Coil tubing fishing operations utilize a first time technique to strip over and recover 9500 feet of stuck slickline wire

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

Forgenie, V.H.; Heiberger, E.M.; Kelso, L.K.

1995-12-31

Coil tubing was utilized to perform a modified strip over operation and recover 9500 ft. of stuck slickline (0.108 in.) wire. The technique, thought to be an industry first, eliminated the risky option of recovering the wire piecemeal via conventional wireline fishing operations. This paper documents the background that lead to the development of the technique. An operational summary details its implementation and illustrations are included of the special tools and techniques employed.

Simulation of wind turbine wakes using the actuator line technique

PubMed Central

Sørensen, Jens N.; Mikkelsen, Robert F.; Henningson, Dan S.; Ivanell, Stefan; Sarmast, Sasan; Andersen, Søren J.

2015-01-01

The actuator line technique was introduced as a numerical tool to be employed in combination with large eddy simulations to enable the study of wakes and wake interaction in wind farms. The technique is today largely used for studying basic features of wakes as well as for making performance predictions of wind farms. In this paper, we give a short introduction to the wake problem and the actuator line methodology and present a study in which the technique is employed to determine the near-wake properties of wind turbines. The presented results include a comparison of experimental results of the wake characteristics of the flow around a three-bladed model wind turbine, the development of a simple analytical formula for determining the near-wake length behind a wind turbine and a detailed investigation of wake structures based on proper orthogonal decomposition analysis of numerically generated snapshots of the wake. PMID:25583862

Seasonal changes in the techniques employed by wild chimpanzees in the Mahale Mountains, Tanzania, to feed on termites (Pseudacanthotermes spiniger).

PubMed

Uehara, S

1982-01-01

During a short period, wild chimpanzees of group K in the Mahale Mountains employ a set of several techniques, including tool use, to feed on one species of termite (Pseudacanthotermes spiniger). They appear to use each technique appropriately according to phenological changes in the prey insect's activities. The chimpanzees also ingest small pieces of soil from the tower of P. spiniger's mound throughout the year. Geophagy presumably makes them visually and tactually aware of the phenological changes of the termite's reproductive cycle. Analyses of fecal samples from the chimpanzees indicate interannual fluctuations in the amount of termites ingested. On the other hand, the chimpanzees of group B, ranging to the north of group K, utilize a fishing technique to obtain another type of termite (Macrotermes?herus) on a large scale during the first half of the wet season. Fecal analysis data show that chimpanzees of group B consume far more termites than those of group K. The probability that the same or similar tool-using techniques as fishing may be employed in feeding on different types of insects by chimpanzees of different unit groups according to subtle local differences in the insect fauna of their home ranges is discussed.

INVESTIGATION OF THE USE OF STATISTICS IN COUNSELING STUDENTS.

ERIC Educational Resources Information Center

HEWES, ROBERT F.

THE OBJECTIVE WAS TO EMPLOY TECHNIQUES OF PROFILE ANALYSIS TO DEVELOP THE JOINT PROBABILITY OF SELECTING A SUITABLE SUBJECT MAJOR AND OF ASSURING TO A HIGH DEGREE GRADUATION FROM COLLEGE WITH THAT MAJOR. THE SAMPLE INCLUDED 1,197 MIT FRESHMEN STUDENTS IN 1952-53, AND THE VALIDATION GROUP INCLUDED 699 ENTRANTS IN 1954. DATA INCLUDED SECONDARY…

Investigation of Antiangiogenic Mechanisms Using Novel Imaging Techniques

DTIC Science & Technology

2010-02-01

of the tumor environment can sensitize the tumor to conventional cytotoxic therapies. To this end, we employ the window chamber model to optically ...facilitate longitudinal, in vivo investigation into the parameters of interest. These include Doppler Optical Coherence Tomography for the measurement of... Optical Techniques, Tumor Pathophysiology, Treatment Response, Vascular Normalization 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18

Chromosome Analysis

NASA Technical Reports Server (NTRS)

1998-01-01

Perceptive Scientific Instruments, Inc., provides the foundation for the Powergene line of chromosome analysis and molecular genetic instrumentation. This product employs image processing technology from NASA's Jet Propulsion Laboratory and image enhancement techniques from Johnson Space Center. Originally developed to send pictures back to earth from space probes, digital imaging techniques have been developed and refined for use in a variety of medical applications, including diagnosis of disease.

Reduction of polyatomic interferences in ICP-MS by collision/reaction cell (CRC-ICP-MS) techniques

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

Eiden, Greg C; Barinaga, Charles J; Koppenaal, David W

2012-05-01

Polyatomic and other spectral interferences in plasma source mass spectrometry (PSMS) can be dramatically reduced using collision and reaction cells (CRC). These devices have been used for decades in fundamental studies of ion-molecule chemistry, but have only recently been applied to PSMS. Benefits of this approach as applied in inductively coupled plasma MS (ICP-MS) include interference reduction, isobar separation, and thermalization/focusing of ions. Novel ion-molecule chemistry schemes are now routinely designed and empirically evaluated with relative ease. These “chemical resolution” techniques can avert interferences requiring mass spectral resolutions of >600,000 (m/m). Purely physical ion beam processes, including collisional dampening andmore » collisional dissociation, are also employed to provide improved sensitivity, resolution, and spectral simplicity. CRC techniques are now firmly entrenched in current-day ICP-MS technology, enabling unprecedented flexibility and freedom from many spectral interferences. A significant body of applications has now been reported in the literature. CRC techniques are found to be most useful for specialized or difficult analytical needs and situations, and are employed in both single- and multi-element determination modes.« less

A framework for the design and development of physical employment tests and standards.

PubMed

Payne, W; Harvey, J

2010-07-01

Because operational tasks in the uniformed services (military, police, fire and emergency services) are physically demanding and incur the risk of injury, employment policy in these services is usually competency based and predicated on objective physical employment standards (PESs) based on physical employment tests (PETs). In this paper, a comprehensive framework for the design of PETs and PESs is presented. Three broad approaches to physical employment testing are described and compared: generic predictive testing; task-related predictive testing; task simulation testing. Techniques for the selection of a set of tests with good coverage of job requirements, including job task analysis, physical demands analysis and correlation analysis, are discussed. Regarding individual PETs, theoretical considerations including measurability, discriminating power, reliability and validity, and practical considerations, including development of protocols, resource requirements, administrative issues and safety, are considered. With regard to the setting of PESs, criterion referencing and norm referencing are discussed. STATEMENT OF RELEVANCE: This paper presents an integrated and coherent framework for the development of PESs and hence provides a much needed theoretically based but practically oriented guide for organisations seeking to establish valid and defensible PESs.

Who wrote the "Letter to the Hebrews"?: data mining for detection of text authorship

NASA Astrophysics Data System (ADS)

Sabordo, Madeleine; Chai, Shong Y.; Berryman, Matthew J.; Abbott, Derek

2005-02-01

This paper explores the authorship of the Letter to the Hebrews using a number of different measures of relationship between different texts of the New Testament. The methods used in the study include file zipping and compression techniques, prediction by the partial matching technique and the word recurrence interval technique. The long term motivation is that the techniques employed in this study may find applicability in future generation web search engines, email authorship identification, detection of plagiarism and terrorist email traffic filtration.

Update: Biochemistry of Genetic Manipulation.

ERIC Educational Resources Information Center

Barker, G. R.

1983-01-01

Various topics on the biochemistry of genetic manipulation are discussed. These include genetic transformation and DNA; genetic expression; DNA replication, repair, and mutation; technology of genetic manipulation; and applications of genetic manipulation. Other techniques employed are also considered. (JN)

A Behaviorally-Oriented Activities Therapy Program for Adolescents.

ERIC Educational Resources Information Center

Chasanoff, Enid; Schrader, Carl

1979-01-01

A behaviorally-oriented activities therapy program was designed and implemented with adolescents who manifested problems at school, at home, and with peers. Techniques employed included: contingency contracting, assertiveness training, relaxation training, and cognitive restructuring. (Author/KC)

Method for Fabricating Composite Structures Using Pultrusion Processing

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

2000-01-01

A method for fabricating composite structures at a low-cost, moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a net-shape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

Method for Fabricating Composite Structures Using Continuous Press Forming

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1997-01-01

A method for fabricating composite structures at a low-cost. moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a net-shape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates. resulting in lower cost and high structural performance.

Method for Fabricating Composite Structures Using Pultrusion Processing

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

2000-01-01

A method for fabricating composite structures at a low-cost, moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a netshape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electronbeam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

Avoiding Complications in Bone and Soft Tissue Ablation

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

Kurup, A. Nicholas, E-mail: kurup.anil@mayo.edu; Schmit, Grant D., E-mail: schmit.grant@mayo.edu; Morris, Jonathan M., E-mail: morris.jonathan@mayo.edu

As with percutaneous ablation of tumors in the liver, lungs, and kidneys, ablation of bone and non-visceral soft tissue tumors carries risk, primarily from collateral damage to vital structures in proximity to the target tumor. Certain risks are of particular interest when ablating bone and non-visceral soft tissue tumors, namely neural or skin injury, bowel injury, fracture, and gas embolism from damaged applicators. Ablation of large volume tumors also carries special risk. Many techniques may be employed by the interventional radiologist to minimize complications when treating tumors in the musculoskeletal system. These methods include those to depict, displace, or monitormore » critical structures. Thus, measures to provide thermoprotection may be active, such as careful ablation applicator placement and use of various displacement techniques, as well as passive, including employment of direct temperature, radiographic, or neurophysiologic monitoring techniques. Cementoplasty should be considered in certain skeletal locations at risk of fracture. Patients treated with large volume tumors should be monitored for renal dysfunction and properly hydrated. Finally, ablation applicators should be cautiously placed in the constrained environment of intact bone.« less

Surface and Flow Field Measurements on the FAITH Hill Model

NASA Technical Reports Server (NTRS)

Bell, James H.; Heineck, James T.; Zilliac, Gregory; Mehta, Rabindra D.; Long, Kurtis R.

2012-01-01

A series of experimental tests, using both qualitative and quantitative techniques, were conducted to characterize both surface and off-surface flow characteristics of an axisymmetric, modified-cosine-shaped, wall-mounted hill named "FAITH" (Fundamental Aero Investigates The Hill). Two separate models were employed: a 6" high, 18" base diameter machined aluminum model that was used for wind tunnel tests and a smaller scale (2" high, 6" base diameter) sintered nylon version that was used in the water channel facility. Wind tunnel and water channel tests were conducted at mean test section speeds of 165 fps (Reynolds Number based on height = 500,000) and 0.1 fps (Reynolds Number of 1000), respectively. The ratio of model height to boundary later height was approximately 3 for both tests. Qualitative techniques that were employed to characterize the complex flow included surface oil flow visualization for the wind tunnel tests, and dye injection for the water channel tests. Quantitative techniques that were employed to characterize the flow included Cobra Probe to determine point-wise steady and unsteady 3D velocities, Particle Image Velocimetry (PIV) to determine 3D velocities and turbulence statistics along specified planes, Pressure Sensitive Paint (PSP) to determine mean surface pressures, and Fringe Imaging Skin Friction (FISF) to determine surface skin friction (magnitude and direction). This initial report summarizes the experimental set-up, techniques used, data acquired and describes some details of the dataset that is being constructed for use by other researchers, especially the CFD community. Subsequent reports will discuss the data and their interpretation in more detail

Formulation procedure and spectral data for a coatings system optimally employing the high intrinsic reflectance of barium sulphate

NASA Technical Reports Server (NTRS)

Schutt, J. B.; Stromberg, E.; Shai, C. M.; Arens, J. F.

1972-01-01

The use of polyvinyl alcohol as a binder for barium sulphate does not allow the intrinsically high reflectance of this material in the near vacuum ultraviolet to be optimally employed. In an effort to better utilize this property, completely inorganic coatings systems are described, where from the intrinsically high reflectance of barium sulphate in this spectral region can be gotten. Potassium sulphate turns out to be the preferred binder. Compositions, formulating procedures, and application techniques are included. For completeness, absolute and relative reflectance data are included for intra- and intersystem comparisons.

Apollo experience report: Flight anomaly resolution

NASA Technical Reports Server (NTRS)

Lobb, J. D.

1975-01-01

The identification of flight anomalies, the determination of their causes, and the approaches taken for corrective action are described. Interrelationships of the broad range of disciplines involved with the complex systems and the team concept employed to ensure timely and accurate resolution of anomalies are discussed. The documentation techniques and the techniques for management of anomaly resolution are included. Examples of specific anomalies are presented in the original form of their progressive documentation. Flight anomaly resolution functioned as a part of the real-time mission support and postflight testing, and results were included in the postflight documentation.

Simulation of wind turbine wakes using the actuator line technique.

PubMed

Sørensen, Jens N; Mikkelsen, Robert F; Henningson, Dan S; Ivanell, Stefan; Sarmast, Sasan; Andersen, Søren J

2015-02-28

The actuator line technique was introduced as a numerical tool to be employed in combination with large eddy simulations to enable the study of wakes and wake interaction in wind farms. The technique is today largely used for studying basic features of wakes as well as for making performance predictions of wind farms. In this paper, we give a short introduction to the wake problem and the actuator line methodology and present a study in which the technique is employed to determine the near-wake properties of wind turbines. The presented results include a comparison of experimental results of the wake characteristics of the flow around a three-bladed model wind turbine, the development of a simple analytical formula for determining the near-wake length behind a wind turbine and a detailed investigation of wake structures based on proper orthogonal decomposition analysis of numerically generated snapshots of the wake. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Least squares polynomial chaos expansion: A review of sampling strategies

NASA Astrophysics Data System (ADS)

Hadigol, Mohammad; Doostan, Alireza

2018-04-01

As non-institutive polynomial chaos expansion (PCE) techniques have gained growing popularity among researchers, we here provide a comprehensive review of major sampling strategies for the least squares based PCE. Traditional sampling methods, such as Monte Carlo, Latin hypercube, quasi-Monte Carlo, optimal design of experiments (ODE), Gaussian quadratures, as well as more recent techniques, such as coherence-optimal and randomized quadratures are discussed. We also propose a hybrid sampling method, dubbed alphabetic-coherence-optimal, that employs the so-called alphabetic optimality criteria used in the context of ODE in conjunction with coherence-optimal samples. A comparison between the empirical performance of the selected sampling methods applied to three numerical examples, including high-order PCE's, high-dimensional problems, and low oversampling ratios, is presented to provide a road map for practitioners seeking the most suitable sampling technique for a problem at hand. We observed that the alphabetic-coherence-optimal technique outperforms other sampling methods, specially when high-order ODE are employed and/or the oversampling ratio is low.

Telecommunications network optimization

NASA Technical Reports Server (NTRS)

Lee, J.

1979-01-01

Analysis discusses STACOM (state criminal justic communication) network topology program used to design and evaluate digital telecommunications networks STACOM employs ESAU-WILLIAMS technique to search for direct links between system terminations and regional switching center. Inputs include traffic data, terminal locations, and functional requirements.

Assertion: A Technique for Handling Troublesome Library Patrons.

ERIC Educational Resources Information Center

Groark, James J.

1979-01-01

Encourages the use of assertion training for librarians to aid them in providing reference service, interviewing for employment, and handling difficult patrons. A list of references and a selection of readers' comments on the article is included. (FM)

Producing Quality Water for Industrial Use.

ERIC Educational Resources Information Center

Schaezler, Donald J.

1978-01-01

This article discusses the quality of water demanded by industrial plants and the techniques which are currently employed to achieve them. Both quality and quantity requirements are considered including total plant operation, physical and chemical operating controls, and systems monitoring. (CS)

Site 765: Sedimentology

USGS Publications Warehouse

,

1990-01-01

Various techniques were used to decipher the sedimentation history of Site 765, including Markov chain analysis of facies transitions, XRD analysis of clay and other minerals, and multivariate analysis of smear-slide data, in addition to the standard descriptive procedures employed by the shipboard sedimentologist. This chapter presents brief summaries of methodology and major findings of these three techniques, a summary of the sedimentation history, and a discussion of trends in sedimentation through time.

Full-color large-scaled computer-generated holograms for physical and non-physical objects

NASA Astrophysics Data System (ADS)

Matsushima, Kyoji; Tsuchiyama, Yasuhiro; Sonobe, Noriaki; Masuji, Shoya; Yamaguchi, Masahiro; Sakamoto, Yuji

2017-05-01

Several full-color high-definition CGHs are created for reconstructing 3D scenes including real-existing physical objects. The field of the physical objects are generated or captured by employing three techniques; 3D scanner, synthetic aperture digital holography, and multi-viewpoint images. Full-color reconstruction of high-definition CGHs is realized by RGB color filters. The optical reconstructions are presented for verifying these techniques.

SEP thrust subsystem performance sensitivity analysis

NASA Technical Reports Server (NTRS)

Atkins, K. L.; Sauer, C. G., Jr.; Kerrisk, D. J.

1973-01-01

This is a two-part report on solar electric propulsion (SEP) performance sensitivity analysis. The first part describes the preliminary analysis of the SEP thrust system performance for an Encke rendezvous mission. A detailed description of thrust subsystem hardware tolerances on mission performance is included together with nominal spacecraft parameters based on these tolerances. The second part describes the method of analysis and graphical techniques used in generating the data for Part 1. Included is a description of both the trajectory program used and the additional software developed for this analysis. Part 2 also includes a comprehensive description of the use of the graphical techniques employed in this performance analysis.

Management Styles and Techniques: People.

ERIC Educational Resources Information Center

DeLoach, Marva L.; And Others

1987-01-01

Three articles discuss management of library technical processes personnel. The first article focuses on the employer employee relationship and communication; the second explores management trends, including participative decision making, personnel evaluation, management by objectives, and the collegial system; and the third focuses on the…

78 FR 70026 - Proposed Agency Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-22

..., including through the use of automated collection techniques or other forms of information technology. The... Technologies Office (VTO) has developed a voluntary initiative, the EV Everywhere Workplace Charging Challenge... specific success stories, lessons learned, and best practices employers have deployed, thereby increasing...

Method for Fabricating Composite Structures Including Continuous Press Forming and Pultrusion Processing

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1995-01-01

A method for fabricating composite structures at a low-cost, moderate-to-high production rate is disclosed. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply, and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform, and debulking the partially debulked preform to form a netshape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length, and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

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

Love, S.P.; Goff, F.; Counce, D.

Volcanic gases provide important insights on the internal workings of volcanoes and changes in their composition and total flux can warn of impending changes in a volcano`s eruptive state. In addition, volcanoes are important contributors to the earth`s atmosphere, and understanding this volcanic contribution is crucial for unraveling the effect of anthropogenic gases on the global climate. Studies of volcanic gases have long relied upon direct in situ sampling, which requires volcanologists to work on-site within a volcanic crater. In recent years, spectroscopic techniques have increasingly been employed to obtain information on volcanic gases from greater distances and thus atmore » reduced risk. These techniques have included UV correlation spectroscopy (Cospec) for SO{sub 2} monitoring, the most widely-used technique, and infrared spectroscopy in a variety of configurations, both open- and closed-path. Francis et al. have demonstrated good results using the sun as the IR source. This solar occultation technique is quite useful, but puts rather strong restrictions on the location of instrument and is thus best suited to more accessible volcanoes. In order to maximize the flexibility and range of FTIR measurements at volcanoes, work over the last few years has emphasized techniques which utilize the strong radiance contrast between the volcanic gas plume and the sky. The authors have successfully employed these techniques at several volcanoes, including the White Island and Ruapehu volcanoes in New Zealand, the Kilauea volcano on Hawaii, and Mt. Etna in Italy. But Popocatepetl (5452 m), the recently re-awakened volcano 70 km southeast of downtown Mexico City, has provided perhaps the best examples to date of the usefulness of these techniques.« less

Fabrication and Operation of Paper-Based Analytical Devices

NASA Astrophysics Data System (ADS)

Jiang, Xiao; Fan, Z. Hugh

2016-06-01

This review focuses on the fabrication techniques and operational components of microfluidic paper-based analytical devices (μPADs). Being low-cost, user-friendly, fast, and simple, μPADs have seen explosive growth in the literature in the last decade. Many different materials and technologies have been employed to fabricate μPADs for various applications, including those that employ patterning, the creation of physical boundaries, and three-dimensional structures. In addition to fabrication techniques, flow control and other operational components in μPADs are of great interest. These components enable μPADs to control flow rates, direct flow paths via valves, sequentially deliver reagents automatically, and display test results, all of which will make μPADs more suitable for point-of-care applications.

Hidden explosives detector employing pulsed neutron and x-ray interrogation

DOEpatents

Schultz, F.J.; Caldwell, J.T.

1993-04-06

Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

Hidden explosives detector employing pulsed neutron and x-ray interrogation

DOEpatents

Schultz, Frederick J.; Caldwell, John T.

1993-01-01

Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

Multi-carrier mobile TDMA system with active array antenna

NASA Technical Reports Server (NTRS)

Suzuki, Ryutaro; Matsumoto, Yasushi; Hamamoto, Naokazu

1990-01-01

A multi-carrier time division multiple access (TDMA) is proposed for the future mobile satellite communications systems that include a multi-satellite system. This TDMA system employs the active array antenna in which the digital beam forming technique is adopted to control the antenna beam direction. The antenna beam forming is carried out at the base band frequency by using the digital signal processing technique. The time division duplex technique is applied for the TDM/TDMA burst format, in order not to overlap transmit and receive timing.

Compound Separation

NASA Technical Reports Server (NTRS)

1981-01-01

Jet Propulsion Laboratory developed a new one-step liquid-liquid extraction technique which cuts processing time, reduces costs and eliminates much of the equipment required. Technique employs disposable extraction columns, originally developed as an aid to the Los Angeles Police Department, which allow more rapid detection of drugs as part of the department's drug abuse program. Applications include medical treatment, pharmaceutical preparation and forensic chemistry. NASA waived title to Caltech, and Analytichem International is producing Extubes under Caltech license.

Review of Telemicrobiology

PubMed Central

Rhoads, Daniel D.; Mathison, Blaine A.; Bishop, Henry S.; da Silva, Alexandre J.; Pantanowitz, Liron

2016-01-01

Context Microbiology laboratories are continually pursuing means to improve quality, rapidity, and efficiency of specimen analysis in the face of limited resources. One means by which to achieve these improvements is through the remote analysis of digital images. Telemicrobiology enables the remote interpretation of images of microbiology specimens. To date, the practice of clinical telemicrobiology has not been thoroughly reviewed. Objective Identify the various methods that can be employed for telemicrobiology, including emerging technologies that may provide value to the clinical laboratory. Data Sources Peer-reviewed literature, conference proceedings, meeting presentations, and expert opinions pertaining to telemicrobiology have been evaluated. Results A number of modalities have been employed for telemicroscopy including static capture techniques, whole slide imaging, video telemicroscopy, mobile devices, and hybrid systems. Telemicrobiology has been successfully implemented for applications including routine primary diagnois, expert teleconsultation, and proficiency testing. Emerging areas include digital culture plate reading, mobile health applications and computer-augmented analysis of digital images. Conclusions Static image capture techniques to date have been the most widely used modality for telemicrobiology, despite the fact that other newer technologies are available and may produce better quality interpretations. Increased adoption of telemicrobiology offers added value, quality, and efficiency to the clinical microbiology laboratory. PMID:26317376

Welding Curriculum.

ERIC Educational Resources Information Center

EASTCONN Regional Educational Services Center, North Windham, CT.

The purpose of this welding program is to provide students with skills and techniques to become employed as advanced apprentice welders. The welding program manual includes the following sections: (1) course description; (2) general objectives; (3) competencies; (4) curriculum outline for 13 areas; (5) 13 references; and (6) student progress…

Insulated ECG electrodes

NASA Technical Reports Server (NTRS)

Portnoy, W. M.; David, R. M.

1973-01-01

Insulated, capacitively coupled electrode does not require electrolyte paste for attachment. Other features of electrode include wide range of nontoxic material that may be employed for dielectric because of sputtering technique used. Also, electrode size is reduced because there is no need for external compensating networks with FET operational amplifier.

Near-field three-dimensional radar imaging techniques and applications.

PubMed

Sheen, David; McMakin, Douglas; Hall, Thomas

2010-07-01

Three-dimensional radio frequency imaging techniques have been developed for a variety of near-field applications, including radar cross-section imaging, concealed weapon detection, ground penetrating radar imaging, through-barrier imaging, and nondestructive evaluation. These methods employ active radar transceivers that operate at various frequency ranges covering a wide range, from less than 100 MHz to in excess of 350 GHz, with the frequency range customized for each application. Computational wavefront reconstruction imaging techniques have been developed that optimize the resolution and illumination quality of the images. In this paper, rectilinear and cylindrical three-dimensional imaging techniques are described along with several application results.

PROTECT: PRoximal balloon Occlusion TogEther with direCt Thrombus aspiration during stent retriever thrombectomy - evaluation of a double embolic protection approach in endovascular stroke treatment.

PubMed

Maegerlein, Christian; Mönch, Sebastian; Boeckh-Behrens, Tobias; Lehm, Manuel; Hedderich, Dennis M; Berndt, Maria Teresa; Wunderlich, Silke; Zimmer, Claus; Kaesmacher, Johannes; Friedrich, Benjamin

2017-12-08

Stent retriever-based mechanical thrombectomy (MT) for emergent large vessel occlusions (ELVO) is often complicated by thrombus fragmentation causing distal embolization and embolization to new vascular territories. Well-established embolic protection approaches include proximal flow arrest and distal aspiration techniques during stent retriever maneuvers. Aiming at the reduction of thrombus fragmentation during MT we evaluated a technical approach combining proximal balloon occlusion together with direct thrombus aspiration during MT: the PROTECT technique. We performed a case-control study comparing the PROTECT technique with sole distal aspiration during MT regarding technical and procedural parameters, n=200 patients with ELVO of either the terminus of the internal carotid artery or the proximal middle artery were included. PROTECT resulted in a shorter procedure time (29 vs 40 min; P=0.002), in a higher rate of successful recanalizations (100% vs 78%; P=0.001) and a higher rate of complete reperfusions (70% vs 39%; P<0.001) compared with sole distal aspiration during MT. The PROTECT technique is a promising new approach to significantly reduce thrombus fragmentation and, hence distal embolization during MT. This safe and efficient technique needs to be validated in larger trials to confirm our results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

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

C. Priniski, T. Dodson, M. Duco, S. Raftopoulos, R. Ellis, and A. Brooks

In support of the National Compact Stellerator Experiment (NCSX), stellerator assembly activities continued this past year at the Princeton Plasma Physics Laboratory (PPPL) in partnership with the Oak Ridge National Laboratory (ORNL). The construction program saw the completion of the first two Half Field-Period Assemblies (HPA), each consisting of three modular coils. The full machine includes six such sub-assemblies. A single HPA consists of three of the NCSX modular coils wound and assembled at PPPL. These geometrically-complex threedimensional coils were wound using computer-aided metrology and CAD models to tolerances within +/- 0.5mm. The assembly of these coils required similar accuracymore » on a larger scale with the added complexity of more individual parts and fewer degrees of freedom for correction. Several new potential positioning issues developed for which measurement and control techniques were developed. To accomplish this, CAD coordinate-based computer metrology equipment and software similar to the solutions employed for winding the modular coils was used. Given the size of the assemblies, the primary tools were both interferometeraided and Absolute Distance Measurement (ADM)-only based laser trackers. In addition, portable Coordinate Measurement Machine (CMM) arms and some novel indirect measurement techniques were employed. This paper will detail both the use of CAD coordinate-based metrology technology and the techniques developed and employed for dimensional control of NSCX subassemblies. The results achieved and possible improvements to techniques will be discussed.« less

Surface mapping of spike potential fields: experienced EEGers vs. computerized analysis.

PubMed

Koszer, S; Moshé, S L; Legatt, A D; Shinnar, S; Goldensohn, E S

1996-03-01

An EEG epileptiform spike focus recorded with scalp electrodes is clinically localized by visual estimation of the point of maximal voltage and the distribution of its surrounding voltages. We compared such estimated voltage maps, drawn by experienced electroencephalographers (EEGers), with a computerized spline interpolation technique employed in the commercially available software package FOCUS. Twenty-two spikes were recorded from 15 patients during long-term continuous EEG monitoring. Maps of voltage distribution from the 28 electrodes surrounding the points of maximum change in slope (the spike maximum) were constructed by the EEGer. The same points of maximum spike and voltage distributions at the 29 electrodes were mapped by computerized spline interpolation and a comparison between the two methods was made. The findings indicate that the computerized spline mapping techniques employed in FOCUS construct voltage maps with similar maxima and distributions as the maps created by experienced EEGers. The dynamics of spike activity, including correlations, are better visualized using the computerized technique than by manual interpretation alone. Its use as a technique for spike localization is accurate and adds information of potential clinical value.

Electrodeposition for Electrochemical Energy Conversion and Storage Devices

NASA Astrophysics Data System (ADS)

Shaigan, Nima

Electrodeposition of metals, alloys, metal oxides, conductive polymers, and their composites plays a pivotal role in fabrication processes of some recently developed electrochemical energy devices, most particularly fuel cells, supercapacitors, and batteries. Unique nanoscale architectures of electrocatalysts for low temperature fuel cells, including proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC), can only be obtained through electrodeposition processes. Promising, cost-effective conductive/protective coatings for stainless steel interconnects used in solid oxide fuel cells (SOFCs) have been achieved employing a variety of electrodeposition techniques. In supercapacitors, anodic deposition of metal oxides, conductive polymers, and their composites is a versatile technique for fabrication of electrodes with distinctive morphology and exceptional specific capacitance. Electrodeposition is also very recently employed for preparation of Sn-based anodes for lithium ion batteries.

Verification of component mode techniques for flexible multibody systems

NASA Technical Reports Server (NTRS)

Wiens, Gloria J.

1990-01-01

Investigations were conducted in the modeling aspects of flexible multibodies undergoing large angular displacements. Models were to be generated and analyzed through application of computer simulation packages employing the 'component mode synthesis' techniques. Multibody Modeling, Verification and Control Laboratory (MMVC) plan was implemented, which includes running experimental tests on flexible multibody test articles. From these tests, data was to be collected for later correlation and verification of the theoretical results predicted by the modeling and simulation process.

47 CFR 101.111 - Emission limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... using transmissions other than those employing digital modulation techniques: (i) On any frequency removed from the assigned frequency by more than 50 percent up to and including 100 percent of the authorized bandwidth: At least 25 decibels; (ii) On any frequency removed from the assigned frequency by more...

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.

Investigating a Drop-on-Demand Microdispenser for Standardized Sample Preparation

DTIC Science & Technology

2011-09-01

including the printing of photodiodes , polymer and protein arrays , and in electronics manufacturing (4–7). These applications benefit from the wide...photograph of an array of microdroplets demonstrates a more even sample dispersion when sample is dispensed with a DOD microdispenser... threats encountered. A variety of techniques that offer temporary alternatives have been employed, including drop-and-dry (dropcasting) and spray

Radio techniques for probing the terrestrial ionosphere.

NASA Astrophysics Data System (ADS)

Hunsucker, R. D.

The subject of the book is a description of the basic principles of operation, plus the capabilities and limitations of all generic radio techniques employed to investigate the terrestrial ionosphere. The purpose of this book is to present to the reader a balanced treatment of each technique so they can understand how to interpret ionospheric data and decide which techniques are most effective for studying specific phenomena. The first two chapters outline the basic theory underlying the techniques, and each following chapter discusses a separate technique. This monograph is entirely devoted to techniques in aeronomy and space physics. The approach is unique in its presentation of the principles, capabilities and limitations of the most important presently used radio techniques. Typical examples of data are shown for the various techniques, and a brief historical account of the technique development is presented. An extended annotated bibliography of the salient papers in the field is included.

A review of DTCA techniques: Appraising their success and potential impact on medication users.

PubMed

Babar, Zaheer-Ud-Din; Siraj, Ashna Medina; Curley, Louise

2018-03-01

Direct-to-consumer advertising (DTCA) has been present in some countries for nearly two decades. Its success and ramifications have been examined but not yet cataloged recently in a comprehensive manner. To review existing literature studies on the topic of DTCA techniques to provide an analysis of the current methods considered by drug marketers to enhance the effect of pharmaceutical product promotion and its success, as well as examine ramifications on the drug use process. A search of 7 electronic databases including MEDLINE and SCOPUS was conducted in December 2015, and updated until February 2016. A scientific review of literature (2008-2015) was performed to identify and collate information from relevant, peer reviewed original study articles investigating various DTCA techniques commonly employed in pharmaceutical promotion. A thematic analysis was undertaken to categorize categories of drug promotion, or techniques, and the saliency and impact of these. Nineteen original study articles were included in this review. All articles were based in the U.S. and New Zealand, where DTCA is legal. After reviewing all the articles, 4 themes with 11 subcategories were generated. These themes included disease mongering and medicalization, drug references, advertisement strategies and eDTCA. The themes describe different categories of techniques used to augment DTC advertisements to increase their impact and overall success in promoting a pharmaceutical product. Many DTCA techniques utilized by pharmaceutical marketers are beneficial to the success of DTC promotion of a drug. These techniques include the use of drug efficacy information, comparative claims, non-branded help seeking advertisements, formatted risks information, celebrity or expert endorsers and website trust factors. Through their use, public perception of the drug is made more favorable, increased attention is drawn to the advertisement, and the pharmaceutical product gains greater credibility and subsequent success in sales. However some techniques, although beneficial to pharmaceutical promotion, need to be monitored by policymakers and regulatory advisors, as they have the potential to negatively impact consumer health knowledge. Overall, through this review it is evident that there are a number if techniques that employed by pharmaceutical marketers to augment the success of pharmaceutical promotion. While these techniques may be beneficial to pharmaceutical companies and might increase awareness amongst consumers, it is important to be critical of them, as they have the potential to be exploited by pharmaceutical marketers. This review indicated that although some techniques are successful and appear to be satisfactory in providing information to consumers, other techniques need to be appraised more closely. Copyright © 2017 Elsevier Inc. All rights reserved.

Monte Carlo Simulation of Nonlinear Radiation Induced Plasmas. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Wang, B. S.

1972-01-01

A Monte Carlo simulation model for radiation induced plasmas with nonlinear properties due to recombination was, employing a piecewise linearized predict-correct iterative technique. Several important variance reduction techniques were developed and incorporated into the model, including an antithetic variates technique. This approach is especially efficient for plasma systems with inhomogeneous media, multidimensions, and irregular boundaries. The Monte Carlo code developed has been applied to the determination of the electron energy distribution function and related parameters for a noble gas plasma created by alpha-particle irradiation. The characteristics of the radiation induced plasma involved are given.

Non-invasive, photonics-based diagnostic, imaging, monitoring, and light delivery techniques for the recognition, quantification and treatment of malignant and chronic inflammatory conditions

NASA Astrophysics Data System (ADS)

Davies, N.; Davies-Shaw, D.; Shaw, J. D.

2007-02-01

We report firsthand on innovative developments in non-invasive, biophotonic techniques for a wide range of diagnostic, imaging and treatment options, including the recognition and quantification of cancerous, pre-cancerous cells and chronic inflammatory conditions. These techniques have benefited from the ability to target the affected site by both monochromatic light and broad multiple wavelength spectra. The employment of such wavelength or color-specific properties embraces the fluorescence stimulation of various photosensitizing drugs, and the instigation and detection of identified fluorescence signatures attendant upon laser induced fluorescence (LIF) phenomena as transmitted and propagated by precancerous, cancerous and normal tissue. In terms of tumor imaging and therapeutic and treatment options, we have exploited the abilities of various wavelengths to penetrate to different depths, through different types of tissues, and have explored quantifiable absorption and reflection characteristics upon which diagnostic assumptions can be reliably based and formulated. These biophotonic-based diagnostic, sensing and imaging techniques have also benefited from, and have been further enhanced by, the integrated ability to provide various power levels to be employed at various stages in the procedure. Applications are myriad, including non-invasive, non destructive diagnosis of in vivo cell characteristics and functions; light-based tissue analysis; real-time monitoring and mapping of brain function and of tumor growth; real time monitoring of the surgical completeness of tumor removal during laser-imaged/guided brain resection; diagnostic procedures based on fluorescence life-time monitoring, the monitoring of chronic inflammatory conditions (including rheumatoid arthritis), and continuous blood glucose monitoring in the control of diabetes.

78 FR 36198 - Request for Public Comment: 30-Day Proposed Information Collection: Indian Health Service Medical...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-17

... supplied by the applicant and may include: Former employers, educational institutions, licensure and... technology to make the application electronically available on the Internet. The application may be found at... collection techniques or other forms of information technology. Send Requests for Further Information: For...

Performance Dialogs Implemented in a Finnish University

ERIC Educational Resources Information Center

Takala, Marjatta; Keskinen, Soili

2014-01-01

This article analyses performance dialogs (PDs) in the university context in Finland. These are held annually between employers and employees. The study was carried out to assess the efficacy of this technique. Research methods included an electronic questionnaire over two different years delivered to the whole staff of the Department of Teacher…

Characteristics of Home: Perspectives of Women Who Are Homeless

ERIC Educational Resources Information Center

Walsh, Christine A.; Rutherford, Gayle E.; Kuzmak, Natasha

2009-01-01

We employed participatory, community-based research methods to explore the perceptions of home among women who are homeless. Twenty women engaged in one or more techniques including qualitative interviews, digital story telling, creative writing, photovoice, and design charrette to characterize their perceptions of home. Analysis of the data…

Taking "O" Level GCE Examinations: The Strategies Employed by Candidates and Their Teachers.

ERIC Educational Resources Information Center

Francis, J.C.

1981-01-01

Examines the relationship of study techniques and test-taking strategies to success on the "O" level of the British General Certificate of Education (GCE) examination. Findings showed that teachers and students felt that course reviews, including study of past examinations, was the best preparation. (AM)

Maternal Work Conditions and Child Development

ERIC Educational Resources Information Center

Felfe, Christina; Hsin, Amy

2012-01-01

How do maternal work conditions, such as psychological stress and physical hazards, affect children's development? Combining data from the Child Development Supplement of the Panel Study of Income Dynamics and the Occupational Information Network allows us to shed some light on this question. We employ various techniques including OLS with…

Implementation of radiation shielding calculation methods. Volume 2: Seminar/Workshop notes

NASA Technical Reports Server (NTRS)

Capo, M. A.; Disney, R. K.

1971-01-01

Detailed descriptions are presented of the input data for each of the MSFC computer codes applied to the analysis of a realistic nuclear propelled vehicle. The analytical techniques employed include cross section data, preparation, one and two dimensional discrete ordinates transport, point kernel, and single scatter methods.

Promoting Happiness and Life Satisfaction in School Children

ERIC Educational Resources Information Center

McCabe, Kelly; Bray, Melissa A.; Kehle, Thomas J.; Theodore, Lea A.; Gelbar, Nicholas W.

2011-01-01

Studies in positive psychology, including happiness, well-being, and life satisfaction, are reviewed. The preponderance of the research literature on the promotion of positive psychology tends to focus on broad social competences. However, there is an emerging body of evidence that supports employing specific techniques that are more amenable to…

42 CFR 51.32 - Resolving disputes.

Code of Federal Regulations, 2010 CFR

2010-10-01

... reasonable time, the P&A system may pursue alternative remedies, including initiating legal action. (e) A P&A... Services § 51.32 Resolving disputes. (a) Each P&A system is encouraged to develop and employ techniques... the family member, or (3) Legally incompetent and the legal guardian, conservator or other legal...

The Geography of Connection: Bringing the World to Students.

ERIC Educational Resources Information Center

Black, Mary S.

2000-01-01

Discusses strategies used by two teachers for teaching geography to at-risk students to connect the subject matter to the student's lives. Includes techniques such as integrating music, art, language, employing simulations when teaching, using current events to improve students' reading skills, and utilizing computer technology. (CMK)

Design for Medical Education. The Development and Planning of a Medical College and Care Center.

ERIC Educational Resources Information Center

Peery, Thomas M.; Green, Alan C.

Planning and design procedures which one medical education center employed in translating its educational objectives, philosophy and techniques into laboratory, classroom and clinic facilities are described. Basic planning considerations included--(1) determination of the curriculum, (2) facility utilization rate, (3) housing of research…

Enhancing Teaching and Learning in Higher Education with a Total Multimedia Approach.

ERIC Educational Resources Information Center

Wells, F. Stuart; Kick, Russell C.

If multimedia technology is to be successfully employed to enhance classroom instruction and learning, the full capabilities of the technology must be used. The complete power of multimedia includes high quality graphics and images, sophisticated navigational techniques and transitional effects, appropriate music and sound, animation, and,…

The Impact of Collaboration, Empowerment, and Choice: An Empirical Examination of the Collaborative Course Development Method

ERIC Educational Resources Information Center

Aiken, K. Damon; Heinze, Timothy C.; Meuter, Matthew L.; Chapman, Kenneth J.

2017-01-01

This research empirically tests collaborative course development (CCD)-a pedagogy presented in the 2016 "Marketing Education Review Special Issue on Teaching Innovations". A team of researchers taught experimental courses using CCD methods (employing various techniques including syllabus building, "flex-tures," free-choice…

77 FR 15004 - Updating of Employer Identification Numbers

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

... the IRS, including whether the information will have practical utility; The accuracy of the estimated... techniques or other forms of information technology; and Estimates of capital or start-up costs and costs of... respondents are persons that have an EIN. Estimated total annual reporting burden: 403,177 hours. Estimated...

Induction of lucid dreams: a systematic review of evidence.

PubMed

Stumbrys, Tadas; Erlacher, Daniel; Schädlich, Melanie; Schredl, Michael

2012-09-01

In lucid dreams the dreamer is aware of dreaming and often able to influence the ongoing dream content. Lucid dreaming is a learnable skill and a variety of techniques is suggested for lucid dreaming induction. This systematic review evaluated the evidence for the effectiveness of induction techniques. A comprehensive literature search was carried out in biomedical databases and specific resources. Thirty-five studies were included in the analysis (11 sleep laboratory and 24 field studies), of which 26 employed cognitive techniques, 11 external stimulation and one drug application. The methodological quality of the included studies was relatively low. None of the induction techniques were verified to induce lucid dreams reliably and consistently, although some of them look promising. On the basis of the reviewed studies, a taxonomy of lucid dream induction methods is presented. Several methodological issues are discussed and further directions for future studies are proposed. Copyright © 2012 Elsevier Inc. All rights reserved.

Tumescent and syringe liposculpture: a logical partnership.

PubMed

Hunstad, J P

1995-01-01

Liposuction has been traditionally performed under general anesthesia. Standard instrumentation for the procedure has included blunt-tipped suction cannulae connected to an electric vacuum pump by noncollapsible tubing. A subcutaneous injection of Lidocaine with Epinephrine is routinely employed to minimize blood loss during the procedure. This infiltration has been described as the "wet technique," but it is not a method to supplant general anesthesia. The tumescent technique, a method of infusing very large volumes of dilute lidocaine with epinephrine solutions, has been advocated as a satisfactory means for providing conscious anesthesia for liposuction procedures, avoiding the need for general anesthesia. The syringe technique employs blunt-tipped suction cannulae connected to a syringe. Drawing back the syringe plunger generates the negative pressures needed to remove fat during liposuction and replaces the electric vacuum pump and connecting tubing traditionally used for this procedure. This study evaluates the combined tumescent and syringe techniques for liposuction. One hundred consecutive patients were treated with the tumescent technique as the sole means of anesthesia and the syringe technique as the sole means of performing liposuction. A modified tumescent formula is presented. A comparison of liposuction aspirates using this modified tumescent technique is compared and contrasted to liposuction aspirates obtained using the "dry technique" and the "wet technique." A historical review of the syringe technique and its perceived attributes is also presented. Technical descriptions of the tumescent infusion method, tumescent fluid formulation, and suggested patient sedation and monitoring is presented. Photographic documentation of patients who underwent the combined tumescent and syringe liposculpture treating various body areas is shown. A critical analysis of the limitations of this combined technique is also described noting added time requirements, difficulties with under-correction of deformities, and need for reoperation, methods for determining the "end-point" for the procedure, as well as addressing large-volume liposuction problems. The conclusion reached by this study is that combining the tumescent technique and the syringe technique is a logical partnership. Each method complements the other, allowing liposuction to be performed with considerable advantage over traditional methods. These advantages include eliminating the need for general anesthesia, lessening blood loss and postoperative bruising, greater accuracy, precision, and overall high patient satisfaction.

Machine learning and microsimulation techniques on the prognosis of dementia: A systematic literature review.

PubMed

Dallora, Ana Luiza; Eivazzadeh, Shahryar; Mendes, Emilia; Berglund, Johan; Anderberg, Peter

2017-01-01

Dementia is a complex disorder characterized by poor outcomes for the patients and high costs of care. After decades of research little is known about its mechanisms. Having prognostic estimates about dementia can help researchers, patients and public entities in dealing with this disorder. Thus, health data, machine learning and microsimulation techniques could be employed in developing prognostic estimates for dementia. The goal of this paper is to present evidence on the state of the art of studies investigating and the prognosis of dementia using machine learning and microsimulation techniques. To achieve our goal we carried out a systematic literature review, in which three large databases-Pubmed, Socups and Web of Science were searched to select studies that employed machine learning or microsimulation techniques for the prognosis of dementia. A single backward snowballing was done to identify further studies. A quality checklist was also employed to assess the quality of the evidence presented by the selected studies, and low quality studies were removed. Finally, data from the final set of studies were extracted in summary tables. In total 37 papers were included. The data summary results showed that the current research is focused on the investigation of the patients with mild cognitive impairment that will evolve to Alzheimer's disease, using machine learning techniques. Microsimulation studies were concerned with cost estimation and had a populational focus. Neuroimaging was the most commonly used variable. Prediction of conversion from MCI to AD is the dominant theme in the selected studies. Most studies used ML techniques on Neuroimaging data. Only a few data sources have been recruited by most studies and the ADNI database is the one most commonly used. Only two studies have investigated the prediction of epidemiological aspects of Dementia using either ML or MS techniques. Finally, care should be taken when interpreting the reported accuracy of ML techniques, given studies' different contexts.

Machine learning and microsimulation techniques on the prognosis of dementia: A systematic literature review

PubMed Central

Mendes, Emilia; Berglund, Johan; Anderberg, Peter

2017-01-01

Background Dementia is a complex disorder characterized by poor outcomes for the patients and high costs of care. After decades of research little is known about its mechanisms. Having prognostic estimates about dementia can help researchers, patients and public entities in dealing with this disorder. Thus, health data, machine learning and microsimulation techniques could be employed in developing prognostic estimates for dementia. Objective The goal of this paper is to present evidence on the state of the art of studies investigating and the prognosis of dementia using machine learning and microsimulation techniques. Method To achieve our goal we carried out a systematic literature review, in which three large databases—Pubmed, Socups and Web of Science were searched to select studies that employed machine learning or microsimulation techniques for the prognosis of dementia. A single backward snowballing was done to identify further studies. A quality checklist was also employed to assess the quality of the evidence presented by the selected studies, and low quality studies were removed. Finally, data from the final set of studies were extracted in summary tables. Results In total 37 papers were included. The data summary results showed that the current research is focused on the investigation of the patients with mild cognitive impairment that will evolve to Alzheimer’s disease, using machine learning techniques. Microsimulation studies were concerned with cost estimation and had a populational focus. Neuroimaging was the most commonly used variable. Conclusions Prediction of conversion from MCI to AD is the dominant theme in the selected studies. Most studies used ML techniques on Neuroimaging data. Only a few data sources have been recruited by most studies and the ADNI database is the one most commonly used. Only two studies have investigated the prediction of epidemiological aspects of Dementia using either ML or MS techniques. Finally, care should be taken when interpreting the reported accuracy of ML techniques, given studies’ different contexts. PMID:28662070

Frontal view reconstruction for iris recognition

DOEpatents

Santos-Villalobos, Hector J; Bolme, David S; Boehnen, Chris Bensing

2015-02-17

Iris recognition can be accomplished for a wide variety of eye images by correcting input images with an off-angle gaze. A variety of techniques, from limbus modeling, corneal refraction modeling, optical flows, and genetic algorithms can be used. A variety of techniques, including aspherical eye modeling, corneal refraction modeling, ray tracing, and the like can be employed. Precomputed transforms can enhance performance for use in commercial applications. With application of the technologies, images with significantly unfavorable gaze angles can be successfully recognized.

Digital television system design study

NASA Technical Reports Server (NTRS)

Huth, G. K.

1976-01-01

The use of digital techniques for transmission of pictorial data is discussed for multi-frame images (television). Video signals are processed in a manner which includes quantization and coding such that they are separable from the noise introduced into the channel. The performance of digital television systems is determined by the nature of the processing techniques (i.e., whether the video signal itself or, instead, something related to the video signal is quantized and coded) and to the quantization and coding schemes employed.

Evaluation of vibrated fluidized bed techniques in coating hemosorbents.

PubMed

Morley, D B

1991-06-01

A coating technique employing a vibrated fluidized bed was used to apply an ultrathin (2 microns) cellulose nitrate coating to synthetic bead activated charcoal. In vitro characteristics of the resulting coated sorbent, including permeability to model small and middle molecules, and mechanical integrity, were evaluated to determine the suitability of the process in coating granular sorbents used in hemoperfusion. Initial tests suggest the VFB-applied CN coating is both highly uniform and tightly adherent and warrants further investigation as a hemosorbent coating.

A general study of techniques for ultraviolet astrophysical studies on space vehicles

NASA Technical Reports Server (NTRS)

Moos, H. W.; Fastie, W. G.; Davidsen, A. F.

1977-01-01

Recent accomplishments in three areas of UV instrumentation for space astronomy are discussed. These areas include reliable UV photometry, sensitive photon-detection techniques, and precise telescope pointing. Calibration facilities for spectrometers designed to operate in the spectral regions above 1200 A and down to 400 A are described which employ a series of diodes calibrated against electron synchrotron radiation as well as other radiometric standards. Improvements in photon-detection sensitivity achieved with the aid of pulse-counting electronics and multispectral detectors are reported, and the technique of precise subarcsecond telescope pointing is briefly noted. Some observational results are presented which demonstrate the advantages and precision of the instruments and techniques considered.

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.

Sparse Reconstruction Techniques in MRI: Methods, Applications, and Challenges to Clinical Adoption

PubMed Central

Yang, Alice Chieh-Yu; Kretzler, Madison; Sudarski, Sonja; Gulani, Vikas; Seiberlich, Nicole

2016-01-01

The family of sparse reconstruction techniques, including the recently introduced compressed sensing framework, has been extensively explored to reduce scan times in Magnetic Resonance Imaging (MRI). While there are many different methods that fall under the general umbrella of sparse reconstructions, they all rely on the idea that a priori information about the sparsity of MR images can be employed to reconstruct full images from undersampled data. This review describes the basic ideas behind sparse reconstruction techniques, how they could be applied to improve MR imaging, and the open challenges to their general adoption in a clinical setting. The fundamental principles underlying different classes of sparse reconstructions techniques are examined, and the requirements that each make on the undersampled data outlined. Applications that could potentially benefit from the accelerations that sparse reconstructions could provide are described, and clinical studies using sparse reconstructions reviewed. Lastly, technical and clinical challenges to widespread implementation of sparse reconstruction techniques, including optimization, reconstruction times, artifact appearance, and comparison with current gold-standards, are discussed. PMID:27003227

Various extraction and analytical techniques for isolation and identification of secondary metabolites from Nigella sativa seeds.

PubMed

Liu, X; Abd El-Aty, A M; Shim, J-H

2011-10-01

Nigella sativa L. (black cumin), commonly known as black seed, is a member of the Ranunculaceae family. This seed is used as a natural remedy in many Middle Eastern and Far Eastern countries. Extracts prepared from N. sativa have, for centuries, been used for medical purposes. Thus far, the organic compounds in N. sativa, including alkaloids, steroids, carbohydrates, flavonoids, fatty acids, etc. have been fairly well characterized. Herein, we summarize some new extraction techniques, including microwave assisted extraction (MAE) and supercritical extraction techniques (SFE), in addition to the classical method of hydrodistillation (HD), which have been employed for isolation and various analytical techniques used for the identification of secondary metabolites in black seed. We believe that some compounds contained in N. sativa remain to be identified, and that high-throughput screening could help to identify new compounds. A study addressing environmentally-friendly techniques that have minimal or no environmental effects is currently underway in our laboratory.

Soot Volume Fraction Imaging

NASA Technical Reports Server (NTRS)

Greenberg, Paul S.; Ku, Jerry C.

1994-01-01

A new technique is described for the full-field determination of soot volume fractions via laser extinction measurements. This technique differs from previously reported point-wise methods in that a two-dimensional array (i.e., image) of data is acquired simultaneously. In this fashion, the net data rate is increased, allowing the study of time-dependent phenomena and the investigation of spatial and temporal correlations. A telecentric imaging configuration is employed to provide depth-invariant magnification and to permit the specification of the collection angle for scattered light. To improve the threshold measurement sensitivity, a method is employed to suppress undesirable coherent imaging effects. A discussion of the tomographic inversion process is provided, including the results obtained from numerical simulation. Results obtained with this method from an ethylene diffusion flame are shown to be in close agreement with those previously obtained by sequential point-wise interrogation.

A review of microdialysis coupled to microchip electrophoresis for monitoring biological events

PubMed Central

Saylor, Rachel A.; Lunte, Susan M.

2015-01-01

Microdialysis is a powerful sampling technique that enables monitoring of dynamic processes in vitro and in vivo. The combination of microdialysis with chromatographic or electrophoretic methods yields along with selective detection methods yields a “separation-based sensor” capable of monitoring multiple analytes in near real time. Analysis of microdialysis samples requires techniques that are fast (<1 min), have low volume requirements (nL–pL), and, ideally, can be employed on-line. Microchip electrophoresis fulfills these requirements and also permits the possibility of integrating sample preparation and manipulation with detection strategies directly on-chip. Microdialysis coupled to microchip electrophoresis has been employed for monitoring biological events in vivo and in vitro. This review discusses technical considerations for coupling microdialysis sampling and microchip electrophoresis, including various interface designs, and current applications in the field. PMID:25637011

Efficiency measurement of health care organizations: What models are used?

PubMed Central

Jaafaripooyan, Ebrahim; Emamgholipour, Sara; Raei, Behzad

2017-01-01

Background: Literature abounds with various techniques for efficiency measurement of health care organizations (HCOs), which should be used cautiously and appropriately. The present study aimed at discovering the rules regulating the interplay among the number of inputs, outputs, and decision- making units (DMUs) and identifying all methods used for the measurement of Iranian HCOs and critically appraising all DEA studies on Iranian HCOs in their application of such rules. Methods: The present study employed a systematic search of all studies related to efficiency measurement of Iranian HCOs. A search was conducted in different databases such as PubMed and Scopus between 2001 and 2015 to identify the studies related to the measurement in health care. The retrieved studies passed through a multi-stage (title, abstract, body) filtering process. Data extraction table for each study was completed and included method, number of inputs and outputs, DMUs, and their efficiency score. Results: Various methods were found for efficiency measurement. Overall, 122 studies were retrieved, of which 73 had exclusively employed DEA technique for measuring the efficiency of HCOs in Iran, and 23 with hybrid models (including DEA). Only 6 studies had explicitly used the rules of thumb. Conclusion: The number of inputs, outputs, and DMUs should be cautiously selected in DEA like techniques, as their proportionality can directly affect the discriminatory power of the technique. The given literature seemed to be, to a large extent, unsuccessful in attending to such proportionality. This study collected a list of key rules (of thumb) on the interplay of inputs, outputs, and DMUs, which could be considered by most researchers keen to apply DEA technique.

Measurement of complex terahertz dielectric properties of polymers using an improved free-space technique

NASA Astrophysics Data System (ADS)

Chang, Tianying; Zhang, Xiansheng; Yang, Chuanfa; Sun, Zhonglin; Cui, Hong-Liang

2017-04-01

The complex dielectric properties of non-polar solid polymer materials were measured in the terahertz (THz) band by a free-space technique employing a frequency-extended vector network analyzer (VNA), and by THz time-domain spectroscopy (TDS). Mindful of THz wave’s unique characteristics, the free-space method for measurement of material dielectric properties in the microwave band was expanded and improved for application in the THz frequency region. To ascertain the soundness and utility of the proposed method, measurements of the complex dielectric properties of a variety of polymers were carried out, including polytetrafluoroethylene (PTFE, known also by the brand name Teflon), polypropylene (PP), polyethylene (PE), and glass fiber resin (Composite Stone). The free-space method relies on the determination of electromagnetic scattering parameters (S-parameters) of the sample, with the gated-reflect-line (GRL) calibration technique commonly employed using a VNA. Subsequently, based on the S-parameters, the dielectric constant and loss characteristic of the sample were calculated by using a Newtonian iterative algorithm. To verify the calculated results, THz TDS technique, which produced Fresnel parameters such as reflection and transmission coefficients, was also used to independently determine the dielectric properties of these polymer samples, with results satisfactorily corroborating those obtained by the free-space extended microwave technique.

Behaviour change techniques and contraceptive use in low and middle income countries: a review.

PubMed

Phiri, Mwelwa; King, R; Newell, J N

2015-10-30

We aimed to identify effective behaviour change techniques to increase modern contraceptive use in low and middle income countries (LMICs). Literature was identified in Global Health, Web of Science, MEDLINE, PsycINFO and Popline, as well as peer reviewed journals. Articles were included if they were written in English, had an outcome evaluation of contraceptive use, modern contraceptive use, contraceptive initiation/uptake, contraceptive adherence or continuation of contraception, were a systematic review or randomised controlled trial, and were conducted in a low or middle income country. We assessed the behaviour change techniques used in each intervention and included a new category of male partner involvement. We identified six studies meeting the inclusion criteria. The most effective interventions were those that involve male partner involvement in the decision to initiate contraceptive use. The findings also suggest that providing access to contraceptives in the community promotes their use. The interventions that had positive effects on contraceptive use used a combination of behaviour change techniques. Performance techniques were not used in any of the interventions. The use of social support techniques, which are meant to improve wider social acceptability, did not appear except in two of the interventions. Our findings suggest that when information and contraceptives are provided, contraceptive use improves. Recommendations include reporting of behaviour change studies to include more details of the intervention and techniques employed. There is also a need for further research to understand which techniques are especially effective.

The Conceptualization and Measurement of Equity in School Finance in Virginia.

ERIC Educational Resources Information Center

Verstegen, Deborah A.; Salmon, Richard G.

1989-01-01

Employed various statistical techniques to measure fiscal equity in Virginia. The new state aid system for financing education was unable to mitigate large and increasing disparities in education revenues between more and less affluent localities and a strong and growing linkage between revenue and wealth. Includes 34 footnotes. (MLH)

Marketing and the Management of Public Schools: Borrowing from Business.

ERIC Educational Resources Information Center

Nebgen, Mary K.

1983-01-01

Many techniques that American business has developed for marketing goods and services can be used to build public support for the schools. Practical elements of a marketing plan include: (1) developing a customer philosophy; (2) creating an organizational image; (3) employing and supporting marketing personnel; (4) communications; and (5)…

Progress in our understanding of cometary dust tails

NASA Technical Reports Server (NTRS)

Sekanina, Z.

1976-01-01

Various analytical techniques are employed to analyze observations on the character, composition, and size distribution of solid particles in cometary dust tails. Emphasized is the mechanical theory that includes solar gravitational attraction and solar radiation pressure to explain dust particle motions in cometary tails, as well as interactions between dust and plasma.

Curriculum Guide for Vocational Teacher-Coordinators of Intensive Business Training.

ERIC Educational Resources Information Center

Mississippi Research and Curriculum Unit for Vocational and Technical Education, State College.

Intensive Business Training in Mississippi is designed to prepare students for immediate employment in secretarial and clerical jobs in a business office. It includes the learning and mastering of office procedures and techniques, with emphasis on depth and practice of putting basic office skills into vocational experience and practice. The two or…

Two-Paycheck Families: Techniques To Ease the Strains and Build the Strengths.

ERIC Educational Resources Information Center

Chambliss, Catherine; Hartl, Alan

American family life is being transformed by both parents increasingly becoming employed. This change has created a need for strategies to assist single-parent and two-paycheck families. Two-paycheck families present problems to clinical psychologists. External demands on these families include the demands of the workplace, children's needs, the…

Primer in Public Sector Labor Relations. A Practitioner's Guide.

ERIC Educational Resources Information Center

Indiana Univ., Bloomington. Midwest Center for Public Sector Labor Relations.

This guide is intended as a brief primer for the employer or employee new to public sector labor relations. A simple step-by-step approach to labor relations includes techniques for analysis of state enabling legislation, union self-perpetuation, scope of bargaining, preparing for and winning bargaining, settling disputes, solving contract…

Empowering Chicana/o and Latina: A Framework for High School Counselors

ERIC Educational Resources Information Center

Padilla, Alejandro

2014-01-01

Using Hipolito-Delgado and Lee's empowerment theory for the professional school counselor as a framework, this qualitative study explored the techniques employed by school counselors to facilitate the empowerment of Chicana/o and Latina/o students in large California urban high schools. The qualitative methodology included in-depth interviews…

Compressed Speech Technology: Implications for Learning and Instruction.

ERIC Educational Resources Information Center

Sullivan, LeRoy L.

This paper first traces the historical development of speech compression technology, which has made it possible to alter the spoken rate of a pre-recorded message without excessive distortion. Terms used to describe techniques employed as the technology evolved are discussed, including rapid speech, rate altered speech, cut-and-spliced speech, and…

A Primer on Brain Imaging in Developmental Psychopathology: What Is It Good For?

ERIC Educational Resources Information Center

Pine, Daniel S.

2006-01-01

This primer introduces a Special Section on brain imaging, which includes a commentary and 10 data papers presenting applications of brain imaging to questions on developmental psychopathology. This primer serves two purposes. First, the article summarizes the strength and weaknesses of various brain-imaging techniques typically employed in…

Using Simulations to Investigate the Longitudinal Stability of Alternative Schemes for Classifying and Identifying Children with Reading Disabilities

ERIC Educational Resources Information Center

Schatschneider, Christopher; Wagner, Richard K.; Hart, Sara A.; Tighe, Elizabeth L.

2016-01-01

The present study employed data simulation techniques to investigate the 1-year stability of alternative classification schemes for identifying children with reading disabilities. Classification schemes investigated include low performance, unexpected low performance, dual-discrepancy, and a rudimentary form of constellation model of reading…

Exploring a Monetary Union among Nations through Active Learning

ERIC Educational Resources Information Center

Goma, Ophelia D.

2002-01-01

This article presents a classroom project that employs various techniques of active learning including role-playing, collaborative group work and writing. The project explores the recent creation of the European Monetary Union (EMU) with special emphasis on the introduction of the euro. The project assumes that the Americas have begun preliminary…

Occupationally Related Science. Draft Curriculum 1986-87.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Div. of Occupational Education Programs.

To prepare occupational students for employment, a basic understanding of scientific knowledge and the processes of science that have been applied in the development of tools, machines, instruments, and technological techniques or processes should be taught. When a second unit of science was included for all high school students in the New York…

Positioning challenges in reconfigurable semi-autonomous robotic NDE inspection

NASA Astrophysics Data System (ADS)

Pierce, S. Gareth; Dobie, Gordon; Summan, Rahul; Mackenzie, Liam; Hensman, James; Worden, Keith; Hayward, Gordon

2010-03-01

This paper describes work conducted into mobile, wireless, semi-autonomous NDE inspection robots developed at The University of Strathclyde as part of the UK Research Centre for Non Destructive Evaluation (RCNDE). The inspection vehicles can incorporate a number of different NDE payloads including ultrasonic, eddy current, visual and magnetic based payloads, and have been developed to try and improve NDE inspection techniques in challenging inspection areas (for example oil, gas, and nuclear structures). A significant research challenge remains in the accurate positioning and guidance of such vehicles for real inspection tasks. Employing both relative and absolute position measurements, we discuss a number of approaches to position estimation including Kalman and particle filtering. Using probabilistic approaches enables a common mathematical framework to be employed for both positioning and data fusion from different NDE sensors. In this fashion the uncertainties in both position and defect identification and classification can be dealt with using a consistent approach. A number of practical constraints and considerations to different precision positioning techniques are discussed, along with NDE applications and the potential for improved inspection capabilities by utilising the inherent reconfigurable capabilities of the inspection vehicles.

Airborne sulfur trace species intercomparison campaign: Sulfur dioxide, dimethylsulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide

NASA Technical Reports Server (NTRS)

Gregory, Gerald L.; Hoell, James M., Jr.; Davis, Douglas D.

1991-01-01

Results from an airborne intercomparison of techniques to measure tropospheric levels of sulfur trace gases are presented. The intercomparison was part of the NASA Global Tropospheric Experiment (GTE) and was conducted during the summer of 1989. The intercomparisons were conducted on the Wallops Electra aircraft during flights from Wallops Island, Virginia, and Natal, Brazil. Sulfur measurements intercompared included sulfur dioxide (SO2), dimethylsulfide (DMS), hydrogen sulfide (H2S), carbon disulfide (CS2), and carbonyl sulfide (OCS). Measurement techniques ranged from filter collection systems with post-flight analyses to mass spectrometer and gas chromatograph systems employing various methods for measuring and identifying the sulfur gases during flight. Sampling schedules for the techniques ranged from integrated collections over periods as long as 50 minutes to one- to three-minute samples every ten or fifteen minutes. Several of the techniques provided measurements of more than one sulfur gas. Instruments employing different detection principles were involved in each of the sulfur intercomparisons. Also included in the intercomparison measurement scenario were a host of supporting measurements (i.e., ozone, nitrogen oxides, carbon monoxide, total sulfur, aerosols, etc.) for purposes of: (1) interpreting results (i.e., correlation of any noted instrument disagreement with the chemical composition of the measurement environment); and (2) providing supporting chemical data to meet CITE-3 science objectives of studying ozone/sulfur photochemistry, diurnal cycles, etc. The results of the intercomparison study are briefly discussed.

Photoacoustic imaging of angiogenesis in a subcutaneous islet transplant site in a murine model

NASA Astrophysics Data System (ADS)

Shi, Wei; Pawlick, Rena; Bruni, Antonio; Rafiei, Yasmin; Pepper, Andrew R.; Gala-Lopez, Boris; Choi, Min; Malcolm, Andrew; Zemp, Roger J.; Shapiro, A. M. James

2016-06-01

Islet transplantation (IT) is an established clinical therapy for select patients with type-1 diabetes. Clinically, the hepatic portal vein serves as the site for IT. Despite numerous advances in clinical IT, limitations remain, including early islet cell loss posttransplant, procedural complications, and the inability to effectively monitor islet grafts. Hence, alternative sites for IT are currently being explored, with the subcutaneous space as one potential option. When left unmodified, the subcutaneous space routinely fails to promote successful islet engraftment. However, when employing the previously developed subcutaneous "deviceless" technique, a favorable microenvironment for islet survival and function is established. In this technique, an angiocatheter was temporarily implanted subcutaneously, which facilitated angiogenesis to promote subsequent islet engraftment. This technique has been employed in preclinical animal models, providing a sufficient means to develop techniques to monitor functional aspects of the graft such as angiogenesis. Here, we utilize photoacoustic imaging to track angiogenesis during the priming of the subcutaneous site by the implanted catheter at 1 to 4 weeks postcatheter. Quantitative analysis on vessel densities shows gradual growth of vasculature in the implant position. These results demonstrate the ability to track angiogenesis, thus facilitating a means to optimize and assess the pretransplant microenvironment.

Modeling of switching regulator power stages with and without zero-inductor-current dwell time

NASA Technical Reports Server (NTRS)

Lee, F. C. Y.; Yu, Y.

1979-01-01

State-space techniques are employed to derive accurate models for the three basic switching converter power stages: buck, boost, and buck/boost operating with and without zero-inductor-current dwell time. A generalized procedure is developed which treats the continuous-inductor-current mode without dwell time as a special case of the discontinuous-current mode when the dwell time vanishes. Abrupt changes of system behavior, including a reduction of the system order when the dwell time appears, are shown both analytically and experimentally. Merits resulting from the present modeling technique in comparison with existing modeling techniques are illustrated.

Middle Atmosphere Program. Handbook for MAP, volume 19

NASA Technical Reports Server (NTRS)

Goldberg, R. A. (Editor)

1986-01-01

This MAP handbook is concerned with rocket techniques and instrumentation as they are currently employed in the middle atmosphere. It is composed of nine chapters, written by experts on rocket experiments. The emphasis is on measurement techniques rather than results, although results are incorporated wherever they provide examples which illustrate the measurement features. The chapters first cover techniques relating to measurements of neutral dynamics and chemistry, then measurements of the various intermittent and excessive radiation sources which effect the middle atmospheric environment, and finally measurements of the plasma environment including electric fields. The weighting toward plasma related parameters is not accidental, but reflects both the historical headstart given by early development of radio wave and probe techniques to measure electron density, and by the relatively limited number of techniques available for neutral atmospheric measurements.

Teachers of the Alexander Technique in the UK and the people who take their lessons: A national cross-sectional survey.

PubMed

Eldred, J; Hopton, A; Donnison, E; Woodman, J; MacPherson, H

2015-06-01

Given the rising profile of the Alexander Technique in the UK, there is a need for a comprehensive description of its teachers and of those who currently take lessons. In a national survey of Alexander teachers, we set out to address this information gap. A cross-sectional survey of 871 UK members of three main Alexander Technique teachers' professional associations was conducted. A questionnaire requested information about their professional background, teaching practice and methods, and about the people who attend lessons and their reasons for seeking help. With an overall response rate of 61%, 534 teachers responded; 74% were female with median age of 58 years, 60% had a higher education qualification, and 95% were self-employed, many with additional non-Alexander paid employment. The majority (87%) offered lessons on their own premises or in a privately rented room, and 19% provided home visits; both individual and group lessons were provided. People who took lessons were predominantly female (66%) with a median age of 48 years, and 91% paid for their lessons privately. Nearly two-thirds (62%) began lessons for reasons related to musculoskeletal conditions, including back symptoms, posture, neck pain, and shoulder pain. Other reasons were general (18%, including well-being), performance-related (10%, including voice-, music-, and sport-related), psychological (5%) and neurological (3%). We estimate that Alexander teachers in the UK provide approximately 400,000 lessons per year. This study provides an overview of Alexander Technique teaching in the UK today and data that may be useful when planning future research. Copyright © 2015 Elsevier Ltd. All rights reserved.

Summary of investigations of engine response to distorted inlet conditions

NASA Technical Reports Server (NTRS)

Biesiadny, T. J.; Braithwaite, W. M.; Soeder, R. H.; Abdelwahab, M.

1986-01-01

A survey is presented of experimental and analytical experience of the NASA Lewis Research Center in engine response to inlet temperature and pressure distortions. This includes a description of the hardware and techniques employed, and a summary of the highlights of experimental investigations and analytical modeling. Distortion devices successfully simulated inlet distortion, and knowledge was gained about compression system response to different types of distortion. A list of NASA research references is included.

Metalloproteomics: Forward and Reverse Approaches in Metalloprotein Structural and Functional Characterization

PubMed Central

Shi, Wuxian; Chance, Mark R.

2010-01-01

About one-third of all proteins are associated with a metal. Metalloproteomics is defined as the structural and functional characterization of metalloproteins on a genome-wide scale. The methodologies utilized in metalloproteomics, including both forward (bottom-up) and reverse (top-down) technologies, to provide information on the identity, quantity and function of metalloproteins are discussed. Important techniques frequently employed in metalloproteomics include classical proteomics tools such as mass spectrometry and 2-D gels, immobilized-metal affinity chromatography, bioinformatics sequence analysis and homology modeling, X-ray absorption spectroscopy and other synchrotron radiation based tools. Combinative applications of these techniques provide a powerful approach to understand the function of metalloproteins. PMID:21130021

High Contrast Internal and External Coronagraph Masks Produced by Various Techniques

NASA Technical Reports Server (NTRS)

Balasubramanian, Kunjithapatha; Wilson, Daniel; White, Victor; Muller, Richard; Dickie, Matthew; Yee, Karl; Ruiz, Ronald; Shaklan, Stuart; Cady, Eric; Kern, Brian;

Federal and State Employment Laws. Module Number 11. Work Experience Program Modules. Coordination Techniques Series.

ERIC Educational Resources Information Center

Kidney, John

This self-instructional module, the eleventh in a series of 16 on techniques for coordinating work experience programs, deals with federal and state employment laws. Addressed in the module are federal and state employment laws pertaining to minimum wage for student learners, minimum wage for full-time students, unemployment insurance, child labor…

Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis

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

Meyer, Matthew W.

2013-01-01

This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include themore » inherently weak Raman cross section and susceptibility to fluorescence interference.« less

Assessing the Effectiveness of Statistical Classification Techniques in Predicting Future Employment of Participants in the Temporary Assistance for Needy Families Program

ERIC Educational Resources Information Center

Montoya, Isaac D.

2008-01-01

Three classification techniques (Chi-square Automatic Interaction Detection [CHAID], Classification and Regression Tree [CART], and discriminant analysis) were tested to determine their accuracy in predicting Temporary Assistance for Needy Families program recipients' future employment. Technique evaluation was based on proportion of correctly…

An overview of the sustainability of solid waste management at military installations

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

Borglin, S.; Shore, J.; Worden, H.

2009-08-15

Sustainable municipal solid waste management at military solutions necessitates a combined approach that includes waste reduction, alternative disposal techniques, and increased recycling. Military installations are unique because they often represent large employers in the region in which they are located, thereby making any practices they employ impact overall waste management strategies of the region. Solutions for waste sustainability will be dependent on operational directives and base location, availability of resources such as water and energy, and size of population. Presented in this paper are descriptions of available waste strategies that can be used to support sustainable waste management. Results presentedmore » indicate source reduction and recycling to be the most sustainable solutions. However, new waste-to-energy plants and composting have potential to improve on these well proven techniques and allow military installations to achieve sustainable waste management.« less

Revealing the glass transition in shape memory polymers using Brillouin spectroscopy.

PubMed

Steelman, Zachary A; Weems, Andrew C; Traverso, Andrew J; Szafron, Jason M; Maitland, Duncan J; Yakovlev, Vladislav V

2017-12-11

Emerging medical devices which employ shape memory polymers (SMPs) require precise measurements of the glass transition temperature (T g ) to ensure highly controlled shape recovery kinetics. Conventional techniques like differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) have limitations that prevent utilization for certain devices, including limited accuracy and the need for sacrificial samples. In this report, we employ an approach based on Brillouin spectroscopy to probe the glass transition of SMPs rapidly, remotely, and nondestructively. Further, we compare the T g obtained from Brillouin scattering with DMA- and DSC-measured T g to demonstrate the accuracy of Brillouin scattering for this application. We conclude that Brillouin spectroscopy is an accurate technique for obtaining the glass transition temperature of SMPs, aligning closely with the most common laboratory standards while providing a rapid, remote, and nondestructive method for the analysis of unique polymeric medical devices.

Revealing the glass transition in shape memory polymers using Brillouin spectroscopy

NASA Astrophysics Data System (ADS)

Steelman, Zachary A.; Weems, Andrew C.; Traverso, Andrew J.; Szafron, Jason M.; Maitland, Duncan J.; Yakovlev, Vladislav V.

2017-12-01

Emerging medical devices which employ shape memory polymers (SMPs) require precise measurements of the glass transition temperature (Tg) to ensure highly controlled shape recovery kinetics. Conventional techniques like differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) have limitations that prevent utilization for certain devices, including limited accuracy and the need for sacrificial samples. In this report, we employ an approach based on Brillouin spectroscopy to probe the glass transition of SMPs rapidly, remotely, and nondestructively. Further, we compare the Tg obtained from Brillouin scattering with DMA- and DSC-measured Tg to demonstrate the accuracy of Brillouin scattering for this application. We conclude that Brillouin spectroscopy is an accurate technique for obtaining the glass transition temperature of SMPs, aligning closely with the most common laboratory standards while providing a rapid, remote, and nondestructive method for the analysis of unique polymeric medical devices.

Multidirectional mobilities: Advanced measurement techniques and applications

NASA Astrophysics Data System (ADS)

Ivarsson, Lars Holger

Today high noise-and-vibration comfort has become a quality sign of products in sectors such as the automotive industry, aircraft, components, households and manufacturing. Consequently, already in the design phase of products, tools are required to predict the final vibration and noise levels. These tools have to be applicable over a wide frequency range with sufficient accuracy. During recent decades a variety of tools have been developed such as transfer path analysis (TPA), input force estimation, substructuring, coupling by frequency response functions (FRF) and hybrid modelling. While these methods have a well-developed theoretical basis, their application combined with experimental data often suffers from a lack of information concerning rotational DOFs. In order to measure response in all 6 DOFs (including rotation), a sensor has been developed, whose special features are discussed in the thesis. This transducer simplifies the response measurements, although in practice the excitation of moments appears to be more difficult. Several excitation techniques have been developed to enable measurement of multidirectional mobilities. For rapid and simple measurement of the loaded mobility matrix, a MIMO (Multiple Input Multiple Output) technique is used. The technique has been tested and validated on several structures of different complexity. A second technique for measuring the loaded 6-by-6 mobility matrix has been developed. This technique employs a model of the excitation set-up, and with this model the mobility matrix is determined from sequential measurements. Measurements on ``real'' structures show that both techniques give results of similar quality, and both are recommended for practical use. As a further step, a technique for measuring the unloaded mobilities is presented. It employs the measured loaded mobility matrix in order to calculate compensation forces and moments, which are later applied in order to compensate for the loading of the measurement equipment. The developed measurement techniques have been used in a hybrid coupling of a plate-and-beam structure to study different aspects of the coupling technique. Results show that RDOFs are crucial and have to be included in this case. The importance of stiffness residuals when mobilities are estimated from modal superposition is demonstrated. Finally it is shown that proper curve fitting can correct errors from inconsistently measured data.

TOPICAL REVIEW: Spatial localization in nuclear magnetic resonance spectroscopy

NASA Astrophysics Data System (ADS)

Keevil, Stephen F.

2006-08-01

The ability to select a discrete region within the body for signal acquisition is a fundamental requirement of in vivo NMR spectroscopy. Ideally, it should be possible to tailor the selected volume to coincide exactly with the lesion or tissue of interest, without loss of signal from within this volume or contamination with extraneous signals. Many techniques have been developed over the past 25 years employing a combination of RF coil properties, static magnetic field gradients and pulse sequence design in an attempt to meet these goals. This review presents a comprehensive survey of these techniques, their various advantages and disadvantages, and implications for clinical applications. Particular emphasis is placed on the reliability of the techniques in terms of signal loss, contamination and the effect of nuclear relaxation and J-coupling. The survey includes techniques based on RF coil and pulse design alone, those using static magnetic field gradients, and magnetic resonance spectroscopic imaging. Although there is an emphasis on techniques currently in widespread use (PRESS, STEAM, ISIS and MRSI), the review also includes earlier techniques, in order to provide historical context, and techniques that are promising for future use in clinical and biomedical applications.

Passive Sensor Integration for Vehicle Self-Localization in Urban Traffic Environment †

PubMed Central

Gu, Yanlei; Hsu, Li-Ta; Kamijo, Shunsuke

2015-01-01

This research proposes an accurate vehicular positioning system which can achieve lane-level performance in urban canyons. Multiple passive sensors, which include Global Navigation Satellite System (GNSS) receivers, onboard cameras and inertial sensors, are integrated in the proposed system. As the main source for the localization, the GNSS technique suffers from Non-Line-Of-Sight (NLOS) propagation and multipath effects in urban canyons. This paper proposes to employ a novel GNSS positioning technique in the integration. The employed GNSS technique reduces the multipath and NLOS effects by using the 3D building map. In addition, the inertial sensor can describe the vehicle motion, but has a drift problem as time increases. This paper develops vision-based lane detection, which is firstly used for controlling the drift of the inertial sensor. Moreover, the lane keeping and changing behaviors are extracted from the lane detection function, and further reduce the lateral positioning error in the proposed localization system. We evaluate the integrated localization system in the challenging city urban scenario. The experiments demonstrate the proposed method has sub-meter accuracy with respect to mean positioning error. PMID:26633420

Acceleration techniques for dependability simulation. M.S. Thesis

NASA Technical Reports Server (NTRS)

Barnette, James David

1995-01-01

As computer systems increase in complexity, the need to project system performance from the earliest design and development stages increases. We have to employ simulation for detailed dependability studies of large systems. However, as the complexity of the simulation model increases, the time required to obtain statistically significant results also increases. This paper discusses an approach that is application independent and can be readily applied to any process-based simulation model. Topics include background on classical discrete event simulation and techniques for random variate generation and statistics gathering to support simulation.

Basic forest cover mapping using digitized remote sensor data and automated data processing techniques

NASA Technical Reports Server (NTRS)

Coggeshall, M. E.; Hoffer, R. M.

1973-01-01

Remote sensing equipment and automatic data processing techniques were employed as aids in the institution of improved forest resource management methods. On the basis of automatically calculated statistics derived from manually selected training samples, the feature selection processor of LARSYS selected, upon consideration of various groups of the four available spectral regions, a series of channel combinations whose automatic classification performances (for six cover types, including both deciduous and coniferous forest) were tested, analyzed, and further compared with automatic classification results obtained from digitized color infrared photography.

Social inequalities in 'sickness': European welfare states and non-employment among the chronically ill.

PubMed

van der Wel, Kjetil A; Dahl, Espen; Thielen, Karsten

2011-12-01

The aim of this paper is to examine educational inequalities in the risk of non-employment among people with illnesses and how they vary between European countries with different welfare state characteristics. In doing so, the paper adds to the growing literature on welfare states and social inequalities in health by studying the often overlooked 'sickness'-dimension of health, namely employment behaviour among people with illnesses. We use European Union Statistics on Income and Living Conditions (EU-SILC) data from 2005 covering 26 European countries linked to country characteristics derived from Eurostat and OECD that include spending on active labour market policies, benefit generosity, income inequality, and employment protection. Using multilevel techniques we find that comprehensive welfare states have lower absolute and relative social inequalities in sickness, as well as more favourable general rates of non-employment. Hence, regarding sickness, welfare resources appear to trump welfare disincentives. Copyright © 2011 Elsevier Ltd. All rights reserved.

Multipurpose panel, phase 1, study report. [display utilizing multiplexing and digital techniques

NASA Technical Reports Server (NTRS)

Parkin, W.

1975-01-01

The feasibility of a multipurpose panel which provides a programmable electronic display for changeable panel nomenclature, multiplexes similar indicator display signals to the signal display, and demultiplexes command signals is examined. Topics discussed include: electronic display technology, miniaturized electronic and memory devices, and data management systems which employ digital address and multiplexing.

Annual Tree Growth Predictions From Periodic Measurements

Treesearch

Quang V. Cao

2004-01-01

Data from annual measurements of a loblolly pine (Pinus taeda L.) plantation were available for this study. Regression techniques were employed to model annual changes of individual trees in terms of diameters, heights, and survival probabilities. Subsets of the data that include measurements every 2, 3, 4, 5, and 6 years were used to fit the same...

The Universe at Ultraviolet Wavelengths: The first two years of International Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Chapman, R. D. (Editor)

1981-01-01

Highlights of the results obtained from the IUE satellite are addressed. specific topics discussed include the solar system, O-A stars, F-M stars, binary stars and highly evolved objects, nebulae and interstellar medium, and extragalactic objects. Data reduction techniques employed in the analysis of the varied data are also discussed.

Introduction to LISREL: A Demonstration Using Students' Commitment to an Institution. ASHE 1987 Annual Meeting Paper.

ERIC Educational Resources Information Center

Stage, Frances K.

The nature and use of LISREL (LInear Structural RELationships) analysis are considered, including an examination of college students' commitment to a university. LISREL is a fairly new causal analysis technique that has broad application in the social sciences and that employs structural equation estimation. The application examined in this paper…

Interventions for Echolalic Behaviour for Children with Autism: A Review of Verbal Prompts and the Cues Pause Point Procedure.

ERIC Educational Resources Information Center

Kavon, Nicole M.; McLaughlin, T. F.

1995-01-01

This paper examines behavior interventions for echolalic behavior in children with autism, including verbal prompting (focusing on the echolalic behavior itself) and the cues-pause-point procedure (which employs the child's prerequisite skills to teach correct verbal responses). A review of the literature indicated that both techniques were…

Literacy Education and Social Change Efforts in Pre-Communist China: The Mass Education Movement 1922-1949.

ERIC Educational Resources Information Center

Paulston, Rolland G.

Socioeconomic development in China between the two world wars included an extensive mass education effort by reform-minded young Chinese. Focusing on adult literacy and rural reconstruction, Chinese educators employed various strategies to stimulate and assist self-help efforts in Chinese villages. Paramount among these educational techniques were…

Implementing and Assessing the Effects of Theatre Infused Reading Instruction in Sixth, Seventh, and Eighth Grade Middle School English Classrooms

ERIC Educational Resources Information Center

Eyerly, William J., Jr.

2017-01-01

Theatre instructional techniques, including reader's theatre and process drama teaching strategies, have been employed as instructional strategies in classrooms to enhance reading comprehension and vocabulary learning in students. In this era of increasing accountability for educational outcomes, quantifying what, if any, impact such instructional…

Photoacoustic and luminescence spectroscopy of benzil crystals

NASA Astrophysics Data System (ADS)

Bonno, B.; Laporte, J. L.; Rousset, Y.

1991-06-01

In the present work, both photoacoustic and luminescence techniques were employed to study molecular crystals. This paper presents an extension of the standard Rosencwaig-Gersho photoacoustic model to molecular crystals, which includes finite-deexcitation-time effects and excited-state populations. In the temperature range 100-300 K, the phosphorescence quantum yield and thermal diffusivity of benzil crystals were determined.

Designs for surge immunity in critical electronic facilities

NASA Technical Reports Server (NTRS)

Roberts, Edward F., Jr.

1991-01-01

In recent years, Federal Aviation Administration (FAA) embarked on a program replacing older tube type electronic equipment with newer solid state equipment. This replacement program dramatically increased the susceptibility of the FAA's facilities to lightning related damages. The proposal is presented of techniques which may be employed to lessen the susceptibility of new FAA electronic facility designs to failures resulting from lightning related surges and transients as well as direct strikes. The general concept espoused is one of a consistent system approach employing both perimeter and internal protection. It compares the technique presently employed to reduce electronic noise with other techniques which reduce noise while lowering susceptibility to lightning related damage. It is anticipated that these techniques will be employed in the design of an Air Traffic Control Tower in a high isokeraunic area. This facility would be subjected to rigorous monitoring over a multi-year period to provide quantitative data hopefully supporting the advantage of this design.

Exploring the CAESAR database using dimensionality reduction techniques

NASA Astrophysics Data System (ADS)

Mendoza-Schrock, Olga; Raymer, Michael L.

2012-06-01

The Civilian American and European Surface Anthropometry Resource (CAESAR) database containing over 40 anthropometric measurements on over 4000 humans has been extensively explored for pattern recognition and classification purposes using the raw, original data [1-4]. However, some of the anthropometric variables would be impossible to collect in an uncontrolled environment. Here, we explore the use of dimensionality reduction methods in concert with a variety of classification algorithms for gender classification using only those variables that are readily observable in an uncontrolled environment. Several dimensionality reduction techniques are employed to learn the underlining structure of the data. These techniques include linear projections such as the classical Principal Components Analysis (PCA) and non-linear (manifold learning) techniques, such as Diffusion Maps and the Isomap technique. This paper briefly describes all three techniques, and compares three different classifiers, Naïve Bayes, Adaboost, and Support Vector Machines (SVM), for gender classification in conjunction with each of these three dimensionality reduction approaches.

PASCO: Structural panel analysis and sizing code: Users manual - Revised

NASA Technical Reports Server (NTRS)

Anderson, M. S.; Stroud, W. J.; Durling, B. J.; Hennessy, K. W.

1981-01-01

A computer code denoted PASCO is described for analyzing and sizing uniaxially stiffened composite panels. Buckling and vibration analyses are carried out with a linked plate analysis computer code denoted VIPASA, which is included in PASCO. Sizing is based on nonlinear mathematical programming techniques and employs a computer code denoted CONMIN, also included in PASCO. Design requirements considered are initial buckling, material strength, stiffness and vibration frequency. A user's manual for PASCO is presented.

Evaluation through research of a three-track career ladder program for registered nurses.

PubMed

Korman, Carol; Eliades, Aris Beoglos

2010-01-01

A descriptive study design was employed to survey registered nurse participants in a career ladder program comprising of three tracks: clinical, education, and management. Findings indicate that participation allows nurses of varying education preparation and roles to demonstrate professional development. Implications for staff development include efficacy of the online survey technique, provision of a reliable tool to evaluate a career ladder, and evaluation of a career ladder that includes the staff development educator.

Ground deformation monitoring using RADARSAT-2 DInSAR-MSBAS at the Aquistore CO2 storage site in Saskatchewan (Canada)

NASA Astrophysics Data System (ADS)

Czarnogorska, M.; Samsonov, S.; White, D.

2014-11-01

The research objectives of the Aquistore CO2 storage project are to design, adapt, and test non-seismic monitoring methods for measurement, and verification of CO2 storage, and to integrate data to determine subsurface fluid distributions, pressure changes and associated surface deformation. Aquistore site is located near Estevan in Southern Saskatchewan on the South flank of the Souris River and west of the Boundary Dam Power Station and the historical part of Estevan coal mine in southeastern Saskatchewan, Canada. Several monitoring techniques were employed in the study area including advanced satellite Differential Interferometric Synthetic Aperture Radar (DInSAR) technique, GPS, tiltmeters and piezometers. The targeted CO2 injection zones are within the Winnipeg and Deadwood formations located at > 3000 m depth. An array of monitoring techniques was employed in the study area including advanced satellite Differential Interferometric Synthetic Aperture Radar (DInSAR) with established corner reflectors, GPS, tiltmeters and piezometers stations. We used airborne LIDAR data for topographic phase estimation, and DInSAR product geocoding. Ground deformation maps have been calculated using Multidimensional Small Baseline Subset (MSBAS) methodology from 134 RADARSAT-2 images, from five different beams, acquired during 20120612-20140706. We computed and interpreted nine time series for selected places. MSBAS results indicate slow ground deformation up to 1 cm/year not related to CO2 injection but caused by various natural and anthropogenic causes.

Screw-Wire Osteo-Traction: An Adjunctive or Alternative Method of Anatomical Reduction of Multisegment Midfacial Fractures? A Description of Technique and Prospective Study of 40 Patients

PubMed Central

O'Regan, Barry; Devine, Maria; Bhopal, Sats

2013-01-01

Stable anatomical fracture reduction and segment control before miniplate fixation can be difficult to achieve in comminuted midfacial fractures. Fracture mobilization and reduction methods include Gillies elevation, malar hook, and Dingman elevators. No single method is used universally. Disadvantages include imprecise segment alignment and poor segment stability/control. We have employed screw-wire osteo-traction (SWOT) to address this problem. A literature review revealed two published reports. The aims were to evaluate the SWOT technique effectiveness as a fracture reduction method and to examine rates of revision fixation and plate removal. We recruited 40 consecutive patients requiring open reduction and internal fixation of multisegment midfacial fractures (2009–2012) and employed miniplate osteosynthesis in all patients. SWOT was used as a default reduction method in all patients. The rates of successful fracture reduction achieved by SWOT alone or in combination and of revision fixation and plate removal, were used as outcome indices of the reduction method effectiveness. The SWOT technique achieved satisfactory anatomical reduction in 27/40 patients when used alone. Other reduction methods were also used in 13/40 patients. No patient required revision fixation and three patients required late plate removal. SWOT can be used across the midface fracture pattern in conjunction with other methods or as a sole reduction method before miniplate fixation. PMID:24436763

The dynamics and control of large flexible space structures, 6

NASA Technical Reports Server (NTRS)

Bainum, P. M.

1983-01-01

The controls analysis based on a truncated finite element model of the 122m. Hoop/Column Antenna System focuses on an analysis of the controllability as well as the synthesis of control laws. Graph theoretic techniques are employed to consider controllability for different combinations of number and locations of actuators. Control law synthesis is based on an application of the linear regulator theory as well as pole placement techniques. Placement of an actuator on the hoop can result in a noticeable improvement in the transient characteristics. The problem of orientation and shape control of an orbiting flexible beam, previously examined, is now extended to include the influence of solar radiation environmental forces. For extremely flexible thin structures modification of control laws may be required and techniques for accomplishing this are explained. Effects of environmental torques are also included in previously developed models of orbiting flexible thin platforms.

Thermoelectrically cooled water trap

DOEpatents

Micheels, Ronald H [Concord, MA

2006-02-21

A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

Acoustic Liquid Manipulation Used to Enhance Electrochemical Processes

NASA Technical Reports Server (NTRS)

Oeftering, Richard C.

2005-01-01

Working in concert with the NASA Technology Transfer and Partnership Office, the Great Lakes Industrial Technology Center, and Alchemitron Corporation of Elgin, Illinois, the NASA Glenn Research Center has applied nonlinear acoustic principles to industrial applications. High-intensity ultrasonic beam techniques employ the effects of acoustic radiation pressure and acoustic streaming to manipulate the behavior of liquids. This includes propelling liquids, moving bubbles, and ejecting liquids as droplets and fountains. Since these effects can be accomplished without mechanical pumps or moving parts, we are exploring how these techniques could be used to manipulate liquids in space applications. Some of these acoustic techniques could be used both in normal Earth gravity and in the microgravity of space.

Anatomic partial nephrectomy: technique evolution.

PubMed

Azhar, Raed A; Metcalfe, Charles; Gill, Inderbir S

2015-03-01

Partial nephrectomy provides equivalent long-term oncologic and superior functional outcomes as radical nephrectomy for T1a renal masses. Herein, we review the various vascular clamping techniques employed during minimally invasive partial nephrectomy, describe the evolution of our partial nephrectomy technique and provide an update on contemporary thinking about the impact of ischemia on renal function. Recently, partial nephrectomy surgical technique has shifted away from main artery clamping and towards minimizing/eliminating global renal ischemia during partial nephrectomy. Supported by high-fidelity three-dimensional imaging, novel anatomic-based partial nephrectomy techniques have recently been developed, wherein partial nephrectomy can now be performed with segmental, minimal or zero global ischemia to the renal remnant. Sequential innovations have included early unclamping, segmental clamping, super-selective clamping and now culminating in anatomic zero-ischemia surgery. By eliminating 'under-the-gun' time pressure of ischemia for the surgeon, these techniques allow an unhurried, tightly contoured tumour excision with point-specific sutured haemostasis. Recent data indicate that zero-ischemia partial nephrectomy may provide better functional outcomes by minimizing/eliminating global ischemia and preserving greater vascularized kidney volume. Contemporary partial nephrectomy includes a spectrum of surgical techniques ranging from conventional-clamped to novel zero-ischemia approaches. Technique selection should be tailored to each individual case on the basis of tumour characteristics, surgical feasibility, surgeon experience, patient demographics and baseline renal function.

Theoretical considerations and a simple method for measuring alkalinity and acidity in low-pH waters by gran titration

USGS Publications Warehouse

Barringer, J.L.; Johnsson, P.A.

1996-01-01

Titrations for alkalinity and acidity using the technique described by Gran (1952, Determination of the equivalence point in potentiometric titrations, Part II: The Analyst, v. 77, p. 661-671) have been employed in the analysis of low-pH natural waters. This report includes a synopsis of the theory and calculations associated with Gran's technique and presents a simple and inexpensive method for performing alkalinity and acidity determinations. However, potential sources of error introduced by the chemical character of some waters may limit the utility of Gran's technique. Therefore, the cost- and time-efficient method for performing alkalinity and acidity determinations described in this report is useful for exploring the suitability of Gran's technique in studies of water chemistry.

Modified Labial Button Technique for Maintaining Occlusion After Caudal Mandibular Fracture/Temporomandibular Joint Luxation in the Cat.

PubMed

Goodman, Alice E; Carmichael, Daniel T

2016-03-01

Maxillofacial trauma in cats often results in mandibular symphyseal separation in addition to injuries of the caudal mandible and/or temporomandibular joint (TMJ). Caudal mandibular and TMJ injuries are difficult to access and stabilize using direct fixation techniques, thus indirect fixation is commonly employed. The immediate goals of fixation include stabilization for return to normal occlusion and function with the long-term objective of bony union. Indirect fixation techniques commonly used for stabilization of caudal mandibular and temporomandibular joint fracture/luxation include maxillomandibular fixation (MMF) with acrylic composite, interarcade wiring, tape muzzles, and the bignathic encircling and retaining device (BEARD) technique. This article introduces a modification of the previously described "labial reverse suture through buttons" technique used by Koestlin et al and the "labial locking with buttons" technique by Rocha et al. In cases with minimally displaced subcondylar and pericondylar fractures without joint involvement, the labial button technique can provide sufficient stabilization for healing. Advantages of the modified labial button technique include ease of application, noninvasive nature, and use of readily available materials. The construct can remain in place for a variable of amount of time, depending on its intended purpose. It serves as an alternative to the tape muzzle, which is rarely tolerated by cats. This technique can be easily used in conjunction with other maxillomandibular repairs, such as cerclage wire fixation of mandibular symphyseal separation. The purpose of this article is to demonstrate a modified labial button technique for maintaining occlusion of feline caudal mandibular fractures/TMJ luxations in a step-by-step fashion.

Pulsed field probe of real time magnetization dynamics in magnetic nanoparticle systems

NASA Astrophysics Data System (ADS)

Foulkes, T.; Syed, M.; Taplin, T.

2015-05-01

Magnetic nanoparticles (MNPs) are extensively used in biotechnology. These applications rely on magnetic properties that are a keen function of MNP size, distribution, and shape. Various magneto-optical techniques, including Faraday Rotation (FR), Cotton-Mouton Effect, etc., have been employed to characterize magnetic properties of MNPs. Generally, these measurements employ AC or DC fields. In this work, we describe the results from a FR setup that uses pulsed magnetic fields and an analysis technique that makes use of the entire pulse shape to investigate size distribution and shape anisotropy. The setup employs a light source, polarizing components, and a detector that are used to measure the rotation of light from a sample that is subjected to a pulsed magnetic field. This magnetic field "snapshot" is recorded alongside the intensity pulse of the sample's response. This side by side comparison yields useful information about the real time magnetization dynamics of the system being probed. The setup is highly flexible with variable control of pulse length and peak magnitude. Examining the raw data for the response of bare Fe3O4 and hybrid Au and Fe3O4 nanorods reveals interesting information about Brownian relaxation and the hydrodynamic size of these nanorods. This analysis exploits the self-referencing nature of this measurement to highlight the impact of an applied field on creating a field induced transparency for a longitudinal measurement. Possible sources for this behavior include shape anisotropy and field assisted aggregate formation.

Military Police Operations and Counterinsurgency

DTIC Science & Technology

2008-03-01

that deceitfully advertised PRUs as assassination squads. In reality most PRU operations ended in the successful capture and prosecution of VCI...and neutralize Kimathi whose capture " virtually ended Mau Mau resistence" (Asprey, 886). This campaign analysis will use the following categories to...for special access programs. , 3.10. Employs specialized investigative techniques to include forensic and t:>ehavioral sciencell and hypnosis . 3.11

Understanding Thermal Transport in Graded, Layered and Hybrid Materials

DTIC Science & Technology

2014-04-01

interfacial chemistries, including metallic and carbide layers, and; (iv) mimic the observed interface structure on a TDTR specimen by manipulating the...surface carbides , which were extracted from several different composites via acid dissolution of Cu, continued throughout the last 12 months of the...effort. The previously-reported electron probe microanalysis (EPMA) based techniques were employed to estimate the interfacial carbide layer thickness

No Evidence of Suicide Increase Following Terrorist Attacks in the United States: An Interrupted Time-Series Analysis of September 11 and Oklahoma City

ERIC Educational Resources Information Center

Pridemore, William Alex; Trahan, Adam; Chamlin, Mitchell B.

2009-01-01

There is substantial evidence of detrimental psychological sequelae following disasters, including terrorist attacks. The effect of these events on extreme responses such as suicide, however, is unclear. We tested competing hypotheses about such effects by employing autoregressive integrated moving average techniques to model the impact of…

Development of Regional Wind Resource and Wind Plant Output Datasets for the Hawaiian Islands

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

Manobianco, J.; Alonge, C.; Frank, J.

In March 2009, AWS Truepower was engaged by the National Renewable Energy Laboratory (NREL) to develop a set of wind resource and plant output data for the Hawaiian Islands. The objective of this project was to expand the methods and techniques employed in the Eastern Wind Integration and Transmission Study (EWITS) to include the state of Hawaii.

Using nonlinear quantile regression to estimate the self-thinning boundary curve

Treesearch

Quang V. Cao; Thomas J. Dean

2015-01-01

The relationship between tree size (quadratic mean diameter) and tree density (number of trees per unit area) has been a topic of research and discussion for many decades. Starting with Reineke in 1933, the maximum size-density relationship, on a log-log scale, has been assumed to be linear. Several techniques, including linear quantile regression, have been employed...

A Study of Pre-Service Classroom Teachers' Beliefs about Teachers' and Students' Roles

ERIC Educational Resources Information Center

Kögce, Davut

2017-01-01

The aim of this study is to determine pre-service classroom teachers' beliefs and thoughts about the roles of teachers and students in the classroom before taking the Mathematics Teaching I course. With this purpose, the study employed the survey method, a descriptive research technique. The study sample included 75 pre-service teachers (55…

Reflections on Recruiting, Supporting, Retaining, Graduating, and Obtaining Employment for Doctoral Students from Diverse Backgrounds

ERIC Educational Resources Information Center

Dieker, Lisa; Wienke, Wilfred; Straub, Carrie; Finnegan, Lisa

2014-01-01

In this article, the authors provide a summary of the current techniques being used to recruit, retain, and support a diverse range of scholars, including students with disabilities, in a doctoral program. The manuscript provides a summary of the current need for leadership personnel who are scholars with knowledge in special education, general…

Working with Organizations to Develop "New Careers" Programs. Technical Monograph No. 10, Publication No. 110.

ERIC Educational Resources Information Center

Pruger, Robert; Specht, Harry

This report on a job creation program for poor people deals with the organizations within which jobs were created, the responses of the organizations to the jobs, and the techniques which seemed useful in working with the organizations. Major sections include: (1) Employment, Unemployment and New Careers, (2) Organizational Barriers, (3) The Forms…

Hierarchy of simulation models for a turbofan gas engine

NASA Technical Reports Server (NTRS)

Longenbaker, W. E.; Leake, R. J.

1977-01-01

Steady-state and transient performance of an F-100-like turbofan gas engine are modeled by a computer program, DYNGEN, developed by NASA. The model employs block data maps and includes about 25 states. Low-order nonlinear analytical and linear techniques are described in terms of their application to the model. Experimental comparisons illustrating the accuracy of each model are presented.

Strain-gage bridge calibration and flight loads measurements on a low-aspect-ratio thin wing

NASA Technical Reports Server (NTRS)

Peele, E. L.; Eckstrom, C. V.

1975-01-01

Strain-gage bridges were used to make in-flight measurements of bending moment, shear, and torque loads on a low-aspect-ratio, thin, swept wing having a full depth honeycomb sandwich type structure. Standard regression analysis techniques were employed in the calibration of the strain bridges. Comparison of the measured loads with theoretical loads are included.

Breaking the Silence on Domestic Violence: Information for Children's Services Workers. Australian Early Childhood Resource Booklets No. 3.

ERIC Educational Resources Information Center

McGregor, Heather

This booklet is designed to provide Australian early childhood workers with information about domestic violence and response techniques to employ if they become aware that children under their care are witnessing domestic violence. The booklet notes that domestic violence can include physical and sexual violence, as well as psychological, social,…

Results of Survey for 1975-76 on Labor Market for Handicapped Persons in Manatee and Sarasota Counties.

ERIC Educational Resources Information Center

Florida Learning Resources System/Suncoast Associate Center, Sarasota.

Presented are the results of a survey involving personnel directors from 271 local firms in Manatee and Sarasota Counties (Florida) on the employment of the physically impaired, visually impaired, hearing impaired, and mentally retarded. Included are brief descriptions of the goals of the survey and the sampling technique used, and a sample survey…

Methods of Oil Detection in Response to the Deepwater ...

EPA Pesticide Factsheets

Detecting oil in the northern Gulf of Mexico following the Deepwater Horizon oil spill presented unique challenges due to the spatial and temporal extent of the spill and the subsequent dilution of oil in the environment. Over time, physical, chemical, and biological processes altered the composition of the oil, further complicating its detection. Reservoir fluid, containing gas and oil, released from the Macondo well was detected in surface and subsurface environments. Oil monitoring during and after the spill required a variety of technologies, including nimble adaptation of techniques developed for non-oil-related applications. The oil detection technologies employed varied in sensitivity, selectivity, strategy, cost, usability, expertise of user, and reliability. Innovative technologies ranging from remote sensing to laboratory analytical techniques were employed and produced new information relevant to oil spill detection, including the chemical characterization, the dispersion effectiveness, and the detection limits of oil. The challenge remains to transfer these new technologies to oil spill responders so that detection of oil following a spill can be improved. To publish a perspective paper on oil detection technologies during the Deepwater Horizon Oil Spill. This is for a special issue book/journal.

Elimination of sulphur odours at landfills by bioconversion and the corona discharge plasma technique.

PubMed

Xia, Fangfang; Liu, Xin; Kang, Ying; He, Ruo; Wu, Zucheng

2015-01-01

Hydrogen sulphide (H2S) contributes a lot to odours at landfills, which is a threat to the environment and the health of the staff therein. To mitigate its emission, the bioconversion within landfill cover soils (LCSs) was introduced. H2S emission and concentration both in the field air above the landfill and in microcosm testing were surveyed. Results indicated that H2S emission and concentration in the landfill varied with landfill seasons and sites. There existed relationship between H2S concentration and fluxes spatially and temporally. To characterize and assess the spatial and temporal diversity of sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) in the LCSs, the terminal-restriction fragment length polymorphism technique was employed. Using the functional genes of dsrB and soxB, SOB, including Halothiobacillus, Rhodothalassium, Paracocccus, Allochromatium, and Thiobacillus, and SRB, including Desulfovibrio, Syntrophobacter, Desulfomonile and Desulfobacca, were identical and exhibited the dominant role in the LCSs. By employing an alternative available corona reactor, more than 90% removal efficiencies of sulphides were demonstrated, suggesting that the LCSs for eliminating odours in a lower concentration would be feasible.

Porous silicon - rare earth doped xerogel and glass composites

NASA Astrophysics Data System (ADS)

Balakrishnan, S.; Gun'ko, Yurii K.; Perova, T. S.; Rafferty, A.; Astrova, E. V.; Moore, R. A.

2005-06-01

The development of components for photonics applications is growing exponentially. The sol-gel method is now recognised as a convenient and flexible way to deposit oxide or glass films on a variety of hosts, including porous silicon. In the present work we incorporated erbium and europium doped xerogel into porous silicon and developed new porous silicon - rare earth doped glass composites. Various characteris-ation techniques including FTIR, Raman Spectroscopy, Thermal Gravimetric Analysis and Scanning Electron Microscopy were employed in this work.

Optimization of a point-focusing, distributed receiver solar thermal electric system

NASA Technical Reports Server (NTRS)

Pons, R. L.

1979-01-01

This paper presents an approach to optimization of a solar concept which employs solar-to-electric power conversion at the focus of parabolic dish concentrators. The optimization procedure is presented through a series of trade studies, which include the results of optical/thermal analyses and individual subsystem trades. Alternate closed-cycle and open-cycle Brayton engines and organic Rankine engines are considered to show the influence of the optimization process, and various storage techniques are evaluated, including batteries, flywheels, and hybrid-engine operation.

Contrast-enhanced peripheral MRA: technique and contrast agents.

PubMed

Nielsen, Yousef W; Thomsen, Henrik S

2012-09-01

In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X-ray angiography.

A Survey of Terrestrial Approaches to the Challenge of Lunar Dust Containment

NASA Technical Reports Server (NTRS)

Aguilera, Tatiana; Perry, Jay L.

2009-01-01

Numerous technical challenges exist to successfully extend lunar surface exploration beyond the tantalizing first steps of Apollo. Among these is the challenge of lunar dust intrusion into the cabin environment. Addressing this challenge includes the design of barriers to intrusion as well as techniques for removing the dust from the cabin atmosphere. Opportunities exist for adapting approaches employed in dusty industrial operations and pristine manufacturing environments to cabin environmental quality maintenance applications. A survey of process technologies employed by the semiconductor, pharmaceutical, food processing, and mining industries offers insight into basic approaches that may be suitable for adaptation to lunar surface exploration applications.

Generic results of the space physics community survey

NASA Technical Reports Server (NTRS)

Sharma, Rikhi R.; Cohen, Nathaniel B.

1993-01-01

This report summarizes the results of a survey of the members of the space physics research community conducted in 1990-1991 to ascertain demographic information on the respondents and information on their views on a number of facets of their space physics research. The survey was conducted by questionnaire and the information received was compiled in a database and analyzed statistically. The statistical results are presented for the respondent population as a whole and by four different respondent cross sections: individual disciplines of space physics, type of employers, age groups, and research techniques employed. Data from a brief corresponding survey of the graduate students of respondents are also included.

Collaborative Software Development in Support of Fast Adaptive AeroSpace Tools (FAAST)

NASA Technical Reports Server (NTRS)

Kleb, William L.; Nielsen, Eric J.; Gnoffo, Peter A.; Park, Michael A.; Wood, William A.

2003-01-01

A collaborative software development approach is described. The software product is an adaptation of proven computational capabilities combined with new capabilities to form the Agency's next generation aerothermodynamic and aerodynamic analysis and design tools. To efficiently produce a cohesive, robust, and extensible software suite, the approach uses agile software development techniques; specifically, project retrospectives, the Scrum status meeting format, and a subset of Extreme Programming's coding practices are employed. Examples are provided which demonstrate the substantial benefits derived from employing these practices. Also included is a discussion of issues encountered when porting legacy Fortran 77 code to Fortran 95 and a Fortran 95 coding standard.

Nonholonomic Hamiltonian Method for Meso-macroscale Simulations of Reacting Shocks

NASA Astrophysics Data System (ADS)

Fahrenthold, Eric; Lee, Sangyup

2015-06-01

The seamless integration of macroscale, mesoscale, and molecular scale models of reacting shock physics has been hindered by dramatic differences in the model formulation techniques normally used at different scales. In recent research the authors have developed the first unified discrete Hamiltonian approach to multiscale simulation of reacting shock physics. Unlike previous work, the formulation employs reacting themomechanical Hamiltonian formulations at all scales, including the continuum. Unlike previous work, the formulation employs a nonholonomic modeling approach to systematically couple the models developed at all scales. Example applications of the method show meso-macroscale shock to detonation simulations in nitromethane and RDX. Research supported by the Defense Threat Reduction Agency.

The 1064 nm laser-induced breakdown spectroscopy (LIBS) inspection to detect the nutrient elements in freshly cut carrot samples

NASA Astrophysics Data System (ADS)

Yudasari, N.; Prasetyo, S.; Suliyanti, M. M.

2018-03-01

The laser-induced breakdown spectroscopy (LIBS) technique was applied to detect the nutrient elements contained in fresh carrot. Nd:YAG laser the wavelength of 1064 nm was employed in the experiments for ablation. Employing simple set-up of LIBS and preparing the sample with less step method, we are able to detect 18 chemical elements including some fundamental element of carrot, i.e Mg, Al, Fe, Mn, Ti, Ca, and Mn. By applying normalized profiles calculation on some of the element, we are able to compare the concentration level of each element of the outer and inner part of carrot.

Measurement of trace stratospheric constituents with a balloon borne laser radar

NASA Technical Reports Server (NTRS)

Heaps, William S.; Mcgee, Thomas J.

1990-01-01

The objective of this research was to measure the concentration of the stratospheric hydroxyl radical and related chemical species as a function of altitude, season, and time of day. Although hydroxyl plays a very important role in the chemistry controlling stratospheric ozone, little is known about its behavior because it has been a difficult species to measure. The instrument employed in this program was a laser radar, employing the technique of remote laser induced fluorescence. This instrument offers a number of attractive features including extreme specificity and sensitivity, a straightforward relationship between observed quantity and the desired concentration, and immunity to self-contamination.

Application of Fiber-Optical Techniques in the Access Transmission and Backbone Transport of Mobile Networks

NASA Astrophysics Data System (ADS)

Hilt, Attila; Pozsonyi, László

2012-09-01

Fixed access networks widely employ fiber-optical techniques due to the extremely wide bandwidth offered to subscribers. In the last decade, there has also been an enormous increase of user data visible in mobile systems. The importance of fiber-optical techniques within the fixed transmission/transport networks of mobile systems is therefore inevitably increasing. This article summarizes a few reasons and gives examples why and how fiber-optic techniques are employed efficiently in second-generation networks.

Effects of high energy radiation on the mechanical properties of epoxy-graphite fiber reinforced composites

NASA Technical Reports Server (NTRS)

Fornes, R. E.; Gilbert, R. D.; Memory, J. D.

1984-01-01

The effects of high energy radiation on the mechanical properties and on the molecular and structural properties of graphite fiber reinforced composites were assessed so that the durability of such composites in space applications could be predicted. Investigative techniques including ESR and infrared spectroscopy, ESCA, contact angle measurements, and dynamic and static mechanical testing (3-point bending and interlaminar shear) were employed. The results using these different techniques are individually described, and the implications of the data are discussed. The proposed plan of work for the next fiscal year is outlined.

Calculation of compressible flow about three-dimensional inlets with auxiliary inlets, slats and vanes by means of a panel method

NASA Technical Reports Server (NTRS)

Hess, J. L.; Friedman, D. M.; Clark, R. W.

1985-01-01

An efficient and user oriented method was constructed for calculating flow in and about complex inlet configurations. Efficiency is attained by: (1) the use of a panel method; (2) a technique of superposition for obtaining solutions at any inlet operating condition; and (3) employment of an advanced matrix iteration technique for solving large full systems of equations, including the nonlinear equations for the Kutta condition. User concerns are addressed by the provision of several novel graphical output options that yield a more complete comprehension of the flowfield than was possible previously.

Taenia asiatica: the most neglected human Taenia and the possibility of cysticercosis.

PubMed

Galán-Puchades, M Teresa; Fuentes, Mario V

2013-02-01

Not only Taenia solium and Taenia saginata, but also Taenia asiatica infects humans. The last species is not included in the evaluation of the specificity of the immunodiagnostic techniques for taeniasis/cysticercosis. There is currently no specific immunodiagnostic method for T. asiatica available. Therefore, due to the fact that molecular techniques (the only tool to distinguish the 3 Taenia species) are normally not employed in routine diagnostic methods, the 2 questions concerning T. asiatica (its definite geographic distribution and its ability to cause human cysticercosis), remain open, turning T. asiatica into the most neglected agent of human taeniasis-cysticercosis.

Photobiomolecular deposition of metallic particles and films

DOEpatents

Hu, Zhong-Cheng

2005-02-08

The method of the invention is based on the unique electron-carrying function of a photocatalytic unit such as the photosynthesis system I (PSI) reaction center of the protein-chlorophyll complex isolated from chloroplasts. The method employs a photo-biomolecular metal deposition technique for precisely controlled nucleation and growth of metallic clusters/particles, e.g., platinum, palladium, and their alloys, etc., as well as for thin-film formation above the surface of a solid substrate. The photochemically mediated technique offers numerous advantages over traditional deposition methods including quantitative atom deposition control, high energy efficiency, and mild operating condition requirements.

Photobiomolecular metallic particles and films

DOEpatents

Hu, Zhong-Cheng

2003-05-06

The method of the invention is based on the unique electron-carrying function of a photocatalytic unit such as the photosynthesis system I (PSI) reaction center of the protein-chlorophyll complex isolated from chloroplasts. The method employs a photo-biomolecular metal deposition technique for precisely controlled nucleation and growth of metallic clusters/particles, e.g., platinum, palladium, and their alloys, etc., as well as for thin-film formation above the surface of a solid substrate. The photochemically mediated technique offers numerous advantages over traditional deposition methods including quantitative atom deposition control, high energy efficiency, and mild operating condition requirements.

First Approximations of Prescribed Fire Risks Relative to Other Management Techniques Used on Private Lands.

PubMed

Twidwell, Dirac; Wonkka, Carissa L; Sindelar, Michael T; Weir, John R

2015-01-01

Fire is widely recognized as a critical ecological and evolutionary driver that needs to be at the forefront of land management actions if conservation targets are to be met. However, the prevailing view is that prescribed fire is riskier than other land management techniques. Perceived risks associated with the application of fire limits its use and reduces agency support for prescribed burning in the private sector. As a result, considerably less cost-share support is given for prescribed fire compared to mechanical techniques. This study tests the general perception that fire is a riskier technique relative to other land management options. Due to the lack of data available to directly test this notion, we use a combination of approaches including 1) a comparison of fatalities resulting from different occupations that are proxies for techniques employed in land management, 2) a comparison of fatalities resulting from wildland fire versus prescribed fire, and 3) an exploration of causal factors responsible for wildland fire-related fatalities. This approach establishes a first approximation of the relative risk of fatality to private citizens using prescribed fire compared to other management techniques that are readily used in ecosystem management. Our data do not support using risks of landowner fatalities as justification for the use of alternative land management techniques, such as mechanical (machine-related) equipment, over prescribed fire. Vehicles and heavy machinery are consistently leading reasons for fatalities within occupations selected as proxies for management techniques employed by ranchers and agricultural producers, and also constitute a large proportion of fatalities among firefighters. Our study provides the foundation for agencies to establish data-driven decisions regarding the degree of support they provide for prescribed burning on private lands.

First Approximations of Prescribed Fire Risks Relative to Other Management Techniques Used on Private Lands

PubMed Central

Twidwell, Dirac; Wonkka, Carissa L.; Sindelar, Michael T.; Weir, John R.

2015-01-01

Fire is widely recognized as a critical ecological and evolutionary driver that needs to be at the forefront of land management actions if conservation targets are to be met. However, the prevailing view is that prescribed fire is riskier than other land management techniques. Perceived risks associated with the application of fire limits its use and reduces agency support for prescribed burning in the private sector. As a result, considerably less cost-share support is given for prescribed fire compared to mechanical techniques. This study tests the general perception that fire is a riskier technique relative to other land management options. Due to the lack of data available to directly test this notion, we use a combination of approaches including 1) a comparison of fatalities resulting from different occupations that are proxies for techniques employed in land management, 2) a comparison of fatalities resulting from wildland fire versus prescribed fire, and 3) an exploration of causal factors responsible for wildland fire-related fatalities. This approach establishes a first approximation of the relative risk of fatality to private citizens using prescribed fire compared to other management techniques that are readily used in ecosystem management. Our data do not support using risks of landowner fatalities as justification for the use of alternative land management techniques, such as mechanical (machine-related) equipment, over prescribed fire. Vehicles and heavy machinery are consistently leading reasons for fatalities within occupations selected as proxies for management techniques employed by ranchers and agricultural producers, and also constitute a large proportion of fatalities among firefighters. Our study provides the foundation for agencies to establish data-driven decisions regarding the degree of support they provide for prescribed burning on private lands. PMID:26465329

Installation effects on the tonal noise generated by axial flow fans

NASA Astrophysics Data System (ADS)

Canepa, Edward; Cattanei, Andrea; Mazzocut Zecchin, Fabio

2015-03-01

The paper presents the results of experiments on a low-speed axial-flow fan flush mounted on flat panels typically employed in tests on automotive cooling fans. The experiments have been conducted in a hemi-anechoic chamber and were aimed at evaluating the installation effects of the whole test configuration, including chamber floor and size and shape of the mounting panel. The largest panels cause important SPL variations in a narrow, low frequency range. Their effect on the propagation function has been verified by means of parametric BEM computations. A regular wavy trend associated with reflections from the floor is also present. In both cases, the tonal noise is more strongly affected than the broadband one. The analysis is performed by means of an existing spectral decomposition technique and a new one, which allows to consider different noise generating mechanisms and also to separate the emitted tonal and broadband noise from the associated propagation effects. In order to better identify the features of the noise at the blade passing frequency (BPF) harmonics, the phase of the acoustic pressure is also analysed. Measurements are taken during speed ramps, which allow to obtain both constant-Strouhal number SPL data and constant-speed data. The former data set is employed in the new technique, while the latter may be employed in the standard spectral decomposition techniques. Based on both the similarity theory and the analysis of the Green's function of the problem, a theoretical description of the structure of the received SPL spectrum is given. Then, the possibility of discriminating between tonal and broadband noise generating mechanisms is analysed and a theoretical base for the new spectral decomposition technique is provided.

Accounting for large deformations in real-time simulations of soft tissues based on reduced-order models.

PubMed

Niroomandi, S; Alfaro, I; Cueto, E; Chinesta, F

2012-01-01

Model reduction techniques have shown to constitute a valuable tool for real-time simulation in surgical environments and other fields. However, some limitations, imposed by real-time constraints, have not yet been overcome. One of such limitations is the severe limitation in time (established in 500Hz of frequency for the resolution) that precludes the employ of Newton-like schemes for solving non-linear models as the ones usually employed for modeling biological tissues. In this work we present a technique able to deal with geometrically non-linear models, based on the employ of model reduction techniques, together with an efficient non-linear solver. Examples of the performance of the technique over some examples will be given. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Optimization of a chemical identification algorithm

NASA Astrophysics Data System (ADS)

Chyba, Thomas H.; Fisk, Brian; Gunning, Christin; Farley, Kevin; Polizzi, Amber; Baughman, David; Simpson, Steven; Slamani, Mohamed-Adel; Almassy, Robert; Da Re, Ryan; Li, Eunice; MacDonald, Steve; Slamani, Ahmed; Mitchell, Scott A.; Pendell-Jones, Jay; Reed, Timothy L.; Emge, Darren

2010-04-01

A procedure to evaluate and optimize the performance of a chemical identification algorithm is presented. The Joint Contaminated Surface Detector (JCSD) employs Raman spectroscopy to detect and identify surface chemical contamination. JCSD measurements of chemical warfare agents, simulants, toxic industrial chemicals, interferents and bare surface backgrounds were made in the laboratory and under realistic field conditions. A test data suite, developed from these measurements, is used to benchmark algorithm performance throughout the improvement process. In any one measurement, one of many possible targets can be present along with interferents and surfaces. The detection results are expressed as a 2-category classification problem so that Receiver Operating Characteristic (ROC) techniques can be applied. The limitations of applying this framework to chemical detection problems are discussed along with means to mitigate them. Algorithmic performance is optimized globally using robust Design of Experiments and Taguchi techniques. These methods require figures of merit to trade off between false alarms and detection probability. Several figures of merit, including the Matthews Correlation Coefficient and the Taguchi Signal-to-Noise Ratio are compared. Following the optimization of global parameters which govern the algorithm behavior across all target chemicals, ROC techniques are employed to optimize chemical-specific parameters to further improve performance.

Bounding solutions of geometrically nonlinear viscoelastic problems

NASA Technical Reports Server (NTRS)

Stubstad, J. M.; Simitses, G. J.

1985-01-01

Integral transform techniques, such as the Laplace transform, provide simple and direct methods for solving viscoelastic problems formulated within a context of linear material response and using linear measures for deformation. Application of the transform operator reduces the governing linear integro-differential equations to a set of algebraic relations between the transforms of the unknown functions, the viscoelastic operators, and the initial and boundary conditions. Inversion either directly or through the use of the appropriate convolution theorem, provides the time domain response once the unknown functions have been expressed in terms of sums, products or ratios of known transforms. When exact inversion is not possible approximate techniques may provide accurate results. The overall problem becomes substantially more complex when nonlinear effects must be included. Situations where a linear material constitutive law can still be productively employed but where the magnitude of the resulting time dependent deformations warrants the use of a nonlinear kinematic analysis are considered. The governing equations will be nonlinear integro-differential equations for this class of problems. Thus traditional as well as approximate techniques, such as cited above, cannot be employed since the transform of a nonlinear function is not explicitly expressible.

Bounding solutions of geometrically nonlinear viscoelastic problems

NASA Technical Reports Server (NTRS)

Stubstad, J. M.; Simitses, G. J.

1986-01-01

Integral transform techniques, such as the Laplace transform, provide simple and direct methods for solving viscoelastic problems formulated within a context of linear material response and using linear measures for deformation. Application of the transform operator reduces the governing linear integro-differential equations to a set of algebraic relations between the transforms of the unknown functions, the viscoelastic operators, and the initial and boundary conditions. Inversion either directly or through the use of the appropriate convolution theorem, provides the time domain response once the unknown functions have been expressed in terms of sums, products or ratios of known transforms. When exact inversion is not possible approximate techniques may provide accurate results. The overall problem becomes substantially more complex when nonlinear effects must be included. Situations where a linear material constitutive law can still be productively employed but where the magnitude of the resulting time dependent deformations warrants the use of a nonlinear kinematic analysis are considered. The governing equations will be nonlinear integro-differential equations for this class of problems. Thus traditional as well as approximate techniques, such as cited above, cannot be employed since the transform of a nonlinear function is not explicitly expressible.

Decision rules for unbiased inventory estimates

NASA Technical Reports Server (NTRS)

Argentiero, P. D.; Koch, D.

1979-01-01

An efficient and accurate procedure for estimating inventories from remote sensing scenes is presented. In place of the conventional and expensive full dimensional Bayes decision rule, a one-dimensional feature extraction and classification technique was employed. It is shown that this efficient decision rule can be used to develop unbiased inventory estimates and that for large sample sizes typical of satellite derived remote sensing scenes, resulting accuracies are comparable or superior to more expensive alternative procedures. Mathematical details of the procedure are provided in the body of the report and in the appendix. Results of a numerical simulation of the technique using statistics obtained from an observed LANDSAT scene are included. The simulation demonstrates the effectiveness of the technique in computing accurate inventory estimates.

Pump-probe optical microscopy for imaging nonfluorescent chromophores.

PubMed

Wei, Lu; Min, Wei

2012-06-01

Many chromophores absorb light intensely but have undetectable fluorescence. Hence microscopy techniques other than fluorescence are highly desirable for imaging these chromophores inside live cells, tissues, and organisms. The recently developed pump-probe optical microscopy techniques provide fluorescence-free contrast mechanisms by employing several fundamental light-molecule interactions including excited state absorption, stimulated emission, ground state depletion, and the photothermal effect. By using the pump pulse to excite molecules and the subsequent probe pulse to interrogate the created transient states on a laser scanning microscope, pump-probe microscopy offers imaging capability with high sensitivity and specificity toward nonfluorescent chromophores. Single-molecule sensitivity has even been demonstrated. Here we review and summarize the underlying principles of this emerging class of molecular imaging techniques.

Surface analysis of space telescope material specimens

NASA Technical Reports Server (NTRS)

Fromhold, A. T.; Daneshvar, K.

1985-01-01

Qualitative and quantitative data on Space Telescope materials which were exposed to low Earth orbital atomic oxygen in a controlled experiment during the 41-G (STS-17) mission were obtained utilizing the experimental techniques of Rutherford backscattering (RBS), particle induced X-ray emission (PIXE), and ellipsometry (ELL). The techniques employed were chosen with a view towards appropriateness for the sample in question, after consultation with NASA scientific personnel who provided the material specimens. A group of eight samples and their controls selected by NASA scientists were measured before and after flight. Information reported herein include specimen surface characterization by ellipsometry techniques, a determination of the thickness of the evaporated metal specimens by RBS, and a determination of trace impurity species present on and within the surface by PIXE.

Managing age discrimination: an examination of the techniques used when seeking employment.

PubMed

Berger, Ellie D

2009-06-01

This article examines the age-related management techniques used by older workers in their search for employment. Data are drawn from interviews with individuals aged 45-65 years (N = 30). Findings indicate that participants develop "counteractions" and "concealments" to manage perceived age discrimination. Individuals counteract employers' ageist stereotypes by maintaining their skills and changing their work-related expectations and conceal age by altering their résumés, physical appearance, and language used. This research suggests that there is a need to reexamine the hiring practices of employers and to improve legislation in relation to their accountability.

How can the rehabilitation planning process at the workplace be improved? A qualitative study from employers' perspective.

PubMed

Larsson, Agneta; Gard, Gunvor

2003-09-01

Employers in Sweden are by law responsible for planning and controlling the working environment situation in their companies and for ensuring that any need for rehabilitation is noted as soon as possible and that action is taken. This includes developing a plan for rehabilitation. The aim of this study is to describe employers' experiences of the work rehabilitation planning process at the workplace, and how it can be improved with a focus on quality and cost-effectiveness. Qualitative interviews were performed with 10 employers of employee/s that had participated in vocational rehabilitation at a rehabilitation center in the North of Sweden. The results showed that employers were interested in detecting work rehabilitation needs and in taking action early. Rehabilitation at the workplace could be improved by development of routines, improved work relations and work technique, and environment in-service training at the workplace. Prevention was perceived as a prerequisite for a good result of rehabilitation. Attention to social and geographic conditions is needed. Organizational and financial limitations exist.

Video methods in the quantification of children's exposures.

PubMed

Ferguson, Alesia C; Canales, Robert A; Beamer, Paloma; Auyeung, Willa; Key, Maya; Munninghoff, Amy; Lee, Kevin Tse-Wing; Robertson, Alexander; Leckie, James O

2006-05-01

In 1994, Stanford University's Exposure Research Group (ERG) conducted its first pilot study to collect micro-level activity time series (MLATS) data for young children. The pilot study involved videotaping four children of farm workers in the Salinas Valley of California and converting their videotaped activities to valuable text files of contact behavior using video-translation techniques. These MLATS are especially useful for describing intermittent dermal (i.e., second-by-second account of surfaces and objects contacted) and non-dietary ingestion (second-by-second account of objects or hands placed in the mouth) contact behavior. Second-by-second records of children contact behavior are amenable to quantitative and statistical analysis and allow for more accurate model estimates of human exposure and dose to environmental contaminants. Activity patterns data for modeling inhalation exposure (i.e., accounts of microenvironments visited) can also be extracted from the MLATS data. Since the pilot study, ERG has collected an immense MLATS data set for 92 children using more developed and refined videotaping and video-translation methodologies. This paper describes all aspects required for the collection of MLATS including: subject recruitment techniques, videotaping and video-translation processes, and potential data analysis. This paper also describes the quality assurance steps employed for these new MLATS projects, including: training, data management, and the application of interobserver and intraobserver agreement during video translation. The discussion of these issues and ERG's experiences in dealing with them can assist other groups in the conduct of research that employs these more quantitative techniques.

Application of infrared techniques to the study of atmospheric ozone

NASA Astrophysics Data System (ADS)

Secroun, C.; Barbe, A.; Marche, P.; Jouve, P.

The present investigation is concerned with the utilization of the infrared wavelength region for the study of the ozone in the atmosphere, taking into account three atmospheric windows including the wavelength ranges near 10, 5, and 3 micrometers. More than 3200 spectral lines could be assigned to different bands of the ozone spectrum. Laboratory studies formed one part of the investigation. Spectral frequencies, absorption line intensities, and linewidths were determined for ozone. Some of the obtained results were employed in connection with data provided by the radiometric probe LIMS on board the Nimbus-7 satellite. The second part of the investigation involved a study of the atmosphere. The same spectrometer as in the laboratory study was utilized, and the sun was employed as radiation source. The obtained results were compared with data provided by a Dobson spectrophotometer. Attention is also given to vertical concentration profiles. It is concluded that infrared absorption spectroscopy represents a suitable technique for studies of atmospheric ozone.

Synthesis of a fine neurological electrode by plasma polymerization processing.

PubMed

Cannon, J G; Dillon, R O; Bunshah, R F; Crandall, P H; Dymond, A M

1980-05-01

This research is part of a continuing program for the development of a coaxial depth electrode for research and diagnostic studies of neurological diseases. The requirements for this electrode include (1) strength and resistance to buckling sufficient to ensure self-forced penetration of brain tissue to a depth of 6 cm; (2) biocompatibility of the materials employed; (3) resistance to brittle fracture; and (4) a total diameter of less than 200 micrometer to minimize tissue damage. Earlier synthesis efforts using chemical vapor deposition techniques have been successful, although the process yield was 40% and an outer insulating layer had yet to be deposited. Plasma polymerization processes have been employed to realize an increase in the yield and provide an outer insulating layer. The starting material is W-26 at.% Re wire, nominally 125 micrometer in diameter. Hexamethyldisilazane(CH3)3SiNHSi(CH3)3 is used to deposit the insulating layers. The paper describes factors influencing the choice of materials, deposition techniques, and properties of electrodes.

An Investigation of Large Aircraft Handling Qualities

NASA Astrophysics Data System (ADS)

Joyce, Richard D.

An analytical technique for investigating transport aircraft handling qualities is exercised in a study using models of two such vehicles, a Boeing 747 and Lockheed C-5A. Two flight conditions are employed for climb and directional tasks, and a third included for a flare task. The analysis technique is based upon a "structural model" of the human pilot developed by Hess. The associated analysis procedure has been discussed previously in the literature, but centered almost exclusively on the characteristics of high-performance fighter aircraft. The handling qualities rating level (HQRL) and pilot induced oscillation tendencies rating level (PIORL) are predicted for nominal configurations of the aircraft and for "damaged" configurations where actuator rate limits are introduced as nonlinearites. It is demonstrated that the analysis can accommodate nonlinear pilot/vehicle behavior and do so in the context of specific flight tasks, yielding estimates of handling qualities, pilot-induced oscillation tendencies and upper limits of task performance. A brief human-in-the-loop tracking study was performed to provide a limited validation of the pilot model employed.

Use of an AC/DC/AC Electrochemical Technique to Assess the Durability of Protection Systems for Magnesium Alloys

NASA Astrophysics Data System (ADS)

Song, Sen; McCune, Robert C.; Shen, Weidian; Wang, Yar-Ming

One task under the U.S. Automotive Materials Partnership (USAMP) "Magnesium Front End Research and Development" (MFERD) Project has been the evaluation of methodologies for the assessment of protective capability for a variety of proposed protection schemes for this hypothesized multi-material, articulated structure. Techniques which consider the entire protection system, including both pretreatments and topcoats are of interest. In recent years, an adaptation of the classical electrochemical impedance spectroscopy (EIS) approach using an intermediate cathodic DC polarization step (viz. AC/DC/AC) has been employed to accelerate breakdown of coating protection, specifically at the polymer-pretreatment interface. This work reports outcomes of studies to employ the AC/DC/AC approach for comparison of protective coatings to various magnesium alloys considered for front end structures. In at least one instance, the protective coating system breakdown could be attributed to the poorer intrinsic corrosion resistance of the sheet material (AZ31) relative to die-cast AM60B.

Identification of individual foothill yellow-legged frogs (Rana boylii) using chin pattern photographs: a non-invasive and effective method for small population studies

Treesearch

K.R. Marlow; K.D. Wiseman; Clara Wheeler; J.E.  Drennan; R.E.  Jackman

2016-01-01

The ability to identify individual animals is a valuable tool in the study of amphibian population dynamics, movement ecology, social behavior, and habitat use. Numerous methods of marking amphibians have been employed including the use of passive integrated transponder (PIT) tags, radio-transmitters, elastomers, branding, and mutilation techniques such as toe...

Comparative study of hydrogen storage on metal doped mesoporous materials

NASA Astrophysics Data System (ADS)

Carraro, P. M.; Sapag, K.; Oliva, M. I.; Eimer, G. A.

2018-06-01

The hydrogen adsorption capacity of mesoporous materials MCM-41 modified with Co, Fe, Ti, Mg and Ni at 77 K and 10 bar was investigated. Various techniques including XRD, N2 adsorption and DRUV-vis were employed for the materials characterization. The results showed that a low nickel loading on MCM-41 support promoted the presence of hydrogen-favorable sites, increasing the hydrogen storage capacity.

Laboratory studies of the interaction of ions with condensed gases: Planetary applications

NASA Technical Reports Server (NTRS)

Boring, J. W.; Johnson, R. E.

1990-01-01

The work described is concerned with laboratory studies of the processes that produce the ejection of molecules from the surfaces of condensed gas solids, the change in the chemistry of the surface materials, and the relationship of these results to processes occurring in the solar system. Included is a discussion of the experimental techniques employed in making these laboratory measurements.

Does Marital Status Influence the Parenting Styles Employed by Parents?

ERIC Educational Resources Information Center

Ashiono, Benard Litali; Mwoma, Teresa B.

2015-01-01

The current study sought to establish whether parents' marital status, influence their use of specific parenting styles in Kisauni District, Kenya. A correlational research design was employed to carry out this study. Stratified sampling technique was used to select preschools while purposive sampling technique was used to select preschool…

Pedagogical Techniques Employed by the Television Show "MythBusters"

ERIC Educational Resources Information Center

Zavrel, Erik

2016-01-01

"MythBusters," the long-running though recently discontinued Discovery Channel science entertainment television program, has proven itself to be far more than just a highly rated show. While its focus is on entertainment, the show employs an array of pedagogical techniques to communicate scientific concepts to its audience. These…

How to locate & hire clinical/biomedical engineers, supervisors, managers & biomedical equipment technicians.

PubMed

Pacela, A F; Brush, L C

1993-01-01

This article has described the process and the resources available for locating and hiring clinical/biomedical engineers, supervisors, managers, and biomedical equipment technicians. First, the employer must determine the qualifications for the position, including job titles, descriptions, pay scales, and certification requirements. Next, the employer must find qualified applicants. The most common way to do this is to use "outside" contacts, such as help-wanted advertising, specialized job placement agencies, schools and colleges, military resources, regional biomedical societies, and nationwide societies. An "inside" search involves limited internal advertising of the position and using personal referrals for candidates. Finally, the employer must screen the applicants. The position description is the obvious first step in this process, but there are other pre-screening techniques, such as employment testing. Interviewing is the most common way to hire for job positions, but the interviewer needs to know about the position and ask the right questions. Post-interview screening is a final step to help determine the best job-person match.

Characterization and measurement of natural gas trace constituents. Volume 1. Arsenic. Final report, June 1989-October 1993

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

Chao, S.S.; Attari, A.

1995-01-01

The discovery of arsenic compounds, as alkylarsines, in natural gas prompted this research program to develop reliable measurement techniques needed to assess the efficiency of removal processes for these environmentally sensitive substances. These techniques include sampling, speciation, quantitation and on-line instrumental methods for monitoring the total arsenic concentration. The current program has yielded many products, including calibration standards, arsenic-specific sorbents, sensitive analytical methods and instrumentation. Four laboratory analytical methods have been developed and successfully employed for arsenic determination in natural gas. These methods use GC-AED and GC-MS instruments to speciate alkylarsines, and peroxydisulfate extraction with FIAS, special carbon sorbent withmore » XRF and an IGT developed sorbent with GFAA for total arsenic measurement.« less

An investigation of combustion and entropy noise

NASA Technical Reports Server (NTRS)

Strahle, W. C.

1977-01-01

The relative importance of entropy and direct combustion noise in turbopropulsion systems and the parameters upon which these noise sources depend were studied. Theory and experiment were employed to determine that at least with the apparatus used here, entropy noise can dominate combustion noise if there is a sufficient pressure gradient terminating the combustor. Measurements included combustor interior fluctuating pressure, near and far field fluctuating pressure, and combustor exit plane fluctuating temperatures, as well as mean pressures and temperatures. Analysis techniques included spectral, cross-correlation, cross power spectra, and ordinary and partial coherence analysis. Also conducted were combustor liner modification experiments to investigate the origin of the frequency content of combustion noise. Techniques were developed to extract nonpropagational pseudo-sound and the heat release fluctuation spectra from the data.

Ion beam and plasma methods of producing diamondlike carbon films

NASA Technical Reports Server (NTRS)

Swec, Diane M.; Mirtich, Michael J.; Banks, Bruce A.

1988-01-01

A variety of plasma and ion beam techniques was employed to generate diamondlike carbon films. These methods included the use of RF sputtering, dc glow discharge, vacuum arc, plasma gun, ion beam sputtering, and both single and dual ion beam deposition. Since films were generated using a wide variety of techniques, the physico-chemical properties of these films varied considerably. In general, these films had characteristics that were desirable in a number of applications. For example, the films generated using both single and dual ion beam systems were evaluated for applications including power electronics as insulated gates and protective coatings on transmitting windows. These films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Nuclear reaction and combustion analysis indicated hydrogen to carbon ratios to be 1.00, which allowed the films to have good transmittance not only in the infrared, but also in the visible. Other evaluated properties of these films include band gap, resistivity, adherence, density, microhardness, and intrinsic stress. The results of these studies and those of the other techniques for depositing diamondlike carbon films are presented.

Videometric Applications in Wind Tunnels

NASA Technical Reports Server (NTRS)

Burner, A. W.; Radeztsky, R. H.; Liu, Tian-Shu

1997-01-01

Videometric measurements in wind tunnels can be very challenging due to the limited optical access, model dynamics, optical path variability during testing, large range of temperature and pressure, hostile environment, and the requirements for high productivity and large amounts of data on a daily basis. Other complications for wind tunnel testing include the model support mechanism and stringent surface finish requirements for the models in order to maintain aerodynamic fidelity. For these reasons nontraditional photogrammetric techniques and procedures sometimes must be employed. In this paper several such applications are discussed for wind tunnels which include test conditions with Mach number from low speed to hypersonic, pressures from less than an atmosphere to nearly seven atmospheres, and temperatures from cryogenic to above room temperature. Several of the wind tunnel facilities are continuous flow while one is a short duration blowdown facility. Videometric techniques and calibration procedures developed to measure angle of attack, the change in wing twist and bending induced by aerodynamic load, and the effects of varying model injection rates are described. Some advantages and disadvantages of these techniques are given and comparisons are made with non-optical and more traditional video photogrammetric techniques.

New techniques for laser beam atmospheric extinction measurements from manned and unmanned aerospace vehicles

NASA Astrophysics Data System (ADS)

Sabatini, Roberto; Richardson, Mark

2013-03-01

Novel techniques for laser beam atmospheric extinction measurements, suitable for several air and space platform applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ= 1064 nm and λ= 1550 nm. This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

Novel atmospheric extinction measurement techniques for aerospace laser system applications

NASA Astrophysics Data System (ADS)

Sabatini, Roberto; Richardson, Mark

2013-01-01

Novel techniques for laser beam atmospheric extinction measurements, suitable for manned and unmanned aerospace vehicle applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 kHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

Layer-by-Layer Enabled Nanomaterials for Chemical Sensing and Energy Conversion

NASA Astrophysics Data System (ADS)

Paterno, Leonardo G.; Soler, Maria A. G.

2013-06-01

The layer-by-layer (LbL) technique is a wet chemical method for the assembly of ultrathin films, with thicknesses up to 100 nm. This method is based on the successive transfer of molecular layers to a solid substrate that is dipped into cationic and anionic solutions in an alternating fashion. The adsorption is mainly driven by electrostatic interactions so that many molecular and nanomaterial systems can be engineered under this method. Moreover, it is inexpensive, can be easily performed, and does not demand sophisticated equipment or clean rooms. The most explored use of the LbL technique is to build up molecular devices for chemical sensing and energy conversion. Both applications require ultrathin films where specific elements must be organized with high control of thickness and spatial distribution, preferably in the nanolength and mesolength scales. In chemical sensors, the LbL technique is employed to assemble specific sensoactive materials such as conjugated polymers, enzymes, and immunological elements onto appropriated electrodes. Molecular recognition events are thus transduced by the assembled sensoactive layer. In energy-conversion devices, the LbL technique can be employed to fabricate different device's parts including electrodes, active layers, and auxiliary layers. In both applications, the devices' performance can be fully modulated and improved by simply varying film thickness and molecular architecture. The present review article highlights the main features of the LbL technique and provides a brief description of different (bio)chemical sensors, solar cells, and organic light-emitting diodes enabled by the LbL approach.

Airway emergencies presenting to the paediatric emergency department requiring advanced management techniques.

PubMed

Simma, Leopold; Cincotta, Domenic; Sabato, Stefan; Long, Elliot

2017-09-01

Airway emergencies presenting to the emergency department (ED) are usually managed with conventional equipment and techniques. The patient group managed urgently in the operating room (OR) has not been described. This study aims to describe a case series of children presenting to the ED with airway emergencies managed urgently in the OR, particularly the anaesthetic equipment and techniques used and airway findings. A retrospective cohort study undertaken at The Royal Children's Hospital, Melbourne, Australia. All patients presenting to the ED between 1 January 2012 and 30 July 2015 (42 months) with an airway emergency who were subsequently managed in the OR were included. Patient characteristics, anaesthetic equipment and technique and airway findings were recorded. Twenty-two airway emergencies in 21 patients were included over the study period, on average one every 2 months. Median age was 18 months and 43% were male. Inhalational induction was used in 77.3%, combined inhalational and intravenous induction in 9.1%, and intravenous induction alone in 13.6%. The most commonly used inhalational induction agent was sevoflurane, and the most commonly used intravenous induction agents were ketamine and propofol. Ten airway emergencies did not require intubation, seven for removal of inhaled foreign body, two with progressive tracheal stenosis requiring emergent dilatation and one examination under anaesthesia to rule out inhaled foreign body. Of the 12 airway emergencies that required immediate intubation, direct laryngoscopy was used in 9 and fibre-optic intubating bronchoscopy in 3. For intubations performed by direct laryngoscopy, one was difficult (Cormack and Lehane grade 3). First pass success was 83.3%. Adverse events occurred in 3/22 (13.6%) cases. Advanced airway techniques, including inhalational induction and intubation via fibre-optic intubating bronchoscope, are rarely but predictably required in the management of patients presenting to the ED. Institutions caring for children should prepare in advance where such patients should be managed, by whom, and provide equipment and training for their care. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Dosimetry and field matching for radiotherapy to the breast and superclavicular fossa

NASA Astrophysics Data System (ADS)

Winfield, Elizabeth

Radiotherapy for early breast cancer aims to achieve local disease control and decrease loco-regional recurrence rates. Treatment may be directed to breast or chest wall alone or, include regional lymph nodes. When using tangential fields to treat the breast a separate anterior field directed to the axilla and supraclavicular fossa (SCF) is needed to treat nodal areas. The complex geometry of this region necessitates matching of adjacent radiation fields in three dimensions. The potential exists for zones of overdosage or underdosage along the match line. Cosmetic results may be compromised if treatment fields are not accurately aligned. Techniques for field matching vary between centres in the UK. A study of dosimetry across the match line region using different techniques, as reported in the multi-centre START Trial Quality Assurance (QA) programme, was undertaken. A custom-made anthropomorphic phantom was designed to assess dose distribution in three dimensions using film dosimetry. Methods with varying degrees of complexity were employed to match tangential and SCF beams. Various techniques combined half beam blocking and machine rotations to achieve geometric alignment. Matching of asymmetric beams allowed a single isocentre technique to be used. Where field matching was not undertaken a gap between tangential and SCF fields was employed. Results demonstrated differences between techniques in addition to variations within the same technique between different centres. Geometric alignment techniques produced more homogenous dose distributions in the match region than gap techniques or those techniques not correcting for field divergence. For this multi-centre assessment of match plane techniques film dosimetry used in conjunction with a breast shaped phantom provided relative dose information. This study has highlighted the difficulties of matching treatment fields to achieve homogenous dose distribution through the region of the match plane and the degree of inhomogeneity as a consequence of a gap between treatment fields.

Wireless sensor and data transmission needs and technologies for patient monitoring in the operating room and intensive care unit.

PubMed

Paksuniemi, M; Sorvoja, H; Alasaarela, E; Myllyla, R

2005-01-01

In the intensive care unit, or during anesthesia, patients are attached to monitors by cables. These cables obstruct nursing staff and hinder the patients from moving freely in the hospital. However, rapidly developing wireless technologies are expected to solve these problems. To this end, this study revealed problem areas in current patient monitoring and established the most important medical parameters to monitor. In addition, usable wireless techniques for short-range data transmission were explored and currently employed wireless applications in the hospital environment were studied. The most important parameters measured of the patient include blood pressures, electrocardiography, respiration rate, heart rate and temperature. Currently used wireless techniques in hospitals are based on the WMTS and WLAN standards. There are no viable solutions for short-range data transmission from patient sensors to patient monitors, but potentially usable techniques in the future are based on the WPAN standards. These techniques include Bluetooth, ZigBee and UWB. Other suitable techniques might be based on capacitive or inductive coupling. The establishing of wireless techniques depends on ensuring the reliability of data transmission, eliminating disturbance by other wireless devices, ensuring patient data security and patient safety, and lowering the power consumption and price.

Internal amplification controls have not been employed in fungal PCR hence potential false negative results.

PubMed

Paterson, R R M

2007-01-01

Polymerase chain reaction (PCR) is subject to false negative results. Samples of fungi with the genes of interest (e.g. a disease or mycotoxin) may be categorized as negative and safe as a consequence. Fungi are eukaryotic organisms that are involved in many fields of human activity such as antibiotic, toxin and food production. Certain taxa are implicated in human, animal and plant diseases. However, fungi are difficult to identify and PCR techniques have been proposed increasingly for this purpose. Internal amplification controls (IACs) will ameliorate the situation and need to become mandatory. These are nucleic acids that posses a sequence which will provide a PCR product (i) using the same primers employed for the target gene, and (ii) that will not coincide on the gel with the product of the target gene. Only one group of workers employed an IAC, to respond to potential inhibition, which was reported in 1995 from this present assessment of numerous reports. Inhibitors in cultures need to be minimized, and secondary metabolites are an obvious source. The fields reviewed herein include medical mycology, mycotoxicology, environmental mycology and plant mycology. The conclusion is that previous reports are compromised because IACs have not been employed in fungal PCR; future research must include this control at an early stage.

Enzyme assisted extraction of biomolecules as an approach to novel extraction technology: A review.

PubMed

Nadar, Shamraja S; Rao, Priyanka; Rathod, Virendra K

2018-06-01

An interest in the development of extraction techniques of biomolecules from various natural sources has increased in recent years due to their potential applications particularly for food and nutraceutical purposes. The presence of polysaccharides such as hemicelluloses, starch, pectin inside the cell wall, reduces the extraction efficiency of conventional extraction techniques. Conventional techniques also suffer from low extraction yields, time inefficiency and inferior extract quality due to traces of organic solvents present in them. Hence, there is a need of the green and novel extraction methods to recover biomolecules. The present review provides a holistic insight to various aspects related to enzyme aided extraction. Applications of enzymes in the recovery of various biomolecules such as polyphenols, oils, polysaccharides, flavours and colorants have been highlighted. Additionally, the employment of hyphenated extraction technologies can overcome some of the major drawbacks of enzyme based extraction such as longer extraction time and immoderate use of solvents. This review also includes hyphenated intensification techniques by coupling conventional methods with ultrasound, microwave, high pressure and supercritical carbon dioxide. The last section gives an insight on application of enzyme immobilization as a strategy for large scale extraction. Immobilization of enzymes on magnetic nanoparticles can be employed to enhance the operational performance of the system by multiple use of expensive enzymes making them industrially and economically feasible. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development and application of computational aerothermodynamics flowfield computer codes

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj

1993-01-01

Computations are presented for one-dimensional, strong shock waves that are typical of those that form in front of a reentering spacecraft. The fluid mechanics and thermochemistry are modeled using two different approaches. The first employs traditional continuum techniques in solving the Navier-Stokes equations. The second-approach employs a particle simulation technique (the direct simulation Monte Carlo method, DSMC). The thermochemical models employed in these two techniques are quite different. The present investigation presents an evaluation of thermochemical models for nitrogen under hypersonic flow conditions. Four separate cases are considered. The cases are governed, respectively, by the following: vibrational relaxation; weak dissociation; strong dissociation; and weak ionization. In near-continuum, hypersonic flow, the nonequilibrium thermochemical models employed in continuum and particle simulations produce nearly identical solutions. Further, the two approaches are evaluated successfully against available experimental data for weakly and strongly dissociating flows.

40 CFR 426.135 - Standards of performance for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... greater than 50 gallons per day of process waste water, and employs hydrofluoric acid finishing techniques... any 1 day Average of daily values for 30 consecutive days shall not exceed— Lead 0.2 0.1 Fluoride 26.0... waste water, and employs hydrofluoric acid finishing techniques shall meet the following limitations...

40 CFR 426.135 - Standards of performance for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... greater than 50 gallons per day of process waste water, and employs hydrofluoric acid finishing techniques... any 1 day Average of daily values for 30 consecutive days shall not exceed— Lead 0.2 0.1 Fluoride 26.0... waste water, and employs hydrofluoric acid finishing techniques shall meet the following limitations...

40 CFR 426.135 - Standards of performance for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... greater than 50 gallons per day of process waste water, and employs hydrofluoric acid finishing techniques... any 1 day Average of daily values for 30 consecutive days shall not exceed— Lead 0.2 0.1 Fluoride 26.0... waste water, and employs hydrofluoric acid finishing techniques shall meet the following limitations...

Managing Age Discrimination: An Examination of the Techniques Used when Seeking Employment

ERIC Educational Resources Information Center

Berger, Ellie D.

2009-01-01

Purpose: This article examines the age-related management techniques used by older workers in their search for employment. Design and Methods: Data are drawn from interviews with individuals aged 45-65 years (N = 30). Results: Findings indicate that participants develop "counteractions" and "concealments" to manage perceived age discrimination.…

AMTV headway sensor and safety design

NASA Technical Reports Server (NTRS)

Johnston, A. R.; Nelson, M.; Cassell, P.; Herridge, J. T.

1980-01-01

A headway sensing system for an automated mixed traffic vehicle (AMTV) employing an array of optical proximity sensor elements is described, and its performance is presented in terms of object detection profiles. The problem of sensing in turns is explored experimentally and requirements for future turn sensors are discussed. A recommended headway sensor configuration, employing multiple source elements in the focal plane of one lens operating together with a similar detector unit, is described. Alternative concepts including laser radar, ultrasonic sensing, imaging techniques, and radar are compared to the present proximity sensor approach. Design concepts for an AMTV body which will minimize the probability of injury to pedestrians or passengers in the event of a collision are presented.

Description of the GMAO OSSE for Weather Analysis Software Package: Version 3

NASA Technical Reports Server (NTRS)

Koster, Randal D. (Editor); Errico, Ronald M.; Prive, Nikki C.; Carvalho, David; Sienkiewicz, Meta; El Akkraoui, Amal; Guo, Jing; Todling, Ricardo; McCarty, Will; Putman, William M.;

The contemporary role of 1 vs. 2-stage repair for proximal hypospadias.

PubMed

Dason, Shawn; Wong, Nathan; Braga, Luis H

2014-12-01

This review discusses the most commonly employed techniques in the repair of proximal hypospadias, highlighting the advantages and disadvantages of single versus staged surgical techniques. Hypospadias can have a spectrum of severity with a urethral meatus ranging from the perineum to the glans. Associated abnormalities are commonly found with proximal hypospadias and encompass a large spectrum, including ventral curvature (VC) up to 50 degrees or more, ventral skin deficiency, a flattened glans, penile torsion and penoscrotal transposition. Our contemporary understanding of hypospadiology is comprised of a foundation built by experts who have described a number of techniques and their outcomes, combined with survey data detailing practice patterns. The two largest components of hypospadias repair include repair of VC and urethroplasty. VC greater than 20 degrees is considered clinically relevant to warrant surgical correction. To repair VC, the penis is first degloved-a procedure that may reduce or remove curvature by itself in some cases. Residual curvature is then repaired with dorsal plication techniques, transection of the urethral plate, and/or ventral lengthening techniques. Urethroplasty takes the form of 1- or 2-stage repairs. One-stage options include the tubularized incised urethroplasty (TIP) or various graft or flap-based techniques. Two-stage options also include grafts or flaps, including oral mucosal and preputial skin grafting. One stage repairs are an attractive option in that they may reduce cost, hospital stay, anesthetic risks, and time to the final result. The downside is that these repairs require mastery of multiple techniques may be more complex, and-depending on technique-have higher complication rates. Two-stage repairs are preferred by the majority of surveyed hypospadiologists. The 2-stage repair is versatile and has satisfactory outcomes, but necessitates a second procedure. Given the lack of clear high-quality evidence supporting the superiority of one approach over the others, hypospadiologists should develop their own algorithm, which gives them the best outcomes.

Finite Element Modeling, Simulation, Tools, and Capabilities at Superform

NASA Astrophysics Data System (ADS)

Raman, Hari; Barnes, A. J.

2010-06-01

Over the past thirty years Superform has been a pioneer in the SPF arena, having developed a keen understanding of the process and a range of unique forming techniques to meet varying market needs. Superform’s high-profile list of customers includes Boeing, Airbus, Aston Martin, Ford, and Rolls Royce. One of the more recent additions to Superform’s technical know-how is finite element modeling and simulation. Finite element modeling is a powerful numerical technique which when applied to SPF provides a host of benefits including accurate prediction of strain levels in a part, presence of wrinkles and predicting pressure cycles optimized for time and part thickness. This paper outlines a brief history of finite element modeling applied to SPF and then reviews some of the modeling tools and techniques that Superform have applied and continue to do so to successfully superplastically form complex-shaped parts. The advantages of employing modeling at the design stage are discussed and illustrated with real-world examples.

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

Ingold, G., E-mail: gerhard.ingold@psi.ch; Rittmann, J., E-mail: jochen.rittmann@psi.ch; Beaud, P.

The ESB instrument at the SwissFEL ARAMIS hard X-ray free electron laser is designed to perform pump-probe experiments in condensed matter and material science employing photon-in and photon-out techniques. It includes a femtosecond optical laser system to generate a variety of pump beams, a X-ray optical scheme to tailor the X-ray probe beam, shot-to-shot diagnostics to monitor the X-ray intensity and arrival time, and two endstations operated at a single focus position that include multi-purpose sample environments and 2D pixel detectors for data collection.

A study of unmanned mission opportunities to comets and asteroids

NASA Technical Reports Server (NTRS)

Mann, F. I.; Horsewood, J. L.; Bjorkman, W.

1974-01-01

Several unmanned multiple-target mission opportunities to comets and asteroids were studied. The targets investigated include Grigg-Skjellerup, Giacobini-Zinner, Tuttle-Giacobini-Kresak, Borrelly, Halley, Schaumasse, Geographos, Eros, Icarus, and Toro, and the trajectories consist of purely ballistic flight, except that powered swingbys and deep space burns are employed when necessary. Optimum solar electric rendezvous trajectories to the comets Giacobini-Zinner/85, Borrelly/87, and Temple (2)/83 and /88 employing the 8.67 kw Sert III spacecraft modified for interplanetary flight were also investigated. The problem of optimizing electric propulsion heliocentric trajectories, including the effects of geocentric launch asymptote declination on launch vehicle performance capability, was formulated, and a solution developed using variational calculus techniques. Improvements were made to the HILTOP trajectory optimization computer program. An error analysis of high-thrust maneuvers involving spin-stabilized spacecraft was developed and applied to a synchronous meteorological satellite mission.

Brachytherapy devices and methods employing americium-241

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

Gray, L. A.

1985-04-16

Sources and methods for radiation therapy, particularly brachytherapy, employing americium-241 (60 keV gamma emission and 433 year half-life) provide major advantages for radiotherapy, including simplified radiation protection, dose reduction to healthy tissue, increased dose to tumor, and improved dose distributions. A number of apparent drawbacks and unfavorable considerations including low gamma factor, high self-absorption, increased activity required and alpha-particle generation leading to helium gas pressure buildup and potential neutron contamination in the generated radiation are all effectively dealt with and overcome through recognition of subtle favorable factors unique to americium-241 among brachytherapy sources and through suitable constructional techniques. Due tomore » an additional amount of radiation, in the order of 50%, provided primarily to nearby regions as a result of Compton scatter in tissue and water, higher dose rates occur than would be predicted by conventional calculations.« less

Dietary Assessment on a Mobile Phone Using Image Processing and Pattern Recognition Techniques: Algorithm Design and System Prototyping.

PubMed

Probst, Yasmine; Nguyen, Duc Thanh; Tran, Minh Khoi; Li, Wanqing

2015-07-27

Dietary assessment, while traditionally based on pen-and-paper, is rapidly moving towards automatic approaches. This study describes an Australian automatic food record method and its prototype for dietary assessment via the use of a mobile phone and techniques of image processing and pattern recognition. Common visual features including scale invariant feature transformation (SIFT), local binary patterns (LBP), and colour are used for describing food images. The popular bag-of-words (BoW) model is employed for recognizing the images taken by a mobile phone for dietary assessment. Technical details are provided together with discussions on the issues and future work.

Pseudo-random tool paths for CNC sub-aperture polishing and other applications.

PubMed

Dunn, Christina R; Walker, David D

2008-11-10

In this paper we first contrast classical and CNC polishing techniques in regard to the repetitiveness of the machine motions. We then present a pseudo-random tool path for use with CNC sub-aperture polishing techniques and report polishing results from equivalent random and raster tool-paths. The random tool-path used - the unicursal random tool-path - employs a random seed to generate a pattern which never crosses itself. Because of this property, this tool-path is directly compatible with dwell time maps for corrective polishing. The tool-path can be used to polish any continuous area of any boundary shape, including surfaces with interior perforations.

Taenia asiatica: the Most Neglected Human Taenia and the Possibility of Cysticercosis

PubMed Central

2013-01-01

Not only Taenia solium and Taenia saginata, but also Taenia asiatica infects humans. The last species is not included in the evaluation of the specificity of the immunodiagnostic techniques for taeniasis/cysticercosis. There is currently no specific immunodiagnostic method for T. asiatica available. Therefore, due to the fact that molecular techniques (the only tool to distinguish the 3 Taenia species) are normally not employed in routine diagnostic methods, the 2 questions concerning T. asiatica (its definite geographic distribution and its ability to cause human cysticercosis), remain open, turning T. asiatica into the most neglected agent of human taeniasis-cysticercosis. PMID:23467406

Large scale GW calculations

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

Govoni, Marco; Galli, Giulia

We present GW calculations of molecules, ordered and disordered solids and interfaces, which employ an efficient contour deformation technique for frequency integration and do not require the explicit evaluation of virtual electronic states nor the inversion of dielectric matrices. We also present a parallel implementation of the algorithm, which takes advantage of separable expressions of both the single particle Green’s function and the screened Coulomb interaction. The method can be used starting from density functional theory calculations performed with semilocal or hybrid functionals. The newly developed technique was applied to GW calculations of systems of unprecedented size, including water/semiconductor interfacesmore » with thousands of electrons.« less

Large Scale GW Calculations

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

Govoni, Marco; Galli, Giulia

We present GW calculations of molecules, ordered and disordered solids and interfaces, which employ an efficient contour deformation technique for frequency integration and do not require the explicit evaluation of virtual electronic states nor the inversion of dielectric matrices. We also present a parallel implementation of the algorithm which takes advantage of separable expressions of both the single particle Green's function and the screened Coulomb interaction. The method can be used starting from density functional theory calculations performed with semilocal or hybrid functionals. We applied the newly developed technique to GW calculations of systems of unprecedented size, including water/semiconductor interfacesmore » with thousands of electrons.« less

Investigation of light scattering as a technique for detecting discrete soot particles in a luminous flame

NASA Technical Reports Server (NTRS)

1978-01-01

The practicability of using a classical light-scattering technique, involving comparison of angular scattering intensity patterns with theoretically determined Mie and Rayleight patterns, to detect discrete soot particles (diameter less than 50 nm) in premixed propane/air and propane/oxygen-helium flames is considered. The experimental apparatus employed in this investigation included a laser light source, a flat-flame burner, specially coated optics, a cooled photomultiplier detector, and a lock-in voltmeter readout. Although large, agglomerated soot particles were detected and sized, it was not possible to detect small, discrete particles. The limiting factor appears to be background scattering by the system's optics.

Multidetector Computer Tomography: Evaluation of Blunt Chest Trauma in Adults

PubMed Central

Matos, António P.; Mascarenhas, Vasco; Herédia, Vasco

2014-01-01

Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall. PMID:25295188

Multidetector computer tomography: evaluation of blunt chest trauma in adults.

PubMed

Palas, João; Matos, António P; Mascarenhas, Vasco; Herédia, Vasco; Ramalho, Miguel

2014-01-01

Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall.

Large scale GW calculations

DOE PAGES

Govoni, Marco; Galli, Giulia

2015-01-12

We present GW calculations of molecules, ordered and disordered solids and interfaces, which employ an efficient contour deformation technique for frequency integration and do not require the explicit evaluation of virtual electronic states nor the inversion of dielectric matrices. We also present a parallel implementation of the algorithm, which takes advantage of separable expressions of both the single particle Green’s function and the screened Coulomb interaction. The method can be used starting from density functional theory calculations performed with semilocal or hybrid functionals. The newly developed technique was applied to GW calculations of systems of unprecedented size, including water/semiconductor interfacesmore » with thousands of electrons.« less

Anomalous Systemic Artery to the Left Lower Lobe: Literature Review and a New Surgical Technique.

PubMed

Miller, Jacob R; Lancaster, Timothy S; Abarbanell, Aaron M; Manning, Peter B; Eghtesady, Pirooz

2018-05-01

Anomalous systemic arterial supply to the basal segments of the left lower lobe without coexisting pulmonary artery connection is a rare anomaly. Most feel treatment is necessary; however, the ideal strategy is unclear. Treatments described include embolization, pulmonary resection, or anastomosis to the native pulmonary artery. We recently encountered an infant with this anomaly and present a literature review summarizing all recent reports. Additionally, we describe a novel surgical technique to create a tension-free anastomosis utilizing segmental aortic translocation that we employed in our patient due to a large distance between the anomalous vessel and native left pulmonary artery.

New mechanistic insights in the NH 3-SCR reactions at low temperature

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

Ruggeri, Maria Pia; Selleri, Tomasso; Nova, Isabella

2016-05-06

The present study is focused on the investigation of the low temperature Standard SCR reaction mechanism over Fe- and Cu-promoted zeolites. Different techniques are employed, including in situ DRIFTS, transient reaction analysis and chemical trapping techniques. The results present strong evidence of nitrite formation in the oxidative activation of NO and of their role in SCR reactions. These elements lead to a deeper understanding of the standard SCR chemistry at low temperature and can potentially improve the consistency of mechanistic mathematical models. Furthermore, comprehension of the mechanism on a fundamental level can contribute to the development of improved SCR catalysts.

Resisting the "Employability" Doctrine through Anarchist Pedagogies & Prefiguration

ERIC Educational Resources Information Center

Osborne, Natalie; Grant-Smith, Deanna

2017-01-01

Increasingly those working in higher education are tasked with targeting their teaching approaches and techniques to improve the "employability" of graduates. However, this approach is promoted with little recognition that enhanced employability does not guarantee employment outcomes or the tensions inherent in pursuing this agenda. The…

Root causes investigation of catastrophic optical bulk damage in high-power InGaAs-AlGaAs strained QW lasers

NASA Astrophysics Data System (ADS)

Sin, Yongkun; Lingley, Zachary; Ayvazian, Talin; Brodie, Miles; Ives, Neil

2018-02-01

High-power single-mode (SM) and multi-mode (MM) InGaAs-AlGaAs strained quantum well (QW) lasers are critical components for both terrestrial and space satellite communications systems. Since these lasers predominantly fail by catastrophic and sudden degradation due to COD, it is especially crucial for space satellite applications to investigate reliability, failure modes, and degradation mechanisms of these lasers. Our group reported a new failure mode in MM and SM InGaAs-AlGaAs strained QW lasers in 2009 and 2016, respectively. Our group also reported in 2017 that bulk failure due to catastrophic optical bulk damage (COBD) is the dominant failure mode of both SM and MM lasers that were subject to long-term life-tests. For the present study, we report root causes investigation of COBD by performing long-term lifetests followed by failure mode analysis (FMA) using various micro-analytical techniques including electron beam induced current (EBIC), time-resolved electroluminescence (EL), focused ion beam (FIB), high-resolution transmission electron microscopy (TEM), and deep level transient spectroscopy (DLTS). Our life-tests with accumulated test hours of over 25,000 hours for SM lasers and over 35,000 hours for MM lasers generated a number of COBD failures with various failure times. EBIC techniques were employed to study dark line defects (DLDs) generated in SM COBD failures stressed under different test conditions. FIB and high-resolution TEM were employed to prepare cross sectional and plan view TEM specimens to study DLD areas (dislocations) in post-aged SM lasers. Time-resolved EL techniques were employed to study initiation and progressions of dark spots and dark lines in real time as MM lasers were aged. Lastly, to investigate precursor signatures of failure and degradation mechanisms responsible for COBD in both SM and MM lasers, we employed DLTS techniques to study a role that electron traps (non-radiative recombination centers) play in degradation of these lasers. Our in-depth root causes investigation results are reported.

The Role of Co-Oxidation and Commensalism in the Biodegradation of Recalcitrant Molecules.

DTIC Science & Technology

1980-01-08

readily utilized by microorganisms. A species of Nocardia that can utilize hydrocarbon substrates does cooxidize terpenes to menthol and several other...on a wide array of hydrocarbons including crude oil will cooxidize p-menthane to menthol and other products. At the present the intermediates, other...than menthol , resulting from these cooxidations are being analyzed. After determining structures we will employ enrichment culture techniques to

[The application of radiological image in forensic medicine].

PubMed

Zhang, Ji-Zong; Che, Hong-Min; Xu, Li-Xiang

2006-04-01

Personal identification is an important work in forensic investigation included sex discrimination, age and stature estimation. Human identification depended on radiological image technique analysis is a practice and proper method in forensic science field. This paper intended to understand the advantage and defect by reviewed the employing of forensic radiology in forensic science field broadly and provide a reference to perfect the application of forensic radiology in forensic science field.

Learning experience in endodontics: Brazilian students' perceptions.

PubMed

Seijo, Marilia O S; Ferreira, Efigênia F; Ribeiro Sobrinho, Antônio P; Paiva, Saul M; Martins, Renata C

2013-05-01

Including students' perceptions in the educational process is considered a key component in monitoring the quality of academic programs. This study aimed to evaluate the concept of one's learning experience in endodontic teaching from the perspective of a group of Brazilian students. A total of 126 self-administered, structured questionnaires were distributed to undergraduate dental students enrolled in endodontics courses during the second semester of the 2009 academic year. The questionnaires were administered during final examinations and focused on students' opinions concerning learning during endodontic treatments, time spent during endodontic treatments, difficulties found during endodontic treatments, quality of endodontic treatments performed, characteristics of the technique employed, and suggestions to improve endodontic teaching. Ninety-one percent of the questionnaires were returned for evaluation. The obtained answers were discussed and analyzed, thereby generating quantitative and qualitative data showing students' perceptions of their experiences in endodontics courses. The main points that can affect the teaching of endodontics, according to the undergraduate students, included patients' absences and delays, selection of patients, preclinical and clinical training, difficulties found, type of technique employed, and teachers' orientation during endodontic treatment. The students' perceptions provided valuable information about the development of the course and the teacher-student relationship, together with the added intention of enhancing the teaching of endodontics as well as other courses.

A blessing and a curse? Political institutions in the growth and decay of generalized trust: a cross-national panel analysis, 1980-2009.

PubMed

Robbins, Blaine G

2012-01-01

Despite decades of research on social capital, studies that explore the relationship between political institutions and generalized trust-a key element of social capital-across time are sparse. To address this issue, we use various cross-national public-opinion data sets including the World Values Survey and employ pooled time-series OLS regression and fixed- and random-effects estimation techniques on an unbalanced panel of 74 countries and 248 observations spread over a 29-year time period. With these data and methods, we investigate the impact of five political-institutional factors-legal property rights, market regulations, labor market regulations, universality of socioeconomic provisions, and power-sharing capacity-on generalized trust. We find that generalized trust increases monotonically with the quality of property rights institutions, that labor market regulations increase generalized trust, and that power-sharing capacity of the state decreases generalized trust. While generalized trust increases as the government regulation of credit, business, and economic markets decreases and as the universality of socioeconomic provisions increases, both effects appear to be more sensitive to the countries included and the modeling techniques employed than the other political-institutional factors. In short, we find that political institutions simultaneously promote and undermine generalized trust.

A Blessing and a Curse? Political Institutions in the Growth and Decay of Generalized Trust: A Cross-National Panel Analysis, 1980–2009

PubMed Central

Robbins, Blaine G.

2012-01-01

Despite decades of research on social capital, studies that explore the relationship between political institutions and generalized trust–a key element of social capital–across time are sparse. To address this issue, we use various cross-national public-opinion data sets including the World Values Survey and employ pooled time-series OLS regression and fixed- and random-effects estimation techniques on an unbalanced panel of 74 countries and 248 observations spread over a 29-year time period. With these data and methods, we investigate the impact of five political-institutional factors–legal property rights, market regulations, labor market regulations, universality of socioeconomic provisions, and power-sharing capacity–on generalized trust. We find that generalized trust increases monotonically with the quality of property rights institutions, that labor market regulations increase generalized trust, and that power-sharing capacity of the state decreases generalized trust. While generalized trust increases as the government regulation of credit, business, and economic markets decreases and as the universality of socioeconomic provisions increases, both effects appear to be more sensitive to the countries included and the modeling techniques employed than the other political-institutional factors. In short, we find that political institutions simultaneously promote and undermine generalized trust. PMID:22558122

Estimation of single plane unbalance parameters of a rotor-bearing system using Kalman filtering based force estimation technique

NASA Astrophysics Data System (ADS)

Shrivastava, Akash; Mohanty, A. R.

2018-03-01

This paper proposes a model-based method to estimate single plane unbalance parameters (amplitude and phase angle) in a rotor using Kalman filter and recursive least square based input force estimation technique. Kalman filter based input force estimation technique requires state-space model and response measurements. A modified system equivalent reduction expansion process (SEREP) technique is employed to obtain a reduced-order model of the rotor system so that limited response measurements can be used. The method is demonstrated using numerical simulations on a rotor-disk-bearing system. Results are presented for different measurement sets including displacement, velocity, and rotational response. Effects of measurement noise level, filter parameters (process noise covariance and forgetting factor), and modeling error are also presented and it is observed that the unbalance parameter estimation is robust with respect to measurement noise.

[Comparative trial between traditional cesarean section and Misgav-Ladach technique].

PubMed

Gutiérrez, José Gabriel Tamayo; Coló, José Antonio Sereno; Arreola, María Sandra Huape

2008-02-01

The cesarean section was designed to extract to the neoborn, when the childbirth becomes difficult by the natural routes. The institutional obstetrical work demands long surgical time and high raw materials; therefore, simpler procedures must be implemented. To compare traditional cesarean section vs Misgav-Ladach technique to assess surgical time, and hospital stay and costs. Forty-eight pregnant patients at term with obstetrical indication for cesarean delivery were randomized in two groups: 24 were submitted to traditional cesarean and 24 to Misgav-Ladach technique. The outcomes included surgical time, bleeding, amount of sutures employed, pain intensity and some others adverse effects. The surgical time with Misgav-Ladach technique was shorter compared with traditional cesarean section, bleeding was consistently lesser and pain was also low. None adverse effects were registered in both groups. Although short follow-up showed significant operative time reduction and less bleeding, longer follow-up should be desirable in order to confirm no abdominal adhesions.

Fiber Optic Thermal Health Monitoring of Aerospace Structures and Materials

NASA Technical Reports Server (NTRS)

Wu, Meng-Chou; Winfree, William P.; Allison, Sidney G.

2009-01-01

A new technique is presented for thermographic detection of flaws in materials and structures by performing temperature measurements with fiber Bragg gratings. Individual optical fibers with multiple Bragg gratings employed as surface temperature sensors were bonded to the surfaces of structures with subsurface defects or thickness variations. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The investigated structures included a 10-ply composite specimen with subsurface delaminations of various sizes and depths. The data obtained from grating sensors were further analyzed with thermal modeling to reveal particular characteristics of the interested areas. These results were found to be consistent with those from conventional thermography techniques. Limitations of the technique were investigated using both experimental and numerical simulation techniques. Methods for performing in-situ structural health monitoring are discussed.

Giga-ohm seals on intracellular membranes: a technique for studying intracellular ion channels in intact cells.

PubMed

Jonas, E A; Knox, R J; Kaczmarek, L K

1997-07-01

A method is outlined for obtaining giga-ohm seals on intracellular membranes in intact cells. The technique employs a variant of the patch-clamp technique: a concentric electrode arrangement protects an inner patch pipette during penetration of the plasma membrane, after which a seal can be formed on an internal organelle membrane. Using this technique, successful recordings can be obtained with the same frequency as with conventional patch clamping. To localize the position of the pipette within cells, lipophilic fluorescent dyes are included in the pipette solution. These dyes stain the membrane of internal organelles during seal formation and can then be visualized by video-enhanced or confocal imaging. The method can detect channels activated by inositol trisphosphate, as well as other types of intracellular membrane ion channel activity, and should facilitate studies of internal membranes in intact neurons and other cell types.

Knik Glacier, Alaska; summary of 1979, 1980, and 1981 data and introduction of new surveying techniques

USGS Publications Warehouse

Mayo, L.R.; Trabant, D.C.

1982-01-01

Knik Glacier in south-central Alaska has the potential to reform Lake George, Alaska 's largest glacier-dammed lake. Measurements of surface altitude, snow depth, terminus position, glacier speed, and ice depth are being made in an attempt to determine the mechanisms that could cause a significant re-advance of the glacier. New surveying and data reduction techniques were developed by the authors and employed successfully at Knik Glacier. These include precise geodetic surveying by the ' trisection ' technique, calculation of surface altitude at a specially-fixed ' index point ' from three point measurements on a rough, moving glacier surface, and calculation of ice thickness from low frequency radar measurements. In addition, this report summarizes the data collected from 1979 to 1981 in support of this goal. (USGS)

Fiber Optic Thermal Health Monitoring of Composites

NASA Technical Reports Server (NTRS)

Wu, Meng-Chou; Winfree, William P.; Moore, Jason P.

2010-01-01

A recently developed technique is presented for thermographic detection of flaws in composite materials by performing temperature measurements with fiber optic Bragg gratings. Individual optical fibers with multiple Bragg gratings employed as surface temperature sensors were bonded to the surfaces of composites with subsurface defects. The investigated structures included a 10-ply composite specimen with subsurface delaminations of various sizes and depths. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The data obtained from grating sensors were analyzed with thermal modeling techniques of conventional thermography to reveal particular characteristics of the interested areas. Results were compared with the calculations using numerical simulation techniques. Methods and limitations for performing in-situ structural health monitoring are discussed.

Recent Advances in Nanodisc Technology for Membrane Proteins Studies (2012–2017)

PubMed Central

Rouck, John; Krapf, John; Roy, Jahnabi; Huff, Hannah; Das, Aditi

2017-01-01

Historically, progress in membrane protein research has been hindered due to solubility issues. The introduction of biomembrane mimetics has since stimulated the field’s momentum. One mimetic, the nanodisc, has proved to be an exceptional system for solubilizing membrane proteins. Herein, we critically evaluate the advantages and imperfections from employing nanodiscs in biophysical and biochemical studies. Specifically, we examine the techniques that have been modified to study membrane proteins in nanodiscs. Techniques discussed include fluorescence microscopy, solution state/solid state NMR, electron microscopy, SAXS, and several mass spectroscopy methods. Newer techniques such as SPR, charge sensitive optical detection, and scintillation proximity assays are also reviewed. Lastly, we cover nanodiscs advancing nanotechnology through nanoplasmonic biosensing, lipoprotein-nanoplatelets, and sortase-mediated labeling of nanodiscs. PMID:28581067

"Selling smarter, not harder": Life course effects on drug sellers' risk perceptions and management.

PubMed

Fader, Jamie J

2016-10-01

Policies undergirding the American War on Drugs assume that drug offenders respond rationally to adjustments in sanction certainty and severity. Previous studies find that instead of absolute deterrence, or the termination of criminal activity, drug offenders employ restrictive deterrence, or a variety of risk management strategies. Extant research and current drug policy both fail to examine the interaction of risk perception, management techniques, and life course events or circumstances. This dynamic examination of apprehension avoidance strategies relies on in-depth interviews mapping out the careers of 20 drug sellers in Philadelphia, Pennsylvania. It examines their risk perceptions and risk management strategies and techniques, exploring rationales for shifts in offending behavior. Respondents were highly risk-averse but used a narrow definition of sanctions relevant to shaping future offending behavior, typically making small adjustments in sales techniques. Rationales for these shifts included sanctions, personal preference, and life course events or circumstances. Only one attributed lasting desistance from offending to a sanction, although life course events such as parenthood and employment were associated with short-term and planned desistance. The limited relevance of sanctions to offenders' thinking about risk avoidance contextualizes the widespread failure of policies designed to deter drug sales. Findings support a growing conclusion that severity of punishment is a less powerful deterrent than certainty and that adjustments in certainty after arrest are offense-specific. The relationship of life course events - especially employment - to desistance and resumed offending suggest that social policies may be more effective than criminal justice sanctions in reducing drug offending. Copyright © 2016 Elsevier B.V. All rights reserved.

Imaging lung perfusion

PubMed Central

Wielpütz, Mark O.; Kauczor, Hans-Ulrich

2012-01-01

From the first measurements of the distribution of pulmonary blood flow using radioactive tracers by West and colleagues (J Clin Invest 40: 1–12, 1961) allowing gravitational differences in pulmonary blood flow to be described, the imaging of pulmonary blood flow has made considerable progress. The researcher employing modern imaging techniques now has the choice of several techniques, including magnetic resonance imaging (MRI), computerized tomography (CT), positron emission tomography (PET), and single photon emission computed tomography (SPECT). These techniques differ in several important ways: the resolution of the measurement, the type of contrast or tag used to image flow, and the amount of ionizing radiation associated with each measurement. In addition, the techniques vary in what is actually measured, whether it is capillary perfusion such as with PET and SPECT, or larger vessel information in addition to capillary perfusion such as with MRI and CT. Combined, these issues affect quantification and interpretation of data as well as the type of experiments possible using different techniques. The goal of this review is to give an overview of the techniques most commonly in use for physiological experiments along with the issues unique to each technique. PMID:22604884

Testing techniques for determining static mechanical properties of Pneumatic tires

NASA Technical Reports Server (NTRS)

Dodge, R. N.; Larson, R. B.; Clark, S. K.; Nybakken, G. H.

1974-01-01

Fore-aft, lateral, and vertical spring rates of model and full-scale pneumatic tires were evaluated by testing techniques generally employed by industry and various testing groups. The purpose of this experimental program was to investigate what effects the different testing techniques have on the measured values of these important static tire mechanical properties. The testing techniques included both incremental and continuous loadings applied at various rates over half, full, and repeated cycles. Of the three properties evaluated, the fore-aft stiffness was demonstrated to be the most affected by the different testing techniques used to obtain it. Appreciable differences in the fore-aft spring rates occurred using both the increment- and continuous-loading techniques; however, the most significant effect was attributed to variations in the size of the fore-aft force loop. The dependence of lateral stiffness values on testing techniques followed the same trends as that for fore-aft stiffness, except to a lesser degree. Vertical stiffness values were found to be nearly independent of testing procedures if the nonlinear portion of the vertical force-deflection curves is avoided.

Secretarial Administraton: The Interviewing Process.

ERIC Educational Resources Information Center

Nemesh, Anna

1979-01-01

Suggests classroom techniques to prepare business students for employment interviews and gives information on lawful and unlawful employment interview inquiries, as well as some fair employment legal requirements of the Equal Employment Opportunity Act of 1974, Civil Rights Act of 1964, Equal Pay Act of 1963, and Rehabilitation Act of 1973. (MF)

The Corrosion Protection of Magnesium Alloy AZ31B

NASA Technical Reports Server (NTRS)

Danford, M. D.; Mendrek, M. J.; Mitchell, M. L.; Torres, P. D.

1997-01-01

Corrosion rates for bare and coated Magnesium alloy AZ31B have been measured. Two coatings, Dow-23(Trademark) and Tagnite(Trademark), have been tested by electrochemical methods and their effectiveness determined. Electrochemical methods employed were the scanning reference electrode technique (SRET), the polarization resistance technique (PR) and the electrochemical impedance spectroscopy technique (EIS). In addition, general corrosion and stress corrosion methods were employed to examine the effectiveness of the above coatings in 90 percent humidity. Results from these studies are presented.

Comparison of X-Ray Micro-Tomography Measurements of Densities and Porosity to Traditional Techniques for Carbon-Carbon Composites

DTIC Science & Technology

2009-02-26

equation, nitrogen , argon, and krypton are employed while for the D-R equation CO2 is usually used . With the adsorption techniques, certain assumption...structure to characterize it. Lastly, other liquids are used in a density gradient column [73-75] employing a sink-float technique in an attempt to...least 147 incremental intrusion pressures to 275 kPa, using nitrogen gas as the displacing medium. The sample is then loaded into the high-pressure

User-Centered Innovation: A Model for "Early Usability Testing."

ERIC Educational Resources Information Center

Sugar, William A.; Boling, Elizabeth

The goal of this study is to show how some concepts and techniques from disciplines outside Instructional Systems Development (ISD) have the potential to extend and enhance the traditional view of ISD practice when they are employed very early in the ISD process. The concepts and techniques employed were user-centered in design and usability, and…

Employ Simulation Techniques. Second Edition. Module C-5 of Category C--Instructional Execution. Professional Teacher Education Module Series.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus. National Center for Research in Vocational Education.

One of a series of performance-based teacher education learning packages focusing upon specific professional competencies of vocational teachers, this learning module deals with employing simulation techniques. It consists of an introduction and four learning experiences. Covered in the first learning experience are various types of simulation…

Endoscopic ultrasound-guided techniques for diagnosing pancreatic mass lesions: Can we do better?

PubMed Central

Storm, Andrew C; Lee, Linda S

2016-01-01

The diagnostic approach to a possible pancreatic mass lesion relies first upon various non-invasive imaging modalities, including computed tomography, ultrasound, and magnetic resonance imaging techniques. Once a suspect lesion has been identified, tissue acquisition for characterization of the lesion is often paramount in developing an individualized therapeutic approach. Given the high prevalence and mortality associated with pancreatic cancer, an ideal approach to diagnosing pancreatic mass lesions would be safe, highly sensitive, and reproducible across various practice settings. Tools, in addition to radiologic imaging, currently employed in the initial evaluation of a patient with a pancreatic mass lesion include serum tumor markers, endoscopic retrograde cholangiopancreatography, and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). EUS-FNA has grown to become the gold standard in tissue diagnosis of pancreatic lesions. PMID:27818584

Materials process and applications of single grain (RE)-Ba-Cu-O bulk high-temperature superconductors

NASA Astrophysics Data System (ADS)

Li, Beizhan; Zhou, Difan; Xu, Kun; Hara, Shogo; Tsuzuki, Keita; Miki, Motohiro; Felder, Brice; Deng, Zigang; Izumi, Mitsuru

2012-11-01

This paper reviews recent advances in the melt process of (RE)-Ba-Cu-O [(RE)BCO, where RE represents a rare earth element] single grain high-temperature superconductors (HTSs), bulks and its applications. The efforts on the improvement of the magnetic flux pinning with employing the top-seeded melt-growth process technique and using a seeded infiltration and growth process are discussed. Which including various chemical doping strategies and controlled pushing effect based on the peritectic reaction of (RE)BCO. The typical experiment results, such as the largest single domain bulk, the clear TEM observations and the significant critical current density, are summarized together with the magnetization techniques. Finally, we highlight the recent prominent progress of HTS bulk applications, including Maglev, flywheel, power device, magnetic drug delivery system and magnetic resonance devices.

Systems Biology in Immunology – A Computational Modeling Perspective

PubMed Central

Germain, Ronald N.; Meier-Schellersheim, Martin; Nita-Lazar, Aleksandra; Fraser, Iain D. C.

2011-01-01

Systems biology is an emerging discipline that combines high-content, multiplexed measurements with informatic and computational modeling methods to better understand biological function at various scales. Here we present a detailed review of the methods used to create computational models and conduct simulations of immune function, We provide descriptions of the key data gathering techniques employed to generate the quantitative and qualitative data required for such modeling and simulation and summarize the progress to date in applying these tools and techniques to questions of immunological interest, including infectious disease. We include comments on what insights modeling can provide that complement information obtained from the more familiar experimental discovery methods used by most investigators and why quantitative methods are needed to eventually produce a better understanding of immune system operation in health and disease. PMID:21219182

"Perspectives on financing population-based health care towards Universal Health Coverage among employed individuals in Ghanzi district, Botswana: A qualitative study".

PubMed

Mbogo, Barnabas Africanus; McGill, Deborah

2016-08-19

Globally, about 150 million people experience catastrophic healthcare expenditure services annually. Among low and middle income countries, out-of-pocket expenditure pushes about 100 million people into poverty annually. In Botswana, 83 % of the general population and 58 % of employed individuals do not have medical aid coverage. Moreover, inequity allocation of financial resources between health services suggests marginalization of population-based health care services (i.e. diseases prevention and health promotion). The purpose of the study is to explore perspectives on employed individuals regarding financing population based health care interventions towards Universal Health Coverage (UHC) in order to make recommendations to the Ministry of Health on health financing options to cover population-based health services. A qualitative design grounded in interpretivist epistemology through social constructivism lens was critical for exploring perspectives of employed individuals. Through purposive and snowballing sampling techniques, a total of 15 respondents including 8 males and 7 females were recruited and interviewed using a semi-structured format. Their age ranged from 23 to 59 years with a median of 36 years. Data was analyzed using Thematic Content Analysis technique. Use of social constructivism lens enabled to classify emerging themes into population coverage, health services coverage and financial protection issues. Despite broad understanding of health coverage schemes among participants, knowledge appears insignificant in increasing enrolment. Participants indicated limited understanding of UHC concepts, however showed willingness to embrace UHC upon brief description. Main thematic issues raised include: exclusion of population-based health services from coverage scheme; disparity in financial protection and health services coverage among enrollees; inability to sustain contracted employees; and systematic exclusion of unemployed individuals and informal sector employees. Increasing enrolment in health coverage schemes requires targeted campaign for information dissemination through use of myriads mass media including: social networks, TV, Radio and others. Moreover, re-designing health insurance schemes is critical in order to include population-based interventions; expand uptake of unemployed and informal sector employees; flexibility in monthly premiums payment plan and use of technology to increase access to payment points. Further study need to evaluate the content of health financing policy in Botswana measured against the World Health Organization Universal Health Coverage conceptual requirements for Low and Middle Income Countries.

Employment program for patients with severe mental illness in Malaysia: a 3-month outcome.

PubMed

Wan Kasim, Syarifah Hafizah; Midin, Marhani; Abu Bakar, Abdul Kadir; Sidi, Hatta; Nik Jaafar, Nik Ruzyanei; Das, Srijit

2014-01-01

This study aimed to examine the rate and predictive factors of successful employment at 3 months upon enrolment into an employment program among patients with severe mental illness (SMI). A cross-sectional study using universal sampling technique was conducted on patients with SMI who completed a 3-month period of being employed at Hospital Permai, Malaysia. A total of 147 patients were approached and 126 were finally included in the statistical analyses. Successful employment was defined as the ability to work 40 or more hours per month. Factors significantly associated with successful employment from bivariate analyses were entered into a multiple logistic regression analysis to identify predictors of successful employment. The rate of successful employment at 3 months was 68.3% (n=81). Significant factors associated with successful employment from bivariate analyses were having past history of working, good family support, less number of psychiatric admissions, good compliance to medicine, good interest in work, living in hostel, being motivated to work, satisfied with the job or salary, getting a preferred job, being in competitive or supported employment and having higher than median scores of PANNS on the positive, negative and general psychopathology. Significant predictors of employment, from a logistic regression model were having good past history of working (p<0.021; OR 6.12; [95% CI 2.1-11.9]) and getting a preferred job (p<0.032; [OR 4.021; 95% CI 1.83-12.1]). Results showed a high employment rate among patients with SMI. Good past history of working and getting a preferred job were significant predictors of successful employment. Copyright © 2014 Elsevier Inc. All rights reserved.

Rapid Prototyping Technologies and their Applications in Prosthodontics, a Review of Literature

PubMed Central

Torabi, Kianoosh; Farjood, Ehsan; Hamedani, Shahram

2015-01-01

The early computer-aided design/computer-aided manufacturing (CAD/CAM) systems were relied exclusively on subtractive methods. In recent years, additive methods by employing rapid prototyping (RP) have progressed rapidly in various fields of dentistry as they have the potential to overcome known drawbacks of subtractive techniques such as fit problems. RP techniques have been exploited to build complex 3D models in medicine since the 1990s. RP has recently proposed successful applications in various dental fields, such as fabrication of implant surgical guides, frameworks for fixed and removable partial dentures, wax patterns for the dental prosthesis, zirconia prosthesis and molds for metal castings, and maxillofacial prosthesis and finally, complete dentures. This paper aimed to offer a comprehensive literature review of various RP methods, particularly in dentistry, that are expected to bring many improvements to the field. A search was made through MEDLINE database and Google scholar search engine. The keywords; ‘rapid prototyping’ and ‘dentistry’ were searched in title/abstract of publications; limited to 2003 to 2013, concerning past decade. The inclusion criterion was the technical researches that predominately included laboratory procedures. The exclusion criterion was meticulous clinical and excessive technical procedures. A total of 106 articles were retrieved, recited by authors and only 50 met the specified inclusion criteria for this review. Selected articles had used rapid prototyping techniques in various fields in dentistry through different techniques. This review depicted the different laboratory procedures employed in this method and confirmed that RP technique have been substantially feasible in dentistry. With advancement in various RP systems, it is possible to benefit from this technique in different dental practices, particularly in implementing dental prostheses for different applications. PMID:25759851

Expediting red blood cell transfusions by syringing causes significant hemolysis.

PubMed

De Villiers, Willem Lambertus; Murray, Adriaan Albertus; Levin, Andrew Ian

2017-11-01

Techniques commonly used to expedite blood transfusions include pneumatically pressurizing red blood cell (RBC) bags or manual syringing its contents. We compared these techniques on RBC hemolysis using a simulated transfusion model. Fifteen warmed RBC units that were 12.3 ± 4.3 (95% confidence interval [CI], 10.1-14.5) days old were each subjected to two experimental rapid transfusion techniques. RBCs from each technique were directed through 18- and 22-gauge cannulas attached to blood administration sets. One technique involved RBC bag pressurization to 300 mmHg. The other employed a 20-mL syringe to effect forceful, manual aspiration from the RBC bag followed by forceful, manual RBC injection. The control group was gravity driven without cannulas. Free hemoglobin (Hb) concentrations were measured and percent hemolysis was calculated. Free Hb concentrations and percent hemolysis (median [95% CI]) were similar in the control (0.05 [0.03-0.08] g/dL and 0.13% [0.09%-0.17%], respectively) and pressurized experiments (0.06 [0.05-0.09] g/dL; 0.14% [0.12%-0.22%]), respectively. Syringing resulted in 10-fold higher free Hb concentrations (0.55 [0.38-0.92] g/dL) and percent hemolysis (1.28% [1.03%-2.15%]) than when employing the control (p < 0.0001) or pressurization (p < 0.0001) techniques. Cannula sizes studied did not affect hemolysis. Forceful manual syringing caused significant hemolysis and high free Hb concentrations. Pressurizing RBC bags induced no more hemolysis than after gravity-facilitated transfusions. Syringing to expedite RBC transfusions should be avoided in favor of pneumatic RBC bag pressurization. © 2017 AABB.

Rapid Prototyping Technologies and their Applications in Prosthodontics, a Review of Literature.

PubMed

Torabi, Kianoosh; Farjood, Ehsan; Hamedani, Shahram

2015-03-01

The early computer-aided design/computer-aided manufacturing (CAD/CAM) systems were relied exclusively on subtractive methods. In recent years, additive methods by employing rapid prototyping (RP) have progressed rapidly in various fields of dentistry as they have the potential to overcome known drawbacks of subtractive techniques such as fit problems. RP techniques have been exploited to build complex 3D models in medicine since the 1990s. RP has recently proposed successful applications in various dental fields, such as fabrication of implant surgical guides, frameworks for fixed and removable partial dentures, wax patterns for the dental prosthesis, zirconia prosthesis and molds for metal castings, and maxillofacial prosthesis and finally, complete dentures. This paper aimed to offer a comprehensive literature review of various RP methods, particularly in dentistry, that are expected to bring many improvements to the field. A search was made through MEDLINE database and Google scholar search engine. The keywords; 'rapid prototyping' and 'dentistry' were searched in title/abstract of publications; limited to 2003 to 2013, concerning past decade. The inclusion criterion was the technical researches that predominately included laboratory procedures. The exclusion criterion was meticulous clinical and excessive technical procedures. A total of 106 articles were retrieved, recited by authors and only 50 met the specified inclusion criteria for this review. Selected articles had used rapid prototyping techniques in various fields in dentistry through different techniques. This review depicted the different laboratory procedures employed in this method and confirmed that RP technique have been substantially feasible in dentistry. With advancement in various RP systems, it is possible to benefit from this technique in different dental practices, particularly in implementing dental prostheses for different applications.

IGA: A Simplified Introduction and Implementation Details for Finite Element Users

NASA Astrophysics Data System (ADS)

Agrawal, Vishal; Gautam, Sachin S.

2018-05-01

Isogeometric analysis (IGA) is a recently introduced technique that employs the Computer Aided Design (CAD) concept of Non-uniform Rational B-splines (NURBS) tool to bridge the substantial bottleneck between the CAD and finite element analysis (FEA) fields. The simplified transition of exact CAD models into the analysis alleviates the issues originating from geometrical discontinuities and thus, significantly reduces the design-to-analysis time in comparison to traditional FEA technique. Since its origination, the research in the field of IGA is accelerating and has been applied to various problems. However, the employment of CAD tools in the area of FEA invokes the need of adapting the existing implementation procedure for the framework of IGA. Also, the usage of IGA requires the in-depth knowledge of both the CAD and FEA fields. This can be overwhelming for a beginner in IGA. Hence, in this paper, a simplified introduction and implementation details for the incorporation of NURBS based IGA technique within the existing FEA code is presented. It is shown that with little modifications, the available standard code structure of FEA can be adapted for IGA. For the clear and concise explanation of these modifications, step-by-step implementation of a benchmark plate with a circular hole under the action of in-plane tension is included.

Electronically nonadiabatic wave packet propagation using frozen Gaussian scattering

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

Kondorskiy, Alexey D., E-mail: kondor@sci.lebedev.ru; Nanbu, Shinkoh, E-mail: shinkoh.nanbu@sophia.ac.jp

2015-09-21

We present an approach, which allows to employ the adiabatic wave packet propagation technique and semiclassical theory to treat the nonadiabatic processes by using trajectory hopping. The approach developed generates a bunch of hopping trajectories and gives all additional information to incorporate the effect of nonadiabatic coupling into the wave packet dynamics. This provides an interface between a general adiabatic frozen Gaussian wave packet propagation method and the trajectory surface hopping technique. The basic idea suggested in [A. D. Kondorskiy and H. Nakamura, J. Chem. Phys. 120, 8937 (2004)] is revisited and complemented in the present work by the elaborationmore » of efficient numerical algorithms. We combine our approach with the adiabatic Herman-Kluk frozen Gaussian approximation. The efficiency and accuracy of the resulting method is demonstrated by applying it to popular benchmark model systems including three Tully’s models and 24D model of pyrazine. It is shown that photoabsorption spectrum is successfully reproduced by using a few hundreds of trajectories. We employ the compact finite difference Hessian update scheme to consider feasibility of the ab initio “on-the-fly” simulations. It is found that this technique allows us to obtain the reliable final results using several Hessian matrix calculations per trajectory.« less

Experimental and data analysis techniques for deducing collision-induced forces from photographic histories of engine rotor fragment impact/interaction with a containment ring

NASA Technical Reports Server (NTRS)

Yeghiayan, R. P.; Leech, J. W.; Witmer, E. A.

1973-01-01

An analysis method termed TEJ-JET is described whereby measured transient elastic and inelastic deformations of an engine-rotor fragment-impacted structural ring are analyzed to deduce the transient external forces experienced by that ring as a result of fragment impact and interaction with the ring. Although the theoretical feasibility of the TEJ-JET concept was established, its practical feasibility when utilizing experimental measurements of limited precision and accuracy remains to be established. The experimental equipment and the techniques (high-speed motion photography) employed to measure the transient deformations of fragment-impacted rings are described. Sources of error and data uncertainties are identified. Techniques employed to reduce data reading uncertainties and to correct the data for optical-distortion effects are discussed. These procedures, including spatial smoothing of the deformed ring shape by Fourier series and timewise smoothing by Gram polynomials, are applied illustratively to recent measurements involving the impact of a single T58 turbine rotor blade against an aluminum containment ring. Plausible predictions of the fragment-ring impact/interaction forces are obtained by one branch of this TEJ-JET method; however, a second branch of this method, which provides an independent estimate of these forces, remains to be evaluated.

Changing strategies of the retrograde approach for chronic total occlusion during the past 7 years.

PubMed

Muramatsu, Toshiya; Tsukahara, Reiko; Ito, Yoshiaki; Ishimori, Hiroshi; Park, Seung-Jung; de Winter, Robert; Shokry, Khaled; Wang, Lefeng; Chen, Jiyan; Wang, Haichang

2013-03-01

We reviewed the technical changes and results achieved with the retrograde approach since we introduced it 7 years ago. The subjects were 1,268 patients who were treated for CTO between January 2004 and December 2010. They were investigated with respect to the success rate, the frequency of employing the retrograde approach and its outcome, and other factors. The retrograde approach was employed in ∼30% of chronic total occlusion (CTO) patients (n = 281) and the retrograde guidewire success rate was 81.1%. The kissing wire technique was substituted for the retrograde approach in 126 of the 281 patients, with antegrade crossing of a guidewire being successful in 88 of them (70%). The retrograde approach was combined with the CART and reverse controlled antegrade retrograde tracking (CART) techniques in 22 and 21 patients, respectively. Among 83 patients treated with Corsair catheters, crossing of the CTO was achieved in 63. The overall procedural success rate was 79.7% (224 patients). Complications of the retrograde approach included collateral channel dissection (2.1%), channel perforation (1.7%), CTO perforation (1.7%), and donor artery occlusion (1.1%). The success rate and safety of the retrograde approach are both satisfactory if the appropriate devices and techniques are selected. Copyright © 2012 Wiley Periodicals, Inc.

The contemporary role of 1 vs. 2-stage repair for proximal hypospadias

PubMed Central

Dason, Shawn; Wong, Nathan

2014-01-01

This review discusses the most commonly employed techniques in the repair of proximal hypospadias, highlighting the advantages and disadvantages of single versus staged surgical techniques. Hypospadias can have a spectrum of severity with a urethral meatus ranging from the perineum to the glans. Associated abnormalities are commonly found with proximal hypospadias and encompass a large spectrum, including ventral curvature (VC) up to 50 degrees or more, ventral skin deficiency, a flattened glans, penile torsion and penoscrotal transposition. Our contemporary understanding of hypospadiology is comprised of a foundation built by experts who have described a number of techniques and their outcomes, combined with survey data detailing practice patterns. The two largest components of hypospadias repair include repair of VC and urethroplasty. VC greater than 20 degrees is considered clinically relevant to warrant surgical correction. To repair VC, the penis is first degloved—a procedure that may reduce or remove curvature by itself in some cases. Residual curvature is then repaired with dorsal plication techniques, transection of the urethral plate, and/or ventral lengthening techniques. Urethroplasty takes the form of 1- or 2-stage repairs. One-stage options include the tubularized incised urethroplasty (TIP) or various graft or flap-based techniques. Two-stage options also include grafts or flaps, including oral mucosal and preputial skin grafting. One stage repairs are an attractive option in that they may reduce cost, hospital stay, anesthetic risks, and time to the final result. The downside is that these repairs require mastery of multiple techniques may be more complex, and—depending on technique—have higher complication rates. Two-stage repairs are preferred by the majority of surveyed hypospadiologists. The 2-stage repair is versatile and has satisfactory outcomes, but necessitates a second procedure. Given the lack of clear high-quality evidence supporting the superiority of one approach over the others, hypospadiologists should develop their own algorithm, which gives them the best outcomes. PMID:26813851

Ultrasonic characterization of granites obtained from industrial quarries of Extremadura (Spain).

PubMed

del Río, L M; López, F; Esteban, F J; Tejado, J J; Mota, M; González, I; San Emeterio, J L; Ramos, A

2006-12-22

The industry of ornamental rocks, such as granites, represents one of the most important industrial activities in the region of Extremadura, SW Spain. A detailed knowledge of the intrinsic properties of this natural stone and its environmental evolution is a required goal in order to fully characterize its quality. In this work, two independent NDT acoustic techniques have been used to measure the acoustic velocity of longitudinal waves in different prismatic granitic-samples of industrial quarries. A low-frequency transceiver set-up, based on a high-voltage BPV Steinkamp instrument and two 50 kHz probes, has been used to measure pulse travel times by ultrasonic through-transmission testing. In complementary fashion, an Erudite MK3 test equipment with an electromagnetic vibrator and two piezoelectric sensors has also been employed to measure ultrasonic velocity by means of a resonance-based method, using the same types of granite varieties. In addition, a comprehensive set of physical/mechanical properties have also been analyzed, according to Spanish regulations in force, by means of alternative methods including destructive techniques such as strength, porosity, absorption, etc. A large number of samples, representing the most important varieties of granites from quarries of Extremadura, have been analyzed using the above-mentioned procedures. Some results obtained by destructive techniques have been correlated with those found using ultrasonic techniques. Our experimental setting allowed a complementary characterization of granite samples and a thorough validation of the different techniques employed, thus providing the industry of ornamental rocks with a non-destructive tool that will facilitate a more detailed insight on the properties of the rocks under study.

Verification Techniques for Parameter Selection and Bayesian Model Calibration Presented for an HIV Model

NASA Astrophysics Data System (ADS)

Wentworth, Mami Tonoe

Uncertainty quantification plays an important role when making predictive estimates of model responses. In this context, uncertainty quantification is defined as quantifying and reducing uncertainties, and the objective is to quantify uncertainties in parameter, model and measurements, and propagate the uncertainties through the model, so that one can make a predictive estimate with quantified uncertainties. Two of the aspects of uncertainty quantification that must be performed prior to propagating uncertainties are model calibration and parameter selection. There are several efficient techniques for these processes; however, the accuracy of these methods are often not verified. This is the motivation for our work, and in this dissertation, we present and illustrate verification frameworks for model calibration and parameter selection in the context of biological and physical models. First, HIV models, developed and improved by [2, 3, 8], describe the viral infection dynamics of an HIV disease. These are also used to make predictive estimates of viral loads and T-cell counts and to construct an optimal control for drug therapy. Estimating input parameters is an essential step prior to uncertainty quantification. However, not all the parameters are identifiable, implying that they cannot be uniquely determined by the observations. These unidentifiable parameters can be partially removed by performing parameter selection, a process in which parameters that have minimal impacts on the model response are determined. We provide verification techniques for Bayesian model calibration and parameter selection for an HIV model. As an example of a physical model, we employ a heat model with experimental measurements presented in [10]. A steady-state heat model represents a prototypical behavior for heat conduction and diffusion process involved in a thermal-hydraulic model, which is a part of nuclear reactor models. We employ this simple heat model to illustrate verification techniques for model calibration. For Bayesian model calibration, we employ adaptive Metropolis algorithms to construct densities for input parameters in the heat model and the HIV model. To quantify the uncertainty in the parameters, we employ two MCMC algorithms: Delayed Rejection Adaptive Metropolis (DRAM) [33] and Differential Evolution Adaptive Metropolis (DREAM) [66, 68]. The densities obtained using these methods are compared to those obtained through the direct numerical evaluation of the Bayes' formula. We also combine uncertainties in input parameters and measurement errors to construct predictive estimates for a model response. A significant emphasis is on the development and illustration of techniques to verify the accuracy of sampling-based Metropolis algorithms. We verify the accuracy of DRAM and DREAM by comparing chains, densities and correlations obtained using DRAM, DREAM and the direct evaluation of Bayes formula. We also perform similar analysis for credible and prediction intervals for responses. Once the parameters are estimated, we employ energy statistics test [63, 64] to compare the densities obtained by different methods for the HIV model. The energy statistics are used to test the equality of distributions. We also consider parameter selection and verification techniques for models having one or more parameters that are noninfluential in the sense that they minimally impact model outputs. We illustrate these techniques for a dynamic HIV model but note that the parameter selection and verification framework is applicable to a wide range of biological and physical models. To accommodate the nonlinear input to output relations, which are typical for such models, we focus on global sensitivity analysis techniques, including those based on partial correlations, Sobol indices based on second-order model representations, and Morris indices, as well as a parameter selection technique based on standard errors. A significant objective is to provide verification strategies to assess the accuracy of those techniques, which we illustrate in the context of the HIV model. Finally, we examine active subspace methods as an alternative to parameter subset selection techniques. The objective of active subspace methods is to determine the subspace of inputs that most strongly affect the model response, and to reduce the dimension of the input space. The major difference between active subspace methods and parameter selection techniques is that parameter selection identifies influential parameters whereas subspace selection identifies a linear combination of parameters that impacts the model responses significantly. We employ active subspace methods discussed in [22] for the HIV model and present a verification that the active subspace successfully reduces the input dimensions.

The Lie Detector in Employment; An Examination of Some of the Problems. Key Issues Series. Number 2.

ERIC Educational Resources Information Center

Coghill, Mary Ann; Gruenfeld, Elaine F.

In a review of personnel polygraphing, the history of the polygraph technique is discussed. Since it is a controversial technique used by employers to test employees' honesty and loyalty by measuring physiological reactions, an increasing number of States and localities are taking legal action to prevent its use. The results of several arbitration…

Inverse Problems in Geodynamics Using Machine Learning Algorithms

NASA Astrophysics Data System (ADS)

Shahnas, M. H.; Yuen, D. A.; Pysklywec, R. N.

2018-01-01

During the past few decades numerical studies have been widely employed to explore the style of circulation and mixing in the mantle of Earth and other planets. However, in geodynamical studies there are many properties from mineral physics, geochemistry, and petrology in these numerical models. Machine learning, as a computational statistic-related technique and a subfield of artificial intelligence, has rapidly emerged recently in many fields of sciences and engineering. We focus here on the application of supervised machine learning (SML) algorithms in predictions of mantle flow processes. Specifically, we emphasize on estimating mantle properties by employing machine learning techniques in solving an inverse problem. Using snapshots of numerical convection models as training samples, we enable machine learning models to determine the magnitude of the spin transition-induced density anomalies that can cause flow stagnation at midmantle depths. Employing support vector machine algorithms, we show that SML techniques can successfully predict the magnitude of mantle density anomalies and can also be used in characterizing mantle flow patterns. The technique can be extended to more complex geodynamic problems in mantle dynamics by employing deep learning algorithms for putting constraints on properties such as viscosity, elastic parameters, and the nature of thermal and chemical anomalies.

Military applications and examples of near-surface seismic surface wave methods (Invited)

NASA Astrophysics Data System (ADS)

sloan, S.; Stevens, R.

2013-12-01

Although not always widely known or publicized, the military uses a variety of geophysical methods for a wide range of applications--some that are already common practice in the industry while others are truly novel. Some of those applications include unexploded ordnance detection, general site characterization, anomaly detection, countering improvised explosive devices (IEDs), and security monitoring, to name a few. Techniques used may include, but are not limited to, ground penetrating radar, seismic, electrical, gravity, and electromagnetic methods. Seismic methods employed include surface wave analysis, refraction tomography, and high-resolution reflection methods. Although the military employs geophysical methods, that does not necessarily mean that those methods enable or support combat operations--often times they are being used for humanitarian applications within the military's area of operations to support local populations. The work presented here will focus on the applied use of seismic surface wave methods, including multichannel analysis of surface waves (MASW) and backscattered surface waves, often in conjunction with other methods such as refraction tomography or body-wave diffraction analysis. Multiple field examples will be shown, including explosives testing, tunnel detection, pre-construction site characterization, and cavity detection.

Mu-2 ranging

NASA Technical Reports Server (NTRS)

Martin, W. L.; Zygielbaum, A. I.

1977-01-01

The Mu-II Dual-Channel Sequential Ranging System designed as a model for future Deep Space Network ranging equipment is described. A list of design objectives is followed by a theoretical explanation of the digital demodulation techniques first employed in this machine. Hardware and software implementation are discussed, together with the details relating to the construction of the device. Two appendixes are included relating to the programming and operation of this equipment to yield the maximum scientific data.

The Monitoring, Detection, Isolation and Assessment of Information Warfare Attacks Through Multi-Level, Multi-Scale System Modeling and Model Based Technology

DTIC Science & Technology

2004-01-01

login identity to the one under which the system call is executed, the parameters of the system call execution - file names including full path...Anomaly detection COAST-EIMDT Distributed on target hosts EMERALD Distributed on target hosts and security servers Signature recognition Anomaly...uses a centralized architecture, and employs an anomaly detection technique for intrusion detection. The EMERALD project [80] proposes a

Early Adolescence to Early Adulthood: Volume 5, The Best of ACLD. Selected Papers from the International Conference of the Association for Children and Adults with Learning Disabilities (20th, Washington, District of Columbia, 1983). First Edition.

ERIC Educational Resources Information Center

Cruickshank, William M., Ed.; Kliebhan, Joanne Marie, Ed.

Fifteen author-contributed papers focus on the learning disabled adolescent and young adult. The first section provides a general overview while subsequent sections address educational and social techniques, steps to employment, and programs for adolescents. The following titles and authors are included: "Prevention: Primary, Secondary, or…

Development of a Very Dense Liquid Cooled Compute Platform

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

Hughes, Phillip N.; Lipp, Robert J.

2013-12-10

The objective of this project was to design and develop a prototype very energy efficient high density compute platform with 100% pumped refrigerant liquid cooling using commodity components and high volume manufacturing techniques. Testing at SLAC has indicated that we achieved a DCIE of 0.93 against our original goal of 0.85. This number includes both cooling and power supply and was achieved employing some of the highest wattage processors available.

Prevention of the Posttraumatic Fibrotic Response in Joints

DTIC Science & Technology

2015-10-01

surgical procedures and subsequent collection of tissues have been developed and are currently used on a regular basis. Major Task 4: Evaluating the...needed to evaluate the utility of the inhibitory antibody to reduce the flexion contracture of injured knee joints. The employed techniques include...second surgery to remove a pin, and it did not change by the end of the 32nd week 1. Major Task 5: Task 4. Data analysis and statistical evaluation

Fundamental Flame Velocities of Pure Hydrocarbons I : Alkanes, Alkenes, Alkynes Benzene, and Cyclohexane

NASA Technical Reports Server (NTRS)

Gerstein, Melvin; Levine, Oscar; Wong, Edgar L

1950-01-01

The flame velocities of 37 pure hydrocarbons including normal and branched alkanes, alkenes, and alkynes; as well as benzene and cyclohexane, together with the experimental technique employed are presented. The normal alkanes have about the same flame velocity from ethane through heptane with methane being about 16 percent lower. Unsaturation increases the flame velocity in the order of alkanes, alkenes, and alkynes. Branching reduces the flame velocity.

Nonequilibrium flow computations. 1: An analysis of numerical formulations of conservation laws

NASA Technical Reports Server (NTRS)

Liu, Yen; Vinokur, Marcel

1988-01-01

Modern numerical techniques employing properties of flux Jacobian matrices are extended to general, nonequilibrium flows. Generalizations of the Beam-Warming scheme, Steger-Warming and van Leer Flux-vector splittings, and Roe's approximate Riemann solver are presented for 3-D, time-varying grids. The analysis is based on a thermodynamic model that includes the most general thermal and chemical nonequilibrium flow of an arbitrary gas. Various special cases are also discussed.

Guide to Competency-Based Education for Business and Office Occupations. A Catalog of Bookkeeping/Accounting, Clerical/Secretarial, and Data Processing Skills Which Your Students Need to Get a Job and to Keep It.

ERIC Educational Resources Information Center

New Mexico State Dept. of Education; Santa Fe. Div. of Vocational Education.

This curriculum guide was developed to help administrators develop a competency-based postsecondary curriculum to prepare students for employment in business and office occupations. The content is in five sections. The first one introduces the concepts and techniques of competency-based education and includes some sample forms, such as student…

Current process in hearing-aid fitting appointments: An analysis of audiologists' use of behaviour change techniques using the behaviour change technique taxonomy (v1).

PubMed

Barker, Fiona; Mackenzie, Emma; de Lusignan, Simon

2016-11-01

To observe and analyse the range and nature of behaviour change techniques (BCTs) employed by audiologists during hearing-aid fitting consultations to encourage and enable hearing-aid use. Non-participant observation and qualitative thematic analysis using the behaviour change technique taxonomy (version 1) (BCTTv1). Ten consultations across five English NHS audiology departments. Audiologists engage in behaviours to ensure the hearing-aid is fitted to prescription and is comfortable to wear. They provide information, equipment, and training in how to use a hearing-aid including changing batteries, cleaning, and maintenance. There is scope for audiologists to use additional BCTs: collaborating with patients to develop a behavioural plan for hearing-aid use that includes goal-setting, action-planning and problem-solving; involving significant others; providing information on the benefits of hearing-aid use or the consequences of non-use and giving advice about using prompts/cues for hearing-aid use. This observational study of audiologist behaviour in hearing-aid fitting consultations has identified opportunities to use additional behaviour change techniques that might encourage hearing-aid use. This information defines potential intervention targets for further research with the aim of improving hearing-aid use amongst adults with acquired hearing loss.

Total Reconstruction of the Auricle: Our Experiences on Indications and Recent Techniques

PubMed Central

Storck, K.; Staudenmaier, R.; Buchberger, M.; Strenger, T.; Kreutzer, K.; von Bomhard, A.; Stark, T.

2014-01-01

Introduction. Auricular reconstruction is a great challenge in facial plastic surgery. With the advances in surgical techniques and biotechnology, different options are available for consideration. The aim of this paper is to review the knowledge about the various techniques for total auricular reconstruction based on the literature and our experience. Methods. Approximately 179 articles published from 1980 to 2013 were identified, and 59 articles were included. We have focused on the current status of total auricular reconstruction based on our personal experience and on papers of particular interest, published within the period of review. We have also included a prospective view on the tissue engineering of cartilage. Results. Most surgeons still practice total auricular reconstruction by employing techniques developed by Brent, Nagata, and Firmin with autologous rib cartilage. Within the last years, alloplastic frameworks for reconstruction have become well established. Choosing the reconstruction techniques depends mainly on the surgeon's preference and experience. Prosthetic reconstruction is still reserved for special conditions, even though the material is constantly improving. Tissue engineering has a growing potential for clinical applicability. Conclusion. Auricular reconstruction still receives attention of plastic/maxillofacial surgeons and otolaryngologists. Even though clinical applicability lags behind initial expectations, the development of tissue-engineered constructs continues its potential development. PMID:24822198

Impact of Next Generation Sequencing Techniques in Food Microbiology

PubMed Central

Mayo, Baltasar; Rachid, Caio T. C. C; Alegría, Ángel; Leite, Analy M. O; Peixoto, Raquel S; Delgado, Susana

2014-01-01

Understanding the Maxam-Gilbert and Sanger sequencing as the first generation, in recent years there has been an explosion of newly-developed sequencing strategies, which are usually referred to as next generation sequencing (NGS) techniques. NGS techniques have high-throughputs and produce thousands or even millions of sequences at the same time. These sequences allow for the accurate identification of microbial taxa, including uncultivable organisms and those present in small numbers. In specific applications, NGS provides a complete inventory of all microbial operons and genes present or being expressed under different study conditions. NGS techniques are revolutionizing the field of microbial ecology and have recently been used to examine several food ecosystems. After a short introduction to the most common NGS systems and platforms, this review addresses how NGS techniques have been employed in the study of food microbiota and food fermentations, and discusses their limits and perspectives. The most important findings are reviewed, including those made in the study of the microbiota of milk, fermented dairy products, and plant-, meat- and fish-derived fermented foods. The knowledge that can be gained on microbial diversity, population structure and population dynamics via the use of these technologies could be vital in improving the monitoring and manipulation of foods and fermented food products. They should also improve their safety. PMID:25132799

Guided Wave Sensing In a Carbon Steel Pipe Using a Laser Vibrometer System

NASA Astrophysics Data System (ADS)

Ruíz Toledo, Abelardo; Salazar Soler, Jordi; Chávez Domínguez, Juan Antonio; García Hernández, Miguel Jesús; Turó Peroy, Antoni

2010-05-01

Non-Destructive Evaluation (NDE) techniques have achieved a great development during the last decades as a valuable tool for material characterization, manufacturing control and structural integrity tests. Among these tools, the guided wave technology has been rapidly extended because it reduces inspection time and costs compared to the ordinary point by point testing in large structures, as well as because of the possibility of inspecting under insulation and coating conditions. This fast development has motivated the creation of several inspection and material characterization systems including different technologies which can be combined with this technique. Different measurements systems based on laser techniques have been presented in order to inspect pipes, plates and diverse structures. Many of them are experimental systems of high cost and complexity which combine the employment of a laser for generation of waves in the structure and an interferometer for detection. Some of them employ air-coupled ultrasound generation transducers, with high losses in air and which demand high energy for exciting waves in materials of high stiffness. The combined employment of a commercial vibrometer system for Lamb wave sensing in plates has been successfully shown in the literature. In this paper we present a measurement system based on the combined employment of a piezoelectric wedge transducer and a laser vibrometer to sense guided acoustic waves in carbon steel pipes. The measurement system here presented is mainly compounded of an angular wedge transducer, employed to generate the guided wave and a commercial laser vibrometer used in the detection process. The wedge transducer is excited by means of a signal function generator whose output signal has been amplified with a power signal amplifier. A high precision positioning system is employed to place the laser beam at different points through the pipe surface. The signal detected by the laser vibrometer system is amplified with a signal amplifier and then it is displayed in a digital storage oscilloscope. This set-up offers the possibility of analyzing in a simpler way the wave propagation and the material evaluation in pipes of certain wall thickness. The material characterization considering distinct wave propagation modes can be easily achieved, changing the different incident angles of the wedge piezoelectric probe and their combined employment with several driving signals. Moreover, this experimental sensing system offers other possibilities of inspecting and analyzing the wave propagation in some features (bends, flange joints, welds,…) of the pipe surface which cause very large reflections and mode conversions and which in practice limits the inspection range when are inspected with conventional receiving transducer arrangements.

77 FR 25225 - 60-Day Notice of Proposed Information Collection: DS 7655, Iraqi Citizens and Nationals Employed...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-27

... the use of automated collection techniques or other forms of technology. Abstract of Proposed..., date(s) of employment, biometric, and other data must be collected and used to verify employment for...

Multivariate analysis of remote LIBS spectra using partial least squares, principal component analysis, and related techniques

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

Clegg, Samuel M; Barefield, James E; Wiens, Roger C

2008-01-01

Quantitative analysis with LIBS traditionally employs calibration curves that are complicated by the chemical matrix effects. These chemical matrix effects influence the LIBS plasma and the ratio of elemental composition to elemental emission line intensity. Consequently, LIBS calibration typically requires a priori knowledge of the unknown, in order for a series of calibration standards similar to the unknown to be employed. In this paper, three new Multivariate Analysis (MV A) techniques are employed to analyze the LIBS spectra of 18 disparate igneous and highly-metamorphosed rock samples. Partial Least Squares (PLS) analysis is used to generate a calibration model from whichmore » unknown samples can be analyzed. Principal Components Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA) are employed to generate a model and predict the rock type of the samples. These MV A techniques appear to exploit the matrix effects associated with the chemistries of these 18 samples.« less

Free-space quantum key distribution at night

NASA Astrophysics Data System (ADS)

Buttler, William T.; Hughes, Richard J.; Kwiat, Paul G.; Lamoreaux, Steve K.; Luther, Gabriel G.; Morgan, George L.; Nordholt, Jane E.; Peterson, C. Glen; Simmons, Charles M.

1998-07-01

An experimental free-space quantum key distribution (QKD) system has been tested over an outdoor optical path of approximately 1 km under nighttime conditions at Los Alamos National Laboratory. This system employs the Bennett 92 protocol; here we give a brief overview of this protocol, and describe our experimental implementation of it. An analysis of the system efficiency is presented as well as a description of our error detection protocol, which employs a 2D parity check scheme. Finally, the susceptibility of this system to eavesdropping by various techniques is determined, and the effectiveness of privacy amplification procedures is discussed. Our conclusions are that free-space QKD is both effective and secure; possible applications include the rekeying of satellites in low earth orbit.

Recent developments in low cost silicon solar cells for terrestrial applications. [sheet production methods

NASA Technical Reports Server (NTRS)

Leipold, M. H.

1978-01-01

A variety of techniques may be used for photovoltaic energy systems. Concentrated or not concentrated sunlight may be employed, and a number of materials can be used, including silicon, gallium arsenide, cadmium sulfide, and cadmium telluride. Most of the experience, however, has been obtained with silicon cells employed without sunlight concentration. An industrial base exists at present for producing solar cells at a price in the range from $15 to $30 per peak watt. A major federal program has the objective to reduce the price of power provided by silicon solar systems to approximately $1 per peak watt in the early 1980's and $0.50 per watt by 1986. The approaches considered for achieving this objective are discussed.

Tetrahedron Formation Control

NASA Technical Reports Server (NTRS)

Petruzzo, Charles; Guzman, Jose

2004-01-01

This paper considers the preliminary development of a general optimization procedure for tetrahedron formation control. The maneuvers are assumed to be impulsive and a multi-stage optimization method is employed. The stages include (1) targeting to a fixed tetrahedron location and orientation, and (2) rotating and translating the tetrahedron. The number of impulsive maneuvers can also be varied. As the impulse locations and times change, new arcs are computed using a differential corrections scheme that varies the impulse magnitudes and directions. The result is a continuous trajectory with velocity discontinuities. The velocity discontinuities are then used to formulate the cost function. Direct optimization techniques are employed. The procedure is applied to the NASA Goddard Magnetospheric Multi-Scale (MMS) mission to compute preliminary formation control fuel requirements.

Optimality study of a gust alleviation system for light wing-loading STOL aircraft

NASA Technical Reports Server (NTRS)

Komoda, M.

1976-01-01

An analytical study was made of an optimal gust alleviation system that employs a vertical gust sensor mounted forward of an aircraft's center of gravity. Frequency domain optimization techniques were employed to synthesize the optimal filters that process the corrective signals to the flaps and elevator actuators. Special attention was given to evaluating the effectiveness of lead time, that is, the time by which relative wind sensor information should lead the actual encounter of the gust. The resulting filter is expressed as an implicit function of the prescribed control cost. A numerical example for a light wing loading STOL aircraft is included in which the optimal trade-off between performance and control cost is systematically studied.

A scoping review of qualitative research in peer-reviewed dental publications.

PubMed

Gussy, M; Dickson-Swift, V; Adams, J

2013-08-01

Qualitative research designs are being used increasingly in dental research. This paper describes the extent and range of dental research in which qualitative methods have been employed as well as the techniques of data collection and analysis preferred by dental researchers. A scoping review was conducted to locate studies published in dental journals, which reported the use of qualitative methods. Data concerning the focus of the research and the reported qualitative techniques were extracted. Studies included in the review totalled 197. The majority of qualitative research captured in this scoping study focussed on three main areas: dental education, professional dental and dental educators' activities and experiences and the patient/public perceptions. Interviews and focus group discussions were the most commonly selected techniques for data collection. The majority of the studies included in the scoping review had a focus on education of dental professionals the activities of dental professionals or the reported perceptions of or experiences with dental services by patients or members of the public. Little research was located, which explored peoples' personal experience of dental conditions. Research reported in dental publications has a heavy bias towards the use of focus groups and interview data collection techniques. © 2012 John Wiley & Sons A/S.

Dual-surface dielectric depth detector for holographic millimeter-wave security scanners

NASA Astrophysics Data System (ADS)

McMakin, Douglas L.; Keller, Paul E.; Sheen, David M.; Hall, Thomas E.

2009-05-01

The Transportation Security Administration (TSA) is presently deploying millimeter-wave whole body scanners at over 20 airports in the United States. Threats that may be concealed on a person are displayed to the security operator of this scanner. "Passenger privacy is ensured through the anonymity of the image. The officer attending the passenger cannot view the image, and the officer viewing the image is remotely located and cannot see the passenger. Additionally, the image cannot be stored, transmitted or printed and is deleted immediately after being viewed. Finally, the facial area of the image has been blurred to further ensure privacy." Pacific Northwest National Laboratory (PNNL) originated research into this novel security technology which has been independently commercialized by L-3 Communications, SafeView, Inc. PNNL continues to perform fundamental research into improved software techniques which are applicable to the field of holographic security screening technology. This includes performing significant research to remove human features from the imagery. Both physical and software imaging techniques have been employed. The physical imaging techniques include polarization diversity illumination and reception, dual frequency implementation, and high frequency imaging at 100 GHz. This paper will focus on a software privacy technique using a dual surface dielectric depth detector method.

NeuroPhysics: Studying how neurons create the perception of space-time using Physics' tools and techniques

NASA Astrophysics Data System (ADS)

Dhingra, Shonali; Sandler, Roman; Rios, Rodrigo; Vuong, Cliff; Mehta, Mayank

All animals naturally perceive the abstract concept of space-time. A brain region called the Hippocampus is known to be important in creating these perceptions, but the underlying mechanisms are unknown. In our lab we employ several experimental and computational techniques from Physics to tackle this fundamental puzzle. Experimentally, we use ideas from Nanoscience and Materials Science to develop techniques to measure the activity of hippocampal neurons, in freely-behaving animals. Computationally, we develop models to study neuronal activity patterns, which are point processes that are highly stochastic and multidimensional. We then apply these techniques to collect and analyze neuronal signals from rodents while they're exploring space in Real World or Virtual Reality with various stimuli. Our findings show that under these conditions neuronal activity depends on various parameters, such as sensory cues including visual and auditory, and behavioral cues including, linear and angular, position and velocity. Further, neuronal networks create internally-generated rhythms, which influence perception of space and time. In totality, these results further our understanding of how the brain develops a cognitive map of our surrounding space, and keep track of time.

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

Wang, Y.; Tobias, B.; Chang, Y. -T.

Electron cyclotron emission (ECE) imaging is a passive radiometric technique that measures electron temperature fluctuations; and microwave imaging reflectometry (MIR) is an active radar imaging technique that measures electron density fluctuations. The microwave imaging diagnostic instruments employing these techniques have made important contributions to fusion science and have been adopted at major fusion facilities worldwide including DIII-D, EAST, ASDEX Upgrade, HL-2A, KSTAR, LHD, and J-TEXT. In this paper, we describe the development status of three major technological advancements: custom mm-wave integrated circuits (ICs), digital beamforming (DBF), and synthetic diagnostic modeling (SDM). These also have the potential to greatly advance microwavemore » fusion plasma imaging, enabling compact and low-noise transceiver systems with real-time, fast tracking ability to address critical fusion physics issues, including ELM suppression and disruptions in the ITER baseline scenario, naturally ELM-free states such as QH-mode, and energetic particle confinement (i.e. Alfven eigenmode stability) in high-performance regimes that include steady-state and advanced tokamak scenarios. Furthermore, these systems are fully compatible with today's most challenging non-inductive heating and current drive systems and capable of operating in harsh environments, making them the ideal approach for diagnosing long-pulse and steady-state tokamaks.« less

Transient excitation and mechanical admittance test techniques for prediction of payload vibration environments

NASA Technical Reports Server (NTRS)

Kana, D. D.; Vargas, L. M.

1977-01-01

Transient excitation forces were applied separately to simple beam-and-mass launch vehicle and payload models to develop complex admittance functions for the interface and other appropriate points on the structures. These measured admittances were then analytically combined by a matrix representation to obtain a description of the coupled system dynamic characteristics. Response of the payload model to excitation of the launch vehicle model was predicted and compared with results measured on the combined models. These results are also compared with results of earlier work in which a similar procedure was employed except that steady-state sinusoidal excitation techniques were included. It is found that the method employing transient tests produces results that are better overall than the steady state methods. Furthermore, the transient method requires far less time to implement, and provides far better resolution in the data. However, the data acquisition and handling problem is more complex for this method. It is concluded that the transient test and admittance matrix prediction method can be a valuable tool for development of payload vibration tests.

A Comprehensive Review on Water Quality Parameters Estimation Using Remote Sensing Techniques.

PubMed

Gholizadeh, Mohammad Haji; Melesse, Assefa M; Reddi, Lakshmi

2016-08-16

Remotely sensed data can reinforce the abilities of water resources researchers and decision makers to monitor waterbodies more effectively. Remote sensing techniques have been widely used to measure the qualitative parameters of waterbodies (i.e., suspended sediments, colored dissolved organic matter (CDOM), chlorophyll-a, and pollutants). A large number of different sensors on board various satellites and other platforms, such as airplanes, are currently used to measure the amount of radiation at different wavelengths reflected from the water's surface. In this review paper, various properties (spectral, spatial and temporal, etc.) of the more commonly employed spaceborne and airborne sensors are tabulated to be used as a sensor selection guide. Furthermore, this paper investigates the commonly used approaches and sensors employed in evaluating and quantifying the eleven water quality parameters. The parameters include: chlorophyll-a (chl-a), colored dissolved organic matters (CDOM), Secchi disk depth (SDD), turbidity, total suspended sediments (TSS), water temperature (WT), total phosphorus (TP), sea surface salinity (SSS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chemical oxygen demand (COD).

Query-based learning for aerospace applications.

PubMed

Saad, E W; Choi, J J; Vian, J L; Wunsch, D C Ii

2003-01-01

Models of real-world applications often include a large number of parameters with a wide dynamic range, which contributes to the difficulties of neural network training. Creating the training data set for such applications becomes costly, if not impossible. In order to overcome the challenge, one can employ an active learning technique known as query-based learning (QBL) to add performance-critical data to the training set during the learning phase, thereby efficiently improving the overall learning/generalization. The performance-critical data can be obtained using an inverse mapping called network inversion (discrete network inversion and continuous network inversion) followed by oracle query. This paper investigates the use of both inversion techniques for QBL learning, and introduces an original heuristic to select the inversion target values for continuous network inversion method. Efficiency and generalization was further enhanced by employing node decoupled extended Kalman filter (NDEKF) training and a causality index (CI) as a means to reduce the input search dimensionality. The benefits of the overall QBL approach are experimentally demonstrated in two aerospace applications: a classification problem with large input space and a control distribution problem.

A Comprehensive Review on Water Quality Parameters Estimation Using Remote Sensing Techniques

PubMed Central

Gholizadeh, Mohammad Haji; Melesse, Assefa M.; Reddi, Lakshmi

2016-01-01

Remotely sensed data can reinforce the abilities of water resources researchers and decision makers to monitor waterbodies more effectively. Remote sensing techniques have been widely used to measure the qualitative parameters of waterbodies (i.e., suspended sediments, colored dissolved organic matter (CDOM), chlorophyll-a, and pollutants). A large number of different sensors on board various satellites and other platforms, such as airplanes, are currently used to measure the amount of radiation at different wavelengths reflected from the water’s surface. In this review paper, various properties (spectral, spatial and temporal, etc.) of the more commonly employed spaceborne and airborne sensors are tabulated to be used as a sensor selection guide. Furthermore, this paper investigates the commonly used approaches and sensors employed in evaluating and quantifying the eleven water quality parameters. The parameters include: chlorophyll-a (chl-a), colored dissolved organic matters (CDOM), Secchi disk depth (SDD), turbidity, total suspended sediments (TSS), water temperature (WT), total phosphorus (TP), sea surface salinity (SSS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chemical oxygen demand (COD). PMID:27537896

Reliability of horizontal and vertical tube shift techniques in the localisation of supernumerary teeth.

PubMed

Mallineni, S K; Anthonappa, R P; King, N M

2016-12-01

To assess the reliability of the vertical tube shift technique (VTST) and horizontal tube shift technique (HTST) for the localisation of unerupted supernumerary teeth (ST) in the anterior region of the maxilla. A convenience sample of 83 patients who attended a major teaching hospital because of unerupted ST was selected. Only non-syndromic patients with ST and who had complete clinical and radiographic and surgical records were included in the study. Ten examiners independently rated the paired set of radiographs for each technique. Chi-square test, paired t test and kappa statistics were employed to assess the intra- and inter-examiner reliability. Paired sets of 1660 radiographs (830 pairs for each technique) were available for the analysis. The overall sensitivity for VTST and HTST was 80.6 and 72.1% respectively, with slight inter-examiner and good intra-examiner reliability. Statistically significant differences were evident between the two localisation techniques (p < 0.05). Localisation of unerupted ST using VTST was more successful than HTST in the anterior region of the maxilla.

Cross-calibration of Medium Resolution Earth Observing Satellites by Using EO-1 Hyperion-derived Spectral Surface Reflectance from "Lunar Cal Sites"

NASA Astrophysics Data System (ADS)

Ungar, S.

2017-12-01

Over the past 3 years, the Earth Observing-one (EO-1) Hyperion imaging spectrometer was used to slowly scan the lunar surface at a rate which results in up to 32X oversampling to effectively increase the SNR. Several strategies, including comparison against the USGS RObotic Lunar Observatory (ROLO) mode,l are being employed to estimate the absolute and relative accuracy of the measurement set. There is an existing need to resolve discrepancies as high as 10% between ROLO and solar based calibration of current NASA EOS assets. Although the EO-1 mission was decommissioned at the end of March 2017, the development of a well-characterized exoatmospheric spectral radiometric database, for a range of lunar phase angles surrounding the fully illuminated moon, continues. Initial studies include a comprehensive analysis of the existing 17-year collection of more than 200 monthly lunar acquisitions. Specific lunar surface areas, such as a lunar mare, are being characterized as potential "lunar calibration sites" in terms of their radiometric stability in the presence of lunar nutation and libration. Site specific Hyperion-derived lunar spectral reflectance are being compared against spectrographic measurements made during the Apollo program. Techniques developed through this activity can be employed by future high-quality orbiting imaging spectrometers (such as HyspIRI and EnMap) to further refine calibration accuracies. These techniques will enable the consistent cross calibration of existing and future earth observing systems (spectral and multi-spectral) including those that do not have lunar viewing capability. When direct lunar viewing is not an option for an earth observing asset, orbiting imaging spectrometers can serve as transfer radiometers relating that asset's sensor response to lunar values through near contemporaneous observations of well characterized stable CEOS test sites. Analysis of this dataset will lead to the development of strategies to ensure more accurate cross calibrations when employing the more capable, future imaging spectrometers.

Enhanced characterization of singly protonated phosphopeptide ions by femtosecond laser-induced ionization/dissociation tandem mass spectrometry (fs-LID-MS/MS).

PubMed

Smith, Scott A; Kalcic, Christine L; Safran, Kyle A; Stemmer, Paul M; Dantus, Marcos; Reid, Gavin E

2010-12-01

To develop an improved understanding of the regulatory role that post-translational modifications (PTMs) involving phosphorylation play in the maintenance of normal cellular function, tandem mass spectrometry (MS/MS) strategies coupled with ion activation techniques such as collision-induced dissociation (CID) and electron-transfer dissociation (ETD) are typically employed to identify the presence and site-specific locations of the phosphate moieties within a given phosphoprotein of interest. However, the ability of these techniques to obtain sufficient structural information for unambiguous phosphopeptide identification and characterization is highly dependent on the ion activation method employed and the properties of the precursor ion that is subjected to dissociation. Herein, we describe the application of a recently developed alternative ion activation technique for phosphopeptide analysis, termed femtosecond laser-induced ionization/dissociation (fs-LID). In contrast to CID and ETD, fs-LID is shown to be particularly suited to the analysis of singly protonated phosphopeptide ions, yielding a wide range of product ions including a, b, c, x, y, and z sequence ions, as well as ions that are potentially diagnostic of the positions of phosphorylation (e.g., 'a(n)+1-98'). Importantly, the lack of phosphate moiety losses or phosphate group 'scrambling' provides unambiguous information for sequence identification and phosphorylation site characterization. Therefore, fs-LID-MS/MS can serve as a complementary technique to established methodologies for phosphoproteomic analysis. Copyright © 2010. Published by Elsevier Inc.

Millimeter-wave signal generation for a wireless transmission system based on on-chip photonic integrated circuit structures.

PubMed

Guzmán, R; Carpintero, G; Gordon, C; Orbe, L

2016-10-15

We demonstrate and compare two different photonic-based signal sources for generating the carrier wave in a wireless communication link operating in the millimeter-wave range. The first signal source uses the optical heterodyne technique to generate a 113 GHz carrier wave frequency, while the second employs a different technique based on a pulsed mode-locked source with 100 GHz repetition rate frequency. The two optical sources were fabricated in a multi-project wafer run from an active/passive generic integration platform process using standardized building blocks, including multimode interference reflectors which allow us to define the structures on chip, without the need for cleaved facet mirrors. We highlight the superior performance of the mode-locked sources over an optical heterodyne technique. Error-free transmission was achieved in this experiment.

Calculating High Speed Centrifugal Compressor Performance from Averaged Measurements

NASA Astrophysics Data System (ADS)

Lou, Fangyuan; Fleming, Ryan; Key, Nicole L.

2012-12-01

To improve the understanding of high performance centrifugal compressors found in modern aircraft engines, the aerodynamics through these machines must be experimentally studied. To accurately capture the complex flow phenomena through these devices, research facilities that can accurately simulate these flows are necessary. One such facility has been recently developed, and it is used in this paper to explore the effects of averaging total pressure and total temperature measurements to calculate compressor performance. Different averaging techniques (including area averaging, mass averaging, and work averaging) have been applied to the data. Results show that there is a negligible difference in both the calculated total pressure ratio and efficiency for the different techniques employed. However, the uncertainty in the performance parameters calculated with the different averaging techniques is significantly different, with area averaging providing the least uncertainty.

High-speed three-dimensional shape measurement for dynamic scenes using bi-frequency tripolar pulse-width-modulation fringe projection

NASA Astrophysics Data System (ADS)

Zuo, Chao; Chen, Qian; Gu, Guohua; Feng, Shijie; Feng, Fangxiaoyu; Li, Rubin; Shen, Guochen

2013-08-01

This paper introduces a high-speed three-dimensional (3-D) shape measurement technique for dynamic scenes by using bi-frequency tripolar pulse-width-modulation (TPWM) fringe projection. Two wrapped phase maps with different wavelengths can be obtained simultaneously by our bi-frequency phase-shifting algorithm. Then the two phase maps are unwrapped using a simple look-up-table based number-theoretical approach. To guarantee the robustness of phase unwrapping as well as the high sinusoidality of projected patterns, TPWM technique is employed to generate ideal fringe patterns with slight defocus. We detailed our technique, including its principle, pattern design, and system setup. Several experiments on dynamic scenes were performed, verifying that our method can achieve a speed of 1250 frames per second for fast, dense, and accurate 3-D measurements.

A historical perspective with current opinion on the management of atrophic mandibular fractures.

PubMed

Castro-Núñez, Jaime; Cunningham, Larry L; Van Sickels, Joseph E

2017-12-01

The management of atrophic mandibular fractures has been a challenge for maxillofacial surgeons for decades. During the past 70 years, various techniques for treating edentulous mandibular fractures have been advocated. These techniques have been praised, criticized, abandoned, improved, and used in combination with other methods. Although some of the principles of management outlined before the end of World War II are still valid in today's technological era, other concepts did not survive the test of time. The aim of this paper is to examine the evolution of treatment modalities for the management of atrophic mandibular fractures that have been employed over the years. Debates and discussions generated by this topic are included. Current techniques and treatment philosophies with thoughts for future therapies are provided. Copyright © 2017 Elsevier Inc. All rights reserved.

Dietary Assessment on a Mobile Phone Using Image Processing and Pattern Recognition Techniques: Algorithm Design and System Prototyping

PubMed Central

Probst, Yasmine; Nguyen, Duc Thanh; Tran, Minh Khoi; Li, Wanqing

2015-01-01

Dietary assessment, while traditionally based on pen-and-paper, is rapidly moving towards automatic approaches. This study describes an Australian automatic food record method and its prototype for dietary assessment via the use of a mobile phone and techniques of image processing and pattern recognition. Common visual features including scale invariant feature transformation (SIFT), local binary patterns (LBP), and colour are used for describing food images. The popular bag-of-words (BoW) model is employed for recognizing the images taken by a mobile phone for dietary assessment. Technical details are provided together with discussions on the issues and future work. PMID:26225994

Monitoring estuarine circulation and ocean waste dispersion using an integrated satellite-aircraft-drogue approach. [Delaware coast and Delaware Bay

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Davis, G.; Wang, H.

1975-01-01

The author has identified the following significant results. An inexpensive, integrated drogue-aircraft-satellite approach was developed which is based on the Lagrangian technique and employs remotely tracked drogues and dyes together with satellite observation of natural tracers, such as suspended sediment. Results include current circulation studies in Delaware Bay in support of an oil slick movement model; investigations of the dispersion and movement of acid wastes dumped 40 miles off the Delaware coast; and coastal current circulation. In each case, the integrated drogue-aircraft-satellite approach compares favorably with other techniques on the basis of accuracy, cost effectiveness, and performance under severe weather conditions.

Development of a Transportable Gravity Gradiometer Based on Atom Interferometry

NASA Astrophysics Data System (ADS)

Yu, N.; Kohel, J. M.; Aveline, D. C.; Kellogg, J. R.; Thompson, R. J.; Maleki, L.

2007-12-01

JPL is developing a transportable gravity gradiometer based on light-pulse atom interferometers for NASA's Earth Science Technology Office's Instrument Incubator Program. The inertial sensors in this instrument employ a quantum interference measurement technique, analogous to the precise phase measurements in atomic clocks, which offers increased sensitivity and improved long-term stability over traditional mechanical devices. We report on the implementation of this technique in JPL's gravity gradiometer, and on the current performance of the mobile instrument. We also discuss the prospects for satellite-based gravity field mapping, including high-resolution monitoring of time-varying fields from a single satellite platform and multi-component measurements of the gravitational gradient tensor, using atom interferometer-based instruments.

Fixed gain and adaptive techniques for rotorcraft vibration control

NASA Technical Reports Server (NTRS)

Roy, R. H.; Saberi, H. A.; Walker, R. A.

1985-01-01

The results of an analysis effort performed to demonstrate the feasibility of employing approximate dynamical models and frequency shaped cost functional control law desgin techniques for helicopter vibration suppression are presented. Both fixed gain and adaptive control designs based on linear second order dynamical models were implemented in a detailed Rotor Systems Research Aircraft (RSRA) simulation to validate these active vibration suppression control laws. Approximate models of fuselage flexibility were included in the RSRA simulation in order to more accurately characterize the structural dynamics. The results for both the fixed gain and adaptive approaches are promising and provide a foundation for pursuing further validation in more extensive simulation studies and in wind tunnel and/or flight tests.

N-S/DSMC hybrid simulation of hypersonic flow over blunt body including wakes

NASA Astrophysics Data System (ADS)

Li, Zhonghua; Li, Zhihui; Li, Haiyan; Yang, Yanguang; Jiang, Xinyu

2014-12-01

A hybrid N-S/DSMC method is presented and applied to solve the three-dimensional hypersonic transitional flows by employing the MPC (modular Particle-Continuum) technique based on the N-S and the DSMC method. A sub-relax technique is adopted to deal with information transfer between the N-S and the DSMC. The hypersonic flows over a 70-deg spherically blunted cone under different Kn numbers are simulated using the CFD, DSMC and hybrid N-S/DSMC method. The present computations are found in good agreement with DSMC and experimental results. The present method provides an efficient way to predict the hypersonic aerodynamics in near-continuum transitional flow regime.

Control Law Design in a Computational Aeroelasticity Environment

NASA Technical Reports Server (NTRS)

Newsom, Jerry R.; Robertshaw, Harry H.; Kapania, Rakesh K.

2003-01-01

A methodology for designing active control laws in a computational aeroelasticity environment is given. The methodology involves employing a systems identification technique to develop an explicit state-space model for control law design from the output of a computational aeroelasticity code. The particular computational aeroelasticity code employed in this paper solves the transonic small disturbance aerodynamic equation using a time-accurate, finite-difference scheme. Linear structural dynamics equations are integrated simultaneously with the computational fluid dynamics equations to determine the time responses of the structure. These structural responses are employed as the input to a modern systems identification technique that determines the Markov parameters of an "equivalent linear system". The Eigensystem Realization Algorithm is then employed to develop an explicit state-space model of the equivalent linear system. The Linear Quadratic Guassian control law design technique is employed to design a control law. The computational aeroelasticity code is modified to accept control laws and perform closed-loop simulations. Flutter control of a rectangular wing model is chosen to demonstrate the methodology. Various cases are used to illustrate the usefulness of the methodology as the nonlinearity of the aeroelastic system is increased through increased angle-of-attack changes.

High-Energy Astrophysics: An Overview

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

2007-01-01

High-energy astrophysics is the study of objects and phenomena in space with energy densities much greater than that found in normal stars and galaxies. These include black holes, neutron stars, cosmic rays, hypernovae and gamma-ray bursts. A history and an overview of high-energy astrophysics will be presented, including a description of the objects that are observed. Observing techniques, space-borne missions in high-energy astrophysics and some recent discoveries will also be described. Several entirely new types of astronomy are being employed in high-energy astrophysics. These will be briefly described, along with some NASA missions currently under development.

Career satisfaction of Jordanian dental hygienists.

PubMed

Malkawi, Z A

2016-11-01

The aim of this study was to determine the factors that affect Jordanian dental hygienists with their career satisfaction including financial issues, employment settings and policies. Randomized sample of 102 dental hygienists with a bachelor's degree were selected from the entire population of Jordanian dental hygienists. Participants received a cover letter with a questionnaire. Findings were analysed using descriptive data techniques. Chi-square test was used to determine the statistically significant differences across demographic variables and career satisfaction's factors. About 22.5% of the participants are not working as dental hygienist. Dental hygiene profession in Jordan includes predominantly (74.0%) females. Majority of them (51.9%) were employed in JUST, and minority (6.3%) in MOH. Most of them (56.4%) were aged 24-29 years old, and mostly 62.2% with ≤1 child. About 53.1% employed by general dentist. Almost 35.3% had ≥4 years' job experience. Majority (47.6%) expressed high level of satisfaction with dental materials and equipment to practice work; however, only 2.0% expressed very high level of satisfaction with employment policies. Almost 32.4% expressed low level of satisfaction with salary level. Minority (2.0%) expressed dissatisfaction with quality of dentist's work. Statistically significant association was found between workplace, and dental materials and equipment to practice work, salary level, employment policies (P = 0.003, P = 0.003, P = 0.026), and number of children with flexibility in work hours (P = 0.001). Jordanian dental hygienists' workplacesatisfaction w as significantly associated with dental materials and equipment to practice work, salary level, and employment policies. Understanding the working patterns of dental hygienists in Jordan is important to increase their career satisfaction levels. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

System, Apparatus and Method Employing a Dual Head Laser

NASA Technical Reports Server (NTRS)

Coyle, Donald B. (Inventor); Stysley, Paul R. (Inventor); Poulios, Demetrios (Inventor)

2015-01-01

A system, apparatus and method employing a laser with a split-head, V-assembly gain material configuration. Additionally, the present invention is directed to techniques to better dissipate or remove unwanted energies in laser operations. The present invention is also directed to techniques for better collimated laser beams, with single spatial mode quality (TEM00), with improved efficiency, in extreme environments, such as in outer space.

In vivo evaluation of drug delivery after ultrasound application: A new use for the photoacoustic technique

NASA Astrophysics Data System (ADS)

Barja, P. R.; Acosta-Avalos, D.; Rompe, P. C. B.; Dos Anjos, F. H.; Marciano, F. R.; da Silva, M. D.

2005-06-01

Ultrasound application is a therapeutical resource widely employed in physiotherapy. One of its applications is the phonophoresis, a technique in which the ultrasound radiation is utilized to deliver drugs through the skin to soft tissues. The proposal of our study was to employ the Photoacoustic Technique to evaluate the efficacy of such treatment, analyzing if phonophoresis could enhance drug delivery through skin when compared to the more traditional method of manual massage. The configuration of the system employed was such that it was possible to perform in vivo measurements, which is a pre-requisite for this kind of study. The changes observed in the photoacoustic signal amplitude after each form of drug application were attributed to changes in the thermal effusivity of the system, due to penetration of the drug. The technique was able to detect differences in drug delivery between the specified physiotherapy treatments, indicating that phonophoresis enhances drug absorption by tissue.

Monitoring beach changes using GPS surveying techniques

USGS Publications Warehouse

Morton, Robert; Leach, Mark P.; Paine, Jeffrey G.; Cardoza, Michael A.

1993-01-01

The adaptation of Global Positioning System (GPS) surveying techniques to beach monitoring activities is a promising response to this challenge. An experiment that employed both GPS and conventional beach surveying was conducted, and a new beach monitoring method employing kinematic GPS surveys was devised. This new method involves the collection of precise shore-parallel and shore-normal GPS positions from a moving vehicle so that an accurate two-dimensional beach surface can be generated. Results show that the GPS measurements agree with conventional shore-normal surveys at the 1 cm level, and repeated GPS measurements employing the moving vehicle demonstrate a precision of better than 1 cm. In addition, the nearly continuous sampling and increased resolution provided by the GPS surveying technique reveals alongshore changes in beach morphology that are undetected by conventional shore-normal profiles. The application of GPS surveying techniques combined with the refinement of appropriate methods for data collection and analysis provides a better understanding of beach changes, sediment transport, and storm impacts.

Optimization of Insertion Cost for Transfer Trajectories to Libration Point Orbits

NASA Technical Reports Server (NTRS)

Howell, K. C.; Wilson, R. S.; Lo, M. W.

1999-01-01

The objective of this work is the development of efficient techniques to optimize the cost associated with transfer trajectories to libration point orbits in the Sun-Earth-Moon four body problem, that may include lunar gravity assists. Initially, dynamical systems theory is used to determine invariant manifolds associated with the desired libration point orbit. These manifolds are employed to produce an initial approximation to the transfer trajectory. Specific trajectory requirements such as, transfer injection constraints, inclusion of phasing loops, and targeting of a specified state on the manifold are then incorporated into the design of the transfer trajectory. A two level differential corrections process is used to produce a fully continuous trajectory that satisfies the design constraints, and includes appropriate lunar and solar gravitational models. Based on this methodology, and using the manifold structure from dynamical systems theory, a technique is presented to optimize the cost associated with insertion onto a specified libration point orbit.

Radiative transfer equation accounting for rotational Raman scattering and its solution by the discrete-ordinates method

NASA Astrophysics Data System (ADS)

Rozanov, Vladimir V.; Vountas, Marco

2014-01-01

Rotational Raman scattering of solar light in Earth's atmosphere leads to the filling-in of Fraunhofer and telluric lines observed in the reflected spectrum. The phenomenological derivation of the inelastic radiative transfer equation including rotational Raman scattering is presented. The different forms of the approximate radiative transfer equation with first-order rotational Raman scattering terms are obtained employing the Cabannes, Rayleigh, and Cabannes-Rayleigh scattering models. The solution of these equations is considered in the framework of the discrete-ordinates method using rigorous and approximate approaches to derive particular integrals. An alternative forward-adjoint technique is suggested as well. A detailed description of the model including the exact spectral matching and a binning scheme that significantly speeds up the calculations is given. The considered solution techniques are implemented in the radiative transfer software package SCIATRAN and a specified benchmark setup is presented to enable readers to compare with own results transparently.

In vivo quantification of spatially-varying mechanical properties in developing tissues

PubMed Central

Serwane, Friedhelm; Mongera, Alessandro; Rowghanian, Payam; Kealhofer, David A.; Lucio, Adam A.; Hockenbery, Zachary M.; Campàs, Otger

2017-01-01

It is generally believed that the mechanical properties of the cellular microenvironment and their spatiotemporal variations play a central role in sculpting embryonic tissues, maintaining organ architecture and controlling cell behavior, including cell differentiation. However, no direct in vivo and in situ measurement of mechanical properties within developing 3D tissues and organs has been performed yet. Here we introduce a technique that employs biocompatible ferrofluid microdroplets as local mechanical actuators and allows quantitative spatiotemporal measurements of mechanical properties in vivo. Using this technique, we show that vertebrate body elongation entails spatially-varying tissue mechanics along the anteroposterior axis. Specifically, we find that the zebrafish tailbud is viscoelastic (elastic below a few seconds and fluid after just one minute) and displays decreasing stiffness and increasing fluidity towards its posterior elongating region. This method opens new avenues to study mechanobiology in vivo, both in embryogenesis and in disease processes, including cancer. PMID:27918540

CMOS imager for pointing and tracking applications

NASA Technical Reports Server (NTRS)

Sun, Chao (Inventor); Pain, Bedabrata (Inventor); Yang, Guang (Inventor); Heynssens, Julie B. (Inventor)

2006-01-01

Systems and techniques to realize pointing and tracking applications with CMOS imaging devices. In general, in one implementation, the technique includes: sampling multiple rows and multiple columns of an active pixel sensor array into a memory array (e.g., an on-chip memory array), and reading out the multiple rows and multiple columns sampled in the memory array to provide image data with reduced motion artifact. Various operation modes may be provided, including TDS, CDS, CQS, a tracking mode to read out multiple windows, and/or a mode employing a sample-first-read-later readout scheme. The tracking mode can take advantage of a diagonal switch array. The diagonal switch array, the active pixel sensor array and the memory array can be integrated onto a single imager chip with a controller. This imager device can be part of a larger imaging system for both space-based applications and terrestrial applications.

Road following for blindBike: an assistive bike navigation system for low vision persons

NASA Astrophysics Data System (ADS)

Grewe, Lynne; Overell, William

2017-05-01

Road Following is a critical component of blindBike, our assistive biking application for the visually impaired. This paper talks about the overall blindBike system and goals prominently featuring Road Following, which is the task of directing the user to follow the right side of the road. This work unlike what is commonly found for self-driving cars does not depend on lane line markings. 2D computer vision techniques are explored to solve the problem of Road Following. Statistical techniques including the use of Gaussian Mixture Models are employed. blindBike is developed as an Android Application and is running on a smartphone device. Other sensors including Gyroscope and GPS are utilized. Both Urban and suburban scenarios are tested and results are given. The success and challenges faced by blindBike's Road Following module are presented along with future avenues of work.

Development of optical monitor of alpha radiations based on CR-39.

PubMed

Joshirao, Pranav M; Shin, Jae Won; Vyas, Chirag K; Kulkarni, Atul D; Kim, Hojoong; Kim, Taesung; Hong, Seung-Woo; Manchanda, Vijay K

2013-11-01

Fukushima accident has highlighted the need to intensify efforts to develop sensitive detectors to monitor the release of alpha emitting radionuclides in the environment caused by the meltdown of the discharged spent fuel. Conventionally, proportional counting, scintillation counting and alpha spectrometry are employed to assay the alpha emitting radionuclides but these techniques are difficult to be configured for online operations. Solid State Nuclear Track Detectors (SSNTDs) offer an alternative off line sensitive technique to measure alpha emitters as well as fissile radionuclides at ultra-trace level in the environment. Recently, our group has reported the first ever attempt to use reflectance based fiber optic sensor (FOS) to quantify the alpha radiations emitted from (232)Th. In the present work, an effort has been made to develop an online FOS to monitor alpha radiations emitted from (241)Am source employing CR-39 as detector. Here, we report the optical response of CR-39 (on exposure to alpha radiations) employing techniques such as Atomic Force Microscopy (AFM) and Reflectance Spectroscopy. In the present work GEANT4 simulation of transport of alpha particles in the detector has also been carried out. Simulation includes validation test wherein the projected ranges of alpha particles in the air, polystyrene and CR-39 were calculated and were found to agree with the literature values. An attempt has been further made to compute the fluence as a function of the incidence angle and incidence energy of alphas. There was an excellent correlation in experimentally observed track density with the simulated fluence. The present work offers a novel approach to design an online CR-39 based fiber optic sensor (CRFOS) to measure the release of nanogram quantity of (241)Am in the environment. © 2013 Elsevier Ltd. All rights reserved.

Solid-state energy storage module employing integrated interconnect board

DOEpatents

Rouillard, Jean; Comte, Christophe; Daigle, Dominik; Hagen, Ronald A.; Knudson, Orlin B.; Morin, Andre; Ranger, Michel; Ross, Guy; Rouillard, Roger; St-Germain, Philippe; Sudano, Anthony; Turgeon, Thomas A.

2000-01-01

The present invention is directed to an improved electrochemical energy storage device. The electrochemical energy storage device includes a number of solid-state, thin-film electrochemical cells which are selectively interconnected in series or parallel through use of an integrated interconnect board. The interconnect board is typically disposed within a sealed housing which also houses the electrochemical cells, and includes a first contact and a second contact respectively coupled to first and second power terminals of the energy storage device. The interconnect board advantageously provides for selective series or parallel connectivity with the electrochemical cells, irrespective of electrochemical cell position within the housing. In one embodiment, a sheet of conductive material is processed by employing a known milling, stamping, or chemical etching technique to include a connection pattern which provides for flexible and selective interconnecting of individual electrochemical cells within the housing, which may be a hermetically sealed housing. Fuses and various electrical and electro-mechanical devices, such as bypass, equalization, and communication devices for example, may also be mounted to the interconnect board and selectively connected to the electrochemical cells.

Lithium D-cell study

NASA Technical Reports Server (NTRS)

Size, P.; Takeuchi, Esther S.

1993-01-01

The purpose of this contract is to evaluate parametrically the effects of various factors including the electrolyte type, electrolyte concentration, depolarizer type, and cell configuration on lithium cell electrical performance and safety. This effort shall allow for the selection and optimization of cell design for future NASA applications while maintaining close ties with WGL's continuous improvements in manufacturing processes and lithium cell design. Taguchi experimental design techniques are employed in this task, and allow for a maximum amount of information to be obtained while requiring significantly less cells than if a full factorial design were employed. Acceptance testing for this task is modeled after the NASA Document EP5-83-025, Revision C, for cell weights, OCV's and load voltages. The performance attributes that are studied in this effort are fresh capacity and start-up characteristics evaluated at two rates and two temperatures, shelf-life characteristics including start-up and capacity retention, and iterative microcalorimetry measurements. Abuse testing includes forced over discharge at two rates with and without diode protection, temperature tolerance testing, and shorting tests at three rates with the measurement of heat generated during shorting conditions.

Bioreactor technology for production of valuable algal products

NASA Astrophysics Data System (ADS)

Liu, Guo-Cai; Cao, Ying

1998-03-01

Bioreactor technology has long been employed for the production of various (mostly cheap) food and pharmaceutical products. More recently, research has been mainly focused on the development of novel bioreactor technology for the production of high—value products. This paper reports the employment of novel bioreactor technology for the production of high-value biomass and metabolites by microalgae. These high-value products include microalgal biomass as health foods, pigments including phycocyanin and carotenoids, and polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid. The processes involved include heterotrophic and mixotrophic cultures using organic substrates as the carbon source. We have demonstrated that these bioreactor cultivation systems are particularly suitable for the production of high-value products from various microalgae. These cultivation systems can be further modified to improve cell densities and productivities by using high cell density techniques such as fed-batch and membrane cell recycle systems. For most of the microalgae investigated, the maximum cell concentrations obtained using these bioreactor systems in our laboratories are much higher than any so far reported in the literature.

Uncertainty assessment of PM2.5 contamination mapping using spatiotemporal sequential indicator simulations and multi-temporal monitoring data.

PubMed

Yang, Yong; Christakos, George; Huang, Wei; Lin, Chengda; Fu, Peihong; Mei, Yang

2016-04-12

Because of the rapid economic growth in China, many regions are subjected to severe particulate matter pollution. Thus, improving the methods of determining the spatiotemporal distribution and uncertainty of air pollution can provide considerable benefits when developing risk assessments and environmental policies. The uncertainty assessment methods currently in use include the sequential indicator simulation (SIS) and indicator kriging techniques. However, these methods cannot be employed to assess multi-temporal data. In this work, a spatiotemporal sequential indicator simulation (STSIS) based on a non-separable spatiotemporal semivariogram model was used to assimilate multi-temporal data in the mapping and uncertainty assessment of PM2.5 distributions in a contaminated atmosphere. PM2.5 concentrations recorded throughout 2014 in Shandong Province, China were used as the experimental dataset. Based on the number of STSIS procedures, we assessed various types of mapping uncertainties, including single-location uncertainties over one day and multiple days and multi-location uncertainties over one day and multiple days. A comparison of the STSIS technique with the SIS technique indicate that a better performance was obtained with the STSIS method.

Uncertainty assessment of PM2.5 contamination mapping using spatiotemporal sequential indicator simulations and multi-temporal monitoring data

NASA Astrophysics Data System (ADS)

Yang, Yong; Christakos, George; Huang, Wei; Lin, Chengda; Fu, Peihong; Mei, Yang

2016-04-01

Because of the rapid economic growth in China, many regions are subjected to severe particulate matter pollution. Thus, improving the methods of determining the spatiotemporal distribution and uncertainty of air pollution can provide considerable benefits when developing risk assessments and environmental policies. The uncertainty assessment methods currently in use include the sequential indicator simulation (SIS) and indicator kriging techniques. However, these methods cannot be employed to assess multi-temporal data. In this work, a spatiotemporal sequential indicator simulation (STSIS) based on a non-separable spatiotemporal semivariogram model was used to assimilate multi-temporal data in the mapping and uncertainty assessment of PM2.5 distributions in a contaminated atmosphere. PM2.5 concentrations recorded throughout 2014 in Shandong Province, China were used as the experimental dataset. Based on the number of STSIS procedures, we assessed various types of mapping uncertainties, including single-location uncertainties over one day and multiple days and multi-location uncertainties over one day and multiple days. A comparison of the STSIS technique with the SIS technique indicate that a better performance was obtained with the STSIS method.

Surgical management of pain.

PubMed

Goodman, R R

1990-07-01

This article presents an overview of the neuroanatomical, neurochemical, and neurophysiological substrates of nociception relevant to the neurosurgical treatment of chronic pain. Consideration is given to the various procedures currently employed in the treatment of patients suffering from medically intractable chronic pain of both benign and malignant diseases, including their indications, techniques, and results. Particular attention is given to the modern neuroaugmentative methods, such as electrical stimulation and CNS drug infusion, that are progressively overshadowing the previously developed ablative procedures.

Guidelines for Setting Up an Extended Field Trip to Florida and the Florida Keys: An Interactive Experiential Training Field Biology Program Consisting of Pretrip Instruction, Search Image Training, Field Exercises, and Observations of Tropical Habitats and Coral Reefs.

ERIC Educational Resources Information Center

Baker, Claude D.; And Others

The importance of experiential aspects of biological study is addressed using multi-dimensional classroom and field classroom approaches to student learning. This document includes a guide to setting up this style of field experience. Several teaching innovations are employed to introduce undergraduate students to the literature, techniques, and…

Parallel Visualization Co-Processing of Overnight CFD Propulsion Applications

NASA Technical Reports Server (NTRS)

Edwards, David E.; Haimes, Robert

1999-01-01

An interactive visualization system pV3 is being developed for the investigation of advanced computational methodologies employing visualization and parallel processing for the extraction of information contained in large-scale transient engineering simulations. Visual techniques for extracting information from the data in terms of cutting planes, iso-surfaces, particle tracing and vector fields are included in this system. This paper discusses improvements to the pV3 system developed under NASA's Affordable High Performance Computing project.

Asia-Pacific working group consensus on non-variceal upper gastrointestinal bleeding: an update 2018.

PubMed

Sung, Joseph Jy; Chiu, Philip Cy; Chan, Francis K L; Lau, James Yw; Goh, Khean-Lee; Ho, Lawrence Hy; Jung, Hwoon-Young; Sollano, Jose D; Gotoda, Takuji; Reddy, Nageshwar; Singh, Rajvinder; Sugano, Kentaro; Wu, Kai-Chun; Wu, Chun-Yin; Bjorkman, David J; Jensen, Dennis M; Kuipers, Ernst J; Lanas, Angel

2018-04-24

Non-variceal upper gastrointestinal bleeding remains an important emergency condition, leading to significant morbidity and mortality. As endoscopic therapy is the 'gold standard' of management, treatment of these patients can be considered in three stages: pre-endoscopic treatment, endoscopic haemostasis and post-endoscopic management. Since publication of the Asia-Pacific consensus on non-variceal upper gastrointestinal bleeding (NVUGIB) 7 years ago, there have been significant advancements in the clinical management of patients in all three stages. These include pre-endoscopy risk stratification scores, blood and platelet transfusion, use of proton pump inhibitors; during endoscopy new haemostasis techniques (haemostatic powder spray and over-the-scope clips); and post-endoscopy management by second-look endoscopy and medication strategies. Emerging techniques, including capsule endoscopy and Doppler endoscopic probe in assessing adequacy of endoscopic therapy, and the pre-emptive use of angiographic embolisation, are attracting new attention. An emerging problem is the increasing use of dual antiplatelet agents and direct oral anticoagulants in patients with cardiac and cerebrovascular diseases. Guidelines on the discontinuation and then resumption of these agents in patients presenting with NVUGIB are very much needed. The Asia-Pacific Working Group examined recent evidence and recommends practical management guidelines in this updated consensus statement. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effects of spaceflight in the adductor longus muscle of rats flown in the Soviet Biosatellite COSMOS 2044. A study employing neural cell adhesion molecule (N-CAM) immunocytochemistry and conventional morphological techniques (light and electron microscopy)

NASA Technical Reports Server (NTRS)

D'Amelio, F.; Daunton, N. G.

1992-01-01

The effects of spaceflight upon the "slow" muscle adductor longus were examined in rats flown in the Soviet Biosatellite COSMOS 2044. The techniques employed included standard methods for light microscopy, neural cell adhesion molecule (N-CAM) immunocytochemistry and electron microscopy. Light microscopic observations revealed myofiber atrophy and segmental necrosis accompanied by cellular infiltrates composed of macrophages, leukocytes and mononuclear cells. Neural cell adhesion molecule immunoreactivity (N-CAM-IR) was seen on the myofiber surface and in regenerating myofibers. Ultrastructural alterations included Z band streaming, disorganization of myofibrillar architecture, sarcoplasmic degradation, extensive segmental necrosis with apparent preservation of the basement membrane, degenerative phenomena of the capillary endothelium and cellular invasion of necrotic areas. Regenerating myofibers were identified by the presence of increased amounts of ribosomal aggregates and chains of polyribosomes associated with myofilaments. The principal electron microscopic changes of the neuromuscular junctions showed axon terminals with a decrease or absence of synaptic vesicles replaced by microtubules and neurofilaments, degeneration of axon terminals, vacant axonal spaces and changes suggestive of axonal sprouting. The present observations suggest that alterations such as myofibrillar disruption and necrosis, muscle regeneration and denervation and synaptic remodeling at the level of the neuromuscular junction may take place during spaceflight.

Different Applications of FORTRACC: From Convective Clouds to thunderstorms and radar fields

NASA Astrophysics Data System (ADS)

Morales, C.; Machado, L. A.

2009-09-01

The algorithm Forecasting and Tracking the Evolution of Cloud Clusters (ForTraCC), Vila et al. (2008), has been employed operationally in Brazil since 2005 to track and forecast the development of convective clouds. This technique depicts the main morphological features of the cloud systems and most importantly it reconstructs its entire life cycle. Based on this information, several relationships that use the area expansion and convective and stratiform fraction are employed to predict the life time duration and cloud area. Because of these features, the civil defense and power companies are using this information to mitigate the damages in the population. Further developments in FORTRACC included the integration of satellite rainfall retrievals, radar fields and thunderstorm initiation. These improvements try to address the following problems: a) most of the satellite rainfall retrievals do not take into account the life cycle stage that it is a key element on defining the rain area and rain intensity; b) by using the life cycle information it is possible to better predict the precipitation pattern observed in the radar fields; c) cloud signatures are associated to the development of systems that have lightning and no lightning activity. During the presentation, an overview of the different applications of FORTRACC will be presented including case studies and evaluation of the technique. Finally, the presentation will address how the users can have access to the algorithm to implement in their institute.

75 FR 39621 - Proposed Information Collection (Income-Net Worth and Employment Statement) Activity: Comment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-09

... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-0002] Proposed Information Collection (Income-Net Worth and Employment Statement) Activity: Comment Request AGENCY: Veterans Benefits Administration... techniques or the use of other forms of information technology. Title: Income-Net Worth and Employment...

Ionization techniques in capillary electrophoresis-mass spectrometry: principles, design, and application.

PubMed

Hommerson, Paul; Khan, Amjad M; de Jong, Gerhardus J; Somsen, Govert W

2011-01-01

A major step forward in the development and application of capillary electrophoresis (CE) was its coupling to ESI-MS, first reported in 1987. More than two decades later, ESI has remained the principal ionization technique in CE-MS, but a number of other ionization techniques have also been implemented. In this review the state-of-the-art in the employment of soft ionization techniques for CE-MS is presented. First the fundamentals and general challenges of hyphenating conventional CE and microchip electrophoresis with MS are outlined. After elaborating on the characteristics and role of ESI, emphasis is put on alternative ionization techniques including sonic spray ionization (SSI), thermospray ionization (TSI), atmospheric pressure chemical ionization (APCI), atmospheric pressure photoionization (APPI), matrix-assisted laser desorption ionization (MALDI) and continuous-flow fast atom bombardment (CF-FAB). The principle of each ionization technique is outlined and the experimental set-ups of the CE-MS couplings are described. The strengths and limitations of each ionization technique with respect to CE-MS are discussed and the applicability of the various systems is illustrated by a number of typical examples. Copyright © 2011 Wiley Periodicals, Inc.

A matrix equation solution by an optimization technique

NASA Technical Reports Server (NTRS)

Johnson, M. J.; Mittra, R.

1972-01-01

The computer solution of matrix equations is often difficult to accomplish due to an ill-conditioned matrix or high noise levels. Two methods of solution are compared for matrices of various degrees of ill-conditioning and for various noise levels in the right hand side vector. One method employs the usual Gaussian elimination. The other solves the equation by an optimization technique and employs a function minimization subroutine.

Engineering of Multifunctional Nanomaterials for Cancer Theranostics

NASA Astrophysics Data System (ADS)

Goel, Shreya

Development of novel imaging probes for cancer diagnosis is critical for early disease detection and management. The past two decades have witnessed a surge in the development and evolution of radiolabeled nanoparticles as a new frontier in personalized cancer nanomedicine. The dynamic synergism of positron emission tomography (PET) and nanotechnology combines the sensitivity and quantitative nature of PET with the multifunctionality and tunability of nanomaterials, which can help overcome certain key challenges in the field. Silica, "generally recognized as safe" (GRAS) by the Food and Drug Administration (FDA) of the United States, has emerged as one of the leading nanomaterials employed for molecular imaging and therapy of a wide variety of diseases, including cancer. However in vivo biodistribution and active targeting of silica-based nanomaterials has remained a relatively under explored area, based mainly on semi-quantitative techniques such as fluorescence imaging. In this dissertation, I explore the concept of radiolabeled silica nanoparticles for vasculature-targeted imaging of different tumor types. Both chelator-based and chelator-free radiolabeling techniques were employed for accurate and quantitative analysis of the in vivo pharmacokinetics of radiolabeled silica nanomaterials. (Chapters 2 and 3) The large surface area, ease of tunability and facile silica chemistry were employed to create multifunctional silica-based materials to simultaneously seek-and-treat cancers, by incorporating multiple components into a single nanoplatform. Photodynamic agent, porphyrin was loaded into the central cavity of hollow mesoporous silica nanoparticles, and the shell was decorated with photothermal nanoparticles, CuS, yielding a multimodal theranostic nanoplatform which could synergistically annihilate the tumor without relapse. (Chapter 4). A major hurdle in the successful clinical translation of nanomaterials is their rapid sequestration by the organs of the reticuloendothelial system (RES), mainly liver and spleen, and prolonged retention in the body, raising long-term toxicity concerns. To combat this issue, two approaches were employed; (i) Synthesis of biodegradable mesoporous silica nanoparticles (Chapter 5), and (ii) development of ultrasmall nanoparticles including renal clearable Au nanoparticles and hepatically cleared ultrasmall mesoporous silica nanoparticles (Chapter 6); for prolonged blood circulation, enhanced tumor uptake and rapid clearance from the body, enabling unprecedented tumor-to-normal tissue contrast. Overall, the reported studies explore the synergism of molecular imaging and therapy, and nanotechnology. While the application of nanomaterials in the former imparts multifunctionality to the molecular agent, allowing multimodal imaging and synergistic therapeutic regimes to be carried out simultaneously; molecular imaging techniques such as PET, allow accurate measurement of the in vivo pharmacokinetics of the nanomaterials, playing a major role towards their successful clinical translation. Further work will be required to better understand the in vivo biodistribution of both biodegradable and ultrasmall nanomaterials, and further employ them for early and specific detection of cancer, effective treatment and monitoring.

An Evaluation of GuttaFlow2 in Filling Artificial Internal Resorption Cavities: An in vitro Study.

PubMed

Mohammad, Yara; Alafif, Hisham; Hajeer, Mohammad; Yassin, Oula

2016-06-01

Obturation of root canal with internal resorption represents a major challenge in Endodontics. In spite of that, usual obturation techniques are often employed without considering the best technique to solve this problem. The goal of this study was to investigate the ability of GuttaFlow2 in filling artificial internal resorption cavities. The study sample included 36 human upper central incisors that were prepared using Protaper system (F4). Internal resorption cavities were prepared by cutting each tooth at 7 mm from the apex and preparing hemispherical cavities on both the sides and then re-attaching them. The sample was randomly separated into three groups (n = 12 in each group). In the first group, thermal injection technique (Obtura II) was employed and served as the control group. In the second group, injection of cold free-flow obturation technique with a master cone (GF2-C) was employed, whereas in the third group injection of cold free-flow obturation without a master cone (GF2) was followed. The teeth were re-cut at the same level as before and examined under a stereomicroscope. Subsequently, the captured images were transferred to AutoCAD program to measure the percentage of total filling "TF," gutta-percha "G," sealer "S," and voids "V" out of the total surface of the cross sections. All materials showed high filling properties in terms of "total filling," ranging from 99.17% (for Obtura II) to 99.72% (for GF2-C). Regarding gutta-percha percentages of filling, they ranged from 83.15 to 83.93%, whereas those for the sealer ranged from 5.71 to 15.24%. GuttaFlow2 group with a master cone appeared to give the best results despite the insignificant differences among the three groups. The GuttaFlow2 with a master cone technique seemed to be a promising filling material and gave results similar to those observed with Obtura II. It is recommended for use to obturate internal resorption cavities in clinical practice due to its good adaptability to root canal walls, ease of handling, and application. Internal resorption defects can be successfully filled with GuttaFlow2 material when supplemented with a master cone, and the results are comparable with those obtained with the Obtura II technique.

A discussion of current issues and concepts in the practice of skull-photo/craniofacial superimposition.

PubMed

Gordon, G M; Steyn, M

2016-05-01

A recent review paper on cranio-facial superimposition (CFS) stated that "there have been specific conceptual variances" from the original methods used in the practice of skull-photo superimposition, leading to poor results as far as accuracy is concerned. It was argued that the deviations in the practice of the technique have resulted in the reduced accuracies (for both failure to include and failure to exclude) that are noted in several recent studies. This paper aims to present the results from recent research to highlight the advancement of skull-photo/cranio-facial superimposition, and to discuss some of the issues raised regarding deviations from original techniques. The evolving methodology of CFS is clarified in context with the advancement of technology, forensic science and specifically within the field of forensic anthropology. Developments in the skull-photo/cranio-facial superimposition techniques have largely focused on testing reliability and accuracy objectively. Techniques now being employed by forensic anthropologists must conform to rigorous scientific testing and methodologies. Skull-photo/cranio-facial superimposition is constantly undergoing accuracy and repeatability testing which is in line with the principles of the scientific method and additionally allows for advancement in the field. Much of the research has indicated that CFS is useful in exclusion which is consistent with the concept of Popperian falsifiability - a hypothesis and experimental design which is falsifiable. As the hypothesis is disproved or falsified, another evolves to replace it and explain the new observations. Current and future studies employing different methods to test the accuracy and reliability of skull-photo/cranio-facial superimposition will enable researchers to establish the contribution the technique can have for identification purposes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Why is recruitment to trials difficult? An investigation into recruitment difficulties in an RCT of supported employment in patients with severe mental illness

PubMed Central

Howard, Louise; de Salis, Isabel; Tomlin, Zelda; Thornicroft, Graham; Donovan, Jenny

2009-01-01

Background Under-recruitment to randomised controlled trials (RCTs) is often problematic and there may be particular difficulties in recruiting patients with severe mental illness. Aim To evaluate reasons for under-recruitment in an RCT of patients with severe mental illness Methods Qualitative study during the recruitment phase of an RCT of supported employment. Trial staff and recruiting clinicians were interviewed. Data were analyzed thematically using constant comparative techniques. Results Recruitment rates were low. Five main reasons for recruitment difficulties were found. These included: (i) misconceptions about trials, (ii) lack of equipoise, (iii) misunderstanding of the trial arms, (iv) variable interpretations of eligibility criteria, (v) paternalism. Conclusion Reasons for recruitment difficulties in trials involving patients with severe mental illness include issues that occur in trials in general, but others are more specific to these patients. Clinician and patient involvement in the study design may improve recruitment in future similar trials. PMID:18718555

A new robust control scheme using second order sliding mode and fuzzy logic of a DFIM supplied by two five-level SVPWM inverters

NASA Astrophysics Data System (ADS)

Boudjema, Zinelaabidine; Taleb, Rachid; Bounadja, Elhadj

2017-02-01

Traditional filed oriented control strategy including proportional-integral (PI) regulator for the speed drive of the doubly fed induction motor (DFIM) have some drawbacks such as parameter tuning complications, mediocre dynamic performances and reduced robustness. Therefore, based on the analysis of the mathematical model of a DFIM supplied by two five-level SVPWM inverters, this paper proposes a new robust control scheme based on super twisting sliding mode and fuzzy logic. The conventional sliding mode control (SMC) has vast chattering effect on the electromagnetic torque developed by the DFIM. In order to resolve this problem, a second order sliding mode technique based on super twisting algorithm and fuzzy logic functions is employed. The validity of the employed approach was tested by using Matlab/Simulink software. Interesting simulation results were obtained and remarkable advantages of the proposed control scheme were exposed including simple design of the control system, reduced chattering as well as the other advantages.

Base drive and overlap protection circuit

DOEpatents

Gritter, David J.

1983-01-01

An inverter (34) which provides power to an A. C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A. C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A. C. machine is optimized. The control circuit includes a microcomputer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). A base drive and overlap protection circuit is included to insure that both transistors of a complimentary pair are not conducting at the same time. In its preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack (32) and a three-phase induction motor (18).

Encapsulation in the food industry: a review.

PubMed

Gibbs, B F; Kermasha, S; Alli, I; Mulligan, C N

1999-05-01

Encapsulation involves the incorporation of food ingredients, enzymes, cells or other materials in small capsules. Applications for this technique have increased in the food industry since the encapsulated materials can be protected from moisture, heat or other extreme conditions, thus enhancing their stability and maintaining viability. Encapsulation in foods is also utilized to mask odours or tastes. Various techniques are employed to form the capsules, including spray drying, spray chilling or spray cooling, extrusion coating, fluidized bed coating, liposome entrapment, coacervation, inclusion complexation, centrifugal extrusion and rotational suspension separation. Each of these techniques is discussed in this review. A wide variety of foods is encapsulated--flavouring agents, acids bases, artificial sweeteners, colourants, preservatives, leavening agents, antioxidants, agents with undesirable flavours, odours and nutrients, among others. The use of encapsulation for sweeteners such as aspartame and flavours in chewing gum is well known. Fats, starches, dextrins, alginates, protein and lipid materials can be employed as encapsulating materials. Various methods exist to release the ingredients from the capsules. Release can be site-specific, stage-specific or signalled by changes in pH, temperature, irradiation or osmotic shock. In the food industry, the most common method is by solvent-activated release. The addition of water to dry beverages or cake mixes is an example. Liposomes have been applied in cheese-making, and its use in the preparation of food emulsions such as spreads, margarine and mayonnaise is a developing area. Most recent developments include the encapsulation of foods in the areas of controlled release, carrier materials, preparation methods and sweetener immobilization. New markets are being developed and current research is underway to reduce the high production costs and lack of food-grade materials.

Association between HIV status and depressive symptoms among children and adolescents in the Southern Highlands Zone, Tanzania: A case-control study.

PubMed

Lwidiko, Abraham; Kibusi, Stephen Matthew; Nyundo, Azan; Mpondo, Bonaventura C T

2018-01-01

Children and adolescents continue to have HIV/AIDS in southern Saharan Africa. Scaling up of HIV services has significantly improved access to ARV and consequently improved on morbidity and mortality related to HIV/AIDS including opportunistic infection. Despite the above efforts, non-communicable conditions including mental disorders such as depression have been observed to contribute to the burden of disabilities about which little is documented. This study, therefore, aimed to determine the magnitude of depressive symptoms and the associated factors among HIV-infected children and adolescents. The study was a matched case-control design involving 300 cases of HIV-infected children matched by age and sex against 600 uninfected controls. Systematic sampling technique was used to select the cases while multistage sampling technique was employed to identify villages/ streets purposive and sampling technique was employed to obtain participants from households. The overall prevalence of depressive symptoms among the cohort of 900 participants was found to be 12.9%, with 27% of HIV-infected and 5.8% of HIV-uninfected children and adolescents screened positive for depressive symptoms. Multiple logistic regression revealed that being HIV-infected (AOR 1.96(1.11-3.45)), residing in a rural setting (AOR 0.61(0.39-0.96)) and history of childhood deprivation (AOR 4.76 (2.79-8.13)) were significantly associated with depressive symptoms. HIV infected adolescents are more affected by depression compared to non-infected counterparts. Childhood deprivation was significantly associated with presence of depressive symptoms. Integration of mental health evaluation and treatment into the HIV care provided for adolescents can be beneficial. More studies to delineate factors associated with depressed adolescents with HIV may add value to the body of knowledge and overall improvement of care.

A minimal approach to the scattering of physical massless bosons

NASA Astrophysics Data System (ADS)

Boels, Rutger H.; Luo, Hui

2018-05-01

Tree and loop level scattering amplitudes which involve physical massless bosons are derived directly from physical constraints such as locality, symmetry and unitarity, bypassing path integral constructions. Amplitudes can be projected onto a minimal basis of kinematic factors through linear algebra, by employing four dimensional spinor helicity methods or at its most general using projection techniques. The linear algebra analysis is closely related to amplitude relations, especially the Bern-Carrasco-Johansson relations for gluon amplitudes and the Kawai-Lewellen-Tye relations between gluons and graviton amplitudes. Projection techniques are known to reduce the computation of loop amplitudes with spinning particles to scalar integrals. Unitarity, locality and integration-by-parts identities can then be used to fix complete tree and loop amplitudes efficiently. The loop amplitudes follow algorithmically from the trees. A number of proof-of-concept examples are presented. These include the planar four point two-loop amplitude in pure Yang-Mills theory as well as a range of one loop amplitudes with internal and external scalars, gluons and gravitons. Several interesting features of the results are highlighted, such as the vanishing of certain basis coefficients for gluon and graviton amplitudes. Effective field theories are naturally and efficiently included into the framework. Dimensional regularisation is employed throughout; different regularisation schemes are worked out explicitly. The presented methods appear most powerful in non-supersymmetric theories in cases with relatively few legs, but with potentially many loops. For instance, in the introduced approach iterated unitarity cuts of four point amplitudes for non-supersymmetric gauge and gravity theories can be computed by matrix multiplication, generalising the so-called rung-rule of maximally supersymmetric theories. The philosophy of the approach to kinematics also leads to a technique to control colour quantum numbers of scattering amplitudes with matter, especially efficient in the adjoint and fundamental representations.

What interventions are used to improve exercise adherence in older people and what behavioural techniques are they based on? A systematic review.

PubMed

Room, Jonathan; Hannink, Erin; Dawes, Helen; Barker, Karen

2017-12-14

To conduct a systematic review of interventions used to improve exercise adherence in older people, to assess the effectiveness of these interventions and to evaluate the behavioural change techniques underpinning them using the Behaviour Change Technique Taxonomy (BCTT). Systematic review. A search was conducted on AMED, BNI, CINAHL, EMBASE, MEDLINE and PsychINFO databases. Randomised controlled trials that used an intervention to aid exercise adherence and an exercise adherence outcome for older people were included. Data were extracted with the use of a preprepared standardised form. Risk of bias was assessed with the Cochrane Collaboration's tool for assessing risk of bias. Interventions were classified according to the BCTT. Eleven studies were included in the review. Risk of bias was moderate to high. Interventions were classified into the following categories: comparison of behaviour, feedback and monitoring, social support, natural consequences, identity and goals and planning. Four studies reported a positive adherence outcome following their intervention. Three of these interventions were categorised in the feedback and monitoring category. Four studies used behavioural approaches within their study. These were social learning theory, socioemotional selectivity theory, cognitive behavioural therapy and self-efficacy. Seven studies did not report a behavioural approach. Interventions in the feedback and monitoring category showed positive outcomes, although there is insufficient evidence to recommend their use currently. There is need for better reporting, use and the development of theoretically derived interventions in the field of exercise adherence for older people. Robust measures of adherence, in order to adequately test these interventions would also be of use. CRD42015020884. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Large area silicon sheet by EFG. [Edge-defined Film-fed Growth

NASA Technical Reports Server (NTRS)

Rao, C. V. H.; Surek, T.; Mackintosh, B.; Ravi, K. V.; Wald, F. V.

1978-01-01

The edge-defined, film-fed growth (EFG) technique has been employed to grow silicon ribbons for photovoltaic applications. Considerable progress has been made in recent years in developing the technique to the point that long lengths of silicon ribbon can be routinely grown. In order to attain the full low-cost potential of the EFG technique, several further developments such as the growth of thinner and wider ribbons, increase in ribbon growth rate, and improvements in material quality are needed. The technological problems to be solved and the approaches employed to achieve these goals are discussed.

Improved 3-omega measurement of thermal conductivity in liquid, gases, and powders using a metal-coated optical fiber.

PubMed

Schiffres, Scott N; Malen, Jonathan A

2011-06-01

A novel 3ω thermal conductivity measurement technique called metal-coated 3ω is introduced for use with liquids, gases, powders, and aerogels. This technique employs a micron-scale metal-coated glass fiber as a heater/thermometer that is suspended within the sample. Metal-coated 3ω exceeds alternate 3ω based fluid sensing techniques in a number of key metrics enabling rapid measurements of small samples of materials with very low thermal effusivity (gases), using smaller temperature oscillations with lower parasitic conduction losses. Its advantages relative to existing fluid measurement techniques, including transient hot-wire, steady-state methods, and solid-wire 3ω are discussed. A generalized n-layer concentric cylindrical periodic heating solution that accounts for thermal boundary resistance is presented. Improved sensitivity to boundary conductance is recognized through this model. Metal-coated 3ω was successfully validated through a benchmark study of gases and liquids spanning two-orders of magnitude in thermal conductivity. © 2011 American Institute of Physics

A prospective examination of the impact of a supported employment program and employment on health-related quality of life, handicap, and disability among Veterans with SCI.

PubMed

Ottomanelli, Lisa; Barnett, Scott D; Goetz, Lance L

2013-10-01

To investigate impact of participation in a supported employment program and impact of employment itself on health-related quality of life (HRQOL), disability, and handicap among Veterans with spinal cord injury (SCI). We used a prospective, randomized, controlled, multi-site trial of supported employment (SE) versus treatment as usual (TAU) for vocational issues. Subjects were 157 Veterans with SCI who received either SE or TAU for vocational issues. Outcomes were examined in terms of type of vocational treatment received and whether competitive employment was obtained. Outcomes investigated were HRQOL as measured by the Veterans RAND 36-item health survey (VR-36), handicap as measured by the Craig Handicap Assessment and Reporting Technique (CHART), and disability as measured by the functional independence measure (FIM). Subjects were assessed at baseline and at 3, 6, 9, and 12 months. There were no significant differences between Veterans who participated in SE compared to those who received TAU in study measures. Participants obtaining competitive employment demonstrated significantly higher scores on the Social Integration, Mobility, and Occupation dimensions of the CHART. There were no observed differences in VR-36 scores or FIM scores for those obtaining competitive employment. This study suggests that employment has a positive effect on an individual's ability to participate in social relationships, move about their home and community, and spend time in productive and usual roles. Inability to detect differences across other domains of handicap or any changes in HRQOL may have been due to several factors including level and intensity of employment, insufficient follow-up period, or measurement limitations.

A review and content analysis of engagement, functionality, aesthetics, information quality, and change techniques in the most popular commercial apps for weight management.

PubMed

Bardus, Marco; van Beurden, Samantha B; Smith, Jane R; Abraham, Charles

2016-03-10

There are thousands of apps promoting dietary improvement, increased physical activity (PA) and weight management. Despite a growing number of reviews in this area, popular apps have not been comprehensively analysed in terms of features related to engagement, functionality, aesthetics, information quality, and content, including the types of change techniques employed. The databases containing information about all Health and Fitness apps on GP and iTunes (7,954 and 25,491 apps) were downloaded in April 2015. Database filters were applied to select the most popular apps available in both stores. Two researchers screened the descriptions selecting only weight management apps. Features, app quality and content were independently assessed using the Mobile App Rating Scale (MARS) and previously-defined categories of techniques relevant to behaviour change. Inter-coder reliabilities were calculated, and correlations between features explored. Of the 23 popular apps included in the review 16 were free (70%), 15 (65%) addressed weight control, diet and PA combined; 19 (83%) allowed behavioural tracking. On 5-point MARS scales, apps were of average quality (Md = 3.2, IQR = 1.4); "functionality" (Md = 4.0, IQR = 1.1) was the highest and "information quality" (Md = 2.0, IQR = 1.1) was the lowest domain. On average, 10 techniques were identified per app (range: 1-17) and of the 34 categories applied, goal setting and self-monitoring techniques were most frequently identified. App quality was positively correlated with number of techniques included (rho = .58, p < .01) and number of "technical" features (rho = .48, p < .05), which was also associated with the number of techniques included (rho = .61, p < .01). Apps that provided tracking used significantly more techniques than those that did not. Apps with automated tracking scored significantly higher in engagement, aesthetics, and overall MARS scores. Those that used change techniques previously associated with effectiveness (i.e., goal setting, self-monitoring and feedback) also had better "information quality". Popular apps assessed have overall moderate quality and include behavioural tracking features and a range of change techniques associated with behaviour change. These apps may influence behaviour, although more attention to information quality and evidence-based content are warranted to improve their quality.

75 FR 61251 - Proposed Information Collection (Request for Employment Information in Connection With Claim for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-04

... (Request for Employment Information in Connection With Claim for Disability Benefits) Activity: Comment... needed to determine a claimant's eligibility for increased disability benefits. DATES: Written comments... techniques or the use of other forms of information technology. Title: Request for Employment Information in...

78 FR 34175 - Proposed Information Collection (Request for Employment Information in Connection With Claim for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-06

... (Request for Employment Information in Connection With Claim for Disability Benefits) Activity: Comment... needed to determine a claimant's eligibility for increased disability benefits. DATES: Written comments... techniques or the use of other forms of information technology. Title: Request for Employment Information in...

Computational performance of Free Mesh Method applied to continuum mechanics problems

PubMed Central

YAGAWA, Genki

2011-01-01

The free mesh method (FMM) is a kind of the meshless methods intended for particle-like finite element analysis of problems that are difficult to handle using global mesh generation, or a node-based finite element method that employs a local mesh generation technique and a node-by-node algorithm. The aim of the present paper is to review some unique numerical solutions of fluid and solid mechanics by employing FMM as well as the Enriched Free Mesh Method (EFMM), which is a new version of FMM, including compressible flow and sounding mechanism in air-reed instruments as applications to fluid mechanics, and automatic remeshing for slow crack growth, dynamic behavior of solid as well as large-scale Eigen-frequency of engine block as applications to solid mechanics. PMID:21558753

One-Dimensional Signal Extraction Of Paper-Written ECG Image And Its Archiving

NASA Astrophysics Data System (ADS)

Zhang, Zhi-ni; Zhang, Hong; Zhuang, Tian-ge

1987-10-01

A method for converting paper-written electrocardiograms to one dimensional (1-D) signals for archival storage on floppy disk is presented here. Appropriate image processing techniques were employed to remove the back-ground noise inherent to ECG recorder charts and to reconstruct the ECG waveform. The entire process consists of (1) digitization of paper-written ECGs with an image processing system via a TV camera; (2) image preprocessing, including histogram filtering and binary image generation; (3) ECG feature extraction and ECG wave tracing, and (4) transmission of the processed ECG data to IBM-PC compatible floppy disks for storage and retrieval. The algorithms employed here may also be used in the recognition of paper-written EEG or EMG and may be useful in robotic vision.

Multistep fluorescence gated proportional counters

NASA Technical Reports Server (NTRS)

Ramsey, Brian D.; Weisskopf, Martin C.

1990-01-01

A proportional counter is introduced in which the levels of energy and spatial resolutions and background rejection permit the application of the device to X-ray astronomy. A multistep approach is employed in which photons cause a signal that triggers the system and measures the energy of the incident photon. The multistep approach permits good energy resolution from parallel geometry and from the imaging stage due to coupling of the imaging and amplification stages. The design also employs fluorescence gating to reduce background, a method that is compatible with the multistep technique. Use of the proportional counter is reported for NASA's supernova campaign, and the pair background is below 0.0001 counts/sq cm sec keV at the xenon k-edge. Potential improvements and applications are listed including the CASES, POF, and EXOSS mission programs.

Application of high-resolution, two-dimensional 1H and 13C nuclear magnetic resonance techniques to the characterization of lipid oxidation products in autoxidized linoleoyl/linolenoylglycerols.

PubMed

Silwood, C J; Grootveld, M

1999-07-01

Subjection of polyunsaturated fatty acid (PUFA)-rich culinary oils to standard frying episodes generates a range of lipid oxidation products (LOP), including saturated and alpha,beta-unsaturated aldehydes which arise from the thermally induced fragmentation of conjugated hydroperoxydiene precursors. Since such LOP are damaging to human health, we have employed high-resolution, two-dimensional 1H-1H relayed coherence transfer, 1H-1H total correlation, 1H-13C heteronuclear multiple quantum correlation, and 1H-1H J-resolved nuclear magnetic resonance (NMR) spectroscopic techniques to further elucidate the molecular structures of these components present in (i) a model linoleoylglycerol compound (1,3-dilinolein) allowed to autoxidize at ambient temperature and (ii) PUFA-rich culinary oils subjected to repeated frying episodes. The above techniques readily facilitate the resolution of selected vinylic and aldehydic resonances of LOP which appear as complex overlapping patterns in conventional one-dimensional spectra, particularly when employed in combination with solvent-induced spectral shift modifications. Hence, much useful multi-component information regarding the identity and/or classification of glycerol-bound conjugated hydroperoxydiene and hydroxydiene adducts, and saturated and alpha,beta-unsaturated aldehydes, present in autoxidized PUFA matrices is provided by these NMR methods. Such molecular information is of much value to researchers investigating the deleterious health effects of LOP available in the diet.

Novel laser induced photoacoustic spectroscopy for instantaneous trace detection of explosive materials.

PubMed

El-Sharkawy, Yasser H; Elbasuney, Sherif

2017-08-01

Laser photoacoustic spectroscopy (LPAS) is an attractive technology in terms of simplicity, ruggedness, and overall sensitivity; it detects the time dependent heat generated (thermo-elastic effect) in the target via interaction with pulsed optical radiation. This study reports on novel LPAS technique that offers instant and standoff detection capabilities of trace explosives. Over the current study, light is generated using pulsed Q-switched Nd:YAG laser; the generated photoacoustic response in stimulated explosive material offers signature values that depend on the optical, thermal, and acoustical properties. The generated acoustic waves were captured using piezoelectric transducer as well as novel customized optical sensor with remotely laser interferometer probe. A digital signal processing algorithm was employed to identify explosive material signatures via calculation of characteristic optical properties (absorption coefficient), sound velocity, and frequency response of the generated photoacoustic signal. Customized LPAS technique was employed for instantaneous trace detection of three main different high explosive materials including TNT, RDX, and HMX. The main outcome of this study is that the novel customized optical sensor signals were validated with traditional piezoelectric transducer. Furthermore, the customized optical sensor offered standoff detection capabilities (10cm), fast response, high sensitivity, and enhanced signal to noise ratio. This manuscript shaded the light on the instant detection of trace explosive materials from significant standoffs using novel customized LPAS technique. Copyright © 2017 Elsevier B.V. All rights reserved.

Changing Strategies of the Retrograde Approach for Chronic Total Occlusion During the Past 7 Years

PubMed Central

Muramatsu, Toshiya; Tsukahara, Reiko; Ito, Yoshiaki; Ishimori, Hiroshi; Park, Seung-Jung; Winter, Robert; Shokry, Khaled; Wang, Lefeng; Chen, Jiyan; Wang, Haichang

2013-01-01

Objective We reviewed the technical changes and results achieved with the retrograde approach since we introduced it 7 years ago. Subjects and Methods The subjects were 1,268 patients who were treated for CTO between January 2004 and December 2010. They were investigated with respect to the success rate, the frequency of employing the retrograde approach and its outcome, and other factors. Results The retrograde approach was employed in ∼30% of chronic total occlusion (CTO) patients (n = 281) and the retrograde guidewire success rate was 81.1%. The kissing wire technique was substituted for the retrograde approach in 126 of the 281 patients, with antegrade crossing of a guidewire being successful in 88 of them (70%). The retrograde approach was combined with the CART and reverse controlled antegrade retrograde tracking (CART) techniques in 22 and 21 patients, respectively. Among 83 patients treated with Corsair catheters, crossing of the CTO was achieved in 63. The overall procedural success rate was 79.7% (224 patients). Complications of the retrograde approach included collateral channel dissection (2.1%), channel perforation (1.7%), CTO perforation (1.7%), and donor artery occlusion (1.1%). Conclusion The success rate and safety of the retrograde approach are both satisfactory if the appropriate devices and techniques are selected. © 2012 Wiley Periodicals, Inc. PMID:22517670

Comparison of remote sensing image processing techniques to identify tornado damage areas from Landsat TM data

USGS Publications Warehouse

Myint, S.W.; Yuan, M.; Cerveny, R.S.; Giri, C.P.

2008-01-01

Remote sensing techniques have been shown effective for large-scale damage surveys after a hazardous event in both near real-time or post-event analyses. The paper aims to compare accuracy of common imaging processing techniques to detect tornado damage tracks from Landsat TM data. We employed the direct change detection approach using two sets of images acquired before and after the tornado event to produce a principal component composite images and a set of image difference bands. Techniques in the comparison include supervised classification, unsupervised classification, and objectoriented classification approach with a nearest neighbor classifier. Accuracy assessment is based on Kappa coefficient calculated from error matrices which cross tabulate correctly identified cells on the TM image and commission and omission errors in the result. Overall, the Object-oriented Approach exhibits the highest degree of accuracy in tornado damage detection. PCA and Image Differencing methods show comparable outcomes. While selected PCs can improve detection accuracy 5 to 10%, the Object-oriented Approach performs significantly better with 15-20% higher accuracy than the other two techniques. ?? 2008 by MDPI.

Comparison of Remote Sensing Image Processing Techniques to Identify Tornado Damage Areas from Landsat TM Data

PubMed Central

Myint, Soe W.; Yuan, May; Cerveny, Randall S.; Giri, Chandra P.

2008-01-01

Remote sensing techniques have been shown effective for large-scale damage surveys after a hazardous event in both near real-time or post-event analyses. The paper aims to compare accuracy of common imaging processing techniques to detect tornado damage tracks from Landsat TM data. We employed the direct change detection approach using two sets of images acquired before and after the tornado event to produce a principal component composite images and a set of image difference bands. Techniques in the comparison include supervised classification, unsupervised classification, and object-oriented classification approach with a nearest neighbor classifier. Accuracy assessment is based on Kappa coefficient calculated from error matrices which cross tabulate correctly identified cells on the TM image and commission and omission errors in the result. Overall, the Object-oriented Approach exhibits the highest degree of accuracy in tornado damage detection. PCA and Image Differencing methods show comparable outcomes. While selected PCs can improve detection accuracy 5 to 10%, the Object-oriented Approach performs significantly better with 15-20% higher accuracy than the other two techniques. PMID:27879757

A knowledge based system for scientific data visualization

NASA Technical Reports Server (NTRS)

Senay, Hikmet; Ignatius, Eve

1992-01-01

A knowledge-based system, called visualization tool assistant (VISTA), which was developed to assist scientists in the design of scientific data visualization techniques, is described. The system derives its knowledge from several sources which provide information about data characteristics, visualization primitives, and effective visual perception. The design methodology employed by the system is based on a sequence of transformations which decomposes a data set into a set of data partitions, maps this set of partitions to visualization primitives, and combines these primitives into a composite visualization technique design. Although the primary function of the system is to generate an effective visualization technique design for a given data set by using principles of visual perception the system also allows users to interactively modify the design, and renders the resulting image using a variety of rendering algorithms. The current version of the system primarily supports visualization techniques having applicability in earth and space sciences, although it may easily be extended to include other techniques useful in other disciplines such as computational fluid dynamics, finite-element analysis and medical imaging.

Apportionment of urban aerosol sources in Chongqing (China) using synergistic on-line techniques

NASA Astrophysics Data System (ADS)

Chen, Yang; Yang, Fumo

2016-04-01

The sources of ambient fine particulate matter (PM2.5) during wintertime at a background urban location in Chongqing (southwestern China) have been determined. Aerosol chemical composition analyses were performed using multiple on-line techniques, such as single particle aerosol mass spectrometer (SPAMS) for single particle chemical composition, on-line elemental carbon-organic carbon analyzer (on-line OC-EC), on-line X-ray fluorescence (XRF) for elements, and in-situ Gas and Aerosol Compositions monitor (IGAC) for water-soluble ions in PM2.5. All the datasets from these techniques have been adjusted to a 1-h time resolution for receptor model input. Positive matrix factorization (PMF) has been used for resolving aerosol sources. At least six sources, including domestic coal burning, biomass burning, dust, traffic, industrial and secondary/aged factors have been resolved and interpreted. The synergistic on-line techniques were helpful for identifying aerosol sources more clearly than when only employing the results from the individual techniques. This results are useful for better understanding of aerosol sources and atmospheric processes.

Mitigation of stress: new treatment alternatives.

PubMed

Subhani, Ahmad Rauf; Kamel, Nidal; Mohamad Saad, Mohamad Naufal; Nandagopal, Nanda; Kang, Kenneth; Malik, Aamir Saeed

2018-02-01

Complaints of stress are common in modern life. Psychological stress is a major cause of lifestyle-related issues, contributing to poor quality of life. Chronic stress impedes brain function, causing impairment of many executive functions, including working memory, decision making and attentional control. The current study sought to describe newly developed stress mitigation techniques, and their influence on autonomic and endocrine functions. The literature search revealed that the most frequently studied technique for stress mitigation was biofeedback (BFB). However, evidence suggests that neurofeedback (NFB) and noninvasive brain stimulation (NIBS) could potentially provide appropriate approaches. We found that recent studies of BFB methods have typically used measures of heart rate variability, respiration and skin conductance. In contrast, studies of NFB methods have typically utilized neurocomputation techniques employing electroencephalography, functional magnetic resonance imaging and near infrared spectroscopy. NIBS studies have typically utilized transcranial direct current stimulation methods. Mitigation of stress is a challenging but important research target for improving quality of life.

Techniques of biological contamination avoidance by atmospheric probes

NASA Technical Reports Server (NTRS)

Defrees, R. E.

1974-01-01

The likelihood of biologically contaminating a planet by an atmospheric probe has a low probability of occurring if the probe is kept biologically clean during terrestrial operations and if the structure remains in tact until the planets life zone is completely penetrated. High standards of cleanliness, monitoring and estimating for remedial actions must be maintained in a probe program. It is not a foregone conclusion, however, that heat sterilization needs to be employed. The use of several techniques having a good potential for lower probe costs are available and appear adequate to render a probe sterile within acceptable bounds. The techniques considered to be satisfactory for minimizing microbial load include: (1) combined heat (at 95-105 C) and gamma radiation; (2) short term heating at 105 + or - 5 C to inactivate all vegetative microbes; (3) irradiation routinely by ultraviolet light; (4) wiping by a bactericidal agent with or without a penetrant; and (5) cleanliness alone.

Cardiac Gene Therapy: Optimization of Gene Delivery Techniques In Vivo

PubMed Central

Katz, Michael G.; Swain, JaBaris D.; White, Jennifer D.; Low, David; Stedman, Hansell

2010-01-01

Abstract Vector-mediated cardiac gene therapy holds tremendous promise as a translatable platform technology for treating many cardiovascular diseases. The ideal technique is one that is efficient and practical, allowing for global cardiac gene expression, while minimizing collateral expression in other organs. Here we survey the available in vivo vector-mediated cardiac gene delivery methods—including transcutaneous, intravascular, intramuscular, and cardiopulmonary bypass techniques—with consideration of the relative merits and deficiencies of each. Review of available techniques suggests that an optimal method for vector-mediated gene delivery to the large animal myocardium would ideally employ retrograde and/or anterograde transcoronary gene delivery,extended vector residence time in the coronary circulation, an increased myocardial transcapillary gradient using physical methods, increased endothelial permeability with pharmacological agents, minimal collateral gene expression by isolation of the cardiac circulation from the systemic, and have low immunogenicity. PMID:19947886

Imaging challenges in biomaterials and tissue engineering

PubMed Central

Appel, Alyssa A.; Anastasio, Mark A.; Larson, Jeffery C.; Brey, Eric M.

2013-01-01

Biomaterials are employed in the fields of tissue engineering and regenerative medicine (TERM) in order to enhance the regeneration or replacement of tissue function and/or structure. The unique environments resulting from the presence of biomaterials, cells, and tissues result in distinct challenges in regards to monitoring and assessing the results of these interventions. Imaging technologies for three-dimensional (3D) analysis have been identified as a strategic priority in TERM research. Traditionally, histological and immunohistochemical techniques have been used to evaluate engineered tissues. However, these methods do not allow for an accurate volume assessment, are invasive, and do not provide information on functional status. Imaging techniques are needed that enable non-destructive, longitudinal, quantitative, and three-dimensional analysis of TERM strategies. This review focuses on evaluating the application of available imaging modalities for assessment of biomaterials and tissue in TERM applications. Included is a discussion of limitations of these techniques and identification of areas for further development. PMID:23768903

Physics faculty beliefs and values about the teaching and learning of problem solving. II. Procedures for measurement and analysis

NASA Astrophysics Data System (ADS)

Henderson, Charles; Yerushalmi, Edit; Kuo, Vince H.; Heller, Kenneth; Heller, Patricia

2007-12-01

To identify and describe the basis upon which instructors make curricular and pedagogical decisions, we have developed an artifact-based interview and an analysis technique based on multilayered concept maps. The policy capturing technique used in the interview asks instructors to make judgments about concrete instructional artifacts similar to those they likely encounter in their teaching environment. The analysis procedure alternatively employs both an a priori systems view analysis and an emergent categorization to construct a multilayered concept map, which is a hierarchically arranged set of concept maps where child maps include more details than parent maps. Although our goal was to develop a model of physics faculty beliefs about the teaching and learning of problem solving in the context of an introductory calculus-based physics course, the techniques described here are applicable to a variety of situations in which instructors make decisions that influence teaching and learning.

Fiber Optic Thermal Detection of Composite Delaminations

NASA Technical Reports Server (NTRS)

Wu, Meng-Chou; Winfree, William P.

2011-01-01

A recently developed technique is presented for thermographic detection of delaminations in composites by performing temperature measurements with fiber optic Bragg gratings. A single optical fiber with multiple Bragg gratings employed as surface temperature sensors was bonded to the surface of a composite with subsurface defects. The investigated structure was a 10-ply composite specimen with prefabricated delaminations of various sizes and depths. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The data obtained from grating sensors were analyzed with thermal modeling techniques of conventional thermography to reveal particular characteristics of the interested areas. Results were compared and found to be consistent with the calculations using numerical simulation techniques. Also discussed are methods including various heating sources and patterns, and their limitations for performing in-situ structural health monitoring.

The Chemistry of Paper Preservation: Part 1. The Aging of Paper and Conservation Techniques

NASA Astrophysics Data System (ADS)

Carter, Henry A.

1996-05-01

This study provides an introduction to the problem of the aging of paper and the conservation techniques that are currently being employed in paper preservation. The chemical reactions that are responsible for the aging of paper are discussed with the conclusion that acid-catalyzed hydrolysis is the predominant mechanism for cellulose degradation and strength loss. A description and the chemistry of a number of mass deacidification methods are presented. The more viable deacidification methods include the DEZ, Wei T'o, FMC, Bookkeeper, Viennese, Book Preservation Associates, Sable and the Batelle processes. A summary of the literature on the evaluations of these processes is presented, and the benefits and limitations of the mass deacidification methods are discussed. Other conservation techniques such as paper strengthening, conservation bleaching, and pest control are briefly introduced, followed by an introduction to alkaline papermaking.

Laser desorption ionization mass spectrometry: Recent progress in matrix-free and label-assisted techniques.

PubMed

Mandal, Arundhoti; Singha, Monisha; Addy, Partha Sarathi; Basak, Amit

2017-10-13

The MALDI-based mass spectrometry, over the last three decades, has become an important analytical tool. It is a gentle ionization technique, usually applicable to detect and characterize analytes with high molecular weights like proteins and other macromolecules. The earlier difficulty of detection of analytes with low molecular weights like small organic molecules and metal ion complexes with this technique arose due to the cluster of peaks in the low molecular weight region generated from the matrix. To detect such molecules and metal ion complexes, a four-prong strategy has been developed. These include use of alternate matrix materials, employment of new surface materials that require no matrix, use of metabolites that directly absorb the laser light, and the laser-absorbing label-assisted LDI-MS (popularly known as LALDI-MS). This review will highlight the developments with all these strategies with a special emphasis on LALDI-MS. © 2017 Wiley Periodicals, Inc.

Software error detection

NASA Technical Reports Server (NTRS)

Buechler, W.; Tucker, A. G.

1981-01-01

Several methods were employed to detect both the occurrence and source of errors in the operational software of the AN/SLQ-32. A large embedded real time electronic warfare command and control system for the ROLM 1606 computer are presented. The ROLM computer provides information about invalid addressing, improper use of privileged instructions, stack overflows, and unimplemented instructions. Additionally, software techniques were developed to detect invalid jumps, indices out of range, infinte loops, stack underflows, and field size errors. Finally, data are saved to provide information about the status of the system when an error is detected. This information includes I/O buffers, interrupt counts, stack contents, and recently passed locations. The various errors detected, techniques to assist in debugging problems, and segment simulation on a nontarget computer are discussed. These error detection techniques were a major factor in the success of finding the primary cause of error in 98% of over 500 system dumps.

Multisample conversion of water to hydrogen by zinc for stable isotope determination

USGS Publications Warehouse

Kendall, C.; Coplen, T.B.

1985-01-01

Two techniques for the conversion of water to hydrogen for stable isotope ratio determination have been developed that are especially suited for automated multisample analysis. Both procedures involve reaction of zinc shot with a water sample at 450 ??C. in one method designed for water samples in bottles, the water is put in capillaries and is reduced by zinc in reaction vessels; overall savings in sample preparation labor of 75% have been realized over the standard uranium reduction technique. The second technique is for waters evolved under vacuum and is a sealed-tube method employing 9 mm o.d. quartz tubing. Problems inherent with zinc reduction include surface inhomogeneity of the zinc and exchange of hydrogen both with the zinc and with the glass walls of the vessels. For best results, water/zinc and water/glass surface area ratios of vessels should be kept as large as possible.

A hybrid lightwave transmission system based on light injection/optoelectronic feedback techniques and fiber-VLLC integration

NASA Astrophysics Data System (ADS)

Tsai, Wen-Shing; Lu, Hai-Han; Li, Chung-Yi; Chen, Bo-Rui; Lin, Hung-Hsien; Lin, Dai-Hua

2016-04-01

A hybrid lightwave transmission system based on light injection/optoelectronic feedback techniques and fiber-visible laser light communication (VLLC) integration is proposed and experimentally demonstrated. To be the first one of its kind in employing light injection and optoelectronic feedback techniques in a fiber-VLLC integration lightwave transmission system, the light is successfully directly modulated with Community Access Television (CATV), 16-QAM, and 16-QAM-OFDM signals. Over a 40 km SMF and a 10 m free-space VLLC transport, good performances of carrier-to-noise ratio (CNR)/composite second-order (CSO)/composite triple-beat (CTB)/bit error rate (BER) are achieved for CATV/16-QAM/16-QAM-OFDM signals transmission. Such a hybrid lightwave transmission system would be very useful since it can provide broadband integrated services including CATV, Internet, and telecommunication services over both distribute fiber and in-building networks.

A review of surgical repair methods and patient outcomes for gluteal tendon tears.

PubMed

Ebert, Jay R; Bucher, Thomas A; Ball, Simon V; Janes, Gregory C

2015-01-01

Advanced hip imaging and surgical findings have demonstrated that a common cause of greater trochanteric pain syndrome (GTPS) is gluteal tendon tears. Conservative measures are initially employed to treat GTPS and manage gluteal tears, though patients frequently undergo multiple courses of non-operative treatment with only temporary pain relief. Therefore, a number of surgical treatment options for recalcitrant GTPS associated with gluteal tears have been reported. These have included open trans-osseous or bone anchored suture techniques, endoscopic methods and the use of tendon augmentation for repair reinforcement. This review describes the anatomy, pathophysiology and clinical presentation of gluteal tendon tears. Surgical techniques and patient reported outcomes are presented. This review demonstrates that surgical repair can result in improved patient outcomes, irrespective of tear aetiology, and suggests that the patient with "trochanteric bursitis" should be carefully assessed as newer surgical techniques show promise for a condition that historically has been managed conservatively.

EISCAT Aperture Synthesis Imaging (EASI _3D) for the EISCAT_3D Project

NASA Astrophysics Data System (ADS)

La Hoz, Cesar; Belyey, Vasyl

2012-07-01

Aperture Synthesis Imaging Radar (ASIR) is one of the technologies adopted by the EISCAT_3D project to endow it with imaging capabilities in 3-dimensions that includes sub-beam resolution. Complemented by pulse compression, it will provide 3-dimensional images of certain types of incoherent scatter radar targets resolved to about 100 metres at 100 km range, depending on the signal-to-noise ratio. This ability will open new research opportunities to map small structures associated with non-homogeneous, unstable processes such as aurora, summer and winter polar radar echoes (PMSE and PMWE), Natural Enhanced Ion Acoustic Lines (NEIALs), structures excited by HF ionospheric heating, meteors, space debris, and others. The underlying physico-mathematical principles of the technique are the same as the technique employed in radioastronomy to image stellar objects; both require sophisticated inversion techniques to obtain reliable images.

Techniques and Tools of NASA's Space Shuttle Columbia Accident Investigation

NASA Technical Reports Server (NTRS)

McDanels, Steve J.

2005-01-01

The Space Shuttle Columbia accident investigation was a fusion of many disciplines into a single effort. From the recovery and reconstruction of the debris, Figure 1, to the analysis, both destructive and nondestructive, of chemical and metallurgical samples, Figure 2, a multitude of analytical techniques and tools were employed. Destructive and non-destructive testing were utilized in tandem to determine if a breach in the left wing of the Orbiter had occurred, and if so, the path of the resultant high temperature plasma flow. Nondestructive analysis included topometric scanning, laser mapping, and real-time radiography. These techniques were useful in constructing a three dimensional virtual representation of the reconstruction project, specifically the left wing leading edge reinforced carbon/carbon heat protectant panels. Similarly, they were beneficial in determining where sampling should be performed on the debris. Analytic testing included such techniques as Energy Dispersive Electron Microprobe Analysis (EMPA), Electron Spectroscopy Chemical Analysis (ESCA), and X-Ray dot mapping; these techniques related the characteristics of intermetallics deposited on the leading edge of the left wing adjacent to the location of a suspected plasma breach during reentry. The methods and results of the various analyses, along with their implications into the accident, are discussed, along with the findings and recommendations of the Columbia Accident Investigation Board. Likewise, NASA's Return To Flight efforts are highlighted.

Musculoskeletal modelling in dogs: challenges and future perspectives.

PubMed

Dries, Billy; Jonkers, Ilse; Dingemanse, Walter; Vanwanseele, Benedicte; Vander Sloten, Jos; van Bree, Henri; Gielen, Ingrid

2016-05-18

Musculoskeletal models have proven to be a valuable tool in human orthopaedics research. Recently, veterinary research started taking an interest in the computer modelling approach to understand the forces acting upon the canine musculoskeletal system. While many of the methods employed in human musculoskeletal models can applied to canine musculoskeletal models, not all techniques are applicable. This review summarizes the important parameters necessary for modelling, as well as the techniques employed in human musculoskeletal models and the limitations in transferring techniques to canine modelling research. The major challenges in future canine modelling research are likely to centre around devising alternative techniques for obtaining maximal voluntary contractions, as well as finding scaling factors to adapt a generalized canine musculoskeletal model to represent specific breeds and subjects.

Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples

USGS Publications Warehouse

Steinheimer, T.R.; Brooks, M.G.

1984-01-01

A multi-residue method is described for the determination of triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0.1 ??g/L in a 1-litre sample. Three different natural water samples were used for error analysis via evaluation of recovery efficiencies and estimation of overall method precision. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.A multi-residue method is described for the determination of triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0. 1 mu g/L in a 1-litre sample. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.

AMT-200S Motor Glider Parameter and Performance Estimation

NASA Technical Reports Server (NTRS)

Taylor, Brian R.

2011-01-01

Parameter and performance estimation of an instrumented motor glider was conducted at the National Aeronautics and Space Administration Dryden Flight Research Center in order to provide the necessary information to create a simulation of the aircraft. An output-error technique was employed to generate estimates from doublet maneuvers, and performance estimates were compared with results from a well-known flight-test evaluation of the aircraft in order to provide a complete set of data. Aircraft specifications are given along with information concerning instrumentation, flight-test maneuvers flown, and the output-error technique. Discussion of Cramer-Rao bounds based on both white noise and colored noise assumptions is given. Results include aerodynamic parameter and performance estimates for a range of angles of attack.

Close-packed monolayer self-assembly of silica nanospheres assisted by infrared irradiation

NASA Astrophysics Data System (ADS)

Minh, Nguyen Van; Hue, Nguyen Thi; Lien, Nghiem Thi Ha; Hoang, Chu Manh

2018-01-01

In this paper, we report on a fast and cost-effective drop coating technique for the self-assembly of silica nano-spheres from a mono-dispersed colloidal suspension into close-packed monolayer (CMP) on hydrophilic single-crystal silicon substrate. The technique includes the self-assembly of silica nano-spheres on slanted silicon substrate and infrared irradiation during evaporation process of the coated droplet. The influence of the substrate slant angle and infrared irradiation on the formation of silica nano-sphere monolayer is investigated. This achievement is promising for various applications, such as a mask layer for nano-sphere lithography that is employed for producing fundamental elements in photonics, plasmonics, and solar cell. [Figure not available: see fulltext.

Development of Low Cost Satellite Communications System for Helicopters and General Aviation

NASA Technical Reports Server (NTRS)

Farazian, K.; Abbe, B.; Divsalar, D.; Raphaeli, D.; Tulintseff, A.; Wu, T.; Hinedi, S.

1994-01-01

In this paper, the development of low-cost satellite communications (SATCOM) system for helicopters and General Aviation (GA) aircrafts is described. System design and standards analysis have been conducted to meet the low-cost, light-weight, small-size and low-power system requirements for helicopters and GA aircraft environments. Other specific issues investigated include coding schemes, spatial diversity, and antenna arraying techniques. Coding schemes employing Channel State Information (CSI) and inverleaving have been studied in order to mitigate severe banking angle fading and the periodic RF signal blockage due to the helicopter rotor blades. In addition, space diversity and antenna arraying techniques have been investigated to further reduce the fading effects and increase the link margin.

Low-temperature solvothermal approach to the synthesis of La4Ni3O8 by topotactic oxygen deintercalation.

PubMed

Blakely, Colin K; Bruno, Shaun R; Poltavets, Viktor V

2011-07-18

A chimie douce solvothermal reduction method is proposed for topotactic oxygen deintercalation of complex metal oxides. Four different reduction techniques were employed to qualitatively identify the relative reduction activity of each including reduction with H(2) and NaH, solution-based reduction using metal hydrides at ambient pressure, and reduction under solvothermal conditions. The reduction of the Ruddlesden-Popper nickelate La(4)Ni(3)O(10) was used as a test case to prove the validity of the method. The completely reduced phase La(4)Ni(3)O(8) was produced via the solvothermal technique at 150 °C--a lower temperature than by other more conventional solid state oxygen deintercalation methods.

Measurement of the static and dynamic coefficients of a cross-type parachute in subsonic flow

NASA Technical Reports Server (NTRS)

Shpund, Zalman; Levin, Daniel

1991-01-01

An experimental parametric investigation of the aerodynamic qualities of cross-type parachutes was performed in a subsonic wind tunnel, using a new experimental technique. This investigation included the measurement of the static and dynamic aerodynamic coefficients, utilizing the measuring apparatus modified specifically for this type of testing. It is shown that the static aerodynamic coefficients of several configurations are in good agreement with available data, and assisted in validating the experimental technique employed. Two configuration parameters were varied in the static tests, the cord length and the canopy aspect ratio, with both parameters having a similar effect on the drag measurement, i.e., any increase in either of them increased the effective blocking area, and therefore the axial force.

Limited receptive area neural classifier for recognition of swallowing sounds using continuous wavelet transform.

PubMed

Makeyev, Oleksandr; Sazonov, Edward; Schuckers, Stephanie; Lopez-Meyer, Paulo; Melanson, Ed; Neuman, Michael

2007-01-01

In this paper we propose a sound recognition technique based on the limited receptive area (LIRA) neural classifier and continuous wavelet transform (CWT). LIRA neural classifier was developed as a multipurpose image recognition system. Previous tests of LIRA demonstrated good results in different image recognition tasks including: handwritten digit recognition, face recognition, metal surface texture recognition, and micro work piece shape recognition. We propose a sound recognition technique where scalograms of sound instances serve as inputs of the LIRA neural classifier. The methodology was tested in recognition of swallowing sounds. Swallowing sound recognition may be employed in systems for automated swallowing assessment and diagnosis of swallowing disorders. The experimental results suggest high efficiency and reliability of the proposed approach.

Spectral analysis and filtering techniques in digital spatial data processing

USGS Publications Warehouse

Pan, Jeng-Jong

1989-01-01

A filter toolbox has been developed at the EROS Data Center, US Geological Survey, for retrieving or removing specified frequency information from two-dimensional digital spatial data. This filter toolbox provides capabilities to compute the power spectrum of a given data and to design various filters in the frequency domain. Three types of filters are available in the toolbox: point filter, line filter, and area filter. Both the point and line filters employ Gaussian-type notch filters, and the area filter includes the capabilities to perform high-pass, band-pass, low-pass, and wedge filtering techniques. These filters are applied for analyzing satellite multispectral scanner data, airborne visible and infrared imaging spectrometer (AVIRIS) data, gravity data, and the digital elevation models (DEM) data. -from Author

Novel grid-based optical Braille conversion: from scanning to wording

NASA Astrophysics Data System (ADS)

Yoosefi Babadi, Majid; Jafari, Shahram

2011-12-01

Grid-based optical Braille conversion (GOBCO) is explained in this article. The grid-fitting technique involves processing scanned images taken from old hard-copy Braille manuscripts, recognising and converting them into English ASCII text documents inside a computer. The resulted words are verified using the relevant dictionary to provide the final output. The algorithms employed in this article can be easily modified to be implemented on other visual pattern recognition systems and text extraction applications. This technique has several advantages including: simplicity of the algorithm, high speed of execution, ability to help visually impaired persons and blind people to work with fax machines and the like, and the ability to help sighted people with no prior knowledge of Braille to understand hard-copy Braille manuscripts.

Net Shaped Component Fabrication of Refractory Metal Alloys using Vacuum Plasma Spraying

NASA Technical Reports Server (NTRS)

Sen, S.; ODell, S.; Gorti, S.; Litchford, R.

2006-01-01

The vacuum plasma spraying (VPS) technique was employed to produce dense and net shaped components of a new tungsten-rhenium (W-Re) refractory metal alloy. The fine grain size obtained using this technique enhanced the mechanical properties of the alloy at elevated temperatures. The alloy development also included incorporation of thermodynamically stable dispersion phases to pin down grain boundaries at elevated temperatures and thereby circumventing the inherent problem of recrystallization of refractory alloys at elevated temperatures. Requirements for such alloys as related to high temperature space propulsion components will be discussed. Grain size distribution as a function of cooling rate and dispersion phase loading will be presented. Mechanical testing and grain growth results as a function of temperature will also be discussed.

Thermal indicator for wells

DOEpatents

Gaven, Jr., Joseph V.; Bak, Chan S.

1983-01-01

Minute durable plate-like thermal indicators are employed for precision measuring static and dynamic temperatures of well drilling fluids. The indicators are small enough and sufficiently durable to be circulated in the well with drilling fluids during the drilling operation. The indicators include a heat resistant indicating layer, a coacting meltable solid component and a retainer body which serves to unitize each indicator and which may carry permanent indicator identifying indicia. The indicators are recovered from the drilling fluid at ground level by known techniques.

[Studies on the chemical constituents from the roots of Kalopanax septemlobus].

PubMed

Yao, Huan-Kai; Duan, Jing-Yu; Li, Yan; Wang, Jian-Hui; Yin, Xiao-Xing; Duan, Hong-Quan

2011-05-01

To investigate the chemical constituents of Kalopanax septemlobus. Chromatographic techniques including silica gel, gel, semi-preparative HPLC and PTLC as well as recrystallization were employed in the isolation and purification, and the structures were elucidated by spectral analysis and physical and chemical properties. 6 compounds were identified as liriodendrin (1), (-) -syringarenol (2), trans-coniferyl aldehyde (3), trans-caffeic acid (4), beta-daucosterol (5), beta-sitosterol (6). Compounds 2 -5 are obtained from this genus for the first time.

Standoff detection of trace amounts of solids by nonlinear Raman spectroscopy using shaped femtosecond pulses

NASA Astrophysics Data System (ADS)

Katz, O.; Natan, A.; Silberberg, Y.; Rosenwaks, S.

2008-04-01

We demonstrate a single-beam, standoff (>10m) detection and identification of various materials including minute amounts of explosives under ambient light conditions. This is obtained by multiplex coherent anti-Stokes Raman scattering spectroscopy (CARS) using a single femtosecond phase-shaped laser pulse. We exploit the strong nonresonant background for amplification of the backscattered resonant CARS signals by employing a homodyne detection scheme. The simple and highly sensitive spectroscopic technique has a potential for hazardous materials standoff detection applications.

Simulation analysis of the transparency of cornea and sclera

NASA Astrophysics Data System (ADS)

Yang, Chih-Yao; Tseng, Snow H.

2017-02-01

Both consist of collagen fibrils, sclera is opaque whereas cornea is transparent for optical wavelengths. By employing the pseudospectral time-domain (PSTD) simulation technique, we model light impinging upon cornea and sclera, respectively. To analyze the scattering characteristics of light, the cornea and sclera are modeled by different sizes and arrangements of the non-absorbing collagen fibrils. Various factors are analyzed, including the wavelength of incident light, the thickness of the scattering media, position of the collagen fibrils, size distribution of the fibrils.

Physiopathological Hypothesis of Cellulite

PubMed Central

de Godoy, José Maria Pereira; de Godoy, Maria de Fátima Guerreiro

2009-01-01

A series of questions are asked concerning this condition including as regards to its name, the consensus about the histopathological findings, physiological hypothesis and treatment of the disease. We established a hypothesis for cellulite and confirmed that the clinical response is compatible with this hypothesis. Hence this novel approach brings a modern physiological concept with physiopathologic basis and clinical proof of the hypothesis. We emphasize that the choice of patient, correct diagnosis of cellulite and the technique employed are fundamental to success. PMID:19756187

Liquid-Phase Circulation and Mixing in Multicomponent Droplets Vaporizing in a Laminar Convective Environment

DTIC Science & Technology

1993-10-15

included an f/2.8 dual port long-distance microscope coupled to a black d•rl white CCD video camera. A long-pass filter (with a cut-off at 530 nm) was...evaporation rates of multicomponent droplets is needed for the calibration of exciplex -based vapor/liquid visualization techniques that are employed today in...Publishing Co., Houston. Texas. Hanlon. T. R.. and Melton. L. A. (1992). Exciplex fluorescence thermometry of falling hexadecane droplets. Journal of Heat

The recalibration of the IUE scientific instrument

NASA Technical Reports Server (NTRS)

Imhoff, Catherine L.; Oliversen, Nancy A.; Nichols-Bohlin, Joy; Casatella, Angelo; Lloyd, Christopher

1988-01-01

The IUE instrument was recalibrated because of long time-scale changes in the scientific instrument, a better understanding of the performance of the instrument, improved sets of calibration data, and improved analysis techniques. Calibrations completed or planned include intensity transfer functions (ITF), low-dispersion absolute calibrations, high-dispersion ripple corrections and absolute calibrations, improved geometric mapping of the ITFs to spectral images, studies to improve the signal-to-noise, enhanced absolute calibrations employing corrections for time, temperature, and aperture dependence, and photometric and geometric calibrations for the FES.

Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance

NASA Technical Reports Server (NTRS)

Molina, Mario J.

2004-01-01

The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HCl vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow-chemical ionization mass spectrometry and optical ellipsometry, among others.

Lithium cluster anions: photoelectron spectroscopy and ab initio calculations.

PubMed

Alexandrova, Anastassia N; Boldyrev, Alexander I; Li, Xiang; Sarkas, Harry W; Hendricks, Jay H; Arnold, Susan T; Bowen, Kit H

2011-01-28

Structural and energetic properties of small, deceptively simple anionic clusters of lithium, Li(n)(-), n = 3-7, were determined using a combination of anion photoelectron spectroscopy and ab initio calculations. The most stable isomers of each of these anions, the ones most likely to contribute to the photoelectron spectra, were found using the gradient embedded genetic algorithm program. Subsequently, state-of-the-art ab initio techniques, including time-dependent density functional theory, coupled cluster, and multireference configurational interactions methods, were employed to interpret the experimental spectra.

Low-fat and delicious: can we break the taste barrier?

PubMed

Kostas, G

1997-07-01

No matter how healthy a food or recipe might be, if it does not taste good, people will not eat it. The professional and personal challenge is to find ways to cook favorite foods in a low-fat and delicious style to maintain health while enjoying foods without guilt. A number of strategies can be employed to reach that goal, including ingredient choices, low-fat product substitutes, cookware, cooking techniques, seasonings, basic cooking and recipe modifications, and the creation of new recipes.

Incorporating social media into dermatologic education.

PubMed

Ko, Lauren N; Rana, Jasmine; Burgin, Susan

2017-10-15

In the current digital age, medical education has slowly evolved from the largely lecture-based teaching style of the past to incorporate more interactive pedagogical techniques, including use of social media. Already used readily by millennial trainees and clinicians, social media can also be used in innovative ways to teach trainees and facilitate continuing education among practicing clinicians. In this commentary, we discuss many learning benefits of social media and review potential pitfalls of employing social media in both trainee and physician dermatological education.

Deep anistropic shell program for tire analysis

NASA Technical Reports Server (NTRS)

Andersen, C. M.

1981-01-01

A finite element program was constructed to model the mechanical response of a tire, treated as a deep anisotropic shell, to specified static loads. The program is based on a Sanders Budiansky type shell theory with the effects of transverse shear deformation and bending-extensional coupling included. A displacement formulation is used together with a total Lagrangian description of the deformation. Sixteen-node quadrilateral elements with bicubic shape functions are employed. The Noor basis reduction technique and various type of symmetry considerations serve to improve the computational efficiency.

Identification of quasi-steady compressor characteristics from transient data

NASA Technical Reports Server (NTRS)

Nunes, K. B.; Rock, S. M.

1984-01-01

The principal goal was to demonstrate that nonlinear compressor map parameters, which govern an in-stall response, can be identified from test data using parameter identification techniques. The tasks included developing and then applying an identification procedure to data generated by NASA LeRC on a hybrid computer. Two levels of model detail were employed. First was a lumped compressor rig model; second was a simplified turbofan model. The main outputs are the tools and procedures generated to accomplish the identification.

Bit-serial neuroprocessor architecture

NASA Technical Reports Server (NTRS)

Tawel, Raoul (Inventor)

2001-01-01

A neuroprocessor architecture employs a combination of bit-serial and serial-parallel techniques for implementing the neurons of the neuroprocessor. The neuroprocessor architecture includes a neural module containing a pool of neurons, a global controller, a sigmoid activation ROM look-up-table, a plurality of neuron state registers, and a synaptic weight RAM. The neuroprocessor reduces the number of neurons required to perform the task by time multiplexing groups of neurons from a fixed pool of neurons to achieve the successive hidden layers of a recurrent network topology.

Modeling of switching regulator power stages with and without zero-inductor-current dwell time

NASA Technical Reports Server (NTRS)

Lee, F. C.; Yu, Y.; Triner, J. E.

1976-01-01

State space techniques are employed to derive accurate models for buck, boost, and buck/boost converter power stages operating with and without zero-inductor-current dwell time. A generalized procedure is developed which treats the continuous-inductor-current mode without the dwell time as a special case of the discontinuous-current mode, when the dwell time vanishes. An abrupt change of system behavior including a reduction of the system order when the dwell time appears is shown both analytically and experimentally.

Supportive Psychotherapy with the Dual Diagnosis Patient

PubMed Central

2008-01-01

Psychiatrists and other mental health professionals can offer much in the care of patients with intellectual disabilities, including state-of-the-art medication regimens, psychotherapy, and other behavior therapies. Individuals with intellectual disabilities experience the full range of mental illnesses, but are often thought to be incapable of participating in or responding to psychotherapy. The following composite cases illustrate some of the psychotherapy techniques employed in a community psychiatry setting that serves patients with intellectual disabilities and co-occurring mental illness. PMID:19727299

Application of differential transformation method for solving dengue transmission mathematical model

NASA Astrophysics Data System (ADS)

Ndii, Meksianis Z.; Anggriani, Nursanti; Supriatna, Asep K.

2018-03-01

The differential transformation method (DTM) is a semi-analytical numerical technique which depends on Taylor series and has application in many areas including Biomathematics. The aim of this paper is to employ the differential transformation method (DTM) to solve system of non-linear differential equations for dengue transmission mathematical model. Analytical and numerical solutions are determined and the results are compared to that of Runge-Kutta method. We found a good agreement between DTM and Runge-Kutta method.

General Monte Carlo reliability simulation code including common mode failures and HARP fault/error-handling

NASA Technical Reports Server (NTRS)

Platt, M. E.; Lewis, E. E.; Boehm, F.

1991-01-01

A Monte Carlo Fortran computer program was developed that uses two variance reduction techniques for computing system reliability applicable to solving very large highly reliable fault-tolerant systems. The program is consistent with the hybrid automated reliability predictor (HARP) code which employs behavioral decomposition and complex fault-error handling models. This new capability is called MC-HARP which efficiently solves reliability models with non-constant failures rates (Weibull). Common mode failure modeling is also a specialty.

Physical vs. photolithographic patterning of plasma polymers: an investigation by ToF-SSIMS and multivariate analysis

PubMed Central

Mishra, Gautam; Easton, Christopher D.; McArthur, Sally L.

2009-01-01

Physical and photolithographic techniques are commonly used to create chemical patterns for a range of technologies including cell culture studies, bioarrays and other biomedical applications. In this paper, we describe the fabrication of chemical micropatterns from commonly used plasma polymers. Atomic force microcopy (AFM) imaging, Time-of-Flight Static Secondary Ion Mass Spectrometry (ToF-SSIMS) imaging and multivariate analysis have been employed to visualize the chemical boundaries created by these patterning techniques and assess the spatial and chemical resolution of the patterns. ToF-SSIMS analysis demonstrated that well defined chemical and spatial boundaries were obtained from photolithographic patterning, while the resolution of physical patterning via a transmission electron microscopy (TEM) grid varied depending on the properties of the plasma system including the substrate material. In general, physical masking allowed diffusion of the plasma species below the mask and bleeding of the surface chemistries. Multivariate analysis techniques including Principal Component Analysis (PCA) and Region of Interest (ROI) assessment were used to investigate the ToF-SSIMS images of a range of different plasma polymer patterns. In the most challenging case, where two strongly reacting polymers, allylamine and acrylic acid were deposited, PCA confirmed the fabrication of micropatterns with defined spatial resolution. ROI analysis allowed for the identification of an interface between the two plasma polymers for patterns fabricated using the photolithographic technique which has been previously overlooked. This study clearly demonstrated the versatility of photolithographic patterning for the production of multichemistry plasma polymer arrays and highlighted the need for complimentary characterization and analytical techniques during the fabrication plasma polymer micropatterns. PMID:19950941

Infrared Spectroscopy of Explosives Residues: Measurement Techniques and Spectral Analysis

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

Phillips, Mark C.; Bernacki, Bruce E.

2015-03-11

Infrared laser spectroscopy of explosives is a promising technique for standoff and non-contact detection applications. However, the interpretation of spectra obtained in typical standoff measurement configurations presents numerous challenges. Understanding the variability in observed spectra from explosives residues and particles is crucial for design and implementation of detection algorithms with high detection confidence and low false alarm probability. We discuss a series of infrared spectroscopic techniques applied toward measuring and interpreting the reflectance spectra obtained from explosives particles and residues. These techniques utilize the high spectral radiance, broad tuning range, rapid wavelength tuning, high scan reproducibility, and low noise ofmore » an external cavity quantum cascade laser (ECQCL) system developed at Pacific Northwest National Laboratory. The ECQCL source permits measurements in configurations which would be either impractical or overly time-consuming with broadband, incoherent infrared sources, and enables a combination of rapid measurement speed and high detection sensitivity. The spectroscopic methods employed include standoff hyperspectral reflectance imaging, quantitative measurements of diffuse reflectance spectra, reflection-absorption infrared spectroscopy, microscopic imaging and spectroscopy, and nano-scale imaging and spectroscopy. Measurements of explosives particles and residues reveal important factors affecting observed reflectance spectra, including measurement geometry, substrate on which the explosives are deposited, and morphological effects such as particle shape, size, orientation, and crystal structure.« less

A Passive System Reliability Analysis for a Station Blackout

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

Brunett, Acacia; Bucknor, Matthew; Grabaskas, David

2015-05-03

The latest iterations of advanced reactor designs have included increased reliance on passive safety systems to maintain plant integrity during unplanned sequences. While these systems are advantageous in reducing the reliance on human intervention and availability of power, the phenomenological foundations on which these systems are built require a novel approach to a reliability assessment. Passive systems possess the unique ability to fail functionally without failing physically, a result of their explicit dependency on existing boundary conditions that drive their operating mode and capacity. Argonne National Laboratory is performing ongoing analyses that demonstrate various methodologies for the characterization of passivemore » system reliability within a probabilistic framework. Two reliability analysis techniques are utilized in this work. The first approach, the Reliability Method for Passive Systems, provides a mechanistic technique employing deterministic models and conventional static event trees. The second approach, a simulation-based technique, utilizes discrete dynamic event trees to treat time- dependent phenomena during scenario evolution. For this demonstration analysis, both reliability assessment techniques are used to analyze an extended station blackout in a pool-type sodium fast reactor (SFR) coupled with a reactor cavity cooling system (RCCS). This work demonstrates the entire process of a passive system reliability analysis, including identification of important parameters and failure metrics, treatment of uncertainties and analysis of results.« less

The a priori SDR Estimation Techniques with Reduced Speech Distortion for Acoustic Echo and Noise Suppression

NASA Astrophysics Data System (ADS)

Thoonsaengngam, Rattapol; Tangsangiumvisai, Nisachon

This paper proposes an enhanced method for estimating the a priori Signal-to-Disturbance Ratio (SDR) to be employed in the Acoustic Echo and Noise Suppression (AENS) system for full-duplex hands-free communications. The proposed a priori SDR estimation technique is modified based upon the Two-Step Noise Reduction (TSNR) algorithm to suppress the background noise while preserving speech spectral components. In addition, a practical approach to determine accurately the Echo Spectrum Variance (ESV) is presented based upon the linear relationship assumption between the power spectrum of far-end speech and acoustic echo signals. The ESV estimation technique is then employed to alleviate the acoustic echo problem. The performance of the AENS system that employs these two proposed estimation techniques is evaluated through the Echo Attenuation (EA), Noise Attenuation (NA), and two speech distortion measures. Simulation results based upon real speech signals guarantee that our improved AENS system is able to mitigate efficiently the problem of acoustic echo and background noise, while preserving the speech quality and speech intelligibility.

Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials.

PubMed

Clark, Catharine H; Aird, Edwin G A; Bolton, Steve; Miles, Elizabeth A; Nisbet, Andrew; Snaith, Julia A D; Thomas, Russell A S; Venables, Karen; Thwaites, David I

2015-01-01

Dosimetry audit plays an important role in the development and safety of radiotherapy. National and large scale audits are able to set, maintain and improve standards, as well as having the potential to identify issues which may cause harm to patients. They can support implementation of complex techniques and can facilitate awareness and understanding of any issues which may exist by benchmarking centres with similar equipment. This review examines the development of dosimetry audit in the UK over the past 30 years, including the involvement of the UK in international audits. A summary of audit results is given, with an overview of methodologies employed and lessons learnt. Recent and forthcoming more complex audits are considered, with a focus on future needs including the arrival of proton therapy in the UK and other advanced techniques such as four-dimensional radiotherapy delivery and verification, stereotactic radiotherapy and MR linear accelerators. The work of the main quality assurance and auditing bodies is discussed, including how they are working together to streamline audit and to ensure that all radiotherapy centres are involved. Undertaking regular external audit motivates centres to modernize and develop techniques and provides assurance, not only that radiotherapy is planned and delivered accurately but also that the patient dose delivered is as prescribed.

Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials

PubMed Central

Aird, Edwin GA; Bolton, Steve; Miles, Elizabeth A; Nisbet, Andrew; Snaith, Julia AD; Thomas, Russell AS; Venables, Karen; Thwaites, David I

2015-01-01

Dosimetry audit plays an important role in the development and safety of radiotherapy. National and large scale audits are able to set, maintain and improve standards, as well as having the potential to identify issues which may cause harm to patients. They can support implementation of complex techniques and can facilitate awareness and understanding of any issues which may exist by benchmarking centres with similar equipment. This review examines the development of dosimetry audit in the UK over the past 30 years, including the involvement of the UK in international audits. A summary of audit results is given, with an overview of methodologies employed and lessons learnt. Recent and forthcoming more complex audits are considered, with a focus on future needs including the arrival of proton therapy in the UK and other advanced techniques such as four-dimensional radiotherapy delivery and verification, stereotactic radiotherapy and MR linear accelerators. The work of the main quality assurance and auditing bodies is discussed, including how they are working together to streamline audit and to ensure that all radiotherapy centres are involved. Undertaking regular external audit motivates centres to modernize and develop techniques and provides assurance, not only that radiotherapy is planned and delivered accurately but also that the patient dose delivered is as prescribed. PMID:26329469

Millimeter-wave imaging of magnetic fusion plasmas: technology innovations advancing physics understanding

NASA Astrophysics Data System (ADS)

Wang, Y.; Tobias, B.; Chang, Y.-T.; Yu, J.-H.; Li, M.; Hu, F.; Chen, M.; Mamidanna, M.; Phan, T.; Pham, A.-V.; Gu, J.; Liu, X.; Zhu, Y.; Domier, C. W.; Shi, L.; Valeo, E.; Kramer, G. J.; Kuwahara, D.; Nagayama, Y.; Mase, A.; Luhmann, N. C., Jr.

2017-07-01

Electron cyclotron emission (ECE) imaging is a passive radiometric technique that measures electron temperature fluctuations; and microwave imaging reflectometry (MIR) is an active radar imaging technique that measures electron density fluctuations. Microwave imaging diagnostic instruments employing these techniques have made important contributions to fusion science and have been adopted at major fusion facilities worldwide including DIII-D, EAST, ASDEX Upgrade, HL-2A, KSTAR, LHD, and J-TEXT. In this paper, we describe the development status of three major technological advancements: custom mm-wave integrated circuits (ICs), digital beamforming (DBF), and synthetic diagnostic modeling (SDM). These have the potential to greatly advance microwave fusion plasma imaging, enabling compact and low-noise transceiver systems with real-time, fast tracking ability to address critical fusion physics issues, including ELM suppression and disruptions in the ITER baseline scenario, naturally ELM-free states such as QH-mode, and energetic particle confinement (i.e. Alfvén eigenmode stability) in high-performance regimes that include steady-state and advanced tokamak scenarios. Furthermore, these systems are fully compatible with today’s most challenging non-inductive heating and current drive systems and capable of operating in harsh environments, making them the ideal approach for diagnosing long-pulse and steady-state tokamaks.

Millimeter-wave imaging of magnetic fusion plasmas: technology innovations advancing physics understanding

DOE PAGES

Wang, Y.; Tobias, B.; Chang, Y. -T.; ...

2017-03-14

Electron cyclotron emission (ECE) imaging is a passive radiometric technique that measures electron temperature fluctuations; and microwave imaging reflectometry (MIR) is an active radar imaging technique that measures electron density fluctuations. The microwave imaging diagnostic instruments employing these techniques have made important contributions to fusion science and have been adopted at major fusion facilities worldwide including DIII-D, EAST, ASDEX Upgrade, HL-2A, KSTAR, LHD, and J-TEXT. In this paper, we describe the development status of three major technological advancements: custom mm-wave integrated circuits (ICs), digital beamforming (DBF), and synthetic diagnostic modeling (SDM). These also have the potential to greatly advance microwavemore » fusion plasma imaging, enabling compact and low-noise transceiver systems with real-time, fast tracking ability to address critical fusion physics issues, including ELM suppression and disruptions in the ITER baseline scenario, naturally ELM-free states such as QH-mode, and energetic particle confinement (i.e. Alfven eigenmode stability) in high-performance regimes that include steady-state and advanced tokamak scenarios. Furthermore, these systems are fully compatible with today's most challenging non-inductive heating and current drive systems and capable of operating in harsh environments, making them the ideal approach for diagnosing long-pulse and steady-state tokamaks.« less

Pre-Employment Skills Training Module for Adult Male Inmates at Riker's Island Correctional Facility.

ERIC Educational Resources Information Center

Johnson, Janice K.

An instructional program called "Passport to a Job" provided prerelease training for inmates at Riker's Island Correctional Facility. The inmates were taught the important steps in preparing for employment; how to identify and cope with discriminatory employment; and how to demonstrate the interview techniques of opening the interview…

Autonomously managed electrical power systems

NASA Technical Reports Server (NTRS)

Callis, Charles P.

1986-01-01

The electric power systems for future spacecraft such as the Space Station will necessarily be more sophisticated and will exhibit more nearly autonomous operation than earlier spacecraft. These new power systems will be more reliable and flexible than their predecessors offering greater utility to the users. Automation approaches implemented on various power system breadboards are investigated. These breadboards include the Hubble Space Telescope power system test bed, the Common Module Power Management and Distribution system breadboard, the Autonomusly Managed Power System (AMPS) breadboard, and the 20 kilohertz power system breadboard. Particular attention is given to the AMPS breadboard. Future plans for these breadboards including the employment of artificial intelligence techniques are addressed.

Time series forecasting using ERNN and QR based on Bayesian model averaging

NASA Astrophysics Data System (ADS)

Pwasong, Augustine; Sathasivam, Saratha

2017-08-01

The Bayesian model averaging technique is a multi-model combination technique. The technique was employed to amalgamate the Elman recurrent neural network (ERNN) technique with the quadratic regression (QR) technique. The amalgamation produced a hybrid technique known as the hybrid ERNN-QR technique. The potentials of forecasting with the hybrid technique are compared with the forecasting capabilities of individual techniques of ERNN and QR. The outcome revealed that the hybrid technique is superior to the individual techniques in the mean square error sense.

Impact of Fatigue in Rheumatic Diseases in the Work Environment: A Qualitative Study.

PubMed

Connolly, Deirdre; Fitzpatrick, Clodagh; O'Toole, Lynn; Doran, Michele; O'Shea, Finbar

2015-10-28

Fatigue is a symptom of arthritis that causes difficulty at work. An improved understanding of this symptom could assist its management in the work environment. The aim of this study was to explore people with rheumatic diseases' experiences of fatigue in work. A qualitative descriptive design was used with semi-structured interviews and a constant comparative method of data analysis. There were 18 participants, the majority of them female with Rheumatoid Arthritis (RA) and working full-time. Three themes were identified: "Impact of fatigue on work performance" with cognition, mood and physical abilities being the main difficulties reported. In the second theme "Disclosure at Work" participants discussed disclosing their disease to employers but reported a lack of understanding of fatigue from colleagues. The final theme "work-based fatigue management strategies" included cognitive strategies and energy management techniques, which were mainly self-taught. In this study, fatigue was reported to impact on many areas of work performance with limited understanding from colleagues and employers. Interventions from health professionals to assist with development of work-related self-management skills are required to assist with symptom management in the work place. Such interventions should include education to employers and colleagues on the nature of fatigue in Rheumatic diseases.

Impact of Fatigue in Rheumatic Diseases in the Work Environment: A Qualitative Study

PubMed Central

Connolly, Deirdre; Fitzpatrick, Clodagh; O’Toole, Lynn; Doran, Michele; O’Shea, Finbar

2015-01-01

Fatigue is a symptom of arthritis that causes difficulty at work. An improved understanding of this symptom could assist its management in the work environment. The aim of this study was to explore people with rheumatic diseases’ experiences of fatigue in work. A qualitative descriptive design was used with semi-structured interviews and a constant comparative method of data analysis. There were 18 participants, the majority of them female with Rheumatoid Arthritis (RA) and working full-time. Three themes were identified: “Impact of fatigue on work performance” with cognition, mood and physical abilities being the main difficulties reported. In the second theme “Disclosure at Work” participants discussed disclosing their disease to employers but reported a lack of understanding of fatigue from colleagues. The final theme “work-based fatigue management strategies” included cognitive strategies and energy management techniques, which were mainly self-taught. In this study, fatigue was reported to impact on many areas of work performance with limited understanding from colleagues and employers. Interventions from health professionals to assist with development of work-related self-management skills are required to assist with symptom management in the work place. Such interventions should include education to employers and colleagues on the nature of fatigue in Rheumatic diseases. PMID:26516896

Seismic Techniques for Subsurface Voids Detection

NASA Astrophysics Data System (ADS)

Gritto, Roland; Korneev, Valeri; Elobaid Elnaiem, Ali; Mohamed, Fathelrahman; Sadooni, Fadhil

2016-04-01

A major hazards in Qatar is the presence of karst, which is ubiquitous throughout the country including depressions, sinkholes, and caves. Causes for the development of karst include faulting and fracturing where fluids find pathways through limestone and dissolve the host rock to form caverns. Of particular concern in rapidly growing metropolitan areas that expand in heretofore unexplored regions are the collapse of such caverns. Because Qatar has seen a recent boom in construction, including the planning and development of complete new sub-sections of metropolitan areas, the development areas need to be investigated for the presence of karst to determine their suitability for the planned project. In this paper, we present the results of a study to demonstrate a variety of seismic techniques to detect the presence of a karst analog in form of a vertical water-collection shaft located on the campus of Qatar University, Doha, Qatar. Seismic waves are well suited for karst detection and characterization. Voids represent high-contrast seismic objects that exhibit strong responses due to incident seismic waves. However, the complex geometry of karst, including shape and size, makes their imaging nontrivial. While karst detection can be reduced to the simple problem of detecting an anomaly, karst characterization can be complicated by the 3D nature of the problem of unknown scale, where irregular surfaces can generate diffracted waves of different kind. In our presentation we employ a variety of seismic techniques to demonstrate the detection and characterization of a vertical water collection shaft analyzing the phase, amplitude and spectral information of seismic waves that have been scattered by the object. We used the reduction in seismic wave amplitudes and the delay in phase arrival times in the geometrical shadow of the vertical shaft to independently detect and locate the object in space. Additionally, we use narrow band-pass filtered data combining two orthogonal transmission surveys to detect and locate the object. Furthermore, we showed that ambient noise recordings may generate data with sufficient signal-to-noise ratio to successfully detect and locate subsurface voids. Being able to use ambient noise recordings would eliminate the need to employ active seismic sources that are time consuming and more expensive to operate.

Comparison of Metal-Backed Free-Space and Open-Ended Coaxial Probe Techniques for the Dielectric Characterization of Aeronautical Composites †

PubMed Central

López-Rodríguez, Patricia; Escot-Bocanegra, David; Poyatos-Martínez, David; Weinmann, Frank

2016-01-01

The trend in the last few decades is that current unmanned aerial vehicles are completely made of composite materials rather than metallic, such as carbon-fiber or fiberglass composites. From the electromagnetic point of view, this fact forces engineers and scientists to assess how these materials may affect their radar response or their electronics in terms of electromagnetic compatibility. In order to evaluate this, electromagnetic characterization of different composite materials has become a need. Several techniques exist to perform this characterization, all of them based on the utilization of different sensors for measuring different parameters. In this paper, an implementation of the metal-backed free-space technique, based on the employment of antenna probes, is utilized for the characterization of composite materials that belong to an actual drone. Their extracted properties are compared with those given by a commercial solution, an open-ended coaxial probe (OECP). The discrepancies found between both techniques along with a further evaluation of the methodologies, including measurements with a split-cavity resonator, conclude that the implemented free-space technique provides more reliable results for this kind of composites than the OECP technique. PMID:27347966

A ground-based technique for millimeter wave spectroscopic observations of stratospheric trace constituents

NASA Technical Reports Server (NTRS)

Parrish, A.; Dezafra, R. L.; Solomon, P. M.; Barrett, J. W.

1988-01-01

Recent concern over possible long term stratospheric changes caused by the introduction of man-made compounds has increased the need for instrumentation that can accurately measure stratospheric minor constituents. The technique of radio spectroscopy at millimeter wavelengths was first used to observe rotational transitions of stratospheric ozone nearly two decades ago, but has not been highly developed until recently. A ground-based observing technique is reported which employs a millimeter-wave superheterodyne receiver and multichannel filter spectrometer for measurements of stratospheric constituents that have peak volume mixing ratios that are less than 10 to the -9th, more than 3 orders of magnitude less than that for ozone. The technique is used for an extensive program of observations of stratospheric chlorine monoxide and also for observations of other stratospheric trace gases such as (O-16)3, vibrationally excited (O-16)3, (O-18)2(O-16), N2O, HO2, and HCN. In the present paper, analysis of the observing technique is given, including the method of calibration and analysis of sources of error. The technique is found to be a reliable means of observing and monitoring important stratospheric trace constituents.

Discrete Wavelet Transform for Fault Locations in Underground Distribution System

NASA Astrophysics Data System (ADS)

Apisit, C.; Ngaopitakkul, A.

2010-10-01

In this paper, a technique for detecting faults in underground distribution system is presented. Discrete Wavelet Transform (DWT) based on traveling wave is employed in order to detect the high frequency components and to identify fault locations in the underground distribution system. The first peak time obtained from the faulty bus is employed for calculating the distance of fault from sending end. The validity of the proposed technique is tested with various fault inception angles, fault locations and faulty phases. The result is found that the proposed technique provides satisfactory result and will be very useful in the development of power systems protection scheme.

Bidirectional and simultaneous FTTX/Ethernet services using RSOA based remodulation and polarization multiplexing technique

NASA Astrophysics Data System (ADS)

Das, Anindya S.; Patra, Ardhendu S.

2015-08-01

A bidirectional and simultaneous transmission of Ethernet, FTTX services through single optical carrier wavelength employing polarization multiplexing technique in the transmitter end and the user end. 10 Gbps and 2.5 Gbps datarates are transmitted over 50 km single mode fiber employing POLMUX technique at OLT and ONU to provide Ethernet and FTTX services concurrently to the user. Reflective semiconductor optical amplifier is used to reuse and remodulate the downlink signal to uplink transmission. The upstream and the downstream transmission performances are observed by the bit error rate values and the eye diagrams obtained by the BER analyzer.

Study of Belousov—Zhabotinsky oscillators in water—acetonitrile medium employing EMF and EPR techniques with o-vanillin, p-vanillin and adrenaline as substrates

NASA Astrophysics Data System (ADS)

Lalitha, P. V.; Ramaswamy, R.; Ramakrishnan, Geetha; Rao, P. Sambasiva

1994-12-01

The oscillatory behaviour of three substrates, ortho-vanillin, para-vanillin and adrenaline, in mixed media (water plus 20% acetonitrile) has been investigated using EPR and EMF techniques. All these substrates exhibit two types of oscillation involving Br 2/Br - and Mn(III)/Mn(II) redox couples. From the oscillatory characteristics (total time, number of oscillations and time per oscillation) obtained by employing these techniques, the reactivities of the vanillins have been correlated. The Field—Koros—Noyes mechanism, suggested for catalysed systems in pure aqueous medium, is established to be applicable even in mixed media.

Lagrangian Modeling of Evaporating Sprays at Diesel Engine Conditions: Effects of Multi-Hole Injector Nozzles With JP-8 Surrogates

DTIC Science & Technology

2014-05-01

solver to treat the spray process. An Adaptive Mesh Refinement (AMR) and fixed embedding technique is employed to capture the gas - liquid interface with...Adaptive Mesh Refinement (AMR) and fixed embedding technique is employed to capture the gas - liquid interface with high fidelity while keeping the cell...in single and multi-hole nozzle configurations. The models were added to the present CONVERGE liquid fuel database and validated extensively

The value of job analysis, job description and performance.

PubMed

Wolfe, M N; Coggins, S

1997-01-01

All companies, regardless of size, are faced with the same employment concerns. Efficient personnel management requires the use of three human resource techniques--job analysis, job description and performance appraisal. These techniques and tools are not for large practices only. Small groups can obtain the same benefits by employing these performance control measures. Job analysis allows for the development of a compensation system. Job descriptions summarize the most important duties. Performance appraisals help reward outstanding work.

Automated design of genomic Southern blot probes

PubMed Central

2010-01-01

Background Sothern blotting is a DNA analysis technique that has found widespread application in molecular biology. It has been used for gene discovery and mapping and has diagnostic and forensic applications, including mutation detection in patient samples and DNA fingerprinting in criminal investigations. Southern blotting has been employed as the definitive method for detecting transgene integration, and successful homologous recombination in gene targeting experiments. The technique employs a labeled DNA probe to detect a specific DNA sequence in a complex DNA sample that has been separated by restriction-digest and gel electrophoresis. Critically for the technique to succeed the probe must be unique to the target locus so as not to cross-hybridize to other endogenous DNA within the sample. Investigators routinely employ a manual approach to probe design. A genome browser is used to extract DNA sequence from the locus of interest, which is searched against the target genome using a BLAST-like tool. Ideally a single perfect match is obtained to the target, with little cross-reactivity caused by homologous DNA sequence present in the genome and/or repetitive and low-complexity elements in the candidate probe. This is a labor intensive process often requiring several attempts to find a suitable probe for laboratory testing. Results We have written an informatic pipeline to automatically design genomic Sothern blot probes that specifically attempts to optimize the resultant probe, employing a brute-force strategy of generating many candidate probes of acceptable length in the user-specified design window, searching all against the target genome, then scoring and ranking the candidates by uniqueness and repetitive DNA element content. Using these in silico measures we can automatically design probes that we predict to perform as well, or better, than our previous manual designs, while considerably reducing design time. We went on to experimentally validate a number of these automated designs by Southern blotting. The majority of probes we tested performed well confirming our in silico prediction methodology and the general usefulness of the software for automated genomic Southern probe design. Conclusions Software and supplementary information are freely available at: http://www.genes2cognition.org/software/southern_blot PMID:20113467

Nano-based systems for oil spills control and cleanup.

PubMed

Avila, Antonio F; Munhoz, Viviane C; de Oliveira, Aline M; Santos, Mayara C G; Lacerda, Glenda R B S; Gonçalves, Camila P

2014-05-15

This paper reports the development of superhydrophobic nanocomposite systems which are also oleophilic. As hydrophobicity is based on low energy surface and surface roughness, the electrospinning technique was selected as the manufacturing technique. N,N' dimethylformamide (DMF) was employed as the polystyrene (PS) solvent. The "Tea-bag" (T-B) nanocomposite system is based on exfoliated graphite surrounded by PS superhydrophobic membranes. The T-B systems were tested regarding its adsorption and absorption rates. To test these properties, it was employed three different water/oil emulsions, i.e., new and used motor oil, which have physical properties (viscosity and specific gravity) similar to heavy crude oil extracted in Brazil, and vacuum pump oil (which does not form oil/water emulsion). It was observed that oil adsorption rate is dependent on oil surface tension, while the absorption rate is mainly dependent on membrane/exfoliated graphite surface area. Experimental data show that oil absorption rates ranged between 2.5g/g and 40g/g, while the adsorption rate oscillated from 0.32g/g/min to 0.80g/g/min. Furthermore, T-B systems were tested as containment barriers and sorbent materials with good results including its recyclability. Copyright © 2014 Elsevier B.V. All rights reserved.

Tungsten devices in analytical atomic spectrometry

NASA Astrophysics Data System (ADS)

Hou, Xiandeng; Jones, Bradley T.

2002-04-01

Tungsten devices have been employed in analytical atomic spectrometry for approximately 30 years. Most of these atomizers can be electrically heated up to 3000 °C at very high heating rates, with a simple power supply. Usually, a tungsten device is employed in one of two modes: as an electrothermal atomizer with which the sample vapor is probed directly, or as an electrothermal vaporizer, which produces a sample aerosol that is then carried to a separate atomizer for analysis. Tungsten devices may take various physical shapes: tubes, cups, boats, ribbons, wires, filaments, coils and loops. Most of these orientations have been applied to many analytical techniques, such as atomic absorption spectrometry, atomic emission spectrometry, atomic fluorescence spectrometry, laser excited atomic fluorescence spectrometry, metastable transfer emission spectroscopy, inductively coupled plasma optical emission spectrometry, inductively coupled plasma mass spectrometry and microwave plasma atomic spectrometry. The analytical figures of merit and the practical applications reported for these techniques are reviewed. Atomization mechanisms reported for tungsten atomizers are also briefly summarized. In addition, less common applications of tungsten devices are discussed, including analyte preconcentration by adsorption or electrodeposition and electrothermal separation of analytes prior to analysis. Tungsten atomization devices continue to provide simple, versatile alternatives for analytical atomic spectrometry.

Nonlinear adaptive control of grid-connected three-phase inverters for renewable energy applications

NASA Astrophysics Data System (ADS)

Mahdian-Dehkordi, N.; Namvar, M.; Karimi, H.; Piya, P.; Karimi-Ghartemani, M.

2017-01-01

Distributed generation (DG) units are often interfaced to the main grid using power electronic converters including voltage-source converters (VSCs). A VSC offers dc/ac power conversion, high controllability, and fast dynamic response. Because of nonlinearities, uncertainties, and system parameters' changes involved in the nature of a grid-connected renewable DG system, conventional linear control methods cannot completely and efficiently address all control objectives. In this paper, a nonlinear adaptive control scheme based on adaptive backstepping strategy is presented to control the operation of a grid-connected renewable DG unit. As compared to the popular vector control technique, the proposed controller offers smoother transient responses, and lower level of current distortions. The Lyapunov approach is used to establish global asymptotic stability of the proposed control system. Linearisation technique is employed to develop guidelines for parameters tuning of the controller. Extensive time-domain digital simulations are performed and presented to verify the performance of the proposed controller when employed in a VSC to control the operation of a two-stage DG unit and also that of a single-stage solar photovoltaic system. Desirable and superior performance of the proposed controller is observed.

Inserting ex vivo fluorescence confocal microscopy perioperatively in Mohs micrographic surgery expedites bedside assessment of excision margins in recurrent basal cell carcinoma.

PubMed

Longo, Caterina; Ragazzi, Moira; Castagnetti, Fabio; Gardini, Stefano; Palmieri, Tamara; Lallas, Aimilios; Moscarella, Elvira; Piana, Simonetta; Pellacani, Giovanni; Zalaudek, Iris; Argenziano, Giuseppe

2013-01-01

Mohs micrographic surgery can be employed in recurrent basal cell carcinoma, although it is a time-consuming technique. Recently, ex vivo fluorescence confocal microscopy (FCM) has been employed to obtain a fast assessment of tumor margins at the bedside. In our case we successfully employed ex vivo FCM to assess the tumor margins and we treated the persistent tumor with intensity-modulated radiation therapy. Our case demonstrates that a multidisciplinary approach is very efficient in managing complex and recurrent tumors and highlights the benefits of FCM as a new technique that can be used in the surgical theater to speed up the entire procedure.

Analytical methods for the assessment of endocrine disrupting chemical exposure during human fetal and lactation stages: a review.

PubMed

Jiménez-Díaz, I; Vela-Soria, F; Rodríguez-Gómez, R; Zafra-Gómez, A; Ballesteros, O; Navalón, A

2015-09-10

In the present work, a review of the analytical methods developed in the last 15 years for the determination of endocrine disrupting chemicals (EDCs) in human samples related with children, including placenta, cord blood, amniotic fluid, maternal blood, maternal urine and breast milk, is proposed. Children are highly vulnerable to toxic chemicals in the environment. Among these environmental contaminants to which children are at risk of exposure are EDCs -substances able to alter the normal hormone function of wildlife and humans-. The work focuses mainly on sample preparation and instrumental techniques used for the detection and quantification of the analytes. The sample preparation techniques include, not only liquid-liquid extraction (LLE) and solid-phase extraction (SPE), but also modern microextraction techniques such as extraction with molecular imprinted polymers (MIPs), stir-bar sorptive extraction (SBSE), hollow-fiber liquid-phase microextraction (HF-LPME), dispersive liquid-liquid microextraction (DLLME), matrix solid phase dispersion (MSPD) or ultrasound-assisted extraction (UAE), which are becoming alternatives in the analysis of human samples. Most studies focus on minimizing the number of steps and using the lowest solvent amounts in the sample treatment. The usual instrumental techniques employed include liquid chromatography (LC), gas chromatography (GC) mainly coupled to tandem mass spectrometry. Multiresidue methods are being developed for the determination of several families of EDCs with one extraction step and limited sample preparation. Copyright © 2015 Elsevier B.V. All rights reserved.

Non-invasive neuroimaging using near-infrared light

NASA Technical Reports Server (NTRS)

Strangman, Gary; Boas, David A.; Sutton, Jeffrey P.

2002-01-01

This article reviews diffuse optical brain imaging, a technique that employs near-infrared light to non-invasively probe the brain for changes in parameters relating to brain function. We describe the general methodology, including types of measurements and instrumentation (including the tradeoffs inherent in the various instrument components), and the basic theory required to interpret the recorded data. A brief review of diffuse optical applications is included, with an emphasis on research that has been done with psychiatric populations. Finally, we discuss some practical issues and limitations that are relevant when conducting diffuse optical experiments. We find that, while diffuse optics can provide substantial advantages to the psychiatric researcher relative to the alternative brain imaging methods, the method remains substantially underutilized in this field.

Remote sensing based approach for monitoring urban growth in Mexico city, Mexico: A case study

NASA Astrophysics Data System (ADS)

Obade, Vincent

The world is experiencing a rapid rate of urban expansion, largely contributed by the population growth. Other factors supporting urban growth include the improved efficiency in the transportation sector and increasing dependence on cars as a means of transport. The problems attributed to the urban growth include: depletion of energy resources, water and air pollution; loss of landscapes and wildlife, loss of agricultural land, inadequate social security and lack of employment or underemployment. Aerial photography is one of the popular techniques for analyzing, planning and minimizing urbanization related problems. However, with the advances in space technology, satellite remote sensing is increasingly being utilized in the analysis and planning of the urban environment. This article outlines the strengths and limitations of potential remote sensing techniques for monitoring urban growth. The selected methods include: Principal component analysis, Maximum likelihood classification and "decision tree". The results indicate that the "classification tree" approach is the most promising for monitoring urban change, given the improved accuracy and smooth transition between the various land cover classes

Constructing a nurse appraisal form: A Delphi technique study

PubMed Central

Zaghloul, Ashraf Ahmad Zaher; AlSokair, May Kosay

2008-01-01

Objective The study was conducted with the aim to construct a unified nurse appraisal format to be used at hospitals performing under different healthcare organizations in the Eastern Province in the Kingdom of Saudi Arabia. Methodology The study included hospitals representing different healthcare organizations within the Eastern Province. The target population included Hospital head nurses and nurse supervisors and the snowball sampling technique was employed to select the panel subjects. Results The final draft resulted into the agreed upon performance dimensions which included namely; quality standards, work habits, supervision/leadership, staff relations and interpersonal skills, attendance and punctuality, problem solving, oral communication, productivity results, coordination, innovation, record keeping. Conclusion Nurse managers have to continuously assess competence of practicing nurses to assure qualified and safe patient care. A nurse appraisal form was constructed concurrently with this study results and was proposed to be used at all Eastern Region hospitals. This study is considered an initial step for further efforts and studies to be conducted to reach both national and international nursing appraisal dimensions and unify them for the sake of best health promotion. PMID:21197327

Characterization of Contrast Agent Microbubbles for Ultrasound Imaging and Therapy Research.

PubMed

Mulvana, Helen; Browning, Richard J; Luan, Ying; de Jong, Nico; Tang, Meng-Xing; Eckersley, Robert J; Stride, Eleanor

2017-01-01

The high efficiency with which gas microbubbles can scatter ultrasound compared with the surrounding blood pool or tissues has led to their widespread employment as contrast agents in ultrasound imaging. In recent years, their applications have been extended to include super-resolution imaging and the stimulation of localized bio-effects for therapy. The growing exploitation of contrast agents in ultrasound and in particular these recent developments have amplified the need to characterize and fully understand microbubble behavior. The aim in doing so is to more fully exploit their utility for both diagnostic imaging and potential future therapeutic applications. This paper presents the key characteristics of microbubbles that determine their efficacy in diagnostic and therapeutic applications and the corresponding techniques for their measurement. In each case, we have presented information regarding the methods available and their respective strengths and limitations, with the aim of presenting information relevant to the selection of appropriate characterization methods. First, we examine methods for determining the physical properties of microbubble suspensions and then techniques for acoustic characterization of both suspensions and single microbubbles. The next section covers characterization of microbubbles as therapeutic agents, including as drug carriers for which detailed understanding of their surface characteristics and drug loading capacity is required. Finally, we discuss the attempts that have been made to allow comparison across the methods employed by various groups to characterize and describe their microbubble suspensions and promote wider discussion and comparison of microbubble behavior.

Experiment K-7-18: Effects of Spaceflight in the Muscle Adductor Longus of Rats Flown in the Soviet Biosatellite Cosmos 2044. Part 1; A Study Employing Neural Cell Adhesion Molecules (N-CAM) Immunocytochemistry and Conventional Morphological Techniques (Light and Electron Microscopy)

NASA Technical Reports Server (NTRS)

Daunton, N. G.; DAmelio, F.; Wu, L.; Ilyina-Kakueva, E. I.; Krasnov, I. B.; Hyde, T. M.; Sigworth, S. K.

1994-01-01

The effects of spaceflight upon the 'slow' muscle adductor longus was examined in rats flown in the Soviet Biosatellite COSMOS 2044. Three groups - synchronous, vivarium and basal served as controls. The techniques employed included standard methods for light microscopy, N-CAM immunocytochemistry and electron microscopy. Light microscopic observations revealed myofiber atrophy, contraction bands and segmental necrosis accompanied by cellular infiltrates composed of macrophages, leucocytes and mononuclear cells. N-CAM immunoreactivity was seen (N-CAM-IR) on the myofiber surface, satellite cells and in regenerating myofibers reminiscent of myotubes. Ultrastructural alterations included Z band streaming, disorganization of myofibrillar architecture, sarcoplasmic degradation, extensive segmental necrosis with preservation of the basement membrane, degenerative phenomena of the capillary endothelium and cellular invasion of necrotic areas. Regenerating myofibers were identified by the presence of increased amounts of ribosomal aggregates and chains of polyribosomes associated with myofilaments that displayed varied distributive patterns. The principal electron microscopic changes of the neuromuscular junctions consisted of a decrease or absence of synaptic vesicles, degeneration of axon terminals, increased number of microtubules, vacant axonal spaces and axonal sprouting. The present observations indicate that major alterations such as myofibrillar disruption and necrosis, muscle regeneration and denervation and synaptic remodeling at the level of the neuromuscular junction may take place during spaceflight.

A case study on the application of isotope ratio mass spectrometry (IRMS) in determining the provenance of a rock used in an alleged nickel switching incident.

PubMed

Roelofse, F; Horstmann, U E

2008-01-15

The application of isotope ratio mass spectrometry (IRMS) in forensic science to establish the provenance of a range of questioned substances including soils, drugs, explosives, currency, ivory and rhino horn has been widely documented. The present study wishes to highlight the applicability of IRMS and specifically stable carbon IRMS in determining the provenance of a carbonate rock that was switched for nickel metal exported from South Africa to Israel. The technique employed effectively argued against a South African origin for the rock whilst simultaneously supporting an Israeli origin, enabling investigators to focus their attention accordingly. The study represents the first documented instance known to the authors where IRMS has been employed in the forensic geo-location of a rock.

Linking the Pilot Structural Model and Pilot Workload

NASA Technical Reports Server (NTRS)

Bachelder, Edward; Hess, Ronald; Aponso, Bimal; Godfroy-Cooper, Martine

2018-01-01

Behavioral models are developed that closely reproduced pulsive control response of two pilots using markedly different control techniques while conducting a tracking task. An intriguing find was that the pilots appeared to: 1) produce a continuous, internally-generated stick signal that they integrated in time; 2) integrate the actual stick position; and 3) compare the two integrations to either issue or cease a pulse command. This suggests that the pilots utilized kinesthetic feedback in order to sense and integrate stick position, supporting the hypothesis that pilots can access and employ the proprioceptive inner feedback loop proposed by Hess's pilot Structural Model. A Pilot Cost Index was developed, whose elements include estimated workload, performance, and the degree to which the pilot employs kinesthetic feedback. Preliminary results suggest that a pilot's operating point (parameter values) may be based on control style and index minimization.

Benefit from NASA

NASA Image and Video Library

2001-09-01

The high-tech art of digital signal processing (DSP) was pioneered at NASA's Jet Propulsion Laboratory (JPL) in the mid-1960s for use in the Apollo Lunar Landing Program. Designed to computer enhance pictures of the Moon, this technology became the basis for the Landsat Earth resources satellites and subsequently has been incorporated into a broad range of Earthbound medical and diagnostic tools. DSP is employed in advanced body imaging techniques including Computer-Aided Tomography, also known as CT and CATScan, and Magnetic Resonance Imaging (MRI). CT images are collected by irradiating a thin slice of the body with a fan-shaped x-ray beam from a number of directions around the body's perimeter. A tomographic (slice-like) picture is reconstructed from these multiple views by a computer. MRI employs a magnetic field and radio waves, rather than x-rays, to create images.

The effect of hospital control strategies on physician satisfaction and physician-hospital conflict.

PubMed Central

Burns, L R; Andersen, R M; Shortell, S M

1990-01-01

This article examines several strategies that hospitals use to control their medical staffs. Such strategies include placing physicians on salary, developing exclusive hospital affiliations with physicians, and involving physicians in decision-making bodies. Using regression techniques, we investigate which hospitals are more likely to utilize these strategies and whether such strategies are effective in promoting physician-hospital integration. Contrary to our expectations, corporate hospital structures (e.g., for-profit hospitals, membership in multihospital systems) generally do not employ these strategies more often and oftentimes employ them less. There is also little evidence that control strategies are effective levers for increasing physician satisfaction or decreasing physician-hospital conflict. We suggest that control strategies are useful for purposes other than promoting physician-hospital integration. Finally, hospital ownership appears to exert the biggest effect on physician satisfaction and conflict. PMID:2380074

An extensive ab initio study of the structures, vibrational spectra, quadratic force fields, and relative energetics of three isomers of Cl2O2

NASA Technical Reports Server (NTRS)

Lee, Timothy J.; Rohlfing, Celeste MCM.; Rice, Julia E.

1992-01-01

Quantum mechanical computational methods are employed for an ab initio investigation of: (1) the molecular properties of the lowest isomers of the ClO dimer; and (2) predicted molecular and thermochemical properties. Techniques employed include electron correlation and particularly singles and doubles coupled-cluster (CCSD) theory with or without perturbational estimates of the effects of connected triple excitations. The isomers ClOClO and ClClO2 are found to have higher energies than the ClOOCl isomer, and the theoretical vibrational frequencies of the isomers are well correlated with experimental data. Experimental values of the heat of formation for the isomers are also compared with calculations based on an isodesmic reaction with Cl2O, H2O, and HOOH.

Hybrid label-free multiphoton and optoacoustic microscopy (MPOM)

NASA Astrophysics Data System (ADS)

Soliman, Dominik; Tserevelakis, George J.; Omar, Murad; Ntziachristos, Vasilis

2015-07-01

Many biological applications require a simultaneous observation of different anatomical features. However, unless potentially harmful staining of the specimens is employed, individual microscopy techniques do generally not provide multi-contrast capabilities. We present a hybrid microscope integrating optoacoustic microscopy and multiphoton microscopy, including second-harmonic generation, into a single device. This combined multiphoton and optoacoustic microscope (MPOM) offers visualization of a broad range of structures by employing different contrast mechanisms and at the same time enables pure label-free imaging of biological systems. We investigate the relative performance of the two microscopy modalities and demonstrate their multi-contrast abilities through the label-free imaging of a zebrafish larva ex vivo, simultaneously visualizing muscles and pigments. This hybrid microscopy application bears great potential for developmental biology studies, enabling more comprehensive information to be obtained from biological specimens without the necessity of staining.

Enhancing Individual Employability: The Perspective of Engineering Graduates

ERIC Educational Resources Information Center

Nilsson, Staffan

2010-01-01

Purpose: Employability includes the ability to find employment and remain employed. Employability includes both hard and soft skills, including formal and actual competence, interpersonal skills, and personal characteristics. This paper aims to focus on illuminating perceptions engineering graduates have regarding employability. More specifically,…

Investigating the Similarities and Differences between Practitioners of Second and Third Wave Cognitive-Behavioral Therapies

PubMed Central

Brown, Lily A.; Gaudiano, Brandon A.; Miller, Ivan W.

2013-01-01

There has been much discussion in the literature recently regarding the conceptual and techniual differences between so-called second (e.g., Beckian cognitive therapy) and third “wave” (e.g., acceptance and commitment therapy) behavior therapies. Previous research has not addressed the potential similarities and differences among the practitioners of these types of approaches. The current study examined possible differences in the characteristics of second wave (n=55) and third wave cognitive-behavioral therapists (n=33) using an internet-based survey. There were differences found at the technique level between the two groups. As expected, third wave therapists reported greater use of mindfulness/acceptance techniques. Also, third wave therapists reported greater use of exposure techniques and second wave therapists reported greater use of cognitive restructuring and relaxation techniques. In general, third wave clinicians were more eclectic at the technique level, and demonstrated significantly greater use of family systems techniques, existential/humanistic techniques, and the total number of techniques used. No significant differences were found on the attitudinal measures administered, including reliance on an intuitive thinking style, acceptance of complementary and alternative therapies and related health beliefs, or most attitudes toward evidence-based practices. We did not identify many differences between second wave and third wave therapists other than in terms of the techniques they employ. The clinical and research implications for these findings are discussed. PMID:21324946

Application of satellite data and LARS's data processing techniques to mapping vegetation of the Dismal Swamp. M.S. Thesis - Old Dominion Univ.

NASA Technical Reports Server (NTRS)

Messmore, J. A.

1976-01-01

The feasibility of using digital satellite imagery and automatic data processing techniques as a means of mapping swamp forest vegetation was considered, using multispectral scanner data acquired by the LANDSAT-1 satellite. The site for this investigation was the Dismal Swamp, a 210,000 acre swamp forest located south of Suffolk, Va. on the Virginia-North Carolina border. Two basic classification strategies were employed. The initial classification utilized unsupervised techniques which produced a map of the swamp indicating the distribution of thirteen forest spectral classes. These classes were later combined into three informational categories: Atlantic white cedar (Chamaecyparis thyoides), Loblolly pine (Pinus taeda), and deciduous forest. The subsequent classification employed supervised techniques which mapped Atlantic white cedar, Loblolly pine, deciduous forest, water and agriculture within the study site. A classification accuracy of 82.5% was produced by unsupervised techniques compared with 89% accuracy using supervised techniques.

Stretching of Single Polymer Chains Using the Atomic Force Microscope

NASA Astrophysics Data System (ADS)

Ortiz, C.; van der Vegte, E. W.; van Swieten, E.; Robillard, G. T.; Hadziioannou, G.

1998-03-01

A variety of macroscopic phenomenon involve "nanoscale" polymer deformation including rubber elasticity, shear yielding, strain hardening, stress relaxation, fracture, and flow. With the advent of new and improved experimental techniques, such as the atomic force microscope (AFM), the probing of physical properties of polymers has reached finer and finer scales. The development of mixed self-assembling monolayer techniques and the chemical functionalization of AFM probe tips has allowed for mechanical experiments on single polymer chains of molecular dimensions. In our experiments, mixed monolayers are prepared in which end-functionalized, flexible polymer chains of thiol-terminated poly(methacrylic acid) are covalently bonded, isolated, and randomly distributed on gold substrates. The coils are then imaged, tethered to a gold-coated AFM tip, and stretched between the tip and the substrate in a conventional force / distance experiment. An increase in the attractive force due to entropic, elastic resistance to stretching, as well as fracture of the polymer chain is observed. The effect of chain stiffness, topological constraints, strain rate, mechanical hysteresis, and stress relaxation were investigated. Force modulation techniques were also employed in order to image the viscoelastic character of the polymer chains. Parallel work includes similar studies of biological systems such as wheat gluten proteins and polypeptides.

Recent Advances in Bioprinting and Applications for Biosensing

PubMed Central

Dias, Andrew D.; Kingsley, David M.; Corr, David T.

2014-01-01

Future biosensing applications will require high performance, including real-time monitoring of physiological events, incorporation of biosensors into feedback-based devices, detection of toxins, and advanced diagnostics. Such functionality will necessitate biosensors with increased sensitivity, specificity, and throughput, as well as the ability to simultaneously detect multiple analytes. While these demands have yet to be fully realized, recent advances in biofabrication may allow sensors to achieve the high spatial sensitivity required, and bring us closer to achieving devices with these capabilities. To this end, we review recent advances in biofabrication techniques that may enable cutting-edge biosensors. In particular, we focus on bioprinting techniques (e.g., microcontact printing, inkjet printing, and laser direct-write) that may prove pivotal to biosensor fabrication and scaling. Recent biosensors have employed these fabrication techniques with success, and further development may enable higher performance, including multiplexing multiple analytes or cell types within a single biosensor. We also review recent advances in 3D bioprinting, and explore their potential to create biosensors with live cells encapsulated in 3D microenvironments. Such advances in biofabrication will expand biosensor utility and availability, with impact realized in many interdisciplinary fields, as well as in the clinic. PMID:25587413

Conformational analysis of misfolded protein aggregation by FRET and live-cell imaging techniques.

PubMed

Kitamura, Akira; Nagata, Kazuhiro; Kinjo, Masataka

2015-03-16

Cellular homeostasis is maintained by several types of protein machinery, including molecular chaperones and proteolysis systems. Dysregulation of the proteome disrupts homeostasis in cells, tissues, and the organism as a whole, and has been hypothesized to cause neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD). A hallmark of neurodegenerative disorders is formation of ubiquitin-positive inclusion bodies in neurons, suggesting that the aggregation process of misfolded proteins changes during disease progression. Hence, high-throughput determination of soluble oligomers during the aggregation process, as well as the conformation of sequestered proteins in inclusion bodies, is essential for elucidation of physiological regulation mechanism and drug discovery in this field. To elucidate the interaction, accumulation, and conformation of aggregation-prone proteins, in situ spectroscopic imaging techniques, such as Förster/fluorescence resonance energy transfer (FRET), fluorescence correlation spectroscopy (FCS), and bimolecular fluorescence complementation (BiFC) have been employed. Here, we summarize recent reports in which these techniques were applied to the analysis of aggregation-prone proteins (in particular their dimerization, interactions, and conformational changes), and describe several fluorescent indicators used for real-time observation of physiological states related to proteostasis.

Fractional-N phase-locked loop for split and direct automatic frequency control in A-GPS

NASA Astrophysics Data System (ADS)

Park, Chester Sungchung; Park, Sungkyung

2018-07-01

A low-power mixed-signal phase-locked loop (PLL) is modelled and designed for the DigRF interface between the RF chip and the modem chip. An assisted-GPS or A-GPS multi-standard system includes the DigRF interface and uses the split automatic frequency control (AFC) technique. The PLL circuitry uses the direct AFC technique and is based on the fractional-N architecture using a digital delta-sigma modulator along with a digital counter, fulfilling simple ultra-high-resolution AFC with robust digital circuitry and its timing. Relative to the output frequency, the measured AFC resolution or accuracy is <5 parts per billion (ppb) or on the order of a Hertz. The cycle-to-cycle rms jitter is <6 ps and the typical settling time is <30 μs. A spur reduction technique is adopted and implemented as well, demonstrating spur reduction without employing dithering. The proposed PLL includes a low-leakage phase-frequency detector, a low-drop-out regulator, power-on-reset circuitry and precharge circuitry. The PLL is implemented in a 90-nm CMOS process technology with 1.2 V single supply. The overall PLL draws about 1.1 mA from the supply.

Employment, work hours and weight gain among middle-aged women.

PubMed

Au, N; Hauck, K; Hollingsworth, B

2013-05-01

To investigate the influence of employment and work hours on weight gain and weight loss among middle-aged women. Quantile regression techniques were used to estimate the influence of employment and hours worked on percentage weight change over 2 years across the entire distribution of weight change in a cohort of middle-aged women. A range of controls was included in the models to isolate the effect of work status. A total of 9276 women aged 45-50 years at baseline who were present in both the 1996 and 1998 surveys of the Australian Longitudinal Study of Women's Health. The women were a representative sample of the Australian population. Being out of the labour force or unemployed was associated with lower weight gain and higher weight loss than being employed. The association was stronger at low to moderate levels of weight gain. Among employed women, working regular (35-40), long (41-48) or very long (49+) hours was associated with increasingly higher levels of weight gain compared with working part-time hours. The association was stronger for women with greater weight gain overall. The association between unemployment and weight change became insignificant when health status was controlled for. Employment was associated with more weight gain and less weight loss. Among the employed, working longer hours was associated with more weight gain, especially at the higher levels of weight gain where the health consequences are more serious. These findings suggest that as women work longer hours they are more likely to make lifestyle choices that are associated with weight gain.

Quantitative analysis of ribosome–mRNA complexes at different translation stages

PubMed Central

Shirokikh, Nikolay E.; Alkalaeva, Elena Z.; Vassilenko, Konstantin S.; Afonina, Zhanna A.; Alekhina, Olga M.; Kisselev, Lev L.; Spirin, Alexander S.

2010-01-01

Inhibition of primer extension by ribosome–mRNA complexes (toeprinting) is a proven and powerful technique for studying mechanisms of mRNA translation. Here we have assayed an advanced toeprinting approach that employs fluorescently labeled DNA primers, followed by capillary electrophoresis utilizing standard instruments for sequencing and fragment analysis. We demonstrate that this improved technique is not merely fast and cost-effective, but also brings the primer extension inhibition method up to the next level. The electrophoretic pattern of the primer extension reaction can be characterized with a precision unattainable by the common toeprint analysis utilizing radioactive isotopes. This method allows us to detect and quantify stable ribosomal complexes at all stages of translation, including initiation, elongation and termination, generated during the complete translation process in both the in vitro reconstituted translation system and the cell lysate. We also point out the unique advantages of this new methodology, including the ability to assay sites of the ribosomal complex assembly on several mRNA species in the same reaction mixture. PMID:19910372

Scientific and clinical support for the use of dehydrated amniotic membrane in wound management.

PubMed

Fetterolf, Donald E; Snyder, Robert J

2012-10-01

 Amniotic membrane has been employed in the treatment of wounds for almost 100 years, beginning with early application of natural amniotic membrane obtained from labor and delivery to various types of burns and wounds. Amniotic membrane is rich in collagen and various growth factors that support the healing process to both improve wound closure and reduce scar formation. Unique properties of the material include the lack of immunologic markers, conferring an "immune privileged" status on the allografts; antibacterial properties; and the ability to reduce pain on application. The resurgence of interest in the use of amniotic membrane in a number of applications, including wound treatment, has occurred following improved techniques for preserving the natural membrane. Recently, techniques have been developed to dehydrate the material while preserving many of these wound-healing attributes, to produce a temperature-stable allograft. Future research will continue to yield more information on the unique properties of the amniotic membrane allografts. .

Jumping, Rotating, and Flapping: The Atomic-Scale Motion of Thiophene on Cu(111).

PubMed

Lechner, Barbara A J; Sacchi, Marco; Jardine, Andrew P; Hedgeland, Holly; Allison, William; Ellis, John; Jenkins, Stephen J; Dastoor, Paul C; Hinch, B J

2013-06-06

Self-assembled monolayers of sulfur-containing heterocycles and linear oligomers containing thiophene groups have been widely employed in organic electronic applications. Here, we investigate the dynamics of isolated thiophene molecules on Cu(111) by combining helium spin-echo (HeSE) spectroscopy with density functional theory calculations. We show that the thiophene/Cu(111) system displays a rich array of aperiodic dynamical phenomena that include jump diffusion between adjacent atop sites over a 59-62 meV barrier and activated rotation around a sulfur-copper anchor, two processes that have been observed previously for related systems. In addition, we present experimental evidence for a new, weakly activated process, the flapping of the molecular ring. Repulsive inter-adsorbate interactions and an exceptionally high friction coefficient of 5 ± 2 ps(-1) are also observed. These experiments demonstrate the versatility of the HeSE technique, and the quantitative information extracted in a detailed analysis provides an ideal benchmark for state-of-the-art theoretical techniques including nonlocal adsorbate-substrate interactions.

MR CAT scan: a modular approach for hybrid imaging.

PubMed

Hillenbrand, C; Hahn, D; Haase, A; Jakob, P M

2000-07-01

In this study, a modular concept for NMR hybrid imaging is presented. This concept essentially integrates different imaging modules in a sequential fashion and is therefore called CAT (combined acquisition technique). CAT is not a single specific measurement sequence, but rather a sequence design concept whereby distinct acquisition techniques with varying imaging parameters are employed in rapid succession in order to cover k-space. The power of the CAT approach is that it provides a high flexibility toward the acquisition optimization with respect to the available imaging time and the desired image quality. Important CAT sequence optimization steps include the appropriate choice of the k-space coverage ratio and the application of mixed bandwidth technology. Details of both the CAT methodology and possible CAT acquisition strategies, such as FLASH/EPI-, RARE/EPI- and FLASH/BURST-CAT are provided. Examples from imaging experiments in phantoms and healthy volunteers including mixed bandwidth acquisitions are provided to demonstrate the feasibility of the proposed CAT concept.

Future trends in commercial and military systems

NASA Astrophysics Data System (ADS)

Bond, F. E.

Commercial and military satellite communication systems are addressed, with a review of current applications and typical communication characteristics of the space and earth segments. Drivers for the development of future commercial systems include: the pervasion of digital techniques and services, growing orbit and frequency congestion, demand for more entertainment, and the large potential market for commercial 'roof-top' service. For military systems, survivability, improved flexibility, and the need for service to small mobile terminals are the principal factors involved. Technical trends include the use of higher frequency bands, multibeam antennas and a significant increase in the application of onboard processing. Military systems will employ a variety of techniques to counter both physical and electronic threats. The use of redundant transmission paths is a particularly effective approach. Successful implementation requires transmission standards to achieve the required interoperability among the pertinent networks. For both the military and commercial sectors, the trend toward larger numbers of terminals and more complex spacecraft is still persisting.

Imaging System Model Crammed Into A 32K Microcomputer

NASA Astrophysics Data System (ADS)

Tyson, Robert K.

1986-12-01

An imaging system model, based upon linear systems theory, has been developed for a microcomputer with less than 32K of free random access memory (RAM). The model includes diffraction effects of the optics, aberrations in the optics, and atmospheric propagation transfer functions. Variables include pupil geometry, magnitude and character of the aberrations, and strength of atmospheric turbulence ("seeing"). Both coherent and incoherent image formation can be evaluated. The techniques employed for crowding the model into a very small computer will be discussed in detail. Simplifying assumptions for the diffraction and aberration phenomena will be shown along with practical considerations in modeling the optical system. Particular emphasis is placed on avoiding inaccuracies in modeling the pupil and the associated optical transfer function knowing limits on spatial frequency content and resolution. Memory and runtime constraints are analyzed stressing the efficient use of assembly language Fourier transform routines, disk input/output, and graphic displays. The compromises between computer time, limited RAM, and scientific accuracy will be given with techniques for balancing these parameters for individual needs.

The analytical representation of viscoelastic material properties using optimization techniques

NASA Technical Reports Server (NTRS)

Hill, S. A.

1993-01-01

This report presents a technique to model viscoelastic material properties with a function of the form of the Prony series. Generally, the method employed to determine the function constants requires assuming values for the exponential constants of the function and then resolving the remaining constants through linear least-squares techniques. The technique presented here allows all the constants to be analytically determined through optimization techniques. This technique is employed in a computer program named PRONY and makes use of commercially available optimization tool developed by VMA Engineering, Inc. The PRONY program was utilized to compare the technique against previously determined models for solid rocket motor TP-H1148 propellant and V747-75 Viton fluoroelastomer. In both cases, the optimization technique generated functions that modeled the test data with at least an order of magnitude better correlation. This technique has demonstrated the capability to use small or large data sets and to use data sets that have uniformly or nonuniformly spaced data pairs. The reduction of experimental data to accurate mathematical models is a vital part of most scientific and engineering research. This technique of regression through optimization can be applied to other mathematical models that are difficult to fit to experimental data through traditional regression techniques.

Effects of remediation train sequence on decontamination of heavy metal-contaminated soil containing mercury.

PubMed

Hseu, Zeng-Yei; Huang, Yu-Tuan; Hsi, Hsing-Cheng

2014-09-01

When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (> 50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550 degrees C with a heating rate of 5 degrees C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550 degrees C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg. Implications: A remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants.

Built to last? The sustainability of health system improvements, interventions and change strategies: a study protocol for a systematic review.

PubMed

Braithwaite, Jeffrey; Testa, Luke; Lamprell, Gina; Herkes, Jessica; Ludlow, Kristiana; McPherson, Elise; Campbell, Margie; Holt, Joanna

2017-11-12

The sustainability of healthcare interventions and change programmes is of increasing importance to researchers and healthcare stakeholders interested in creating sustainable health systems to cope with mounting stressors. The aim of this protocol is to extend earlier work and describe a systematic review to identify, synthesise and draw meaning from studies published within the last 5 years that measure the sustainability of interventions, improvement efforts and change strategies in the health system. The protocol outlines a method by which to execute a rigorous systematic review. The design includes applying primary and secondary data collection techniques, consisting of a comprehensive database search complemented by contact with experts, and searching secondary databases and reference lists, using snowballing techniques. The review and analysis process will occur via an abstract review followed by a full-text screening process. The inclusion criteria include English-language, peer-reviewed, primary, empirical research articles published after 2011 in scholarly journals, for which the full text is available. No restrictions on location will be applied. The review that results from this protocol will synthesise and compare characteristics of the included studies. Ultimately, it is intended that this will help make it easier to identify and design sustainable interventions, improvement efforts and change strategies. As no primary data were collected, ethical approval was not required. Results will be disseminated in conference presentations, peer-reviewed publications and among policymaker bodies interested in creating sustainable health systems. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Quantum simulation of an ultrathin body field-effect transistor with channel imperfections

NASA Astrophysics Data System (ADS)

Vyurkov, V.; Semenikhin, I.; Filippov, S.; Orlikovsky, A.

2012-04-01

An efficient program for the all-quantum simulation of nanometer field-effect transistors is elaborated. The model is based on the Landauer-Buttiker approach. Our calculation of transmission coefficients employs a transfer-matrix technique involving the arbitrary precision (multiprecision) arithmetic to cope with evanescent modes. Modified in such way, the transfer-matrix technique turns out to be much faster in practical simulations than that of scattering-matrix. Results of the simulation demonstrate the impact of realistic channel imperfections (random charged centers and wall roughness) on transistor characteristics. The Landauer-Buttiker approach is developed to incorporate calculation of the noise at an arbitrary temperature. We also validate the ballistic Landauer-Buttiker approach for the usual situation when heavily doped contacts are indispensably included into the simulation region.

PVT Degradation Studies: Acoustic Diagnostics

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

Dib, Gerges; Tucker, Brian J.; Kouzes, Richard T.

Under certain environmental conditions, polyvinyl toluene (PVT) plastic scintillator has been observed to undergo internal fogging. This document reports on a study of acoustic techniques to determine whether they can provide a diagnostic for the fogging of PVT. Different ultrasound techniques were employed for detecting the level of internal fogging in PVT, including wave velocity measurements, attenuation, nonlinear acoustics, and acoustic microscopy. The results indicate that there are linear relations between the wave velocity and wave attenuation with the level of internal fogging. The effects of fogging on ultrasound wave attenuation is further verified by acoustic microscopy imaging, where regionsmore » with fog in the specimen demonstration higher levels of attenuation compared to clear regions. Results from the nonlinear ultrasound measurements were inconclusive due to high sensitivities to transducer coupling and fixture variabilities.« less

Robotic inspection of fiber reinforced composites using phased array UT

NASA Astrophysics Data System (ADS)

Stetson, Jeffrey T.; De Odorico, Walter

2014-02-01

Ultrasound is the current NDE method of choice to inspect large fiber reinforced airframe structures. Over the last 15 years Cartesian based scanning machines using conventional ultrasound techniques have been employed by all airframe OEMs and their top tier suppliers to perform these inspections. Technical advances in both computing power and commercially available, multi-axis robots now facilitate a new generation of scanning machines. These machines use multiple end effector tools taking full advantage of phased array ultrasound technologies yielding substantial improvements in inspection quality and productivity. This paper outlines the general architecture for these new robotic scanning systems as well as details the variety of ultrasonic techniques available for use with them including advances such as wide area phased array scanning and sound field adaptation for non-flat, non-parallel surfaces.

Soft computing methods for geoidal height transformation

NASA Astrophysics Data System (ADS)

Akyilmaz, O.; Özlüdemir, M. T.; Ayan, T.; Çelik, R. N.

2009-07-01

Soft computing techniques, such as fuzzy logic and artificial neural network (ANN) approaches, have enabled researchers to create precise models for use in many scientific and engineering applications. Applications that can be employed in geodetic studies include the estimation of earth rotation parameters and the determination of mean sea level changes. Another important field of geodesy in which these computing techniques can be applied is geoidal height transformation. We report here our use of a conventional polynomial model, the Adaptive Network-based Fuzzy (or in some publications, Adaptive Neuro-Fuzzy) Inference System (ANFIS), an ANN and a modified ANN approach to approximate geoid heights. These approximation models have been tested on a number of test points. The results obtained through the transformation processes from ellipsoidal heights into local levelling heights have also been compared.

Establishment and rapid detection of a heterozygous missense mutation in the CACNA1F gene by ARMS technique with double-base mismatched primers.

PubMed

Yang, W C; Zhu, L; Zhou, B X; Tania, S; Zhou, Q; Khan, M A; Fu, X L; Cheng, J L; Lv, H B; Fu, J J

2015-09-25

Retinitis pigmentosa (RP) is a retinal degenerative disorder that often causes complete blindness. Mutations of more than 50 genes have been identified as associated with RP, including the CACNA1F gene. In a recent study, by employing next-generation sequencing, we identified a novel mutation in the CACNA1F gene. In this study, we used the amplification refractory mutation system (ARMS) and identified a single nucleotide change c.1555C>T in exon 13 of the CACNA1F gene, leading to the substitution of arginine by tryptophan (p.R519W) in a Chinese individual affected by RP. This study actually confirms this novel mutation, and establishes the ARMS technique for the detection of mutations in RP.

Pressure- and Temperature-Sensitive Paint at 0.3-m Transonic Cryogenic Tunnel

NASA Technical Reports Server (NTRS)

Watkins, A. Neal; Leighty, Bradley D.; Lipford, William E.; Goodman, Kyle Z.

2015-01-01

Recently both Pressure- and Temperature-Sensitive Paint experiments were conducted at cryogenic conditions in the 0.3-m Transonic Cryogenic Tunnel at NASA Langley Research Center. This represented a re-introduction of the techniques to the facility after more than a decade, and provided a means to upgrade the measurements using newer technology as well as demonstrate that the techniques were still viable in the facility. Temperature-Sensitive Paint was employed on a laminar airfoil for transition detection and Pressure-Sensitive Paint was employed on a supercritical airfoil. This report will detail the techniques and their unique challenges that need to be overcome in cryogenic environments. In addition, several optimization strategies will also be discussed.

Real-time optical signal processors employing optical feedback: amplitude and phase control.

PubMed

Gallagher, N C

1976-04-01

The development of real-time coherent optical signal processors has increased the appeal of optical computing techniques in signal processing applications. A major limitation of these real-time systems is the. fact that the optical processing material is generally of a phase-only type. The result is that the spatial filters synthesized with these systems must be either phase-only filters or amplitude-only filters. The main concern of this paper is the application of optical feedback techniques to obtain simultaneous and independent amplitude and phase control of the light passing through the system. It is shown that optical feedback techniques may be employed with phase-only spatial filters to obtain this amplitude and phase control. The feedback system with phase-only filters is compared with other feedback systems that employ combinations of phase-only and amplitude-only filters; it is found that the phase-only system is substantially more flexible than the other two systems investigated.

Building Jobs, Rebuilding Lives: Placing Ex-Offenders with Employers in the Residential and Light Commercial Construction Industry.

ERIC Educational Resources Information Center

Home Builders Inst., Washington, DC.

This guide presents a focused, structured method of facilitating ex-offender employment. Section 1 takes classic marketing techniques and adapts them to the needs of the particular situation, placing ex-offenders in meaningful employment. The set of specific requirements for creating a workable marketing plan is condensed to six basic steps that…

Heavy metals in atmospheric surrogate dry deposition

PubMed

Morselli; Cecchini; Grandi; Iannuccilli; Barilli; Olivieri

1999-02-01

This paper describes a methodological approach for the assessment of the amount of surrogate dry deposition of several toxic heavy metals (Cd, Cr, Cu, Ni, Pb, V, Zn) associated with atmospheric particulate matter at ground level. The objectives of the study were twofold: i) the evaluation of several techniques for the digestion of dry deposition samples for trace metal analysis; ii) the comparison of the results from two samplers with different collecting surfaces. A dry solid surface sampler (DRY sampler, Andersen--USA) and a water layer surface sampler (DAS sampler--MTX Italy) were employed. The samples were collected over a one-year period in an urban site of Bologna (northern Italy). A description is given of the complete procedure, from sampling to data elaboration, including sample storage, digestion and analytical methods. According to the results obtained with three different digestion techniques (Teflon bomb, microwave digester and Teflon flask with vapour cooling system), the highest recovery rate was achieved by the Teflon bomb procedure employing an NBS 1648 Standard Reference Material; 90-95% of the elements considered were recovered by dissolution in a pressurized Teflon bomb with an HNO3-HF mixture. Given these results, the technique was adopted for dry deposition sample digestion. On the basis of the amount of heavy metals measured as monthly deposition fluxes (microg/m2), the collecting efficiency of the DAS sampler for a number of elements was found to be as much as two to three times greater than that of the DRY sampler.

Fully Integrated Microfluidic Device for Direct Sample-to-Answer Genetic Analysis

NASA Astrophysics Data System (ADS)

Liu, Robin H.; Grodzinski, Piotr

Integration of microfluidics technology with DNA microarrays enables building complete sample-to-answer systems that are useful in many applications such as clinic diagnostics. In this chapter, a fully integrated microfluidic device [1] that consists of microfluidic mixers, valves, pumps, channels, chambers, heaters, and a DNA microarray sensor to perform DNA analysis of complex biological sample solutions is present. This device can perform on-chip sample preparation (including magnetic bead-based cell capture, cell preconcentration and purification, and cell lysis) of complex biological sample solutions (such as whole blood), polymerase chain reaction, DNA hybridization, and electrochemical detection. A few novel microfluidic techniques were developed and employed. A micromix-ing technique based on a cavitation microstreaming principle was implemented to enhance target cell capture from whole blood samples using immunomagnetic beads. This technique was also employed to accelerate DNA hybridization reaction. Thermally actuated paraffin-based microvalves were developed to regulate flows. Electrochemical pumps and thermopneumatic pumps were integrated on the chip to provide pumping of liquid solutions. The device is completely self-contained: no external pressure sources, fluid storage, mechanical pumps, or valves are necessary for fluid manipulation, thus eliminating possible sample contamination and simplifying device operation. Pathogenic bacteria detection from ~mL whole blood samples and single-nucleotide polymorphism analysis directly from diluted blood were demonstrated. The device provides a cost-effective solution to direct sample-to-answer genetic analysis, and thus has a potential impact in the fields of point-of-care genetic analysis, environmental testing, and biological warfare agent detection.

Combinative Particle Size Reduction Technologies for the Production of Drug Nanocrystals

PubMed Central

Salazar, Jaime; Müller, Rainer H.; Möschwitzer, Jan P.

2014-01-01

Nanosizing is a suitable method to enhance the dissolution rate and therefore the bioavailability of poorly soluble drugs. The success of the particle size reduction processes depends on critical factors such as the employed technology, equipment, and drug physicochemical properties. High pressure homogenization and wet bead milling are standard comminution techniques that have been already employed to successfully formulate poorly soluble drugs and bring them to market. However, these techniques have limitations in their particle size reduction performance, such as long production times and the necessity of employing a micronized drug as the starting material. This review article discusses the development of combinative methods, such as the NANOEDGE, H 96, H 69, H 42, and CT technologies. These processes were developed to improve the particle size reduction effectiveness of the standard techniques. These novel technologies can combine bottom-up and/or top-down techniques in a two-step process. The combinative processes lead in general to improved particle size reduction effectiveness. Faster production of drug nanocrystals and smaller final mean particle sizes are among the main advantages. The combinative particle size reduction technologies are very useful formulation tools, and they will continue acquiring importance for the production of drug nanocrystals. PMID:26556191

Multigrid Strategies for Viscous Flow Solvers on Anisotropic Unstructured Meshes

NASA Technical Reports Server (NTRS)

Movriplis, Dimitri J.

1998-01-01

Unstructured multigrid techniques for relieving the stiffness associated with high-Reynolds number viscous flow simulations on extremely stretched grids are investigated. One approach consists of employing a semi-coarsening or directional-coarsening technique, based on the directions of strong coupling within the mesh, in order to construct more optimal coarse grid levels. An alternate approach is developed which employs directional implicit smoothing with regular fully coarsened multigrid levels. The directional implicit smoothing is obtained by constructing implicit lines in the unstructured mesh based on the directions of strong coupling. Both approaches yield large increases in convergence rates over the traditional explicit full-coarsening multigrid algorithm. However, maximum benefits are achieved by combining the two approaches in a coupled manner into a single algorithm. An order of magnitude increase in convergence rate over the traditional explicit full-coarsening algorithm is demonstrated, and convergence rates for high-Reynolds number viscous flows which are independent of the grid aspect ratio are obtained. Further acceleration is provided by incorporating low-Mach-number preconditioning techniques, and a Newton-GMRES strategy which employs the multigrid scheme as a preconditioner. The compounding effects of these various techniques on speed of convergence is documented through several example test cases.

Neural net diagnostics for VLSI test

NASA Technical Reports Server (NTRS)

Lin, T.; Tseng, H.; Wu, A.; Dogan, N.; Meador, J.

1990-01-01

This paper discusses the application of neural network pattern analysis algorithms to the IC fault diagnosis problem. A fault diagnostic is a decision rule combining what is known about an ideal circuit test response with information about how it is distorted by fabrication variations and measurement noise. The rule is used to detect fault existence in fabricated circuits using real test equipment. Traditional statistical techniques may be used to achieve this goal, but they can employ unrealistic a priori assumptions about measurement data. Our approach to this problem employs an adaptive pattern analysis technique based on feedforward neural networks. During training, a feedforward network automatically captures unknown sample distributions. This is important because distributions arising from the nonlinear effects of process variation can be more complex than is typically assumed. A feedforward network is also able to extract measurement features which contribute significantly to making a correct decision. Traditional feature extraction techniques employ matrix manipulations which can be particularly costly for large measurement vectors. In this paper we discuss a software system which we are developing that uses this approach. We also provide a simple example illustrating the use of the technique for fault detection in an operational amplifier.

Using Medical-Device Wearable to Improve Hemodialysis Patient’s Live and Access the Holistic Health

NASA Astrophysics Data System (ADS)

Chen, W. L.; Wu, C.-C.; Kan, C. D.

2017-06-01

The increasing incidence of end-stage renal disease (ESRD) is the major burden to health budgets and a threat to public health worldwide. For many years, Taiwan has been ranked the first in the world for the number of hemodialysis patients. For solving the above-mentioned circumstance, we demonstrate the project, here, which goal is to construct the holistic health for hemodialysis patient. The project is to design a wearable medicine-device which can simultaneously measure and monitor the vital sign, including heart rate (HR), pulse oximetry (SPO2), continuous non-invasive blood pressure (c-NIBP), and total body water (TBW), of hemodialysis patient. By aid of the device we design, hemodialysis patients will get better health care than before. This device comprises three techniques. The first is named “Using phonoangiography technique to early detect the dysfunction of arteriovenous access by arteriovenous access (AVA) stenosis detector”. The stenosis detector based on autoregressive model was employed to simultaneously estimate the status of AVA life cycle and to tract changes in frequency spectra. It helps hemodialysis patients to early detect the dysfunction of AVA and alarms them to make a return visit. The second technique is named “Physiological detecting device for wearable medical device and encoding algorithm development”. The feature of the second technique is to optimize the prognosis by analyzing physiological signals, including water content index, pulse oximetry, and blood pressure in the meanwhile. The third technique is named “Intelligent and smart tourniquet”. This technique aims to preclude AVA dysfunction caused by inappropriate hemostasis.

Injection drug users trained by overdose prevention programs: Responses to witnessed overdoses

PubMed Central

Lankenau, Stephen E.; Wagner, Karla D.; Silva, Karol; Kecojevic, Aleksander; Iverson, Ellen; McNeely, Miles; Kral, Alex H.

2012-01-01

In response to the growing public health problem of drug overdose, community-based organizations have initiated overdose prevention programs (OPP), which distribute naloxone, an opioid antagonist, and teach overdose response techniques. Injection drug users (IDUs) have been targeted for this intervention due to their high risk for drug overdose. Limited research attention has focused on factors that may inhibit or prevent IDUs who have been trained by OPPs to undertake recommended response techniques when responding to a drug overdose. IDUs (n=30) trained by two OPPs in Los Angeles were interviewed in 2010–11 about responses to their most recently witnessed drug overdose using an instrument containing both open and closed-ended questions. Among the 30 witnessed overdose events, the victim recovered in 29 cases while the outcome was unknown in one case. Participants responded to overdoses using a variety of techniques taught by OPP. Injecting the victim with naloxone was the most common recommended response while other recommended responses included stimulating the victim with knuckles, calling 911, and giving rescue breathing. Barriers preventing participants from employing recommended response techniques in certain circumstances included prior successes using folk remedies to revive a victim, concerns over attracting police to the scene, and issues surrounding access to or use of naloxone. Practical solutions, such as developing booster sessions to augment OPP, are encouraged to increase the likelihood that trained participants respond to a drug overdose with the full range of recommended techniques. PMID:22847602

Nanoassembly of nanostructures by cutting, bending and soldering of carbon nanotubes with electron beam.

PubMed

Liu, Pou; Kantola, Kalle; Fukuda, Toshio; Arai, Fumihito

2009-05-01

We report that a series of in situ nanofabrication techniques of nanostructures, including cutting, bending and soldering of carbon nanotubes (CNTs), inside a field emission scanning electron microscope (FE-SEM) used for nanoassembly of nanostructures. The CNTs can be cut with electron beam assisted with oxygen gas. The cutting was developed for the bending of CNT, if some conditions of the cutting technique are changed. These include the increase of the acceleration voltage and/or setting the oxygen gas nozzle farther from the sample, and/or reducing the irradiation time. Using the proposed bending method angles larger than 90 degrees can be formed and the location of the kink can be set accurately. It is also shown that tungsten can be deposited on a substrate by the electron-beam-induced deposition, if the oxygen of the proposed cutting technique is replaced by W(CO)6. In this paper, these three nanofabrication methods were employed in the creation of a two dimensional (2D) nanostructure, the letters N and U, and a three dimensional (3D) nanostructure, the letter N. The 2D letters were constructed from 6 CNTs assembled on a substrate while the 3D letter N was bended from a single CNT and fixed to stand on a substrate. Based on the high performance of the proposed techniques, it is suggested that the cutting, bending, and soldering techniques inside SEM will become widely utilized in the fabrication and assembly of nanodevices and in the characterization of nanomaterials.

An information theoretic approach to use high-fidelity codes to calibrate low-fidelity codes

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

Lewis, Allison, E-mail: lewis.allison10@gmail.com; Smith, Ralph; Williams, Brian

For many simulation models, it can be prohibitively expensive or physically infeasible to obtain a complete set of experimental data to calibrate model parameters. In such cases, one can alternatively employ validated higher-fidelity codes to generate simulated data, which can be used to calibrate the lower-fidelity code. In this paper, we employ an information-theoretic framework to determine the reduction in parameter uncertainty that is obtained by evaluating the high-fidelity code at a specific set of design conditions. These conditions are chosen sequentially, based on the amount of information that they contribute to the low-fidelity model parameters. The goal is tomore » employ Bayesian experimental design techniques to minimize the number of high-fidelity code evaluations required to accurately calibrate the low-fidelity model. We illustrate the performance of this framework using heat and diffusion examples, a 1-D kinetic neutron diffusion equation, and a particle transport model, and include initial results from the integration of the high-fidelity thermal-hydraulics code Hydra-TH with a low-fidelity exponential model for the friction correlation factor.« less

Analysis of explicit model predictive control for path-following control

PubMed Central

2018-01-01

In this paper, explicit Model Predictive Control(MPC) is employed for automated lane-keeping systems. MPC has been regarded as the key to handle such constrained systems. However, the massive computational complexity of MPC, which employs online optimization, has been a major drawback that limits the range of its target application to relatively small and/or slow problems. Explicit MPC can reduce this computational burden using a multi-parametric quadratic programming technique(mp-QP). The control objective is to derive an optimal front steering wheel angle at each sampling time so that autonomous vehicles travel along desired paths, including straight, circular, and clothoid parts, at high entry speeds. In terms of the design of the proposed controller, a method of choosing weighting matrices in an optimization problem and the range of horizons for path-following control are described through simulations. For the verification of the proposed controller, simulation results obtained using other control methods such as MPC, Linear-Quadratic Regulator(LQR), and driver model are employed, and CarSim, which reflects the features of a vehicle more realistically than MATLAB/Simulink, is used for reliable demonstration. PMID:29534080

Analysis of explicit model predictive control for path-following control.

PubMed

Lee, Junho; Chang, Hyuk-Jun

2018-01-01

In this paper, explicit Model Predictive Control(MPC) is employed for automated lane-keeping systems. MPC has been regarded as the key to handle such constrained systems. However, the massive computational complexity of MPC, which employs online optimization, has been a major drawback that limits the range of its target application to relatively small and/or slow problems. Explicit MPC can reduce this computational burden using a multi-parametric quadratic programming technique(mp-QP). The control objective is to derive an optimal front steering wheel angle at each sampling time so that autonomous vehicles travel along desired paths, including straight, circular, and clothoid parts, at high entry speeds. In terms of the design of the proposed controller, a method of choosing weighting matrices in an optimization problem and the range of horizons for path-following control are described through simulations. For the verification of the proposed controller, simulation results obtained using other control methods such as MPC, Linear-Quadratic Regulator(LQR), and driver model are employed, and CarSim, which reflects the features of a vehicle more realistically than MATLAB/Simulink, is used for reliable demonstration.

Supercritical fluid chromatography for lipid analysis in foodstuffs.

PubMed

Donato, Paola; Inferrera, Veronica; Sciarrone, Danilo; Mondello, Luigi

2017-01-01

The task of lipid analysis has always challenged separation scientists, and new techniques in chromatography were often developed for the separation of lipids; however, no single technique or methodology is yet capable of affording a comprehensive screening of all lipid species and classes. This review acquaints the role of supercritical fluid chromatography within the field of lipid analysis, from the early developed capillary separations based on pure CO 2 , to the most recent techniques employing packed columns under subcritical conditions, including the niche multidimensional techniques using supercritical fluids in at least one of the separation dimensions. A short history of supercritical fluid chromatography will be introduced first, from its early popularity in the late 1980s, to the sudden fall and oblivion until the last decade, experiencing a regain of interest within the chromatographic community. Afterwards, the subject of lipid nomenclature and classification will be briefly dealt with, before discussing the main applications of supercritical fluid chromatography for food analysis, according to the specific class of lipids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Air flow measurement techniques applied to noise reduction of a centrifugal blower

NASA Astrophysics Data System (ADS)

Laage, John W.; Armstrong, Ashli J.; Eilers, Daniel J.; Olsen, Michael G.; Mann, J. Adin

2005-09-01

The air flow in a centrifugal blower was studied using a variety of flow and sound measurement techniques. The flow measurement techniques employed included Particle Image Velocimetry (PIV), pitot tubes, and a five hole spherical probe. PIV was used to measure instantaneous and ensemble-averaged velocity fields over large area of the outlet duct as a function of fan position, allowing for the visualization of the flow as it leave the fan blades and progressed downstream. The results from the flow measurements were reviewed along side the results of the sound measurements with the goal of identifying sources of noise and inefficiencies in flow performance. The radiated sound power was divided into broadband and tone noise and measures of the flow. The changes in the tone and broadband sound were compared to changes in flow quantities such as the turbulent kinetic energy and Reynolds stress. Results for each method will be presented to demonstrate the strengths of each flow measurement technique as well as their limitations. Finally, the role that each played in identifying noise sources is described.

[Gastric band erosion: Alternative management].

PubMed

Echaverry-Navarrete, Denis José; Maldonado-Vázquez, Angélica; Cortes-Romano, Pablo; Cabrera-Jardines, Ricardo; Mondragón-Pinzón, Erwin Eduardo; Castillo-González, Federico Armando

2015-01-01

Obesity is a public health problem, for which the prevalence has increased worldwide at an alarming rate, affecting 1.7 billion people in the world. To describe the technique employed in incomplete penetration of gastric band where endoscopic management and/or primary closure is not feasible. Laparoscopic removal of gastric band was performed in five patients with incomplete penetrance using Foley catheterization in the perforation site that could lead to the development of a gastro-cutaneous fistula. The cases presented include a leak that required surgical lavage with satisfactory outcome, and one patient developed stenosis 3 years after surgical management, which was resolved endoscopically. In all cases, the penetration site closed spontaneously. Gastric band erosion has been reported in 3.4% of cases. The reason for inserting a catheter is to create a controlled gastro-cutaneous fistula, allowing spontaneous closure. Various techniques have been described: the totally endoscopic, hybrid techniques (endoscopic/laparoscopic) and completely laparoscopic. A technique is described here that is useful and successful in cases where the above-described treatments are not viable. Copyright © 2015. Published by Masson Doyma México S.A.

Creative user-centered visualization design for energy analysts and modelers.

PubMed

Goodwin, Sarah; Dykes, Jason; Jones, Sara; Dillingham, Iain; Dove, Graham; Duffy, Alison; Kachkaev, Alexander; Slingsby, Aidan; Wood, Jo

2013-12-01

We enhance a user-centered design process with techniques that deliberately promote creativity to identify opportunities for the visualization of data generated by a major energy supplier. Visualization prototypes developed in this way prove effective in a situation whereby data sets are largely unknown and requirements open - enabling successful exploration of possibilities for visualization in Smart Home data analysis. The process gives rise to novel designs and design metaphors including data sculpting. It suggests: that the deliberate use of creativity techniques with data stakeholders is likely to contribute to successful, novel and effective solutions; that being explicit about creativity may contribute to designers developing creative solutions; that using creativity techniques early in the design process may result in a creative approach persisting throughout the process. The work constitutes the first systematic visualization design for a data rich source that will be increasingly important to energy suppliers and consumers as Smart Meter technology is widely deployed. It is novel in explicitly employing creativity techniques at the requirements stage of visualization design and development, paving the way for further use and study of creativity methods in visualization design.

Convection in containerless processing.

PubMed

Hyers, Robert W; Matson, Douglas M; Kelton, Kenneth F; Rogers, Jan R

2004-11-01

Different containerless processing techniques have different strengths and weaknesses. Applying more than one technique allows various parts of a problem to be solved separately. For two research projects, one on phase selection in steels and the other on nucleation and growth of quasicrystals, a combination of experiments using electrostatic levitation (ESL) and electromagnetic levitation (EML) is appropriate. In both experiments, convection is an important variable. The convective conditions achievable with each method are compared for two very different materials: a low-viscosity, high-temperature stainless steel, and a high-viscosity, low-temperature quasicrystal-forming alloy. It is clear that the techniques are complementary when convection is a parameter to be explored in the experiments. For a number of reasons, including the sample size, temperature, and reactivity, direct measurement of the convective velocity is not feasible. Therefore, we must rely on computation techniques to estimate convection in these experiments. These models are an essential part of almost any microgravity investigation. The methods employed and results obtained for the projects levitation observation of dendrite evolution in steel ternary alloy rapid solidification (LODESTARS) and quasicrystalline undercooled alloys for space investigation (QUASI) are explained.

Efficient sweep buffering in swept source optical coherence tomography using a fast optical switch

PubMed Central

Dhalla, Al-Hafeez; Shia, Kevin; Izatt, Joseph A.

2012-01-01

We describe a novel buffering technique for increasing the A-scan rate of swept source optical coherence tomography (SSOCT) systems employing low duty cycle swept source lasers. This technique differs from previously reported buffering techniques in that it employs a fast optical switch, capable of switching in 60 ns, instead of a fused fiber coupler at the end of the buffering stage, and is therefore appreciably more power efficient. The use of the switch also eliminates patient exposure to light that is not used for imaging that occurs at the end of the laser sweep, thereby increasing the system sensitivity. We also describe how careful management of polarization can remove undesirable artifacts due to polarization mode dispersion. In addition, we demonstrate how numerical compensation techniques can be used to modify the signal from a Mach-Zehnder interferometer (MZI) clock obtained from the original sweep to recalibrate the buffered sweep, thereby reducing the complexity of systems employing lasers with integrated MZI clocks. Combining these methods, we constructed an SSOCT system employing an Axsun technologies laser with a sweep rate of 100kHz and 6dB imaging range of 5.5mm. The sweep rate was doubled with sweep buffering to 200 kHz, and the imaging depth was extended to 9 mm using coherence revival. We demonstrated the feasibility of this system by acquiring images of the anterior segments and retinas of healthy human volunteers. PMID:23243559

Efficient sweep buffering in swept source optical coherence tomography using a fast optical switch.

PubMed

Dhalla, Al-Hafeez; Shia, Kevin; Izatt, Joseph A

2012-12-01

We describe a novel buffering technique for increasing the A-scan rate of swept source optical coherence tomography (SSOCT) systems employing low duty cycle swept source lasers. This technique differs from previously reported buffering techniques in that it employs a fast optical switch, capable of switching in 60 ns, instead of a fused fiber coupler at the end of the buffering stage, and is therefore appreciably more power efficient. The use of the switch also eliminates patient exposure to light that is not used for imaging that occurs at the end of the laser sweep, thereby increasing the system sensitivity. We also describe how careful management of polarization can remove undesirable artifacts due to polarization mode dispersion. In addition, we demonstrate how numerical compensation techniques can be used to modify the signal from a Mach-Zehnder interferometer (MZI) clock obtained from the original sweep to recalibrate the buffered sweep, thereby reducing the complexity of systems employing lasers with integrated MZI clocks. Combining these methods, we constructed an SSOCT system employing an Axsun technologies laser with a sweep rate of 100kHz and 6dB imaging range of 5.5mm. The sweep rate was doubled with sweep buffering to 200 kHz, and the imaging depth was extended to 9 mm using coherence revival. We demonstrated the feasibility of this system by acquiring images of the anterior segments and retinas of healthy human volunteers.

Boosting production yield of biomedical peptides

NASA Technical Reports Server (NTRS)

Manatt, S. L.

1978-01-01

Nuclear magnetic resonance (NMR) technique is employed to monitor synthesis of biomedical peptides. Application of NMR technique may improve production yields of insulin, ACTH, and growth hormones, as well as other synthesized biomedical peptides.

Microscale Titration in Schools Titration Competition.

ERIC Educational Resources Information Center

Clark, Michael J.

1998-01-01

Reviews the requirements of the National Titration Competition and describes how a team in a local competition used the technique. Compares microscale titration to conventional titration. Outlines the benefits of employing microscale techniques. (DDR)

Improved Tandem Measurement Techniques for Aerosol Particle Analysis

NASA Astrophysics Data System (ADS)

Rawat, Vivek Kumar

Non-spherical, chemically inhomogeneous (complex) nanoparticles are encountered in a number of natural and engineered environments, including combustion systems (which produces highly non-spherical aggregates), reactors used in gas-phase materials synthesis of doped or multicomponent materials, and in ambient air. These nanoparticles are often highly diverse in size, composition and shape, and hence require determination of property distribution functions for accurate characterization. This thesis focuses on development of tandem mobility-mass measurement techniques coupled with appropriate data inversion routines to facilitate measurement of two dimensional size-mass distribution functions while correcting for the non-idealities of the instruments. Chapter 1 provides the detailed background and motivation for the studies performed in this thesis. In chapter 2, the development of an inversion routine is described which is employed to determine two dimensional size-mass distribution functions from Differential Mobility Analyzer-Aerosol Particle Mass analyzer tandem measurements. Chapter 3 demonstrates the application of the two dimensional distribution function to compute cumulative mass distribution function and also evaluates the validity of this technique by comparing the calculated total mass concentrations to measured values for a variety of aerosols. In Chapter 4, this tandem measurement technique with the inversion routine is employed to analyze colloidal suspensions. Chapter 5 focuses on application of a transverse modulation ion mobility spectrometer coupled with a mass spectrometer to study the effect of vapor dopants on the mobility shifts of sub 2 nm peptide ion clusters. These mobility shifts are then compared to models based on vapor uptake theories. Finally, in Chapter 6, a conclusion of all the studies performed in this thesis is provided and future avenues of research are discussed.

Thermal and Chemical Characterization of Non-Metallic Materials Using Coupled Thermogravimetric Analysis and Infrared Spectroscopy

NASA Technical Reports Server (NTRS)

Huff, Timothy L.

2002-01-01

Thermogravimetric analysis (TGA) is widely employed in the thermal characterization of non-metallic materials, yielding valuable information on decomposition characteristics of a sample over a wide temperature range. However, a potential wealth of chemical information is lost during the process, with the evolving gases generated during thermal decomposition escaping through the exhaust line. Fourier Transform-Infrared spectroscopy (FT-IR) is a powerful analytical technique for determining many chemical constituents while in any material state, in this application, the gas phase. By linking these two techniques, evolving gases generated during the TGA process are directed into an appropriately equipped infrared spectrometer for chemical speciation. Consequently, both thermal decomposition and chemical characterization of a material may be obtained in a single sample run. In practice, a heated transfer line is employed to connect the two instruments while a purge gas stream directs the evolving gases into the FT-IR. The purge gas can be either high purity air or an inert gas such as nitrogen to allow oxidative and pyrolytic processes to be examined, respectively. The FT-IR data is collected realtime, allowing continuous monitoring of chemical compositional changes over the course of thermal decomposition. Using this coupled technique, an array of diverse materials has been examined, including composites, plastics, rubber, fiberglass epoxy resins, polycarbonates, silicones, lubricants and fluorocarbon materials. The benefit of combining these two methodologies is of particular importance in the aerospace community, where newly developing materials have little available data with which to refer. By providing both thermal and chemical data simultaneously, a more definitive and comprehensive characterization of the material is possible. Additionally, this procedure has been found to be a viable screening technique for certain materials, with the generated data useful in the selection of other appropriate analytical procedures for further material characterization.

Global Design Optimization for Aerodynamics and Rocket Propulsion Components

NASA Technical Reports Server (NTRS)

Shyy, Wei; Papila, Nilay; Vaidyanathan, Rajkumar; Tucker, Kevin; Turner, James E. (Technical Monitor)

2000-01-01

Modern computational and experimental tools for aerodynamics and propulsion applications have matured to a stage where they can provide substantial insight into engineering processes involving fluid flows, and can be fruitfully utilized to help improve the design of practical devices. In particular, rapid and continuous development in aerospace engineering demands that new design concepts be regularly proposed to meet goals for increased performance, robustness and safety while concurrently decreasing cost. To date, the majority of the effort in design optimization of fluid dynamics has relied on gradient-based search algorithms. Global optimization methods can utilize the information collected from various sources and by different tools. These methods offer multi-criterion optimization, handle the existence of multiple design points and trade-offs via insight into the entire design space, can easily perform tasks in parallel, and are often effective in filtering the noise intrinsic to numerical and experimental data. However, a successful application of the global optimization method needs to address issues related to data requirements with an increase in the number of design variables, and methods for predicting the model performance. In this article, we review recent progress made in establishing suitable global optimization techniques employing neural network and polynomial-based response surface methodologies. Issues addressed include techniques for construction of the response surface, design of experiment techniques for supplying information in an economical manner, optimization procedures and multi-level techniques, and assessment of relative performance between polynomials and neural networks. Examples drawn from wing aerodynamics, turbulent diffuser flows, gas-gas injectors, and supersonic turbines are employed to help demonstrate the issues involved in an engineering design context. Both the usefulness of the existing knowledge to aid current design practices and the need for future research are identified.