiC composite tubes and to determine the H/D/He permeability of SiC/SiC composites. This report summarizes the current status of the development of these experimental capabilities.« less

Investigation of bus transit schedule behavior modeling using advanced techniques

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

Kalaputapu, R.; Demetsky, M.J.

This research focused on investigating the application of artificial neural networks (ANN) and the Box-Jenkins technique for developing and testing schedule behavior models using data obtained for a test route from Tidewater Regional Transit`s AVL system. The three ANN architectures investigated were: Feedforward Network, Elman Network and Jordan Network. In addition, five different model structures were investigated. The time-series methodology was adopted for developing the schedule behavior models. Finally, the role of a schedule behavior model within the framework of an intelligent transit management system is defined and the potential utility of the schedule behavior model is discussed using anmore » example application.« less

Development flight tests of the Viking decelerator system.

NASA Technical Reports Server (NTRS)

Murrow, H. N.; Eckstrom, C. V.; Henke, D. W.

1973-01-01

Significant aspects of a low altitude flight test phase of the overall Viking decelerator system development are given. This test series included nine aircraft drop tests that were conducted at the Joint Parachute Test Facility, El Centro, California, between September 1971 and May 1972. The test technique and analytical planning method utilized to best simulate loading conditions in a low density environment are presented and some test results are shown to assess their adequacy. Performance effects relating to suspension line lengths of 1.7 D sub o with different canopy loadings are noted. System hardware developments are described, in particular the utilization of a fabric deployment mortar cover which remained attached to the parachute canopy. Finally, the contribution of this test series to the overall program is assessed.

Virtual Diagnostic Interface: Aerospace Experimentation in the Synthetic Environment

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; McCrea, Andrew C.

2009-01-01

The Virtual Diagnostics Interface (ViDI) methodology combines two-dimensional image processing and three-dimensional computer modeling to provide comprehensive in-situ visualizations commonly utilized for in-depth planning of wind tunnel and flight testing, real time data visualization of experimental data, and unique merging of experimental and computational data sets in both real-time and post-test analysis. The preparation of such visualizations encompasses the realm of interactive three-dimensional environments, traditional and state of the art image processing techniques, database management and development of toolsets with user friendly graphical user interfaces. ViDI has been under development at the NASA Langley Research Center for over 15 years, and has a long track record of providing unique and insightful solutions to a wide variety of experimental testing techniques and validation of computational simulations. This report will address the various aspects of ViDI and how it has been applied to test programs as varied as NASCAR race car testing in NASA wind tunnels to real-time operations concerning Space Shuttle aerodynamic flight testing. In addition, future trends and applications will be outlined in the paper.

Virtual Diagnostic Interface: Aerospace Experimentation in the Synthetic Environment

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; McCrea, Andrew C.

2010-01-01

The Virtual Diagnostics Interface (ViDI) methodology combines two-dimensional image processing and three-dimensional computer modeling to provide comprehensive in-situ visualizations commonly utilized for in-depth planning of wind tunnel and flight testing, real time data visualization of experimental data, and unique merging of experimental and computational data sets in both real-time and post-test analysis. The preparation of such visualizations encompasses the realm of interactive three-dimensional environments, traditional and state of the art image processing techniques, database management and development of toolsets with user friendly graphical user interfaces. ViDI has been under development at the NASA Langley Research Center for over 15 years, and has a long track record of providing unique and insightful solutions to a wide variety of experimental testing techniques and validation of computational simulations. This report will address the various aspects of ViDI and how it has been applied to test programs as varied as NASCAR race car testing in NASA wind tunnels to real-time operations concerning Space Shuttle aerodynamic flight testing. In addition, future trends and applications will be outlined in the paper.

Development of numerical methods for overset grids with applications for the integrated Space Shuttle vehicle

NASA Technical Reports Server (NTRS)

Chan, William M.

1995-01-01

Algorithms and computer code developments were performed for the overset grid approach to solving computational fluid dynamics problems. The techniques developed are applicable to compressible Navier-Stokes flow for any general complex configurations. The computer codes developed were tested on different complex configurations with the Space Shuttle launch vehicle configuration as the primary test bed. General, efficient and user-friendly codes were produced for grid generation, flow solution and force and moment computation.

Lightning Initiation Forecasting: An Operational Dual-Polarimetric Radar Technique

NASA Technical Reports Server (NTRS)

Woodard, Crystal J.; Carey, L. D.; Petersen, W. A.; Roeder, W. P.

2011-01-01

The objective of this NASA MSFC and NOAA CSTAR funded study is to develop and test operational forecast algorithms for the prediction of lightning initiation utilizing the C-band dual-polarimetric radar, UAHuntsville's Advanced Radar for Meteorological and Operational Research (ARMOR). Although there is a rich research history of radar signatures associated with lightning initiation, few studies have utilized dual-polarimetric radar signatures (e.g., Z(sub dr) columns) and capabilities (e.g., fuzzy-logic particle identification [PID] of precipitation ice) in an operational algorithm for first flash forecasting. The specific goal of this study is to develop and test polarimetric techniques that enhance the performance of current operational radar reflectivity based first flash algorithms. Improving lightning watch and warning performance will positively impact personnel safety in both work and leisure environments. Advanced warnings can provide space shuttle launch managers time to respond appropriately to secure equipment and personnel, while they can also provide appropriate warnings for spectators and players of leisure sporting events to seek safe shelter. Through the analysis of eight case dates, consisting of 35 pulse-type thunderstorms and 20 non-thunderstorm case studies, lightning initiation forecast techniques were developed and tested. The hypothesis is that the additional dual-polarimetric information could potentially reduce false alarms while maintaining high probability of detection and increasing lead-time for the prediction of the first lightning flash relative to reflectivity-only based techniques. To test the hypothesis, various physically-based techniques using polarimetric variables and/or PID categories, which are strongly correlated to initial storm electrification (e.g., large precipitation ice production via drop freezing), were benchmarked against the operational reflectivity-only based approaches to find the best compromise between forecast skill and lead-time. Forecast skill is determined by statistical analysis of probability of detection (POD), false alarm ratio (FAR), Operational Utility Index (OUI), and critical success index (CSI).

The Detection and Influence of Problematic Item Content in Ability Tests: An Examination of Sensitivity Review Practices for Personnel Selection Test Development

ERIC Educational Resources Information Center

Grand, James A.; Golubovich, Juliya; Ryan, Ann Marie; Schmitt, Neal

2013-01-01

In organizational and educational practices, sensitivity reviews are commonly advocated techniques for reducing test bias and enhancing fairness. In the present paper, results from two studies are reported which investigate how effective individuals are at detecting problematic test content and the influence such content has on important testing…

Fractured reservoir characterization through injection, falloff, and flowback tests

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

Peng, C.P.; Singh, P.K.; Halvorsen, H.

1992-09-01

This paper presents the development of a multiphase pressure-transient-analysis technique for naturally fractured reservoirs and the analysis of a series of field tests performed to evaluate the water injection potential and the reservoir characteristics of a naturally fractured reservoir. These included step-rate, water-injectivity, pressure-falloff, and flowback tests. Through these tests, a description of the reservoir was obtained.

Development of Proposed Standards for Testing Solar Collectors and Thermal Storage Devices. NBS Technical Note 899.

ERIC Educational Resources Information Center

Hill, James E.; And Others

A study has been made at the National Bureau of Standards of the different techniques that are or could be used for testing solar collectors and thermal storage devices that are used in solar heating and cooling systems. This report reviews the various testing methods and outlines a recommended test procedure, including apparatus and…

Is the Dresden technique a mechanical design of choice suitable for the repair of middle third Achilles tendon ruptures? A biomechanical study.

PubMed

de la Fuente, C; Carreño-Zillmann, G; Marambio, H; Henríquez, H

2016-01-01

To compare the mechanical failure of the Dresden technique for Achilles tendon repair with the double modified Kessler technique controlled repair technique. The maximum resistance of the two repair techniques are also compared. A total of 30 Achilles tendon ruptures in bovine specimens were repaired with an Ethibond(®) suture to 4.5cm from the calcaneal insertion. Each rupture was randomly distributed into one of two surgical groups. After repair, each specimen was subjected to a maximum traction test. The mechanical failure (tendon, suture, or knot) rates (proportions) were compared using the exact Fisher test (α=.05), and the maximum resistances using the Student t test (α=.05). There was a difference in the proportions of mechanical failures, with the most frequent being a tendon tear in the Dresden technique, and a rupture of the suture in the Kessler technique. The repair using the Dresden technique performed in the open mode, compared to the Kessler technique, has a more suitable mechanical design for the repair of middle third Achilles tendon ruptures on developing a higher tensile resistance in 58.7%. However, its most common mechanical failure was a tendon tear, which due to inappropriate loads could lead to lengthening of the Achilles tendon. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Test-driven programming

NASA Astrophysics Data System (ADS)

Georgiev, Bozhidar; Georgieva, Adriana

2013-12-01

In this paper, are presented some possibilities concerning the implementation of a test-driven development as a programming method. Here is offered a different point of view for creation of advanced programming techniques (build tests before programming source with all necessary software tools and modules respectively). Therefore, this nontraditional approach for easier programmer's work through building tests at first is preferable way of software development. This approach allows comparatively simple programming (applied with different object-oriented programming languages as for example JAVA, XML, PYTHON etc.). It is predictable way to develop software tools and to provide help about creating better software that is also easier to maintain. Test-driven programming is able to replace more complicated casual paradigms, used by many programmers.

Wave Mode Discrimination of Coded Ultrasonic Guided Waves Using Two-Dimensional Compressed Pulse Analysis.

PubMed

Malo, Sergio; Fateri, Sina; Livadas, Makis; Mares, Cristinel; Gan, Tat-Hean

2017-07-01

Ultrasonic guided waves testing is a technique successfully used in many industrial scenarios worldwide. For many complex applications, the dispersive nature and multimode behavior of the technique still poses a challenge for correct defect detection capabilities. In order to improve the performance of the guided waves, a 2-D compressed pulse analysis is presented in this paper. This novel technique combines the use of pulse compression and dispersion compensation in order to improve the signal-to-noise ratio (SNR) and temporal-spatial resolution of the signals. The ability of the technique to discriminate different wave modes is also highlighted. In addition, an iterative algorithm is developed to identify the wave modes of interest using adaptive peak detection to enable automatic wave mode discrimination. The employed algorithm is developed in order to pave the way for further in situ applications. The performance of Barker-coded and chirp waveforms is studied in a multimodal scenario where longitudinal and flexural wave packets are superposed. The technique is tested in both synthetic and experimental conditions. The enhancements in SNR and temporal resolution are quantified as well as their ability to accurately calculate the propagation distance for different wave modes.

Reliability-based econometrics of aerospace structural systems: Design criteria and test options. Ph.D. Thesis - Georgia Inst. of Tech.

NASA Technical Reports Server (NTRS)

Thomas, J. M.; Hanagud, S.

1974-01-01

The design criteria and test options for aerospace structural reliability were investigated. A decision methodology was developed for selecting a combination of structural tests and structural design factors. The decision method involves the use of Bayesian statistics and statistical decision theory. Procedures are discussed for obtaining and updating data-based probabilistic strength distributions for aerospace structures when test information is available and for obtaining subjective distributions when data are not available. The techniques used in developing the distributions are explained.

Containment of composite fan blades

NASA Technical Reports Server (NTRS)

Stotler, C. L.; Coppa, A. P.

1979-01-01

A lightweight containment was developed for turbofan engine fan blades. Subscale ballistic-type tests were first run on a number of concepts. The most promising configuration was selected and further evaluated by larger scale tests in a rotating test rig. Weight savings made possible by the use of this new containment system were determined and extrapolated to a CF6-size engine. An analytical technique was also developed to predict the released blades motion when involved in the blade/casing interaction process. Initial checkout of this procedure was accomplished using several of the tests run during the program.

Flexible, FEP-Teflon covered solar cell module development

NASA Technical Reports Server (NTRS)

Rauschenbach, H. S.; Cannady, M. D.

1976-01-01

Techniques and equipment were developed for the large scale, low-cost fabrication of lightweight, roll-up and fold-up, FEP-Teflon encapsulated solar cell modules. Modules were fabricated by interconnecting solderless single-crystal silicon solar cells and heat laminating them at approximately 300 C between layers of optically clear FEP and to a loadbearing Kapton substrate sheet. Modules were fabricated from both conventional and wraparound contact solar cells. A heat seal technique was developed for mechanically interconnecting modules into an array. The electrical interconnections for both roll-up and fold-up arrays were also developed. The use of parallel-gap resistance welding, ultrasonic bonding, and thermocompression bonding processes for attaching interconnects to solar cells were investigated. Parallel-gap welding was found to be best suited for interconnecting the solderless solar cells into modules. Details of the fabrication equipment, fabrication processes, module and interconnect designs, environmental test equipment, and test results are presented.

Apollo telescope mount thermal systems unit thermal vacuum test

NASA Technical Reports Server (NTRS)

Trucks, H. F.; Hueter, U.; Wise, J. H.; Bachtel, F. D.

1971-01-01

The Apollo Telescope Mount's thermal systems unit was utilized to conduct a full-scale thermal vacuum test to verify the thermal design and the analytical techniques used to develop the thermal mathematical models. Thermal vacuum test philosophy, test objectives configuration, test monitoring, environment simulation, vehicle test performance, and data correlation are discussed. Emphasis is placed on planning and execution of the thermal vacuum test with particular attention on problems encountered in conducting a test of this maguitude.

Evaluation of Oil-Industry Stimulation Practices for Engineered Geothermal Systems

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

Peter Van Dyke; Leen Weijers; Ann Robertson-Tait

Geothermal energy extraction is typically achieved by use of long open-hole intervals in an attempt to connect the well with the greatest possible rock mass. This presents a problem for the development of Enhanced (Engineered) Geothermal Systems (EGS), owing to the challenge of obtaining uniform stimulation throughout the open-hole interval. Fluids are often injected in only a fraction of that interval, reducing heat transfer efficiency and increasing energy cost. Pinnacle Technologies, Inc. and GeothermEx, Inc. evaluated a variety of techniques and methods that are commonly used for hydraulic fracturing of oil and gas wells to increase and evaluate stimulation effectivenessmore » in EGS wells. Headed by Leen Weijers, formerly Manager of Technical Development at Pinnacle Technologies, Inc., the project ran from August 1, 2004 to July 31, 2006 in two one-year periods to address the following tasks and milestones: 1) Analyze stimulation results from the closest oil-field equivalents for EGS applications in the United States (e.g., the Barnett Shale in North Texas) (section 3 on page 8). Pinnacle Technologies, Inc. has collected fracture growth data from thousands of stimulations (section 3.1 on page 12). This data was further evaluated in the context of: a) Identifying techniques best suited to developing a stimulated EGS fracture network (section 3.2 on page 29), and b) quantifying the growth of the network under various conditions to develop a calibrated model for fracture network growth (section 3.3 on page 30). The developed model can be used to design optimized EGS fracture networks that maximize contact with the heat source and minimize short-circuiting (section 3.4 on page 38). 2) Evaluate methods used in oil field applications to improve fluid diversion and penetration and determine their applicability to EGS (section 4 on page 50). These methods include, but are not limited to: a) Stimulation strategies (propped fracturing versus water fracturing versus injecting fluid below fracturing gradients) (section 4.1 on page 50); b) zonal isolation methods (by use of perforated casing or packers) (section 4.2 on page 57); c) fracture re-orientation and fracture network growth techniques (e.g., by use of alternating high- and low-rate injections) (section 4.4 on page 74); and d) fluid diversion methods (by use of the SurgiFrac technique, the StimGun perforation technique, or stress shadowing). This project task is to be completed in the first project year, enabling the most promising techniques to be field tested and evaluated in the second project year. 3) Study the applicability of the methods listed above by utilizing several techniques (section 5 on page 75) including, but not limited to: a) Hydraulic Impedance Testing (HIT) to determine the location of open hydraulic fractures along a open-hole interval; b) pressure transient testing to determine reservoir permeability, pore pressure, and closure stress; and c) treatment well tilt mapping or microseismic mapping to evaluate fracture coverage. These techniques were reviewed for their potential application for EGS in the first project year (section 5.1 on page 75). This study also includes further analysis of any field testing that will be conducted in the Desert Peak area in Nevada for ORMAT Nevada, Inc. (section 5.2 on page 86), with the aim to close the loop to provide reliable calibrated fracture model results. Developed through its hydraulic fracture consulting business, techniques of Pinnacle Technologies, Inc. for stimulating and analyzing fracture growth have helped the oil and gas industry to improve hydraulic fracturing from both a technical and economic perspective. In addition to more than 30 years of experience in the development of geothermal energy for commercial power generation throughout the world, GeothermEx, Inc. brings to the project: 1) Detailed information about specific developed and potential EGS reservoirs, 2) experience with geothermal well design, completion, and testing practices, and 3) a direct connection to the Desert Peak EGS project.« less

Gearbox Tooth Cut Fault Diagnostics Using Acoustic Emission and Vibration Sensors — A Comparative Study

PubMed Central

Qu, Yongzhi; He, David; Yoon, Jae; Van Hecke, Brandon; Bechhoefer, Eric; Zhu, Junda

2014-01-01

In recent years, acoustic emission (AE) sensors and AE-based techniques have been developed and tested for gearbox fault diagnosis. In general, AE-based techniques require much higher sampling rates than vibration analysis-based techniques for gearbox fault diagnosis. Therefore, it is questionable whether an AE-based technique would give a better or at least the same performance as the vibration analysis-based techniques using the same sampling rate. To answer the question, this paper presents a comparative study for gearbox tooth damage level diagnostics using AE and vibration measurements, the first known attempt to compare the gearbox fault diagnostic performance of AE- and vibration analysis-based approaches using the same sampling rate. Partial tooth cut faults are seeded in a gearbox test rig and experimentally tested in a laboratory. Results have shown that the AE-based approach has the potential to differentiate gear tooth damage levels in comparison with the vibration-based approach. While vibration signals are easily affected by mechanical resonance, the AE signals show more stable performance. PMID:24424467

Multi-frame image processing with panning cameras and moving subjects

NASA Astrophysics Data System (ADS)

Paolini, Aaron; Humphrey, John; Curt, Petersen; Kelmelis, Eric

2014-06-01

Imaging scenarios commonly involve erratic, unpredictable camera behavior or subjects that are prone to movement, complicating multi-frame image processing techniques. To address these issues, we developed three techniques that can be applied to multi-frame image processing algorithms in order to mitigate the adverse effects observed when cameras are panning or subjects within the scene are moving. We provide a detailed overview of the techniques and discuss the applicability of each to various movement types. In addition to this, we evaluated algorithm efficacy with demonstrated benefits using field test video, which has been processed using our commercially available surveillance product. Our results show that algorithm efficacy is significantly improved in common scenarios, expanding our software's operational scope. Our methods introduce little computational burden, enabling their use in real-time and low-power solutions, and are appropriate for long observation periods. Our test cases focus on imaging through turbulence, a common use case for multi-frame techniques. We present results of a field study designed to test the efficacy of these techniques under expanded use cases.

30 CFR 282.23 - Testing Plan.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR... lessee needs more information to develop a detailed Mining Plan than is obtainable under an approved... techniques or technology or mining equipment, or to determine environmental effects by a pilot test mining...

Imminent Engine Failure Probe Investigation.

DTIC Science & Technology

probe signature determination, development of data recording techniques, accumulation of data during durability testing of T56 or TF41 engines and...any other opportunistic gas turbine engine test. The electrostatic probe demonstrated some capability to detect engine distress in TF41 and T56 engines

Absolute measurements of large mirrors

NASA Astrophysics Data System (ADS)

Su, Peng

The ability to produce mirrors for large astronomical telescopes is limited by the accuracy of the systems used to test the surfaces of such mirrors. Typically the mirror surfaces are measured by comparing their actual shapes to a precision master, which may be created using combinations of mirrors, lenses, and holograms. The work presented here develops several optical testing techniques that do not rely on a large or expensive precision, master reference surface. In a sense these techniques provide absolute optical testing. The Giant Magellan Telescope (GMT) has been designed with a 350 m 2 collecting area provided by a 25 m diameter primary mirror made out from seven circular independent mirror segments. These segments create an equivalent f/0.7 paraboloidal primary mirror consisting of a central segment and six outer segments. Each of the outer segments is 8.4 m in diameter and has an off-axis aspheric shape departing 14.5 mm from the best-fitting sphere. Much of the work in this dissertation is motivated by the need to measure the surfaces or such large mirrors accurately, without relying on a large or expensive precision reference surface. One method for absolute testing describing in this dissertation uses multiple measurements relative to a reference surface that is located in different positions with respect to the test surface of interest. The test measurements are performed with an algorithm that is based on the maximum likelihood (ML) method. Some methodologies for measuring large flat surfaces in the 2 m diameter range and for measuring the GMT primary mirror segments were specifically developed. For example, the optical figure of a 1.6-m flat mirror was determined to 2 nm rms accuracy using multiple 1-meter sub-aperture measurements. The optical figure of the reference surface used in the 1-meter sub-aperture measurements was also determined to the 2 nm level. The optical test methodology for a 1.7-m off axis parabola was evaluated by moving several times the mirror under test in relation to the test system. The result was a separation of errors in the optical test system to those errors from the mirror under test. This method proved to be accurate to 12nm rms. Another absolute measurement technique discussed in this dissertation utilizes the property of a paraboloidal surface of reflecting rays parallel to its optical axis, to its focal point. We have developed a scanning pentaprism technique that exploits this geometry to measure off-axis paraboloidal mirrors such as the GMT segments. This technique was demonstrated on a 1.7 m diameter prototype and proved to have a precision of about 50 nm rms.

Development and comparison of projection and image space 3D nodule insertion techniques

NASA Astrophysics Data System (ADS)

Robins, Marthony; Solomon, Justin; Sahbaee, Pooyan; Samei, Ehsan

2016-04-01

This study aimed to develop and compare two methods of inserting computerized virtual lesions into CT datasets. 24 physical (synthetic) nodules of three sizes and four morphologies were inserted into an anthropomorphic chest phantom (LUNGMAN, KYOTO KAGAKU). The phantom was scanned (Somatom Definition Flash, Siemens Healthcare) with and without nodules present, and images were reconstructed with filtered back projection and iterative reconstruction (SAFIRE) at 0.6 mm slice thickness using a standard thoracic CT protocol at multiple dose settings. Virtual 3D CAD models based on the physical nodules were virtually inserted (accounting for the system MTF) into the nodule-free CT data using two techniques. These techniques include projection-based and image-based insertion. Nodule volumes were estimated using a commercial segmentation tool (iNtuition, TeraRecon, Inc.). Differences were tested using paired t-tests and R2 goodness of fit between the virtually and physically inserted nodules. Both insertion techniques resulted in nodule volumes very similar to the real nodules (<3% difference) and in most cases the differences were not statistically significant. Also, R2 values were all <0.97 for both insertion techniques. These data imply that these techniques can confidently be used as a means of inserting virtual nodules in CT datasets. These techniques can be instrumental in building hybrid CT datasets composed of patient images with virtually inserted nodules.

Development and Evaluation of an Online CO2 Evolution Test and a Multicomponent Biodegradation Test System

PubMed Central

Strotmann, Uwe; Reuschenbach, Peter; Schwarz, Helmut; Pagga, Udo

2004-01-01

Well-established biodegradation tests use biogenously evolved carbon dioxide (CO2) as an analytical parameter to determine the ultimate biodegradability of substances. A newly developed analytical technique based on the continuous online measurement of conductivity showed its suitability over other techniques. It could be demonstrated that the method met all criteria of established biodegradation tests, gave continuous biodegradation curves, and was more reliable than other tests. In parallel experiments, only small variations in the biodegradation pattern occurred. When comparing the new online CO2 method with existing CO2 evolution tests, growth rates and lag periods were similar and only the final degree of biodegradation of aniline was slightly lower. A further test development was the unification and parallel measurement of all three important summary parameters for biodegradation—i.e., CO2 evolution, determination of the biochemical oxygen demand (BOD), and removal of dissolved organic carbon (DOC)—in a multicomponent biodegradation test system (MCBTS). The practicability of this test method was demonstrated with aniline. This test system had advantages for poorly water-soluble and highly volatile compounds and allowed the determination of the carbon fraction integrated into biomass (heterotrophic yield). The integrated online measurements of CO2 and BOD systems produced continuous degradation curves, which better met the stringent criteria of ready biodegradability (60% biodegradation in a 10-day window). Furthermore the data could be used to calculate maximal growth rates for the modeling of biodegradation processes. PMID:15294794

Research and development of optical measurement techniques for aerospace propulsion research: A NASA Lewis Research Center perspective

NASA Technical Reports Server (NTRS)

Lesco, Daniel J.

1991-01-01

The applied research effort required to develop new nonintrusive measurement techniques capable of obtaining the data required by aerospace propulsion researchers and of operating in the harsh environments encountered in research and test facilities is discussed and illustrated through several ongoing projects at NASA's Lewis Research Center. Factors including length of development time, funding levels, and collaborative support from fluid-thermal researchers are cited. Progress in developing new instrumentation via a multi-path approach, including NASA research, grant, and government-sponsored research through mechanisms like the Small Business Innovative Research program, is also described.

LOX/Hydrocarbon Combustion Instability Investigation

NASA Technical Reports Server (NTRS)

Jensen, R. J.; Dodson, H. C.; Claflin, S. E.

1989-01-01

The LOX/Hydrocarbon Combustion Instability Investigation Program was structured to determine if the use of light hydrocarbon combustion fuels with liquid oxygen (LOX) produces combustion performance and stability behavior similar to the LOX/hydrogen propellant combination. In particular methane was investigated to determine if that fuel can be rated for combustion instability using the same techniques as previously used for LOX/hydrogen. These techniques included fuel temperature ramping and stability bomb tests. The hot fire program probed the combustion behavior of methane from ambient to subambient temperatures. Very interesting results were obtained from this program that have potential importance to future LOX/methane development programs. A very thorough and carefully reasoned documentation of the experimental data obtained is contained. The hot fire test logic and the associated tests are discussed. Subscale performance and stability rating testing was accomplished using 40,000 lb. thrust class hardware. Stability rating tests used both bombs and fuel temperature ramping techniques. The test program was successful in generating data for the evaluation of the methane stability characteristics relative to hydrogen and to anchor stability models. Data correlations, performance analysis, stability analyses, and key stability margin enhancement parameters are discussed.

Developing a technique to master multiplication facts 6 to 9 for year 5 pupils

NASA Astrophysics Data System (ADS)

Ahmat, Norhayati; Mohamed, Nurul Huda; Azmee, Nor Afzalina; Adham, Sarah Mohd

2017-05-01

This study was performed to enhance the mastery of multiplication facts 6 to 9 amongst the year 5 pupils. The samples of this study were 40 pupils of year 5 from one of primary school at Teluk Intan, Perak. The samples were divided into two groups, the control group and the treatment group where each group consists of 20 pupils respectively. In this study, new multiplication facts technique, known as `Teknik Sifir Jari' has been introduced to the treatment group. The objectives of the study are to test the effectiveness of the new technique and to increase multiplication fact fluency among pupils. The instruments that have been used in this study are the achievement tests (pre-test and post-test). The data obtained were collected and analyzed using SPSS version 21.A t-test had also been carried out to test the null hypothesis. The results showed that there was an increment in the students' achievement for the students who were taught using the `Teknik Sifir Jari'. Therefore, the `Teknik Sifir Jari' has proved its effectiveness to support students in mastering multiplication facts.

The Effect of Six Thinking Hats on Student Success in Teaching Subjects Related to Sustainable Development in Geography Classes

ERIC Educational Resources Information Center

Kaya, Mehmet Fatih

2013-01-01

This study aimed to assess the effectiveness of six thinking hats technique in teaching subjects related to sustainable development in geography classes. The study was in both a quantitative and qualitative form. The quantitative part of the study was designed according to pre-test, post-test control group research model, and in the qualitative…

Alternatives for Developing User Documentation for Applications Software

DTIC Science & Technology

1991-09-01

style that is designed to match adult reading behaviors, using reader-based writing techniques, developing effective graphics , creating reference aids...involves research, analysis, design , and testing. The writer must have a solid understanding of the technical aspects of the document being prepared, good...ABSTRACT The preparation of software documentation is an iterative process that involves research, analysis, design , and testing. The writer must have

Reverberation Chamber Uniformity Validation and Radiated Susceptibility Test Procedures for the NASA High Intensity Radiated Fields Laboratory

NASA Technical Reports Server (NTRS)

Koppen, Sandra V.; Nguyen, Truong X.; Mielnik, John J.

2010-01-01

The NASA Langley Research Center's High Intensity Radiated Fields Laboratory has developed a capability based on the RTCA/DO-160F Section 20 guidelines for radiated electromagnetic susceptibility testing in reverberation chambers. Phase 1 of the test procedure utilizes mode-tuned stirrer techniques and E-field probe measurements to validate chamber uniformity, determines chamber loading effects, and defines a radiated susceptibility test process. The test procedure is segmented into numbered operations that are largely software controlled. This document is intended as a laboratory test reference and includes diagrams of test setups, equipment lists, as well as test results and analysis. Phase 2 of development is discussed.

Solderability test system

DOEpatents

Yost, F.; Hosking, F.M.; Jellison, J.L.; Short, B.; Giversen, T.; Reed, J.R.

1998-10-27

A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time. 11 figs.

Practical input optimization for aircraft parameter estimation experiments. Ph.D. Thesis, 1990

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

1993-01-01

The object of this research was to develop an algorithm for the design of practical, optimal flight test inputs for aircraft parameter estimation experiments. A general, single pass technique was developed which allows global optimization of the flight test input design for parameter estimation using the principles of dynamic programming with the input forms limited to square waves only. Provision was made for practical constraints on the input, including amplitude constraints, control system dynamics, and selected input frequency range exclusions. In addition, the input design was accomplished while imposing output amplitude constraints required by model validity and considerations of safety during the flight test. The algorithm has multiple input design capability, with optional inclusion of a constraint that only one control move at a time, so that a human pilot can implement the inputs. It is shown that the technique can be used to design experiments for estimation of open loop model parameters from closed loop flight test data. The report includes a new formulation of the optimal input design problem, a description of a new approach to the solution, and a summary of the characteristics of the algorithm, followed by three example applications of the new technique which demonstrate the quality and expanded capabilities of the input designs produced by the new technique. In all cases, the new input design approach showed significant improvement over previous input design methods in terms of achievable parameter accuracies.

Learning to Read and Write the Drafting Way. Field Test Copy.

ERIC Educational Resources Information Center

California State Dept. of Education, Sacramento. Div. of Vocational Education.

This volume comprises instructional techniques that are designed for use with drafting students who demonstrate a need for additional instruction in the areas of reading, writing, math, and verbal and visual communication. Included in the guide are the following teacher-developed instructional techniques: a drafting crossword puzzle, tool bingo, a…

An analysis technique for testing log grades

Treesearch

Carl A. Newport; William G. O' Regan

1963-01-01

An analytical technique that may be used in evaluating log-grading systems is described. It also provides means of comparing two or more grading systems, or a proposed change with the system from which it was developed. The total volume and computed value of lumber from each sample log are the basic data used.

Exploring Techniques of Developing Writing Skill in IELTS Preparatory Courses: A Data-Driven Study

ERIC Educational Resources Information Center

Ostovar-Namaghi, Seyyed Ali; Safaee, Seyyed Esmail

2017-01-01

Being driven by the hypothetico-deductive mode of inquiry, previous studies have tested the effectiveness of theory-driven interventions under controlled experimental conditions to come up with universally applicable generalizations. To make a case in the opposite direction, this data-driven study aims at uncovering techniques and strategies…

CMOS array design automation techniques. [metal oxide semiconductors

NASA Technical Reports Server (NTRS)

Ramondetta, P.; Feller, A.; Noto, R.; Lombardi, T.

1975-01-01

A low cost, quick turnaround technique for generating custom metal oxide semiconductor arrays using the standard cell approach was developed, implemented, tested and validated. Basic cell design topology and guidelines are defined based on an extensive analysis that includes circuit, layout, process, array topology and required performance considerations particularly high circuit speed.

Optimization Techniques for Analysis of Biological and Social Networks

DTIC Science & Technology

2012-03-28

analyzing a new metaheuristic technique, variable objective search. 3. Experimentation and application: Implement the proposed algorithms , test and fine...alternative mathematical programming formulations, their theoretical analysis, the development of exact algorithms , and heuristics. Originally, clusters...systematic fashion under a unifying theoretical and algorithmic framework. Optimization, Complex Networks, Social Network Analysis, Computational

Investigation of the effects of external current systems on the MAGSAT data utilizing grid cell modeling techniques

NASA Technical Reports Server (NTRS)

Klumpar, D. M. (Principal Investigator)

1982-01-01

The status of the initial testing of the modeling procedure developed to compute the magnetic fields at satellite orbit due to current distributions in the ionosphere and magnetosphere is reported. The modeling technique utilizes a linear current element representation of the large scale space-current system.

Implementation project : strengthening a continuous steel girder bridge in Lakeport, Texas with post-installed shear connectors : Phase 1 : bridge strengthening design and load testing.

DOT National Transportation Integrated Search

2017-03-01

In Implementation Project 5-6719, a non-composite continuous steel girder bridge located in Lakeport, Texas will be strengthened using techniques developed in TxDOT Research Project 0-6719. This strengthening technique involves the use of post-instal...

Integration of Video-Based Demonstrations to Prepare Students for the Organic Chemistry Laboratory

ERIC Educational Resources Information Center

Nadelson, Louis S.; Scaggs, Jonathan; Sheffield, Colin; McDougal, Owen M.

2015-01-01

Consistent, high-quality introductions to organic chemistry laboratory techniques effectively and efficiently support student learning in the organic chemistry laboratory. In this work, we developed and deployed a series of instructional videos to communicate core laboratory techniques and concepts. Using a quasi-experimental design, we tested the…

The Fluorescent-Oil Film Method and Other Techniques for Boundary-Layer Flow Visualization

NASA Technical Reports Server (NTRS)

Loving, Donald L.; Katzoff, S.

1959-01-01

A flow-visualization technique, known as the fluorescent-oil film method, has been developed which appears to be generally simpler and to require less experience and development of technique than previously published methods. The method is especially adapted to use in the large high-powered wind tunnels which require considerable time to reach the desired test conditions. The method consists of smearing a film of fluorescent oil over a surface and observing where the thickness is affected by the shearing action of the boundary layer. These films are detected and identified, and their relative thicknesses are determined by use of ultraviolet light. Examples are given of the use of this technique. Other methods that show promise in the study of boundary-layer conditions are described. These methods include the use of a temperature-sensitive fluorescent paint and the use of a radiometer that is sensitive to the heat radiation from a surface. Some attention is also given to methods that can be used with a spray apparatus in front of the test model.

Spindle speed variation technique in turning operations: Modeling and real implementation

NASA Astrophysics Data System (ADS)

Urbikain, G.; Olvera, D.; de Lacalle, L. N. López; Elías-Zúñiga, A.

2016-11-01

Chatter is still one of the most challenging problems in machining vibrations. Researchers have focused their efforts to prevent, avoid or reduce chatter vibrations by introducing more accurate predictive physical methods. Among them, the techniques based on varying the rotational speed of the spindle (or SSV, Spindle Speed ​​Variation) have gained great relevance. However, several problems need to be addressed due to technical and practical reasons. On one hand, they can generate harmful overheating of the spindle especially at high speeds. On the other hand, the machine may be unable to perform the interpolation properly. Moreover, it is not trivial to select the most appropriate tuning parameters. This paper conducts a study of the real implementation of the SSV technique in turning systems. First, a stability model based on perturbation theory was developed for simulation purposes. Secondly, the procedure to realistically implement the technique in a conventional turning center was tested and developed. The balance between the improved stability margins and acceptable behavior of the spindle is ensured by energy consumption measurements. Mathematical model shows good agreement with experimental cutting tests.

Development of a new technique (ATP) for training visually impaired children in oral hygiene maintenance.

PubMed

Hebbal, M; Ankola, A V

2012-10-01

To develop a special oral health education technique and compare plaque scores before and after health education. Non-randomised before and after comparison trial without controls. The final study population comprised of 96 visually impaired children aged 6-18 years old. Silness and Loe plaque index scores were recorded at baseline. 'Audio tactile performance technique' (ATP Technique) a specially designed health education method was used to educate these children regarding oral hygiene maintenance. Periodic reinforcement of health education was performed at an interval of 9 months. Re-examination was carried out after 18 months of health education to assess plaque scores. Wilcoxon's sign rank test and paired t test was used to assess the difference between the scores before and after health education. There was increase in frequency of tooth brushing after health education. The mean plaque scores pre- and post-health education were 1.41 (+/-0.58) and 0.63 (+/-0.39) respectively. The difference was statistically significant (p<0.001). Visually impaired children could maintain an acceptable level of oral hygiene when taught using special customised methods.

The effect of sea-water and fresh-water soaking on the quality of Eucheuma sp. syrup and pudding

NASA Astrophysics Data System (ADS)

Novianty, H.; Herandarudewi, S. M. C.

2018-04-01

Eucheuma alvarezii is one of marine commodity with great opportunities to be developed in Indonesia. This seaweed can be used as an additional material in cosmetic and pharmaceutical products or for syrup and pudding. Post-harvest technique conducted by the seaweed farmers will affects the quality of dried and processed products. The purpose of this study was to observe the effect of post harvest technique on the quality of dried seaweed and hedonic test (favorable test) of processed product (syrup and pudding). This study was conducted using descriptive method. The study compared dried, syrup, and puddings from two differents post-harvest technique, between salt and fresh-water draining products. The results showed that fresh-water draining technique obtained better quality results organoleptic test. The results showed that panelist prefered the fresh-water drained products of syrup and pudding. The hedonic scores were much higher for the fresh-water drained products in all three catagories of color, taste, and smell.

Generating Test Templates via Automated Theorem Proving

NASA Technical Reports Server (NTRS)

Kancherla, Mani Prasad

1997-01-01

Testing can be used during the software development process to maintain fidelity between evolving specifications, program designs, and code implementations. We use a form of specification-based testing that employs the use of an automated theorem prover to generate test templates. A similar approach was developed using a model checker on state-intensive systems. This method applies to systems with functional rather than state-based behaviors. This approach allows for the use of incomplete specifications to aid in generation of tests for potential failure cases. We illustrate the technique on the cannonical triangle testing problem and discuss its use on analysis of a spacecraft scheduling system.

Development of an inflatable radiator system. [for space shuttles

NASA Technical Reports Server (NTRS)

Leach, J. W.

1976-01-01

Conceptual designs of an inflatable radiator system developed for supplying short duration supplementary cooling of space vehicles are described along with parametric trade studies, materials evaluation/selection studies, thermal and structural analyses, and numerous element tests. Fabrication techniques developed in constructing the engineering models and performance data from the model thermal vacuum tests are included. Application of these data to refining the designs of the flight articles and to constructing a full scale prototype radiator is discussed.

A method for monitoring nuclear absorption coefficients of aviation fuels

NASA Technical Reports Server (NTRS)

Sprinkle, Danny R.; Shen, Chih-Ping

1989-01-01

A technique for monitoring variability in the nuclear absorption characteristics of aviation fuels has been developed. It is based on a highly collimated low energy gamma radiation source and a sodium iodide counter. The source and the counter assembly are separated by a geometrically well-defined test fuel cell. A computer program for determining the mass attenuation coefficient of the test fuel sample, based on the data acquired for a preset counting period, has been developed and tested on several types of aviation fuel.

Quantitative ultrasonic testing of acoustically anisotropic materials with verification on austenitic and dissimilar weld joints

NASA Astrophysics Data System (ADS)

Boller, C.; Pudovikov, S.; Bulavinov, A.

2012-05-01

Austenitic stainless steel materials are widely used in a variety of industry sectors. In particular, the material is qualified to meet the design criteria of high quality in safety related applications. For example, the primary loop of the most of the nuclear power plants in the world, due to high durability and corrosion resistance, is made of this material. Certain operating conditions may cause a range of changes in the integrity of the component, and therefore require nondestructive testing at reasonable intervals. These in-service inspections are often performed using ultrasonic techniques, in particular when cracking is of specific concern. However, the coarse, dendritic grain structure of the weld material, formed during the welding process, is extreme and unpredictably anisotropic. Such structure is no longer direction-independent to the ultrasonic wave propagation; therefore, the ultrasonic beam deflects and redirects and the wave front becomes distorted. Thus, the use of conventional ultrasonic testing techniques using fixed beam angles is very limited and the application of ultrasonic Phased Array techniques becomes desirable. The "Sampling Phased Array" technique, invented and developed by Fraunhofer IZFP, allows the acquisition of time signals (A-scans) for each individual transducer element of the array along with fast image reconstruction techniques based on synthetic focusing algorithms. The reconstruction considers the sound propagation from each image pixel to the individual sensor element. For anisotropic media, where the sound beam is deflected and the sound path is not known a-priori, a novel phase adjustment technique called "Reverse Phase Matching" is implemented. By taking into account the anisotropy and inhomogeneity of the weld structure, a ray tracing algorithm for modeling the acoustic wave propagation and calculating the sound propagation time is applied. This technique can be utilized for 2D and 3D real time image reconstruction. The "Gradient Constant Descent Method" (GECDM), an iterative algorithm, is implemented, which is essential for examination of inhomogeneous anisotropic media having unknown properties (elastic constants). The Sampling Phased Array technique with Reverse Phase Matching extended by GECDM-technique determines unknown elastic constants and provides reliable and efficient quantitative flaw detection in the austenitic welds. The validation of ray-tracing algorithm and GECDM-method is performed by number of experiments on test specimens with artificial as well as natural material flaws. A mechanized system for ultrasonic testing of stainless steel and dissimilar welds is developed. The system works on both conventional and Sampling Phased Array techniques. The new frontend ultrasonic unit with optical data link allows the 3D visualization of the inspection results in real time.

Advanced optical position sensors for magnetically suspended wind tunnel models

NASA Technical Reports Server (NTRS)

Lafleur, S.

1985-01-01

A major concern to aerodynamicists has been the corruption of wind tunnel test data by model support structures, such as stings or struts. A technique for magnetically suspending wind tunnel models was considered by Tournier and Laurenceau (1957) in order to overcome this problem. This technique is now implemented with the aid of a Large Magnetic Suspension and Balance System (LMSBS) and advanced position sensors for measuring model attitude and position within the test section. Two different optical position sensors are discussed, taking into account a device based on the use of linear CCD arrays, and a device utilizing area CID cameras. Current techniques in image processing have been employed to develop target tracking algorithms capable of subpixel resolution for the sensors. The algorithms are discussed in detail, and some preliminary test results are reported.

Numerical description of cavitation on axisymmetric bodies

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

Hickox, C.E.; Hailey, C.E.; Wolfe, W.P.

1988-01-01

This paper reports on ongoing studies which are directed toward the development of predictive techniques for the modeling of steady cavitation on axisymmetric bodies. The primary goal of the modeling effort is the prediction of cavity shape and pressure distribution from which forces and moments can be calculated. Here we present an overview of the modeling techniques developed and compare predictions with experimental data obtained from water tunnel tests for both limited and supercavitation. 14 refs., 4 figs.

Summary of flat-plate solar array project documentation. Abstracts of published documents, 1975 to June 1982

NASA Technical Reports Server (NTRS)

1982-01-01

Technologies that will enable the private sector to manufacture and widely use photovoltaic systems for the generation of electricity in residential, commercial, industrial, and government applications at a cost per watt that is competitive with other means is investigated. Silicon refinement processes, advanced silicon sheet growth techniques, solar cell development, encapsulation, automated fabrication process technology, advanced module/array design, and module/array test and evaluation techniques are developed.

Computer assisted audit techniques for UNIX (UNIX-CAATS)

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

Polk, W.T.

1991-12-31

Federal and DOE regulations impose specific requirements for internal controls of computer systems. These controls include adequate separation of duties and sufficient controls for access of system and data. The DOE Inspector General`s Office has the responsibility to examine internal controls, as well as efficient use of computer system resources. As a result, DOE supported NIST development of computer assisted audit techniques to examine BSD UNIX computers (UNIX-CAATS). These systems were selected due to the increasing number of UNIX workstations in use within DOE. This paper describes the design and development of these techniques, as well as the results ofmore » testing at NIST and the first audit at a DOE site. UNIX-CAATS consists of tools which examine security of passwords, file systems, and network access. In addition, a tool was developed to examine efficiency of disk utilization. Test results at NIST indicated inadequate password management, as well as weak network resource controls. File system security was considered adequate. Audit results at a DOE site indicated weak password management and inefficient disk utilization. During the audit, we also found improvements to UNIX-CAATS were needed when applied to large systems. NIST plans to enhance the techniques developed for DOE/IG in future work. This future work would leverage currently available tools, along with needed enhancements. These enhancements would enable DOE/IG to audit large systems, such as supercomputers.« less

Computer assisted audit techniques for UNIX (UNIX-CAATS)

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

Polk, W.T.

1991-01-01

Federal and DOE regulations impose specific requirements for internal controls of computer systems. These controls include adequate separation of duties and sufficient controls for access of system and data. The DOE Inspector General's Office has the responsibility to examine internal controls, as well as efficient use of computer system resources. As a result, DOE supported NIST development of computer assisted audit techniques to examine BSD UNIX computers (UNIX-CAATS). These systems were selected due to the increasing number of UNIX workstations in use within DOE. This paper describes the design and development of these techniques, as well as the results ofmore » testing at NIST and the first audit at a DOE site. UNIX-CAATS consists of tools which examine security of passwords, file systems, and network access. In addition, a tool was developed to examine efficiency of disk utilization. Test results at NIST indicated inadequate password management, as well as weak network resource controls. File system security was considered adequate. Audit results at a DOE site indicated weak password management and inefficient disk utilization. During the audit, we also found improvements to UNIX-CAATS were needed when applied to large systems. NIST plans to enhance the techniques developed for DOE/IG in future work. This future work would leverage currently available tools, along with needed enhancements. These enhancements would enable DOE/IG to audit large systems, such as supercomputers.« less

Triaxial testing system for pressure core analysis using image processing technique

NASA Astrophysics Data System (ADS)

Yoneda, J.; Masui, A.; Tenma, N.; Nagao, J.

2013-11-01

In this study, a newly developed innovative triaxial testing system to investigate strength, deformation behavior, and/or permeability of gas hydrate bearing-sediments in deep sea is described. Transport of the pressure core from the storage chamber to the interior of the sealing sleeve of a triaxial cell without depressurization was achieved. An image processing technique was used to capture the motion and local deformation of a specimen in a transparent acrylic triaxial pressure cell and digital photographs were obtained at each strain level during the compression test. The material strength was successfully measured and the failure mode was evaluated under high confining and pore water pressures.

Slow crack growth in spinel in water

NASA Technical Reports Server (NTRS)

Schwantes, S.; Elber, W.

1983-01-01

Magnesium aluminate spinel was tested in a water environment at room temperature to establish its slow crack-growth behavior. Ring specimens with artificial flaws on the outside surface were loaded hydraulically on the inside surface. The time to failure was measured. Various precracking techniques were evaluated and multiple precracks were used to minimize the scatter in the static fatigue tests. Statistical analysis techniques were developed to determine the strength and crack velocities for a single flaw. Slow crack-growth rupture was observed at stress intensities as low as 70 percent of K sub c. A strengthening effect was observed in specimens that had survived long-time static fatigue tests.

Bladed disc crack diagnostics using blade passage signals

NASA Astrophysics Data System (ADS)

Hanachi, Houman; Liu, Jie; Banerjee, Avisekh; Koul, Ashok; Liang, Ming; Alavi, Elham

2012-12-01

One of the major potential faults in a turbo fan engine is the crack initiation and propagation in bladed discs under cyclic loads that could result in the breakdown of the engines if not detected at an early stage. Reliable fault detection techniques are therefore in demand to reduce maintenance cost and prevent catastrophic failures. Although a number of approaches have been reported in the literature, it remains very challenging to develop a reliable technique to accurately estimate the health condition of a rotating bladed disc. Correspondingly, this paper presents a novel technique for bladed disc crack detection through two sequential signal processing stages: (1) signal preprocessing that aims to eliminate the noises in the blade passage signals; (2) signal postprocessing that intends to identify the crack location. In the first stage, physics-based modeling and interpretation are established to help characterize the noises. The crack initiation can be determined based on the calculated health monitoring index derived from the sinusoidal effects. In the second stage, the crack is located through advanced detrended fluctuation analysis of the preprocessed data. The proposed technique is validated using a set of spin rig test data (i.e. tip clearance and time of arrival) that was acquired during a test conducted on a bladed military engine fan disc. The test results have demonstrated that the developed technique is an effective approach for identifying and locating the incipient crack that occurs at the root of a bladed disc.

Design development of graphite primary structures enables SSTO success

NASA Astrophysics Data System (ADS)

Biagiotti, V. A.; Yahiro, J. S.; Suh, Daniel E.; Hodges, Eric R.; Prior, Donald J.

1997-01-01

This paper describes the development of a graphite composite wing and a graphite composite intertank primary structure for application toward Single-Stage to Orbit space vehicles such as those under development in NASA's X-33/Reusable Launch Vehicle (RLV) Program. The trade study and designs are based on a Rockwell vertical take-off and horizontal landing (VTHL) wing-body RLV vehicle. Northrop Grumman's approach using a building block development technique is described. Composite Graphite/Bismaleimide (Gr/BMI) material characterization test results are presented. Unique intertank and wing composite subcomponent test article designs are described and test results to date are presented. Wing and intertank Full Scale Section Test Article (FSTA) objectives and designs are outlined. Trade studies, supporting building block testing, and FSTA demonstrations combine to develop graphite primary structure composite technology that enables developing X-33/RLV design programs to meet critical SSTO structural weight and operations performance criteria.

Development of a breadboard model correlation interferometer for the carbon monoxide pollution experiment

NASA Technical Reports Server (NTRS)

Bortner, M. H.; Dick, R.; Goldstein, H. W.; Grenda, R. N.; Levy, G. M.

1973-01-01

The breadboard model of the correlation interferometer for the Carbon Monoxide Pollution Experiment has been designed, fabricated, and tested. Laboratory, long-path, and atmospheric tests which were performed show the technique to be a feasible method for obtaining a global carbon monoxide map and a vertical carbon monoxide profile and similar information is readily obtainable for methane as well. In addition, the technique is readily applicable to other trace gases by minor instrumental changes. As shown by the results and the conclusions, it has been determined that CO and CH4 data can be obtained with an accuracy of 10% using this technique on the spectral region around 2.3 microns.

EC MoDeRn Project: In-situ Demonstration of Innovative Monitoring Technologies for Geological Disposal - 12053

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

Breen, B.J.; Garcia-Sineriz, J.L.; Maurer, H.

2012-07-01

Monitoring to provide information on the evolution of geological disposal presents several challenges. The 4-year, euros M 5, EC MoDeRn Project (http://www.modern-fp7.eu/), which commenced in 2009, addresses monitoring processes, state-of-the-art technology and innovative research and development of monitoring techniques. This paper discusses some of the key drivers for the development of innovative monitoring techniques and provides outlines of the demonstration programmes being conducted within MoDeRn. The aim is to develop these innovative monitoring techniques and to demonstrate them under realistic conditions present in underground laboratories. These demonstration projects, applying a range of different monitoring techniques, are being carried out atmore » underground research facilities in different geological environments at HADES URL in Belgium (plastic clay), Bure in France (indurated clay) and at Grimsel Test Site (granite) in Switzerland. These are either built upon existing infrastructure (EC ESDRED Low pH shotcrete and TEM experiments at Grimsel; and PRACLAY experiment and underground galleries in HADES) or will be attached to infrastructure that is being developed and financed by resources outside of this project (mock-up disposal cell in Bure). At Grimsel Test Site, cross-hole and hole-to-tunnel seismic methods are being employed as a means to monitor induced changes in an artificially saturated bentonite wall confined behind a shotcrete plug. Recognising the limitations for travel-time tomography for monitoring a disposal cell, full waveform inversion techniques are being employed to enhance the capacity to monitor remote from the excavation. At the same Grimsel location, an investigation will be conducted of the potential for using a high frequency wireless (HFW) sensor network embedded within the barrier system; this will include the possibility of providing energy remotely to isolated sensors. At the HADES URL, the monitoring programme will utilise the PRACLAY gallery equipped to simulate a disposal gallery for heat-generating high-level waste evaluating fibre-optic based sensing techniques, including distributed sensing for thermal distribution and long-term reliability in harsh conditions. It also includes the potential to improve the treatment of signals from micro-seismic monitoring to enable enhanced understanding of the evolution around the gallery following its excavation due to ventilation, saturation and heating, and to image a water-bearing concretion layer. HADES URL will also be used to test wireless techniques to transmit monitoring data from the underground to the surface. The main focus of this contribution is to evaluate magneto-inductive data transmission; and to optimise energy usage. At the Bure underground facility in France, monitoring systems have been developed and will be embedded into the steel liner for the mock-up high-level waste disposal tunnel. The aim of this programme is to establish the capacity to conduct integrated monitoring activities inside the disposal cell, on the cell liner and in the near-field and to assess the capability of the monitoring to withstand construction and liner emplacement procedures. These projects, which are supported by focused development and testing of the monitoring systems, will allow the testing of both the effectiveness of these techniques applied to disposal situations and to understand the limits of these monitoring technologies. This approach should also enhance the confidence of key stakeholders in the ability to understand/confirm the changes occurring within a disposal cell. In addition, remote or 'non-intrusive' monitoring technologies are evaluated to provide a means of enhancing understanding of what is occurring in an isolated disposal cell. The projects also test solutions for embedded monitoring systems in challenging (risk of damage) situations. The outputs from this work will lead to improved understanding of these state-of-the-art techniques and allow focused development of those techniques beneficial to future monitoring programmes. It is also planned, as part of the MoDeRn programme of stakeholder engagement to show some of these monitoring demonstrations to lay stakeholders in order to receive their feed-back on the approach taken and their views on the value of this work. This feedback will help improve our understanding of how this work and future work on monitoring can be more effectively communicated. (authors)« less

L-Band Microwave Experiment On Russian Investigational Satellite, First Results And Comparison With SMOS Data

NASA Astrophysics Data System (ADS)

Smirnov, M.; Khaldin, A.

2013-12-01

The main scientific objective of mission with Zond-PP on Russian investigational satellite MKA-FKI No1 is development of techniques for retrieval: sea salinity in open oceans, soil moisture in global scales, vegetation state characteristics, sea ice characteristics. At the beginning stage of space experiments the main goals were to develop and test new space microwave radiometric instrument in order to solve technical objectives: investigation of RFI in L-band all over the globe, development and testing in-flight calibration techniques and others. First obtained results of our observations are presented. Zond-PP results were compared with MIRAS. For comparison were used results of brightness temperatures measurements obtained from Zond-PP and MIRAS in the same regions with minimal time difference. Results of comparison show general accordance in the brightness temperatures levels.

Development of acoustic emission evaluation method for repaired prestressed concrete bridge girders.

DOT National Transportation Integrated Search

2011-06-01

Acoustic emission (AE) monitoring has proven to be a useful nondestructive testing tool in ordinary reinforced concrete beams. Over the past decade, however, the technique has also been used to test other concrete structures. It has been seen that ac...

1000542

NASA Image and Video Library

2010-04-13

HORACE STORNG (AEROSPACE ENGINEER, ER31 PROPULSION TURBOMACHINERY DESIGN & DEVELOPMENT BRANCH) ADJUSTS A UNIQUE MECHANICAL TEST SETUP THAT MEASURES STRAIN ON A SINGLE SAMPLE, USING TWO DIFFERENT TECHNIQUES AT THE SAME TIME. THE TEST FIXTURE HOLDS A SPECIMEN THAT REPRESENTS A LIQUID OXYGEN (LOX) BEARING FROM THE J2-X ENGINE

Microprocessor Seminar, phase 2

NASA Technical Reports Server (NTRS)

Scott, W. R.

1977-01-01

Workshop sessions and papers were devoted to various aspects of microprocessor and large scale integrated circuit technology. Presentations were made on advanced LSI developments for high reliability military and NASA applications. Microprocessor testing techniques were discussed, and test data were presented. High reliability procurement specifications were also discussed.

Creep fatigue life prediction for engine hot section materials (isotropic)

NASA Technical Reports Server (NTRS)

Nelson, R. S.; Levan, G. W.; Harvey, P. R.

1992-01-01

This Final Report covers the activities completed under the optional program of the NASA HOST Contract, NAS3-23288. The initial effort of the optional program was report-in NASA CR189221, which consisted of high temperature strain controlled fatigue tests to study the effects of thermomechanical fatigue, multiaxial loading, reactive environments, and imposed stresses. The baseline alloy used in the tests included B1900+Hf (with or without coating) and wrought INCO 718. Tests conducted on B1900+Hf included environmental tests using various atmospheres (75 psig oxygen, purified argon, or block exposures) and specimen tests of wrought INCO 718 included tensile, creep, stress rupture, TMF, multiaxial, and mean stress tests. Results of these testings were used to calibrate a CDA model for INCO 718 alloy and to develop modifications or corrections to the CDA model to handle additional failure mechanisms. The Socie parameter was found to provide the best correlation for INCO multiaxial loading. Microstructural evaluations consisting of optical, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) techniques, and surface replication techniques to determine crack initiation lives provided data which were used to develop life prediction models.

Full-Field Strain Methods for Investigating Failure Mechanisms in Triaxial Braided Composites

NASA Technical Reports Server (NTRS)

Littell, Justin D.; Binienda, Wieslaw K.; Goldberg, Robert K.; Roberts, Gary D.

2008-01-01

Recent advancements in braiding technology have led to commercially viable manufacturing approaches for making large structures with complex shape out of triaxial braided composite materials. In some cases, the static load capability of structures made using these materials has been higher than expected based on material strength properties measured using standard coupon tests. A more detailed investigation of deformation and failure processes in large-unit-cell-size triaxial braid composites is needed to evaluate the applicability of standard test methods for these materials and to develop alternative testing approaches. This report presents some new techniques that have been developed to investigate local deformation and failure using digital image correlation techniques. The methods were used to measure both local and global strains during standard straight-sided coupon tensile tests on composite materials made with 12- and 24-k yarns and a 0 /+60 /-60 triaxial braid architecture. Local deformation and failure within fiber bundles was observed and correlations were made between these local failures and global composite deformation and strength.

Technique for Evaluating the Erosive Properties of Ablative Internal Insulation Materials

NASA Technical Reports Server (NTRS)

McComb, J. C.; Hitner, J. M.

1989-01-01

A technique for determining the average erosion rate versus Mach number of candidate internal insulation materials was developed for flight motor applications in 12 inch I.D. test firing hardware. The method involved the precision mounting of a mechanical measuring tool within a conical test cartridge fabricated from either a single insulation material or two non-identical materials each of which constituted one half of the test cartridge cone. Comparison of the internal radii measured at nine longitudinal locations and between eight to thirty two azimuths, depending on the regularity of the erosion pattern before and after test firing, permitted calculation of the average erosion rate and Mach number. Systematic criteria were established for identifying erosion anomalies such as the formation of localized ridges and for excluding such anomalies from the calculations. The method is discussed and results presented for several asbestos-free materials developed in-house for the internal motor case insulation in solid propellant rocket motors.

Antenna-coupled Superconducting Bolometers for Observations of the Cosmic Microwave Background Polarization

NASA Astrophysics Data System (ADS)

Myers, Michael James

We describe the development of a novel millimeter-wave cryogenic detector. The device integrates a planar antenna, superconducting transmission line, bandpass filter, and bolometer onto a single silicon wafer. The bolometer uses a superconducting Transition-Edge Sensor (TES) thermistor, which provides substantial advantages over conventional semiconductor bolometers. The detector chip is fabricated using standard micro-fabrication techniques. This highly-integrated detector architecture is particularly well-suited for use in the de- velopment of polarization-sensitive cryogenic receivers with thousands of pixels. Such receivers are needed to meet the sensitivity requirements of next-generation cosmic microwave background polarization experiments. The design, fabrication, and testing of prototype array pixels are described. Preliminary considerations for a full array design are also discussed. A set of on-chip millimeter-wave test structures were developed to help understand the performance of our millimeter-wave microstrip circuits. These test structures produce a calibrated transmission measurement for an arbitrary two-port circuit using optical techniques, rather than a network analyzer. Some results of fabricated test structures are presented.

A status report on NASA general aviation stall/spin flight testing

NASA Technical Reports Server (NTRS)

Patton, J. M., Jr.

1980-01-01

The NASA Langley Research Center has undertaken a comprehensive program involving spin tunnel, static and rotary balance wind tunnel, full-scale wind tunnel, free flight radio control model, flight simulation, and full-scale testing. Work underway includes aerodynamic definition of various configurations at high angles of attack, testing of stall and spin prevention concepts, definition of spin and spin recovery characteristics, and development of test techniques and emergency spin recovery systems. This paper presents some interesting results to date for the first aircraft (low-wing, single-engine) in the program, in the areas of tail design, wing leading edge design, mass distribution, center of gravity location, and small airframe changes, with associated pilot observations. The design philosophy of the spin recovery parachute system is discussed in addition to test techniques.

Application of Eddy Current Techniques for Orbiter Reinforced Carbon-Carbon Structural Health Monitoring

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Simpson, John

2005-01-01

The development and application of advanced nondestructive evaluation techniques for the Reinforced Carbon-Carbon (RCC) components of the Space Shuttle Orbiter Leading Edge Structural Subsystem (LESS) was identified as a crucial step toward returning the shuttle fleet to service. In order to help meet this requirement, eddy current techniques have been developed for application to RCC components. Eddy current technology has been found to be particularly useful for measuring the protective coating thickness over the reinforced carbon-carbon and for the identification of near surface cracking and voids in the RCC matrix. Testing has been performed on as manufactured and flown RCC components with both actual and fabricated defects representing impact and oxidation damage. Encouraging initial results have led to the development of two separate eddy current systems for in-situ RCC inspections in the orbiter processing facility. Each of these systems has undergone blind validation testing on a full scale leading edge panel, and recently transitioned to Kennedy Space Center to be applied as a part of a comprehensive RCC inspection strategy to be performed in the orbiter processing facility after each shuttle flight.

Radar data smoothing filter study

NASA Technical Reports Server (NTRS)

White, J. V.

1984-01-01

The accuracy of the current Wallops Flight Facility (WFF) data smoothing techniques for a variety of radars and payloads is examined. Alternative data reduction techniques are given and recommendations are made for improving radar data processing at WFF. A data adaptive algorithm, based on Kalman filtering and smoothing techniques, is also developed for estimating payload trajectories above the atmosphere from noisy time varying radar data. This algorithm is tested and verified using radar tracking data from WFF.

Fade Mitigation Techniques at Ka-Band

NASA Technical Reports Server (NTRS)

Dissanayake, Asoka (Editor)

1996-01-01

Rain fading is the dominant propagation impairment affecting Ka-band satellite links and rain fade mitigation is a key element in the design of Ka-band satellite networks. Some of the common fade mitigation techniques include: power control, diversity, adaptive coding, and resource sharing. The Advanced Communications Technology Satellite (ACTS) provides an excellent opportunity to develop and test Ka-band rain impairment amelioration techniques. Up-link power control and diversity are discussed in this paper.

Further Developments of the Fringe-Imaging Skin Friction Technique

NASA Technical Reports Server (NTRS)

Zilliac, Gregory C.

1996-01-01

Various aspects and extensions of the Fringe-Imaging Skin Friction technique (FISF) have been explored through the use of several benchtop experiments and modeling. The technique has been extended to handle three-dimensional flow fields with mild shear gradients. The optical and imaging system has been refined and a PC-based application has been written that has made it possible to obtain high resolution skin friction field measurements in a reasonable period of time. The improved method was tested on a wingtip and compared with Navier-Stokes computations. Additionally, a general approach to interferogram-fringe spacing analysis has been developed that should have applications in other areas of interferometry. A detailed error analysis of the FISF technique is also included.

The development of an Infrared Environmental System for TOPEX Solar Panel Testing

NASA Technical Reports Server (NTRS)

Noller, E.

1994-01-01

Environmental testing and flight qualification of the TOPEX/POSEIDON spacecraft solar panels were performed with infrared (IR) lamps and a control system that were newly designed and integrated. The basic goal was more rigorous testing of the costly panels' new composite-structure design without jeopardizing their safety. The technique greatly reduces the costs and high risks of testing flight solar panels.

Design, development and testing of a low-cost sEMG system and its use in recording muscle activity in human gait.

PubMed

Supuk, Tamara Grujic; Skelin, Ana Kuzmanic; Cic, Maja

2014-05-07

Surface electromyography (sEMG) is an important measurement technique used in biomechanical, rehabilitation and sport environments. In this article the design, development and testing of a low-cost wearable sEMG system are described. The hardware architecture consists of a two-cascade small-sized bioamplifier with a total gain of 2,000 and band-pass of 3 to 500 Hz. The sampling frequency of the system is 1,000 Hz. Since real measured EMG signals are usually corrupted by various types of noises (motion artifacts, white noise and electromagnetic noise present at 50 Hz and higher harmonics), we have tested several denoising techniques, both on artificial and measured EMG signals. Results showed that a wavelet-based technique implementing Daubechies5 wavelet and soft sqtwolog thresholding is the most appropriate for EMG signals denoising. To test the system performance, EMG activities of six dominant muscles of ten healthy subjects during gait were measured (gluteus maximus, biceps femoris, sartorius, rectus femoris, tibialis anterior and medial gastrocnemius). The obtained EMG envelopes presented against the duration of gait cycle were compared favourably with the EMG data available in the literature, suggesting that the proposed system is suitable for a wide range of applications in biomechanics.

Design, Development and Testing of a Low-Cost sEMG System and Its Use in Recording Muscle Activity in Human Gait

PubMed Central

Supuk, Tamara Grujic; Skelin, Ana Kuzmanic; Cic, Maja

2014-01-01

Surface electromyography (sEMG) is an important measurement technique used in biomechanical, rehabilitation and sport environments. In this article the design, development and testing of a low-cost wearable sEMG system are described. The hardware architecture consists of a two-cascade small-sized bioamplifier with a total gain of 2,000 and band-pass of 3 to 500 Hz. The sampling frequency of the system is 1,000 Hz. Since real measured EMG signals are usually corrupted by various types of noises (motion artifacts, white noise and electromagnetic noise present at 50 Hz and higher harmonics), we have tested several denoising techniques, both on artificial and measured EMG signals. Results showed that a wavelet—based technique implementing Daubechies5 wavelet and soft sqtwolog thresholding is the most appropriate for EMG signals denoising. To test the system performance, EMG activities of six dominant muscles of ten healthy subjects during gait were measured (gluteus maximus, biceps femoris, sartorius, rectus femoris, tibialis anterior and medial gastrocnemius). The obtained EMG envelopes presented against the duration of gait cycle were compared favourably with the EMG data available in the literature, suggesting that the proposed system is suitable for a wide range of applications in biomechanics. PMID:24811078

Investigation of electroforming techniques. [fabrication of regeneratively cooled thrust chambers

NASA Technical Reports Server (NTRS)

Malone, G. A.

1975-01-01

Copper and nickel electroforming was examined for the purpose of establishing the necessary processes and procedures for repeatable, successful fabrication of the outer structures of regeneratively cooled thrust chambers. The selection of electrolytes for copper and nickel deposition is described. The development studies performed to refine and complete the processes necessary for successful chamber shell fabrication and the testing employed to verify the applicability of the processes and procedures to small scale hardware are described. Specifications were developed to afford a guideline for the electroforming of high quality outer shells on regeneratively cooled thrust chamber liners. Test results indicated repeatable mechanical properties could be produced in copper deposits from the copper sulfate electrolyte with periodic current reversal and in nickel deposits from the sulfamate solution. Use of inert, removable channel fillers and the conductivizing of such is described. Techniques (verified by test) which produce high integrity bonds to copper and copper alloy liners are discussed.

Advanced Platform for Development and Evaluation of Grid Interconnection Systems Using Hardware-in-the-Loop: Part III - Grid Interconnection System Evaluator

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

Lundstrom, B.; Shirazi, M.; Coddington, M.

2013-01-01

This paper describes a Grid Interconnection System Evaluator (GISE) that leverages hardware-in-the-loop (HIL) simulation techniques to rapidly evaluate the grid interconnection standard conformance of an ICS according to the procedures in IEEE Std 1547.1. The architecture and test sequencing of this evaluation tool, along with a set of representative ICS test results from three different photovoltaic (PV) inverters, are presented. The GISE adds to the National Renewable Energy Laboratory's (NREL) evaluation platform that now allows for rapid development of ICS control algorithms using controller HIL (CHIL) techniques, the ability to test the dc input characteristics of PV-based ICSs through themore » use of a PV simulator capable of simulating real-world dynamics using power HIL (PHIL), and evaluation of ICS grid interconnection conformance.« less

A pressure-packer system for conducting rising head tests in water table wells

USGS Publications Warehouse

Levy, Benjamin S.; Pannell, Lawrence J.; Dadoly, John P.

1993-01-01

The pressure system developed for fully-saturated well screens has been modified for conducting rising head tests in water table wells installed in highly permeable aquifers. The pressure system consists of a compressed air source and 1 inch diameter PVC piping with a packer attached at the end. The pressure system was evaluated in a series of rising head tests conducted in a well at a Superfund site in New England. The well was tested with slugs and with the pressure system. Within each technique, estimates of hydraulic conductivity showed no difference. Comparison of hydraulic conductivity estimates between techniques (slug test vs. pressure test) showed differences due to stratigraphy. The interval tested using slug tests crossed two stratigraphic units; the pressure system tested only one of these units. We conclude that the pressure system may be used to characterize the vertical hydraulic conductivity distribution in a series of successive tests by changing the packer position and the screened interval tested.

Use of non-standardised micro-destructive techniques in the characterization of traditional construction materials

NASA Astrophysics Data System (ADS)

Ioannou, Ioannis; Theodoridou, Magdalini; Modestou, Sevasti; Fournari, Revecca; Dagrain, Fabrice

2013-04-01

The characterization of material properties and the diagnosis of their state of weathering and conservation are three of the most important steps in the field of cultural heritage preservation. Several standardised experimental methods exist, especially for determining the material properties and their durability. However, they are limited in their application by the required size of test specimens and the controlled laboratory conditions needed to undertake the tests; this is especially true when the materials under study constitute immovable parts of heritage structures. The current use of other advanced methods of analysis, such as imaging techniques, in the aforementioned field of research offers invaluable results. However, these techniques may not always be accessible to the wider research community due to their complex nature and relatively high cost of application. This study presents innovative applications of two recently developed cutting techniques; the portable Drilling Resistance Measuring System (DRMS) and the scratch tool. Both methods are defined as micro-destructive, since they only destroy a very small portion of sample material. The general concept of both methods lies within the forces needed to cut a material by linear (scratch tool) or rotational (DRMS) cutting action; these forces are related to the mechanical properties of the material and the technological parameters applied on the tool. Therefore, for a given testing configuration, the only parameter influencing the forces applied is the strength of the material. These two techniques have been used alongside a series of standardised laboratory tests aiming at the correlation of various stone properties (density, porosity, dynamic elastic modulus and uniaxial compressive strength). The results prove the potential of both techniques in assessing the uniaxial compressive strength of stones. The scratch tool has also been used effectively to estimate the compressive strength of mud bricks. It therefore follows that both micro-destructive techniques may prove useful in the physico-mechanical characterization of materials which demand in-situ measurements or allow very limited sampling. Moreover, both techniques have been used, for the first time, to map the distribution of salts in building stone in the laboratory; micro-drilling was also applied in the same context in-situ. The results of the laboratory tests performed on limestone impregnated with sodium and magnesium sulfate confirm that both the scratch tool and the DRMS may successfully detect the location of the salt front, as they respond to pore clogging by salt crystals by providing increased scratching/drilling resistance values. Drilling and scratching of duplicate samples treated with a hydrophobic product show the sensitivity of both techniques as they clearly detect changes to the salt front location (i.e. cryptoflorescence) caused by surface treatments. Both techniques were also successful in highlighting the difference in the crystallisation location and pattern of magnesium sulphate and sodium chloride. In-situ application of the micro-drilling test demonstrated its potential for use in the assessment of masonry salt weathering; the results suggest that this technique may, in fact, be useful as a preventive measure against salt damage. Last but not least, both aforementioned novel micro-destructive techniques have been used to assess the effectiveness of commercially available consolidants. The results of the scratch tool have also been utilised to develop a tomography image of the samples under test. Scratching tomography may potentially be combined with in-situ micro-drilling tests to evaluate the effectiveness of consolidation treatments applied on monuments and historic buildings.

On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers, Volumes 1, 2

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

Upadhyaya, Belle R.; Hines, J. Wesley; Lu, Baofu

2005-06-03

The overall purpose of this Nuclear Engineering Education Research (NEER) project was to integrate new, innovative, and existing technologies to develop a fault diagnostics and characterization system for nuclear plant steam generators (SG) and heat exchangers (HX). Issues related to system level degradation of SG and HX tubing, including tube fouling, performance under reduced heat transfer area, and the damage caused by stress corrosion cracking, are the important factors that influence overall plant operation, maintenance, and economic viability of nuclear power systems. The research at The University of Tennessee focused on the development of techniques for monitoring process and structuralmore » integrity of steam generators and heat exchangers. The objectives of the project were accomplished by the completion of the following tasks. All the objectives were accomplished during the project period. This report summarizes the research and development activities, results, and accomplishments during June 2001 September 2004. Development and testing of a high-fidelity nodal model of a U-tube steam generator (UTSG) to simulate the effects of fouling and to generate a database representing normal and degraded process conditions. Application of the group method of data handling (GMDH) method for process variable prediction. Development of a laboratory test module to simulate particulate fouling of HX tubes and its effect on overall thermal resistance. Application of the GMDH technique to predict HX fluid temperatures, and to compare with the calculated thermal resistance.Development of a hybrid modeling technique for process diagnosis and its evaluation using laboratory heat exchanger test data. Development and testing of a sensor suite using piezo-electric devices for monitoring structural integrity of both flat plates (beams) and tubing. Experiments were performed in air, and in water with and without bubbly flow. Development of advanced signal processing methods using wavelet transforms and image processing techniques for isolating flaw types. Development and implementation of a new nonlinear and non-stationary signal processing method, called the Hilbert-Huang transform (HHT), for flaw detection and location. This is a more robust and adaptive approach compared to the wavelet transform.Implementation of a moving-window technique in the time domain for detecting and quantifying flaw types in tubular structures. A window zooming technique was also developed for flaw location in tubes. Theoretical study of elastic wave propagation (longitudinal and shear waves) in metallic flat plates and tubing with and without flaws. Simulation of the Lamb wave propagation using the finite-element code ABAQUS. This enabled the verification of the experimental results. The research tasks included both analytical research and experimental studies. The experimental results helped to enhance the robustness of fault monitoring methods and to provide a systematic verification of the analytical results. The results of this research were disseminated in scientific meetings. The journal manuscript titled, "Structural Integrity Monitoring of Steam generator Tubing Using Transient Acoustic Signal Analysis," was published in IEEE Trasactions on Nuclear Science, Vol. 52, No. 1, February 2005. The new findings of this research have potential applications in aerospace and civil structures. The report contains a complete bibliography that was developed during the course of the project.« less

Alternate methodologies to experimentally investigate shock initiation properties of explosives

NASA Astrophysics Data System (ADS)

Svingala, Forrest R.; Lee, Richard J.; Sutherland, Gerrit T.; Benjamin, Richard; Boyle, Vincent; Sickels, William; Thompson, Ronnie; Samuels, Phillip J.; Wrobel, Erik; Cornell, Rodger

2017-01-01

Reactive flow models are desired for new explosive formulations early in the development stage. Traditionally, these models are parameterized by carefully-controlled 1-D shock experiments, including gas-gun testing with embedded gauges and wedge testing with explosive plane wave lenses (PWL). These experiments are easy to interpret due to their 1-D nature, but are expensive to perform and cannot be performed at all explosive test facilities. This work investigates alternative methods to probe shock-initiation behavior of new explosives using widely-available pentolite gap test donors and simple time-of-arrival type diagnostics. These experiments can be performed at a low cost at most explosives testing facilities. This allows experimental data to parameterize reactive flow models to be collected much earlier in the development of an explosive formulation. However, the fundamentally 2-D nature of these tests may increase the modeling burden in parameterizing these models and reduce general applicability. Several variations of the so-called modified gap test were investigated and evaluated for suitability as an alternative to established 1-D gas gun and PWL techniques. At least partial agreement with 1-D test methods was observed for the explosives tested, and future work is planned to scope the applicability and limitations of these experimental techniques.

Develop Advanced Nonlinear Signal Analysis Topographical Mapping System

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi

1997-01-01

During the development of the SSME, a hierarchy of advanced signal analysis techniques for mechanical signature analysis has been developed by NASA and AI Signal Research Inc. (ASRI) to improve the safety and reliability for Space Shuttle operations. These techniques can process and identify intelligent information hidden in a measured signal which is often unidentifiable using conventional signal analysis methods. Currently, due to the highly interactive processing requirements and the volume of dynamic data involved, detailed diagnostic analysis is being performed manually which requires immense man-hours with extensive human interface. To overcome this manual process, NASA implemented this program to develop an Advanced nonlinear signal Analysis Topographical Mapping System (ATMS) to provide automatic/unsupervised engine diagnostic capabilities. The ATMS will utilize a rule-based Clips expert system to supervise a hierarchy of diagnostic signature analysis techniques in the Advanced Signal Analysis Library (ASAL). ASAL will perform automatic signal processing, archiving, and anomaly detection/identification tasks in order to provide an intelligent and fully automated engine diagnostic capability. The ATMS has been successfully developed under this contract. In summary, the program objectives to design, develop, test and conduct performance evaluation for an automated engine diagnostic system have been successfully achieved. Software implementation of the entire ATMS system on MSFC's OISPS computer has been completed. The significance of the ATMS developed under this program is attributed to the fully automated coherence analysis capability for anomaly detection and identification which can greatly enhance the power and reliability of engine diagnostic evaluation. The results have demonstrated that ATMS can significantly save time and man-hours in performing engine test/flight data analysis and performance evaluation of large volumes of dynamic test data.

Development of at-wavelength metrology for x-ray optics at the ALS

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

Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Yuan, Sheng

2010-07-09

The comprehensive realization of the exciting advantages of new third- and forth-generation synchrotron radiation light sources requires concomitant development of reflecting and diffractive x-ray optics capable of micro- and nano-focusing, brightness preservation, and super high resolution. The fabrication, tuning, and alignment of the optics are impossible without adequate metrology instrumentation, methods, and techniques. While the accuracy of ex situ optical metrology at the Advanced Light Source (ALS) has reached a state-of-the-art level, wavefront control on beamlines is often limited by environmental and systematic alignment factors, and inadequate in situ feedback. At ALS beamline 5.3.1, we are developing broadly applicable, high-accuracy,more » in situ, at-wavelength wavefront measurement techniques to surpass 100-nrad slope measurement accuracy for Kirkpatrick-Baez (KB) mirrors. The at-wavelength methodology we are developing relies on a series of tests with increasing accuracy and sensitivity. Geometric Hartmann tests, performed with a scanning illuminated sub-aperture determine the wavefront slope across the full mirror aperture. Shearing interferometry techniques use coherent illumination and provide higher sensitivity wavefront measurements. Combining these techniques with high precision optical metrology and experimental methods will enable us to provide in situ setting and alignment of bendable x-ray optics to realize diffraction-limited, sub 50 nm focusing at beamlines. We describe here details of the metrology beamline endstation, the x-ray beam diagnostic system, and original experimental techniques that have already allowed us to precisely set a bendable KB mirror to achieve a focused spot size of 150 nm.« less

Potential Biomarkers and Their Applications for Rapid and Reliable Detection of Malaria

PubMed Central

Jain, Priyamvada; Chakma, Babina; Patra, Sanjukta; Goswami, Pranab

2014-01-01

Malaria has been responsible for the highest mortality in most malaria endemic countries. Even after decades of malaria control campaigns, it still persists as a disease of high mortality due to improper diagnosis and rapidly evolving drug resistant malarial parasites. For efficient and economical malaria management, WHO recommends that all malaria suspected patients should receive proper diagnosis before administering drugs. It is thus imperative to develop fast, economical, and accurate techniques for diagnosis of malaria. In this regard an in-depth knowledge on malaria biomarkers is important to identify an appropriate biorecognition element and utilize it prudently to develop a reliable detection technique for diagnosis of the disease. Among the various biomarkers, plasmodial lactate dehydrogenase and histidine-rich protein II (HRP II) have received increasing attention for developing rapid and reliable detection techniques for malaria. The widely used rapid detection tests (RDTs) for malaria succumb to many drawbacks which promotes exploration of more efficient economical detection techniques. This paper provides an overview on the current status of malaria biomarkers, along with their potential utilization for developing different malaria diagnostic techniques and advanced biosensors. PMID:24804253

Computer assisted analysis of auroral images obtained from high altitude polar satellites

NASA Technical Reports Server (NTRS)

Samadani, Ramin; Flynn, Michael

1993-01-01

Automatic techniques that allow the extraction of physically significant parameters from auroral images were developed. This allows the processing of a much larger number of images than is currently possible with manual techniques. Our techniques were applied to diverse auroral image datasets. These results were made available to geophysicists at NASA and at universities in the form of a software system that performs the analysis. After some feedback from users, an upgraded system was transferred to NASA and to two universities. The feasibility of user-trained search and retrieval of large amounts of data using our automatically derived parameter indices was demonstrated. Techniques based on classification and regression trees (CART) were developed and applied to broaden the types of images to which the automated search and retrieval may be applied. Our techniques were tested with DE-1 auroral images.

A collection of articles on S/X-band experiment zero delay ranging tests, volume 1

NASA Technical Reports Server (NTRS)

Otoshi, T. Y. (Editor)

1975-01-01

Articles are presented which are concerned with the development of special test equipment and a dual-frequency zero delay device (ZDD) that were required for range tests and the measurement of ground station delays for the Mariner-Venus-Mercury 1973 S/X-band experiment. Test data obtained at DSS 14 after installation of the ZDD on the 64-m antenna are given. It is shown that large variations of range were observed as a function of antenna elevation angle and were sensitive to antenna location. A ranging calibration configuration that was subsequently developed and a technique for determining the appropriate Z-correction are described. Zero delay test data at DSS 14 during the Mariner 10 Venus-Mercury-Encounter periods (1974 days 12-150) are presented. The theoretical analysis and experimental verifications are included of the effects of multipath and effects of discontinuities on range delay measurements. A movable subreflector technique and the multipath theory were used to isolate principal multipath errors on the 64-m antenna and to enable a more accurate determination of the actual ground station range delay.

Comparative transition performance of several nosetip materials as defined by ballistics-range testing

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

Reda, D.C.

1979-01-01

Requirements and techniques for conducting aerothermodynamic tests of reentry body nosetips/materials in hypersonic ballistics-range environments (ISA 22nd IIS), and associated data interpretation/analyses methods using interactive graphics (ISA 24th IIS) have been outlined. Such testing, which centers on the utilization of electro-optical pyrometry for the measurement of nosetip surface temperature distributions, has provided both the aerothermodynamics and materials-development communities with valuable new capabilities. From an aerothermodynamics standpoint, experimental results serve to test the validity of existing computer codes/correlations, as well as to expand the data base necessary for the generation of improved predictive techniques. From a materials-development standpoint, results serve tomore » define relationships between fabrication/processing methods and associated material thermal response as well as to provide for relative ranking of candidate materials under controlled reentry conditions. Following these multipurpose objectives, ballistic-range tests of preablated graphite and carbon/carbon composite nosetips have been conducted. Results are presented herein which illustrate the comparative transition performance of five nosetip materials from both mean and statistical (degree-of-asymmetry) viewpoints.« less

Social marketing techniques for public health communication: a review of syphilis awareness campaigns in 8 US cities.

PubMed

Vega, Miriam Y; Roland, Eric L

2005-10-01

To describe the social marketing approaches used to increase syphilis awareness in 8 US cities. We reviewed the typical academic approach for developing social marketing campaigns and interviewed health department staff responsible for social marketing campaigns in each city. Using social marketing techniques such as target segmentation, concept testing of materials, and formative evaluation, campaign planners throughout the 8 cities developed a variety of approaches to reach their target audiences. Preliminary results suggest 71% to 80% of men who have sex with men interviewed were aware of the campaigns, and 45% to 53% of them reported they were tested due to the campaigns. Campaigns should address the local epidemic and target audience with culturally appropriate messages.

Stereo vision techniques for telescience

NASA Astrophysics Data System (ADS)

Hewett, S.

1990-02-01

The Botanic Experiment is one of the pilot experiments in the Telescience Test Bed program at the ESTEC research and technology center of the European Space Agency. The aim of the Telescience Test Bed is to develop the techniques required by an experimenter using a ground based work station for remote control, monitoring, and modification of an experiment operating on a space platform. The purpose of the Botanic Experiment is to examine the growth of seedlings under various illumination conditions with a video camera from a number of viewpoints throughout the duration of the experiment. This paper describes the Botanic Experiment and the points addressed in developing a stereo vision software package to extract quantitative information about the seedlings from the recorded video images.

Software engineering techniques and CASE tools in RD13

NASA Astrophysics Data System (ADS)

Buono, S.; Gaponenko, I.; Jones, R.; Khodabandeh, A.; Mapelli, L.; Mornacchi, G.; Prigent, D.; Sanchez-Corral, E.; Skiadelli, M.; Toppers, A.; Duval, P. Y.; Ferrato, D.; Le Van Suu, A.; Qian, Z.; Rondot, C.; Ambrosini, G.; Fumagalli, G.; Polesello, G.; Aguer, M.; Huet, M.

1994-12-01

The RD13 project was approved in April 1991 for the development of a scalable data-taking system suitable for hosting various LHC studies. One of its goals is the exploitation of software engineering techniques, in order to indicate their overall suitability for data acquisition (DAQ), software design and implementation. This paper describes how such techniques have been applied to the development of components of the RD13 DAQ used in test-beam runs at CERN. We describe our experience with the Artifex CASE tool and its associated methodology. The issues raised when code generated by a CASE tool has to be integrated into an existing environment are also discussed.

A Real-Time High Performance Data Compression Technique For Space Applications

NASA Technical Reports Server (NTRS)

Yeh, Pen-Shu; Venbrux, Jack; Bhatia, Prakash; Miller, Warner H.

2000-01-01

A high performance lossy data compression technique is currently being developed for space science applications under the requirement of high-speed push-broom scanning. The technique is also error-resilient in that error propagation is contained within a few scan lines. The algorithm is based on block-transform combined with bit-plane encoding; this combination results in an embedded bit string with exactly the desirable compression rate. The lossy coder is described. The compression scheme performs well on a suite of test images typical of images from spacecraft instruments. Hardware implementations are in development; a functional chip set is expected by the end of 2001.

Development and evaluation of vision rehabilitation devices.

PubMed

Luo, Gang; Peli, Eli

2011-01-01

We have developed a range of vision rehabilitation devices and techniques for people with impaired vision due to either central vision loss or severely restricted peripheral visual field. We have conducted evaluation studies with patients to test the utilities of these techniques in an effort to document their advantages as well as their limitations. Here we describe our work on a visual field expander based on a head mounted display (HMD) for tunnel vision, a vision enhancement device for central vision loss, and a frequency domain JPEG/MPEG based image enhancement technique. All the evaluation studies included visual search paradigms that are suitable for conducting indoor controllable experiments.

An ultrasonic technique for measuring stress in fasteners

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

Stevens, K. J.; Day, P.; Byron, D.

1999-12-02

High temperature bolting alloys are extensively used in the thermal power generation industry as for example, reheat ESV and Governor valve studs. Remnant life assessment methodologies and plant maintenance procedures require the monitoring of the operational stress levels in these fasteners. Some conventional ultrasonic techniques require longitudinal wave measurements to be undertaken when the nut on the bolt is loosened and then re-tightened. Other techniques use a combination of shear waves and longitudinal waves. In this paper, the problems and pitfalls associated with various ultrasonic techniques for measuring stress in bolts, is discussed. An ultrasonic technique developed for measuring themore » stress in Durehete 1055 bolts is presented. Material from a textured rolled bar has been used as a test bed in the development work. The technique uses shear wave birefringence and compression waves at several frequencies to measure texture, fastener length and the average stress. The technique was developed by making ultrasonic measurements on bolts tensioned in universal testing machines and a hydraulic nut. The ultrasonic measurements of residual stress have been checked against strain gauge measurements. The Durehete bolts have a hollow cylinder geometry of restricted dimensions, which significantly alters compression and shear wave velocities from bulk values and introduces hoop stresses which can be measured by rotating the polarization of the shear wave probe. Modelling of the experimental results has been undertaken using theories for the elastic wave propagation through waveguides. The dispersion equations allow the velocity and length of the fastener to be measured ultrasonically in some situations where the length of the fastener can not be measured directly with a vernier caliper or micrometer and/or where it is undesirable to loosen nuts to take calibration readings of the shear and compression wave velocities.« less

DEVELOPMENT AND EVALUATION OF IN VITRO IMAGING TECHNIQUES USED TO SCREEN AGENTS THAT AFFECT NEURONAL DIFFERENTIATION.

EPA Science Inventory

Testing chemicals for potential developmental neurotoxicity is an issue of regulatory concern. Developmental vulnerability is determined by pharmacokinetic and pharmacodynamic differences between developing and adult animals. These pharmacokinetic and pharmacodynamic factors dete...

Advanced technology airfoil research, volume 2. [conferences

NASA Technical Reports Server (NTRS)

1979-01-01

A comprehensive review of airfoil research is presented. The major thrust of the research is in three areas: development of computational aerodynamic codes for airfoil analysis and design, development of experimental facilities and test techniques, and all types of airfoil applications.

Quiet engine program: Turbine noise suppression. -Volume 1: General treatment evaluation and measurement techniques

NASA Technical Reports Server (NTRS)

Clemons, A.; Hehmann, H.; Radecki, K.

1973-01-01

Acoustic treatment was developed for jet engine turbine noise suppression. Acoustic impedance and duct transmission loss measurements were made for various suppression systems. An environmental compatibility study on several material types having suppression characteristics is presented. Two sets of engine hardware were designed and are described along with engine test results which include probe, farfield, near field, and acoustic directional array data. Comparisons of the expected and the measured suppression levels are given as well as a discussion of test results and design techniques.

Feasibility Study for Implementing Magnetic Suspension in the Glenn Research Center 225 cm2 Supersonic Wind Tunnel for Testing the Dynamic Stability of Blunt Bodies

NASA Technical Reports Server (NTRS)

Sevier, Abigail; Davis, David O.; Schoenenberger, Mark; Barnhart, Paul

2016-01-01

The implementation of a magnetic suspension system in the NASA Glenn Research Center (GRC) 225 cm2 Supersonic Wind Tunnel would be a powerful test technique that could accurately determine the dynamic stability of blunt body entry vehicles with no sting interference. This paper explores initial design challenges to be evaluated before implementation, including defining the lowest possible operating dynamic pressure and corresponding model size, developing a compatible video analysis technique, and incorporating a retractable initial support sting.

AGARD Flight Test Instrumentation Series. Volume 1, Issue 2. Basic Principles of Flight Test Instrumentation Engineering (Introduction Generale aux Principles de Base de l’Instrumentation des Essais en Vol)

DTIC Science & Technology

1994-03-01

evaluation of its anticipated value. If the program can be accomplished using conventional techniques , this should be seriously considered. Development or...the direct frequency generating principles such as, pulse tachos, turbine flowmeters, and encoders, also Doppler and laser techniques used for...CERAMIC BLOCK Figure 5.3. The basic concepts of the laser ring gyro (LRG). The principle depends upon the guidance of two beams of laser light around an