The Soft Seal disposable laryngeal mask airway in adults: comparison of two insertion techniques without intra-oral manipulation.

PubMed

Kuvaki, B; Küçükgüçlü, S; Iyilikçi, L; Tuncali, B E; Cinar, O

2008-10-01

We investigated whether insertion of the disposable Soft Seal laryngeal mask airway (SSLM) was successful without intra-oral digital manipulation. One hundred patients undergoing anaesthesia using the SSLM were randomly assigned into two groups. Insertion was performed by either a direct or a rotational technique, both without intra-oral digital manipulation. The primary outcome measure was successful insertion at first attempt. Other outcomes included insertion time, fibreoptic assessment of the airway view and airway morbidity. The first attempt success rate was higher (98%) with the direct technique than with the rotational technique (75%; p = 0.002) but insertion time was faster with the latter method (mean [range] 15 [8-50] s) than with the direct method (20 [8-56] s; p = 0.035). Fibreoptic assessment and airway morbidity were similar in both groups. We conclude that the SSLM can be successfully inserted without intra-oral digital manipulation.

Directional analysis and filtering for dust storm detection in NOAA-AVHRR imagery

NASA Astrophysics Data System (ADS)

Janugani, S.; Jayaram, V.; Cabrera, S. D.; Rosiles, J. G.; Gill, T. E.; Rivera Rivera, N.

2009-05-01

In this paper, we propose spatio-spectral processing techniques for the detection of dust storms and automatically finding its transport direction in 5-band NOAA-AVHRR imagery. Previous methods that use simple band math analysis have produced promising results but have drawbacks in producing consistent results when low signal to noise ratio (SNR) images are used. Moreover, in seeking to automate the dust storm detection, the presence of clouds in the vicinity of the dust storm creates a challenge in being able to distinguish these two types of image texture. This paper not only addresses the detection of the dust storm in the imagery, it also attempts to find the transport direction and the location of the sources of the dust storm. We propose a spatio-spectral processing approach with two components: visualization and automation. Both approaches are based on digital image processing techniques including directional analysis and filtering. The visualization technique is intended to enhance the image in order to locate the dust sources. The automation technique is proposed to detect the transport direction of the dust storm. These techniques can be used in a system to provide timely warnings of dust storms or hazard assessments for transportation, aviation, environmental safety, and public health.

"Soft"or "hard" ionisation? Investigation of metastable gas temperature effect on direct analysis in real-time analysis of Voriconazole.

PubMed

Lapthorn, Cris; Pullen, Frank

2009-01-01

The performance of the direct analysis in real-time (DART) technique was evaluated across a range of metastable gas temperatures for a pharmaceutical compound, Voriconazole, in order to investigate the effect of metastable gas temperature on molecular ion intensity and fragmentation. The DART source has been used to analyse a range of analytes and from a range of matrices including drugs in solid tablet form and preparations, active ingredients in ointment, naturally occurring plant alkaloids, flavours and fragrances, from thin layer chromatography (TLC) plates, melting point tubes and biological matrices including hair, urine and blood. The advantages of this technique include rapid analysis time (as little as 5 s), a reduction in sample preparation requirements, elimination of mobile phase requirement and analysis of samples not typically amenable to atmospheric pressure ionisation (API) techniques. This technology has therefore been proposed as an everyday tool for identification of components in crude organic reaction mixtures.

Digital synchronization and communication techniques

NASA Technical Reports Server (NTRS)

Lindsey, William C.

1992-01-01

Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.

On-Wafer Characterization of Millimeter-Wave Antennas for Wireless Applications

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Lee, Richard Q.

1998-01-01

The paper demonstrates a de-embedding technique and a direct on-substrate measurement technique for fast and inexpensive characterization of miniature antennas for wireless applications at millimeter-wave frequencies. The technique is demonstrated by measurements on a tapered slot antenna (TSA). The measured results at Ka-Band frequencies include input impedance, mutual coupling between two TSAs and absolute gain of TSA.

A "reverse direction" technique of single-port left upper pulmonary resection.

PubMed

Zhang, Min; Sihoe, Alan D L; Du, Ming

2016-08-01

Single-port video-assisted thoracoscopic surgery (VATS) left upper lobectomy is difficult amongst all the lobes. At the beginning of single-port lobectomies, the upper lobes were believed not to be amenable for single-port approach due to the difficult angulation for staplers. Gonzalez reported the first single-port VATS left upper lobectomy in 2011. We report a new technique of single-port VATS left upper lobectomy with the concept of "reverse direction". We divide the apical-anterior arterial trunk with upper vein in the last. The procedure sequence is described as follows: posterior artery, lingular artery, bronchus and finally upper vein & apical-anterior arterial trunk. This method could overcome the angular limitations frequently encountered in single-port VATS procedures; reduce the risk of injuries to pulmonary artery; broaden the indications of single-port the upper lobe of the left lung (LUL) to include hypoplastic lung fissures. Limitations of this new practice include the enlargement or severe calcifications of hilar and bronchial lymph nodes. A "reverse direction" technique of single-port left upper pulmonary resection is feasible and safe.

Techniques for the analysis of data from coded-mask X-ray telescopes

NASA Technical Reports Server (NTRS)

Skinner, G. K.; Ponman, T. J.; Hammersley, A. P.; Eyles, C. J.

1987-01-01

Several techniques useful in the analysis of data from coded-mask telescopes are presented. Methods of handling changes in the instrument pointing direction are reviewed and ways of using FFT techniques to do the deconvolution considered. Emphasis is on techniques for optimally-coded systems, but it is shown that the range of systems included in this class can be extended through the new concept of 'partial cycle averaging'.

A comparison of the techniques of direct pars interarticularis repairs for spondylolysis and low-grade spondylolisthesis: a meta-analysis.

PubMed

Mohammed, Nasser; Patra, Devi Prasad; Narayan, Vinayak; Savardekar, Amey R; Dossani, Rimal Hanif; Bollam, Papireddy; Bir, Shyamal; Nanda, Anil

2018-01-01

OBJECTIVE Spondylosis with or without spondylolisthesis that does not respond to conservative management has an excellent outcome with direct pars interarticularis repair. Direct repair preserves the segmental spinal motion. A number of operative techniques for direct repair are practiced; however, the procedure of choice is not clearly defined. The present study aims to clarify the advantages and disadvantages of the different operative techniques and their outcomes. METHODS A meta-analysis was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The following databases were searched: PubMed, Cochrane Library, Web of Science, and CINAHL ( Cumulative Index to Nursing and Allied Health Literature). Studies of patients with spondylolysis with or without low-grade spondylolisthesis who underwent direct repair were included. The patients were divided into 4 groups based on the operative technique used: the Buck repair group, Scott repair group, Morscher repair group, and pedicle screw-based repair group. The pooled data were analyzed using the DerSimonian and Laird random-effects model. Tests for bias and heterogeneity were performed. The I 2 statistic was calculated, and the results were analyzed. Statistical analysis was performed using StatsDirect version 2. RESULTS Forty-six studies consisting of 900 patients were included in the study. The majority of the patients were in their 2nd decade of life. The Buck group included 19 studies with 305 patients; the Scott group had 8 studies with 162 patients. The Morscher method included 5 studies with 193 patients, and the pedicle group included 14 studies with 240 patients. The overall pooled fusion, complication, and outcome rates were calculated. The pooled rates for fusion for the Buck, Scott, Morscher, and pedicle screw groups were 83.53%, 81.57%, 77.72%, and 90.21%, respectively. The pooled complication rates for the Buck, Scott, Morscher, and pedicle screw groups were 13.41%, 22.35%, 27.42%, and 12.8%, respectively, and the pooled positive outcome rates for the Buck, Scott, Morscher, and pedicle screw groups were 84.33%, 82.49%, 80.30%, and 80.1%, respectively. The pedicle group had the best fusion rate and lowest complication rate. CONCLUSIONS The pedicle screw-based direct pars repair for spondylolysis and low-grade spondylolisthesis is the best choice of procedure, with the highest fusion and lowest complication rates, followed by the Buck repair. The Morscher and Scott repairs were associated with a high rate of complication and lower rates of fusion.

X-Ray Microanalysis and Electron Energy Loss Spectrometry in the Analytical Electron Microscope: Review and Future Directions

NASA Technical Reports Server (NTRS)

Goldstein, J. I.; Williams, D. B.

1992-01-01

This paper reviews and discusses future directions in analytical electron microscopy for microchemical analysis using X-ray and Electron Energy Loss Spectroscopy (EELS). The technique of X-ray microanalysis, using the ratio method and k(sub AB) factors, is outlined. The X-ray absorption correction is the major barrier to the objective of obtaining I% accuracy and precision in analysis. Spatial resolution and Minimum Detectability Limits (MDL) are considered with present limitations of spatial resolution in the 2 to 3 microns range and of MDL in the 0.1 to 0.2 wt. % range when a Field Emission Gun (FEG) system is used. Future directions of X-ray analysis include improvement in X-ray spatial resolution to the I to 2 microns range and MDL as low as 0.01 wt. %. With these improvements the detection of single atoms in the analysis volume will be possible. Other future improvements include the use of clean room techniques for thin specimen preparation, quantification available at the I% accuracy and precision level with light element analysis quantification available at better than the 10% accuracy and precision level, the incorporation of a compact wavelength dispersive spectrometer to improve X-ray spectral resolution, light element analysis and MDL, and instrument improvements including source stability, on-line probe current measurements, stage stability, and computerized stage control. The paper reviews the EELS technique, recognizing that it has been slow to develop and still remains firmly in research laboratories rather than in applications laboratories. Consideration of microanalysis with core-loss edges is given along with a discussion of the limitations such as specimen thickness. Spatial resolution and MDL are considered, recognizing that single atom detection is already possible. Plasmon loss analysis is discussed as well as fine structure analysis. New techniques for energy-loss imaging are also summarized. Future directions in the EELS technique will be the development of new spectrometers and improvements in thin specimen preparation. The microanalysis technique needs to be simplified and software developed so that the EELS technique approaches the relative simplicity of the X-ray technique. Finally, one can expect major improvements in EELS imaging as data storage and processing improvements occur.

EUS-guided gastroenterostomy: a multicenter study comparing the direct and balloon-assisted techniques.

PubMed

Chen, Yen-I; Kunda, Rastislav; Storm, Andrew C; Aridi, Hanaa Dakour; Thompson, Christopher C; Nieto, Jose; James, Theodore; Irani, Shayan; Bukhari, Majidah; Gutierrez, Olaya Brewer; Agarwal, Amol; Fayad, Lea; Moran, Robert; Alammar, Nuha; Sanaei, Omid; Canto, Marcia I; Singh, Vikesh K; Baron, Todd H; Khashab, Mouen A

2018-05-01

EUS-guided gastroenterostomy (EUS-GE) is a developing modality in the management of gastric outlet obstruction (GOO) with several technical approaches, including the direct and balloon-assisted techniques. The aim of this study was to compare the direct with the balloon-assisted modality while further defining the role of EUS-GE in GOO. This multicenter, retrospective study involved consecutive patients who underwent EUS-GE with the direct or balloon-assisted technique for GOO (January 2014 to October 2016). The primary outcome was technical success. Secondary outcomes were success (ability to tolerate at least a full fluid diet), procedure time, and rate/severity of adverse events (AEs). A total of 74 patients (44.6% women; mean age 63.0 ± 11.7 years) underwent EUS-GE for GOO (direct gastroenterostomy, n = 52; balloon-assisted gastroenterostomy, n = 22). GOO was of malignant and benign etiology in 66.2% and 33.8% of patients, respectively. Technical success was achieved in 94.2% of the direct and 90.9% of the balloon-assisted approach (P = .63). Mean procedure time was shorter with the direct technique (35.7 ± 32.1 minutes vs 89.9 ± 33.3 minutes, P < .001). The clinical success rate was 92.3% for the direct technique and 90.9% for the balloon-assisted modality (P = 1.00), with a mean time to oral intake of 1.32 ± 2.76 days. The AE rate was 6.8% with only 1 severe AE noted. Rate of AEs, postprocedure length of stay, need for reintervention, and survival were similar between the 2 groups. EUS-GE is effective and safe in the management of GOO. The direct technique may be the preferred method given its shorter procedure time when compared with the balloon-assisted approach. Prospective trials are needed to confirm these findings. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Effective Classroom Demonstration of Soil Reinforcing Techniques.

ERIC Educational Resources Information Center

Williams, John Wharton; Fox, Dennis James

1986-01-01

Presents a model for demonstrating soil mass stabilization. Explains how this approach can assist students in understanding the various types of soil reinforcement techniques, their relative contribution to increased soil strength, and some of their limitations. A working drawing of the model and directives for construction are included. (ML)

A Streamlined Molecular Biology Module for Undergraduate Biochemistry Labs

ERIC Educational Resources Information Center

Muth, Gregory W.; Chihade, Joseph W.

2008-01-01

Site-directed mutagenesis and other molecular biology techniques, including plasmid manipulation and restriction analysis, are commonly used tools in the biochemistry research laboratory. In redesigning our biochemistry lab curricula, we sought to integrate these techniques into a term-long, project-based course. In the module presented here,…

An image compression survey and algorithm switching based on scene activity

NASA Technical Reports Server (NTRS)

Hart, M. M.

1985-01-01

Data compression techniques are presented. A description of these techniques is provided along with a performance evaluation. The complexity of the hardware resulting from their implementation is also addressed. The compression effect on channel distortion and the applicability of these algorithms to real-time processing are presented. Also included is a proposed new direction for an adaptive compression technique for real-time processing.

Modeling the Performance of Direct-Detection Doppler Lidar Systems in Real Atmospheres

NASA Technical Reports Server (NTRS)

McGill, Matthew J.; Hart, William D.; McKay, Jack A.; Spinhirne, James D.

1999-01-01

Previous modeling of the performance of spaceborne direct-detection Doppler lidar systems has assumed extremely idealized atmospheric models. Here we develop a technique for modeling the performance of these systems in a more realistic atmosphere, based on actual airborne lidar observations. The resulting atmospheric model contains cloud and aerosol variability that is absent in other simulations of spaceborne Doppler lidar instruments. To produce a realistic simulation of daytime performance, we include solar radiance values that are based on actual measurements and are allowed to vary as the viewing scene changes. Simulations are performed for two types of direct-detection Doppler lidar systems: the double-edge and the multi-channel techniques. Both systems were optimized to measure winds from Rayleigh backscatter at 355 nm. Simulations show that the measurement uncertainty during daytime is degraded by only about 10-20% compared to nighttime performance, provided a proper solar filter is included in the instrument design.

Direct Wafer Bonding and Its Application to Waveguide Optical Isolators

PubMed Central

Mizumoto, Tetsuya; Shoji, Yuya; Takei, Ryohei

2012-01-01

This paper reviews the direct bonding technique focusing on the waveguide optical isolator application. A surface activated direct bonding technique is a powerful tool to realize a tight contact between dissimilar materials. This technique has the potential advantage that dissimilar materials are bonded at low temperature, which enables one to avoid the issue associated with the difference in thermal expansion. Using this technique, a magneto-optic garnet is successfully bonded on silicon, III-V compound semiconductors and LiNbO3. As an application of this technique, waveguide optical isolators are investigated including an interferometric waveguide optical isolator and a semileaky waveguide optical isolator. The interferometric waveguide optical isolator that uses nonreciprocal phase shift is applicable to a variety of waveguide platforms. The low refractive index of buried oxide layer in a silicon-on-insulator (SOI) waveguide enhances the magneto-optic phase shift, which contributes to the size reduction of the isolator. A semileaky waveguide optical isolator has the advantage of large fabrication-tolerance as well as a wide operation wavelength range. PMID:28817020

Development of high temperature fasteners using directionally solidified eutectic alloys

NASA Technical Reports Server (NTRS)

George, F. D.

1972-01-01

The suitability of the eutectics for high temperature fasteners was investigated. Material properties were determined as a function of temperature, and included shear parallel and perpendicular to the growth direction and torsion parallel to it. Techniques for fabricating typical fastener shapes included grinding, creep forming, and direct casting. Both lamellar Ni3Al-Ni3Nb and fibrous (Co,Cr,Al)-(Cr,Co)7C3 alloys showed promise as candidate materials for high temperature fastener applications. A brief evaluation of the performance of the best fabricated fastener design was made.

Adapting line integral convolution for fabricating artistic virtual environment

NASA Astrophysics Data System (ADS)

Lee, Jiunn-Shyan; Wang, Chung-Ming

2003-04-01

Vector field occurs not only extensively in scientific applications but also in treasured art such as sculptures and paintings. Artist depicts our natural environment stressing valued directional feature besides color and shape information. Line integral convolution (LIC), developed for imaging vector field in scientific visualization, has potential of producing directional image. In this paper we present several techniques of exploring LIC techniques to generate impressionistic images forming artistic virtual environment. We take advantage of directional information given by a photograph, and incorporate many investigations to the work including non-photorealistic shading technique and statistical detail control. In particular, the non-photorealistic shading technique blends cool and warm colors into the photograph to imitate artists painting convention. Besides, we adopt statistical technique controlling integral length according to image variance to preserve details. Furthermore, we also propose method for generating a series of mip-maps, which revealing constant strokes under multi-resolution viewing and achieving frame coherence in an interactive walkthrough system. The experimental results show merits of emulating satisfyingly and computing efficiently, as a consequence, relying on the proposed technique successfully fabricates a wide category of non-photorealistic rendering (NPR) application such as interactive virtual environment with artistic perception.

Efficient implementation of real-time programs under the VAX/VMS operating system

NASA Technical Reports Server (NTRS)

Johnson, S. C.

1985-01-01

Techniques for writing efficient real-time programs under the VAX/VMS oprating system are presented. Basic operations are presented for executing at real-time priority and for avoiding needlless processing delays. A highly efficient technique for accessing physical devices by mapping to the input/output space and accessing the device registrs directly is described. To illustrate the application of the technique, examples are included of different uses of the technique on three devices in the Langley Avionics Integration Research Lab (AIRLAB): the KW11-K dual programmable real-time clock, the Parallel Communications Link (PCL11-B) communication system, and the Datacom Synchronization Network. Timing data are included to demonstrate the performance improvements realized with these applications of the technique.

Ministerial Directive No. 1072, June 1985.

PubMed

1988-01-01

This Directive contains nonmandatory guidelines and recommendations for in vitro fertilization and embryo transfer in Chile. The Guidelines are based on the assumption that the constitutional guarantee of the right of the child to be born includes the right to procreate. They set forth the medical reasons for the use of these assisted reproduction techniques, procedures to be followed by institutions applying these techniques, technical facilities, qualifications of medical staff, and the manner in which records are kept. They recommend the mandatory appointment of an Ethics Committee and the obligation to advise couples using these techniques. They also recommend the requirement that all normal and fertilized ovules be returned to the mother and not stored or used for research. full text

Diagnostic techniques for measurement of aerodynamic noise in free field and reverberant environment of wind tunnels

NASA Technical Reports Server (NTRS)

El-Sum, H. M. A.; Mawardi, O. K.

1973-01-01

Techniques for studying aerodynamic noise generating mechanisms without disturbing the flow in a free field, and in the reverberation environment of the ARC wind tunnel were investigated along with the design and testing of an acoustic antenna with an electronic steering control. The acoustic characteristics of turbojet as a noise source, detection of direct sound from a source in a reverberant background, optical diagnostic methods, and the design characteristics of a high directivity acoustic antenna. Recommendations for further studies are included.

Background and survey of bioreplication techniques.

PubMed

Pulsifer, Drew Patrick; Lakhtakia, Akhlesh

2011-09-01

Bioreplication is the direct reproduction of a biological structure in order to realize at least one specific functionality. Current bioreplication techniques include the sol-gel technique, atomic layer deposition, physical vapor deposition, and imprint lithography and casting. The combined use of a focused ion beam and a scanning electron microscope could develop into a bioreplication technique as well. Some of these techniques are more suitable for reproducing surface features, others for bulk three-dimensional structures. Industrial upscaling appears possible only for imprint lithography and casting (which can be replaced by stamping).

Information Landscaping: Information Mapping, Charting, Querying and Reporting Techniques for Total Quality Knowledge Management.

ERIC Educational Resources Information Center

Tsai, Bor-sheng

2003-01-01

Total quality management and knowledge management are merged and used as a conceptual model to direct and develop information landscaping techniques through the coordination of information mapping, charting, querying, and reporting. Goals included: merge citation analysis and data mining, and apply data visualization and information architecture…

Measurement Techniques for Transmit Source Clock Jitter for Weak Serial RF Links

NASA Technical Reports Server (NTRS)

Lansdowne, Chatwin A.; Schlesinger, Adam M.

2010-01-01

Techniques for filtering clock jitter measurements are developed, in the context of controlling data modulation jitter on an RF carrier to accommodate low signal-to-noise ratio thresholds of high-performance error correction codes. Measurement artifacts from sampling are considered, and a tutorial on interpretation of direct readings is included.

Rapid prototyping--when virtual meets reality.

PubMed

Beguma, Zubeda; Chhedat, Pratik

2014-01-01

Rapid prototyping (RP) describes the customized production of solid models using 3D computer data. Over the past decade, advances in RP have continued to evolve, resulting in the development of new techniques that have been applied to the fabrication of various prostheses. RP fabrication technologies include stereolithography (SLA), fused deposition modeling (FDM), computer numerical controlled (CNC) milling, and, more recently, selective laser sintering (SLS). The applications of RP techniques for dentistry include wax pattern fabrication for dental prostheses, dental (facial) prostheses mold (shell) fabrication, and removable dental prostheses framework fabrication. In the past, a physical plastic shape of the removable partial denture (RPD) framework was produced using an RP machine, and then used as a sacrificial pattern. Yet with the advent of the selective laser melting (SLM) technique, RPD metal frameworks can be directly fabricated, thereby omitting the casting stage. This new approach can also generate the wax pattern for facial prostheses directly, thereby reducing labor-intensive laboratory procedures. Many people stand to benefit from these new RP techniques for producing various forms of dental prostheses, which in the near future could transform traditional prosthodontic practices.

A Cost Analysis of Colonoscopy using Microcosting and Time-and-motion Techniques

PubMed Central

Ness, Reid M.; Stiles, Renée A.; Shintani, Ayumi K.; Dittus, Robert S.

2007-01-01

Background The cost of an individual colonoscopy is an important determinant of the overall cost and cost-effectiveness of colorectal cancer screening. Published cost estimates vary widely and typically report institutional costs derived from gross-costing methods. Objective Perform a cost analysis of colonoscopy using micro-costing and time-and-motion techniques to determine the total societal cost of colonoscopy, which includes direct health care costs as well as direct non-health care costs and costs related to patients’ time. The design is prospective cohort. The participants were 276 contacted, eligible patients who underwent colonoscopy between July 2001 and June 2002, at either a Veterans’ Affairs Medical Center or a University Hospital in the Southeastern United States. Major results The median direct health care cost for colonoscopy was $379 (25%, 75%; $343, $433). The median direct non-health care and patient time costs were $226 (25%, 75%; $187, $323) and $274 (25%, 75%; $186, $368), respectively. The median total societal cost of colonoscopy was $923 (25%, 75%; $805, $1047). The median direct health care, direct non-health care, patient time costs, and total costs at the VA were $391, $288, $274, and $958, respectively; analogous costs at the University Hospital were $376, $189, $368, and $905, respectively. Conclusion Microcosting techniques and time-and-motion studies can produce accurate, detailed cost estimates for complex medical interventions. Cost estimates that inform health policy decisions or cost-effectiveness analyses should use total costs from the societal perspective. Societal cost estimates, which include patient and caregiver time costs, may affect colonoscopy screening rates. PMID:17665271

Waste Printed Circuit Board (PCB) Recycling Techniques.

PubMed

Ning, Chao; Lin, Carol Sze Ki; Hui, David Chi Wai; McKay, Gordon

2017-04-01

With the development of technologies and the change of consumer attitudes, the amount of waste electrical and electronic equipment (WEEE) is increasing annually. As the core part of WEEE, the waste printed circuit board (WPCB) is a dangerous waste but at the same time a rich resource for various kinds of materials. In this work, various WPCB treatment methods as well as WPCB recycling techniques divided into direct treatment (landfill and incineration), primitive recycling technology (pyrometallurgy, hydrometallurgy, biometallurgy and primitive full recovery of NMF-non metallic fraction), and advanced recycling technology (mechanical separation, direct use and modification of NMF) are reviewed and analyzed based on their advantages and disadvantages. Also, the evaluation criteria are discussed including economic, environmental, and gate-to-market ability. This review indicates the future research direction of WPCB recycling should focus on a combination of several techniques or in series recycling to maximize the benefits of process.

The Rhizosphere

ERIC Educational Resources Information Center

Feiro, Arthur D.

1978-01-01

The rhizosphere is the area directly surrounding the roots of a plant and an area of tremendous microbial growth. This article described techniques for studying this soil biome. Illustrations are included. (MA)

In vivo correlation mapping microscopy

NASA Astrophysics Data System (ADS)

McGrath, James; Alexandrov, Sergey; Owens, Peter; Subhash, Hrebesh; Leahy, Martin

2016-04-01

To facilitate regular assessment of the microcirculation in vivo, noninvasive imaging techniques such as nailfold capillaroscopy are required in clinics. Recently, a correlation mapping technique has been applied to optical coherence tomography (OCT), which extends the capabilities of OCT to microcirculation morphology imaging. This technique, known as correlation mapping optical coherence tomography, has been shown to extract parameters, such as capillary density and vessel diameter, and key clinical markers associated with early changes in microvascular diseases. However, OCT has limited spatial resolution in both the transverse and depth directions. Here, we extend this correlation mapping technique to other microscopy modalities, including confocal microscopy, and take advantage of the higher spatial resolution offered by these modalities. The technique is achieved as a processing step on microscopy images and does not require any modification to the microscope hardware. Results are presented which show that this correlation mapping microscopy technique can extend the capabilities of conventional microscopy to enable mapping of vascular networks in vivo with high spatial resolution in both the transverse and depth directions.

How Exemplary Inpatient Teaching Physicians Foster Clinical Reasoning.

PubMed

Houchens, Nathan; Harrod, Molly; Fowler, Karen E; Moody, Stephanie; Saint, Sanjay

2017-09-01

Clinical reasoning is a crucial component of training in health professions. These cognitive skills are necessary to provide quality care and avoid diagnostic error. Much previous literature has focused on teaching clinical reasoning in nonclinical environments and does not include learner reflections. The authors sought to explore, through multiple perspectives including learners, techniques used by exemplary inpatient clinician-educators for explicitly cultivating clinical reasoning. The authors conducted (2014-2015) a multisite, exploratory qualitative study examining how excellent clinician-educators foster clinical reasoning during general medicine rounds. This was accomplished through interviews of educators, focus group discussions with learners, and direct observations of clinical teaching. The authors reviewed field notes and transcripts using techniques of thematic analysis. Twelve clinician-educators, 57 current learners, and 26 former learners participated in observations and interviews. The techniques and behaviors of educators were categorized into 4 themes, including 1) emphasizing organization and prioritization, 2) accessing prior knowledge, 3) thinking aloud, and 4) analyzing the literature. The findings of this comprehensive study both confirm strategies found in previous literature and provide novel approaches. This is the first study to incorporate the perspectives of learners. Educators' techniques and behaviors, identified through direct observation and supported by reflections from the entire team, can inform best practices for the teaching of clinical reasoning. Copyright © 2017 Elsevier Inc. All rights reserved.

An iterative analytical technique for the design of interplanetary direct transfer trajectories including perturbations

NASA Astrophysics Data System (ADS)

Parvathi, S. P.; Ramanan, R. V.

2018-06-01

An iterative analytical trajectory design technique that includes perturbations in the departure phase of the interplanetary orbiter missions is proposed. The perturbations such as non-spherical gravity of Earth and the third body perturbations due to Sun and Moon are included in the analytical design process. In the design process, first the design is obtained using the iterative patched conic technique without including the perturbations and then modified to include the perturbations. The modification is based on, (i) backward analytical propagation of the state vector obtained from the iterative patched conic technique at the sphere of influence by including the perturbations, and (ii) quantification of deviations in the orbital elements at periapsis of the departure hyperbolic orbit. The orbital elements at the sphere of influence are changed to nullify the deviations at the periapsis. The analytical backward propagation is carried out using the linear approximation technique. The new analytical design technique, named as biased iterative patched conic technique, does not depend upon numerical integration and all computations are carried out using closed form expressions. The improved design is very close to the numerical design. The design analysis using the proposed technique provides a realistic insight into the mission aspects. Also, the proposed design is an excellent initial guess for numerical refinement and helps arrive at the four distinct design options for a given opportunity.

Evaluation of eating and rumination behaviour in cows using a noseband pressure sensor

PubMed Central

2013-01-01

Background An automated technique for recording eating and rumination behaviour was evaluated in ten lactating Brown Swiss cows by comparing data obtained from a pressure sensor with data obtained via direct observation over a 24-hour period. The recording device involved a pressure sensor integrated in the noseband of a halter. The analysed variables included number and duration of individual rumination, eating and resting phases, total daily length of these phases and number of cuds chewed per day. Results Eating and rumination phases were readily differentiated based on characteristic pressure profiles. Chewing movements during rumination were regular and generated regular waveforms with uniform amplitudes, whereas eating generated irregular waveforms with variable amplitudes. There was complete or almost complete agreement and no significant differences between data obtained via direct observation and pressure sensor technique. Both methods yielded an average of 16 daily eating phases with a mean duration of 28.3 minutes. Total time spent eating was 445.0 minutes for direct observation and 445.4 minutes for the pressure sensor technique. Both techniques recorded an average of 13.3 rumination phases with a mean duration of 30.3 (direct observation) and of 30.2 (pressure sensor) minutes. Total time spent ruminating per day, number of cuds per day and chewing cycles per cud were 389.3 and 388.3 minutes, 410.1 and 410.0 and 60.0 and 60.3 for direct observation and pressure sensor technique, respectively. There was a significant difference between the two methods with respect to mean number of chewing cycles per day (24′669, direct observation vs. 24′751, pressure sensor, P < 0.05, paired t-test). There were strong correlations between the two recording methods with correlation coefficients ranging from 0.98 to 1.00. Conclusions The results confirmed that measurements of eating and rumination variables obtained via the pressure sensor technique are in excellent agreement with data obtained via direct observation. PMID:23941142

3D direct writing fabrication of electrodes for electrochemical storage devices

NASA Astrophysics Data System (ADS)

Wei, Min; Zhang, Feng; Wang, Wei; Alexandridis, Paschalis; Zhou, Chi; Wu, Gang

2017-06-01

Among different printing techniques, direct ink writing is commonly used to fabricate 3D battery and supercapacitor electrodes. The major advantages of using the direct ink writing include effectively building 3D structure for energy storage devices and providing higher power density and higher energy density than traditional techniques due to the increased surface area of electrode. Nevertheless, direct ink writing has high standards for the printing inks, which requires high viscosity, high yield stress under shear and compression, and well-controlled viscoelasticity. Recently, a number of 3D-printed energy storage devices have been reported, and it is very important to understand the printing process and the ink preparation process for further material design and technology development. We discussed current progress of direct ink writing technologies by using various electrode materials including carbon nanotube-based material, graphene-based material, LTO (Li4Ti5O12), LFP (LiFePO4), LiMn1-xFexPO4, and Zn-based metallic oxide. Based on achieve electrochemical performance, these 3D-printed devices deliver performance comparable to the energy storage device fabricated using traditional methods still leaving large room for further improvement. Finally, perspectives are provided on the potential future direction of 3D printing for all solid-state electrochemical energy storage devices.

The Random Response Technique as an Indicator of Questionnaire Item Social Desirability/Personal Sensitivity.

ERIC Educational Resources Information Center

Crino, Michael D.; And Others

1985-01-01

The random response technique was compared to a direct questionnaire, administered to college students, to investigate whether or not the responses predicted the social desirability of the item. Results suggest support for the hypothesis. A 33-item version of the Marlowe-Crowne Social Desirability Scale which was used is included. (GDC)

Accuracy of trace element determinations in alternate fuels

NASA Technical Reports Server (NTRS)

Greenbauer-Seng, L. A.

1980-01-01

A review of the techniques used at Lewis Research Center (LeRC) in trace metals analysis is presented, including the results of Atomic Absorption Spectrometry and DC Arc Emission Spectrometry of blank levels and recovery experiments for several metals. The design of an Interlaboratory Study conducted by LeRC is presented. Several factors were investigated, including: laboratory, analytical technique, fuel type, concentration, and ashing additive. Conclusions drawn from the statistical analysis will help direct research efforts toward those areas most responsible for the poor interlaboratory analytical results.

A micromotor based on polymer single crystals and nanoparticles: toward functional versatility

NASA Astrophysics Data System (ADS)

Liu, Mei; Liu, Limei; Gao, Wenlong; Su, Miaoda; Ge, Ya; Shi, Lili; Zhang, Hui; Dong, Bin; Li, Christopher Y.

2014-07-01

We report a multifunctional micromotor fabricated by the self-assembly technique using multifunctional materials, i.e. polymer single crystals and nanoparticles, as basic building blocks. Not only can this micromotor achieve autonomous and directed movement, it also possesses unprecedented functions, including enzymatic degradation-induced micromotor disassembly, sustained release and molecular detection.We report a multifunctional micromotor fabricated by the self-assembly technique using multifunctional materials, i.e. polymer single crystals and nanoparticles, as basic building blocks. Not only can this micromotor achieve autonomous and directed movement, it also possesses unprecedented functions, including enzymatic degradation-induced micromotor disassembly, sustained release and molecular detection. Electronic supplementary information (ESI) available: Experimental section, Fig. S1-S8 and Video S1-S4. See DOI: 10.1039/c4nr02593h

Range estimation techniques in single-station thunderstorm warning sensors based upon gated, wideband, magnetic direction finder technology

NASA Technical Reports Server (NTRS)

Pifer, Alburt E.; Hiscox, William L.; Cummins, Kenneth L.; Neumann, William T.

1991-01-01

Gated, wideband, magnetic direction finders (DFs) were originally designed to measure the bearing of cloud-to-ground lightning relative to the sensor. A recent addition to this device uses proprietary waveform discrimination logic to select return stroke signatures and certain range dependent features in the waveform to provide an estimate of range of flashes within 50 kms. The enhanced ranging techniques are discussed which were designed and developed for use in single station thunderstorm warning sensor. Included are the results of on-going evaluations being conducted under a variety of meteorological and geographic conditions.

Panel Discussion: New Directions in Human Reliability Analysis for Oil & Gas, Cybersecurity, Nuclear, and Aviation

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

Harold S. Blackman; Ronald Boring; Julie L. Marble

This panel will discuss what new directions are necessary to maximize the usefulness of HRA techniques across different areas of application. HRA has long been a part of Probabilistic Risk Assessment in the nuclear industry as it offers a superior standard for risk-based decision-making. These techniques are continuing to be adopted by other industries including oil & gas, cybersecurity, nuclear, and aviation. Each participant will present his or her ideas concerning industry needs followed by a discussion about what research is needed and the necessity to achieve cross industry collaboration.

Direct labeling and visualization of blood vessels with lipophilic carbocyanine dye DiI

PubMed Central

Li, Yiwen; Song, Ying; Zhao, Lian; Gaidosh, Gabriel; Laties, Alan M; Wen, Rong

2009-01-01

We describe a protocol to rapidly and reliably visualize blood vessels in experimental animals. Blood vessels are directly labeled by cardiac perfusion using a specially formulated aqueous solution containing 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI), a lipophilic carbocyanine dye, which incorporates into endothelial cell membranes upon contact. By lateral diffusion, DiI also stains membrane structures, including angiogenic sprouts and pseudopodial processes that are not in direct contact. Tissues can be immediately examined by conventional and confocal fluorescence microscopy. High-quality serial optical sections using confocal microscopy are obtainable from thick tissue sections, especially at low magnification, for three-dimensional reconstruction. It takes less than 1 h to stain the vasculature in a whole animal. Compared with alternative techniques to visualize blood vessels, including space-occupying materials such as India ink or fluorescent dye-conjugated dextran, the corrosion casting technique, endothelial cell-specific markers and lectins, the present method simplifies the visualization of blood vessels and data analysis. PMID:18846097

Greater Success of Primary Fascial Closure of the Open Abdomen: A Retrospective Study Analyzing Applied Surgical Techniques, Success of Fascial Closure, and Variables Affecting the Results.

PubMed

Kääriäinen, M; Kuuskeri, M; Helminen, M; Kuokkanen, H

2017-06-01

The open abdomen technique is a standard procedure in the treatment of intra-abdominal catastrophe. Achieving primary abdominal closure within the initial hospitalization is a main objective. This study aimed to analyze the success of closure rate and the effect of negative pressure wound therapy, mesh-mediated medial traction, and component separation on the results. We present the treatment algorithm used in our institution in open abdomen situations based on these findings. Open abdomen patients (n = 61) treated in Tampere University Hospital from May 2005 until October 2013 were included in the study. Patient characteristics, treatment prior to closure, closure technique, and results were retrospectively collected and analyzed. The first group included patients in whom direct or bridged fascial closure was achieved, and the second group included those in whom only the skin was closed or a free skin graft was used. Background variables and variables related to surgery were compared between groups. Most of the open abdomen patients (72.1%) underwent fascial defect repair during the primary hospitalization, and 70.5% of them underwent direct fascial closure. Negative pressure wound therapy was used as a temporary closure method for 86.9% of the patients. Negative pressure wound therapy combined with mesh-mediated medial traction resulted in the shortest open abdomen time (p = 0.039) and the highest fascial repair rate (p = 0.000) compared to negative pressure wound therapy only or no negative pressure wound therapy. The component separation technique was used for 11 patients; direct fascial closure was achieved in 5 and fascial repair by bridging the defect with mesh was achieved in 6. A total of 8 of 37 (21.6%) patients with mesh repair had a mesh infection. The negative pressure wound therapy combined with mesh-mediated medial traction promotes definitive fascial closure with a high closure rate and a shortened open abdomen time. The component separation technique can be used to facilitate fascial repair but it does not guarantee direct fascial closure in open abdomen patients.

Ab initio quantum direct dynamics simulations of ultrafast photochemistry with Multiconfigurational Ehrenfest approach

NASA Astrophysics Data System (ADS)

Makhov, Dmitry V.; Symonds, Christopher; Fernandez-Alberti, Sebastian; Shalashilin, Dmitrii V.

2017-08-01

The Multiconfigurational Ehrenfest (MCE) method is a quantum dynamics technique which allows treatment of a large number of quantum nuclear degrees of freedom. This paper presents a review of MCE and its recent applications, providing a summary of the formalisms, including its ab initio direct dynamics versions and also giving a summary of recent results. Firstly, we describe the Multiconfigurational Ehrenfest version 2 (MCEv2) method and its applicability to direct dynamics and report new calculations which show that the approach converges to the exact result in model systems with tens of degrees of freedom. Secondly, we review previous ;on the fly; ab initio Multiple Cloning (AIMC-MCE) MCE dynamics results obtained for systems of a similar size, in which the calculations treat every electron and every nucleus of a polyatomic molecule on a fully quantum basis. We also review the Time Dependent Diabatic Basis (TDDB) version of the technique and give an example of its application. We summarise the details of the sampling techniques and interpolations used for calculation of the matrix elements, which make our approach efficient. Future directions of work are outlined.

The Genetic Programming of Industrial Microorganisms.

ERIC Educational Resources Information Center

Hopwood, David A.

1981-01-01

Traces the development of the field of industrial microbial genetics, describing a range of techniques for genetic programing. Includes a discussion of site-directed mutagenesis, protoplast fusion, and recombinant DNA manipulations. (CS)

A novel pretreatment method combining sealing technique with direct injection technique applied for improving biosafety.

PubMed

Wang, Xinyu; Gao, Jing-Lin; Du, Chaohui; An, Jing; Li, MengJiao; Ma, Haiyan; Zhang, Lina; Jiang, Ye

2017-01-01

People today have a stronger interest in the risk of biosafety in clinical bioanalysis. A safe, simple, effective method of preparation is needed urgently. To improve biosafety of clinical analysis, we used antiviral drugs of adefovir and tenofovir as model drugs and developed a safe pretreatment method combining sealing technique with direct injection technique. The inter- and intraday precision (RSD %) of the method were <4%, and the extraction recoveries ranged from 99.4 to 100.7%. Meanwhile, the results showed that standard solution could be used to prepare calibration curve instead of spiking plasma, acquiring more accuracy result. Compared with traditional methods, the novel method not only improved biosecurity of the pretreatment method significantly, but also achieved several advantages including higher precision, favorable sensitivity and satisfactory recovery. With these highly practical and desirable characteristics, the novel method may become a feasible platform in bioanalysis.

Transgender Phonosurgery: A Systematic Review and Meta-analysis.

PubMed

Song, Tara Elena; Jiang, Nancy

2017-05-01

Objectives Different surgical techniques have been described in the literature to increase vocal pitch. The purpose of this study is to systematically review these surgeries and perform a meta-analysis to determine which technique increases pitch the most. Data Sources CINAHL, Cochrane, Embase, Medline, PubMed, and Science Direct. Review Methods A systematic review and meta-analysis of the literature was performed using the CINAHL, Cochrane, Embase, Medline, PubMed, and Science Direct databases. Studies were eligible for inclusion if they evaluated pitch-elevating phonosurgical techniques in live humans and performed pre- and postoperative acoustic analysis. Data were gathered regarding surgical technique, pre- and postoperative fundamental frequencies, perioperative care measures, and complications. Results Twenty-nine studies were identified. After applying inclusion and exclusion criteria, a total of 13 studies were included in the meta-analysis. Mechanisms of pitch elevation included increasing vocal cord tension (cricothyroid approximation), shortening the vocal cord length (cold knife glottoplasty, laser-shortening glottoplasty), and decreasing mass (laser reduction glottoplasty). The most common interventions were shortening techniques and cricothyroid approximation (6 studies each). The largest increase in fundamental frequency was seen with techniques that shortened the vocal cords. Preoperative speech therapy, postoperative voice rest, and reporting of patient satisfaction were inconsistent. Many of the studies were limited by low power and short length of follow-up. Conclusions Multiple techniques for elevation of vocal pitch exist, but vocal cord shortening procedures appear to result in the largest increase in fundamental frequency.

Combustion method for assay of biological materials labeled with carbon-14 or tritium, or double-labeled

NASA Technical Reports Server (NTRS)

Huebner, L. G.; Kisieleski, W. E.

1969-01-01

Dry catalytic combustion at high temperatures is used for assaying biological materials labeled carbon-14 and tritium, or double-labeled. A modified oxygen-flask technique is combined with standard vacuum-line techniques and includes convenience of direct in-vial collection of final combustion products, giving quantitative recovery of tritium and carbon-14.

Long-term prosthetic aftercare of direct vs. indirect attachment incorporation techniques to mandibular implant-supported overdenture.

PubMed

Nissan, Joseph; Oz-Ari, Beni; Gross, Ora; Ghelfan, Oded; Chaushu, Gavriel

2011-06-01

The aim of this long-term study was to compare the need for prosthetic aftercare of direct vs. indirect attachment incorporation techniques to mandibular implant-supported overdenture. Forty-five consecutive patients were included (130 implants were placed). Treatment was randomly allocated, resulting in 22 patients (group A) to be treated with direct ball attachment incorporation and 23 patients (group B) to be treated with indirect ball attachment incorporation. All patients were treated by experienced oral-maxillofacial surgeons/periodontists and experienced prosthodontists/residents. From the first day that the patients visited the clinic up to 20 years after the first treatment session, all surgical or prosthetic therapeutic interventions were recorded. The recorded data for the present study included the number of aftercare visits and dental treatment received (pressure sores relieve, liner changes due to loss of retention and attachment replacement due to wear). The mean follow-up was 93±57 months. No implants were lost. Statistical analysis revealed a statistically significantly (P<0.001) greater need for prosthetic interventions in group B vs. group A. The mean number of visits dedicated to - pressure sores relieve (7.04±1.4 vs. 3.63±0.84); liner exchange due to loss of retention (3.6±1.3 vs. 1.09±1.06) was significantly higher in group B. Attachment replacement due to wear occurred only in group B (11/23 - 47.8%). The direct technique for attachment incorporation in mandibular implant-supported overdentures using ball attachments is superior to the indirect technique from the aftercare perspective during a long-term evaluation period. © 2010 John Wiley & Sons A/S.

NASA and energy

NASA Technical Reports Server (NTRS)

1974-01-01

NASA technology contributions to create energy sources include direct solar heating and cooling systems, wind generation of electricity, solar thermal energy turbine drives, solar cells, and techniques for locating, producing, and collecting organic materials for conversion into fuel.

Optical micromanipulation of active cells with minimal perturbations: direct and indirect pushing.

PubMed

Wang, Chenlu; Chowdhury, Sagar; Gupta, Satyandra K; Losert, Wolfgang

2013-04-01

The challenge to wide application of optical tweezers in biological micromanipulation is the photodamage caused by high-intensity laser exposure to the manipulated living systems. While direct exposure to infrared lasers is less likely to kill cells, it can affect cell behavior and signaling. Pushing cells with optically trapped objects has been introduced as a less invasive alternative, but the technique includes some exposure of the biological object to parts of the optical tweezer beam. To keep the cells farther away from the laser, we introduce an indirect pushing-based technique for noninvasive manipulation of sensitive cells. We compare how cells respond to three manipulation approaches: direct manipulation, pushing, and indirect pushing. We find that indirect manipulation techniques lessen the impact of manipulation on cell behavior. Cell survival increases, as does the ability of cells to maintain shape and wiggle. Our experiments also demonstrate that indirect pushing allows cell-cell contacts to be formed in a controllable way, while retaining the ability of cells to change shape and move.

Comparison of digital signal-signal beat interference compensation techniques in direct-detection subcarrier modulation systems.

PubMed

Li, Zhe; Erkilinc, M Sezer; Galdino, Lidia; Shi, Kai; Thomsen, Benn C; Bayvel, Polina; Killey, Robert I

2016-12-12

Single-polarization direct-detection transceivers may offer advantages compared to digital coherent technology for some metro, back-haul, access and inter-data center applications since they offer low-cost and complexity solutions. However, a direct-detection receiver introduces nonlinearity upon photo detection, since it is a square-law device, which results in signal distortion due to signal-signal beat interference (SSBI). Consequently, it is desirable to develop effective and low-cost SSBI compensation techniques to improve the performance of such transceivers. In this paper, we compare the performance of a number of recently proposed digital signal processing-based SSBI compensation schemes, including the use of single- and two-stage linearization filters, an iterative linearization filter and a SSBI estimation and cancellation technique. Their performance is assessed experimentally using a 7 × 25 Gb/s wavelength division multiplexed (WDM) single-sideband 16-QAM Nyquist-subcarrier modulation system operating at a net information spectral density of 2.3 (b/s)/Hz.

Left Atrial Appendage Closure for Stroke Prevention: Devices, Techniques, and Efficacy.

PubMed

Iskandar, Sandia; Vacek, James; Lavu, Madhav; Lakkireddy, Dhanunjaya

2016-05-01

Left atrial appendage closure can be performed either surgically or percutaneously. Surgical approaches include direct suture, excision and suture, stapling, and clipping. Percutaneous approaches include endocardial, epicardial, and hybrid endocardial-epicardial techniques. Left atrial appendage anatomy is highly variable and complex; therefore, preprocedural imaging is crucial to determine device selection and sizing, which contribute to procedural success and reduction of complications. Currently, the WATCHMAN is the only device that is approved for left atrial appendage closure in the United States. Copyright © 2016 Elsevier Inc. All rights reserved.

A study for hypergolic vapor sensor development

NASA Technical Reports Server (NTRS)

Stetter, J. R.

1977-01-01

The use of an electrochemical technique for MMH and N02 measurement was investigated. Specific MMH and N02 electrochemical sensors were developed. Experimental techniques for preparation, handling, and analysis of hydrazine's vapor mixtures at ppb and ppm levels were developed. Two approaches to N02 instrument design were evaluated including specific adsorption and specific electrochemical reduction. Two approaches to hydrazines monitoring were evaluated including catalytic conversion to N0 with subsequent N0 detection and direct specific electrochemical oxidation. Two engineering prototype MMH/N02 monitors were designed and constructed.

Laser 3D micro-manufacturing

NASA Astrophysics Data System (ADS)

Piqué, Alberto; Auyeung, Raymond C. Y.; Kim, Heungsoo; Charipar, Nicholas A.; Mathews, Scott A.

2016-06-01

Laser-based materials processing techniques are gaining widespread use in micro-manufacturing applications. The use of laser microfabrication techniques enables the processing of micro- and nanostructures from a wide range of materials and geometries without the need for masking and etching steps commonly associated with photolithography. This review aims to describe the broad applications space covered by laser-based micro- and nanoprocessing techniques and the benefits offered by the use of lasers in micro-manufacturing processes. Given their non-lithographic nature, these processes are also referred to as laser direct-write and constitute some of the earliest demonstrations of 3D printing or additive manufacturing at the microscale. As this review will show, the use of lasers enables precise control of the various types of processing steps—from subtractive to additive—over a wide range of scales with an extensive materials palette. Overall, laser-based direct-write techniques offer multiple modes of operation including the removal (via ablative processes) and addition (via photopolymerization or printing) of most classes of materials using the same equipment in many cases. The versatility provided by these multi-function, multi-material and multi-scale laser micro-manufacturing processes cannot be matched by photolithography nor with other direct-write microfabrication techniques and offer unique opportunities for current and future 3D micro-manufacturing applications.

Evaluation of gravimetric techniques to estimate the microvascular filtration coefficient

PubMed Central

Dongaonkar, R. M.; Laine, G. A.; Stewart, R. H.

2011-01-01

Microvascular permeability to water is characterized by the microvascular filtration coefficient (Kf). Conventional gravimetric techniques to estimate Kf rely on data obtained from either transient or steady-state increases in organ weight in response to increases in microvascular pressure. Both techniques result in considerably different estimates and neither account for interstitial fluid storage and lymphatic return. We therefore developed a theoretical framework to evaluate Kf estimation techniques by 1) comparing conventional techniques to a novel technique that includes effects of interstitial fluid storage and lymphatic return, 2) evaluating the ability of conventional techniques to reproduce Kf from simulated gravimetric data generated by a realistic interstitial fluid balance model, 3) analyzing new data collected from rat intestine, and 4) analyzing previously reported data. These approaches revealed that the steady-state gravimetric technique yields estimates that are not directly related to Kf and are in some cases directly proportional to interstitial compliance. However, the transient gravimetric technique yields accurate estimates in some organs, because the typical experimental duration minimizes the effects of interstitial fluid storage and lymphatic return. Furthermore, our analytical framework reveals that the supposed requirement of tying off all draining lymphatic vessels for the transient technique is unnecessary. Finally, our numerical simulations indicate that our comprehensive technique accurately reproduces the value of Kf in all organs, is not confounded by interstitial storage and lymphatic return, and provides corroboration of the estimate from the transient technique. PMID:21346245

Direct access inter-process shared memory

DOEpatents

Brightwell, Ronald B; Pedretti, Kevin; Hudson, Trammell B

2013-10-22

A technique for directly sharing physical memory between processes executing on processor cores is described. The technique includes loading a plurality of processes into the physical memory for execution on a corresponding plurality of processor cores sharing the physical memory. An address space is mapped to each of the processes by populating a first entry in a top level virtual address table for each of the processes. The address space of each of the processes is cross-mapped into each of the processes by populating one or more subsequent entries of the top level virtual address table with the first entry in the top level virtual address table from other processes.

Comparison of numerical techniques for the evaluation of the Doppler broadening functions psi(x,theta) and chi(x,theta)

NASA Technical Reports Server (NTRS)

Canright, R. B., Jr.; Semler, T. T.

1972-01-01

Several approximations to the Doppler broadening functions psi(x, theta) and chi(x, theta) are compared with respect to accuracy and speed of evaluation. A technique, due to A. M. Turning (1943), is shown to be at least as accurate as direct numerical quadrature and somewhat faster than Gaussian quadrature. FORTRAN 4 listings are included.

Position and speed control of brushless DC motors using sensorless techniques and application trends.

PubMed

Gamazo-Real, José Carlos; Vázquez-Sánchez, Ernesto; Gómez-Gil, Jaime

2010-01-01

This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC) motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order) and Artificial Neural Networks.

Object tracking with stereo vision

NASA Technical Reports Server (NTRS)

Huber, Eric

1994-01-01

A real-time active stereo vision system incorporating gaze control and task directed vision is described. Emphasis is placed on object tracking and object size and shape determination. Techniques include motion-centroid tracking, depth tracking, and contour tracking.

The Dot Blot ELISA.

ERIC Educational Resources Information Center

Gerbig, Donald G., Jr.; Fenk, Christopher J.; Goodhart, Amy S.

2000-01-01

Uses two laboratory techniques, Enzyme Linked Immunosorbent Assay (ELISA) and Western Blot, to demonstrate antibody-antigen binding concepts. Includes a list of required materials and directions for the procedure, and makes suggestions for classroom applications. (Contains 13 references.) (YDS)

Laboratory Techniques for the Blind

ERIC Educational Resources Information Center

Tombaugh, Dorothy

1972-01-01

Describes modifications of laboratory procedures for the BSCS Green Version biology, including dissection, microbiology, animal behavior, physiology, biochemistry, and genetics that make the methods suitable for direct experimentation by blind students. Discusses models as substitutes for microscopy. (AL)

Evaluation of three simple direct or indirect carbonyl detection methods for characterization of oxidative modifications of proteins.

PubMed

Vásquez-Garzón, Verónica R; Rouimi, Patrick; Jouanin, Isabelle; Waeg, Georg; Zarkovic, Neven; Villa-Treviño, Saul; Guéraud, Françoise

2012-05-01

Among disruptions induced by oxidative stress, modifications of proteins, particularly irreversible carbonylation, are associated with the development of several diseases, including cardiovascular diseases, neurodegenerative diseases, and cancer. Carbonylation of proteins can occur directly or indirectly through the adduction of lipid oxidation products. In this study, three classical and easy-to-perform techniques to detect direct or indirect carbonylation of proteins were compared. A model protein apomyoglobin and a complex mixture of rat liver cytosolic proteins were exposed to cumene hydroperoxide oxidation or adduction to the lipid peroxidation product 4-hydroxynonenal in order to test direct or indirect carbonylation, respectively. The technique using a specific anti-4-hydroxynonenal-histidine adduct antibody was effective to detect in vitro modification of model apomyoglobin and cytosolic proteins by 4-hydroxynonenal but not by direct carbonylation which was achieved by techniques using biotin-coupled hydrazide or dinitrophenylhydrazine derivatization of carbonyls. Sequential use of these methods enabled the detection of both direct and indirect carbonyl modification in proteins, although constitutively biotinylated proteins were detected by biotin-hydrazide. Although rather classical and efficient, methods for carbonyl detection on proteins in oxidative stress studies may be biased by some artifactual detections and complicated by proteins multimerizations. The use of more and more specific available antibodies is recommended to complete detection of lipid peroxidation product adducts on proteins.

Direct analysis of herbal powders by pipette-tip electrospray ionization mass spectrometry.

PubMed

Wang, Haixing; So, Pui-Kin; Yao, Zhong-Ping

2014-01-27

Conventional electrospray ionization mass spectrometry (ESI-MS) is widely used for analysis of solution samples. The development of solid-substrate ESI-MS allows direct ionization analysis of bulky solid samples. In this study, we developed pipette-tip ESI-MS, a technique that combines pipette tips with syringe and syringe pump, for direct analysis of herbal powders, another common form of samples. We demonstrated that various herbal powder samples, including herbal medicines and food samples, could be readily online extracted and analyzed using this technique. Various powder samples, such as Rhizoma coptidis, lotus plumule, great burdock achene, black pepper, Panax ginseng, roasted coffee beans, Fructus Schisandrae Chinensis and Fructus Schisandrae Sphenantherae, were analyzed using pipette-tip ESI-MS and quality mass spectra with stable and durable signals could be obtained. Both positive and negative ion modes were attempted and various compounds including amino acids, oligosaccharides, glycosides, alkaloids, organic acids, ginosensides, flavonoids and lignans could be detected. Principal component analysis (PCA) based on the acquired mass spectra allowed rapid differentiation of closely related herbal species. Copyright © 2013 Elsevier B.V. All rights reserved.

Advances in contact algorithms and their application to tires

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Tanner, John A.

1988-01-01

Currently used techniques for tire contact analysis are reviewed. Discussion focuses on the different techniques used in modeling frictional forces and the treatment of contact conditions. A status report is presented on a new computational strategy for the modeling and analysis of tires, including the solution of the contact problem. The key elements of the proposed strategy are: (1) use of semianalytic mixed finite elements in which the shell variables are represented by Fourier series in the circumferential direction and piecewise polynomials in the meridional direction; (2) use of perturbed Lagrangian formulation for the determination of the contact area and pressure; and (3) application of multilevel iterative procedures and reduction techniques to generate the response of the tire. Numerical results are presented to demonstrate the effectiveness of a proposed procedure for generating the tire response associated with different Fourier harmonics.

Techniques to Aid DoD Writers in Developing User-Oriented Directives

DTIC Science & Technology

1990-09-01

received from sales of the recovered materials, expenses incurred in this program, the number and costs of projects for environmental improvement and...components for managing acquisition programs. a. Program direction and guidance for ACAT I programs, to include all matters relating to cost , schedule...documented needs and unfunded ownership costs requirements * Operational deficiencies identified must first be Proposed exit criteria tnat must be

Using aspen for artist stretcher frames: adding value through quality service, direct marketing, and careful material selection

Treesearch

Chris Polson

2001-01-01

Aspen wood, when carefully selected and kiln dried, makes excellent stock for artist stretcher frames. Direct marketing techniques including the Internet and word of mouth give access to national markets, providing a more diverse and stable customer base for operations from a rural area. High-quality service, as shown by product performance and rapid order fulfillment...

Local Measurement of Tropospheric HO(x)

NASA Technical Reports Server (NTRS)

Crosley, David R.

1994-01-01

In March of 1992 a workshop sponsored by NASA and NSF was held at SRI International to assess the current ability to measure atmospheric OH and HO2. The measurement techniques reviewed during the workshop for detection of OH included five laser-induced fluorescence schemes, five laser-based adsorption techniques, and four non-laser methods. Six instruments or instrument concepts for HO2 detection, including chemical amplification, conversion to OH with subsequent OH detection, or direct spectroscopic detection of the HO2 were also discussed. The conclusions from the workshop identify several measurement techniques for OH and HO2 that are ready for field tests. These have the ability to measure the radicals with sufficient sensitivity and accuracy to form meaningful comparison with atmospheric model predictions. The workshop conclusions also include recommendations for informal and formal intercomparison protocols.

Measuring situation awareness in emergency settings: a systematic review of tools and outcomes

PubMed Central

Cooper, Simon; Porter, Joanne; Peach, Linda

2014-01-01

Background Nontechnical skills have an impact on health care outcomes and improve patient safety. Situation awareness is core with the view that an understanding of the environment will influence decision-making and performance. This paper reviews and describes indirect and direct measures of situation awareness applicable for emergency settings. Methods Electronic databases and search engines were searched from 1980 to 2010, including CINAHL, Ovid Medline, Pro-Quest, Cochrane, and the search engine, Google Scholar. Access strategies included keyword, author, and journal searches. Publications identified were assessed for relevance, and analyzed and synthesized using Oxford evidence levels and the Critical Appraisal Skills Programme guidelines in order to assess their quality and rigor. Results One hundred and thirteen papers were initially identified, and reduced to 55 following title and abstract review. The final selection included 14 papers drawn from the fields of emergency medicine, intensive care, anesthetics, and surgery. Ten of these discussed four general nontechnical skill measures (including situation awareness) and four incorporated the Situation Awareness Global Assessment Technique. Conclusion A range of direct and indirect techniques for measuring situation awareness is available. In the medical literature, indirect approaches are the most common, with situation awareness measured as part of a nontechnical skills assessment. In simulation-based studies, situation awareness in emergencies tends to be suboptimal, indicating the need for improved training techniques to enhance awareness and improve decision-making. PMID:27147872

Direct characterization of commercial lecithins by easy ambient sonic-spray ionization mass spectrometry.

PubMed

Fernandes, Gabriel D; Alberici, Rosana M; Pereira, Gustavo G; Cabral, Elaine C; Eberlin, Marcos N; Barrera-Arellano, Daniel

2012-12-01

Commercial lecithins are composed mainly of phospholipids and triacylglycerols. The analysis of the commercial lecithins, including their fraction of phospholipids, normally involves laborious and expensive protocols. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to be an efficient technique for the analysis of lipids. Samples of commercial lecithins including standards, refined, deoiled and modified soy lecithin were tested. Characteristic profiles of phosphatidylcholines and triacylglycerols are detected by EASI(+)-MS, whereas EASI(-)-MS provided phosphatidylethanolamines, glycophospholipids and free fatty acids profiles. Acetylated lecithins also displayed characteristic acetylated derivatives. EASI-MS data was also compared to MALDI-MS, and found to display richer compositional information. The industrial process applied to lecithin fabrication was also characterised via typical EASI-MS profiles. EASI-MS both in its positive and negative ion modes offers a direct, fast and efficient technique able to characterise commercial lecithin. Copyright © 2012 Elsevier Ltd. All rights reserved.

Method and device for landing aircraft dependent on runway occupancy time

NASA Technical Reports Server (NTRS)

Ghalebsaz Jeddi, Babak (Inventor)

2012-01-01

A technique for landing aircraft using an aircraft landing accident avoidance device is disclosed. The technique includes determining at least two probability distribution functions; determining a safe lower limit on a separation between a lead aircraft and a trail aircraft on a glide slope to the runway; determining a maximum sustainable safe attempt-to-land rate on the runway based on the safe lower limit and the probability distribution functions; directing the trail aircraft to enter the glide slope with a target separation from the lead aircraft corresponding to the maximum sustainable safe attempt-to-land rate; while the trail aircraft is in the glide slope, determining an actual separation between the lead aircraft and the trail aircraft; and directing the trail aircraft to execute a go-around maneuver if the actual separation approaches the safe lower limit. Probability distribution functions include runway occupancy time, and landing time interval and/or inter-arrival distance.

Improvements in approaches to forecasting and evaluation techniques

NASA Astrophysics Data System (ADS)

Weatherhead, Elizabeth

2014-05-01

The US is embarking on an experiment to make significant and sustained improvements in weather forecasting. The effort stems from a series of community conversations that recognized the rapid advancements in observations, modeling and computing techniques in the academic, governmental and private sectors. The new directions and initial efforts will be summarized, including information on possibilities for international collaboration. Most new projects are scheduled to start in the last half of 2014. Several advancements include ensemble forecasting with global models, and new sharing of computing resources. Newly developed techniques for evaluating weather forecast models will be presented in detail. The approaches use statistical techniques that incorporate pair-wise comparisons of forecasts with observations and account for daily auto-correlation to assess appropriate uncertainty in forecast changes. Some of the new projects allow for international collaboration, particularly on the research components of the projects.

Bench-Top Feasibility Testing of a Novel Percutaneous Renal Access Technique: The Laser Direct Alignment Radiation Reduction Technique (DARRT).

PubMed

Khater, Nazih; Shen, Jim; Arenas, Javier; Keheila, Mohamed; Alsyouf, Muhannad; Martin, Jacob A; Lightfoot, Michelle A; Li, Roger; Olgin, Gaudencio; Smith, Jason C; Baldwin, D Duane

2016-11-01

Traditional techniques for obtaining percutaneous renal access utilize continuous fluoroscopy. In an attempt to minimize radiation exposure, we describe a novel laser direct alignment radiation reduction technique (DARRT) for percutaneous access and test it in a bench-top model. In this randomized-controlled bench-top study, 20 medical personnel obtained renal accesses using both the conventional bullseye technique and the laser DARRT. The primary endpoint was total fluoroscopy time. Secondary endpoints included insertion time, puncture attempts, course corrections, and subjective procedural difficulty. In the laser DARRT, fluoroscopy was used with the C-arm positioned with the laser beam at a 30° angle. The access needle and hub were aligned with the laser beam. Effective caliceal puncture was confirmed with fluoroscopy and direct vision. The Paired samples Wilcoxon signed rank test was used for statistical analysis with significance at p < 0.05. A total of 120 needle placements were recorded. Fluoroscopy time for needle access using the laser DARRT was significantly lower than the bullseye technique in all groups as follows: attendings (7.09 vs 18.51 seconds; p < 0.001), residents (6.55 vs 13.93 seconds; p = 0.001), and medical students (6.69 vs 20.22 seconds; p < 0.001). Students rated the laser DARRT easier to use (2.56 vs 4.89; p < 0.001). No difference was seen in total access time, puncture attempts, or course corrections between techniques. The laser DARRT reduced fluoroscopy time by 63%, compared with the conventional bullseye technique. The least experienced users found the laser DARRT significantly easier to learn. This novel technique is promising and merits additional testing in animal and human models.

Gynecomastia Management: An Evolution and Refinement in Technique at UT Southwestern Medical Center

PubMed Central

Bailey, Steven H.; Guenther, Dax; Constantine, Fadi

2016-01-01

Summary: Gynecomastia is a benign proliferation of male breast glandular tissue. Gynecomastia can affect men at any stage of life. Traditional treatment options involved excisional surgeries with periareolar or T-shaped scars, which can leave more visible scars on the chest. The technique presented represents a technique used by the senior author, which relies on ultrasonic liposuction and pull-through technique to remove breast tissue. A retrospective chart review was performed, including all patients who were treated, from 2000 to 2013 by the senior author, for gynecomastia. A deidentified database was created to record patient characteristics, including age, height, weight, ptosis, stage of gynecomastia, and gynecomastia classification. Surgical approaches, complications, and revisions were also recorded. Our experience includes 75 patients with all grades of gynecomastia from 2000 to 2013. These cases span the evolution of our technique to include direct pull-through excision with ultrasound-assisted liposuction. The distribution of the grades I, II, III, and IV ptosis was 30.6%, 36 %, 22.6%, and 10.6% respectively. There were no complications in this series. Only one patient with grade III ptosis required revision surgery. This technique provides a safe and aesthetically pleasing way to treat gynecomastia with a low need for revision. PMID:27482482

Imaging of respiratory muscles in neuromuscular disease: A review.

PubMed

Harlaar, L; Ciet, P; van der Ploeg, A T; Brusse, E; van der Beek, N A M E; Wielopolski, P A; de Bruijne, M; Tiddens, H A W M; van Doorn, P A

2018-03-01

Respiratory muscle weakness frequently occurs in patients with neuromuscular disease. Measuring respiratory function with standard pulmonary function tests provides information about the contribution of all respiratory muscles, the lungs and airways. Imaging potentially enables the study of different respiratory muscles, including the diaphragm, separately. In this review, we provide an overview of imaging techniques used to study respiratory muscles in neuromuscular disease. We identified 26 studies which included a total of 573 patients with neuromuscular disease. Imaging of respiratory muscles was divided into static and dynamic techniques. Static techniques comprise chest radiography, B-mode (brightness mode) ultrasound, CT and MRI, and are used to assess the position and thickness of the diaphragm and the other respiratory muscles. Dynamic techniques include fluoroscopy, M-mode (motion mode) ultrasound and MRI, used to assess diaphragm motion in one or more directions. We discuss how these imaging techniques relate with spirometric values and whether these can be used to study the contribution of the different respiratory muscles in patients with neuromuscular disease. Copyright © 2017. Published by Elsevier B.V.

Numerical solution methods for viscoelastic orthotropic materials

NASA Technical Reports Server (NTRS)

Gramoll, K. C.; Dillard, D. A.; Brinson, H. F.

1988-01-01

Numerical solution methods for viscoelastic orthotropic materials, specifically fiber reinforced composite materials, are examined. The methods include classical lamination theory using time increments, direction solution of the Volterra Integral, Zienkiewicz's linear Prony series method, and a new method called Nonlinear Differential Equation Method (NDEM) which uses a nonlinear Prony series. The criteria used for comparison of the various methods include the stability of the solution technique, time step size stability, computer solution time length, and computer memory storage. The Volterra Integral allowed the implementation of higher order solution techniques but had difficulties solving singular and weakly singular compliance function. The Zienkiewicz solution technique, which requires the viscoelastic response to be modeled by a Prony series, works well for linear viscoelastic isotropic materials and small time steps. The new method, NDEM, uses a modified Prony series which allows nonlinear stress effects to be included and can be used with orthotropic nonlinear viscoelastic materials. The NDEM technique is shown to be accurate and stable for both linear and nonlinear conditions with minimal computer time.

Advanced particle-in-cell simulation techniques for modeling the Lockheed Martin Compact Fusion Reactor

NASA Astrophysics Data System (ADS)

Welch, Dale; Font, Gabriel; Mitchell, Robert; Rose, David

2017-10-01

We report on particle-in-cell developments of the study of the Compact Fusion Reactor. Millisecond, two and three-dimensional simulations (cubic meter volume) of confinement and neutral beam heating of the magnetic confinement device requires accurate representation of the complex orbits, near perfect energy conservation, and significant computational power. In order to determine initial plasma fill and neutral beam heating, these simulations include ionization, elastic and charge exchange hydrogen reactions. To this end, we are pursuing fast electromagnetic kinetic modeling algorithms including a two implicit techniques and a hybrid quasi-neutral algorithm with kinetic ions. The kinetic modeling includes use of the Poisson-corrected direct implicit, magnetic implicit, as well as second-order cloud-in-cell techniques. The hybrid algorithm, ignoring electron inertial effects, is two orders of magnitude faster than kinetic but not as accurate with respect to confinement. The advantages and disadvantages of these techniques will be presented. Funded by Lockheed Martin.

Benefits of a holistic breathing technique in patients on hemodialysis.

PubMed

Stanley, Ruth; Leither, Thomas W; Sindelir, Cathy

2011-01-01

Health-related quality of life and heart rate variability are often depressed in patients on hemodialysis. This pilot program used a simple holistic, self-directed breathing technique designed to improve heart rate variability, with the hypothesis that improving heart rate variability would subsequently enhance health-related quality of life. Patient self-reported benefits included reductions in anxiety, fatigue, insomnia, and pain. Using holistic physiologic techniques may offer a unique and alternative tool for nurses to help increase health-related quality of life in patients on hemodialysis.

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.

New Directions in Special Education.

ERIC Educational Resources Information Center

Jones, Reginald L., Ed.

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

Proceedings of the First National Workshop on the Global Weather Experiment: Current Achievements and Future Directions, volume 2, part 1

NASA Technical Reports Server (NTRS)

1985-01-01

Topics covered include: data systems and quality; analysis and assimilation techniques; impacts on forecasts; tropical forecasts; analysis intercomparisons; improvements in predictability; and heat sources and sinks.

Suggested Sources for Teaching about the Bill of Rights.

ERIC Educational Resources Information Center

Pahl, Ronald H.

1991-01-01

Provides an annotated bibliography of materials for use in teaching about the Bill of Rights. Includes items selected for their breadth of instructional techniques, variety of sources, and uniqueness. States prices and directions for obtaining the materials. (SG)

The Battered Teacher

ERIC Educational Resources Information Center

Bloch, Alfred M.

1977-01-01

Methods for the prevention and control of stress and trauma in physically assaulted teachers include preparedness training, formation of crisis intervention teams, and morale-improving techniques such as staff support, rotation of teaching assignments, and direct access to schoolboards for grievance reports. (MJB)

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.

A simple technique for laparoscopic gastrostomy.

PubMed

Murphy, C; Rosemurgy, A S; Albrink, M H; Carey, L C

1992-05-01

While endoscopically placed gastrostomy tubes are routinely simple, they are not always feasible. Endoscopic technique also does not uniformly secure the tube to the abdominal wall, which presents possible complications, including leakage, accidental early tube removal, intraperitoneal catheter migration and necrosis of the stomach or abdominal wall because of excessive traction. Presented herein is a technique that is rapid, simple and eliminates some of these potential complications. The technique is easily combined with other operative procedures, such as tracheostomy, is done under direct vision, can be performed quickly with intravenous sedation and local anesthetic and is a safe method of tube placement for enteral feeding or gastric decompression.

Silicon microring resonators

NASA Astrophysics Data System (ADS)

Tan, Ying; Dai, Daoxin

2018-05-01

Silicon microring resonators (MRRs) are very popular for many applications because of the advantages of footprint compactness, easy scalability, and functional versatility. Ultra-compact silicon MRRs with box-like spectral responses are realized with a very large free-spectral range (FSR) by introducing bent directional couplers. The measured box-like spectral response has an FSR of >30 nm. The permanent wavelength-alignment techniques for MRRs are also presented, including the laser-induced local-oxidation technique as well as the local-etching technique. With these techniques, one can control finely the permanent wavelength shift, which is also large enough to compensate the random wavelength variation due to the random fabrication errors.

A new technique of deploying dynamic y stent using flexible bronchoscope, video laryngoscope, and laryngeal mask airway.

PubMed

Obeidat, Shadi; Badin, Shadi; Khawaja, Imran

2010-04-01

Dynamic Y stents are used in tracheobronchial obstruction, tracheal stenosis, and tracheomalacia. Placement may be difficult and is usually accomplished using a rigid grasping forceps (under fluoroscopic guidance) or a rigid bronchoscope. We report using a new stent placement technique on an elderly patient with a central tracheobronchial tumor. It included using a flexible bronchoscope, video laryngoscope, and laryngeal mask airway. The new technique we used has the advantages of continuous direct endoscopic visualization during stent advancement and manipulation, and securing the airways with a laryngeal mask airway at the same time. This technique eliminates the need for intraoperative fluoroscopy.

Indexing and retrieval of MPEG compressed video

NASA Astrophysics Data System (ADS)

Kobla, Vikrant; Doermann, David S.

1998-04-01

To keep pace with the increased popularity of digital video as an archival medium, the development of techniques for fast and efficient analysis of ideo streams is essential. In particular, solutions to the problems of storing, indexing, browsing, and retrieving video data from large multimedia databases are necessary to a low access to these collections. Given that video is often stored efficiently in a compressed format, the costly overhead of decompression can be reduced by analyzing the compressed representation directly. In earlier work, we presented compressed domain parsing techniques which identified shots, subshots, and scenes. In this article, we present efficient key frame selection, feature extraction, indexing, and retrieval techniques that are directly applicable to MPEG compressed video. We develop a frame type independent representation which normalizes spatial and temporal features including frame type, frame size, macroblock encoding, and motion compensation vectors. Features for indexing are derived directly from this representation and mapped to a low- dimensional space where they can be accessed using standard database techniques. Spatial information is used as primary index into the database and temporal information is used to rank retrieved clips and enhance the robustness of the system. The techniques presented enable efficient indexing, querying, and retrieval of compressed video as demonstrated by our system which typically takes a fraction of a second to retrieve similar video scenes from a database, with over 95 percent recall.

When lithography meets self-assembly: a review of recent advances in the directed assembly of complex metal nanostructures on planar and textured surfaces

NASA Astrophysics Data System (ADS)

Hughes, Robert A.; Menumerov, Eredzhep; Neretina, Svetlana

2017-07-01

One of the foremost challenges in nanofabrication is the establishment of a processing science that integrates wafer-based materials, techniques, and devices with the extraordinary physicochemical properties accessible when materials are reduced to nanoscale dimensions. Such a merger would allow for exacting controls on nanostructure positioning, promote cooperative phenomenon between adjacent nanostructures and/or substrate materials, and allow for electrical contact to individual or groups of nanostructures. With neither self-assembly nor top-down lithographic processes being able to adequately meet this challenge, advancements have often relied on a hybrid strategy that utilizes lithographically-defined features to direct the assembly of nanostructures into organized patterns. While these so-called directed assembly techniques have proven viable, much of this effort has focused on the assembly of periodic arrays of spherical or near-spherical nanostructures comprised of a single element. Work directed toward the fabrication of more complex nanostructures, while still at a nascent stage, has nevertheless demonstrated the possibility of forming arrays of nanocubes, nanorods, nanoprisms, nanoshells, nanocages, nanoframes, core-shell structures, Janus structures, and various alloys on the substrate surface. In this topical review, we describe the progress made in the directed assembly of periodic arrays of these complex metal nanostructures on planar and textured substrates. The review is divided into three broad strategies reliant on: (i) the deterministic positioning of colloidal structures, (ii) the reorganization of deposited metal films at elevated temperatures, and (iii) liquid-phase chemistry practiced directly on the substrate surface. These strategies collectively utilize a broad range of techniques including capillary assembly, microcontact printing, chemical surface modulation, templated dewetting, nanoimprint lithography, and dip-pen nanolithography and employ a wide scope of chemical processes including redox reactions, alloying, dealloying, phase separation, galvanic replacement, preferential etching, template-mediated reactions, and facet-selective capping agents. Taken together, they highlight the diverse toolset available when fabricating organized surfaces of substrate-supported nanostructures.

[Manual airway clearance techniques in adults and adolescents: What level of evidence?

PubMed

Cabillic, Michel; Gouilly, Pascal; Reychler, Gregory

2016-04-13

The aim of this systematic literature review was to grade the levels of evidence of the most widely used manual airway clearance techniques. A literature search was conducted over the period 1995-2014 from the Medline, PEDro, ScienceDirect, Cochrane Library, REEDOC and kinedoc databases, with the following keywords: "postural drainage", "manual vibrations", "manual chest percussion", "directed cough", "increased expiratory flow", "ELTGOL", "autogenic drainage" and "active cycle of breathing technique". Two-hundred and fifty-six articles were identified. After removing duplicates and reading the titles and abstracts, 63 articles were selected, including 9 systematic reviews. This work highlights the lack of useful scientific data and the difficulty of determining levels of evidence for manual airway clearance techniques. Techniques were assessed principally with patients with sputum production (cystic fibrosis, DDB, COPD, etc.). It also shows the limited pertinence of outcome measures to quantify congestion and hence the efficacy of airway clearance techniques. The 1994 consensus conference summary table classifying airway clearance techniques according to physical mechanism provides an interesting tool for assessment, grouping together techniques having identical mechanisms of action. From the findings of the present systematic review, it appears that only ELTGOL, autogenic drainage and ACBT present levels of evidence "B". All other techniques have lower levels of evidence. II. Copyright © 2016. Published by Elsevier Masson SAS.

Intact unconscious processing of eye contact in schizophrenia.

PubMed

Seymour, Kiley; Rhodes, Gillian; Stein, Timo; Langdon, Robyn

2016-03-01

The perception of eye gaze is crucial for social interaction, providing essential information about another person's goals, intentions, and focus of attention. People with schizophrenia suffer a wide range of social cognitive deficits, including abnormalities in eye gaze perception. For instance, patients have shown an increased bias to misjudge averted gaze as being directed toward them. In this study we probed early unconscious mechanisms of gaze processing in schizophrenia using a technique known as continuous flash suppression. Previous research using this technique to render faces with direct and averted gaze initially invisible reveals that direct eye contact gains privileged access to conscious awareness in healthy adults. We found that patients, as with healthy control subjects, showed the same effect: faces with direct eye gaze became visible significantly faster than faces with averted gaze. This suggests that early unconscious processing of eye gaze is intact in schizophrenia and implies that any misjudgments of gaze direction must manifest at a later conscious stage of gaze processing where deficits and/or biases in attributing mental states to gaze and/or beliefs about being watched may play a role.

Directed evolution: tailoring biocatalysts for industrial applications.

PubMed

Kumar, Ashwani; Singh, Suren

2013-12-01

Current challenges and promises of white biotechnology encourage protein engineers to use a directed evolution approach to generate novel and useful biocatalysts for various sets of applications. Different methods of enzyme engineering have been used in the past in an attempt to produce enzymes with improved functions and properties. Recent advancement in the field of random mutagenesis, screening, selection and computational design increased the versatility and the rapid development of enzymes under strong selection pressure with directed evolution experiments. Techniques of directed evolution improve enzymes fitness without understanding them in great detail and clearly demonstrate its future role in adapting enzymes for use in industry. Despite significant advances to date regarding biocatalyst improvement, there still remains a need to improve mutagenesis strategies and development of easy screening and selection tools without significant human intervention. This review covers fundamental and major development of directed evolution techniques, and highlights the advances in mutagenesis, screening and selection methods with examples of enzymes developed by using these approaches. Several commonly used methods for creating molecular diversity with their advantages and disadvantages including some recently used strategies are also discussed.

Microscale patterning of thermoplastic polymer surfaces by selective solvent swelling.

PubMed

Rahmanian, Omid; Chen, Chien-Fu; DeVoe, Don L

2012-09-04

A new method for the fabrication of microscale features in thermoplastic substrates is presented. Unlike traditional thermoplastic microfabrication techniques, in which bulk polymer is displaced from the substrate by machining or embossing, a unique process termed orogenic microfabrication has been developed in which selected regions of a thermoplastic surface are raised from the substrate by an irreversible solvent swelling mechanism. The orogenic technique allows thermoplastic surfaces to be patterned using a variety of masking methods, resulting in three-dimensional features that would be difficult to achieve through traditional microfabrication methods. Using cyclic olefin copolymer as a model thermoplastic material, several variations of this process are described to realize growth heights ranging from several nanometers to tens of micrometers, with patterning techniques include direct photoresist masking, patterned UV/ozone surface passivation, elastomeric stamping, and noncontact spotting. Orogenic microfabrication is also demonstrated by direct inkjet printing as a facile photolithography-free masking method for rapid desktop thermoplastic microfabrication.

Research perspectives in first metatarsal osteotomy and fixation stability.

PubMed

Landsman, A S; Higgins, K R; Lampe, N

1996-07-01

Well-designated research is required to provide clinical guidance by validation of old and new methods. Variables, including technologic advancement in surgical techniques, diagnosis, shoe design, and immobilization all contribute to the challenge of investigating surgical procedures of the foot. This article highlights some of the relevant research pertaining to first metatarsal osteotomies and internal fixation and provides direction for potential, future research. Numerous aspects about the research techniques involved are discussed.

The integrated manual and automatic control of complex flight systems

NASA Technical Reports Server (NTRS)

Schmidt, D. K.

1986-01-01

The topics of research in this program include pilot/vehicle analysis techniques, identification of pilot dynamics, and control and display synthesis techniques for optimizing aircraft handling qualities. The project activities are discussed. The current technical activity is directed at extending and validating the active display synthesis procedure, and the pilot/vehicle analysis of the NLR rate-command flight configurations in the landing task. Two papers published by the researchers are attached as appendices.

Advances in facial reanimation.

PubMed

Tate, James R; Tollefson, Travis T

2006-08-01

Facial paralysis often has a significant emotional impact on patients. Along with the myriad of new surgical techniques in managing facial paralysis comes the challenge of selecting the most effective procedure for the patient. This review delineates common surgical techniques and reviews state-of-the-art techniques. The options for dynamic reanimation of the paralyzed face must be examined in the context of several patient factors, including age, overall health, and patient desires. The best functional results are obtained with direct facial nerve anastomosis and interpositional nerve grafts. In long-standing facial paralysis, temporalis muscle transfer gives a dependable and quick result. Microvascular free tissue transfer is a reliable technique with reanimation potential whose results continue to improve as microsurgical expertise increases. Postoperative results can be improved with ancillary soft tissue procedures, as well as botulinum toxin. The paper provides an overview of recent advances in facial reanimation, including preoperative assessment, surgical reconstruction options, and postoperative management.

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.

Screening for trace explosives by AccuTOF™-DART®: an in-depth validation study.

PubMed

Sisco, Edward; Dake, Jeffrey; Bridge, Candice

2013-10-10

Ambient ionization mass spectrometry is finding increasing utility as a rapid analysis technique in a number of fields. In forensic science specifically, analysis of many types of samples, including drugs, explosives, inks, bank dye, and lotions, has been shown to be possible using these techniques [1]. This paper focuses on one type of ambient ionization mass spectrometry, Direct Analysis in Real Time Mass Spectrometry (DART-MS or DART), and its viability as a screening tool for trace explosives analysis. In order to assess viability, a validation study was completed which focused on the analysis of trace amounts of nitro and peroxide based explosives. Topics which were studied, and are discussed, include method optimization, reproducibility, sensitivity, development of a search library, discrimination of mixtures, and blind sampling. Advantages and disadvantages of this technique over other similar screening techniques are also discussed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

What Is Instrumented Learning? Part 1

ERIC Educational Resources Information Center

Blake, Robert; Mouton, Jane

1972-01-01

Although article is directed specifically towards improving sales techniques through self evaluation, it discusses various autoinstructional aids that could be applied to other fields. These include self-ranking against an objectives" grid, forced and multiple choice quizzes and the sentence-completion approach. (PD)

Mathematics and Information Retrieval.

ERIC Educational Resources Information Center

Salton, Gerald

1979-01-01

Examines the main mathematical approaches to information retrieval, including both algebraic and probabilistic models, and describes difficulties which impede formalization of information retrieval processes. A number of developments are covered where new theoretical understandings have directly led to improved retrieval techniques and operations.…

Trace analysis of energetic materials via direct analyte-probed nanoextraction coupled to direct analysis in real time mass spectrometry.

PubMed

Clemons, Kristina; Dake, Jeffrey; Sisco, Edward; Verbeck, Guido F

2013-09-10

Direct analysis in real time mass spectrometry (DART-MS) has proven to be a useful forensic tool for the trace analysis of energetic materials. While other techniques for detecting trace amounts of explosives involve extraction, derivatization, solvent exchange, or sample clean-up, DART-MS requires none of these. Typical DART-MS analyses directly from a solid sample or from a swab have been quite successful; however, these methods may not always be an optimal sampling technique in a forensic setting. For example, if the sample were only located in an area which included a latent fingerprint of interest, direct DART-MS analysis or the use of a swab would almost certainly destroy the print. To avoid ruining such potentially invaluable evidence, another method has been developed which will leave the fingerprint virtually untouched. Direct analyte-probed nanoextraction coupled to nanospray ionization-mass spectrometry (DAPNe-NSI-MS) has demonstrated excellent sensitivity and repeatability in forensic analyses of trace amounts of illicit drugs from various types of surfaces. This technique employs a nanomanipulator in conjunction with bright-field microscopy to extract single particles from a surface of interest and has provided a limit of detection of 300 attograms for caffeine. Combining DAPNe with DART-MS provides another level of flexibility in forensic analysis, and has proven to be a sufficient detection method for trinitrotoluene (TNT), RDX, and 1-methylaminoanthraquinone (MAAQ). Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Efficient techniques for wave-based sound propagation in interactive applications

NASA Astrophysics Data System (ADS)

Mehra, Ravish

Sound propagation techniques model the effect of the environment on sound waves and predict their behavior from point of emission at the source to the final point of arrival at the listener. Sound is a pressure wave produced by mechanical vibration of a surface that propagates through a medium such as air or water, and the problem of sound propagation can be formulated mathematically as a second-order partial differential equation called the wave equation. Accurate techniques based on solving the wave equation, also called the wave-based techniques, are too expensive computationally and memory-wise. Therefore, these techniques face many challenges in terms of their applicability in interactive applications including sound propagation in large environments, time-varying source and listener directivity, and high simulation cost for mid-frequencies. In this dissertation, we propose a set of efficient wave-based sound propagation techniques that solve these three challenges and enable the use of wave-based sound propagation in interactive applications. Firstly, we propose a novel equivalent source technique for interactive wave-based sound propagation in large scenes spanning hundreds of meters. It is based on the equivalent source theory used for solving radiation and scattering problems in acoustics and electromagnetics. Instead of using a volumetric or surface-based approach, this technique takes an object-centric approach to sound propagation. The proposed equivalent source technique generates realistic acoustic effects and takes orders of magnitude less runtime memory compared to prior wave-based techniques. Secondly, we present an efficient framework for handling time-varying source and listener directivity for interactive wave-based sound propagation. The source directivity is represented as a linear combination of elementary spherical harmonic sources. This spherical harmonic-based representation of source directivity can support analytical, data-driven, rotating or time-varying directivity function at runtime. Unlike previous approaches, the listener directivity approach can be used to compute spatial audio (3D audio) for a moving, rotating listener at interactive rates. Lastly, we propose an efficient GPU-based time-domain solver for the wave equation that enables wave simulation up to the mid-frequency range in tens of minutes on a desktop computer. It is demonstrated that by carefully mapping all the components of the wave simulator to match the parallel processing capabilities of the graphics processors, significant improvement in performance can be achieved compared to the CPU-based simulators, while maintaining numerical accuracy. We validate these techniques with offline numerical simulations and measured data recorded in an outdoor scene. We present results of preliminary user evaluations conducted to study the impact of these techniques on user's immersion in virtual environment. We have integrated these techniques with the Half-Life 2 game engine, Oculus Rift head-mounted display, and Xbox game controller to enable users to experience high-quality acoustics effects and spatial audio in the virtual environment.

Electron molecular ion recombination: product excitation and fragmentation.

PubMed

Adams, Nigel G; Poterya, Viktoriya; Babcock, Lucia M

2006-01-01

Electron-ion dissociative recombination is an important ionization loss process in any ionized gas containing molecular ions. This includes the interstellar medium, circumstellar shells, cometary comae, planetary ionospheres, fusion plasma boundaries, combustion flames, laser plasmas and chemical deposition and etching plasmas. In addition to controlling the ionization density, the process generates many radical species, which can contribute to a parallel neutral chemistry. Techniques used to obtain rate data and product information (flowing afterglows and storage rings) are discussed and recent data are reviewed including diatomic to polyatomic ions and cluster ions. The data are divided into rate coefficients and cross sections, including their temperature/energy dependencies, and quantitative identification of neutral reaction products. The latter involve both ground and electronically excited states and including vibrational excitation. The data from the different techniques are compared and trends in the data are examined. The reactions are considered in terms of the basic mechanisms (direct and indirect processes including tunneling) and recent theoretical developments are discussed. Finally, new techniques are mentioned (for product identification; electrostatic storage rings, including single and double rings; Coulomb explosion) and new ways forward are suggested.

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.

Research in Biological and Medical Sciences Including Biochemistry, Communicable Disease and Immunology, Internal Medicine, Physiology, Psychiatry, Surgery, and Veterinary Medicine. Volume 2

DTIC Science & Technology

1979-09-01

black-plate method were found infected with R. tsutsugamushi using the direct fluorescent antibody technique ( FAT )(4). Antigenic analyses of these...density of vector chiggers (Figures 3 and 4). Of the 96 rodent isolates, 67 (69.8%) were characterized by the direct FAT (Table 3). The majority of the...8), and the identification of R. tsutsugamushi organisms in unengorged chiggers was made by direct FAT (4)(Table 7). Results showed that 103 of 155

The Coronal Tooth Fractures: Preliminary Evaluation of a Three-Year Follow-Up of the Anterior Teeth Direct Fragment Reattachment Technique Without Additional Preparation.

PubMed

Giudice G, Lo; A, Alibrandi; F, Lipari; A, Lizio; F, Lauritano; G, Cervino; M, Cicciù

2017-01-01

The aim of this research is to describe and to analyse the long-term results and the clinical steps of direct fragment reattachment technique with no additional tooth preparation, used to treat crown fracture. This technique achieves the clinical success, combining satisfactory aesthetic and functional results with a minimally invasive approach. The 3 years follow-up included 9 patients (5 males, 4 females) with coronal fracture. In all the cases the fragment was available and intact. The authors illustrate the adhesive procedure used. Under local anaesthesia and after positioning the rubber dam, both the tooth and the fragment surface were etched, rinsed and applied by the adhesive system in order to obtain the retention of the fractured part to the tooth without additional tooth preparation or resin cement. The statistical analysis shows the good performances of direct fragment reattachment technique. After 36 months, in 22.2% of the cases, the detachment was observed of the bonded fragment and in 11.1% of patients, complications were recorded. Our clinical experience shows how the ultra-conservative procedure used is fast, easy and offers a long term predictability; it also allows good functional and aesthetic outcomes.

Position and Speed Control of Brushless DC Motors Using Sensorless Techniques and Application Trends

PubMed Central

Gamazo-Real, José Carlos; Vázquez-Sánchez, Ernesto; Gómez-Gil, Jaime

2010-01-01

This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC) motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order) and Artificial Neural Networks. PMID:22163582

Port closure techniques.

PubMed

Shaher, Z

2007-08-01

Laparoscopic trocars do create wounds. This article aims to review and list different techniques used for closure of the fascia incision at trocar sites. A literature search was performed for articles dealing with closure techniques. The author searched this subject in English on Medline by combining the words "trocar" and "hernia," as well as "Deschamps" and "Reverdin." All articles reporting techniques with their references were reviewed. The articles described many techniques in addition to classical closure using curved needles, including Grice needle, Maciol needles, Endoclose device, Carter-Thomason device, Tahoe ligature device, Endo-Judge device, eXit puncture closure device, Lowsley retractor, spinal cord needles, dual hemostat, suture carrier, Riverdin and Deschamps needles, and Gore-Tex closure device. Three main groups of techniques were found with favor of extracorporeal manipulations under direct visualization. Old methods are sufficient and cost-effective.

A Regional Analysis of U.S. Insurance Reimbursement Guidelines for Massage Therapy.

PubMed

Miccio, Robin S; Cowen, Virginia S

2018-03-01

Massage techniques fall within the scope of many different health care providers. Physical therapists, occupational therapists, and chiropractors receive insurance reimbursement for health care services, including massage. Although many patients pay out of pocket for massage services, it is unclear how the insurance company reimbursement policies factor provider qualifications into coverage. This project examined regional insurance reimbursement guidelines for massage therapy in relation to the role of the provider of massage services. A qualitative content analysis was used to explore guidelines for 26 health insurance policies across seven US companies providing coverage in the northeastern United States. Publicly available information relevant to massage was obtained from insurance company websites and extracted into a dataset for thematic analysis. Data obtained included practice guidelines, techniques, and provider requirements. Information from the dataset was coded and analyzed using descriptive statistics. Of the policies reviewed, 23% explicitly stated massage treatments were limited to 15-minute increments, 19% covered massage as one part of a comprehensive rehabilitation plan, and 27% required physician prescription. Massage techniques mentioned as qualifying for reimbursement included: Swedish, manual lymphatic drainage, mobilization/manipulation, myofascial release, and traction. Chiropractors, physical therapists, and occupational therapists could directly bill for massage. Massage therapists were specifically excluded as covered providers for seven (27%) policies. Although research supports massage for the treatment of a variety of conditions, the provider type has not been separately addressed. The reviewed policies that served the Northeastern states explicitly stated massage therapists could not bill insurance companies directly. The same insurance companies examined reimbursement for massage therapists in their western U.S. state policies. Other health care providers were able to bill directly for massage services to companies that did not accept direct billing by massage therapists. The specific exclusion of massage therapists as eligible providers violates the Affordable Care Act's non-discriminatory provision. Massage therapists should continue to advocate for reimbursement privileges to spur wider acceptance of massage therapy in health care.

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.

Recruitment of Physicians for the Active Army, 1975-1980

DTIC Science & Technology

1975-06-06

its supporting assets includinF the personnel counselor system and contract advertising capabilities: and, (4) comparison of physician pro curement...any criti- cism directed toward recruitment efforts has inhibited the use of available assets to include common corvmercial advertising techniques. 1 4...current Army procurement system and its supporting assets including the personnel counselor system ana contract advertising capabil- ities; and, (4

Magnetic Resonance Elastography and Other Magnetic Resonance Imaging Techniques in Chronic Liver Disease: Current Status and Future Directions.

PubMed

Tan, Cher Heng; Venkatesh, Sudhakar Kundapur

2016-09-15

Recent advances in the noninvasive imaging of chronic liver disease have led to improvements in diagnosis, particularly with magnetic resonance imaging (MRI). A comprehensive evaluation of the liver may be performed with the quantification of the degree of hepatic steatosis, liver iron concentration, and liver fibrosis. In addition, MRI of the liver may be used to identify complications of cirrhosis, including portal hypertension, ascites, and the development of hepatocellular carcinoma. In this review article, we discuss the state of the art techniques in liver MRI, namely, magnetic resonance elastography, hepatobiliary phase MRI, and liver fat and iron quantification MRI. The use of these advanced techniques in the management of chronic liver diseases, including nonalcoholic fatty liver disease, will be elaborated.

Magnetic Resonance Elastography and Other Magnetic Resonance Imaging Techniques in Chronic Liver Disease: Current Status and Future Directions

PubMed Central

Tan, Cher Heng; Venkatesh, Sudhakar Kundapur

2016-01-01

Recent advances in the noninvasive imaging of chronic liver disease have led to improvements in diagnosis, particularly with magnetic resonance imaging (MRI). A comprehensive evaluation of the liver may be performed with the quantification of the degree of hepatic steatosis, liver iron concentration, and liver fibrosis. In addition, MRI of the liver may be used to identify complications of cirrhosis, including portal hypertension, ascites, and the development of hepatocellular carcinoma. In this review article, we discuss the state of the art techniques in liver MRI, namely, magnetic resonance elastography, hepatobiliary phase MRI, and liver fat and iron quantification MRI. The use of these advanced techniques in the management of chronic liver diseases, including non-alcoholic fatty liver disease, will be elaborated. PMID:27563019

Comparison of carpal tunnel injection techniques: a cadaver study.

PubMed

Ozturk, Kahraman; Esenyel, Cem Zeki; Sonmez, Mesut; Esenyel, Meltem; Kahraman, Sinan; Senel, Berna

2008-01-01

The purpose of the study was to evaluate the accuracy of injections into the carpal tunnel using three different portals in cadavers, and to define safe guidelines. In this study, 150 wrists of 75 cadavers (54 male, 21 female) were included. To compare three injection sites, 50 wrists of 25 cadavers were used for each technique; we used 23 gauge needles, and acrylic dye. The first injection technique: the needle was inserted 1cm proximal to the wrist crease and directed distally by roughly 45 in an ulnar direction through the flexor carpi radialis tendon. The second injection technique: the needle was inserted into the carpal tunnel from a point just ulnar to the palmaris longus tendon and 1cm proximal to the wrist crease. The third injection technique: the needle was inserted just distal to the distal skin crease of the wrist in line with the fourth ray. The first injection technique gave the highest accuracy rate, and this was also the safest injection site. Median nerve injuries caused by injection was seen mostly with the second technique. Although a steroid injection may provide symptomatic relief in patients with carpal tunnel syndrome, the median nerve and other structures in the carpal tunnel are at risk of injury. Because of that, the injection should be given using the correct technique by physicians skilled in carpal tunnel surgery.

Exploring a Nearby Habitable World...Orbiting an M-Dwarf Star

NASA Technical Reports Server (NTRS)

Deming, Drake

2010-01-01

Topics include: the landscape of extrasolar planets and detection techniques, direct and indirect detection methods, summary of the known exoplanets, exploiting transits to characterize super earth atmospheres, how to characterize exoplanet atmospheres, and emitted or reflected spectra of hot Jupiters.

Tunnel-Site Selection by Remote Sensing Techniques

DTIC Science & Technology

A study of the role of remote sensing for geologic reconnaissance for tunnel-site selection was commenced. For this study, remote sensing was defined...conventional remote sensing . Future research directions are suggested, and the extension of remote sensing to include airborne passive microwave

The Stonehenge technique. A method for aligning coherent bremsstrahlung radiators

NASA Astrophysics Data System (ADS)

Livingston, Ken

2009-05-01

This paper describes a technique for the alignment of crystal radiators used to produce high energy, linearly polarized photons via coherent bremsstrahlung scattering at electron beam facilities. In these experiments the crystal is mounted on a goniometer which is used to adjust its orientation relative to the electron beam. The angles and equations which relate the crystal lattice, goniometer and electron beam direction are presented here, and the method of alignment is illustrated with data taken at MAMI (the Mainz microtron). A practical guide to setting up a coherent bremsstrahlung facility and installing new crystals using this technique is also included.

Calligraphic Poling of Ferroelectric Material

NASA Technical Reports Server (NTRS)

Mohageg, Makan; Strekalov, Dmitry; Savchenkov, Anatoliy; Matsko, Adrey; Maleki, Lute; Iltchenko, Vladimir

2007-01-01

Calligraphic poling is a technique for generating an arbitrary, possibly complex pattern of localized reversal in the direction of permanent polarization in a wafer of LiNbO3 or other ferroelectric material. The technique is so named because it involves a writing process in which a sharp electrode tip is moved across a surface of the wafer to expose the wafer to a polarizing electric field in the desired pattern. The technique is implemented by use of an apparatus, denoted a calligraphic poling machine (CPM), that includes the electrode and other components as described in more detail below.

Direct in situ observation of ZnO nucleation and growth via transmission X-ray microscopy

NASA Astrophysics Data System (ADS)

Tay, S. E. R.; Goode, A. E.; Nelson Weker, J.; Cruickshank, A. A.; Heutz, S.; Porter, A. E.; Ryan, M. P.; Toney, M. F.

2016-01-01

The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation.The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation. Electronic supplementary information (ESI) available: Methods and videos of nanoparticle growth. See DOI: 10.1039/c5nr07019h

Infrared fiber optic evanescent wave spectroscopy: applications in biology and medicine

NASA Astrophysics Data System (ADS)

Afanasyeva, Natalia I.; Bruch, Reinhard F.; Katzir, Abraham

1999-04-01

A new powerful and highly sensitive technique for non-invasive biomedical diagnostics in vivo has been developed using Infrared Fiberoptic Evanescent Wave Fourier Transform Spectroscopy (FEW-FTIR). This compact and portable method allows to detect functional chemical groups and bonds via vibrational spectroscopy directly from surfaces including living tissue. Such differences and similarities in molecular structure of tissue and materials can be evaluated online. Operating in the attenuated total reflection (ATR) regime in the middle-infrared (MIR) range, the FEW-FTIR technique provides direct contact between the fiber probe and tissue for non-destructive, non-invasive, fast and remote (few meters) diagnostics and quality control of materials. This method utilizes highly flexible and extremely low loss unclad fibers, for example silver halide fibers. Applications of this method include investigations of normal skin, precancerous and cancerous conditions, monitoring of the process of aging, allergic reactions and radiation damage to the skin. This setup is suitable as well for the detection of the influence of environmental factors (sun, water, pollution, and weather) on skin surfaces. The FEW-FTIR technique is very promising also for fast histological examinations in vitro. In this review, we present recent investigations of skin, breast, lung, stomach, kidney tissues in vivo and ex vivo (during surgery) to define the areas of tumor localization. The main advantages of the FEW-FTIR technique for biomedical, clinical, and environmental applications are discussed.

Secondary tracheoesophageal puncture in-office using Seldinger technique.

PubMed

Britt, Christopher J; Lippert, Dylan; Kammer, Rachael; Ford, Charles N; Dailey, Seth H; McCulloch, Timothy; Hartig, Gregory

2014-05-01

Evaluate the safety and efficacy of in-office secondary tracheoesophageal puncture (TEP) technique using transnasal esophagoscopy (TNE) and the Seldinger technique in conjunction with a cricothyroidotomy kit for placement. Case series with chart review. Academic medical center. A retrospective chart review was performed on 83 subjects who underwent in-office secondary TEP. Variables that were examined included disease site, staging, histologic diagnosis, extent of resection and reconstruction, chemoradiation, functional voice status (as assessed by speech pathologist in most recent note), and complications directly related to the procedure. Eighty-three individuals from our institution met our criteria for in-office secondary TEP from 2005 to August 2012. Of these, 97.6% (81/83) had no complications of TEP. The overall complication rate was 2.4% (2/83). Complications included bleeding from puncture site and closure of puncture site after dislodgement of prosthesis at the time of puncture. Fluent conversational speech was achieved in 69.9% of all patients (58/83), and an additional 19.3% (16/83) achieved functional/intelligible speech; of those, 3.6% (3/83) were unable to achieve fluent conversational speech due to anatomic defects from previous surgery. An in-office TEP can be safely performed using the Seldinger technique with direct visualization using TNE, despite the extent of resection or reconstruction, with functional speech outcomes comparable to other studies available in the literature.

Concepts for 20/30 GHz satcom systems for direct-to-user applications

NASA Technical Reports Server (NTRS)

Jorasch, R.; Davies, R.; Baker, M.

1980-01-01

A baseline technique is described for implementing a direct-to-user (DTU) satcom communications system at 20/30 GHz transmission frequency. The purpose of this application is to utilize the high capacity frequency spectrum at K(A) band for communications among thousands of small terminals located at or close to a customer's facility. The baseline DTU system utilizes a TDMA method of communications with QPSK modulation. Twenty-five coverage beams from a geosynchronous orbit spacecraft provide full coverage of CONUS. Low cost terminals are limited to less than 4.5 meters diameter. The impact of rain attenuation on communications availability is examined. Other techniques including satellite switched antenna beams are outlined and critical K(A)-band technology developments are identified.

Reverse Genetics of Newcastle Disease Virus.

PubMed

Cardenas-Garcia, Stivalis; Afonso, Claudio L

2017-01-01

Reverse genetics allows for the generation of recombinant viruses or vectors used in functional studies, vaccine development, and gene therapy. This technique enables genetic manipulation and cloning of viral genomes, gene mutation through site-directed mutagenesis, along with gene insertion or deletion, among other studies. An in vitro infection-based system including the highly attenuated vaccinia virus Ankara strain expressing the T7 RNA polymerase from bacteriophage T7, with co-transfection of three helper plasmids and a full-length cDNA plasmid, was successfully developed to rescue genetically modified Newcastle disease viruses in 1999. In this chapter, the materials and the methods involved in rescuing Newcastle disease virus (NDV) from cDNA, utilizing site-directed mutagenesis and gene replacement techniques, are described in detail.

[Blood culture negative endocarditis: a diagnostic challenge].

PubMed

Wälli, F; Chuard, C; Regamey, C

2005-10-12

Blood culture negative endocarditis (BCNE) account for about 5% of all cases of endocarditis. Diagnosis and initiation of antimicrobial therapy may be delayed, with a negative impact on clinical outcome. The most common cause of BCNE is antimicrobial drug therapy before blood sampling. Other common causes include slow growing and non cultivable organisms. Identification of the etiologic agent is critical in the management of BCNE and molecular tools such as broad range 16SrRNA PCR technique followed by direct automated sequencing and microorganism-specific PCR are promising. Some authors have proposed to include these techniques among major Duke's criteria for the diagnosis of BCNE.

Micromechanical Characterization and Texture Analysis of Direct Cast Titanium Alloys Strips

NASA Technical Reports Server (NTRS)

2000-01-01

This research was conducted to determine a post-processing technique to optimize mechanical and material properties of a number of Titanium based alloys and aluminides processed via Melt Overflow Solidification Technique (MORST). This technique was developed by NASA for the development of thin sheet titanium and titanium aluminides used in high temperature applications. The materials investigated in this study included conventional titanium alloy strips and foils, Ti-1100, Ti-24Al-11Nb (Alpha-2), and Ti-48Al-2Ta (Gamma). The methodology used included micro-characterization, heat-treatment, mechanical processing and mechanical testing. Characterization techniques included optical, electron microscopy, and x-ray texture analysis. The processing included heat-treatment and mechanical deformation through cold rolling. The initial as-cast materials were evaluated for their microstructure and mechanical properties. Different heat-treatment and rolling steps were chosen to process these materials. The properties were evaluated further and a processing relationship was established in order to obtain an optimum processing condition. The results showed that the as-cast material exhibited a Widmanstatten (fine grain) microstructure that developed into a microstructure with larger grains through processing steps. The texture intensity showed little change for all processing performed in this investigation.

The safety of 17a-methyltestosterone administered in feed to larval Nile tilapia

USDA-ARS?s Scientific Manuscript database

Techniques developed to control sexual differentiation in fishes have typically involved androgen or estrogen (i.e., steroid) treatment, which directs sexual differentiation toward males or females. Treatment regimens have included immersion of larval fish in water containing a steroid, incorporati...

From Information Center to Discovery System: Next Step for Libraries?

ERIC Educational Resources Information Center

Marcum, James W.

2001-01-01

Proposes a discovery system model to guide technology integration in academic libraries that fuses organizational learning, systems learning, and knowledge creation techniques with constructivist learning practices to suggest possible future directions for digital libraries. Topics include accessing visual and continuous media; information…

Managing Nonpoint Source Pollution in Western Washington: Landowner Learning Methods and Motivations

NASA Astrophysics Data System (ADS)

Ryan, Clare M.

2009-06-01

States, territories, and tribes identify nonpoint source pollution as responsible for more than half of the Nation’s existing and threatened water quality impairments, making it the principal remaining cause of water quality problems across the United States. Combinations of education, technical and financial assistance, and regulatory measures are used to inform landowners about nonpoint source pollution issues, and to stimulate the use of best management practices. A mail survey of non-commercial riparian landowners investigated how they learn about best management practices, the efficacy of different educational techniques, and what motivates them to implement land management activities. Landowners experience a variety of educational techniques, and rank those that include direct personal contact as more effective than brochures, advertisements, radio, internet, or television. The most important motivations for implementing best management practices were linked with elements of a personal stewardship ethic, accountability, personal commitment, and feasibility. Nonpoint source education and social marketing campaigns should include direct interpersonal contacts, and appeal to landowner motivations of caring, responsibility, and personal commitment.

Data management issues in mobile ad hoc networks

PubMed Central

HARA, Takahiro

2017-01-01

Research on mobile ad hoc networks (MANETs) has become a hot research topic since the middle 1990’s. Over the first decade, most research focused on networking techniques, ignoring data management issues. We, however, realized early the importance of data management in MANETs, and have been conducting studies in this area for 15 years. In this review, we summarize some key technical issues related to data management in MANETs, and the studies we have done in addressing these issues, which include placement of data replicas, update management, and query processing with security management. The techniques proposed in our studies have been designed with deep considerations of MANET features including network partitioning, node participation/disappearance, limited network bandwidth, and energy efficiency. Our studies published in early 2000’s have developed a new research field as data management in MANETs. Also, our recent studies are expected to be significant guidelines of new research directions. We conclude the review by discussing some future directions for research. PMID:28496052

Power measurement system of ECRH on HL-2A

NASA Astrophysics Data System (ADS)

Wang, He; Lu, Zhihong; Kubo, Shin; Chen, Gangyu; Wang, Chao; Zhou, Jun; Huang, Mei; Rao, Jun

2015-03-01

Electron Cyclotron Resonance Heating (ECRH) is one of the main auxiliary heating systems for HL-2A tokamak. The ECRH system with total output power 5MW has been equipped on HL-2A which include 6 sets of 0.5MW/1.0s at a frequency of 68GHz and 2 sets of 1MW/3s at a frequency of 140GHz. The power is one of important parameters in ECRH system. In this paper, the method for measuring the power of ECRH system on HL-2A is introduced which include calorimetric techniques and directional coupler. Calorimetric techniques is an existing method, which is used successfully in ECRH commissioning and experiment, and the transmission efficiency of ECRH system is achieved by measuring the absorbed microwave power in the Match Optical Unit (MOU), gyrotron output window and tours window of the EC system use this method. Now base on the theory of electromagnetic coupling through apertures, directional couplers are being designed, which is a new way for us.

Data management issues in mobile ad hoc networks.

PubMed

Hara, Takahiro

2017-01-01

Research on mobile ad hoc networks (MANETs) has become a hot research topic since the middle 1990's. Over the first decade, most research focused on networking techniques, ignoring data management issues. We, however, realized early the importance of data management in MANETs, and have been conducting studies in this area for 15 years. In this review, we summarize some key technical issues related to data management in MANETs, and the studies we have done in addressing these issues, which include placement of data replicas, update management, and query processing with security management. The techniques proposed in our studies have been designed with deep considerations of MANET features including network partitioning, node participation/disappearance, limited network bandwidth, and energy efficiency. Our studies published in early 2000's have developed a new research field as data management in MANETs. Also, our recent studies are expected to be significant guidelines of new research directions. We conclude the review by discussing some future directions for research.

Array magnetics modal analysis for the DIII-D tokamak based on localized time-series modelling

DOE PAGES

Olofsson, K. Erik J.; Hanson, Jeremy M.; Shiraki, Daisuke; ...

2014-07-14

Here, time-series analysis of magnetics data in tokamaks is typically done using block-based fast Fourier transform methods. This work presents the development and deployment of a new set of algorithms for magnetic probe array analysis. The method is based on an estimation technique known as stochastic subspace identification (SSI). Compared with the standard coherence approach or the direct singular value decomposition approach, the new technique exhibits several beneficial properties. For example, the SSI method does not require that frequencies are orthogonal with respect to the timeframe used in the analysis. Frequencies are obtained directly as parameters of localized time-series models.more » The parameters are extracted by solving small-scale eigenvalue problems. Applications include maximum-likelihood regularized eigenmode pattern estimation, detection of neoclassical tearing modes, including locked mode precursors, and automatic clustering of modes, and magnetics-pattern characterization of sawtooth pre- and postcursors, edge harmonic oscillations and fishbones.« less

Ambient Mass Spectrometry Imaging Using Direct Liquid Extraction Techniques

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

Laskin, Julia; Lanekoff, Ingela

2015-11-13

Mass spectrometry imaging (MSI) is a powerful analytical technique that enables label-free spatial localization and identification of molecules in complex samples.1-4 MSI applications range from forensics5 to clinical research6 and from understanding microbial communication7-8 to imaging biomolecules in tissues.1, 9-10 Recently, MSI protocols have been reviewed.11 Ambient ionization techniques enable direct analysis of complex samples under atmospheric pressure without special sample pretreatment.3, 12-16 In fact, in ambient ionization mass spectrometry, sample processing (e.g., extraction, dilution, preconcentration, or desorption) occurs during the analysis.17 This substantially speeds up analysis and eliminates any possible effects of sample preparation on the localization of moleculesmore » in the sample.3, 8, 12-14, 18-20 Venter and co-workers have classified ambient ionization techniques into three major categories based on the sample processing steps involved: 1) liquid extraction techniques, in which analyte molecules are removed from the sample and extracted into a solvent prior to ionization; 2) desorption techniques capable of generating free ions directly from substrates; and 3) desorption techniques that produce larger particles subsequently captured by an electrospray plume and ionized.17 This review focuses on localized analysis and ambient imaging of complex samples using a subset of ambient ionization methods broadly defined as “liquid extraction techniques” based on the classification introduced by Venter and co-workers.17 Specifically, we include techniques where analyte molecules are desorbed from solid or liquid samples using charged droplet bombardment, liquid extraction, physisorption, chemisorption, mechanical force, laser ablation, or laser capture microdissection. Analyte extraction is followed by soft ionization that generates ions corresponding to intact species. Some of the key advantages of liquid extraction techniques include the ease of operation, ability to analyze samples in their native environments, speed of analysis, and ability to tune the extraction solvent composition to a problem at hand. For example, solvent composition may be optimized for efficient extraction of different classes of analytes from the sample or for quantification or online derivatization through reactive analysis. In this review, we will: 1) introduce individual liquid extraction techniques capable of localized analysis and imaging, 2) describe approaches for quantitative MSI experiments free of matrix effects, 3) discuss advantages of reactive analysis for MSI experiments, and 4) highlight selected applications (published between 2012 and 2015) that focus on imaging and spatial profiling of molecules in complex biological and environmental samples.« less

Space Processing Application Rocket project, SPAR 5

NASA Technical Reports Server (NTRS)

Reeves, F. (Compiler); Schaefer, D. (Compiler)

1980-01-01

Post flight results and analysis are presented on the following experiments: 'Agglomeration in Immiscible Liquids', 'Contained Polycrystalline Solidification in Low G', 'The Direct Observation of Dendrite Remelting and Macrosegregation in Casting', and 'Uniform Dispersion by Crystallization'. An engineering report on the performance of the SPAR Black Brant rocket is also included. Much useful data and information were accumulated for directing and developing experimental techniques and investigations toward an expanding commercially beneficial program of materials processing in the coming shuttle era.

Directly Observing Micelle Fusion and Growth in Solution by Liquid-Cell Transmission Electron Microscopy

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

Parent, Lucas R.; Bakalis, Evangelos; Ramírez-Hernández, Abelardo

Amphiphilic small molecules and polymers form commonplace nanoscale macromolecular compartments and bilayers, and as such are truly essential components in all cells and in many cellular processes. The nature of these architectures, including their formation, phase changes, and stimuli-response behaviors, is necessary for the most basic functions of life, and over the past half-century, these natural micellar structures have inspired a vast diversity of industrial products, from biomedicines to detergents, lubricants, and coatings. The importance of these materials and their ubiquity have made them the subject of intense investigation regarding their nanoscale dynamics with increasing interest in obtaining sufficient temporalmore » and spatial resolution to directly observe nanoscale processes. However, the vast majority of experimental methods involve either bulk-averaging techniques including light, neutron, and X-ray scattering, or are static in nature including even the most advanced cryogenic transmission electron microscopy techniques. Here, we employ in situ liquid-cell transmission electron microscopy (LCTEM) to directly observe the evolution of individual amphiphilic block copolymer micellar nanoparticles in solution, in real time with nanometer spatial resolution. These observations, made on a proof-of-concept bioconjugate polymer amphiphile, revealed growth and evolution occurring by unimer addition processes and by particle-particle collision-and-fusion events. The experimental approach, combining direct LCTEM observation, quantitative analysis of LCTEM data, and correlated in silico simulations, provides a unique view of solvated soft matter nanoassemblies as they morph and evolve in time and space, enabling us to capture these phenomena in solution.« less

Measurement of Walking Ground Reactions in Real-Life Environments: A Systematic Review of Techniques and Technologies.

PubMed

Shahabpoor, Erfan; Pavic, Aleksandar

2017-09-12

Monitoring natural human gait in real-life environments is essential in many applications, including quantification of disease progression, monitoring the effects of treatment, and monitoring alteration of performance biomarkers in professional sports. Nevertheless, developing reliable and practical techniques and technologies necessary for continuous real-life monitoring of gait is still an open challenge. A systematic review of English-language articles from scientific databases including Scopus, ScienceDirect, Pubmed, IEEE Xplore, EBSCO and MEDLINE were carried out to analyse the 'accuracy' and 'practicality' of the current techniques and technologies for quantitative measurement of the tri-axial walking ground reactions outside the laboratory environment, and to highlight their strengths and shortcomings. In total, 679 relevant abstracts were identified, 54 full-text papers were included in the paper and the quantitative results of 17 papers were used for meta-analysis and comparison. Three classes of methods were reviewed: (1) methods based on measured kinematic data; (2) methods based on measured plantar pressure; and (3) methods based on direct measurement of ground reactions. It was found that all three classes of methods have competitive accuracy levels with methods based on direct measurement of the ground reactions showing highest accuracy while being least practical for long-term real-life measurement. On the other hand, methods that estimate ground reactions using measured body kinematics show highest practicality of the three classes of methods reviewed. Among the most prominent technical and technological challenges are: (1) reducing the size and price of tri-axial load-cells; (2) improving the accuracy of orientation measurement using IMUs; (3) minimizing the number and optimizing the location of required IMUs for kinematic measurement; (4) increasing the durability of pressure insole sensors, and (5) enhancing the robustness and versatility of the ground reactions estimation methods to include pathological gaits and natural variability of gait in real-life physical environment.

Measurement of Walking Ground Reactions in Real-Life Environments: A Systematic Review of Techniques and Technologies

PubMed Central

Shahabpoor, Erfan; Pavic, Aleksandar

2017-01-01

Monitoring natural human gait in real-life environments is essential in many applications, including quantification of disease progression, monitoring the effects of treatment, and monitoring alteration of performance biomarkers in professional sports. Nevertheless, developing reliable and practical techniques and technologies necessary for continuous real-life monitoring of gait is still an open challenge. A systematic review of English-language articles from scientific databases including Scopus, ScienceDirect, Pubmed, IEEE Xplore, EBSCO and MEDLINE were carried out to analyse the ‘accuracy’ and ‘practicality’ of the current techniques and technologies for quantitative measurement of the tri-axial walking ground reactions outside the laboratory environment, and to highlight their strengths and shortcomings. In total, 679 relevant abstracts were identified, 54 full-text papers were included in the paper and the quantitative results of 17 papers were used for meta-analysis and comparison. Three classes of methods were reviewed: (1) methods based on measured kinematic data; (2) methods based on measured plantar pressure; and (3) methods based on direct measurement of ground reactions. It was found that all three classes of methods have competitive accuracy levels with methods based on direct measurement of the ground reactions showing highest accuracy while being least practical for long-term real-life measurement. On the other hand, methods that estimate ground reactions using measured body kinematics show highest practicality of the three classes of methods reviewed. Among the most prominent technical and technological challenges are: (1) reducing the size and price of tri-axial load-cells; (2) improving the accuracy of orientation measurement using IMUs; (3) minimizing the number and optimizing the location of required IMUs for kinematic measurement; (4) increasing the durability of pressure insole sensors, and (5) enhancing the robustness and versatility of the ground reactions estimation methods to include pathological gaits and natural variability of gait in real-life physical environment. PMID:28895909

Comparison of the direct and indirect reduction techniques during the surgical management of posterior malleolar fractures.

PubMed

Shi, Hong-Fei; Xiong, Jin; Chen, Yi-Xin; Wang, Jun-Fei; Qiu, Xu-Sheng; Huang, Jie; Gui, Xue-Yang; Wen, Si-Yuan; Wang, Yin-He

2017-03-14

The optimal method for the reduction and fixation of posterior malleolar fracture (PMF) remains inconclusive. Currently, both of the indirect and direct reduction techniques are widely used. We aimed to compare the reduction quality and clinical outcome of posterior malleolar fracture managed with the direct reduction technique through posterolateral approach or the indirect reduction technique using ligamentotaxis. Patients with a PMF involving over 25% of the articular surface were recruited and assigned to the direct reduction (DR) group or the indirect reduction (IR) group. Following reduction and fixation of the fracture, the quality of fracture reduction was evaluated in post-operative CT images. Clinical and radiological follow-ups were performed at 6 weeks, 3 months, 6 months, 12 months, and then at 6 month-intervals postoperatively. Functional outcome (AOFAS score), ankle range of motion, and Visual Analog Scale (VAS) were evaluated at the last follow-up. Statistical differences were compared between the DR and IR groups considering the patient demographics, quality of fracture reduction, AOFAS score, and VAS. Totally 116 patients were included, wherein 64 cases were assigned to the DR group and 52 cases were assigned to the IR group. The quality of fracture reduction was significant higher in the DR group (P = 0.038). In the patients who completed a minimum of 12 months' follow-up, a median AOFAS score of 87 was recorded in the DR group, which was significantly higher than that recorded in the IR group (a median score of 80). The ankle range of motion was slightly better in the DR group, with the mean dorsiflexion restriction recorded to be 5.2° and 6.1° in the DR and IR group respectively (P = 0.331). Similar VAS score was observed in the two groups (P = 0.419). The direct reduction technique through a posterolateral approach provide better quality of fracture reduction and functional outcome in the management of PMF over 25% of articular surface, as compared with the indirect reduction technique using ligamentotaxis. NCT02801474 (retrospectively registered, June 2016, ClinicalTrails.gov).

Literature Review: Double-Barrelled Wet Colostomy (One Stoma) versus Ileal Conduit with Colostomy (Two Stomas).

PubMed

Gan, Jason; Hamid, Rizwan

2017-01-01

The aim of this literature review was to analyse the advantages and disadvantages of a traditional ileal conduit (IC) with separate colostomy technique compared to the outcomes of a double-barrelled wet colostomy (DBWC) technique. The former technique results in the formation of two stomas, and the latter results in the formation of one stoma. PubMed was searched electronically for articles on DBWC. Fifteen articles were retrieved and of them 13 were included in the literature review (350 patients). Of the articles, 3 directly compared DBWC to IC with colostomy. Review of 13 DBWC articles demonstrated perioperative mortality ranging between 0 and 11.1% and postoperative complications ranging from 0 to 100%. Three of the studies directly compared DBWC to IC with colostomy; median operating times and length of stay were shorter in DBWC patients (p < 0.001); 30-day morbidity was reported to either be lower in the DBWC group (p < 0.043) or to have no statistically significant difference. Rates of mortality, pyelonephritis, electrolyte disturbances and urinary anastomotic problems did not differ between the 2 groups. The DBWC technique inherently has a benefit over the IC with colostomy technique, as it requires only one stoma. This literature review supports the use of the technically less challenging DBWC technique as a viable alternative to the traditional IC with colostomy technique. © 2016 S. Karger AG, Basel.

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.

Review of Surgical Techniques of Experimental Renal Transplantation in Rats.

PubMed

Shrestha, Badri; Haylor, John

2017-08-01

Microvascular surgical techniques of renal transplant in rats have evolved over the past 5 decades to achieve successful rat renal transplant; these modifications have included surgical techniques to address the anatomic variations in the renal blood vessels and those to reduce ischemic and operation durations. Here, we review the surgical techniques of renal transplant in rats and evaluate the advantages and disadvantages of individual techniques of vascular and ureteric anastomoses. For this review, we performed a systematic literature search using relevant medical subject heading terms and included appropriate publications in the review. Since the first description of a rat model of renal transplant by Bernard Fisher and his colleagues in 1965, which used end-to-side anastomosis between the renal vein and renal artery to the recipient inferior vena cava and aorta, several vascular and ureteric anastomosis techniques have been modified. Vascular anastomosis techniques now include end-to-end anastomosis, use of donor aortic and inferior vena cava conduits, sleeve and cuff anastomoses, and application of fibrin glue. Likewise, restoration of the urinary tract can now be achieved by direct anastomosis of the donor ureter to the recipient bladder, end-to-end anastomosis between the donor and recipient ureters, and donor bladder cuff to the recipient bladder. There are advantages and disadvantages attributable to individual techniques. The range of vascular and ureteric anastomosis techniques that has emerged reflects the need for mastering more than one technique to suit the vascular anatomy of individual animals and to reduce operating time for achieving successful outcomes after renal transplant.

Signal and array processing techniques for RFID readers

NASA Astrophysics Data System (ADS)

Wang, Jing; Amin, Moeness; Zhang, Yimin

2006-05-01

Radio Frequency Identification (RFID) has recently attracted much attention in both the technical and business communities. It has found wide applications in, for example, toll collection, supply-chain management, access control, localization tracking, real-time monitoring, and object identification. Situations may arise where the movement directions of the tagged RFID items through a portal is of interest and must be determined. Doppler estimation may prove complicated or impractical to perform by RFID readers. Several alternative approaches, including the use of an array of sensors with arbitrary geometry, can be applied. In this paper, we consider direction-of-arrival (DOA) estimation techniques for application to near-field narrowband RFID problems. Particularly, we examine the use of a pair of RFID antennas to track moving RFID tagged items through a portal. With two antennas, the near-field DOA estimation problem can be simplified to a far-field problem, yielding a simple way for identifying the direction of the tag movement, where only one parameter, the angle, needs to be considered. In this case, tracking of the moving direction of the tag simply amounts to computing the spatial cross-correlation between the data samples received at the two antennas. It is pointed out that the radiation patterns of the reader and tag antennas, particularly their phase characteristics, have a significant effect on the performance of DOA estimation. Indoor experiments are conducted in the Radar Imaging and RFID Labs at Villanova University for validating the proposed technique for target movement direction estimations.

A comparative study of quantitative microsegregation analyses performed during the solidification of the Ni-base superalloy CMSX-10

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

Seo, Seong-Moon, E-mail: castme@kims.re.kr; Jeong, Hi-Won; Ahn, Young-Keun

Quantitative microsegregation analyses were systematically carried out during the solidification of the Ni-base superalloy CMSX-10 to clarify the methodological effect on the quantification of microsegregation and to fully understand the solidification microstructure. Three experimental techniques, namely, mushy zone quenching (MZQ), planar directional solidification followed by quenching (PDSQ), and random sampling (RS), were implemented for the analysis of microsegregation tendency and the magnitude of solute elements by electron probe microanalysis. The microprobe data and the calculation results of the diffusion field ahead of the solid/liquid (S/L) interface of PDSQ samples revealed that the liquid composition at the S/L interface is significantlymore » influenced by quenching. By applying the PDSQ technique, it was also found that the partition coefficients of all solute elements do not change appreciably during the solidification of primary γ. All three techniques could reasonably predict the segregation behavior of most solute elements. Nevertheless, the RS approach has a tendency to overestimate the magnitude of segregation for most solute elements when compared to the MZQ and PDSQ techniques. Moreover, the segregation direction of Cr and Mo predicted by the RS approach was found to be opposite from the results obtained by the MZQ and PDSQ techniques. This conflicting segregation behavior of Cr and Mo was discussed intensively. It was shown that the formation of Cr-rich areas near the γ/γ′ eutectic in various Ni-base superalloys, including the CMSX-10 alloy, could be successfully explained by the results of microprobe analysis performed on a sample quenched during the planar directional solidification of γ/γ′ eutectic. - Highlights: • Methodological effect on the quantification of microsegregation was clarified. • The liquid composition at the S/L interface was influenced by quenching. • The segregation direction of Cr varied depending on the experimental techniques. • Cr and Mo segregation in Ni-base superalloys was fully understood.« less

Something Old Is New Again: Revisiting Language Experience

ERIC Educational Resources Information Center

Dorr, Roberta E.

2006-01-01

Children arrive in classrooms with varied background knowledge, which means that teachers must select instructional methods, materials, and techniques to meet multiple needs. A carefully planned approach that includes direct and explicit instruction--as well as extensive opportunities for reading, writing, speaking, and listening--can help…

Field Hydraulic and Air-Blast Sprayers for Row Crops.

ERIC Educational Resources Information Center

Cole, Herbert, Jr., Comp.

This agriculture extension service publication from Pennsylvania State University discusses techniques and equipment used in spraying field crops. In the discussion of field hydraulic sprayers, specific topics include types of sprayers, tanks, pumps, pressure regulators, hoses, boom spraying, directed spraying, and nozzle bodies. In the discussion…

A simplified regional-scale electromagnetic induction - Salinity calibration model using ANOCOVA modeling techniques

USDA-ARS?s Scientific Manuscript database

Directed soil sampling based on geospatial measurements of apparent soil electrical conductivity (ECa) is a potential means of characterizing the spatial variability of any soil property that influences ECa including soil salinity, water content, texture, bulk density, organic matter, and cation exc...

Proceedings of the Eleventh Annual Precise Time and Time Interval (PTTI) Application and Planning Meeting. [conference

NASA Technical Reports Server (NTRS)

Wardrip, S. C. (Editor)

1979-01-01

Thirty eight papers are presented addressing various aspects of precise time and time interval applications. Areas discussed include: past accomplishments; state of the art systems; new and useful applications, procedures, and techniques; and fruitful directions for research efforts.

Education for the Information Age.

ERIC Educational Resources Information Center

Breivik, Patricia Senn

1992-01-01

To be effective in the current rapidly changing environment, individuals need more than a knowledge base. They also need information literacy which includes techniques for exploring new information, synthesizing it, and using it in practical ways. Undergraduate education should focus on such resource-based learning directed at problem solving.…

Detection of cortical optical changes during seizure activity using optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ornelas, Danielle; Hasan, Md.; Gonzalez, Oscar; Krishnan, Giri; Szu, Jenny I.; Myers, Timothy; Hirota, Koji; Bazhenov, Maxim; Binder, Devin K.; Park, Boris H.

2017-02-01

Electrophysiology has remained the gold standard of neural activity detection but its resolution and high susceptibility to noise and motion artifact limit its efficiency. Imaging techniques, including fMRI, intrinsic optical imaging, and diffuse optical imaging, have been used to detect neural activity, but rely on indirect measurements such as changes in blood flow. Fluorescence-based techniques, including genetically encoded indicators, are powerful techniques, but require introduction of an exogenous fluorophore. A more direct optical imaging technique is optical coherence tomography (OCT), a label-free, high resolution, and minimally invasive imaging technique that can produce depth-resolved cross-sectional and 3D images. In this study, we sought to examine non-vascular depth-dependent optical changes directly related to neural activity. We used an OCT system centered at 1310 nm to search for changes in an ex vivo brain slice preparation and an in vivo model during 4-AP induced seizure onset and propagation with respect to electrical recording. By utilizing Doppler OCT and the depth-dependency of the attenuation coefficient, we demonstrate the ability to locate and remove the optical effects of vasculature within the upper regions of the cortex from in vivo attenuation calculations. The results of this study show a non-vascular decrease in intensity and attenuation in ex vivo and in vivo seizure models, respectively. Regions exhibiting decreased optical changes show significant temporal correlation to regions of increased electrical activity during seizure. This study allows for a thorough and biologically relevant analysis of the optical signature of seizure activity both ex vivo and in vivo using OCT.

Direct Endonasal Approach with Partial Upper Posterior Septectomy. A “Rescue Flap” Technique Modification

PubMed Central

Sotomayor-González, Arturo; Díaz-Martínez, Armando José; Radillo-Gil, Ramón; García-Estrada, Everardo; Morales-Gómez, Jesús Alberto; Palacios-Ortiz, Isaac Jair; Pérez-Cárdenas, Samuel; Arteaga-Treviño, Mauricio; De León, Ángel Martínez-Ponce

2016-01-01

Objective Report a modification of the “rescue flap” technique using a direct endonasal approach with a partial superior septectomy for approaching pituitary tumors developed in our institution. Design Prospective study. Setting Hospital Universitario “Dr. José Eleuterio González,” Universidad Autónoma de Nuevo León. Main Outcome Measures Since April 2015, we have performed 19 cases employing a direct endonasal approach with partial superior septectomy. Results and a technical note are described below. Results Nineteen patients were included in this report. Six patients presented transoperatory cerebrospinal fluid (CSF) leak, so a nasoseptal rescue flap was harvested. No patients developed postoperative CSF leak in this group. Two patients were submitted to a second surgical procedure. Nasoseptal flap was harvested without complications. In both patients, the size of the flap was enough to cover the dural defect and avoid CSF leak. Conclusion Direct endonasal approach with a partial posterior septectomy allows enough exposition of the sphenoidal sinus while preserving the nasoseptal septum with the possibility of a successful rescue flap when needed. PMID:28321383

Direct Endonasal Approach with Partial Upper Posterior Septectomy. A "Rescue Flap" Technique Modification.

PubMed

Sotomayor-González, Arturo; Díaz-Martínez, Armando José; Radillo-Gil, Ramón; García-Estrada, Everardo; Morales-Gómez, Jesús Alberto; Palacios-Ortiz, Isaac Jair; Pérez-Cárdenas, Samuel; Arteaga-Treviño, Mauricio; De León, Ángel Martínez-Ponce

2017-04-01

Objective  Report a modification of the "rescue flap" technique using a direct endonasal approach with a partial superior septectomy for approaching pituitary tumors developed in our institution. Design  Prospective study. Setting  Hospital Universitario "Dr. José Eleuterio González," Universidad Autónoma de Nuevo León. Main Outcome Measures  Since April 2015, we have performed 19 cases employing a direct endonasal approach with partial superior septectomy. Results and a technical note are described below. Results  Nineteen patients were included in this report. Six patients presented transoperatory cerebrospinal fluid (CSF) leak, so a nasoseptal rescue flap was harvested. No patients developed postoperative CSF leak in this group. Two patients were submitted to a second surgical procedure. Nasoseptal flap was harvested without complications. In both patients, the size of the flap was enough to cover the dural defect and avoid CSF leak. Conclusion  Direct endonasal approach with a partial posterior septectomy allows enough exposition of the sphenoidal sinus while preserving the nasoseptal septum with the possibility of a successful rescue flap when needed.

High-Rate Assembly of Nanomaterials on Insulating Surfaces Using Electro-Fluidic Directed Assembly.

PubMed

Yilmaz, Cihan; Sirman, Asli; Halder, Aditi; Busnaina, Ahmed

2017-08-22

Conductive or semiconducting nanomaterials-based applications such as electronics and sensors often require direct placement of such nanomaterials on insulating surfaces. Most fluidic-based directed assembly techniques on insulating surfaces utilize capillary force and evaporation but are diffusion limited and slow. Electrophoretic-based assembly, on the other hand, is fast but can only be utilized for assembly on a conductive surface. Here, we present a directed assembly technique that enables rapid assembly of nanomaterials on insulating surfaces. The approach leverages and combines fluidic and electrophoretic assembly by applying the electric field through an insulating surface via a conductive film underneath. The approach (called electro-fluidic) yields an assembly process that is 2 orders of magnitude faster compared to fluidic assembly. By understanding the forces on the assembly process, we have demonstrated the controlled assembly of various types of nanomaterials that are conducting, semiconducting, and insulating including nanoparticles and single-walled carbon nanotubes on insulating rigid and flexible substrates. The presented approach shows great promise for making practical devices in miniaturized sensors and flexible electronics.

New Technique of High-Performance Torque Control Developed for Induction Machines

NASA Technical Reports Server (NTRS)

Kenny, Barbara H.

2003-01-01

Two forms of high-performance torque control for motor drives have been described in the literature: field orientation control and direct torque control. Field orientation control has been the method of choice for previous NASA electromechanical actuator research efforts with induction motors. Direct torque control has the potential to offer some advantages over field orientation, including ease of implementation and faster response. However, the most common form of direct torque control is not suitable for the highspeed, low-stator-flux linkage induction machines designed for electromechanical actuators with the presently available sample rates of digital control systems (higher sample rates are required). In addition, this form of direct torque control is not suitable for the addition of a high-frequency carrier signal necessary for the "self-sensing" (sensorless) position estimation technique. This technique enables low- and zero-speed position sensorless operation of the machine. Sensorless operation is desirable to reduce the number of necessary feedback signals and transducers, thus improving the reliability and reducing the mass and volume of the system. This research was directed at developing an alternative form of direct torque control known as a "deadbeat," or inverse model, solution. This form uses pulse-width modulation of the voltage applied to the machine, thus reducing the necessary sample and switching frequency for the high-speed NASA motor. In addition, the structure of the deadbeat form allows the addition of the high-frequency carrier signal so that low- and zero-speed sensorless operation is possible. The new deadbeat solution is based on using the stator and rotor flux as state variables. This choice of state variables leads to a simple graphical representation of the solution as the intersection of a constant torque line with a constant stator flux circle. Previous solutions have been expressed only in complex mathematical terms without a method to clearly visualize the solution. The graphical technique allows a more insightful understanding of the operation of the machine under various conditions.

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

NASA Technical Reports Server (NTRS)

Buck, G. M.

1991-01-01

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

Flow visualization techniques in the Airborne Laser Laboratory program

NASA Technical Reports Server (NTRS)

Walterick, R. E.; Vankuren, J. T.

1980-01-01

A turret/fairing assembly for laser applications was designed and tested. Wind tunnel testing was conducted using flow visualization techniques. The techniques used have included the methods of tufting, encapsulated liquid crystals, oil flow, sublimation and schlieren and shadowgraph photography. The results were directly applied to the design of fairing shapes for minimum drag and reduced turret buffet. In addition, the results are of primary importance to the study of light propagation paths in the near flow field of the turret cavity. Results indicate that the flow in the vicinity of the turret is an important factor for consideration in the design of suitable turret/fairing or aero-optic assemblies.

Directions for Development of the Field of Electroactive Polymer (EAP)

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2011-01-01

In last few years, the rate of development and advances in the field of EAP has accelerated significantly and it is increasingly getting closer to the point of finding them used in commercial products. Substantial development has been reported in the understanding of their drive mechanisms and the parameters that control their electro-activation behavior. Further, efforts are being made to develop mass production techniques with greatly improved actuation capability and operation durability. The recent efforts to develop energy harvesting techniques, haptic interfacing (including refreshable braille displays), and toys are further increasing the likelihood of finding niches for these materials. In this paper, the author sought to examine the potential directions for the future development of the field of EAP in relation to the state-of-the-art.

Directions for development of the field of electroactive polymer (EAP)

NASA Astrophysics Data System (ADS)

Bar-Cohen, Yoseph

2011-04-01

In last few years, the rate of development and advances in the field of EAP has accelerated significantly and it is increasingly getting closer to the point of finding them used in commercial products. Substantial development has been reported in the understanding of their drive mechanisms and the parameters that control their electro-activation behavior. Further, efforts are being made to develop mass production techniques with greatly improved actuation capability and operation durability. The recent efforts to develop energy harvesting techniques, haptic interfacing (including refreshable braille displays), and toys are further increasing the likelihood of finding niches for these materials. In this paper, the author sought to examine the potential directions for the future development of the field of EAP in relation to the state-of-the-art.

Direct measurement of local material properties within living embryonic tissues

NASA Astrophysics Data System (ADS)

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

The shaping of biological matter requires the control of its mechanical properties across multiple scales, ranging from single molecules to cells and tissues. Despite their relevance, measurements of the mechanical properties of sub-cellular, cellular and supra-cellular structures within living embryos pose severe challenges to existing techniques. We have developed a technique that uses magnetic droplets to measure the mechanical properties of complex fluids, including in situ and in vivo measurements within living embryos ,across multiple length and time scales. By actuating the droplets with magnetic fields and recording their deformation we probe the local mechanical properties, at any length scale we choose by varying the droplets' diameter. We use the technique to determine the subcellular mechanics of individual blastomeres of zebrafish embryos, and bridge the gap to the tissue scale by measuring the local viscosity and elasticity of zebrafish embryonic tissues. Using this technique, we show that embryonic zebrafish tissues are viscoelastic with a fluid-like behavior at long time scales. This technique will enable mechanobiology and mechano-transduction studies in vivo, including the study of diseases correlated with tissue stiffness, such as cancer.

Understanding Magnetic Resonance Imaging of Knee Cartilage Repair: A Focus on Clinical Relevance.

PubMed

Hayashi, Daichi; Li, Xinning; Murakami, Akira M; Roemer, Frank W; Trattnig, Siegfried; Guermazi, Ali

2017-06-01

The aims of this review article are (a) to describe the principles of morphologic and compositional magnetic resonance imaging (MRI) techniques relevant for the imaging of knee cartilage repair surgery and their application to longitudinal studies and (b) to illustrate the clinical relevance of pre- and postsurgical MRI with correlation to intraoperative images. First, MRI sequences that can be applied for imaging of cartilage repair tissue in the knee are described, focusing on comparison of 2D and 3D fast spin echo and gradient recalled echo sequences. Imaging features of cartilage repair tissue are then discussed, including conventional (morphologic) MRI and compositional MRI techniques. More specifically, imaging techniques for specific cartilage repair surgery techniques as described above, as well as MRI-based semiquantitative scoring systems for the knee cartilage repair tissue-MR Observation of Cartilage Repair Tissue and Cartilage Repair OA Knee Score-are explained. Then, currently available surgical techniques are reviewed, including marrow stimulation, osteochondral autograft, osteochondral allograft, particulate cartilage allograft, autologous chondrocyte implantation, and others. Finally, ongoing research efforts and future direction of cartilage repair tissue imaging are discussed.

Analyzing workplace exposures using direct reading instruments and video exposure monitoring techniques

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

Gressel, M.G.; Heitbrink, W.A.; Jensen, P.A.

1992-08-01

The techniques for conducting video exposure monitoring were described along with the equipment required to monitor and record worker breathing zone concentrations, the analysis of the real time exposure data using video recordings, and the use of real time concentration data from a direct reading instrument to determine the effective ventilation rate and the mixing factor of a given room at a specific time. Case studies which made use of video exposure monitoring techniques to provide information not available through integrated sampling were also discussed. The process being monitored and the methodology used to monitor the exposures were described formore » each of the case studies. The case studies included manual material weigh out, ceramic casting cleaning, dumping bags of powdered materials, furniture stripping, administration of nitrous-oxide during dental procedures, hand held sanding operation, methanol exposures in maintenance garages, brake servicing, bulk loading of railroad cars and trucks, and grinding operations.« less

Application of the CRISPR/Cas9 gene editing technique to research on functional genomes of parasites.

PubMed

Cui, Yubao; Yu, Lili

2016-12-01

The clustered regularly-interspaced short palindromic repeats (CRISPR) structural family functions as an acquired immune system in prokaryotes. Gene editing techniques have co-opted CRISPR and the associated Cas nucleases to allow for the precise genetic modification of human cells, zebrafish, mice, and other eukaryotes. Indeed, this approach has been used to induce a variety of modifications including directed insertion/deletion (InDel) of bases, gene knock-in, introduction of mutations in both alleles of a target gene, and deletion of small DNA fragments. Thus, CRISPR technology offers a precise molecular tool for directed genome modification with a range of potential applications; further, its high mutation efficiency, simple process, and low cost provide additional advantages over prior editing techniques. This paper will provide an overview of the basic structure and function of the CRISPR gene editing system as well as current and potential applications to research on parasites. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Microscale Patterning of Thermoplastic Polymer Surfaces by Selective Solvent Swelling

PubMed Central

Rahmanian, Omid; Chen, Chien-Fu; DeVoe, Don L.

2012-01-01

A new method for the fabrication of microscale features in thermoplastic substrates is presented. Unlike traditional thermoplastic microfabrication techniques, in which bulk polymer is displaced from the substrate by machining or embossing, a unique process termed orogenic microfabrication has been developed in which selected regions of a thermoplastic surface are raised from the substrate by an irreversible solvent swelling mechanism. The orogenic technique allows thermoplastic surfaces to be patterned using a variety of masking methods, resulting in three-dimensional features that would be difficult to achieve through traditional microfabrication methods. Using cyclic olefin copolymer as a model thermoplastic material, several variations of this process are described to realize growth heights ranging from several nanometers to tens of microns, with patterning techniques include direct photoresist masking, patterned UV/ozone surface passivation, elastomeric stamping, and noncontact spotting. Orogenic microfabrication is also demonstrated by direct inkjet printing as a facile photolithography-free masking method for rapid desktop thermoplastic microfabrication. PMID:22900539

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

Back to Basics: Working with Young Children with Autism in Inclusive Classrooms

ERIC Educational Resources Information Center

Deris, Aaron R.; Di Carlo, Cynthia F.

2013-01-01

Young children with autism benefit from various adaptations made to an early childhood classroom. This article includes modifications for both teacher-directed and child-initiated activities. Adaptations are given for the classroom environment, daily schedule, sensory needs, transitions and general teaching strategies. The techniques described are…

Progress toward a cosmic dust collection facility on space station

NASA Technical Reports Server (NTRS)

Mackinnon, Ian D. R. (Editor); Carey, William C. (Editor)

1987-01-01

Scientific and programmatic progress toward the development of a cosmic dust collection facility (CDCF) for the proposed space station is documented. Topics addressed include: trajectory sensor concepts; trajectory accuracy and orbital evolution; CDCF pointing direction; development of capture devices; analytical techniques; programmatic progress; flight opportunities; and facility development.

76 FR 20996 - Agency Information Collection Activities: Extension of an Existing Information Collection...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-14

...-training institution, to include approved private elementary and secondary schools and public secondary..., mechanical, or other technological collection techniques or other forms of information technology, e.g... directs the Attorney General, in consultation with the Secretary of State and the Secretary of Education...

Direct and Collateral Effects of the First Step to Success Program

ERIC Educational Resources Information Center

Sprague, Jeffrey; Perkins, Kindle

2009-01-01

First Step to Success is a multicomponent behavioral program for at-risk children who show signs of antisocial behavior at the point of school entry. The program incorporates behavioral intervention techniques, including praise and feedback, positive reinforcement, social skills training, teacher and parent collaboration, and time-out/response…

Niigugim Qalgadangis (Atkan Food).

ERIC Educational Resources Information Center

Dirks, Moses; Dirks, Lydia

A history of food gathering and food preparation techniques of Alaska natives on Atka Island in the Aleutians are presented in Western Aleut and English with illustrations by J. Leslie Boffa and Mike Dirks. Directions are given for preparing: various plants, including wild rice; salted, dried, or smoked fish; baked flour; fried dough; boiled…

Highway Vehicle Retrofit Evaluation : Phase I. Analysis and Preliminary Evaluation Results. Volume 2. Sections 4 through 13 and Appendix.

DOT National Transportation Integrated Search

1975-11-01

More than 20 representative classes of retrofit devices/concepts/techniques, including more than 130 specific items, were examined in the course of the study. A major portion of the analysis effort was directed to the evaluation of 16 advanced, novel...

New Technologies Extend the Reach of Many College Fund Raisers.

ERIC Educational Resources Information Center

Nicklin, Julie L.

1992-01-01

Increasingly, colleges are using new technologies, often expensive, to improve fund-raising capacity among small-scale donors. Techniques include computerized screening of prospective donors based on personal information, automatic dialing and phone-bank worker training, and sophisticated direct-mail tactics. Concern about privacy and loss of the…

Direct Analysis of Samples of Various Origin and Composition Using Specific Types of Mass Spectrometry.

PubMed

Byliński, Hubert; Gębicki, Jacek; Dymerski, Tomasz; Namieśnik, Jacek

2017-07-04

One of the major sources of error that occur during chemical analysis utilizing the more conventional and established analytical techniques is the possibility of losing part of the analytes during the sample preparation stage. Unfortunately, this sample preparation stage is required to improve analytical sensitivity and precision. Direct techniques have helped to shorten or even bypass the sample preparation stage; and in this review, we comment of some of the new direct techniques that are mass-spectrometry based. The study presents information about the measurement techniques using mass spectrometry, which allow direct sample analysis, without sample preparation or limiting some pre-concentration steps. MALDI - MS, PTR - MS, SIFT - MS, DESI - MS techniques are discussed. These solutions have numerous applications in different fields of human activity due to their interesting properties. The advantages and disadvantages of these techniques are presented. The trends in development of direct analysis using the aforementioned techniques are also presented.

Placement of direct composite veneers utilizing a silicone buildup guide and intraoral mock-up.

PubMed

Behle, C

2000-04-01

The indications for direct composite resins have recently been expanded to include predictable and convenient application in the aesthetic zone. The availability of composite materials with improved physical and optical characteristics facilitates the development of enhanced aesthetics while maintaining vital function. This article presents a simplified technique that combines function with aesthetics by utilizing an intraoral composite mock-up for initial communication and a lingual/incisal silicone stent of the mock-up to transfer the information to the definitive restorative buildup.

Digital signal processing and control and estimation theory -- Points of tangency, area of intersection, and parallel directions

NASA Technical Reports Server (NTRS)

Willsky, A. S.

1976-01-01

A number of current research directions in the fields of digital signal processing and modern control and estimation theory were studied. Topics such as stability theory, linear prediction and parameter identification, system analysis and implementation, two-dimensional filtering, decentralized control and estimation, image processing, and nonlinear system theory were examined in order to uncover some of the basic similarities and differences in the goals, techniques, and philosophy of the two disciplines. An extensive bibliography is included.

Seamless, axially aligned, fiber tubes, meshes, microbundles and gradient biomaterial constructs

PubMed Central

Elia, Roberto; Firpo, Matthew A.; Kaplan, David L.; Peattie, Robert A.

2012-01-01

A new electrospinning apparatus was developed to generate nanofibrous materials with improved organizational control. The system functions by oscillating the deposition signal (ODS) of multiple collectors, allowing significantly improved nanofiber control by manipulating the electric field which drives the electrospinning process. Other electrospinning techniques designed to impart deposited fiber organizational control, such as rotating mandrels or parallel collector systems, do not generate seamless constructs with high quality alignment in sizes large enough for medical devices. In contrast, the ODS collection system produces deposited fiber networks with highly pure alignment in a variety of forms and sizes, including flat (8 × 8 cm2), tubular (1.3 cm diameter), or rope-like microbundle (45 μm diameter) samples. Additionally, the mechanism of our technique allows for scale-up beyond these dimensions. The ODS collection system produced 81.6 % of fibers aligned within 5° of the axial direction, nearly a four-fold improvement over the rotating mandrel technique. The meshes produced from the 9 % (w/v) fibroin/PEO blend demonstrated significant mechanical anisotropy due to the fiber alignment. In 37 °C PBS, aligned samples produced an ultimate tensile strength of 16.47 ± 1.18 MPa, a Young's modulus of 37.33 MPa, and a yield strength of 7.79 ± 1.13 MPa. The material was 300 % stiffer when extended in the direction of fiber alignment and required 20 times the amount of force to be deformed, compared to aligned meshes extended perpendicular to the fiber direction. The ODS technique could be applied to any electrospinnable polymer to overcome the more limited uniformity and induced mechanical strain of rotating mandrel techniques, and greatly surpasses the limited length of standard parallel collector techniques. PMID:22890517

Coherent nonlinear optical imaging: beyond fluorescence microscopy.

PubMed

Min, Wei; Freudiger, Christian W; Lu, Sijia; Xie, X Sunney

2011-01-01

The quest for ultrahigh detection sensitivity with spectroscopic contrasts other than fluorescence has led to various novel approaches to optical microscopy of biological systems. Coherent nonlinear optical imaging, especially the recently developed nonlinear dissipation microscopy (including stimulated Raman scattering and two-photon absorption) and pump-probe microscopy (including excited-state absorption, stimulated emission, and ground-state depletion), provides new image contrasts for nonfluorescent species. Thanks to the high-frequency modulation transfer scheme, these imaging techniques exhibit superb detection sensitivity. By directly interrogating vibrational and/or electronic energy levels of molecules, they offer high molecular specificity. Here we review the underlying principles and excitation and detection schemes, as well as exemplary biomedical applications of this emerging class of molecular imaging techniques.

Coloring the FITS Universe

NASA Astrophysics Data System (ADS)

Levay, Z. G.

2004-12-01

A new, freely-available accessory for Adobe's widely-used Photoshop image editing software makes it much more convenient to produce presentable images directly from FITS data. It merges a fully-functional FITS reader with an intuitive user interface and includes fully interactive flexibility in scaling data. Techniques for producing attractive images from astronomy data using the FITS plugin will be presented, including the assembly of full-color images. These techniques have been successfully applied to producing colorful images for public outreach with data from the Hubble Space Telescope and other major observatories. Now it is much less cumbersome for students or anyone not experienced with specialized astronomical analysis software, but reasonably familiar with digital photography, to produce useful and attractive images.

Numerical method and FORTRAN program for the solution of an axisymmetric electrostatic collector design problem

NASA Technical Reports Server (NTRS)

Reese, O. W.

1972-01-01

The numerical calculation is described of the steady-state flow of electrons in an axisymmetric, spherical, electrostatic collector for a range of boundary conditions. The trajectory equations of motion are solved alternately with Poisson's equation for the potential field until convergence is achieved. A direct (noniterative) numerical technique is used to obtain the solution to Poisson's equation. Space charge effects are included for initial current densities as large as 100 A/sq cm. Ways of dealing successfully with the difficulties associated with these high densities are discussed. A description of the mathematical model, a discussion of numerical techniques, results from two typical runs, and the FORTRAN computer program are included.

Supercomputer optimizations for stochastic optimal control applications

NASA Technical Reports Server (NTRS)

Chung, Siu-Leung; Hanson, Floyd B.; Xu, Huihuang

1991-01-01

Supercomputer optimizations for a computational method of solving stochastic, multibody, dynamic programming problems are presented. The computational method is valid for a general class of optimal control problems that are nonlinear, multibody dynamical systems, perturbed by general Markov noise in continuous time, i.e., nonsmooth Gaussian as well as jump Poisson random white noise. Optimization techniques for vector multiprocessors or vectorizing supercomputers include advanced data structures, loop restructuring, loop collapsing, blocking, and compiler directives. These advanced computing techniques and superconducting hardware help alleviate Bellman's curse of dimensionality in dynamic programming computations, by permitting the solution of large multibody problems. Possible applications include lumped flight dynamics models for uncertain environments, such as large scale and background random aerospace fluctuations.

Veterinary Aspects of Bird of Prey Reproduction.

PubMed

Bailey, Tom A; Lierz, Michael

2017-05-01

Captive breeding has contributed to successful restoration of many species of birds of prey. Avicultural techniques pioneered by raptor breeders include double clutching, direct fostering, cross-fostering, hatch and switch, hacking, imprinting male and female falcons for semen collection, and artificial insemination techniques. However, reproductive failure occurs related to management problems, including hygiene measures, food quality issues, breeding flock structure, or individual health issues of breeding birds. These may result in non-egg laying females, low-quality eggs, or infertile eggs caused by male infertility. Veterinary care of breeding collections is extremely important. This article provides an overview of veterinary involvement in raptor breeding projects. Copyright © 2016 Elsevier Inc. All rights reserved.

Metal Additive Manufacturing: A Review of Mechanical Properties

NASA Astrophysics Data System (ADS)

Lewandowski, John J.; Seifi, Mohsen

2016-07-01

This article reviews published data on the mechanical properties of additively manufactured metallic materials. The additive manufacturing techniques utilized to generate samples covered in this review include powder bed fusion (e.g., EBM, SLM, DMLS) and directed energy deposition (e.g., LENS, EBF3). Although only a limited number of metallic alloy systems are currently available for additive manufacturing (e.g., Ti-6Al-4V, TiAl, stainless steel, Inconel 625/718, and Al-Si-10Mg), the bulk of the published mechanical properties information has been generated on Ti-6Al-4V. However, summary tables for published mechanical properties and/or key figures are included for each of the alloys listed above, grouped by the additive technique used to generate the data. Published values for mechanical properties obtained from hardness, tension/compression, fracture toughness, fatigue crack growth, and high cycle fatigue are included for as-built, heat-treated, and/or HIP conditions, when available. The effects of test orientation/build direction on properties, when available, are also provided, along with discussion of the potential source(s) (e.g., texture, microstructure changes, defects) of anisotropy in properties. Recommendations for additional work are also provided.

Airborne laser systems for atmospheric sounding in the near infrared

NASA Astrophysics Data System (ADS)

Sabatini, Roberto; Richardson, Mark A.; Jia, Huamin; Zammit-Mangion, David

2012-06-01

This paper presents new techniques for atmospheric sounding using Near Infrared (NIR) laser sources, direct detection electro-optics and passive infrared imaging systems. These techniques allow a direct determination of atmospheric extinction and, through the adoption of suitable inversion algorithms, the indirect measurement of some important natural and man-made atmospheric constituents, including Carbon Dioxide (CO2). The proposed techniques are suitable for remote sensing missions performed by using aircraft, satellites, Unmanned Aerial Vehicles (UAV), parachute/gliding vehicles, Roving Surface Vehicles (RSV), or Permanent Surface Installations (PSI). The various techniques proposed offer relative advantages in different scenarios. All are based on measurements of the laser energy/power incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Experimental results are presented relative to 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 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 above ground level. Future activities are planned to validate the atmospheric retrieval algorithms developed for CO2 column density measurements, with emphasis on aircraft related emissions at airports and other high air-traffic density environments.

Computational intelligence techniques in bioinformatics.

PubMed

Hassanien, Aboul Ella; Al-Shammari, Eiman Tamah; Ghali, Neveen I

2013-12-01

Computational intelligence (CI) is a well-established paradigm with current systems having many of the characteristics of biological computers and capable of performing a variety of tasks that are difficult to do using conventional techniques. It is a methodology involving adaptive mechanisms and/or an ability to learn that facilitate intelligent behavior in complex and changing environments, such that the system is perceived to possess one or more attributes of reason, such as generalization, discovery, association and abstraction. The objective of this article is to present to the CI and bioinformatics research communities some of the state-of-the-art in CI applications to bioinformatics and motivate research in new trend-setting directions. In this article, we present an overview of the CI techniques in bioinformatics. We will show how CI techniques including neural networks, restricted Boltzmann machine, deep belief network, fuzzy logic, rough sets, evolutionary algorithms (EA), genetic algorithms (GA), swarm intelligence, artificial immune systems and support vector machines, could be successfully employed to tackle various problems such as gene expression clustering and classification, protein sequence classification, gene selection, DNA fragment assembly, multiple sequence alignment, and protein function prediction and its structure. We discuss some representative methods to provide inspiring examples to illustrate how CI can be utilized to address these problems and how bioinformatics data can be characterized by CI. Challenges to be addressed and future directions of research are also presented and an extensive bibliography is included. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Modified, Direct Neck Lift Technique: The Cervical Wave-Plasty

PubMed Central

Castel, Nikki; Parsa, Natalie Niloufar

2016-01-01

Background Major problems with cervicoplasty by direct skin excision include the subjective nature of skin markings preoperatively and the confusing array of procedures offered. This technique incorporates curved incisions, resulting in a wave-like scar, which is why the procedure is called a "wave-plasty". Methods This prospective study includes 37 patients who underwent wave-plasty procedures from 2004 to 2015. Skin pinching technique was used to mark the anterior neck preoperatively in a reproducible fashion. Intra-operatively, redundant skin was excised, along with excess fat when necessary, and closed to form a wave-shaped scar. Patients were asked to follow up at 1 week, 6 weeks, and 6 months after surgery. Results The mean operation time was 70.8 minutes. The majority (81.3%) was satisfied with their progress. On a scale of 1 to 10 (1 being the worst, and 10 being the best), the scars were objectively graded on average 5.5 when viewed from the front and 7.3 when seen from the side 6 months after surgery. Complications consisted of one partial wound dehiscence (2.3%), one incidence of hypertrophic scarring (2.3%), and two cases of under-resection requiring revision (5.4%). Conclusions In select patients, surgical rejuvenation of the neck may be obtained through wave-like incisions to remove redundant cervical skin when other options are not available. The technique is reproducible, easily teachable and carries low morbidity and high patient satisfaction in carefully chosen patients. PMID:27019811

Direct dating of human fossils.

PubMed

Grün, Rainer

2006-01-01

The methods that can be used for the direct dating of human remains comprise of radiocarbon, U-series, electron spin resonance (ESR), and amino acid racemization (AAR). This review gives an introduction to these methods in the context of dating human bones and teeth. Recent advances in ultrafiltration techniques have expanded the dating range of radiocarbon. It now seems feasible to reliably date bones up to 55,000 years. New developments in laser ablation mass spectrometry permit the in situ analysis of U-series isotopes, thus providing a rapid and virtually non-destructive dating method back to about 300,000 years. This is of particular importance when used in conjunction with non-destructive ESR analysis. New approaches in AAR analysis may lead to a renaissance of this method. The potential and present limitations of these direct dating techniques are discussed for sites relevant to the reconstruction of modern human evolution, including Florisbad, Border Cave, Tabun, Skhul, Qafzeh, Vindija, Banyoles, and Lake Mungo. (c) 2006 Wiley-Liss, Inc.

Preparation and characterization of silver nanoparticles homogenous thin films

NASA Astrophysics Data System (ADS)

Hegazy, Maroof A.; Borham, E.

2018-06-01

The wet chemical method by metal salt reduction has been widely used to synthesize nanoparticles. Accordingly the silver nitrate used as silver precursor and sodium borohydrate as reduction agent. The silver nanoparticles were characterized by different characterization techniques including UV-VIS spectrometry, Transmission electron microscope (TEM), and Zeta potential technique. Thin films of the colloidal solution were fabricated using direct precipitation technique on ITO glass, silicon substrate and commercial glass substrate and characterized by imaging technique. The absorption peak of the silver nanoparticles colloidal solution was around 400 nm. The TEM images indicate that the silver nanoparticles had spherical shape and their sizes were from 10 to 17 nm. The particle size of the silver nanoparticles was confirmed by Zeta potential technique. The imaging technique indicated that the homogeneous distribution of the colloidal silver solution thin film on the silicon substrate was stronger than the ITO glass and inhomogeneous film was emerged on the commercial glass.

Minimally Invasive Calcaneal Displacement Osteotomy Site Using a Reference Kirschner Wire: A Technique Tip.

PubMed

Lee, Moses; Guyton, Gregory P; Zahoor, Talal; Schon, Lew C

2016-01-01

As a standard open approach, the lateral oblique incision has been widely used for calcaneal displacement osteotomy. However, just as with other orthopedic procedures that use an open approach, complications, including wound healing problems and neurovascular injury in the heel, have been reported. To help avoid these limitations, a percutaneous technique using a Shannon burr for calcaneal displacement osteotomy was introduced. However, relying on a free-hand technique without direct visualization at the osteotomy site has been a major obstacle for this technique. To address this problem, we developed a technical tip using a reference Kirschner wire. A reference Kirschner wire technique provides a reliable and accurate guide for minimally invasive calcaneal displacement osteotomy. Also, the technique should be easy to learn for surgeons new to the procedure. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

The principles and conduct of anaesthesia for emergency surgery.

PubMed

Gray, L D; Morris, C

2013-01-01

In this second article we examine the principles underlying delivery of the components of anaesthesia. Topics considered include anaesthetic technique, management of the airway and lung ventilation, induction and maintenance of anaesthesia, patient monitoring including the place of cardiac output devices. We summarise recent research on the management of shock and sepsis syndromes including goal directed therapy and examine some controversies around intravenous fluid therapy. Finally, we discuss intra-operative awareness and challenges during emergence including peri-operative cognitive dysfunction. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.

Data Flow Analysis and Visualization for Spatiotemporal Statistical Data without Trajectory Information.

PubMed

Kim, Seokyeon; Jeong, Seongmin; Woo, Insoo; Jang, Yun; Maciejewski, Ross; Ebert, David S

2018-03-01

Geographic visualization research has focused on a variety of techniques to represent and explore spatiotemporal data. The goal of those techniques is to enable users to explore events and interactions over space and time in order to facilitate the discovery of patterns, anomalies and relationships within the data. However, it is difficult to extract and visualize data flow patterns over time for non-directional statistical data without trajectory information. In this work, we develop a novel flow analysis technique to extract, represent, and analyze flow maps of non-directional spatiotemporal data unaccompanied by trajectory information. We estimate a continuous distribution of these events over space and time, and extract flow fields for spatial and temporal changes utilizing a gravity model. Then, we visualize the spatiotemporal patterns in the data by employing flow visualization techniques. The user is presented with temporal trends of geo-referenced discrete events on a map. As such, overall spatiotemporal data flow patterns help users analyze geo-referenced temporal events, such as disease outbreaks, crime patterns, etc. To validate our model, we discard the trajectory information in an origin-destination dataset and apply our technique to the data and compare the derived trajectories and the original. Finally, we present spatiotemporal trend analysis for statistical datasets including twitter data, maritime search and rescue events, and syndromic surveillance.

[Recent Development of Atomic Spectrometry in China].

PubMed

Xiao, Yuan-fang; Wang, Xiao-hua; Hang, Wei

2015-09-01

As an important part of modern analytical techniques, atomic spectrometry occupies a decisive status in the whole analytical field. The development of atomic spectrometry also reflects the continuous reform and innovation of analytical techniques. In the past fifteen years, atomic spectrometry has experienced rapid development and been applied widely in many fields in China. This review has witnessed its development and remarkable achievements. It contains several directions of atomic spectrometry, including atomic emission spectrometry (AES), atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS), X-ray fluorescence spectrometry (XRF), and atomic mass spectrometry (AMS). Emphasis is put on the innovation of the detection methods and their applications in related fields, including environmental samples, biological samples, food and beverage, and geological materials, etc. There is also a brief introduction to the hyphenated techniques utilized in atomic spectrometry. Finally, the prospects of atomic spectrometry in China have been forecasted.

A technique for computation of noise temperature due to a beam waveguide shroud

NASA Technical Reports Server (NTRS)

Veruttipong, W.; Franco, M. M.

1993-01-01

Direct analytical computation of the noise temperature of real beam waveguide (BWG) systems, including all mirrors and the surrounding shroud, is an extremely complex problem and virtually impossible to achieve. Yet the DSN antennas are required to be ultra low-noise in order to be effective, and a reasonably accurate prediction is essential. This article presents a relatively simple technique to compute a real BWG system noise temperature by combining analytical techniques with data from experimental tests. Specific expressions and parameters for X-band (8.45-GHz) BWG noise computation are obtained for DSS 13 and DSS 24, now under construction. These expressions are also valid for various conditions of the BWG feed systems, including horn sizes and positions, and mirror sizes, curvatures, and positions. Parameters for S- and Ka-bands (2.3 and 32.0 GHz) have not been determined; however, those can be obtained following the same procedure as for X-band.

A Review on Microdialysis Calibration Methods: the Theory and Current Related Efforts.

PubMed

Kho, Chun Min; Enche Ab Rahim, Siti Kartini; Ahmad, Zainal Arifin; Abdullah, Norazharuddin Shah

2017-07-01

Microdialysis is a sampling technique first introduced in the late 1950s. Although this technique was originally designed to study endogenous compounds in animal brain, it is later modified to be used in other organs. Additionally, microdialysis is not only able to collect unbound concentration of compounds from tissue sites; this technique can also be used to deliver exogenous compounds to a designated area. Due to its versatility, microdialysis technique is widely employed in a number of areas, including biomedical research. However, for most in vivo studies, the concentration of substance obtained directly from the microdialysis technique does not accurately describe the concentration of the substance on-site. In order to relate the results collected from microdialysis to the actual in vivo condition, a calibration method is required. To date, various microdialysis calibration methods have been reported, with each method being capable to provide valuable insights of the technique itself and its applications. This paper aims to provide a critical review on various calibration methods used in microdialysis applications, inclusive of a detailed description of the microdialysis technique itself to start with. It is expected that this article shall review in detail, the various calibration methods employed, present examples of work related to each calibration method including clinical efforts, plus the advantages and disadvantages of each of the methods.

A Comparison of implant impression precision: Different materials and techniques

PubMed Central

Tabesh, Mahtab; Alikhasi, Marzieh

2018-01-01

Background Precision of implant impressions is a prerequisite for long-term success of implant supported prostheses. Impression materials and impression techniques are two important factors that impression precision relies on. Material and Methods A model of edentulous maxilla containing four implants inserted by All-on-4 guide was constructed. Seventy two impressions using polyether (PE), polyvinyl siloxane (PVS), and vinyl siloxanether (VSE) materials with direct and indirect techniques were made (n=12). Coordinates of implants in casts were measured using coordinate measuring machine (CMM). Data were analyzed with ANOVA; t-test and Tukey test were used for post hoc. Results With two-way ANOVA, mean values of linear displacements of implants were significantly different among materials and techniques. One-way ANOVA and Tukey showed significant difference between PE and VSE (P=0.019), PE and PVS (P=0.002) in direct technique, and between PVS and PE (P<0.001), PVS and VSE (P<0.001) in indirect technique. One-way ANOVA and t-test showed significant difference between the two techniques in PVS groups (P<0.001) and in PE groups (P=0.02). Two-way ANOVA showed mean values of rotational displacement of implants were significantly different among materials. One-way ANOVA and Tukey test showed significant difference between PVS and PE (P=0.001) and between PVS and VSE (P=0.012) in indirect groups. Conclusions On the basis of the results, when deciding on the material to make an impression of implants, PE is recommended for direct technique while PE and VSE are recommended for indirect technique. Recommended technique for VSE is either direct or indirect; and for PE and PVS is direct. Key words:Polyvinyl siloxane, polyether, vinyl siloxanether, direct technique, indirect technique, All-on-4, coordinate measuring machine. PMID:29670733

Accuracy of cast posts fabricated by the direct and the indirect techniques.

PubMed

Rayyan, Mohammad R; Aldossari, Roa'a A; Alsadun, Sarah F; Hijazy, Fatimah R

2016-09-01

Patterns for custom cast posts and cores can be fabricated either by the direct or the indirect technique. Which technique is more accurate is unknown. The purpose of this in vitro study was to investigate the effect of pattern fabrication technique on the accuracy of post fit. Ten intact extracted premolar teeth with a single canal and similar dimensions received root canal treatment. The teeth were sectioned 2 mm above the cementoenamel junction. A total of 20 cast post and core patterns, 2 for each tooth, were fabricated, 10 with the direct technique and 10 with the indirect technique. Patterns were cast to produce 20 cast post and cores. Each tooth was scanned using a microcomputed tomography (μCT) system with a resolution of 14.5 μm, once with the post of the direct technique and once with the post of the indirect technique. Ct analyzer software was used to calculate the overall space between the post and canal walls and the space areas in 3 different standardized sections. The Student paired t test was used to determine any significant difference in the scores of the groups. The overall space between the canal walls and posts made with the direct technique ranged between 7.86 and 17.39 mm(3), with a mean value of 12.25 mm(3), whereas with the indirect technique, the space ranged between 6.68 and 18.02 mm(3), with a mean of 11.92 mm(3). No significant differences were found between the results of either technique (P>.05). Within the limitations of this study, neither the indirect nor direct pattern fabrication technique influenced the accuracy of post fitting. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Covariance mapping techniques

NASA Astrophysics Data System (ADS)

Frasinski, Leszek J.

2016-08-01

Recent technological advances in the generation of intense femtosecond pulses have made covariance mapping an attractive analytical technique. The laser pulses available are so intense that often thousands of ionisation and Coulomb explosion events will occur within each pulse. To understand the physics of these processes the photoelectrons and photoions need to be correlated, and covariance mapping is well suited for operating at the high counting rates of these laser sources. Partial covariance is particularly useful in experiments with x-ray free electron lasers, because it is capable of suppressing pulse fluctuation effects. A variety of covariance mapping methods is described: simple, partial (single- and multi-parameter), sliced, contingent and multi-dimensional. The relationship to coincidence techniques is discussed. Covariance mapping has been used in many areas of science and technology: inner-shell excitation and Auger decay, multiphoton and multielectron ionisation, time-of-flight and angle-resolved spectrometry, infrared spectroscopy, nuclear magnetic resonance imaging, stimulated Raman scattering, directional gamma ray sensing, welding diagnostics and brain connectivity studies (connectomics). This review gives practical advice for implementing the technique and interpreting the results, including its limitations and instrumental constraints. It also summarises recent theoretical studies, highlights unsolved problems and outlines a personal view on the most promising research directions.

Preparation of gold nanocluster bioconjugates for electron microscopy.

PubMed

Heinecke, Christine L; Ackerson, Christopher J

2013-01-01

In this chapter, we describe types of gold nanoparticle-biomolecule conjugates and their use in electron microscopy. Included are two detailed protocols for labeling an IgG antibody with gold monolayer protected clusters. The first approach is a direct bonding approach that utilizes the ligand place exchange reaction. The second approach describes NHS-EDC coupling of Au(144)(pMBA)(60) with IgG. Also included are various characterization techniques for determining labeling efficiency.

Continuous All-Optical Deceleration and Single-Photon Cooling of Molecular Beams

DTIC Science & Technology

2014-02-21

PHYSICAL REVIEW A 89 , 023425 (2014) Continuous all-optical deceleration and single-photon cooling of molecular beams A. M. Jayich,1 A. C. Vutha,2 M...details including multilevel numerical simulations of strontium monohydride. These techniques are applicable to a large number of molecular species and...molecules that are considered difficult to directly laser cool—a class that includes many 1050-2947/2014/ 89 (2)/023425(8) 023425-1 ©2014 American

Quiet engine program: Turbine noise suppression. -Volume 1: General treatment evaluation and measurement techniques

NASA Technical Reports Server (NTRS)

Clemons, A.; Hehmann, H.; Radecki, K.

1973-01-01

Acoustic treatment was developed for jet engine turbine noise suppression. Acoustic impedance and duct transmission loss measurements were made for various suppression systems. An environmental compatibility study on several material types having suppression characteristics is presented. Two sets of engine hardware were designed and are described along with engine test results which include probe, farfield, near field, and acoustic directional array data. Comparisons of the expected and the measured suppression levels are given as well as a discussion of test results and design techniques.

Quality assessment and control of finite element solutions

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Babuska, Ivo

1987-01-01

Status and some recent developments in the techniques for assessing the reliability of finite element solutions are summarized. Discussion focuses on a number of aspects including: the major types of errors in the finite element solutions; techniques used for a posteriori error estimation and the reliability of these estimators; the feedback and adaptive strategies for improving the finite element solutions; and postprocessing approaches used for improving the accuracy of stresses and other important engineering data. Also, future directions for research needed to make error estimation and adaptive movement practical are identified.

Apparatus description and data analysis of a radiometric technique for measurements of spectral and total normal emittance

NASA Technical Reports Server (NTRS)

Edwards, S. F.; Kantsios, A. G.; Voros, J. P.; Stewart, W. F.

1975-01-01

The development of a radiometric technique for determining the spectral and total normal emittance of materials heated to temperatures of 800, 1100, and 1300 K by direct comparison with National Bureau of Standards (NBS) reference specimens is discussed. Emittances are measured over the spectral range of 1 to 15 microns and are statistically compared with NBS reference specimens. Results are included for NBS reference specimens, Rene 41, alundum, zirconia, AISI type 321 stainless steel, nickel 201, and a space-shuttle reusable surface insulation.

Reflectance spectroscopy in planetary science: Review and strategy for the future

NASA Technical Reports Server (NTRS)

Mccord, Thomas B. (Editor)

1987-01-01

Reflectance spectroscopy is a remote sensing technique used to study the surfaces and atmospheres of solar system bodies. It provides first-order information on the presence and amounts of certain ions, molecules, and minerals on a surface or in an atmosphere. Reflectance spectroscopy has become one of the most important investigations conducted on most current and planned NASA Solar System Exploration Program space missions. This book reviews the field of reflectance spectroscopy, including information on the scientific technique, contributions, present conditions, and future directions and needs.

Artificial electromagnetism for neutral atoms: Escher staircase and Laughlin liquids

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

Mueller, Erich J.

2004-10-01

We present a method for creating fields that couple to neutral atoms in the same way that electromagnetic fields couple to charged particles. We show that this technique opens the door for a range of neutral atom experiments, including probing the interplay between periodic potentials and quantum Hall effects. Furthermore, we propose, and analyze, seemingly paradoxical geometries which can be engineered through these techniques. For example, we show how to create a ring of sites where an atom continuously reduces its potential energy by moving in a clockwise direction.

Charged-particle emission tomography

PubMed Central

Ding, Yijun; Caucci, Luca; Barrett, Harrison H.

2018-01-01

Purpose Conventional charged-particle imaging techniques —such as autoradiography —provide only two-dimensional (2D) black ex vivo images of thin tissue slices. In order to get volumetric information, images of multiple thin slices are stacked. This process is time consuming and prone to distortions, as registration of 2D images is required. We propose a direct three-dimensional (3D) autoradiography technique, which we call charged-particle emission tomography (CPET). This 3D imaging technique enables imaging of thick tissue sections, thus increasing laboratory throughput and eliminating distortions due to registration. CPET also has the potential to enable in vivo charged-particle imaging with a window chamber or an endoscope. Methods Our approach to charged-particle emission tomography uses particle-processing detectors (PPDs) to estimate attributes of each detected particle. The attributes we estimate include location, direction of propagation, and/or the energy deposited in the detector. Estimated attributes are then fed into a reconstruction algorithm to reconstruct the 3D distribution of charged-particle-emitting radionuclides. Several setups to realize PPDs are designed. Reconstruction algorithms for CPET are developed. Results Reconstruction results from simulated data showed that a PPD enables CPET if the PPD measures more attributes than just the position from each detected particle. Experiments showed that a two-foil charged-particle detector is able to measure the position and direction of incident alpha particles. Conclusions We proposed a new volumetric imaging technique for charged-particle-emitting radionuclides, which we have called charged-particle emission tomography (CPET). We also proposed a new class of charged-particle detectors, which we have called particle-processing detectors (PPDs). When a PPD is used to measure the direction and/or energy attributes along with the position attributes, CPET is feasible. PMID:28370094

Charged-particle emission tomography.

PubMed

Ding, Yijun; Caucci, Luca; Barrett, Harrison H

2017-06-01

Conventional charged-particle imaging techniques - such as autoradiography - provide only two-dimensional (2D) black ex vivo images of thin tissue slices. In order to get volumetric information, images of multiple thin slices are stacked. This process is time consuming and prone to distortions, as registration of 2D images is required. We propose a direct three-dimensional (3D) autoradiography technique, which we call charged-particle emission tomography (CPET). This 3D imaging technique enables imaging of thick tissue sections, thus increasing laboratory throughput and eliminating distortions due to registration. CPET also has the potential to enable in vivo charged-particle imaging with a window chamber or an endoscope. Our approach to charged-particle emission tomography uses particle-processing detectors (PPDs) to estimate attributes of each detected particle. The attributes we estimate include location, direction of propagation, and/or the energy deposited in the detector. Estimated attributes are then fed into a reconstruction algorithm to reconstruct the 3D distribution of charged-particle-emitting radionuclides. Several setups to realize PPDs are designed. Reconstruction algorithms for CPET are developed. Reconstruction results from simulated data showed that a PPD enables CPET if the PPD measures more attributes than just the position from each detected particle. Experiments showed that a two-foil charged-particle detector is able to measure the position and direction of incident alpha particles. We proposed a new volumetric imaging technique for charged-particle-emitting radionuclides, which we have called charged-particle emission tomography (CPET). We also proposed a new class of charged-particle detectors, which we have called particle-processing detectors (PPDs). When a PPD is used to measure the direction and/or energy attributes along with the position attributes, CPET is feasible. © 2017 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

A micromotor based on polymer single crystals and nanoparticles: toward functional versatility.

PubMed

Liu, Mei; Liu, Limei; Gao, Wenlong; Su, Miaoda; Ge, Ya; Shi, Lili; Zhang, Hui; Dong, Bin; Li, Christopher Y

2014-08-07

We report a multifunctional micromotor fabricated by the self-assembly technique using multifunctional materials, i.e. polymer single crystals and nanoparticles, as basic building blocks. Not only can this micromotor achieve autonomous and directed movement, it also possesses unprecedented functions, including enzymatic degradation-induced micromotor disassembly, sustained release and molecular detection.

75 FR 63472 - Notice of Public Information Collection(s) Being Reviewed by the Federal Communications...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

... FEDERAL COMMUNICATIONS COMMISSION Notice of Public Information Collection(s) Being Reviewed by the..., including the use of automated collection techniques or other forms of information technology; and (e) ways... Sec. 103(c)(1) directs the Commission to collect information on the type of technology used to provide...

Joys and Mysteries: An Interview with Debra W. Fritts.

ERIC Educational Resources Information Center

Gamble, Harriet

2002-01-01

Presents an interview with Debra W. Fritts, a ceramic artist who created handbuilt terra-cotta sculptures. Focuses on topics, such as her childhood, her beginning interests in art, her teaching, her growth as an artist, and the techniques she uses when creating her sculptures. Includes directions for a rattle project. (CMK)

Improving Articulation and Transfer Relationships. New Directions for Community Colleges, Number 39.

ERIC Educational Resources Information Center

Kintzer, Frederick C., Ed.

1982-01-01

With the intent of revitalizing the study of educational articulation and transfer, this collection of essays describes and assesses the current status of transfer education, points to particular problems and concerns, and highlights specific techniques, activities, and practices. The volume includes "The Transfer Function--One of Many,"…

Remote multi-position information gathering system and method

DOEpatents

Hirschfeld, Tomas B.

1986-01-01

A technique for gathering specific information from various remote locations, especially fluorimetric information characteristic of particular materials at the various locations is disclosed herein. This technique uses a single source of light disposed at still a different, central location and an overall optical network including an arrangement of optical fibers cooperating with the light source for directing individual light beams into the different information bearing locations. The incoming light beams result in corresponding displays of light, e.g., fluorescent light, containing the information to be obtained. The optical network cooperates with these light displays at the various locations for directing outgoing light beams containing the same information as their cooperating displays from these locations to the central location. Each of these outgoing beams is applied to a detection arrangement, e.g., a fluorescence spectroscope, for retrieving the information contained thereby.

Remote multi-position information gathering system and method

DOEpatents

Hirschfeld, Tomas B.

1986-01-01

A technique for gathering specific information from various remote locations, especially fluorimetric information characteristic of particular materials at the various locations is disclosed herein. This technique uses a single source of light disposed at still a different, central location and an overall optical network including an arrangement of optical fibers cooperating with the light source for directing individual light beams into the different information bearing locations. The incoming light beams result in corresponding displays of light, e.g., fluorescent light, containing the information to be obtained. The optical network cooperates with these light displays at the various locations for directing ongoing light beams containing the same information as their cooperating displays from these locations to the central location. Each of these outgoing beams is applied to a detection arrangement, e.g., a fluorescence spectroscope, for retrieving the information contained thereby.

Remote multi-position information gathering system and method

DOEpatents

Hirschfeld, T.B.

1989-01-24

A technique for gathering specific information from various remote locations, especially fluorimetric information characteristic of particular materials at the various locations is disclosed herein. This technique uses a single source of light disposed at still a different, central location and an overall optical network including an arrangement of optical fibers cooperating with the light source for directing individual light beams into the different information bearing locations. The incoming light beams result in corresponding displays of light, e.g., fluorescent light, containing the information to be obtained. The optical network cooperates with these light displays at the various locations for directing outgoing light beams containing the same information as their cooperating displays from these locations to the central location. Each of these outgoing beams is applied to a detection arrangement, e.g., a fluorescence spectroscope, for retrieving the information contained thereby. 9 figs.

Remote multi-position information gathering system and method

DOEpatents

Hirschfeld, T.B.

1986-12-02

A technique for gathering specific information from various remote locations, especially fluorimetric information characteristic of particular materials at the various locations is disclosed herein. This technique uses a single source of light disposed at still a different, central location and an overall optical network including an arrangement of optical fibers cooperating with the light source for directing individual light beams into the different information bearing locations. The incoming light beams result in corresponding displays of light, e.g., fluorescent light, containing the information to be obtained. The optical network cooperates with these light displays at the various locations for directing outgoing light beams containing the same information as their cooperating displays from these locations to the central location. Each of these outgoing beams is applied to a detection arrangement, e.g., a fluorescence spectroscope, for retrieving the information contained thereby. 9 figs.

Remote multi-position information gathering system and method

DOEpatents

Hirschfeld, Tomas B.

1989-01-01

A technique for gathering specific information from various remote locations, especially fluorimetric information characteristic of particular materials at the various locations is disclosed herein. This technique uses a single source of light disposed at still a different, central location and an overall optical network including an arrangement of optical fibers cooperating with the light source for directing individual light beams into the different information bearing locations. The incoming light beams result in corresponding displays of light, e.g., fluorescent light, containing the information to be obtained. The optical network cooperates with these light displays at the various locations for directing outgoing light beams containing the same information as their cooperating displays from these locations to the central location. Each of these outgoing beams is applied to a detection arrangement, e.g., a fluorescence spectroscope, for retrieving the information contained thereby.

Electron-beam lithography for micro and nano-optical applications

NASA Technical Reports Server (NTRS)

Wilson, Daniel W.; Muller, Richard E.; Echternach, Pierre M.

2005-01-01

Direct-write electron-beam lithography has proven to be a powerful technique for fabricating a variety of micro- and nano-optical devices. Binary E-beam lithography is the workhorse technique for fabricating optical devices that require complicated precision nano-scale features. We describe a bi-layer resist system and virtual-mark height measurement for improving the reliability of fabricating binary patterns. Analog E-beam lithography is a newer technique that has found significant application in the fabrication of diffractive optical elements. We describe our techniques for fabricating analog surface-relief profiles in E-beam resist, including some discussion regarding overcoming the problems of resist heating and charging. We also describe a multiple-field-size exposure scheme for suppression of field-stitch induced ghost diffraction orders produced by blazed diffraction gratings on non-flat substrates.

Wind Tunnel Force Balance Calibration Study - Interim Results

NASA Technical Reports Server (NTRS)

Rhew, Ray D.

2012-01-01

Wind tunnel force balance calibration is preformed utilizing a variety of different methods and does not have a direct traceable standard such as standards used for most calibration practices (weights, and voltmeters). These different calibration methods and practices include, but are not limited to, the loading schedule, the load application hardware, manual and automatic systems, re-leveling and non-re-leveling. A study of the balance calibration techniques used by NASA was undertaken to develop metrics for reviewing and comparing results using sample calibrations. The study also includes balances of different designs, single and multi-piece. The calibration systems include, the manual, and the automatic that are provided by NASA and its vendors. The results to date will be presented along with the techniques for comparing the results. In addition, future planned calibrations and investigations based on the results will be provided.

Direct analysis in real time--high resolution mass spectrometry as a valuable tool for the pharmaceutical drug development.

PubMed

Srbek, Jan; Klejdus, Bořivoj; Douša, Michal; Břicháč, Jiří; Stasiak, Pawel; Reitmajer, Josef; Nováková, Lucie

2014-12-01

In this study, direct analysis in real time-mass spectrometry (DART-MS) was assessed for the analysis of various pharmaceutical formulations with intention to summarize possible applications for the routine pharmaceutical development. As DART is an ambient ionization technique, it allows direct analysis of pharmaceutical samples in solid or liquid form without complex sample preparation, which is often the most time-consuming part of the analytical method. This makes the technique suitable for many application fields, including pharmaceutical drug development. DART mass spectra of more than twenty selected tablets and other common pharmaceutical formulations, i.e. injection solutions, ointments and suppositories developed in the pharmaceutical industry during several recent years are presented. Moreover, as thin-layer chromatography (TLC) is still very popular for the monitoring of the reactions in the synthetic chemistry, several substances were analyzed directly from the TLC plates to demonstrate the simplicity of the technique. Pure substance solutions were spotted onto a TLC plate and then analyzed with DART without separation. This was the first DART-MS study of pharmaceutical dosage forms using DART-Orbitrap combination. The duration of sample analysis by the DART-MS technique lasted several seconds, allowing enough time to collect sufficient number of data points for compound identification. The experimental setup provided excellent mass accuracy and high resolution of the mass spectra which allowed unambiguous identification of the compounds of interest. Finally, DART mass spectrometry was also used for the monitoring of the selected impurity distribution in the atorvastatin tablets. These measurements demonstrated DART to be robust ionization technique, which provided easy-to-interpret mass spectra for the broad range of compounds. DART has high-throughput potential for various types of pharmaceutical analyses and therefore eliminates the time for sample cleanup and chromatographic separation. Copyright © 2014 Elsevier B.V. All rights reserved.

Direct shear mapping - a new weak lensing tool

NASA Astrophysics Data System (ADS)

de Burgh-Day, C. O.; Taylor, E. N.; Webster, R. L.; Hopkins, A. M.

2015-08-01

We have developed a new technique called direct shear mapping (DSM) to measure gravitational lensing shear directly from observations of a single background source. The technique assumes the velocity map of an unlensed, stably rotating galaxy will be rotationally symmetric. Lensing distorts the velocity map making it asymmetric. The degree of lensing can be inferred by determining the transformation required to restore axisymmetry. This technique is in contrast to traditional weak lensing methods, which require averaging an ensemble of background galaxy ellipticity measurements, to obtain a single shear measurement. We have tested the efficacy of our fitting algorithm with a suite of systematic tests on simulated data. We demonstrate that we are in principle able to measure shears as small as 0.01. In practice, we have fitted for the shear in very low redshift (and hence unlensed) velocity maps, and have obtained null result with an error of ±0.01. This high-sensitivity results from analysing spatially resolved spectroscopic images (i.e. 3D data cubes), including not just shape information (as in traditional weak lensing measurements) but velocity information as well. Spirals and rotating ellipticals are ideal targets for this new technique. Data from any large Integral Field Unit (IFU) or radio telescope is suitable, or indeed any instrument with spatially resolved spectroscopy such as the Sydney-Australian-Astronomical Observatory Multi-Object Integral Field Spectrograph (SAMI), the Atacama Large Millimeter/submillimeter Array (ALMA), the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) and the Square Kilometer Array (SKA).

A comparison between DART-MS and DSA-MS in the forensic analysis of writing inks.

PubMed

Drury, Nicholas; Ramotowski, Robert; Moini, Mehdi

2018-05-23

Ambient ionization mass spectrometry is gaining momentum in forensic science laboratories because of its high speed of analysis, minimal sample preparation, and information-rich results. One such application of ambient ionization methodology includes the analysis of writing inks from questioned documents where colorants of interest may not be soluble in common solvents, rendering thin layer chromatography (TLC) and separation-mass spectrometry methods such as LC/MS (-MS) impractical. Ambient ionization mass spectrometry uses a variety of ionization techniques such as penning ionization in Direct Analysis in Real Time (DART), and atmospheric pressure chemical ionization in Direct Sample Analysis (DSA), and electrospray ionization in Desorption Electrospray Ionization (DESI). In this manuscript, two of the commonly used ambient ionization techniques are compared: Perkin Elmer DSA-MS and IonSense DART in conjunction with a JEOL AccuTOF MS. Both technologies were equally successful in analyzing writing inks and produced similar spectra. DSA-MS produced less background signal likely because of its closed source configuration; however, the open source configuration of DART-MS provided more flexibility for sample positioning for optimum sensitivity and thereby allowing smaller piece of paper containing writing ink to be analyzed. Under these conditions, the minimum sample required for DART-MS was 1mm strokes of ink on paper, whereas DSA-MS required a minimum of 3mm. Moreover, both techniques showed comparable repeatability. Evaluation of the analytical figures of merit, including sensitivity, linear dynamic range, and repeatability, for DSA-MS and DART-MS analysis is provided. To the forensic context of the technique, DART-MS was applied to the analysis of United States Secret Service ink samples directly on a sampling mesh, and the results were compared with DSA-MS of the same inks on paper. Unlike analysis using separation mass spectrometry, which requires sample preparation, both DART-MS and DSA-MS successfully analyzed writing inks with minimal sample preparation. Copyright © 2018 Elsevier B.V. All rights reserved.

Electrolyzer assembly method and system

DOEpatents

Swala, Dana Ray; Bourgeois, Richard Scott; Paraszczak, Steven; Buckley, Donald Joseph

2017-05-23

The present techniques provide a novel electrolyzer and methods for welding components of such electrolyzers. The techniques may use conductors, such as resistance wires, placed in paths around the internal structural features and edges of the components. The conductors may be incorporated into the components during manufacture by injection molding, or other molding techniques, or may be tacked or otherwise applied to the surface of the components after manufacture. When current, a field or other excitation is applied to the conductors, the plastic surrounding the wire is melted. If this plastic is in direct contact with an adjoining component, a strong, hermetic seal may be formed between the two components, including the internal structural features.

[Methods of brain stimulation based on weak electric current--future tool for the clinician?].

PubMed

Kotilainen, Tuukka; Lehto, Soili M

2016-01-01

Methods of brain stimulation based on a weak electric current are non-invasive neuromodulation techniques. They include transcranial direct current, alternating current and random noise stimulation. These methods modify the membrane potential of neurons without triggering the action potential, and have been successfully utilized to influence cognition and regulation of emotions in healthy experimental subjects. In clinical studies, indications of the efficacy of these techniques have been obtained in the treatment of depression, schizophrenia, memory disorders and pain as well as in stroke rehabilitation. It is hoped that these techniques will become established as part of the care and rehabilitation of psychiatric and neurologic patients in the future.

High resolution spectroscopy in the microwave and far infrared

NASA Technical Reports Server (NTRS)

Pickett, Herbert M.

1990-01-01

High resolution rotational spectroscopy has long been central to remote sensing techniques in atmospheric sciences and astronomy. As such, laboratory measurements must supply the required data to make direct interpretation of data for instruments which sense atmospheres using rotational spectra. Spectral measurements in the microwave and far infrared regions are also very powerful tools when combined with infrared measurements for characterizing the rotational structure of vibrational spectra. In the past decade new techniques were developed which have pushed high resolution spectroscopy into the wavelength region between 25 micrometers and 2 mm. Techniques to be described include: (1) harmonic generation of microwave sources, (2) infrared laser difference frequency generation, (3) laser sideband generation, and (4) ultrahigh resolution interferometers.

The fate of neurotization techniques on reinnervation after denervation of the gastrocnemius muscle: an experimental study.

PubMed

Askar, I; Sabuncuoglu, B T; Yormuk, E; Saray, A

2001-07-01

In nerve injuries, if it is not possible to reinnervate muscle by using neurorrhaphy and nerve grafting technique, reinnervation should be provided by the use of neuroization-directly implanting motor nerve into muscle. A comparative study of three techniques of neurotization is presented in rabbits. In this experimental study, a total of 40 white New Zealand rabbits were used and divided into four groups, each including 10 rabbits. In the first group (control--Group 1), only surgical exposure of the gastrocnemius muscle, main muscle nerve (tibial nerve), and peroneal nerve was done, without any injury to the nerves. In the second group (direct neurotization group--Group 2), the tibial nerve was transected, and the peroneal nerve, which had already been divided into fascicles, was implanted into the lateral head of the gastrocnemius muscle aneural zone. In the third group (dual neurotization group--Group 3), the tibial nerve which had been transected and re-anastomosed, and the peroneal nerve were implanted into the lateral head of the gastrocnemius muscle. In the last experimental group (hyperneurotization group--Group 4), fascicles of the peroneal nerve were implanted into the lateral head of the gastrocnemius, preserving the tibial nerve. Six months later, changes in the histologic pattern and the functional recovery of the gastrocnemius muscle were investigated. It was found that functional recovery was achieved in all neurotization groups. Groups with the tibial nerve transected had less muscular weights than those of groups with the tibial nerve intact. EMG recordings showed that polyphasic and late potentials were frequently seen in groups with the tibial nerve transected. Degeneration and regeneration of myofibrils was observed in such groups as well. New motor end-plates, including vesicles, were formed in a scattered manner in all neurotization groups. As a result, the authors conclude that direct and dual neurotization techniques are useful in peripheral nerve injuries, if it is not possible to reinnervate muscle by using neurorraphy and nerve grafting, and that there is no suggested superiority among these techniques.

Method and apparatus for ion mobility spectrometry with alignment of dipole direction (IMS-ADD)

DOEpatents

Shvartsburg, Alexandre A [Richland, WA; Tang, Keqi [Richland, WA; Smith, Richard D [Richland, WA

2007-01-30

Techniques and instrumentation are described for analyses of substances, including complex samples/mixtures that require separation prior to characterization of individual components. A method is disclosed for separation of ion mixtures and identification of ions, including protein and other macromolecular ions and their different structural isomers. Analyte ions are not free to rotate during the separation, but are substantially oriented with respect to the drift direction. Alignment is achieved by applying, at a particular angle to the drift field, a much stronger alternating electric field that "locks" the ion dipoles with moments exceeding a certain value. That value depends on the buffer gas composition, pressure, and temperature, but may be as low as .about.3 Debye under certain conditions. The presently disclosed method measures the direction-specific cross-sections that provide the structural information complementing that obtained from known methods, and, when coupled to those methods, increases the total peak capacity and specificity of gas-phase separations. Simultaneous 2-D separations by direction-specific cross sections along and orthogonally to the ion dipole direction are also possible.

Directed assembly of hybrid nanostructures using optically resonant nanotweezers

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

Erickson, David

This represents the final report for this project. Over the course of the project we have made significant progress in photonically driven nano-assembly including: (1) demonstrating the first direct optical tweezer based manipulation of proteins, (2) the ability to apply optical angular torques to microtubuals and other rod-shaped microparticles, (3) direct assembly of hybrid nanostructures comprising of polymeric nanoparticles and carbon nanotubes and, (4) the ability to drive biological reactions (specifically protein aggregation) that are thermodynamically unfavorable by applying localized optical work. These advancements are described in the list of papers provided in section 2.0 of the below. Summary detailsmore » are provided in prior year annual reports. We have two additional papers which will be submitted shortly based on the work done under this award. An updated publication list will be provided to the program manager when those are accepted. In this report, we report on a new advancement made in the final project year, which uses the nanotweezer technology to perform direct measurements of particle-surface interactions. Briefly, these measurements are important for characterizing the stability and behavior of colloidal and nanoparticle suspensions and current techniques are limited in their ability to measure piconewton scale interaction forces on sub-micrometer particles due to signal detection limits and thermal noise. In this project year we developed a new technique called “Nanophotonic Force Microscopy” which uses the localized region of exponentially decaying, near-field, light to confine small particles close to a surface. From the statistical distribution of the light intensity scattered by the particle the technique maps out the potential well of the trap and directly quantify the repulsive force between the nanoparticle and the surface. The major advantage of the technique is that it can measure forces and energy wells below the thermal noise limit, resolving interaction forces smaller than 1 pN on dielectric particles as small as 100 nm in diameter.« less

Autonomous space target recognition and tracking approach using star sensors based on a Kalman filter.

PubMed

Ye, Tao; Zhou, Fuqiang

2015-04-10

When imaged by detectors, space targets (including satellites and debris) and background stars have similar point-spread functions, and both objects appear to change as detectors track targets. Therefore, traditional tracking methods cannot separate targets from stars and cannot directly recognize targets in 2D images. Consequently, we propose an autonomous space target recognition and tracking approach using a star sensor technique and a Kalman filter (KF). A two-step method for subpixel-scale detection of star objects (including stars and targets) is developed, and the combination of the star sensor technique and a KF is used to track targets. The experimental results show that the proposed method is adequate for autonomously recognizing and tracking space targets.

PADF RF localization experiments with multi-agent caged-MAV platforms

NASA Astrophysics Data System (ADS)

Barber, Christopher; Gates, Miguel; Selmic, Rastko; Al-Issa, Huthaifa; Ordonez, Raul; Mitra, Atindra

2011-06-01

This paper provides a summary of preliminary RF direction finding results generated within an AFOSR funded testbed facility recently developed at Louisiana Tech University. This facility, denoted as the Louisiana Tech University Micro- Aerial Vehicle/Wireless Sensor Network (MAVSeN) Laboratory, has recently acquired a number of state-of-the-art MAV platforms that enable us to analyze, design, and test some of our recent results in the area of multiplatform position-adaptive direction finding (PADF) [1] [2] for localization of RF emitters in challenging embedded multipath environments. Discussions within the segmented sections of this paper include a description of the MAVSeN Laboratory and the preliminary results from the implementation of mobile platforms with the PADF algorithm. This novel approach to multi-platform RF direction finding is based on the investigation of iterative path-loss based (i.e. path loss exponent) metrics estimates that are measured across multiple platforms in order to develop a control law that robotically/intelligently positionally adapt (i.e. self-adjust) the location of each distributed/cooperative platform. The body of this paper provides a summary of our recent results on PADF and includes a discussion on state-of-the-art Sensor Mote Technologies as applied towards the development of sensor-integrated caged-MAV platform for PADF applications. Also, a discussion of recent experimental results that incorporate sample approaches to real-time singleplatform data pruning is included as part of a discussion on potential approaches to refining a basic PADF technique in order to integrate and perform distributed self-sensitivity and self-consistency analysis as part of a PADF technique with distributed robotic/intelligent features. These techniques are extracted in analytical form from a parallel study denoted as "PADF RF Localization Criteria for Multi-Model Scattering Environments". The focus here is on developing and reporting specific approaches to self-sensitivity and self-consistency within this experimental PADF framework via the exploitation of specific single-agent caged-MAV trajectories that are unique to this experiment set.

A high voltage dielectrically isolated smart power technology based on silicon direct bonding

NASA Astrophysics Data System (ADS)

Macary, Veronique

1992-09-01

The feasibility of a dielectrically isolated technology based on the silicon direct bonding technique, for high voltage smart power applications in the 1000 to 1550 V/1 to 20 A range, where a vertical power switch is necessary, is investigated and demonstrated. Static and dynamic isolation of the low voltage circuitry integrated beside the vertical power transistor is the main concern of this family of circuits. The dielectric isolation offers better protection to the low voltage part than does the junction isolation, because of the elimination of the parasitic bipolar transistor inherent to the latter isolation technique. Silicon direct bonding provides a cost effective way to obtain a buried oxide isolation layer. In addition, the application requires a Si/Si bonded area in the active region of the vertical power switch. Strong influence of the prebonding cleaning in the electrical characteristics of the Si/Si interface is pointed out, and presence of crystalline defects is assumed to be at the origin of electrical failures. The main problems of silicon direct bonding process compatibility with standard processes were overcome, and a complete process flow, including the simultaneous integration of a vertical power bipolar transistor together with a bipolar control circuitry, was validated. Using a peripheral biased ring is shown to provide an easy way to optimize high voltage termination for the smart power circuit, while adding a non-additional technological step. This technique was studied by dimensional electrical simulations (BIDIM2 software), as well as analytically computed.

Probing of Metabolites in Finely Powdered Plant Material by Direct Laser Desorption Ionization Mass Spectrometry

NASA Astrophysics Data System (ADS)

Musharraf, Syed Ghulam; Ali, Arslan; Choudhary, M. Iqbal; Atta-ur-Rahman

2014-04-01

Natural products continue to serve as an important source of novel drugs since the beginning of human history. High-throughput techniques, such as MALDI-MS, can be techniques of choice for the rapid screening of natural products in plant materials. We present here a fast and reproducible matrix-free approach for the direct detection of UV active metabolites in plant materials without any prior sample preparation. The plant material is mechanically ground to a fine powder and then sieved through different mesh sizes. The collected plant material is dispersed using 1 μL solvent on a target plate is directly exposed to Nd:YAG 335 nm laser. The strategy was optimized for the analysis of plant metabolites after study of the different factors affecting the reproducibility and effectiveness of the analysis, including particle sizes effects, types of solvents used to disperse the sample, and the part of the plant analyzed. Moreover, several plant species, known for different classes of metabolites, were screened to establish the generality of the approach. The developed approach was validated by the characterization of withaferin A and nicotine in the leaves of Withania somnifera and Nicotiana tabacum, respectively, through comparison of its MS/MS data with the standard compound. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques were used for the tissue imaging purposes. This approach can be used to directly probe small molecules in plant materials as well as in herbal and pharmaceutical formulations for fingerprinting development.

Radioresistance of GGG Sequences to Prompt Strand Break Formation from Direct-Type Radiation Damage

PubMed Central

Black, Paul J.; Miller, Adam S.; Hayes, Jeffrey J.

2016-01-01

Purpose As humans, we are constantly exposed to ionizing radiation from natural, man-made and cosmic sources which can damage DNA, leading to deleterious effects including cancer incidence. In this work we introduce a method to monitor strand breaks resulting from damage due to the direct effect of ionizing radiation and provide evidence for sequence-dependent effects leading to strand breaks. Materials and methods To analyze only DNA strand breaks caused by radiation damage due to the direct effect of ionizing radiation, we combined an established technique to generate dehydrated DNA samples with a technique to analyze single strand breaks on short oligonucleotide sequences via denaturing gel electrophoresis. Results We find that direct damage primarily results in a reduced number of strand breaks in guanine triplet regions (GGG) when compared to isolated guanine (G) bases with identical flanking base context. In addition, we observe strand break behavior possibly indicative of protection of guanine bases when flanked by pyrimidines, and sensitization of guanine to strand break when flanked by adenine (A) bases in both isolated G and GGG cases. Conclusions These observations provide insight into the strand break behavior in GGG regions damaged via the direct effect of ionizing radiation. In addition, this could be indicative of DNA sequences that are naturally more susceptible to strand break due to the direct effect of ionizing radiation. PMID:27349757

Parabolic aircraft solidification experiments

NASA Technical Reports Server (NTRS)

Workman, Gary L. (Principal Investigator); Smith, Guy A.; OBrien, Susan

1996-01-01

A number of solidification experiments have been utilized throughout the Materials Processing in Space Program to provide an experimental environment which minimizes variables in solidification experiments. Two techniques of interest are directional solidification and isothermal casting. Because of the wide-spread use of these experimental techniques in space-based research, several MSAD experiments have been manifested for space flight. In addition to the microstructural analysis for interpretation of the experimental results from previous work with parabolic flights, it has become apparent that a better understanding of the phenomena occurring during solidification can be better understood if direct visualization of the solidification interface were possible. Our university has performed in several experimental studies such as this in recent years. The most recent was in visualizing the effect of convective flow phenomena on the KC-135 and prior to that were several successive contracts to perform directional solidification and isothermal casting experiments on the KC-135. Included in this work was the modification and utilization of the Convective Flow Analyzer (CFA), the Aircraft Isothermal Casting Furnace (ICF), and the Three-Zone Directional Solidification Furnace. These studies have contributed heavily to the mission of the Microgravity Science and Applications' Materials Science Program.

Rapid and direct screening of H:C ratio in Archean kerogen via microRaman Spectroscopy

NASA Astrophysics Data System (ADS)

Ferralis, N.; Matys, E. D.; Allwood, A.; Knoll, A. H.; Summons, R. E.

2015-12-01

Rapid evaluation of the preservation of biosignatures in ancient kerogens is essential for the evaluation of the usability of Earth analogues as proxies of Martian geological materials. No single, non-destructive and non-invasive technique currently exists to rapidly determine such state of preservation of the organic matter in relation to its geological and mineral environment. Due to its non-invasive nature, microRaman spectroscopy is emerging as a candidate technique for the qualitative determination maturity of organic matter, by correlating Raman spectral features and aromatic carbon cluster size. Here we will present a novel quantitative method in which before-neglected Raman spectral features are correlated directly and with excellent accuracy with the H:C ratio. In addition to providing a chemical justification of the found direct correlation, we will show its applicability and predictive capabilities in evaluating H:C in Archean kerogens. This novel method opens new opportunities for the use of Raman spectroscopy and mapping. This includes the non-invasively determination of kerogen preservation and microscale chemical diversity within a particular Earth analogue, to be potentially extended to evaluate Raman spectra acquired directly on Mars.

Reductionist Approach in Peptide-Based Nanotechnology.

PubMed

Gazit, Ehud

2018-06-20

The formation of ordered nanostructures by molecular self-assembly of proteins and peptides represents one of the principal directions in nanotechnology. Indeed, polyamides provide superior features as materials with diverse physical properties. A reductionist approach allowed the identification of extremely short peptide sequences, as short as dipeptides, which could form well-ordered amyloid-like β-sheet-rich assemblies comparable to supramolecular structures made of much larger proteins. Some of the peptide assemblies show remarkable mechanical, optical, and electrical characteristics. Another direction of reductionism utilized a natural noncoded amino acid, α-aminoisobutryic acid, to form short superhelical assemblies. The use of this exceptional helix inducer motif allowed the fabrication of single heptad repeats used in various biointerfaces, including their use as surfactants and DNA-binding agents. Two additional directions of the reductionist approach include the use of peptide nucleic acids (PNAs) and coassembly techniques. The diversified accomplishments of the reductionist approach, as well as the exciting future advances it bears, are discussed.

Front lighted optical tooling method and apparatus

DOEpatents

Stone, W.J.

1983-06-30

An optical tooling method and apparatus uses a front lighted shadowgraphic technique to enhance visual contrast of reflected light. The apparatus includes an optical assembly including a fiducial mark, such as cross hairs, reflecting polarized light with a first polarization, a polarizing element backing the fiducial mark and a reflective surface backing the polarizing element for reflecting polarized light bypassing the fiducial mark and traveling through the polarizing element. The light reflected by the reflecting surface is directed through a second pass of the polarizing element toward the frontal direction with a polarization differing from the polarization of the light reflected by the fiducial mark. When used as a tooling target, the optical assembly may be mounted directly to a reference surface or may be secured in a mounting, such as a magnetic mounting. The optical assembly may also be mounted in a plane defining structure and used as a spherometer in conjunction with an optical depth measuring instrument.

Thermoelectric properties of n-type polycrystalline BixSb2-xTe3 alloys

NASA Technical Reports Server (NTRS)

Snyder, J.; Gerovac, N.; Caillat, T.

2002-01-01

(BixSbl-x)2Te3(.5 = x = .7) polycrystalline samples were synthesized using a combination of melting and powder metallurgy techniques. The samples were hot pressed in graphite dies and cut perpendicular and parallel to the pressing direction. Samples were examined by microprobe analysis to determine their atomic composition. The thermoelectric properties were measured at room temperature in both directions. These properties include Seebeck coefficient, thermal conductivity, electrical resistivity, and Hall effect. The thermoelectric figure-of-merit, ZT, was calculated fiom these properties.

Four modes of optical parametric operation for squeezed state generation

NASA Astrophysics Data System (ADS)

Andersen, U. L.; Buchler, B. C.; Lam, P. K.; Wu, J. W.; Gao, J. R.; Bachor, H.-A.

2003-11-01

We report a versatile instrument, based on a monolithic optical parametric amplifier, which reliably generates four different types of squeezed light. We obtained vacuum squeezing, low power amplitude squeezing, phase squeezing and bright amplitude squeezing. We show a complete analysis of this light, including a full quantum state tomography. In addition we demonstrate the direct detection of the squeezed state statistics without the aid of a spectrum analyser. This technique makes the nonclassical properties directly visible and allows complete measurement of the statistical moments of the squeezed quadrature.

Effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts.

PubMed

Ebadian, Behnaz; Rismanchian, Mansor; Dastgheib, Badrosadat; Bajoghli, Farshad

2015-01-01

Different factors such as impression techniques and materials can affect the passive fit between the superstructure and implant. The aim of this study was to determine the effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts. Four internal hex implants (Biohorizons Ø4 mm) were placed on a metal maxillary model perpendicular to the horizontal plane in maxillary lateral incisors, right canine and left first premolar areas. Three impression techniques including open tray, closed tray using ball top screw abutments and closed tray using short impression copings and two impression materials (polyether and polyvinyl siloxane) were evaluated (n = 60). The changes in distances between implant analogues in mediolateral (x) and anteroposterior (y) directions and analogue angles in x/z and y/z directions in the horizontal plane on the definitive casts were measured by coordinate measuring machine. The data were analyzed by multivariate two-way analysis of variance and one sample t-test (α = 0.05). No statistical significant differences were observed between different impression techniques and materials. However, deviation and distortion of definitive casts had a significant difference with the master model when short impression copings and polyvinyl siloxane impression material were used (P < 0.05). In open tray technique, there was a significant difference in the rotation of analogs compared with the master model with both impression materials (P < 0.05). There was no difference between open and closed tray impression techniques; however, less distortion and deviation were observed in the open tray technique. In the closed tray impression technique, ball top screw was more accurate than short impression copings.

Effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts

PubMed Central

Ebadian, Behnaz; Rismanchian, Mansor; Dastgheib, Badrosadat; Bajoghli, Farshad

2015-01-01

Background: Different factors such as impression techniques and materials can affect the passive fit between the superstructure and implant. The aim of this study was to determine the effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts. Materials and Methods: Four internal hex implants (Biohorizons Ø4 mm) were placed on a metal maxillary model perpendicular to the horizontal plane in maxillary lateral incisors, right canine and left first premolar areas. Three impression techniques including open tray, closed tray using ball top screw abutments and closed tray using short impression copings and two impression materials (polyether and polyvinyl siloxane) were evaluated (n = 60). The changes in distances between implant analogues in mediolateral (x) and anteroposterior (y) directions and analogue angles in x/z and y/z directions in the horizontal plane on the definitive casts were measured by coordinate measuring machine. The data were analyzed by multivariate two-way analysis of variance and one sample t-test (α = 0.05). Results: No statistical significant differences were observed between different impression techniques and materials. However, deviation and distortion of definitive casts had a significant difference with the master model when short impression copings and polyvinyl siloxane impression material were used (P < 0.05). In open tray technique, there was a significant difference in the rotation of analogs compared with the master model with both impression materials (P < 0.05). Conclusion: There was no difference between open and closed tray impression techniques; however, less distortion and deviation were observed in the open tray technique. In the closed tray impression technique, ball top screw was more accurate than short impression copings. PMID:25878678

Tendon 'turnover lengthening' technique.

PubMed

Cerovac, S; Miranda, B H

2013-11-01

Tendon defect reconstruction is amongst the most technically challenging areas in hand surgery. Tendon substance deficiency reconstruction techniques include lengthening, grafting, two-stage reconstruction and tendon transfers, however each is associated with unique challenges over and above direct repair. We describe a novel 'turnover lengthening' technique for hand tendons that has successfully been applied to the repair of several cases, including a case of attritional flexor and traumatic extensor tendon rupture in two presented patients where primary tenorrhaphy was not possible. In both cases a good post-operative outcome was achieved, as the patients were happy having returned back to normal activities of daily living such that they were discharged 12 weeks post-operatively. Our technique avoids the additional morbidity and complications associated with grafting, transfers and two stage reconstructions. It is quick, simple and reproducible for defects not exceeding 3-4 cm, provides a means of immediate one stage reconstruction, no secondary donor site morbidity and does not compromise salvage by tendon transfer and/or two-stage reconstruction in cases of failure. To our knowledge no such technique has been previously been described to reconstruct such hand tendon defects. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Directed network modules

NASA Astrophysics Data System (ADS)

Palla, Gergely; Farkas, Illés J.; Pollner, Péter; Derényi, Imre; Vicsek, Tamás

2007-06-01

A search technique locating network modules, i.e. internally densely connected groups of nodes in directed networks is introduced by extending the clique percolation method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos-Rényi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own web-pages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae. The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and Google's web-pages, overlaps are likely to contain in-hubs, whereas the modules in the email and transcriptional regulatory network tend to overlap via out-hubs.

Direct diode lasers with comparable beam quality to fiber, CO2, and solid state lasers

NASA Astrophysics Data System (ADS)

Huang, Robin K.; Chann, Bien; Burgess, James; Kaiman, Michael; Overman, Robert; Glenn, John D.; Tayebati, Parviz

2012-03-01

TeraDiode has produced kW-class ultra-high brightness fiber-coupled direct diode lasers. A fiber-coupled direct diode laser with a power level of 2,040 W from a 50 μm core diameter, 0.15 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. This was achieved with a novel beam combining and shaping technique using COTS diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.75 mm-mrad and is the lowest BPP kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 2-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers.

The sensitivity of direct faecal examination, direct faecal flotation, modified centrifugal faecal flotation and centrifugal sedimentation/flotation in the diagnosis of canine spirocercosis.

PubMed

Christie, J; Schwan, E V; Bodenstein, L L; Sommerville, J E M; van der Merwe, L L

2011-06-01

Several faecal examination techniques have shown variable sensitivity in demonstrating Spirocerca lupi (S. lupi) eggs. The objective of this study was to determine which faecal examination technique, including a novel modified centrifugal flotation technique, was most sensitive to diagnose spirocercosis. Ten coproscopic examinations were performed on faeces collected from 33 dogs confirmed endoscopically to have spirocercosis. The tests included a direct faecal examination, a faecal sedimentation/flotation test, 4 direct faecal flotations and 4 modified faecal centrifugal flotations. These latter 2 flotation tests utilised 4 different faecal flotation solutions: NaNO3 (SG 1.22), MgSO4 (SG 1.29), ZnSO4 (SG 1.30) and sugar (SG 1.27). The sensitivity of the tests ranged between 42% and 67%, with the NaNO3 solution showing the highest sensitivity in both the direct and modified-centrifugal flotations. The modified NaNO3 centrifugal method ranked 1st with the highest mean egg count (45.24 +/- 83), and was superior (i.e. higher egg count) and significantly different (P < 0.05) compared with the routine saturated sugar, ZnSO4 and MgSO4 flotation methods. The routine NaNO3 flotation method was also superior and significantly different (P < 0.05) compared with the routine ZnSO4 and MgSO4 flotation methods. Fifteen per cent (n = 5) of dogs had neoplastic oesophageal nodules and a further 18% (n = 6) had both neoplastic and non-neoplastic nodules. S. lupi eggs were demonstrated in 40% of dogs with neoplastic nodules only and 72.9% of the dogs with non-neoplastic nodules. The mean egg count in the non-neoplastic group (61) was statistically greater (P = 0.02) than that of the neoplastic group (1). The results show that faecal examination using a NaNO3 solution is the most sensitive in the diagnosis of spirocercosis. The modified centrifugal flotation faecal method using this solution has the highest egg count. The study also found that dogs with neoplastic nodules shed significantly fewer eggs than dogs with non-neoplastic nodules.

ASRDI oxygen technology survey. Volume 5: Density and liquid level measurement instrumentation for the cryogenic fluids oxygen, hydrogen, and nitrogen

NASA Technical Reports Server (NTRS)

Roder, H. M.

1974-01-01

Information is presented on instrumentation for density measurement, liquid level measurement, quantity gauging, and phase measurement. Coverage of existing information directly concerned with oxygen was given primary emphasis. A description of the physical principle of measurement for each instrumentation type is included. The basic materials of construction are listed if available from the source document for each instrument discussed. Cleaning requirements, procedures, and verification techniques are included.

Effects of implant system, impression technique, and impression material on accuracy of the working cast.

PubMed

Wegner, Kerstin; Weskott, Katharina; Zenginel, Martha; Rehmann, Peter; Wöstmann, Bernd

2013-01-01

This in vitro study aimed to identify the effects of the implant system, impression technique, and impression material on the transfer accuracy of implant impressions. The null hypothesis tested was that, in vitro and within the parameters of the experiment, the spatial relationship of a working cast to the placement of implants is not related to (1) the implant system, (2) the impression technique, or (3) the impression material. A steel maxilla was used as a reference model. Six implants of two different implant systems (Standard Plus, Straumann; Semados, Bego) were fixed in the reference model. The target variables were: three-dimensional (3D) shift in all directions, implant axis direction, and rotation. The target variables were assessed using a 3D coordinate measuring machine, and the respective deviations of the plaster models from the nominal values of the reference model were calculated. Two different impression techniques (reposition/pickup) and four impression materials (Aquasil Ultra, Flexitime, Impregum Penta, P2 Magnum 360) were investigated. In all, 80 implant impressions for each implant system were taken. Statistical analysis was performed using multivariate analysis of variance. The implant system significantly influenced the transfer accuracy for most spatial dimensions, including the overall 3D shift and implant axis direction. There was no significant difference between the two implant systems with regard to rotation. Multivariate analysis of variance showed a significant effect on transfer accuracy only for the implant system. Within the limits of the present study, it can be concluded that the transfer accuracy of the intraoral implant position on the working cast is far more dependent on the implant system than on the selection of a specific impression technique or material.

MEG-SIM: a web portal for testing MEG analysis methods using realistic simulated and empirical data.

PubMed

Aine, C J; Sanfratello, L; Ranken, D; Best, E; MacArthur, J A; Wallace, T; Gilliam, K; Donahue, C H; Montaño, R; Bryant, J E; Scott, A; Stephen, J M

2012-04-01

MEG and EEG measure electrophysiological activity in the brain with exquisite temporal resolution. Because of this unique strength relative to noninvasive hemodynamic-based measures (fMRI, PET), the complementary nature of hemodynamic and electrophysiological techniques is becoming more widely recognized (e.g., Human Connectome Project). However, the available analysis methods for solving the inverse problem for MEG and EEG have not been compared and standardized to the extent that they have for fMRI/PET. A number of factors, including the non-uniqueness of the solution to the inverse problem for MEG/EEG, have led to multiple analysis techniques which have not been tested on consistent datasets, making direct comparisons of techniques challenging (or impossible). Since each of the methods is known to have their own set of strengths and weaknesses, it would be beneficial to quantify them. Toward this end, we are announcing the establishment of a website containing an extensive series of realistic simulated data for testing purposes ( http://cobre.mrn.org/megsim/ ). Here, we present: 1) a brief overview of the basic types of inverse procedures; 2) the rationale and description of the testbed created; and 3) cases emphasizing functional connectivity (e.g., oscillatory activity) suitable for a wide assortment of analyses including independent component analysis (ICA), Granger Causality/Directed transfer function, and single-trial analysis.

MEG-SIM: A Web Portal for Testing MEG Analysis Methods using Realistic Simulated and Empirical Data

PubMed Central

Aine, C. J.; Sanfratello, L.; Ranken, D.; Best, E.; MacArthur, J. A.; Wallace, T.; Gilliam, K.; Donahue, C. H.; Montaño, R.; Bryant, J. E.; Scott, A.; Stephen, J. M.

2012-01-01

MEG and EEG measure electrophysiological activity in the brain with exquisite temporal resolution. Because of this unique strength relative to noninvasive hemodynamic-based measures (fMRI, PET), the complementary nature of hemodynamic and electrophysiological techniques is becoming more widely recognized (e.g., Human Connectome Project). However, the available analysis methods for solving the inverse problem for MEG and EEG have not been compared and standardized to the extent that they have for fMRI/PET. A number of factors, including the non-uniqueness of the solution to the inverse problem for MEG/EEG, have led to multiple analysis techniques which have not been tested on consistent datasets, making direct comparisons of techniques challenging (or impossible). Since each of the methods is known to have their own set of strengths and weaknesses, it would be beneficial to quantify them. Toward this end, we are announcing the establishment of a website containing an extensive series of realistic simulated data for testing purposes (http://cobre.mrn.org/megsim/). Here, we present: 1) a brief overview of the basic types of inverse procedures; 2) the rationale and description of the testbed created; and 3) cases emphasizing functional connectivity (e.g., oscillatory activity) suitable for a wide assortment of analyses including independent component analysis (ICA), Granger Causality/Directed transfer function, and single-trial analysis. PMID:22068921

Infrared Heterodyne Spectroscopy and its Unique Application to Planetary Studies

NASA Technical Reports Server (NTRS)

Kostiuk, Theodore

2009-01-01

Since the early 1970's the infrared heterodyne technique has evolved into a powerful tool for the study of molecular constituents, temperatures, and dynamics in planetary atmospheres. Its extremely high spectral resolution (Lambda/(Delta)Lambda/>10(exp 6)) and highly accurate frequency measurement (to 1 part in 10(exp 8)) enabled the detection of nonthermal/natural lasing phenomena on Mars and Venus; direct measurements of winds on Venus, Mars, and Titan; study of mid-infrared aurorae on Jupiter; direct measurement of species abundances on Mars (ozone, isotopic CO2), hydrocarbons on Jupiter, Saturn., Neptune, and Titan, and stratospheric composition in the Earth's stratosphere (O3, CIO, N2O, CO2 ....). Fully resolved emission and absorption line shapes measured by this method enabled the unambiguous retrieval of molecular abundances and local temperatures and thermal structure in regions not probed by other techniques. The mesosphere of Mars and thermosphere of Venus are uniquely probed by infrared heterodyne spectroscopy. Results of these studies tested and constrained photochemical and dynamical theoretical models describing the phenomena measured. The infrared heterodyne technique will be described. Highlights in its evolution to today's instrumentation and resultant discoveries will be presented, including work at Goddard Space Flight Center and the University of Koln. Resultant work will include studies supporting NASA and ESA space missions and collaborations between instrumental and theoretical groups.

Comparison of five parasitological techniques for laboratory diagnosis of Balantidium coli cysts.

PubMed

Barbosa, Alynne da Silva; Bastos, Otilio Machado Pereira; Uchôa, Claudia Maria Antunes; Pissinatti, Alcides; Bastos, Augusto César Machado Pereira; Souza, Igo Vieira de; Dib, Laís Verdan; Azevedo, Eduarda Peixoto; Siqueira, Mayara Perlingeiro de; Cardozo, Matheus Lessa; Amendoeira, Maria Regina Reis

2016-01-01

Balantidium coli is a protozoon that can cause dysentery in humans, pigs and nonhuman primates, with zoonotic potential. In the literature, there is still little information on the effectiveness of different laboratory techniques for diagnosing this disease. This study compared and evaluated the performance of the Lutz, modified Ritchie, Faust, modified Sheather and direct examination techniques for detecting cysts of this protozoon. Between 2012 and 2014, 1905 fecal samples were collected from captive animals in the state of Rio de Janeiro. Of these, 790 were obtained from the rectum of pigs and 1115 from enclosures occupied by nonhuman primates. B. coli cysts were most evident through direct examination (22.4% of the samples) and the Lutz technique (21%). Fair agreement (Kappa = 0.41; p < 0.05) was observed only between direct examination and Lutz. The flotation techniques (Faust and modified Sheather) did not show good recovery of cysts. A statistically significant difference (p < 0.05) in the frequency of cysts between pigs and nonhuman primates could only be observed through direct examination and the Lutz technique. The most efficient method for diagnosing this parasitosis was seen to an association between direct examination and the spontaneous sedimentation technique.

Land Surface Data Assimilation and the Northern Gulf Coast Land/Sea Breeze

NASA Technical Reports Server (NTRS)

Lapenta, William M.; Blackwell, Keith; Suggs, Ron; McNider, Richard T.; Jedlovec, Gary; Kimball, Sytske; Arnold, James E. (Technical Monitor)

2002-01-01

A technique has been developed for assimilating GOES-derived skin temperature tendencies and insolation into the surface energy budget equation of a mesoscale model so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the model's surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the modeled and satellite observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. The sea/land breeze is a well-documented mesoscale circulation that affects many coastal areas of the world including the northern Gulf Coast of the United States. The focus of this paper is to examine how the satellite assimilation technique impacts the simulation of a sea breeze circulation observed along the Mississippi/Alabama coast in the spring of 2001. The technique is implemented within the PSU/NCAR MM5 V3-4 and applied on a 4-km domain for this particular application. It is recognized that a 4-km grid spacing is too coarse to explicitly resolve the detailed, mesoscale structure of sea breezes. Nevertheless, the model can forecast certain characteristics of the observed sea breeze including a thermally direct circulation that results from differential low-level heating across the land-sea interface. Our intent is to determine the sensitivity of the circulation to the differential land surface forcing produced via the assimilation of GOES skin temperature tendencies. Results will be quantified through statistical verification techniques.

Application of Land Surface Data Assimilation to Simulations of Sea Breeze Circulations

NASA Technical Reports Server (NTRS)

Mackaro, Scott; Lapenta, William M.; Blackwell, Keith; Suggs, Ron; McNider, Richard T.; Jedlovec, Gary; Kimball, Sytske

2003-01-01

A technique has been developed for assimilating GOES-derived skin temperature tendencies and insolation into the surface energy budget equation of a mesoscale model so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the model's surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the modeled and satellite- observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. The sea/land breeze is a well-documented mesoscale circulation that affects many coastal areas of the world including the northern Gulf Coast of the United States. The focus of this paper is to examine how the satellite assimilation technique impacts the simulation of a sea breeze circulation observed along the Mississippi/Alabama coast in the spring of 2001. The technique is implemented within the PSUNCAR MM5 V3-5 and applied at spatial resolutions of 12- and 4-km. It is recognized that even 4-km grid spacing is too coarse to explicitly resolve the detailed, mesoscale structure of sea breezes. Nevertheless, the model can forecast certain characteristics of the observed sea breeze including a thermally direct circulation that results from differential low-level heating across the land-sea interface. Our intent is to determine the sensitivity of the circulation to the differential land surface forcing produced via the assimilation of GOES skin temperature tendencies. Results will be quantified through statistical verification techniques.

Applications of Low Density Flow Techniques and Catalytic Recombination at the Johnson Space Center

NASA Technical Reports Server (NTRS)

Scott, Carl D.

2000-01-01

The talk presents a brief background on defInitions of catalysis and effects associated with chemically nonequilibrium and low-density flows of aerospace interest. Applications of catalytic recombination on surfaces in dissociated flow are given, including aero heating on reentry spacecraft thermal protection surfaces and reflection of plume flow on pressure distributions associated with the space station. Examples include aero heating predictions for the X-38 test vehicle, the inlet of a proposed gas-sampling probe used in high enthalpy test facilities, and a parabolic body at angle of attack. The effect of accommodation coefficients on thruster induced pressure distributions is also included. Examples of tools used include simple aero heating formulas based on boundary layer solutions, an engineering approximation that uses axisymmetric viscous shock layer flow to simulate full three dimensional flow, full computational fluid dynamics, and direct simulation Monte-Carlo calculations. Methods of determining catalytic recombination rates in arc jet flow are discus ed. An area of catalysis not fully understood is the formation of single-wall carbon nanotubes (SWNT) with gas phase or nano-size metal particles. The Johnson Space Center is making SWNTs using both a laser ablation technique and an electric arc vaporization technique.

The effect of technique change on knee loads during sidestep cutting.

PubMed

Dempsey, Alasdair R; Lloyd, David G; Elliott, Bruce C; Steele, Julie R; Munro, Bridget J; Russo, Kylie A

2007-10-01

To identify the effect of modifying sidestep cutting technique on knee loads and predict what impact such change would have on the risk of noncontact anterior cruciate ligament injury. A force platform and motion-analysis system were used to record ground-reaction forces and track the trajectories of markers on 15 healthy males performing sidestep cutting tasks using their normal technique and nine different imposed techniques. A kinematic and inverse dynamic model was used to calculate the three-dimensional knee postures and moments. The imposed techniques of foot wide and torso leaning in the opposite direction to the cut resulted in increased peak valgus moments experienced in weight acceptance. Higher peak internal rotation moments were found for the foot wide and torso rotation in the opposite direction to the cut techniques. The foot rotated in technique resulted in lower mean flexion/extension moments, whereas the foot wide condition resulted in higher mean flexion/extension moments. The flexed knee, torso rotated in the opposite direction to the cut and torso leaning in the same direction as the cut techniques had significantly more knee flexion at heel strike. Sidestep cutting technique had a significant effect on loads experienced at the knee. The techniques that produced higher valgus and internal rotation moments at the knee, such as foot wide, torso leaning in the opposite direction to the cut and torso rotating in the opposite direction to the cut, may place an athlete at higher risk of injury because these knee loads have been shown to increase the strain on the anterior cruciate ligament. Training athletes to avoid such body positions may result in a reduced risk of noncontact anterior cruciate ligament injures.

A vector scanning processing technique for pulsed laser velocimetry

NASA Technical Reports Server (NTRS)

Wernet, Mark P.; Edwards, Robert V.

1989-01-01

Pulsed laser sheet velocimetry yields nonintrusive measurements of two-dimensional velocity vectors across an extended planar region of a flow. Current processing techniques offer high precision (1 pct) velocity estimates, but can require several hours of processing time on specialized array processors. Under some circumstances, a simple, fast, less accurate (approx. 5 pct), data reduction technique which also gives unambiguous velocity vector information is acceptable. A direct space domain processing technique was examined. The direct space domain processing technique was found to be far superior to any other techniques known, in achieving the objectives listed above. It employs a new data coding and reduction technique, where the particle time history information is used directly. Further, it has no 180 deg directional ambiguity. A complex convection vortex flow was recorded and completely processed in under 2 minutes on an 80386 based PC, producing a 2-D velocity vector map of the flow field. Hence, using this new space domain vector scanning (VS) technique, pulsed laser velocimetry data can be reduced quickly and reasonably accurately, without specialized array processing hardware.

Development of multiple source data processing for structural analysis at a regional scale. [digital remote sensing in geology

NASA Technical Reports Server (NTRS)

Carrere, Veronique

1990-01-01

Various image processing techniques developed for enhancement and extraction of linear features, of interest to the structural geologist, from digital remote sensing, geologic, and gravity data, are presented. These techniques include: (1) automatic detection of linear features and construction of rose diagrams from Landsat MSS data; (2) enhancement of principal structural directions using selective filters on Landsat MSS, Spacelab panchromatic, and HCMM NIR data; (3) directional filtering of Spacelab panchromatic data using Fast Fourier Transform; (4) detection of linear/elongated zones of high thermal gradient from thermal infrared data; and (5) extraction of strong gravimetric gradients from digitized Bouguer anomaly maps. Processing results can be compared to each other through the use of a geocoded database to evaluate the structural importance of each lineament according to its depth: superficial structures in the sedimentary cover, or deeper ones affecting the basement. These image processing techniques were successfully applied to achieve a better understanding of the transition between Provence and the Pyrenees structural blocks, in southeastern France, for an improved structural interpretation of the Mediterranean region.

Rapid detection of terbufos in stomach contents using desorption electrospray ionization mass spectrometry.

PubMed

Wilson, Christina R; Mulligan, Christopher C; Strueh, Kurt D; Stevenson, Gregory W; Hooser, Stephen B

2014-05-01

Desorption electrospray ionization mass spectrometry (DESI-MS) is an emerging analytical technique that permits the rapid and direct analysis of biological or environmental samples under ambient conditions. Highlighting the versatility of this technique, DESI-MS has been used for the rapid detection of illicit drugs, chemical warfare agents, agricultural chemicals, and pharmaceuticals from a variety of sample matrices. In diagnostic veterinary toxicology, analyzing samples using traditional analytical instrumentation typically includes extensive sample extraction procedures, which can be time consuming and labor intensive. Therefore, efforts to expedite sample analyses are a constant goal for diagnostic toxicology laboratories. In the current report, DESI-MS was used to directly analyze stomach contents from a dog exposed to the organophosphate insecticide terbufos. The total DESI-MS analysis time required to confirm the presence of terbufos and diagnose organophosphate poisoning in this case was approximately 5 min. This highlights the potential of this analytical technique in the field of veterinary toxicology for the rapid diagnosis and detection of toxicants in biological samples. © 2014 The Author(s).

Nursing Information Systems Requirements: A Milestone for Patient Outcome and Patient Safety Improvement.

PubMed

Farzandipour, Mehrdad; Meidani, Zahra; Riazi, Hossein; Sadeqi Jabali, Monireh

2016-12-01

Considering the integral role of understanding users' requirements in information system success, this research aimed to determine functional requirements of nursing information systems through a national survey. Delphi technique method was applied to conduct this study through three phases: focus group method modified Delphi technique and classic Delphi technique. A cross-sectional study was conducted to evaluate the proposed requirements within 15 general hospitals in Iran. Forty-three of 76 approved requirements were clinical, and 33 were administrative ones. Nurses' mean agreements for clinical requirements were higher than those of administrative requirements; minimum and maximum means of clinical requirements were 3.3 and 3.88, respectively. Minimum and maximum means of administrative requirements were 3.1 and 3.47, respectively. Research findings indicated that those information system requirements that support nurses in doing tasks including direct care, medicine prescription, patient treatment management, and patient safety have been the target of special attention. As nurses' requirements deal directly with patient outcome and patient safety, nursing information systems requirements should not only address automation but also nurses' tasks and work processes based on work analysis.

Transcranial direct current stimulation in psychiatric disorders

PubMed Central

Tortella, Gabriel; Casati, Roberta; Aparicio, Luana V M; Mantovani, Antonio; Senço, Natasha; D’Urso, Giordano; Brunelin, Jerome; Guarienti, Fabiana; Selingardi, Priscila Mara Lorencini; Muszkat, Débora; Junior, Bernardo de Sampaio Pereira; Valiengo, Leandro; Moffa, Adriano H; Simis, Marcel; Borrione, Lucas; Brunoni, André R

2015-01-01

The interest in non-invasive brain stimulation techniques is increasing in recent years. Among these techniques, transcranial direct current stimulation (tDCS) has been the subject of great interest among researchers because of its easiness to use, low cost, benign profile of side effects and encouraging results of research in the field. This interest has generated several studies and randomized clinical trials, particularly in psychiatry. In this review, we provide a summary of the development of the technique and its mechanism of action as well as a review of the methodological aspects of randomized clinical trials in psychiatry, including studies in affective disorders, schizophrenia, obsessive compulsive disorder, child psychiatry and substance use disorder. Finally, we provide an overview of tDCS use in cognitive enhancement as well as a discussion regarding its clinical use and regulatory and ethical issues. Although many promising results regarding tDCS efficacy were described, the total number of studies is still low, highlighting the need of further studies aiming to replicate these findings in larger samples as to provide a definite picture regarding tDCS efficacy in psychiatry. PMID:25815258

Analysis of Compounds Dissolved in Nonpolar Solvents by Electrospray Ionization on Conductive Nanomaterials

NASA Astrophysics Data System (ADS)

Xia, Bing; Gao, Yuanji; Ji, Baocheng; Ma, Fengwei; Ding, Lisheng; Zhou, Yan

2018-03-01

Electrospray ionization mass spectrometry (ESI-MS) technique has limitations in analysis of compounds that are dissolved in nonpolar solvents. In this study, ambient ionization of compounds in solvents that are not "friendly" to electrospray ionization, such as n-hexane, is achieved by conductive nanomaterials spray ionization (CNMSI) on nanomaterial emitters, including carbon nanotubes paper and mesodendritic silver covered metal, which applies high voltages to emitters made of these materials without the assistance of polar solvents. Although the time intensity curves (TIC) commonly vary from 4.5% to 23.7% over analyses, protonated molecular ions were found to be the most abundant species, demonstrating good reproducibility of the technique in terms of ionized species. Higher mass spectrometric responses are observed in analyzing nonpolar systems than polar systems. 2-Methoxyacetophenone, 4-methylacetophenone, benzothiazole, quinolone, and cycloheptanone as low as 2 pg in n-hexane can be directly detected using the developed method. The developed technique expands the analysis capability of ESI-MS for direct, online analysis of nonpolar systems, such as low polarity extracts, normal phase liquid chromatography eluates, and synthetic mixtures. [Figure not available: see fulltext.

Field Calibration of Wind Direction Sensor to the True North and Its Application to the Daegwanryung Wind Turbine Test Sites

PubMed Central

Lee, Jeong Wan

2008-01-01

This paper proposes a field calibration technique for aligning a wind direction sensor to the true north. The proposed technique uses the synchronized measurements of captured images by a camera, and the output voltage of a wind direction sensor. The true wind direction was evaluated through image processing techniques using the captured picture of the sensor with the least square sense. Then, the evaluated true value was compared with the measured output voltage of the sensor. This technique solves the discordance problem of the wind direction sensor in the process of installing meteorological mast. For this proposed technique, some uncertainty analyses are presented and the calibration accuracy is discussed. Finally, the proposed technique was applied to the real meteorological mast at the Daegwanryung test site, and the statistical analysis of the experimental testing estimated the values of stable misalignment and uncertainty level. In a strict sense, it is confirmed that the error range of the misalignment from the exact north could be expected to decrease within the credibility level. PMID:27873957

Application of Contact Mode AFM to Manufacturing Processes

NASA Astrophysics Data System (ADS)

Giordano, Michael A.; Schmid, Steven R.

A review of the application of contact mode atomic force microscopy (AFM) to manufacturing processes is presented. A brief introduction to common experimental techniques including hardness, scratch, and wear testing is presented, with a discussion of challenges in the extension of manufacturing scale investigations to the AFM. Differences between the macro- and nanoscales tests are discussed, including indentation size effects and their importance in the simulation of processes such as grinding. The basics of lubrication theory are presented and friction force microscopy is introduced as a method of investigating metal forming lubrication on the nano- and microscales that directly simulates tooling/workpiece asperity interactions. These concepts are followed by a discussion of their application to macroscale industrial manufacturing processes and direct correlations are made.

Rib fracture repair: indications, technical issues, and future directions.

PubMed

Nirula, Raminder; Diaz, Jose J; Trunkey, Donald D; Mayberry, John C

2009-01-01

Rib fracture repair has been performed at selected centers around the world for more than 50 years; however, the operative indications have not been established and are considered controversial. The outcome of a strictly nonoperative approach may not be optimal. Potential indications for rib fracture repair include flail chest, painful, movable rib fractures refractory to conventional pain management, chest wall deformity/defect, rib fracture nonunion, and during thoracotomy for other traumatic indication. Rib fracture repair is technically challenging secondary to the human rib's relatively thin cortex and its tendency to fracture obliquely. Nonetheless, several effective repair systems have been developed. Future directions for progress on this important surgical problem include the development of minimally invasive techniques and the conduct of multicenter, randomized trials.

Method for high resolution magnetic resonance analysis using magic angle technique

DOEpatents

Wind, Robert A.; Hu, Jian Zhi

2003-11-25

A method of performing a magnetic resonance analysis of a biological object that includes placing the biological object in a main magnetic field and in a radio frequency field, the main magnetic field having a static field direction; rotating the biological object at a rotational frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. According to another embodiment, the radio frequency is pulsed to provide a sequence capable of producing a spectrum that is substantially free of spinning sideband peaks.

Ethylene resistance in flowering ornamental plants – improvements and future perspectives

PubMed Central

Olsen, Andreas; Lütken, Henrik; Hegelund, Josefine Nymark; Müller, Renate

2015-01-01

Various strategies of plant breeding have been attempted in order to improve the ethylene resistance of flowering ornamental plants. These approaches span from conventional techniques such as simple cross-pollination to new breeding techniques which modify the plants genetically such as precise genome-editing. The main strategies target the ethylene pathway directly; others focus on changing the ethylene pathway indirectly via pathways that are known to be antagonistic to the ethylene pathway, e.g. increasing cytokinin levels. Many of the known elements of the ethylene pathway have been addressed experimentally with the aim of modulating the overall response of the plant to ethylene. Elements of the ethylene pathway that appear particularly promising in this respect include ethylene receptors as ETR1, and transcription factors such as EIN3. Both direct and indirect approaches seem to be successful, nevertheless, although genetic transformation using recombinant DNA has the ability to save much time in the breeding process, they are not readily used by breeders yet. This is primarily due to legislative issues, economic issues, difficulties of implementing this technology in some ornamental plants, as well as how these techniques are publically perceived, particularly in Europe. Recently, newer and more precise genome-editing techniques have become available and they are already being implemented in some crops. New breeding techniques may help change the current situation and pave the way toward a legal and public acceptance if products of these technologies are indistinguishable from plants obtained by conventional techniques. PMID:26504580

A Multimodal Dialog System for Language Assessment: Current State and Future Directions. Research Report. ETS RR-17-21

ERIC Educational Resources Information Center

Suendermann-Oeft, David; Ramanarayanan, Vikram; Yu, Zhou; Qian, Yao; Evanini, Keelan; Lange, Patrick; Wang, Xinhao; Zechner, Klaus

2017-01-01

We present work in progress on a multimodal dialog system for English language assessment using a modular cloud-based architecture adhering to open industry standards. Among the modules being developed for the system, multiple modules heavily exploit machine learning techniques, including speech recognition, spoken language proficiency rating,…

Windstorm Impact Reduction Implementation Plan

DTIC Science & Technology

2007-01-01

wind events, including hurricanes, tornadoes and straight line winds from thunderstorms. This information is repeated in brief during severe weather...event documentation and damage analyses. Better understanding of atmospheric dynamics of straight - line winds Wind observing systems and...Developed techniques for improved extreme wind speed maps Investigation of straight - line winds Wind speed and direction analysis for input to

Three Universities in Georgia, Kazakhstan and Kyrgyzstan: The Struggle against Corruption and for Social Cohesion

ERIC Educational Resources Information Center

Heyneman, Stephen P.

2007-01-01

Universities may contribute to a nation's social cohesion through both direct and indirect means. In their syllabi they may include techniques necessary for understanding complex social problems. Faculty may model good behaviour in terms of listening and understanding points of view that may contradict their own. University administrators may…

Enhancing the Scientific Process with Artificial Intelligence: Forest Science Applications

Treesearch

Ronald E. McRoberts; Daniel L. Schmoldt; H. Michael Rauscher

1991-01-01

Forestry, as a science, is a process for investigating nature. It consists of repeatedly cycling through a number of steps, including identifying knowledge gaps, creating knowledge to fill them, and organizing, evaluating, and delivering this knowledge. Much of this effort is directed toward creating abstract models of natural phenomena. The cognitive techniques of AI...

A novel technique to solve nonlinear higher-index Hessenberg differential-algebraic equations by Adomian decomposition method.

PubMed

Benhammouda, Brahim

2016-01-01

Since 1980, the Adomian decomposition method (ADM) has been extensively used as a simple powerful tool that applies directly to solve different kinds of nonlinear equations including functional, differential, integro-differential and algebraic equations. However, for differential-algebraic equations (DAEs) the ADM is applied only in four earlier works. There, the DAEs are first pre-processed by some transformations like index reductions before applying the ADM. The drawback of such transformations is that they can involve complex algorithms, can be computationally expensive and may lead to non-physical solutions. The purpose of this paper is to propose a novel technique that applies the ADM directly to solve a class of nonlinear higher-index Hessenberg DAEs systems efficiently. The main advantage of this technique is that; firstly it avoids complex transformations like index reductions and leads to a simple general algorithm. Secondly, it reduces the computational work by solving only linear algebraic systems with a constant coefficient matrix at each iteration, except for the first iteration where the algebraic system is nonlinear (if the DAE is nonlinear with respect to the algebraic variable). To demonstrate the effectiveness of the proposed technique, we apply it to a nonlinear index-three Hessenberg DAEs system with nonlinear algebraic constraints. This technique is straightforward and can be programmed in Maple or Mathematica to simulate real application problems.

Thermophysical properties of lunar materials. I - Thermal radiation properties of lunar materials from the Apollo missions

NASA Technical Reports Server (NTRS)

Birkebak, R. C.

1974-01-01

The successful landings on the moon of the Apollo flights and the return of samples of lunar surface material has permitted the measurement of the thermophysical properties necessary for heat transfer calculations. The characteristics of the Apollo samples are discussed along with remote sensing results which made it possible to deduce many of the thermophysical properties of the lunar surface. Definitions considered in connection with thermal radiation measurements include the bond albedo, the geometric albedo, the normal albedo, the directional reflectance, the bidirectional reflectance, and the directional emittance. The measurement techniques make use of a directional reflectance apparatus, a bidirectional reflectance apparatus, and a spectral emittance apparatus.

Nd:YAG photovaporization of residual equine guttural-pouch mycotic lesions after internal carotid occlusion

NASA Astrophysics Data System (ADS)

Tate, Lloyd P.; Tudor, R. A.; Little, Edwina D. E.

1998-07-01

Hospital records reviewed over a 12-year period determined that 6 horses had been presented for guttural pouch mycosis. All had a history of epistaxis and several had accompanying neurologic signs, including dysphagia. Initially, conformation of the disease was obtained by radiographic and endoscopic examinations. Surgical treatment was directed at controlling and preventing additional hemorrhage by occluding the arterial source of the hemorrhage. Direct treatment of the mycotic plaque present within the guttural pouch was conducted using transendoscopic technique to direct irradiation from the Nd:YAG laser. The protocol described for the laser application was successful in resolving the lesions and was less complicated and stressful than previously reported topically applied chemical protocols.

Fatigue resistance and crack propensity of large MOD composite resin restorations: direct versus CAD/CAM inlays.

PubMed

Batalha-Silva, Silvana; de Andrada, Mauro Amaral Caldeira; Maia, Hamilton Pires; Magne, Pascal

2013-03-01

To assess the influence of material/technique selection (direct vs. CAD/CAM inlays) for large MOD composite adhesive restorations and its effect on the crack propensity and in vitro accelerated fatigue resistance. A standardized MOD slot-type tooth preparation was applied to 32 extracted maxillary molars (5mm depth and 5mm bucco-palatal width) including immediately sealed dentin for the inlay group. Fifteen teeth were restored with direct composite resin restoration (Miris2) and 17 teeth received milled inlays using Paradigm MZ100 block in the CEREC machine. All inlays were adhesively luted with a light curing composite resin (Filtek Z100). Enamel shrinkage-induced cracks were tracked with photography and transillumination. Cyclic isometric chewing (5 Hz) was simulated, starting with a load of 200 N (5000 cycles), followed by stages of 400, 600, 800, 1000, 1200 and 1400 N at a maximum of 30,000 cycles each. Samples were loaded until fracture or to a maximum of 185,000 cycles. Teeth restored with the direct technique fractured at an average load of 1213 N and two of them withstood all loading cycles (survival=13%); with inlays, the survival rate was 100%. Most failures with Miris2 occurred above the CEJ and were re-restorable (67%), but generated more shrinkage-induced cracks (47% of the specimen vs. 7% for inlays). CAD/CAM MZ100 inlays increased the accelerated fatigue resistance and decreased the crack propensity of large MOD restorations when compared to direct restorations. While both restorative techniques yielded excellent fatigue results at physiological masticatory loads, CAD/CAM inlays seem more indicated for high-load patients. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review

NASA Astrophysics Data System (ADS)

Heard, W.; Song, B.; Williams, B.; Martin, B.; Sparks, P.; Nie, X.

2018-01-01

This review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior of geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Uniqueness and limitations for each experimental technique are also discussed.

Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review

DOE PAGES

Heard, W.; Song, B.; Williams, B.; ...

2018-01-03

Here, this review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior ofmore » geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Finally, uniqueness and limitations for each experimental technique are also discussed.« less

Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review

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

Heard, W.; Song, B.; Williams, B.

Here, this review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior ofmore » geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Finally, uniqueness and limitations for each experimental technique are also discussed.« less

Dielectrophoresis for Biomedical Sciences Applications: A Review

PubMed Central

Abd Rahman, Nurhaslina; Ibrahim, Fatimah; Yafouz, Bashar

2017-01-01

Dielectrophoresis (DEP) is a label-free, accurate, fast, low-cost diagnostic technique that uses the principles of polarization and the motion of bioparticles in applied electric fields. This technique has been proven to be beneficial in various fields, including environmental research, polymer research, biosensors, microfluidics, medicine and diagnostics. Biomedical science research is one of the major research areas that could potentially benefit from DEP technology for diverse applications. Nevertheless, many medical science research investigations have yet to benefit from the possibilities offered by DEP. This paper critically reviews the fundamentals, recent progress, current challenges, future directions and potential applications of research investigations in the medical sciences utilizing DEP technique. This review will also act as a guide and reference for medical researchers and scientists to explore and utilize the DEP technique in their research fields. PMID:28245552

Exploring Gigabyte Datasets in Real Time: Architectures, Interfaces and Time-Critical Design

NASA Technical Reports Server (NTRS)

Bryson, Steve; Gerald-Yamasaki, Michael (Technical Monitor)

1998-01-01

Architectures and Interfaces: The implications of real-time interaction on software architecture design: decoupling of interaction/graphics and computation into asynchronous processes. The performance requirements of graphics and computation for interaction. Time management in such an architecture. Examples of how visualization algorithms must be modified for high performance. Brief survey of interaction techniques and design, including direct manipulation and manipulation via widgets. talk discusses how human factors considerations drove the design and implementation of the virtual wind tunnel. Time-Critical Design: A survey of time-critical techniques for both computation and rendering. Emphasis on the assignment of a time budget to both the overall visualization environment and to each individual visualization technique in the environment. The estimation of the benefit and cost of an individual technique. Examples of the modification of visualization algorithms to allow time-critical control.

Stress Dependence of Ultrasonic Velocity in Unidirectional Graphite/Epoxy Composites for Longitudinal Waves Propagating Along the Direction of Stress

NASA Technical Reports Server (NTRS)

Prosser, William H.

1990-01-01

The first measurements of the stress induced velocity changes for propagation directions along the direction of applied stress in gr/ep composites have been presented. For propagation and stress direction perpendicular to the fiber direction, the data demonstrated a linear relation between normalized velocity shift and stress. After corrections for the delay line were made, the slope or SAC was determined and compared favorably with the expected value calculated from the previously determined nonlinear coefficients of this material. The ratio of the SAC to the elastic compliance for this direction of loading was evaluated and found to have a value similar to numerous other materials which have very different linear elastic properties. Measurements with stress and propagation along the fibers yielded unusual behavior. The curves were very nonlinear and even shifted direction at higher loads. The large scatter in the data due to bond variations made separation of material effects from bond induced artifacts impossible. Thus the SAC, R, and the remaining two unknown TOEC's could not be determined for this direction of propagation. These measurements further expand the basis of determining nonlinear elastic properties of composite materials. These properties may be useful in developing much needed NDE techniques to determine such important parameters as residual stress after cure and residual strength after impact damage. Additional study is needed to measure the nonlinear behavior in other composite materials including angle ply laminates. Also, other techniques to measure elastic nonlinearity such as harmonic generation should be applied to composites to improve the understanding of these properties and their importance.

In situ temperature monitoring in single-molecule FRET experiments

NASA Astrophysics Data System (ADS)

Hartmann, Andreas; Berndt, Frederic; Ollmann, Simon; Krainer, Georg; Schlierf, Michael

2018-03-01

Thermodynamic properties of single molecules including enthalpic and entropic contributions are often determined from experiments by a direct control and precise measurement of the local temperature. However, common temperature monitoring techniques using, for example, ultrafine temperature probes can lead to uncertainties as the probe cannot be placed in the vicinity of the molecule of interest. Here, we devised an approach to measure the local temperature in freely diffusing confocal single-molecule Förster Resonance Energy Transfer (smFRET) experiments in situ by directly adding the temperature-sensitive fluorescent dye Rhodamine B, whose fluorescence lifetime serves as a probe of the local temperature in the confocal volume. We demonstrate that the temperature and FRET efficiencies of static and dynamic molecules can be extracted within one measurement simultaneously, without the need of a reference chamber. We anticipate this technique to be particularly useful in the physicochemical analyses of temperature-dependent biomolecular processes from single-molecule measurements.

Some case studies of ocean wave physical processes utilizing the GSFC airborne radar ocean wave spectrometer

NASA Technical Reports Server (NTRS)

Jackson, F. C.

1984-01-01

The NASA K sub u band Radar Ocean Wave Spectrometer (ROWS) is an experimental prototype of a possible future satellite instrument for low data rate global waves measurements. The ROWS technique, which utilizes short pulse radar altimeters in a conical scan mode near vertical incidence to map the directional slope spectrum in wave number and azimuth, is briefly described. The potential of the technique is illustrated by some specific case studies of wave physical processes utilizing the aircraft ROWS data. These include: (1) an evaluation of numerical hindcast model performance in storm sea conditions, (2) a study of fetch limited wave growth, and (3) a study of the fully developed sea state. Results of these studies, which are briefly summarized, show how directional wave spectral observations from a mobile platform can contribute enormously to our understanding of wave physical processes.

Current and Prospective Methods for Plant Disease Detection

PubMed Central

Fang, Yi; Ramasamy, Ramaraja P.

2015-01-01

Food losses due to crop infections from pathogens such as bacteria, viruses and fungi are persistent issues in agriculture for centuries across the globe. In order to minimize the disease induced damage in crops during growth, harvest and postharvest processing, as well as to maximize productivity and ensure agricultural sustainability, advanced disease detection and prevention in crops are imperative. This paper reviews the direct and indirect disease identification methods currently used in agriculture. Laboratory-based techniques such as polymerase chain reaction (PCR), immunofluorescence (IF), fluorescence in-situ hybridization (FISH), enzyme-linked immunosorbent assay (ELISA), flow cytometry (FCM) and gas chromatography-mass spectrometry (GC-MS) are some of the direct detection methods. Indirect methods include thermography, fluorescence imaging and hyperspectral techniques. Finally, the review also provides a comprehensive overview of biosensors based on highly selective bio-recognition elements such as enzyme, antibody, DNA/RNA and bacteriophage as a new tool for the early identification of crop diseases. PMID:26287253

Barrier-breaking performance for industrial problems on the CRAY C916

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

Graffunder, S.K.

1993-12-31

Nine applications, including third-party codes, were submitted to the Gordon Bell Prize committee showing the CRAY C916 supercomputer providing record-breaking time to solution for industrial problems in several disciplines. Performance was obtained by balancing raw hardware speed; effective use of large, real, shared memory; compiler vectorization and autotasking; hand optimization; asynchronous I/O techniques; and new algorithms. The highest GFLOPS performance for the submissions was 11.1 GFLOPS out of a peak advertised performance of 16 GFLOPS for the CRAY C916 system. One program achieved a 15.45 speedup from the compiler with just two hand-inserted directives to scope variables properly for themore » mathematical library. New I/O techniques hide tens of gigabytes of I/O behind parallel computations. Finally, new iterative solver algorithms have demonstrated times to solution on 1 CPU as high as 70 times faster than the best direct solvers.« less

Interventional management of high-flow vascular malformations.

PubMed

Rosen, Robert J; Nassiri, Naiem; Drury, Jennifer E

2013-03-01

High-flow vascular malformations are among the most challenging lesions in the field of interventional radiology. For an optimal long-term result, the clinician must have a full understanding of the types of lesions, their natural history, appropriate diagnostic studies, indications for treatment, and all the treatment options, including surgery, embolization, laser, and pharmacotherapy. Surgery should, in general, be used primarily for lesions that are completely resectable or are so bulky that embolization would not provide a satisfactory result. Embolization techniques are directed at elimination of the nidus of the lesion, using a variety of penetrating embolic agents both by direct puncture and transcatheter approaches. This paper reviews the principles and techniques primarily involving embolization for lesions occurring in various parts of the body, emphasizing the lessons learned in treating more than 2000 patients over a 30-year period. Copyright © 2013 Elsevier Inc. All rights reserved.

Parallel computation in a three-dimensional elastic-plastic finite-element analysis

NASA Technical Reports Server (NTRS)

Shivakumar, K. N.; Bigelow, C. A.; Newman, J. C., Jr.

1992-01-01

A CRAY parallel processing technique called autotasking was implemented in a three-dimensional elasto-plastic finite-element code. The technique was evaluated on two CRAY supercomputers, a CRAY 2 and a CRAY Y-MP. Autotasking was implemented in all major portions of the code, except the matrix equations solver. Compiler directives alone were not able to properly multitask the code; user-inserted directives were required to achieve better performance. It was noted that the connect time, rather than wall-clock time, was more appropriate to determine speedup in multiuser environments. For a typical example problem, a speedup of 2.1 (1.8 when the solution time was included) was achieved in a dedicated environment and 1.7 (1.6 with solution time) in a multiuser environment on a four-processor CRAY 2 supercomputer. The speedup on a three-processor CRAY Y-MP was about 2.4 (2.0 with solution time) in a multiuser environment.

Direct mass spectrometry approaches to characterize polyphenol composition of complex samples.

PubMed

Fulcrand, Hélène; Mané, Carine; Preys, Sébastien; Mazerolles, Gérard; Bouchut, Claire; Mazauric, Jean-Paul; Souquet, Jean-Marc; Meudec, Emmanuelle; Li, Yan; Cole, Richard B; Cheynier, Véronique

2008-12-01

Lower molecular weight polyphenols including proanthocyanidin oligomers can be analyzed after HPLC separation on either reversed-phase or normal phase columns. However, these techniques are time consuming and can have poor resolution as polymer chain length and structural diversity increase. The detection of higher molecular weight compounds, as well as the determination of molecular weight distributions, remain major challenges in polyphenol analysis. Approaches based on direct mass spectrometry (MS) analysis that are proposed to help overcome these problems are reviewed. Thus, direct flow injection electrospray ionization mass spectrometry analysis can be used to establish polyphenol fingerprints of complex extracts such as in wine. This technique enabled discrimination of samples on the basis of their phenolic (i.e. anthocyanin, phenolic acid and flavan-3-ol) compositions, but larger oligomers and polymers were poorly detectable. Detection of higher molecular weight proanthocyanidins was also restricted with matrix-assisted laser desorption ionization (MALDI) MS, suggesting that they are difficult to desorb as gas-phase ions. The mass distribution of polymeric fractions could, however, be determined by analyzing the mass distributions of bovine serum albumin/proanthocyanidin complexes using MALDI-TOF-MS.

Fabrication and Characterization of New Composite Tio2 Carbon Nanofiber Anodic Catalyst Support for Direct Methanol Fuel Cell via Electrospinning Method

NASA Astrophysics Data System (ADS)

Abdullah, N.; Kamarudin, S. K.; Shyuan, L. K.; Karim, N. A.

2017-12-01

Platinum (Pt) is the common catalyst used in a direct methanol fuel cell (DMFC). However, Pt can lead towards catalyst poisoning by carbonaceous species, thus reduces the performance of DMFC. Thus, this study focuses on the fabrication of a new composite TiO2 carbon nanofiber anodic catalyst support for direct methanol fuel cells (DMFCs) via electrospinning technique. The distance between the tip and the collector (DTC) and the flow rate were examined as influencing parameters in the electrospinning technique. To ensure that the best catalytic material is fabricated, the nanofiber underwent several characterizations and electrochemical tests, including FTIR, XRD, FESEM, TEM, and cyclic voltammetry. The results show that D18, fabricated with a flow rate of 0.1 mLhr-1 and DTC of 18 cm, is an ultrafine nanofiber with the smallest average diameter, 136.73 ± 39.56 nm. It presented the highest catalyst activity and electrochemical active surface area value as 274.72 mAmg-1 and 226.75m2 g-1 PtRu, respectively, compared with the other samples.

Horizontal square buried sutures in a two-layered fashion enable direct primary closure for small circular wounds without dog-ears on the face.

PubMed

Matsunaga, Jun; Aiba, Setsuya

2005-05-01

Dog-ears often lead to lengthening of an excision, and it is desirable to avoid them. Facial skin, including the subepidermal connective tissue, is flexible and can be used advantageously to minimize dog-ears using a novel buried suture technique. After removing a round lesion, the first horizontal square buried suture (HSBS) was deeply placed parallel to the longitudinal direction of the defect beneath superficial fascia. After the first HSBS was tied, the defect became fusiform but was still largely open. The second HSBS was also placed parallel to the longitudinal direction of the defect but in more superficial fascia and using smaller horizontal buried loops than those of the first deep suture. After the second HSBS in the middle of the dermis was tied, the wound was almost closed without dog-ears. Consequently, few skin sutures were required to finish the operation. Using this technique, a small circular or oval defect on the face up to 1 cm in diameter can be closed without any additional excision of the skin and without creating dog-ears.

Fungal Genetics and Functional Diversity of Microbial Communities in the Soil under Long-Term Monoculture of Maize Using Different Cultivation Techniques

PubMed Central

Gałązka, Anna; Grządziel, Jarosław

2018-01-01

Fungal diversity in the soil may be limited under natural conditions by inappropriate environmental factors such as: nutrient resources, biotic and abiotic factors, tillage system and microbial interactions that prevent the occurrence or survival of the species in the environment. The aim of this paper was to determine fungal genetic diversity and community level physiological profiling of microbial communities in the soil under long-term maize monoculture. The experimental scheme involved four cultivation techniques: direct sowing (DS), reduced tillage (RT), full tillage (FT), and crop rotation (CR). Soil samples were taken in two stages: before sowing of maize (DSBS-direct sowing, RTBS-reduced tillage, FTBS-full tillage, CRBS-crop rotation) and the flowering stage of maize growth (DSF-direct sowing, RTF-reduced tillage, FTF-full tillage, CRF-crop rotation). The following plants were used in the crop rotation: spring barley, winter wheat and maize. The study included fungal genetic diversity assessment by ITS-1 next generation sequencing (NGS) analyses as well as the characterization of the catabolic potential of microbial communities (Biolog EcoPlates) in the soil under long-term monoculture of maize using different cultivation techniques. The results obtained from the ITS-1 NGS technique enabled to classify and correlate the fungi species or genus to the soil metabolome. The research methods used in this paper have contributed to a better understanding of genetic diversity and composition of the population of fungi in the soil under the influence of the changes that have occurred in the soil under long-term maize cultivation. In all cultivation techniques, the season had a great influence on the fungal genetic structure in the soil. Significant differences were found on the family level (P = 0.032, F = 3.895), genus level (P = 0.026, F = 3.313) and on the species level (P = 0.033, F = 2.718). This study has shown that: (1) fungal diversity was changed under the influence different cultivation techniques; (2) techniques of maize cultivation and season were an important factors that can influence the biochemical activity of soil. Maize cultivated in direct sowing did not cause negative changes in the fungal structure, even making it more stable during seasonal changes; (3) full tillage and crop rotation may change fungal community and soil function. PMID:29441054

Marginal adaptation of CAD-CAM onlays: Influence of preparation design and impression technique.

PubMed

Lima, Fernanda Ferruzzi; Neto, Constantino Fernandes; Rubo, José H; Santos, Gildo Coelho; Moraes Coelho Santos, Maria Jacinta

2018-03-15

Factors that may affect the marginal adaptation of computer-aided design and computer-aided manufacturing (CAD-CAM) restorations include preparation design, impression technique, and CAD-CAM system. The influence of impression technique and preparation design on CAD-CAM partial coverage restorations has not been fully addressed. The purpose of this in vitro study was to investigate the influence of direct and indirect digital impression techniques and 2 preparation designs on the marginal adaptation of CAD-CAM onlays. Two mesio-occlusal buccal onlay preparations with reduction of the mesiobuccal cusp were made: conventional preparation (CP) with a 1.2-mm modified shoulder margin and modified preparation (MP) flat cuspal reduction without shoulder. Virtual models were generated from each preparation by using a digital scanner (BlueCam; Dentsply Sirona) from the plastic teeth (direct digital impression) or from the stone dies (indirect digital impression). Onlays were designed using a CAD-CAM system (CEREC 4.0; Dentsply Sirona), and nanoceramic resin blocks (Lava Ultimate Restorative; 3M ESPE) were milled using the CEREC MCX milling machine. Marginal discrepancy was evaluated using an optical stereomicroscope at ×25 magnification in 18 locations distributed along the margins of the preparation. The data were analyzed by using 3-way ANOVA followed by the Tukey HSD test (α=.05). CP presented a statistically significant reduced average marginal adaptation (59 ±50 μm) than did MP (69 ±58 μm) (P<.001). The Tukey HSD test showed the presence of a significantly larger marginal discrepancy in the mesial and buccal locations of MP when compared with CP. Regarding impression techniques, the buccal location presented the smallest average marginal discrepancy in restorations fabricated with indirect impression when compared with direct impression (42 ±33 μm and 60 ±39 μm) (P<.001). The results showed that conventional preparation with a modified shoulder margin presented improved marginal adaptation compared with modified preparation with flat cuspal reduction. Direct and indirect digital impression techniques produced restorations within a clinically acceptable range; however, the indirect impression technique resulted in the fabrication of restorations with superior marginal adaptation on the buccal location. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Clinical management of scar tissue.

PubMed

Kasch, M C

1988-01-01

This paper will review the physiology of scar formation including the properties of wound healing and scar remodeling. A clinical scar management program that includes evaluation of scar adhesions and use of a variety of therapy interventions to minimize the formation of scar will be described. Use of compression, massage, splints and functional activities is included in this program. The information is applicable for the general occupational therapist who sees patients with hand dysfunction as well as a therapist specializing in hand rehabilitation. Every therapist who treats hand trauma must be familiar with the sequence and the properties of scar formation in order to reestablish tendon gliding and facilitate early remodeling of scar tissue. Many treatment techniques can be directed toward scar adhesions and no one method is totally effective when used alone; used together, these techniques can positively influence scar formation and restore maximal hand function.

Direct measurement of carbon-14 in carbon dioxide by liquid scintillation counting

NASA Technical Reports Server (NTRS)

Horrocks, D. L.

1969-01-01

Liquid scintillation counting technique is applied to the direct measurement of carbon-14 in carbon dioxide. This method has high counting efficiency and eliminates many of the basic problems encountered with previous techniques. The technique can be used to achieve a percent substitution reaction and is of interest as an analytical technique.

Wavelength Detuning Cross-Beam Energy Transfer Mitigation Scheme for Direct-Drive: Modeling and Evidence from National Ignition Facility Implosions

NASA Astrophysics Data System (ADS)

Marozas, J. A.

2017-10-01

Cross-beam energy transfer (CBET) has been shown to significantly reduce the laser absorption and implosion speed in direct-drive implosion experiments on OMEGA and the National Ignition Facility (NIF). Mitigating CBET assists in achieving ignition-relevant hot-spot pressures in deuterium-tritium cryogenic OMEGA implosions. In addition, reducing CBET permits lower, more hydrodynamically stable, in-flight aspect ratio ignition designs with smaller nonuniformity growth during the acceleration phase. Detuning the wavelengths of the crossing beams is one of several techniques under investigation at the University of Rochester to mitigate CBET. This talk will describe these techniques with an emphasis on wavelength detuning. Recent experiments designed and predicted using multidimensional hydrodynamic simulations including CBET on the NIF have exploited the wavelength arrangement of the NIF beam geometry to demonstrate CBET mitigation through wavelength detuning in polar-direct-drive (PDD) implosions. Shapes and trajectories inferred from time-resolved x-ray radiography of the imploding shell, scattered-light spectra, and hard x-ray spectra generated by suprathermal electrons all indicate a reduction in CBET. These results and their implications for direct-drive ignition will be presented and discussed. In addition, hydrodynamically scaled ignition-relevant designs for OMEGA implosions exploiting wavelength detuning will be presented. Changes required to the OMEGA laser to permit wavelength detuning will be discussed. Future plans for PDD on the NIF including more-uniform implosions with CBET mitigation will be explored. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Computer-delivered interventions for reducing alcohol consumption: meta-analysis and meta-regression using behaviour change techniques and theory.

PubMed

Black, Nicola; Mullan, Barbara; Sharpe, Louise

2016-09-01

The current aim was to examine the effectiveness of behaviour change techniques (BCTs), theory and other characteristics in increasing the effectiveness of computer-delivered interventions (CDIs) to reduce alcohol consumption. Included were randomised studies with a primary aim of reducing alcohol consumption, which compared self-directed CDIs to assessment-only control groups. CDIs were coded for the use of 42 BCTs from an alcohol-specific taxonomy, the use of theory according to a theory coding scheme and general characteristics such as length of the CDI. Effectiveness of CDIs was assessed using random-effects meta-analysis and the association between the moderators and effect size was assessed using univariate and multivariate meta-regression. Ninety-three CDIs were included in at least one analysis and produced small, significant effects on five outcomes (d+ = 0.07-0.15). Larger effects occurred with some personal contact, provision of normative information or feedback on performance, prompting commitment or goal review, the social norms approach and in samples with more women. Smaller effects occurred when information on the consequences of alcohol consumption was provided. These findings can be used to inform both intervention- and theory-development. Intervention developers should focus on, including specific, effective techniques, rather than many techniques or more-elaborate approaches.

Percutaneous Ultrasound-Guided TOPAZ Radiofrequency Coblation: A Novel Coaxial Technique for the Treatment of Recalcitrant Plantar Fasciitis-Our Experience.

PubMed

Shah, Amit; Best, Alistair J; Rennie, Winston J

2016-06-01

Various therapeutic options are available for treatment of recalcitrant plantar fasciitis. Studies using TOPAZ coblation (ArthroCare, Sunnyvale, CA) have had good early results. The current coblation technique involves a surgical incision or breach of the highly specialized plantar fat pad, which can be associated with risks. We describe a novel technique of ultrasound-guided percutaneous coblation with a lateral heel approach. Advantages include precise targeting of the plantar fascia by direct dynamic visualization of the coblation tip, a true percutaneous approach with a needle skin puncture (<5 mm), and preservation of the plantar fat pad by using a lateral heel approach. © 2016 by the American Institute of Ultrasound in Medicine.

Cosmological Particle Data Compression in Practice

NASA Astrophysics Data System (ADS)

Zeyen, M.; Ahrens, J.; Hagen, H.; Heitmann, K.; Habib, S.

2017-12-01

In cosmological simulations trillions of particles are handled and several terabytes of unstructured particle data are generated in each time step. Transferring this data directly from memory to disk in an uncompressed way results in a massive load on I/O and storage systems. Hence, one goal of domain scientists is to compress the data before storing it to disk while minimizing the loss of information. To prevent reading back uncompressed data from disk, this can be done in an in-situ process. Since the simulation continuously generates data, the available time for the compression of one time step is limited. Therefore, the evaluation of compression techniques has shifted from only focusing on compression rates to include run-times and scalability.In recent years several compression techniques for cosmological data have become available. These techniques can be either lossy or lossless, depending on the technique. For both cases, this study aims to evaluate and compare the state of the art compression techniques for unstructured particle data. This study focuses on the techniques available in the Blosc framework with its multi-threading support, the XZ Utils toolkit with the LZMA algorithm that achieves high compression rates, and the widespread FPZIP and ZFP methods for lossy compressions.For the investigated compression techniques, quantitative performance indicators such as compression rates, run-time/throughput, and reconstruction errors are measured. Based on these factors, this study offers a comprehensive analysis of the individual techniques and discusses their applicability for in-situ compression. In addition, domain specific measures are evaluated on the reconstructed data sets, and the relative error rates and statistical properties are analyzed and compared. Based on this study future challenges and directions in the compression of unstructured cosmological particle data were identified.

Evaluating motion processing algorithms for use with functional near-infrared spectroscopy data from young children.

PubMed

Delgado Reyes, Lourdes M; Bohache, Kevin; Wijeakumar, Sobanawartiny; Spencer, John P

2018-04-01

Motion artifacts are often a significant component of the measured signal in functional near-infrared spectroscopy (fNIRS) experiments. A variety of methods have been proposed to address this issue, including principal components analysis (PCA), correlation-based signal improvement (CBSI), wavelet filtering, and spline interpolation. The efficacy of these techniques has been compared using simulated data; however, our understanding of how these techniques fare when dealing with task-based cognitive data is limited. Brigadoi et al. compared motion correction techniques in a sample of adult data measured during a simple cognitive task. Wavelet filtering showed the most promise as an optimal technique for motion correction. Given that fNIRS is often used with infants and young children, it is critical to evaluate the effectiveness of motion correction techniques directly with data from these age groups. This study addresses that problem by evaluating motion correction algorithms implemented in HomER2. The efficacy of each technique was compared quantitatively using objective metrics related to the physiological properties of the hemodynamic response. Results showed that targeted PCA (tPCA), spline, and CBSI retained a higher number of trials. These techniques also performed well in direct head-to-head comparisons with the other approaches using quantitative metrics. The CBSI method corrected many of the artifacts present in our data; however, this approach produced sometimes unstable HRFs. The targeted PCA and spline methods proved to be the most robust, performing well across all comparison metrics. When compared head to head, tPCA consistently outperformed spline. We conclude, therefore, that tPCA is an effective technique for correcting motion artifacts in fNIRS data from young children.

3D shape measurement of automotive glass by using a fringe reflection technique

NASA Astrophysics Data System (ADS)

Skydan, O. A.; Lalor, M. J.; Burton, D. R.

2007-01-01

In automotive and glass making industries, there is a need for accurately measuring the 3D shapes of reflective surfaces to speed up and ensure product development and manufacturing quality by using non-contact techniques. This paper describes a technique for the measurement of non-full-field reflective surfaces of automotive glass by using a fringe reflection technique. Physical properties of the measurement surfaces do not allow us to apply optical geometries used in existing techniques for surface measurement based upon direct fringe pattern illumination. However, this property of surface reflectivity can be used to implement similar ideas from existing techniques in a new improved method. In other words, the reflective surface can be used as a mirror to reflect illuminated fringe patterns onto a screen behind. It has been found that in the case of implementing the reflective fringe technique, the phase-shift distribution depends not only on the height of the object but also on the slope at each measurement point. This requires the solving of differential equations to find the surface slope and height distributions in the x and y directions and development of the additional height reconstruction algorithms. The main focus has been made on developing a mathematical model of the optical sub-system and discussing ways for its practical implementation including calibration procedures. A number of implemented image processing algorithms for system calibration and data analysis are discussed and two experimental results are given for automotive glass surfaces with different shapes and defects. The proposed technique showed the ability to provide accurate non-destructive measurement of 3D shapes of the reflective automotive glass surfaces and can be used as a key element for a glass shape quality control system on-line or in a laboratory environment.

The role of simulation in surgical training.

PubMed Central

Torkington, J.; Smith, S. G.; Rees, B. I.; Darzi, A.

2000-01-01

Surgical training has undergone many changes in the last decade. One outcome of these changes is the interest that has been generated in the possibility of training surgical skills outside the operating theatre. Simulation of surgical procedures and human tissue, if perfect, would allow complete transfer of techniques learnt in a skills laboratory directly to the operating theatre. Several techniques of simulation are available including artificial tissues, animal models and virtual reality computer simulation. Each is discussed in this article and their advantages and disadvantages considered. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:10743423

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

NASA Astrophysics Data System (ADS)

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

1982-10-01

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

Finite element analysis and modal testing of a rotating wind turbine

NASA Astrophysics Data System (ADS)

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

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

Auger spectroscopy of fracture surfaces of ceramics

NASA Technical Reports Server (NTRS)

Marcus, H. L.; Harris, J. M.; Szalkowski, F. J.

1974-01-01

Results of Auger electron spectroscopy (AES) studies of fracture surfaces in a series of ceramic materials, including Al2O3, MgO, and Si3N4, which were formed using different processing techniques. AES on the fractured surface of a lunar sample is also discussed. Scanning electron micrograph fractography is used to relate the surface chemistry to the failure mode. Combined argon ion sputtering and AES studies demonstrate the local variations in chemistry near the fracture surface. The problems associated with doing AES in insulators are also discussed, and the experimental techniques directed toward solving them are described.

Echocardiographic Evaluation of Left Atrial Mechanics: Function, History, Novel Techniques, Advantages, and Pitfalls.

PubMed

Leischik, Roman; Littwitz, Henning; Dworrak, Birgit; Garg, Pankaj; Zhu, Meihua; Sahn, David J; Horlitz, Marc

2015-01-01

Left atrial (LA) functional analysis has an established role in assessing left ventricular diastolic function. The current standard echocardiographic parameters used to study left ventricular diastolic function include pulsed-wave Doppler mitral inflow analysis, tissue Doppler imaging measurements, and LA dimension estimation. However, the above-mentioned parameters do not directly quantify LA performance. Deformation studies using strain and strain-rate imaging to assess LA function were validated in previous research, but this technique is not currently used in routine clinical practice. This review discusses the history, importance, and pitfalls of strain technology for the analysis of LA mechanics.

Methods and apparatus for analysis of chromatographic migration patterns

DOEpatents

Stockham, Thomas G.; Ives, Jeffrey T.

1993-01-01

A method and apparatus for sharpening signal peaks in a signal representing the distribution of biological or chemical components of a mixture separated by a chromatographic technique such as, but not limited to, electrophoresis. A key step in the method is the use of a blind deconvolution technique, presently embodied as homomorphic filtering, to reduce the contribution of a blurring function to the signal encoding the peaks of the distribution. The invention further includes steps and apparatus directed to determination of a nucleotide sequence from a set of four such signals representing DNA sequence data derived by electrophoretic means.

Surgical Management of Common Disorders of Feedlot Calves.

PubMed

Miesner, Matt D; Anderson, David E

2015-11-01

Procedures to improve animal and handler safety, shape production parameters, and directly address the prosperity of individuals in need of assistance are performed routinely. Techniques to accomplish these tasks have been described in many venues. Painful procedures are expected in feedlot practice. Assessing and managing pain and welfare for these procedures has strengthened significantly over the past decade to address increased public concerns and also to support the desires of the operators/managers to progress. Methods to perform common procedures are described, including evidence and techniques for managing the pain and distress while performing them. Published by Elsevier Inc.

Social impact analysis: monetary valuation

USGS Publications Warehouse

Wainger, Lisa A.; Johnston, Robert J.; Bagstad, Kenneth J.; Casey, Frank; Vegh, Tibor

2014-01-01

This section provides basic guidance for using and conducting economic valuation, including criteria for judging whether valuation is appropriate for supporting decisions. It provides an introduction to the economic techniques used to measure changes in social welfare and describes which methods may be most appropriate for use in valuing particular ecosystem services. Rather than providing comprehensive valuation instructions,it directs readers to additional resources.More generally, it establishes that the valuation of ecosystem services is grounded in a long history of non-market valuation and discusses how ecosystem services valuation can be conducted within established economic theory and techniques.

Surgery for gastrinoma.

PubMed

Cisco, Robin M; Norton, Jeffrey A

2007-01-01

Surgery has been demonstrated to offer potential for cure in patients who have sporadic ZES and improved tumor-related survival in all patients who have ZES with gastrinomas larger than 2.5 cm. Techniques such as preoperative localization with SRS and intraoperative localization with duodenotomy have improved the effectiveness of surgical intervention for ZES. Future directions for investigation should include better defining the role of preoperative EUS and developing new, more sensitive techniques for preoperative localization. More research also is needed to define the appropriate indications for pancreaticoduodenectomy in ZES and to determine whether proximal vagotomy should be performed at the time of surgical exploration.

Self-control program in the treatment of obesity.

PubMed

Rosen, L W

1981-06-01

In a pilot study utilizing self-control techniques for the purpose of modifying the cue-reactive eating habits of obese patients, three subjects maintained a continuous weight loss throughout the first year of treatment. Techniques included goal setting, self-monitoring, brief delay and self-confrontation prior to eating unauthorized food and direct observation of oneself in a mirror when eating unauthorized food. All patients are expected to remain in treatment for the foreseeable future with no termination of the program despite apparent success with regard to control of their feeding disturbance. The rationale for this approach is discussed.

VATS intraoperative tattooing to facilitate solitary pulmonary nodule resection.

PubMed

Willekes, Lourens; Boutros, Cherif; Goldfarb, Michael A

2008-03-19

Video-assisted thoracic surgery (VATS) has become routine and widely accepted for the removal of solitary pulmonary nodules of unknown etiology. Thoracosopic techniques continue to evolve with better instruments, robotic applications, and increased patient acceptance and awareness. Several techniques have been described to localize peripheral pulmonary nodules, including pre-operative CT-guided tattooing with methylene blue, CT scan guided spiral/hook wire placement, and transthoracic ultrasound. As pulmonary surgeons well know, the lung and visceral pleura may appear featureless on top of a pulmonary nodule. This paper presents a rapid, direct and inexpensive approach to peripheral lung lesion resection by marking the lung parenchyma on top of the nodule using direct methylene blue injection. In two patients with peripherally located lung nodules (n = 3) scheduled for VATS, we used direct methylene blue injection for intraoperative localization of the pulmonary nodule. Our technique was the following: After finger palpation of the lung, a spinal 25 gauge needle was inserted through an existing port and 0.1 ml of methylene blue was used to tattoo the pleura perpendicular to the localized nodule. The methylene blue tattoo immediately marks the lung surface over the nodule. The surgeon avoids repeated finger palpation, while lining up stapler, graspers and camera, because of the visible tattoo. Our technique eliminates regrasping and repalpating the lung once again to identify a non marked lesion. Three lung nodules were resected in two patients. Once each lesion was palpated it was marked, and the area was resected with security of accurate localization. All lung nodules were resected in totality with normal lung parenchymal margins. Our technique added about one minute to the operative time. The two patients were discharged home on the second postoperative day, with no morbidity. VATS with intraoperative tattooing is a safe, easy, and accurate technique to streamline and efficiently resect solitary pulmonary nodules.

Methods of measurement for semiconductor materials, process control, and devices

NASA Technical Reports Server (NTRS)

Bullis, W. M. (Editor)

1972-01-01

Activities directed toward the development of methods of measurement for semiconductor materials, process control, and devices are described. Topics investigated include: measurements of transistor delay time; application of the infrared response technique to the study of radiation-damaged, lithium-drifted silicon detectors; and identification of a condition that minimizes wire flexure and reduces the failure rate of wire bonds in transistors and integrated circuits under slow thermal cycling conditions. Supplementary data concerning staff, standards committee activities, technical services, and publications are included as appendixes.

ERDA's Chemical Energy Storage Program

NASA Technical Reports Server (NTRS)

Swisher, J. H.; Kelley, J. H.

1977-01-01

The Chemical Energy Storage Program is described with emphasis on hydrogen storage. Storage techniques considered include pressurized hydrogen gas storage, cryogenic liquid hydrogen storage, storage in hydride compounds, and aromatic-alicyclic hydrogen storage. Some uses of energy storage are suggested. Information on hydrogen production and hydrogen use is also presented. Applications of hydrogen energy systems include storage of hydrogen for utilities load leveling, industrial marketing of hydrogen both as a chemical and as a fuel, natural gas supplementation, vehicular applications, and direct substitution for natural gas.

Proceedings of the Workshop on Aquatic Ecosystem Modeling and Assessment Techniques for Application within the U.S. Army Corps of Engineers.

DTIC Science & Technology

1998-04-01

Dr. Kennedy. Others who contributed directly to planning for the workshop included Drs. Todd S. Bridges, Mark S. Dortch, John M. Nestler, and...Quality and Contaminants Modeling Branch, EPED; Dr. Price, Chief, EPED; and Dr. John Harrison, Director, EL. At the time of the publication of this...this project is characterized by broad multi- agency interest and involvement, including several USACE Districts (St Paul , Rock Island, St, Louis

Lyme disease and conservation

USGS Publications Warehouse

Ginsberg, H.

1994-01-01

Lyme disease is a tick-borne illness that is wide-spread in North America, especially in the northeastern and northcentral United States. This disease could negatively influence efforts to conserve natural populations in two ways: (1) the disease could directly affect wild animal health; and (2) tick control efforts could adversely affect natural populations and communities. Lyme disease affects several domestic animals, but symptoms have been reported in only a few wild species. Direct effects of Lyme disease on wild animal populations have not been reported, but the disease should be considered as a possible cause in cases of unexplained population declines in endemic areas. Methods available to manage ticks and Lyme disease include human self-protection techniques, manipulation of habitats and hosts species populations, biological control, and pesticide applications. The diversity of available techniques allows selection of approaches to minimize environmental effects by (1) emphasizing personal protection techniques, (2) carefully targeting management efforts to maximize efficiency, and (3) integrating environmentally benign techniques to improve management while avoiding broad-scale environmentally destructive approaches. The environmental effects of Lyme disease depend, to a large extent, on the methods chosen to minimize human exposure to infected ticks. Conservation biologists can help design tick management programs that effectively lower the incidence of human Lyme disease while simultaneously minimizing negative effects on natural populations.

The British Geological Survey and the petroleum industry

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

Chesher, J.A.

1995-08-01

The British Geological Survey is the UK`s national centre for earth science information with a parallel remit to operate internationally. The Survey`s work covers the full geoscience spectrum in energy, mineral and groundwater resources and associated implications for land use, geological hazards and environmental impact. Much of the work is conducted in collaboration with industry and academia, including joint funding opportunities. Activities relating directly to hydrocarbons include basin analysis, offshore geoscience mapping, hazard assessment, fracture characterization, biostratigraphy, sedimentology, seismology, geomagnetism and frontier data acquisition techniques, offshore. The BGS poster presentation illustrates the value of the collaborative approach through consortia supportmore » for regional offshore surveys, geotechnical hazard assessments and state-of-the-art R & D into multicomponent seismic imaging techniques, among others.« 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.

A catalogue of devices applicable to the measurement of boundary layers and wakes on flight vehicles

NASA Technical Reports Server (NTRS)

Miley, S. J.

1972-01-01

A literature search was conducted to assemble a catalog of devices and techniques which have possible application to boundary layer and wake measurements on flight vehicles. The indices used in the search were NACA, NASA STAR, IAA, USGRDR and Applied Science and Technology Index. The period covered was 1950 through 1970. The devices contained in the catalog were restricted to those that provided essentially direct measurement of velocities, pressures and shear stresses. Pertinent material was included in the catalog if it contained either an adequate description of a device and associated performance data or a presentation of applicable information on a particular measurement theory and/or technique. When available, illustrations showing the configuration of the device and test condition data were also included.

Determining Directional Dependency in Causal Associations

PubMed Central

Pornprasertmanit, Sunthud; Little, Todd D.

2014-01-01

Directional dependency is a method to determine the likely causal direction of effect between two variables. This article aims to critique and improve upon the use of directional dependency as a technique to infer causal associations. We comment on several issues raised by von Eye and DeShon (2012), including: encouraging the use of the signs of skewness and excessive kurtosis of both variables, discouraging the use of D’Agostino’s K2, and encouraging the use of directional dependency to compare variables only within time points. We offer improved steps for determining directional dependency that fix the problems we note. Next, we discuss how to integrate directional dependency into longitudinal data analysis with two variables. We also examine the accuracy of directional dependency evaluations when several regression assumptions are violated. Directional dependency can suggest the direction of a relation if (a) the regression error in population is normal, (b) an unobserved explanatory variable correlates with any variables equal to or less than .2, (c) a curvilinear relation between both variables is not strong (standardized regression coefficient ≤ .2), (d) there are no bivariate outliers, and (e) both variables are continuous. PMID:24683282

Abutment misfit in implant-supported prostheses manufactured by casting technique: An integrative review

PubMed Central

Pereira, Lorena M. S.; Sordi, Mariane B.; Magini, Ricardo S.; Calazans Duarte, Antônio R.; M. Souza, Júlio C.

2017-01-01

The aim of this study was to perform an integrative review of the literature on the clinically usual prosthesis-abutment misfit over implant-supported structures manufactured by conventional casting technique. The present integrative review used the PRISMA methodology. A bibliographical search was conducted on the following electronic databases: MEDLINE/PubMed (National Library of Medicine), Scopus (Elsevier), ScienceDirect (Elsevier), Web of Science (Thomson Reuters Scientific), Latin American and Caribbean Center on Health Sciences Information (BIREME), and Virtual Health Library (BVS). A total of 11 relevant studies were selected for qualitative analysis. The prosthetic-abutment vertical misfit considered clinically usual ranged from 50 to 160 μm. The vertical misfit depends on several steps during technical manufacturing techniques, which includes the materials and technical procedures. Lower values in misfit are recorded when precious metal or titanium alloys are utilized. Although a vertical misfit mean value of 100 μm has been considered clinically usual, most of the previous studies included in this revision showed lower mean values. PMID:29279686

T1ρ MR Imaging of Human Musculoskeletal System

PubMed Central

Wang, Ligong; Regatte, Ravinder R.

2014-01-01

Magnetic resonance imaging (MRI) offers the direct visualization of human musculoskeletal (MSK) system, especially all diarthrodial tissues including cartilage, bone, menisci, ligaments, tendon, hip, synovium etc. Conventional MR imaging techniques based on T1- and T2-weighted, proton density (PD) contrast are inconclusive in quantifying early biochemically degenerative changes in MSK system in general and articular cartilage in particular. In recent years, quantitative MR parameter mapping techniques have been used to quantify the biochemical changes in articular cartilage with a special emphasis on evaluating joint injury, cartilage degeneration, and soft tissue repair. In this article, we will focus on cartilage biochemical composition, basic principles of T1ρ MR imaging, implementation of T1ρ pulse sequences, biochemical validation, and summarize the potential applications of T1ρ MR imaging technique in MSK diseases including osteoarthritis (OA), anterior cruciate ligament (ACL) injury, and knee joint repair. Finally, we will also review the potential advantages, challenges, and future prospects of T1ρ MR imaging for widespread clinical translation. PMID:24935818

Digital stereo-holographic microscopy for studying three-dimensional particle dynamics

NASA Astrophysics Data System (ADS)

Byeon, Hyeokjun; Go, Taesik; Lee, Sang Joon

2018-06-01

A digital stereo-holographic microscopy (DsHM) with two viewing angles is proposed to measure 3D information of microscale particles. This approach includes two volumetric recordings and numerical reconstruction, and it involves the combination of separately reconstructed holograms. The 3D positional information of a particle was determined by searching the center of the overlapped reconstructed volume. After confirming the proposed technique using static spherical particles, the 3D information of moving particles suspended in a Hagen-Poiseiulle flow was successfully obtained. Moreover, the 3D information of nonspherical particles, including ellipsoidal particles and red blood cells, were measured using the proposed technique. In addition to 3D positional information, the orientation and shape of the test samples were obtained from the plane images by slicing the overlapped volume perpendicular to the directions of the image recordings. This DsHM technique will be useful in analyzing the 3D dynamic behavior of various nonspherical particles, which cannot be measured by conventional digital holographic microscopy.

T₁ρ MRI of human musculoskeletal system.

PubMed

Wang, Ligong; Regatte, Ravinder R

2015-03-01

Magnetic resonance imaging (MRI) offers the direct visualization of the human musculoskeletal (MSK) system, especially all diarthrodial tissues including cartilage, bone, menisci, ligaments, tendon, hip, synovium, etc. Conventional MRI techniques based on T1 - and T2 -weighted, proton density (PD) contrast are inconclusive in quantifying early biochemically degenerative changes in MSK system in general and articular cartilage in particular. In recent years, quantitative MR parameter mapping techniques have been used to quantify the biochemical changes in articular cartilage, with a special emphasis on evaluating joint injury, cartilage degeneration, and soft tissue repair. In this article we focus on cartilage biochemical composition, basic principles of T1ρ MRI, implementation of T1ρ pulse sequences, biochemical validation, and summarize the potential applications of the T1ρ MRI technique in MSK diseases including osteoarthritis (OA), anterior cruciate ligament (ACL) injury, and knee joint repair. Finally, we also review the potential advantages, challenges, and future prospects of T1ρ MRI for widespread clinical translation. © 2014 Wiley Periodicals, Inc.

Miscellaneous methods for measuring matric or water potential

USGS Publications Warehouse

Scanlon, Bridget R.; Andraski, Brian J.; Bilskie, Jim; Dane, Jacob H.; Topp, G. Clarke

2002-01-01

A variety of techniques to measure matric potential or water potential in the laboratory and in the field are described in this section. The techniques described herein require equilibration of some medium whose matric or water potential can be determined from previous calibration or can be measured directly. Under equilibrium conditions the matric or water potential of the medium is equal to that of the soil. The techniques can be divided into: (i) those that measure matric potential and (ii) those that measure water potential (sum of matric and osmotic potentials). Matric potential is determined when the sensor matrix is in direct contact with the soil, so salts are free to diffuse in or out of the sensor matrix, and the equilibrium measurement therefore reflects matric forces acting on the water. Water potential is determined when the sensor is separated from the soil by a vapor gap, so salts are not free to move in or out of the sensor, and the equilibrium measurement reflects the sum of the matric and osmotic forces acting on the water.Seven different techniques are described in this section. Those that measure matric potential include (i) heat dissipation sensors, (ii) electrical resistance sensors, (iii) frequency domain and time domain sensors, and (iv) electro-optical switches. A method that can be used to measure matric potential or water potential is the (v) filter paper method. Techniques that measure water potential include (vi) the Dew Point Potentiameter (Decagon Devices, Inc., Pullman, WA1) (water activity meter) and (vii) vapor equilibration.The first four techniques are electronically based methods for measuring matric potential. Heat dissipation sensors and electrical resistance sensors infer matric potential from previously determined calibration relations between sensor heat dissipation or electrical resistance and matric potential. Frequency-domain and timedomain matric potential sensors measure water content, which is related to matric potential of the sensor through calibration. Electro-optical switches measure changes in light transmission through thin, nylon filters as they absorb or desorb water in response to changes in matric potential. Heat dissipation sensors and electrical resistance sensors are used primarily in the field to provide information on matric potential. Frequency domain matric potential sensors are new and have not been widely used. Time domain matric potential sensors and electro-optical switches are new and have not been commercialized. For the fifth technique, filter paper is used as the standard matrix. The filter paper technique measures matric potential when the filter paper is in direct contact with soil or water potential when separated from soil by a vapor gap. The Dew Point Potentiameter calculates water potential from the measured dew point and sample temperature. The vapor equilibration technique involves equilibration of soil samples with salt solutions of known osmotic potential. The filter paper, Dew Point Potentiameter, and vapor equilibration techniques are generally used in the laboratory to measure water potential of disturbed field samples or to measure water potential for water retention functions.

Lean direct wall fuel injection method and devices

NASA Technical Reports Server (NTRS)

Choi, Kyung J. (Inventor); Tacina, Robert (Inventor)

2000-01-01

A fuel combustion chamber, and a method of and a nozzle for mixing liquid fuel and air in the fuel combustion chamber in lean direct injection combustion for advanced gas turbine engines, including aircraft engines. Liquid fuel in a form of jet is injected directly into a cylindrical combustion chamber from the combustion chamber wall surface in a direction opposite to the direction of the swirling air at an angle of from about 50.degree. to about 60.degree. with respect to a tangential line of the cylindrical combustion chamber and at a fuel-lean condition, with a liquid droplet momentum to air momentum ratio in the range of from about 0.05 to about 0.12. Advanced gas turbines benefit from lean direct wall injection combustion. The lean direct wall injection technique of the present invention provides fast, uniform, well-stirred mixing of fuel and air. In addition, in order to further improve combustion, the fuel can be injected at a venturi located in the combustion chamber at a point adjacent the air swirler.

The Scharff-technique: eliciting intelligence from human sources.

PubMed

Oleszkiewicz, Simon; Granhag, Pär Anders; Montecinos, Sebastian Cancino

2014-10-01

This study is on how to elicit intelligence from human sources. We compared the efficacy of two human intelligence gathering techniques: the Scharff-technique (conceptualized as four different tactics) and the Direct Approach (a combination of open and direct questions). Participants (N = 60) were asked to take on the role of "sources" and were given information about a planned terrorist attack. They were to reveal part of this information in an upcoming interview. Critically, the participants were instructed to strike a balance between not revealing too much or too little information. As predicted, the participants revealed significantly more, and more precise, new information when interviewed with the Scharff-technique (vs. the Direct Approach). Furthermore, and as predicted, the participants in the Scharff condition underestimated how much new information they revealed whereas the participants in the Direct Approach overestimated how much new information they revealed. The study provides rather strong support for the Scharff-technique as an effective human intelligence gathering technique. PsycINFO Database Record (c) 2014 APA, all rights reserved.

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

NASA Technical Reports Server (NTRS)

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

1982-01-01

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

Practical Guidance for Conducting Mediation Analysis With Multiple Mediators Using Inverse Odds Ratio Weighting

PubMed Central

Nguyen, Quynh C.; Osypuk, Theresa L.; Schmidt, Nicole M.; Glymour, M. Maria; Tchetgen Tchetgen, Eric J.

2015-01-01

Despite the recent flourishing of mediation analysis techniques, many modern approaches are difficult to implement or applicable to only a restricted range of regression models. This report provides practical guidance for implementing a new technique utilizing inverse odds ratio weighting (IORW) to estimate natural direct and indirect effects for mediation analyses. IORW takes advantage of the odds ratio's invariance property and condenses information on the odds ratio for the relationship between the exposure (treatment) and multiple mediators, conditional on covariates, by regressing exposure on mediators and covariates. The inverse of the covariate-adjusted exposure-mediator odds ratio association is used to weight the primary analytical regression of the outcome on treatment. The treatment coefficient in such a weighted regression estimates the natural direct effect of treatment on the outcome, and indirect effects are identified by subtracting direct effects from total effects. Weighting renders treatment and mediators independent, thereby deactivating indirect pathways of the mediators. This new mediation technique accommodates multiple discrete or continuous mediators. IORW is easily implemented and is appropriate for any standard regression model, including quantile regression and survival analysis. An empirical example is given using data from the Moving to Opportunity (1994–2002) experiment, testing whether neighborhood context mediated the effects of a housing voucher program on obesity. Relevant Stata code (StataCorp LP, College Station, Texas) is provided. PMID:25693776

Marketing techniques in television advertisements of food and drinks directed at children in Spain, 2012.

PubMed

León-Flández, Karimen; Royo-Bordonada, Miguel Ángel; Moya-Geromini, María Ángeles; Bosqued-Estefanía, María José; López-Jurado, Lázaro; Damián, Javier

2018-07-01

To analyse marketing techniques used in television advertisements of food and drinks (AFDs) directed to children, and their nutritional quality. This is a cross-sectional study of television AFDs directed to children in Spain over 7 days in 2012. Primary appeal, persuasive and nutritional marketing techniques, and links to Internet were registered. The foods were classified according to their nutritional quality using an international codification system and the UK nutrient profile model. Frequency of AFDs using marketing techniques and percentages for unhealthy products were calculated. Taste and fun were the main primary appeals used. Persuasive and nutritional marketing techniques and links to Internet were used in 61%, 68.5% and 65.2% of AFDs, respectively. These techniques were more common during weekdays, enhanced protection time slots and on channels with particular appeal to children. More than two-thirds of AFDs using these techniques were for unhealthy products, reaching 96.2% of AFDs with premium offers and gifts. There is an extensive use of marketing techniques in television AFDs directed to children in Spain. Most products advertised were unhealthy, so stronger governmental regulations are required.

[The stamp technique for direct composite restoration].

PubMed

Perrin, Philippe; Zimmerli, Brigitte; Jacky, Daniel; Lussi, Adrian; Helbling, Christoph; Ramseyer, Simon

2013-01-01

The indications for direct resin composite restorations are nowadays extended due to the development of modern resin materials with improved material properties. However, there are still some difficulties regarding handling of resin composite material, especially in large restorations. The reconstruction of a functional and individual occlusion is difficult to achieve with direct application techniques. The aim of the present publication was to introduce a new "stamp"-technique for placing large composite restorations. The procedure of this "stamp"-technique is presented by three typical indications: large single-tooth restoration, occlusal rehabilitation of a compromised occlusal surface due to erosions and direct fibre-reinforced fixed partial denture. A step-by-step description of the technique and clinical figures illustrates the method. Large single-tooth restorations can be built-up with individual, two- piece silicone stamps. Large occlusal abrasive and/or erosive defects can be restored by copying the wax-up from the dental technician using the "stamp"-technique. Even fiber-reinforced resin-bonded fixed partial dentures can be formed with this intraoral technique with more precision and within a shorter treatment time. The presented "stamp"-technique facilitates the placement of large restoration with composite and can be recommended for the clinical use.

Microstructurally tailored ceramics for advanced energy applications by thermoreversible gelcasting

NASA Astrophysics Data System (ADS)

Shanti, Noah Omar

Thermoreversible gelcasting (TRG) is an advantageous technique for rapidly producing bulk, net-shape ceramics and laminates. In this method, ceramic powder is suspended in warm acrylate triblock copolymer/alcohol solutions that reversibly gel upon cooling by the formation of endblock aggregates, to produce slurries which are cast into molds. Gel properties can be tailored by controlling the endblock and midblock lengths of the copolymer network-former and selecting an appropriate alcohol solvent. This research focuses on expanding and improving TRG techniques, focusing specifically on advanced energy applications including the solid oxide fuel cell (SOFC). Rapid drying of filled gels can lead to warping and cracking caused by high differential capillary stresses. A new drying technique using concentrated, alcohol-based solutions as liquid desiccants (LDs) to greatly reduce warping is introduced. The optimal LD is a poly(tert-butyl acrylate)/isopropyl alcohol solution with 5 mol% tert-butyl acrylate units. Alcohol emissions during drying are completely eliminated by combining initial drying in an LD with final stage drying in a vacuum oven having an in-line solvent trap. Porous ceramics are important structures for many applications, including SOFCs. Pore network geometries are tailored by the addition of fugitive fillers to TRG slurries. Uniform spherical, bimodal spherical and uniform fibrous fillers are used. Three-dimensional pore structures are visualized by X-ray computed tomography, allowing for direct measurements of physical parameters such as concentration and morphology as well as transport properties such as tortuosity. Tortuosity values as low as 1.52 are achieved when 60 vol% of solids are uniform spherical filler. Functionally graded laminates with layers ranging from 10 mum to > 1 mm thick are produced with a new technique that combines TRG with tape casting. Gels used for bulk casting are not suitable for use with tape casting, and appropriate base gels are selected for this technique. Each layer is cast in a single pass, and the layers are directly laminated. The anode support, anode functional layer, and electrolyte of anode-supported SOFCs are produced using this technique. The performance of SOFCs produced this way is not yet equal to that of traditionally processed cells, but shows the promise of this technique.

Recent progress and future directions in protein-protein docking.

PubMed

Ritchie, David W

2008-02-01

This article gives an overview of recent progress in protein-protein docking and it identifies several directions for future research. Recent results from the CAPRI blind docking experiments show that docking algorithms are steadily improving in both reliability and accuracy. Current docking algorithms employ a range of efficient search and scoring strategies, including e.g. fast Fourier transform correlations, geometric hashing, and Monte Carlo techniques. These approaches can often produce a relatively small list of up to a few thousand orientations, amongst which a near-native binding mode is often observed. However, despite the use of improved scoring functions which typically include models of desolvation, hydrophobicity, and electrostatics, current algorithms still have difficulty in identifying the correct solution from the list of false positives, or decoys. Nonetheless, significant progress is being made through better use of bioinformatics, biochemical, and biophysical information such as e.g. sequence conservation analysis, protein interaction databases, alanine scanning, and NMR residual dipolar coupling restraints to help identify key binding residues. Promising new approaches to incorporate models of protein flexibility during docking are being developed, including the use of molecular dynamics snapshots, rotameric and off-rotamer searches, internal coordinate mechanics, and principal component analysis based techniques. Some investigators now use explicit solvent models in their docking protocols. Many of these approaches can be computationally intensive, although new silicon chip technologies such as programmable graphics processor units are beginning to offer competitive alternatives to conventional high performance computer systems. As cryo-EM techniques improve apace, docking NMR and X-ray protein structures into low resolution EM density maps is helping to bridge the resolution gap between these complementary techniques. The use of symmetry and fragment assembly constraints are also helping to make possible docking-based predictions of large multimeric protein complexes. In the near future, the closer integration of docking algorithms with protein interface prediction software, structural databases, and sequence analysis techniques should help produce better predictions of protein interaction networks and more accurate structural models of the fundamental molecular interactions within the cell.

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.

Methods for magnetic resonance analysis using magic angle technique

DOEpatents

Hu, Jian Zhi [Richland, WA; Wind, Robert A [Kennewick, WA; Minard, Kevin R [Kennewick, WA; Majors, Paul D [Kennewick, WA

2011-11-22

Methods of performing a magnetic resonance analysis of a biological object are disclosed that include placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. In particular embodiments the method includes pulsing the radio frequency to provide at least two of a spatially selective read pulse, a spatially selective phase pulse, and a spatially selective storage pulse. Further disclosed methods provide pulse sequences that provide extended imaging capabilities, such as chemical shift imaging or multiple-voxel data acquisition.

Neurosciences research in space - Future directions

NASA Technical Reports Server (NTRS)

Sulzman, Frank M.; Wolfe, James W.

1991-01-01

In order to gain a better understanding of the effects of long-duration space missions on the central nervous system, near-term research, to take place from 1990-1995, will be directed at investigating the acute effects of microgravity and the 'space adaptation syndrome'. These include experiments scheduled for the Spacelab Life Sciences 1 which is designed to evaluate changes in the visual, vestibular, and proprioceptive systems. An extensive series of experiments, collectively termed Microgravity Vestibular Investigations (MVI), is also planned for the IML-1 mission to be flown in 1992. The IML-2 mission will emphasize behavior and performance, biological rhythms, and further vestibular studies. Mid-term goals, projected to be achieved from 1995-2000, include the use of new technology such as magnetic recording techniques. Long-term goals are also discussed including studies dealing with neuronal plasticity and sensory substitution, augmentation, and robotic telepresence.

Feasibility Study of a Rotorcraft Health and Usage Monitoring System ( HUMS): Usage and Structural Life Monitoring Evaluation

NASA Technical Reports Server (NTRS)

Dickson, B.; Cronkhite, J.; Bielefeld, S.; Killian, L.; Hayden, R.

1996-01-01

The objective of this study was to evaluate two techniques, Flight Condition Recognition (FCR) and Flight Load Synthesis (FLS), for usage monitoring and assess the potential benefits of extending the retirement intervals of life-limited components, thus reducing the operator's maintenance and replacement costs. Both techniques involve indirect determination of loads using measured flight parameters and subsequent fatigue analysis to calculate the life expended on the life-limited components. To assess the potential benefit of usage monitoring, the two usage techniques were compared to current methods of component retirement. In addition, comparisons were made with direct load measurements to assess the accuracy of the two techniques. The data that was used for the evaluation of the usage monitoring techniques was collected under an independent HUMS Flight trial program, using a commercially available HUMS and data recording system. The usage data collect from the HUMS trial aircraft was analyzed off-line using PC-based software that included the FCR and FLS techniques. In the future, if the technique prove feasible, usage monitoring would be incorporated into the onboard HUMS.

ExoSOFT: Exoplanet Simple Orbit Fitting Toolbox

NASA Astrophysics Data System (ADS)

Mede, Kyle; Brandt, Timothy D.

2017-08-01

ExoSOFT provides orbital analysis of exoplanets and binary star systems. It fits any combination of astrometric and radial velocity data, and offers four parameter space exploration techniques, including MCMC. It is packaged with an automated set of post-processing and plotting routines to summarize results, and is suitable for performing orbital analysis during surveys with new radial velocity and direct imaging instruments.

Variable Selection Strategies for Small-area Estimation Using FIA Plots and Remotely Sensed Data

Treesearch

Andrew Lister; Rachel Riemann; James Westfall; Mike Hoppus

2005-01-01

The USDA Forest Service's Forest Inventory and Analysis (FIA) unit maintains a network of tens of thousands of georeferenced forest inventory plots distributed across the United States. Data collected on these plots include direct measurements of tree diameter and height and other variables. We present a technique by which FIA plot data and coregistered...

Medium Caliber Lead-Free Electric Primer. Version 2

DTIC Science & Technology

2012-09-01

Toxic Substance Control Act TGA Thermogravimetric Analysis TNR Trinitroresorcinol V Voltage VDC Voltage Direct Current WSESRB Weapons System...variety of techniques including Thermogravimetric Analysis (TGA), base-hydrolysis, Surface Area Analysis using Brunauer, Emmett, Teller (BET...Distribution From Thermogravimetric Analysis Johnson, C. E.; Fallis, S.; Chafin, A. P.; Groshens, T. J.; Higa, K. T.; Ismail, I. M. K. and Hawkins, T. W

Noise model for low-frequency through-the-Earth communication

NASA Astrophysics Data System (ADS)

Raab, Frederick H.

2010-12-01

Analysis and simulation of through-the-Earth communication links and signal processing techniques require a more complete noise model than is needed for the analysis of conventional communication systems. This paper presents a multicomponent noise model that includes impulsive characteristics, direction-of-arrival characteristics, and effects of local geology. The noise model is derived from theoretical considerations and confirmed by field tests.

Space-Based Counterforce in the Second Nuclear Age

DTIC Science & Technology

2015-04-01

nuclear counterforce missiles and anti-ICBM missiles and mines ], equipped with the complete spectrum of sensing equipment including infrared...yield, fallout minimized nuclear weapons. Each ship would also have a robust loadout of space mines and anti-ICBM missiles or directed energy...29 incoming asteroids or comets which could impact Earth carrying whatever deflection technique deemed appropriate to the threat, potentially

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

Dmitriev, Alexander S.; Yemelyanov, Ruslan Yu.; Moscow Institute of Physics and Technology

The paper deals with a new multi-element processor platform assigned for modelling the behaviour of interacting dynamical systems, i.e., active wireless network. Experimentally, this ensemble is implemented in an active network, the active nodes of which include direct chaotic transceivers and special actuator boards containing microcontrollers for modelling the dynamical systems and an information display unit (colored LEDs). The modelling technique and experimental results are described and analyzed.

Eukaryotic Chemotaxis

PubMed Central

Rappel, Wouter-Jan; Loomis, William F.

2009-01-01

During eukaryotic chemotaxis, external chemical gradients guide the crawling motion of cells. This process plays an important role in a large variety of biological systems and has wide ranging medical implications. New experimental techniques including confocal microscopy and microfluidics have advanced our understanding of chemotaxis while numerical modeling efforts are beginning to offer critical insights. In this short review, we survey the current experimental status of the field by dividing chemotaxis into three distinct “modules”: directional sensing, polarity and motility. For each module, we attempt to point out potential new directions of research and discuss how modeling studies interact with experimental investigations. PMID:20648241

Imaging angiogenesis.

PubMed

Charnley, Natalie; Donaldson, Stephanie; Price, Pat

2009-01-01

There is a need for direct imaging of effects on tumor vasculature in assessment of response to antiangiogenic drugs and vascular disrupting agents. Imaging tumor vasculature depends on differences in permeability of vasculature of tumor and normal tissue, which cause changes in penetration of contrast agents. Angiogenesis imaging may be defined in terms of measurement of tumor perfusion and direct imaging of the molecules involved in angiogenesis. In addition, assessment of tumor hypoxia will give an indication of tumor vasculature. The range of imaging techniques available for these processes includes positron emission tomography (PET), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), perfusion computed tomography (CT), and ultrasound (US).

Direct profiling of phytochemicals in tulip tissues and in vivo monitoring of the change of carbohydrate content in tulip bulbs by probe electrospray ionization mass spectrometry.

PubMed

Yu, Zhan; Chen, Lee Chuin; Suzuki, Hiroaki; Ariyada, Osamu; Erra-Balsells, Rosa; Nonami, Hiroshi; Hiraoka, Kenzo

2009-12-01

Probe electrospray ionization (PESI) is a recently developed ESI-based ionization technique which generates electrospray from the tip of a solid needle. In this study, we have applied PESI interfaced with a time of flight mass spectrometer (TOF-MS) for direct profiling of phytochemicals in a section of a tulip bulb in different regions, including basal plate, outer and inner rims of scale, flower bud and foliage leaves. Different parts of tulip petals and leaves have also been investigated. Carbohydrates, amino acids and other phytochemicals were detected. A series of in vivo PESI-MS experiments were carried out on the second outermost scales of four living tulip bulbs to monitoring the change of carbohydrate content during the first week of initial growth. The breakdown of carbohydrates was observed which was in accordance with previous reports achieved by other techniques. This study has indicated that PESI-MS can be used for rapid and direct analysis of phytochemicals in living biological systems with advantages of low sample consumption and little sample preparation. Therefore, PESI-MS can be a new choice for direct analysis/profiling of bioactive compounds or monitoring metabolic changes in living biological systems.

Plasma shield lasertripsy: in vitro studies.

PubMed

Bhatta, K M; Rosen, D I; Dretler, S P

1989-10-01

A technique for safer and more effective pulsed laser lithotripsy of urinary and biliary calculi was investigated in vitro. The technique involves enclosing the distal end of the laser delivery fiber in a "plasma shield." The plasma shield is a specially designed metal cap that serves to transfer the laser-induced mechanical impulse to the calculus while shielding surrounding tissue from direct laser exposure and thermal radiation. The metal cap also offers the advantage of effectively blunting the sharp fiber tip and improving its visualization under fluoroscopy. Plasma shield lithotripsy using a 200 micron quartz fiber inserted into a section of a modified 0.034 in. diameter stainless steel guide wire was tested in vitro on a variety of calculi and compared with results obtained using a 200 micron laser fiber applied directly. Calculi tested included cystine, struvite and calcium oxalate dihydrate urinary stones and pigmented cholesterol gallstones. The laser source was a flashlamp-pumped dye laser producing pulses of 1.2 microsecond duration and operated at a wavelength of 504 nm and pulse repetition frequency of 5 Hz. The results show that plasma shield lasertripsy is as effective as direct lasertripsy for fragmenting gallstones, struvite and calcium oxalate dihydrate calculi, is potentially safer, and can fragment cystine calculi which the pulsed dye laser applied directly cannot.

Transcranial Direct Current Stimulation in Child and Adolescent Psychiatry.

PubMed

Muszkat, Débora; Polanczyk, Guilherme Vanoni; Dias, Taciana G Costa; Brunoni, André Russowsky

2016-09-01

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that consists of applying a weak electric current over the scalp to modulate cortical excitability. tDCS has been extensively investigated in adults with psychiatric disorders. The aim of this study was to review the current literature regarding the use of tDCS in children and adolescents with psychiatric disorders. We searched MEDLINE and EMBASE databases for studies evaluating the safety and efficacy of tDCS in children and adolescents from age 0 to 18 years with psychiatric disorders. We found six studies that evaluated patients with different psychiatric disorders, with diverse study designs and stimulation parameters, including three small randomized clinical trials (RCTs), one evaluating childhood-onset schizophrenia, one RCT with patients with autism spectrum disorders (ASD), and one study in attention-deficit/hyperactivity disorder (ADHD); three open-label studies, two evaluating patients with ASD, and one study of feasibility of the technique in children and adolescents with language disorders and diverse psychiatric disorders, including ASD, intellectual disability, and ADHD. We also found three studies of dosage considerations in the general pediatric population. The technique was well tolerated, with no reports of serious side effects. Preliminary research suggests that tDCS may be well tolerated and safe for children and adolescents with psychiatric and neurodevelopmental disorders. Nevertheless, because the literature regarding tDCS in child and adolescent psychiatry is scarce and there exist limited numbers of randomized controlled trials, it is not possible to draw definite conclusions. Future studies should investigate the technique with regard to specific psychiatric conditions in comparison with standard treatments. In addition, long-term efficacy and safety should be monitored.

Definition of fields margins for palliative radiotherapy of pancreatic carcinoma.

PubMed

Buwenge, Milly; Marinelli, Alfonso; Deodato, Francesco; Macchia, Gabriella; Wondemagegnhu, Tigeneh; Salah, Tareq; Cammelli, Silvia; Uddin, A F M Kamal; Sumon, Mostafa A; Donati, Constanza M; Cilla, Savino; Morganti, Alessio G

2018-06-01

The present study aimed to provide practical guidelines for palliative treatment of advanced carcinoma of the pancreas (CAP) with the 2D technique. Fifteen patients with locally advanced CAP consecutively treated with radiation therapy at the Radiation Oncology Center, Research and Care Foundation 'Giovanni Paolo II' (Campobasso, Italy) underwent computed tomography simulation in supine position. Definition of the clinical target volume (CTV) included the head and body of the pancreas, and the retropancreatic space. The planning target volume was defined by adding a margin of 14 mm to the CTV in the cranio-caudal direction and of 11 mm in radial direction. For each patient, 3 treatment plans were calculated using a cobalt source, 6 MV photons and 15 MV photons (box technique). Beams were drawn using the primary collimators without using multileaf collimators, and progressively optimized in order to respect the minimum dose (D min >90%) constraint. Once the final plan was achieved, distances of the fields edges from a set of reference points (bony or duodenal landmarks) were measured. Using this technique, 15 anterior-posterior and postero-anterior (AP-PA) beams and 15 pairs of lateral-lateral (LL) beams were defined for the different patients. Finally, the single minimal AP-PA and LL beams able to include the 15 sets of AP-PA and LL beams were defined. The results of this analysis are reported in tabular form. Guidelines are provided for treatment based on cobalt unit or Linear accelerator (both 6 and 15 MV photons). This study provides information regarding field size and position. A dosimetric study has been planned to identify the dose to be administered with this technique taking into account current dose-volume constraints.

A systematic review on the surgical outcome of preauricular sinus excision techniques.

PubMed

Bruijnzeel, Hanneke; van den Aardweg, Maaike T; Grolman, Wilko; Stegeman, Inge; van der Veen, Erwin L

2016-07-01

Preauricular sinuses are benign congenital malformations of preauricular soft tissues. Complete excision using either sinectomy or supra-auricular approach is advised to prevent recurrence. Reported recurrence varies between 0 and 42%. We evaluated which surgical technique resulted in lowest complication and recurrence rates. PubMed, Embase, Scopus, Web of Science. Two authors appraised studies on directness of evidence and risk of bias. Original data were extracted and pooled when I(2) was smaller than 50%. Results are reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Fourteen high directness of evidence studies were included. Reported complication rates were similar: sinectomy [0-31.4%] and supra-auricular approach (SAA) [0-18.2%]. Pooled recurrence rates showed that sinectomy resulted in significantly (P = .04) more recurrence 5.5% (95% confidence interval [CI] 3.6-8.3%) than SAA 2.2% (95% CI 0.7-7.0). Sinectomy using the microscope resulted in the lowest sinectomy recurrence rates (1.9%). SAA in combination with a Penrose drain resulted in 0% recurrence in revision cases. Drain use resulted in the lowest SAA recurrence rates; however, drain application was not advised due to higher complication rates (frequent wound infection [P = .003] and more [P = .002] and longer [P = .001] compression dressing use). SAA could be the preferable technique for preauricular sinus removal. If despite evidence, sinectomy is elected over SAA, microscope use can further decrease recurrence rates comparable to SAA levels. Level of included evidence (Ib-IV) indicates the need for a prospective study comparing surgical outcomes between techniques. Laryngoscope, 126:1535-1544, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

The semantic differential in landscape research

Treesearch

H. E. Echelberger

1979-01-01

On-site reactions of groups of viewers to six timber harvesting procedures were measured by direct and indirect measuring techniques. Using the direct technique, groups recorded their overall impressions of harvested tracts on five-point scales ranging from very favorable to very unfavorable. For the indirect technique, semantic differential procedures were used....

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.

A technique to remove the tensile instability in weakly compressible SPH

NASA Astrophysics Data System (ADS)

Xu, Xiaoyang; Yu, Peng

2018-01-01

When smoothed particle hydrodynamics (SPH) is directly applied for the numerical simulations of transient viscoelastic free surface flows, a numerical problem called tensile instability arises. In this paper, we develop an optimized particle shifting technique to remove the tensile instability in SPH. The basic equations governing free surface flow of an Oldroyd-B fluid are considered, and approximated by an improved SPH scheme. This includes the implementations of the correction of kernel gradient and the introduction of Rusanov flux into the continuity equation. To verify the effectiveness of the optimized particle shifting technique in removing the tensile instability, the impacting drop, the injection molding of a C-shaped cavity, and the extrudate swell, are conducted. The numerical results obtained are compared with those simulated by other numerical methods. A comparison among different numerical techniques (e.g., the artificial stress) to remove the tensile instability is further performed. All numerical results agree well with the available data.

Single-mode fiber, velocity interferometry

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

Krauter, K. G.; Jacobson, G. F.; Patterson, J. R.

2011-04-15

In this paper, we describe a velocity interferometer system based entirely on single-mode fiber optics. This paper includes a description of principles used in developing the single-mode velocity interferometry system (SMV). The SMV design is based on polarization-insensitive components. Polarization adjusters are included to eliminate the effects of residual birefringence and polarization dependent losses in the interferometers. Characterization measurements and calibration methods needed for data analysis and a method of data analysis are described. Calibration is performed directly using tunable lasers. During development, we demonstrated its operation using exploding-foil bridge-wire fliers up to 200 m/s. In a final test, wemore » demonstrated the SMV in a gas gun experiment up to 1.2 km/sec. As a basis for comparison in the gas gun experiment, we used another velocimetry technique that is also based on single-mode fiber optics: photonic Doppler velocimetry (PDV). For the gas gun experiment, we split the light returned from a single target spot and performed a direct comparison of the homodyne (SMV) and heterodyne (PDV) techniques concurrently. The two techniques had a negligible mean difference and a 1.5% standard deviation in the one-dimensional shock zone. Within one interferometer delay time after a sudden Doppler shift, a SMV unencumbered by multimode-fiber dispersion exhibits two color beats. These beats have the same period as PDV beats--this interference occurs between the ''recently'' shifted and ''formerly unshifted'' paths within the interferometer. We believe that recognizing this identity between homodyne and heterodyne beats is novel in the shock-physics field. SMV includes the conveniences of optical fiber, while removing the time resolution limitations associated with the multimode delivery fiber.« less

Single-mode fiber, velocity interferometry.

PubMed

Krauter, K G; Jacobson, G F; Patterson, J R; Nguyen, J H; Ambrose, W P

2011-04-01

In this paper, we describe a velocity interferometer system based entirely on single-mode fiber optics. This paper includes a description of principles used in developing the single-mode velocity interferometry system (SMV). The SMV design is based on polarization-insensitive components. Polarization adjusters are included to eliminate the effects of residual birefringence and polarization dependent losses in the interferometers. Characterization measurements and calibration methods needed for data analysis and a method of data analysis are described. Calibration is performed directly using tunable lasers. During development, we demonstrated its operation using exploding-foil bridge-wire fliers up to 200 m/s. In a final test, we demonstrated the SMV in a gas gun experiment up to 1.2 km/sec. As a basis for comparison in the gas gun experiment, we used another velocimetry technique that is also based on single-mode fiber optics: photonic Doppler velocimetry (PDV). For the gas gun experiment, we split the light returned from a single target spot and performed a direct comparison of the homodyne (SMV) and heterodyne (PDV) techniques concurrently. The two techniques had a negligible mean difference and a 1.5% standard deviation in the one-dimensional shock zone. Within one interferometer delay time after a sudden Doppler shift, a SMV unencumbered by multimode-fiber dispersion exhibits two color beats. These beats have the same period as PDV beats-this interference occurs between the "recently" shifted and "formerly unshifted" paths within the interferometer. We believe that recognizing this identity between homodyne and heterodyne beats is novel in the shock-physics field. SMV includes the conveniences of optical fiber, while removing the time resolution limitations associated with the multimode delivery fiber. © 2011 American Institute of Physics

Medicines Information and the Regulation of the Promotion of Pharmaceuticals.

PubMed

Leonardo Alves, Teresa; Lexchin, Joel; Mintzes, Barbara

2018-05-02

Many factors contribute to the inappropriate use of medicines, including not only a lack of information but also inaccurate and misleading promotional information. This review examines how the promotion of pharmaceuticals directly affects the prescribing and use of medicines. We define promotion broadly as all actions taken directly by pharmaceutical companies with the aim of enhancing product sales. We look in greater detail at promotion techniques aimed at prescribers, such as sales representatives, pharmaceutical advertisements in medical journals and use of key opinion leaders, along with the quality of information provided and the effects thereof. We also discuss promotion to the public, through direct-to-consumer advertising, and its effects. Finally, we consider initiatives to regulate promotion that come from industry, government and nongovernmental organizations.

1H MAS NMR (magic-angle spinning nuclear magnetic resonance) techniques for the quantitative determination of hydrogen types in solid catalysts and supports.

PubMed

Kennedy, Gordon J; Afeworki, Mobae; Calabro, David C; Chase, Clarence E; Smiley, Randolph J

2004-06-01

Distinct hydrogen species are present in important inorganic solids such as zeolites, silicoaluminophosphates (SAPOs), mesoporous materials, amorphous silicas, and aluminas. These H species include hydrogens associated with acidic sites such as Al(OH)Si, non-framework aluminum sites, silanols, and surface functionalities. Direct and quantitative methodology to identify, measure, and monitor these hydrogen species are key to monitoring catalyst activity, optimizing synthesis conditions, tracking post-synthesis structural modifications, and in the preparation of novel catalytic materials. Many workers have developed several techniques to address these issues, including 1H MAS NMR (magic-angle spinning nuclear magnetic resonance). 1H MAS NMR offers many potential advantages over other techniques, but care is needed in recognizing experimental limitations and developing sample handling and NMR methodology to obtain quantitatively reliable data. A simplified approach is described that permits vacuum dehydration of multiple samples simultaneously and directly in the MAS rotor without the need for epoxy, flame sealing, or extensive glovebox use. We have found that careful optimization of important NMR conditions, such as magnetic field homogeneity and magic angle setting are necessary to acquire quantitative, high-resolution spectra that accurately measure the concentrations of the different hydrogen species present. Details of this 1H MAS NMR methodology with representative applications to zeolites, SAPOs, M41S, and silicas as a function of synthesis conditions and post-synthesis treatments (i.e., steaming, thermal dehydroxylation, and functionalization) are presented.

Low frequency ultrasonic nondestructive inspection of aluminum/adhesive fuselage lap splices

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

Patton, Thadd

1994-01-04

This thesis is a collection of research efforts in ultrasonics, conducted at the Center for Aviation Systems Reliability located at Iowa State University, as part of the Federal Aviation Administration`s ``Aging Aircraft Program.`` The research was directed toward the development of an ultrasonic prototype to inspect the aluminum/adhesive fuselage lap splices found on 1970`s vintage Boeing passenger aircraft. The ultrasonic prototype consists of a normal incidence, low frequency inspection technique, and a scanning adapter that allows focused immersion transducers to be operated in a direct contact manner in any inspection orientation, including upside-down. The inspection technique uses a computer-controlled datamore » acquisition system to produce a C-scan image of a radio frequency (RF) waveform created by a low frequency, broadband, focused beam transducer, driven with a spike voltage pulser. C-scans produced by this technique are color representations of the received signal`s peak-to-peak amplitude (voltage) taken over an (x, y) grid. Low frequency, in this context, refers to a wavelength that is greater than the lap splice`s layer thicknesses. With the low frequency technique, interface echoes of the lap splice are not resolved and gating of the signal is unnecessary; this in itself makes the technique simple to implement and saves considerable time in data acquisition. Along with the advantages in data acquisition, the low frequency technique is relatively insensitive to minor surface curvature and to ultrasonic interference effects caused by adhesive bondline thickness variations in the lap splice.« less

Determining wave direction using curvature parameters.

PubMed

de Queiroz, Eduardo Vitarelli; de Carvalho, João Luiz Baptista

2016-01-01

The curvature of the sea wave was tested as a parameter for estimating wave direction in the search for better results in estimates of wave direction in shallow waters, where waves of different sizes, frequencies and directions intersect and it is difficult to characterize. We used numerical simulations of the sea surface to determine wave direction calculated from the curvature of the waves. Using 1000 numerical simulations, the statistical variability of the wave direction was determined. The results showed good performance by the curvature parameter for estimating wave direction. Accuracy in the estimates was improved by including wave slope parameters in addition to curvature. The results indicate that the curvature is a promising technique to estimate wave directions.•In this study, the accuracy and precision of curvature parameters to measure wave direction are analyzed using a model simulation that generates 1000 wave records with directional resolution.•The model allows the simultaneous simulation of time-series wave properties such as sea surface elevation, slope and curvature and they were used to analyze the variability of estimated directions.•The simultaneous acquisition of slope and curvature parameters can contribute to estimates wave direction, thus increasing accuracy and precision of results.

Even an old technique is suitable in the molecular world of science: the everted sac preparation turns 60 years old.

PubMed

Hamilton, Kirk L

2014-04-15

An old proverb states "necessity is the mother of invention." This certainly holds true in science as one pursues research questions. Experimental techniques have evolved as scientists have asked more specific research questions. Indeed, techniques such as the Ussing chamber, the perfused renal tubule preparation, patch-clamp, polymerase chain reaction, and site-directed mutagenesis have been developed over the past 60 years. However, sometimes, simple techniques may be useful and still very informative, and this certainly applies to intestinal physiology. Indeed, Gerald Wiseman and Thomas Hastings Wilson described the intestinal everted sac preparation some 60 years ago. Since then, this technique has been used for numerous research purposes including determining ion, amino acid, water and solute transport across the intestinal epithelium; and drug metabolism, absorption, and interactions in pharmaceutical/pharmacological research and even in education. This article provides a historical review of the development of the in vitro intestinal preparation that led to the everted sac preparation and its use in science.

Implementation of magnetic resonance elastography for the investigation of traumatic brain injuries

NASA Astrophysics Data System (ADS)

Boulet, Thomas

Magnetic resonance elastography (MRE) is a potentially transformative imaging modality allowing local and non-invasive measurement of biological tissue mechanical properties. It uses a specific phase contrast MR pulse sequence to measure induced vibratory motion in soft material, from which material properties can be estimated. Compared to other imaging techniques, MRE is able to detect tissue pathology at early stages by quantifying the changes in tissue stiffness associated with diseases. In an effort to develop the technique and improve its capabilities, two inversion algorithms were written to evaluate viscoelastic properties from the measured displacements fields. The first one was based on a direct algebraic inversion of the differential equation of motion, which decouples under certain simplifying assumptions, and featured a spatio-temporal multi-directional filter. The second one relies on a finite element discretization of the governing equations to perform a direct inversion. Several applications of this technique have also been investigated, including the estimation of mechanical parameters in various gel phantoms and polymers, as well as the use of MRE as a diagnostic tools for brain disorders. In this respect, the particular interest was to investigate traumatic brain injury (TBI), a complex and diverse injury affecting 1.7 million Americans annually. The sensitivity of MRE to TBI was first assessed on excised rat brains subjected to a controlled cortical impact (CCI) injury, before execution of in vivo experiments in mice. MRE was also applied in vivo on mouse models of medulloblastoma tumors and multiple sclerosis. These studies showed the potential of MRE in mapping the brain mechanically and providing non-invasive in vivo imaging markers for neuropathology and pathogenesis of brain diseases. Furthermore, MRE can easily be translatable to clinical settings; thus, while this technique may not be used directly to diagnose different abnormalities in the brain at this time, it may be helpful to detect abnormalities, follow therapies, and trace macroscopic changes that are not seen by conventional methods with clinical relevance.

How to use the nominal group and Delphi techniques.

PubMed

McMillan, Sara S; King, Michelle; Tully, Mary P

2016-06-01

Introduction The Nominal Group Technique (NGT) and Delphi Technique are consensus methods used in research that is directed at problem-solving, idea-generation, or determining priorities. While consensus methods are commonly used in health services literature, few studies in pharmacy practice use these methods. This paper provides an overview of the NGT and Delphi technique, including the steps involved and the types of research questions best suited to each method, with examples from the pharmacy literature. Methodology The NGT entails face-to-face discussion in small groups, and provides a prompt result for researchers. The classic NGT involves four key stages: silent generation, round robin, clarification and voting (ranking). Variations have occurred in relation to generating ideas, and how 'consensus' is obtained from participants. The Delphi technique uses a multistage self-completed questionnaire with individual feedback, to determine consensus from a larger group of 'experts.' Questionnaires have been mailed, or more recently, e-mailed to participants. When to use The NGT has been used to explore consumer and stakeholder views, while the Delphi technique is commonly used to develop guidelines with health professionals. Method choice is influenced by various factors, including the research question, the perception of consensus required, and associated practicalities such as time and geography. Limitations The NGT requires participants to personally attend a meeting. This may prove difficult to organise and geography may limit attendance. The Delphi technique can take weeks or months to conclude, especially if multiple rounds are required, and may be complex for lay people to complete.

A cost comparison analysis of adjuvant radiation therapy techniques after breast-conserving surgery.

PubMed

Lanni, Thomas; Keisch, Martin; Shah, Chirag; Wobb, Jessica; Kestin, Larry; Vicini, Frank

2013-01-01

The aim of this study is to perform a cost analysis to compare adjuvant radiation therapy schedules following breast conserving surgery. Treatment planning and delivery utilization data were modeled for a series of 10 different breast RT techniques. The whole breast (WB) regimens consisted of: (1) Wedge based WB (25 fractions [fx]), (2) WB using IMRT, (3) WBRT with a boost (B), (4) WBRT using IMRT with a B, (5) Canadian WB (16 fx) with 3D-CRT, and (6) Canadian using IMRT. The accelerated partial breast irradiation (APBI) regimens included (7): APBI using 3D-CRT, (8) IMRT, (9) single channel balloon, and (10) multi-channel balloon. Costs incurred by the payer (i.e., direct medical costs) were taken from the 2011 Medicare Fee Schedule. Among all the different regimens examined, Canadian 3D-CRT and APBI 3D-CRT were the least costly whereas WB using IMRT with a B was the most expensive. Both APBI brachytherapy techniques were less costly than conventional WB with a B. In terms of direct medical costs, the technical component accounted for most, if not all, of the disparity among the various treatments. A general trend of decreasing RT costs was observed with further reductions in overall treatment time for WBRT techniques, but not all of the alternative treatment regimens led to similar total cost savings. APBI using brachytherapy techniques was less costly than conventional WBRT with a standard boost. © 2013 Wiley Periodicals, Inc.

Ex vivo confocal microscopy: an emerging technique in dermatology

PubMed Central

Perrot, Jean Luc; Labeille, Bruno; Cambazard, Frédéric; Rubegni, Pietro

2018-01-01

This review aims to give an overview of the current available applications of ex vivo confocal microscopy (EVCM) in dermatology. EVCM is a relatively new imaging technique that allows microscopic examination of freshly excised unfixed tissue. It enables a rapid examination of the skin sample directly in the surgery room and thus represents an alternative to the intraoperative micrographic control of the surgical margins of cutaneous tumors by standard microscopic examination on cryopreserved sections during Mohs surgery. Although this technique has mainly been developed for the margin’s control of basal cell carcinoma, many other skin tumors have been studied, including melanoma. Use of EVCM is continuing to evolve, and many possible applications are under investigation, such as the study of nails and hair diseases and the diagnosis of skin infections. PMID:29785327

Development of a real-time aeroperformance analysis technique for the X-29A advanced technology demonstrator

NASA Technical Reports Server (NTRS)

Ray, R. J.; Hicks, J. W.; Alexander, R. I.

1988-01-01

The X-29A advanced technology demonstrator has shown the practicality and advantages of the capability to compute and display, in real time, aeroperformance flight results. This capability includes the calculation of the in-flight measured drag polar, lift curve, and aircraft specific excess power. From these elements many other types of aeroperformance measurements can be computed and analyzed. The technique can be used to give an immediate postmaneuver assessment of data quality and maneuver technique, thus increasing the productivity of a flight program. A key element of this new method was the concurrent development of a real-time in-flight net thrust algorithm, based on the simplified gross thrust method. This net thrust algorithm allows for the direct calculation of total aircraft drag.

3D Sound Techniques for Sound Source Elevation in a Loudspeaker Listening Environment

NASA Astrophysics Data System (ADS)

Kim, Yong Guk; Jo, Sungdong; Kim, Hong Kook; Jang, Sei-Jin; Lee, Seok-Pil

In this paper, we propose several 3D sound techniques for sound source elevation in stereo loudspeaker listening environments. The proposed method integrates a head-related transfer function (HRTF) for sound positioning and early reflection for adding reverberant circumstance. In addition, spectral notch filtering and directional band boosting techniques are also included for increasing elevation perception capability. In order to evaluate the elevation performance of the proposed method, subjective listening tests are conducted using several kinds of sound sources such as white noise, sound effects, speech, and music samples. It is shown from the tests that the degrees of perceived elevation by the proposed method are around the 17º to 21º when the stereo loudspeakers are located on the horizontal plane.

Networked Airborne Communications Using Adaptive Multi Beam Directional Links

DTIC Science & Technology

2016-03-05

Networked Airborne Communications Using Adaptive Multi-Beam Directional Links R. Bruce MacLeod Member, IEEE, and Adam Margetts Member, IEEE MIT...provide new techniques for increasing throughput in airborne adaptive directional net- works. By adaptive directional linking, we mean systems that can...techniques can dramatically increase the capacity in airborne networks. Advances in digital array technology are beginning to put these gains within reach

Spermatogonial stem cell transplantation and male infertility: Current status and future directions.

PubMed

Forbes, Connor M; Flannigan, Ryan; Schlegel, Peter N

2018-03-01

To summarise the current state of research into spermatogonial stem cell (SSC) therapies with a focus on future directions, as SSCs show promise as a source for preserving or initiating fertility in otherwise infertile men. We performed a search for publications addressing spermatogonial stem cell transplantation in the treatment of male infertility. The search engines PubMed and Google Scholar were used from 1990 to 2017. Search terms were relevant for spermatogonial stem cell therapies. Titles of publications were screened for relevance; abstracts were read, if related and full papers were reviewed for directly pertinent original research. In all, 58 papers were found to be relevant to this review, and were included in appropriate subheadings. This review discusses the various techniques that SSCs are being investigated to treat forms of male infertility. Evidence does not yet support clinical application of SSCs in humans. However, significant progress in the in vitro and in vivo development of SSCs, including differentiation into functional germ cells, gives reason for cautious optimism for future research.

A comparative In vivo efficacy of three spiral techniques versus incremental technique in obturating primary teeth.

PubMed

Chandrasekhar, Shalini; Prasad, Madu Ghanashyam; Radhakrishna, Ambati Naga; Saujanya, Kaniti; Raviteja, N V K; Deepthi, B; Ramakrishna, J

2018-01-01

The aim of this study was to evaluate the efficiency of four different obturating techniques in filling the radicular space in primary teeth. This clinical trial was carried out on 34 healthy, cooperative children (5-9 years) who had 63 carious primary teeth indicated for pulpectomy. They were divided into four groups, such that in each group, a total of 40 canals were allotted for obturation with respective technique. The root canals of selected primary teeth were filled with Endoflas obturating material using either bi-directional spiral (Group 1); incremental technique (Group 2), past inject (Group 3) or lentulo spiral (Group 4) according to the groups assigned. The effectiveness of the obturation techniques was assessed using postoperative radiographs. The assessment was made for a depth of fill in the canal, the presence of any voids using Modified Coll and Sadrian criteria. The obtained data were analyzed by using ANOVA test and unpaired t-test. Bi-directional spiral and lentulo spiral were superior to other techniques in providing optimally filled canals (P< 0.05). The bi-directional spiral was superior to lentulo spiral in preventing overfill (P< 0.05). Based on the present study results, bi-directional spiral can be recommended as an alternate obturating technique in primary teeth.

Use of the learning conversation improves instructor confidence in life support training: An open randomised controlled cross-over trial comparing teaching feedback mechanisms.

PubMed

Baldwin, Lydia J L; Jones, Christopher M; Hulme, Jonathan; Owen, Andrew

2015-11-01

Feedback is vital for the effective delivery of skills-based education. We sought to compare the sandwich technique and learning conversation structured methods of feedback delivery in competency-based basic life support (BLS) training. Open randomised crossover study undertaken between October 2014 and March 2015 at the University of Birmingham, United Kingdom. Six-hundred and forty healthcare students undertaking a European Resuscitation Council (ERC) BLS course were enrolled, each of whom was randomised to receive teaching using either the sandwich technique or the learning conversation. Fifty-eight instructors were randomised to initially teach using either the learning conversation or sandwich technique, prior to crossing-over and teaching with the alternative technique after a pre-defined time period. Outcome measures included skill acquisition as measured by an end-of-course competency assessment, instructors' perception of teaching with each feedback technique and candidates' perception of the feedback they were provided with. Scores assigned to use of the learning conversation by instructors were significantly more favourable than for the sandwich technique across all but two assessed domains relating to instructor perception of the feedback technique, including all skills-based domains. No difference was seen in either assessment pass rates (80.9% sandwich technique vs. 77.2% learning conversation; OR 1.2, 95% CI 0.85-1.84; p=0.29) or any domain relating to candidates' perception of their teaching technique. This is the first direct comparison of two feedback techniques in clinical medical education using both quantitative and qualitative methodology. The learning conversation is preferred by instructors providing competency-based life support training and is perceived to favour skills acquisition. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Directional spectra of ocean waves from microwave backscatter: A physical optics solution with application to the short-pulse and two-frequency measurement techniques

NASA Technical Reports Server (NTRS)

Jackson, F. C.

1979-01-01

Two simple microwave radar techniques that are potentially capable of providing routine satellite measurements of the directional spectrum of ocean waves were developed. One technique, the short pulse technique, makes use of very short pulses to resolve ocean surface wave contrast features in the range direction; the other technique, the two frequency correlation technique makes use of coherency in the transmitted waveform to detect the large ocean wave contrast modulation as a beat or mixing frequency in the power backscattered at two closely separated microwave frequencies. A frequency domain analysis of the short pulse and two frequency systems shows that the two measurement systems are essentially duals; they each operate on the generalized (three frequency) fourth-order statistical moment of the surface transfer function in different, but symmetrical ways, and they both measure the same directional contrast modulation spectrum. A three dimensional physical optics solution for the fourth-order moment was obtained for backscatter in the near vertical, specular regime, assuming Gaussian surface statistics.

Extensions to decision curve analysis, a novel method for evaluating diagnostic tests, prediction models and molecular markers

PubMed Central

Vickers, Andrew J; Cronin, Angel M; Elkin, Elena B; Gonen, Mithat

2008-01-01

Background Decision curve analysis is a novel method for evaluating diagnostic tests, prediction models and molecular markers. It combines the mathematical simplicity of accuracy measures, such as sensitivity and specificity, with the clinical applicability of decision analytic approaches. Most critically, decision curve analysis can be applied directly to a data set, and does not require the sort of external data on costs, benefits and preferences typically required by traditional decision analytic techniques. Methods In this paper we present several extensions to decision curve analysis including correction for overfit, confidence intervals, application to censored data (including competing risk) and calculation of decision curves directly from predicted probabilities. All of these extensions are based on straightforward methods that have previously been described in the literature for application to analogous statistical techniques. Results Simulation studies showed that repeated 10-fold crossvalidation provided the best method for correcting a decision curve for overfit. The method for applying decision curves to censored data had little bias and coverage was excellent; for competing risk, decision curves were appropriately affected by the incidence of the competing risk and the association between the competing risk and the predictor of interest. Calculation of decision curves directly from predicted probabilities led to a smoothing of the decision curve. Conclusion Decision curve analysis can be easily extended to many of the applications common to performance measures for prediction models. Software to implement decision curve analysis is provided. PMID:19036144

Extensions to decision curve analysis, a novel method for evaluating diagnostic tests, prediction models and molecular markers.

PubMed

Vickers, Andrew J; Cronin, Angel M; Elkin, Elena B; Gonen, Mithat

2008-11-26

Decision curve analysis is a novel method for evaluating diagnostic tests, prediction models and molecular markers. It combines the mathematical simplicity of accuracy measures, such as sensitivity and specificity, with the clinical applicability of decision analytic approaches. Most critically, decision curve analysis can be applied directly to a data set, and does not require the sort of external data on costs, benefits and preferences typically required by traditional decision analytic techniques. In this paper we present several extensions to decision curve analysis including correction for overfit, confidence intervals, application to censored data (including competing risk) and calculation of decision curves directly from predicted probabilities. All of these extensions are based on straightforward methods that have previously been described in the literature for application to analogous statistical techniques. Simulation studies showed that repeated 10-fold crossvalidation provided the best method for correcting a decision curve for overfit. The method for applying decision curves to censored data had little bias and coverage was excellent; for competing risk, decision curves were appropriately affected by the incidence of the competing risk and the association between the competing risk and the predictor of interest. Calculation of decision curves directly from predicted probabilities led to a smoothing of the decision curve. Decision curve analysis can be easily extended to many of the applications common to performance measures for prediction models. Software to implement decision curve analysis is provided.

Cracking-assisted fabrication of nanoscale patterns for micro/nanotechnological applications

NASA Astrophysics Data System (ADS)

Kim, Minseok; Kim, Dong-Joo; Ha, Dogyeong; Kim, Taesung

2016-05-01

Cracks are frequently observed in daily life, but they are rarely welcome and are considered as a material failure mode. Interestingly, cracks cause critical problems in various micro/nanofabrication processes such as colloidal assembly, thin film deposition, and even standard photolithography because they are hard to avoid or control. However, increasing attention has been given recently to control and use cracks as a facile, low-cost strategy for producing highly ordered nanopatterns. Specifically, cracking is the breakage of molecular bonds and occurs simultaneously over a large area, enabling fabrication of nanoscale patterns at both high resolution and high throughput, which are difficult to obtain simultaneously using conventional nanofabrication techniques. In this review, we discuss various cracking-assisted nanofabrication techniques, referred to as crack lithography, and summarize the fabrication principles, procedures, and characteristics of the crack patterns such as their position, direction, and dimensions. First, we categorize crack lithography techniques into three technical development levels according to the directional freedom of the crack patterns: randomly oriented, unidirectional, or multidirectional. Then, we describe a wide range of novel practical devices fabricated by crack lithography, including bioassay platforms, nanofluidic devices, nanowire sensors, and even biomimetic mechanosensors.

Direct torsional actuation of microcantilevers using magnetic excitation

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

Gosvami, Nitya Nand; Nalam, Prathima C.; Tam, Qizhan

2014-09-01

Torsional mode dynamic force microscopy can be used for a wide range of studies including mapping lateral contact stiffness, torsional frequency or amplitude modulation imaging, and dynamic friction measurements of various materials. Piezo-actuation of the cantilever is commonly used, but it introduces spurious resonances, limiting the frequency range that can be sampled, and rendering the technique particularly difficult to apply in liquid medium where the cantilever oscillations are significantly damped. Here, we demonstrate a method that enables direct torsional actuation of cantilevers with high uniformity over wide frequency ranges by attaching a micrometer-scale magnetic bead on the back side ofmore » the cantilever. We show that when beads are magnetized along the width of the cantilever, efficient torsional actuation of the cantilevers can be achieved using a magnetic field produced from a solenoid placed underneath the sample. We demonstrate the capability of this technique by imaging atomic steps on graphite surfaces in tapping mode near the first torsional resonance of the cantilever in dodecane. The technique is also applied to map the variations in the lateral contact stiffness on the surface of graphite and polydiacetylene monolayers.« less

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.

Criterion Validity of Measures of Perceived Relative Harm of E-Cigarettes and Smokeless Tobacco Compared to Cigarettes

PubMed Central

Persoskie, Alexander; Nguyen, Anh B.; Kaufman, Annette R.; Tworek, Cindy

2017-01-01

Beliefs about the relative harmfulness of one product compared to another (perceived relative harm) are central to research and regulation concerning tobacco and nicotine-containing products, but techniques for measuring such beliefs vary widely. We compared the validity of direct and indirect measures of perceived harm of e-cigarettes and smokeless tobacco (SLT) compared to cigarettes. On direct measures, participants explicitly compare the harmfulness of each product. On indirect measures, participants rate the harmfulness of each product separately, and ratings are compared. The U.S. Health Information National Trends Survey (HINTS-FDA-2015; N=3738) included direct measures of perceived harm of e-cigarettes and SLT compared to cigarettes. Indirect measures were created by comparing ratings of harm from e-cigarettes, SLT, and cigarettes on 3-point scales. Logistic regressions tested validity by assessing whether direct and indirect measures were associated with criterion variables including: ever-trying e-cigarettes, ever-trying snus, and SLT use status. Compared to the indirect measures, the direct measures of harm were more consistently associated with criterion variables. On direct measures, 26% of adults rated e-cigarettes as less harmful than cigarettes, and 11% rated SLT as less harmful than cigarettes. Direct measures appear to provide valid information about individuals’ harm beliefs, which may be used to inform research and tobacco control policy. Further validation research is encouraged. PMID:28073035

Indocyanine green staining facilitates detection of bleb leakage during trabeculectomy.

PubMed

Okazaki, Teruhiko; Kiuchi, Takahiro; Kawana, Keisuke; Oshika, Tetsuro

2007-03-01

To report a new technique to visualize bleb leakage using indocyanine green (ICG) staining during trabeculectomy. The ICG solution was widely applied over the filtering bleb including the conjunctival wound before completion of trabeculectomy. This procedure was performed in 48 eyes of 44 consecutive patients undergoing trabeculectomy between December 2004 and October 2005. Without staining, bleb leakage was not identified by the direct observation under the operating microscope. ICG staining clearly visualized aqueous leakage from the bleb in 5 eyes (10.4%). The bleb leakage in these eyes was easily repaired with 10-0 nylon sutures, and no eyes, including these 5 cases, showed bleb leakage after surgery. There were no intraoperative and postoperative complications related to ICG application. The application of ICG during trabeculectomy is a simple and useful technique to facilitate detection and repair of the bleb leakage.

SSBRP User Operations Facility (UOF) Overview and Development Strategy

NASA Technical Reports Server (NTRS)

Picinich, Lou; Stone, Thom; Sun, Charles; Windrem, May; Givens, John J. (Technical Monitor)

1995-01-01

This paper will present the Space Station Biological Research Project (SSBRP) User Operations Facility (UOF) architecture and development strategy. A major element of the UOF at NASA Ames Research Center, the Communication and Data System (CDS) will be the primary focus of the discussions. CDS operational, telescience, security, and development objectives will be discussed along with CDS implementation strategy. The implementation strategy discussions will include: Object Oriented Analysis & Design, System & Software Prototyping, and Technology Utilization. A CDS design overview that includes: CDS Context Diagram, CDS Architecture, Object Models, Use Cases, and User Interfaces will also be presented. CDS development brings together "cutting edge" technologies and techniques such as: object oriented development, network security, multimedia networking, web-based data distribution, JAVA, and graphical user interfaces. Use of these "cutting edge" technologies and techniques translates directly to lower development and operations costs.

Pre-clinical characterization of tissue engineering constructs for bone and cartilage regeneration

PubMed Central

Trachtenberg, Jordan E.; Vo, Tiffany N.; Mikos, Antonios G.

2014-01-01

Pre-clinical animal models play a crucial role in the translation of biomedical technologies from the bench top to the bedside. However, there is a need for improved techniques to evaluate implanted biomaterials within the host, including consideration of the care and ethics associated with animal studies, as well as the evaluation of host tissue repair in a clinically relevant manner. This review discusses non-invasive, quantitative, and real-time techniques for evaluating host-materials interactions, quality and rate of neotissue formation, and functional outcomes of implanted biomaterials for bone and cartilage tissue engineering. Specifically, a comparison will be presented for pre-clinical animal models, histological scoring systems, and non-invasive imaging modalities. Additionally, novel technologies to track delivered cells and growth factors will be discussed, including methods to directly correlate their release with tissue growth. PMID:25319726

Pre-clinical characterization of tissue engineering constructs for bone and cartilage regeneration.

PubMed

Trachtenberg, Jordan E; Vo, Tiffany N; Mikos, Antonios G

2015-03-01

Pre-clinical animal models play a crucial role in the translation of biomedical technologies from the bench top to the bedside. However, there is a need for improved techniques to evaluate implanted biomaterials within the host, including consideration of the care and ethics associated with animal studies, as well as the evaluation of host tissue repair in a clinically relevant manner. This review discusses non-invasive, quantitative, and real-time techniques for evaluating host-materials interactions, quality and rate of neotissue formation, and functional outcomes of implanted biomaterials for bone and cartilage tissue engineering. Specifically, a comparison will be presented for pre-clinical animal models, histological scoring systems, and non-invasive imaging modalities. Additionally, novel technologies to track delivered cells and growth factors will be discussed, including methods to directly correlate their release with tissue growth.

Experience with novel technologies for direct measurement of atmospheric NO2

NASA Astrophysics Data System (ADS)

Hueglin, Christoph; Hundt, Morten; Mueller, Michael; Schwarzenbach, Beat; Tuzson, Bela; Emmenegger, Lukas

2017-04-01

Nitrogen dioxide (NO2) is an air pollutant that has a large impact on human health and ecosystems, and it plays a key role in the formation of ozone and secondary particulate matter. Consequently, legal limit values for NO2 are set in the EU and elsewhere, and atmospheric observation networks typically include NO2 in their measurement programmes. Atmospheric NO2 is principally measured by chemiluminescence detection, an indirect measurement technique that requires conversion of NO2 into nitrogen monoxide (NO) and finally calculation of NO2 from the difference between total nitrogen oxides (NOx) and NO. Consequently, NO2 measurements with the chemiluminescence method have a relatively high measurement uncertainty and can be biased depending on the selectivity of the applied NO2 conversion method. In the past years, technologies for direct and selective measurement of NO2 have become available, e.g. cavity attenuated phase shift spectroscopy (CAPS), cavity enhanced laser absorption spectroscopy and quantum cascade laser absorption spectrometry (QCLAS). These technologies offer clear advantages over the indirect chemiluminescence method. We tested the above mentioned direct measurement techniques for NO2 over extended time periods at atmospheric measurement stations and report on our experience including comparisons with co-located chemiluminescence instruments equipped with molybdenum as well as photolytic NO2 converters. A still open issue related to the direct measurement of NO2 is instrument calibration. Accurate and traceable reference standards and NO2 calibration gases are needed. We present results from the application of different calibration strategies based on the use of static NO2 calibration gases as well as dynamic NO2 calibration gases produced by permeation and by gas-phase titration (GPT).

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.

Flight-vehicle materials, structures, and dynamics - Assessment and future directions. Vol. 5 - Structural dynamics and aeroelasticity

NASA Technical Reports Server (NTRS)

Noor, Ahmed K. (Editor); Venneri, Samuel L. (Editor)

1993-01-01

Various papers on flight vehicle materials, structures, and dynamics are presented. Individual topics addressed include: general modeling methods, component modeling techniques, time-domain computational techniques, dynamics of articulated structures, structural dynamics in rotating systems, structural dynamics in rotorcraft, damping in structures, structural acoustics, structural design for control, structural modeling for control, control strategies for structures, system identification, overall assessment of needs and benefits in structural dynamics and controlled structures. Also discussed are: experimental aeroelasticity in wind tunnels, aeroservoelasticity, nonlinear aeroelasticity, aeroelasticity problems in turbomachines, rotary-wing aeroelasticity with application to VTOL vehicles, computational aeroelasticity, structural dynamic testing and instrumentation.

Audio-Visual Situational Awareness for General Aviation Pilots

NASA Technical Reports Server (NTRS)

Spirkovska, Lilly; Lodha, Suresh K.; Clancy, Daniel (Technical Monitor)

2001-01-01

Weather is one of the major causes of general aviation accidents. Researchers are addressing this problem from various perspectives including improving meteorological forecasting techniques, collecting additional weather data automatically via on-board sensors and "flight" modems, and improving weather data dissemination and presentation. We approach the problem from the improved presentation perspective and propose weather visualization and interaction methods tailored for general aviation pilots. Our system, Aviation Weather Data Visualization Environment (AWE), utilizes information visualization techniques, a direct manipulation graphical interface, and a speech-based interface to improve a pilot's situational awareness of relevant weather data. The system design is based on a user study and feedback from pilots.

Methods and apparatus for analysis of chromatographic migration patterns

DOEpatents

Stockham, T.G.; Ives, J.T.

1993-12-28

A method and apparatus are presented for sharpening signal peaks in a signal representing the distribution of biological or chemical components of a mixture separated by a chromatographic technique such as, but not limited to, electrophoresis. A key step in the method is the use of a blind deconvolution technique, presently embodied as homomorphic filtering, to reduce the contribution of a blurring function to the signal encoding the peaks of the distribution. The invention further includes steps and apparatus directed to determination of a nucleotide sequence from a set of four such signals representing DNA sequence data derived by electrophoretic means. 16 figures.

Axillary Sonography of the Shoulder: An Adjunctive Approach.

PubMed

Michelin, Paul; Legrand, Julie; Lee, Kenneth S; Leleup, Grégoire; Etancelin, Mathilde; Banse, Christopher; Dacher, Jean-Nicolas; Duparc, Fabrice

2018-03-25

Sonography of the shoulder is widely used to assess various disorders, including tendinous diseases of the rotator cuff and the long head of the biceps brachii muscle. The shoulder is commonly explored through anterior, superior, and posterior approaches, but the inferior axillary approach is rarely considered in the literature. However, this technique allows the direct visualization of relevant anatomic structures. The aim of this pictorial essay is, first, to technically describe this approach and the normal musculoskeletal sonographic anatomy of the region and, second, to present the sonographic findings of shoulder disorders that may be helpfully explored this technique. © 2018 by the American Institute of Ultrasound in Medicine.

Efficient continuous-variable state tomography using Padua points

NASA Astrophysics Data System (ADS)

Landon-Cardinal, Olivier; Govia, Luke C. G.; Clerk, Aashish A.

Further development of quantum technologies calls for efficient characterization methods for quantum systems. While recent work has focused on discrete systems of qubits, much remains to be done for continuous-variable systems such as a microwave mode in a cavity. We introduce a novel technique to reconstruct the full Husimi Q or Wigner function from measurements done at the Padua points in phase space, the optimal sampling points for interpolation in 2D. Our technique not only reduces the number of experimental measurements, but remarkably, also allows for the direct estimation of any density matrix element in the Fock basis, including off-diagonal elements. OLC acknowledges financial support from NSERC.

Applications That Participate in Their Own Defense (APOD)

DTIC Science & Technology

2003-05-01

bandwidth requirements from multiple applications and uses ssh to directly login the RSVP routers to reconfigure the priority queues. This approach...detect flooding. 3 Emerald makes use of some signature matching techniques on BSM logs, but the unique strength of Emerald technology is in event...mechanisms that provide awareness, and IDSs form an important class of these4. We investigated several COTS and research IDSs including Emerald

Computer methods for sampling from the gamma distribution

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

Johnson, M.E.; Tadikamalla, P.R.

1978-01-01

Considerable attention has recently been directed at developing ever faster algorithms for generating gamma random variates on digital computers. This paper surveys the current state of the art including the leading algorithms of Ahrens and Dieter, Atkinson, Cheng, Fishman, Marsaglia, Tadikamalla, and Wallace. General random variate generation techniques are explained with reference to these gamma algorithms. Computer simulation experiments on IBM and CDC computers are reported.

NASA aerodynamics program

NASA Technical Reports Server (NTRS)

Williams, Louis J.; Hessenius, Kristin A.; Corsiglia, Victor R.; Hicks, Gary; Richardson, Pamela F.; Unger, George; Neumann, Benjamin; Moss, Jim

1992-01-01

The annual accomplishments is reviewed for the Aerodynamics Division during FY 1991. The program includes both fundamental and applied research directed at the full spectrum of aerospace vehicles, from rotorcraft to planetary entry probes. A comprehensive review is presented of the following aerodynamics elements: computational methods and applications; CFD validation; transition and turbulence physics; numerical aerodynamic simulation; test techniques and instrumentation; configuration aerodynamics; aeroacoustics; aerothermodynamics; hypersonics; subsonics; fighter/attack aircraft and rotorcraft.

Research directions in large scale systems and decentralized control

NASA Technical Reports Server (NTRS)

Tenney, R. R.

1980-01-01

Control theory provides a well established framework for dealing with automatic decision problems and a set of techniques for automatic decision making which exploit special structure, but it does not deal well with complexity. The potential exists for combining control theoretic and knowledge based concepts into a unified approach. The elements of control theory are diagrammed, including modern control and large scale systems.

Comprehensive Flood Plain Studies Using Spatial Data Management Techniques.

DTIC Science & Technology

1978-06-01

Hydrologic Engineer- ing Center computer programs that forecast urban storm water quality and dynamic in- stream water quality response to waste...determination. Water Quality The water quality analysis planned for the pilot study includes urban storm water quality forecasting and in-streamn...analysis is performed under the direction of Tony Thomas. Chief, Research Branch, by Jess Abbott for storm water quality analysis, R. G. Willey for

Developing the MD Explorer

NASA Astrophysics Data System (ADS)

Howie, Philip V.

1993-04-01

The MD Explorer is an eight-seat twin-turbine engine helicopter which is being developed using integrated product definition (IPD) team methodology. New techniques include NOTAR antitorque system for directional control, a composite fuselage, an all-composite bearingless main rotor, and digital cockpit displays. Three-dimensional CAD models are the basis of the entire Explorer design. Solid models provide vendor with design clarification, removing much of the normal drawing interpretation errors.

Charged-particle emission tomography

NASA Astrophysics Data System (ADS)

Ding, Yijun

Conventional charged-particle imaging techniques--such as autoradiography-- provide only two-dimensional (2D) images of thin tissue slices. To get volumetric information, images of multiple thin slices are stacked. This process is time consuming and prone to distortions, as registration of 2D images is required. We propose a direct three-dimensional (3D) autoradiography technique, which we call charged-particle emission tomography (CPET). This 3D imaging technique enables imaging of thick sections, thus increasing laboratory throughput and eliminating distortions due to registration. In CPET, molecules or cells of interest are labeled so that they emit charged particles without significant alteration of their biological function. Therefore, by imaging the source of the charged particles, one can gain information about the distribution of the molecules or cells of interest. Two special case of CPET include beta emission tomography (BET) and alpha emission tomography (alphaET), where the charged particles employed are fast electrons and alpha particles, respectively. A crucial component of CPET is the charged-particle detector. Conventional charged-particle detectors are sensitive only to the 2-D positions of the detected particles. We propose a new detector concept, which we call particle-processing detector (PPD). A PPD measures attributes of each detected particle, including location, direction of propagation, and/or the energy deposited in the detector. Reconstruction algorithms for CPET are developed, and reconstruction results from simulated data are presented for both BET and alphaET. The results show that, in addition to position, direction and energy provide valuable information for 3D reconstruction of CPET. Several designs of particle-processing detectors are described. Experimental results for one detector are discussed. With appropriate detector design and careful data analysis, it is possible to measure direction and energy, as well as position of each detected particle. The null functions of CPET with PPDs that measure different combinations of attributes are calculated through singular-value decomposition. In general, the more particle attributes are measured from each detection event, the smaller the null space of CPET is. In other words, the higher dimension the data space is, the more information about an object can be recovered from CPET.

A campus-based course in field geology

NASA Astrophysics Data System (ADS)

Richard, G. A.; Hanson, G. N.

2009-12-01

GEO 305: Field Geology offers students practical experience in the field and in the computer laboratory conducting geological field studies on the Stony Brook University campus. Computer laboratory exercises feature mapping techniques and field studies of glacial and environmental geology, and include geophysical and hydrological analysis, interpretation, and mapping. Participants learn to use direct measurement and mathematical techniques to compute the location and geometry of features and gain practical experience in representing raster imagery and vector geographic data as features on maps. Data collecting techniques in the field include the use of hand-held GPS devices, compasses, ground-penetrating radar, tape measures, pacing, and leveling devices. Assignments that utilize these skills and techniques include mapping campus geology with GPS, using Google Earth to explore our geologic context, data file management and ArcGIS, tape and compass mapping of woodland trails, pace and compass mapping of woodland trails, measuring elevation differences on a hillside, measuring geologic sections and cores, drilling through glacial deposits, using ground penetrating radar on glaciotectonic topography, mapping the local water table, and the identification and mapping of boulders. Two three-hour sessions are offered per week, apportioned as needed between lecture; discussion; guided hands-on instruction in geospatial and other software such as ArcGIS, Google Earth, spreadsheets, and custom modules such as an arc intersection calculator; outdoor data collection and mapping; and writing of illustrated reports.

Advances in top-down and bottom-up surface nanofabrication: techniques, applications & future prospects.

PubMed

Biswas, Abhijit; Bayer, Ilker S; Biris, Alexandru S; Wang, Tao; Dervishi, Enkeleda; Faupel, Franz

2012-01-15

This review highlights the most significant advances of the nanofabrication techniques reported over the past decade with a particular focus on the approaches tailored towards the fabrication of functional nano-devices. The review is divided into two sections: top-down and bottom-up nanofabrication. Under the classification of top-down, special attention is given to technical reports that demonstrate multi-directional patterning capabilities less than or equal to 100 nm. These include recent advances in lithographic techniques, such as optical, electron beam, soft, nanoimprint, scanning probe, and block copolymer lithography. Bottom-up nanofabrication techniques--such as, atomic layer deposition, sol-gel nanofabrication, molecular self-assembly, vapor-phase deposition and DNA-scaffolding for nanoelectronics--are also discussed. Specifically, we describe advances in the fabrication of functional nanocomposites and graphene using chemical and physical vapor deposition. Our aim is to provide a comprehensive platform for prominent nanofabrication tools and techniques in order to facilitate the development of new or hybrid nanofabrication techniques leading to novel and efficient functional nanostructured devices. Copyright © 2011 Elsevier B.V. All rights reserved.

Cerebral blood flow and autoregulation: current measurement techniques and prospects for noninvasive optical methods

PubMed Central

Fantini, Sergio; Sassaroli, Angelo; Tgavalekos, Kristen T.; Kornbluth, Joshua

2016-01-01

Abstract. Cerebral blood flow (CBF) and cerebral autoregulation (CA) are critically important to maintain proper brain perfusion and supply the brain with the necessary oxygen and energy substrates. Adequate brain perfusion is required to support normal brain function, to achieve successful aging, and to navigate acute and chronic medical conditions. We review the general principles of CBF measurements and the current techniques to measure CBF based on direct intravascular measurements, nuclear medicine, X-ray imaging, magnetic resonance imaging, ultrasound techniques, thermal diffusion, and optical methods. We also review techniques for arterial blood pressure measurements as well as theoretical and experimental methods for the assessment of CA, including recent approaches based on optical techniques. The assessment of cerebral perfusion in the clinical practice is also presented. The comprehensive description of principles, methods, and clinical requirements of CBF and CA measurements highlights the potentially important role that noninvasive optical methods can play in the assessment of neurovascular health. In fact, optical techniques have the ability to provide a noninvasive, quantitative, and continuous monitor of CBF and autoregulation. PMID:27403447

"Relative CIR": an image enhancement and visualization technique

USGS Publications Warehouse

Fleming, Michael D.

1993-01-01

Many techniques exist to spectrally and spatially enhance digital multispectral scanner data. One technique enhances an image while keeping the colors as they would appear in a color-infrared (CIR) image. This "relative CIR" technique generates an image that is both spectrally and spatially enhanced, while displaying a maximum range of colors. The technique enables an interpreter to visualize either spectral or land cover classes by their relative CIR characteristics. A relative CIR image is generated by developed spectral statistics for each class in the classifications and then, using a nonparametric approach for spectral enhancement, the means of the classes for each band are ranked. A 3 by 3 pixel smoothing filter is applied to the classification for spatial enhancement and the classes are mapped to the representative rank for each band. Practical applications of the technique include displaying an image classification product as a CIR image that was not derived directly from a spectral image, visualizing how a land cover classification would look as a CIR image, and displaying a spectral classification or intermediate product that will be used to label spectral classes.

Approaches for Achieving Broadband Achromatic Phase Shifts for Visible Nulling Coronagraphy

NASA Technical Reports Server (NTRS)

Bolcar, Matthew R.; Lyon, Richard G.

2012-01-01

Visible nulling coronagraphy is one of the few approaches to the direct detection and characterization of Jovian and Terrestrial exoplanets that works with segmented aperture telescopes. Jovian and Terrestrial planets require at least 10(exp -9) and 10(exp -10) image plane contrasts, respectively, within the spectral bandpass and thus require a nearly achromatic pi-phase difference between the arms of the interferometer. An achromatic pi-phase shift can be achieved by several techniques, including sequential angled thick glass plates of varying dispersive materials, distributed thin-film multilayer coatings, and techniques that leverage the polarization-dependent phase shift of total-internal reflections. Herein we describe two such techniques: sequential thick glass plates and Fresnel rhomb prisms. A viable technique must achieve the achromatic phase shift while simultaneously minimizing the intensity difference, chromatic beam spread and polarization variation between each arm. In this paper we describe the above techniques and report on efforts to design, model, fabricate, align the trades associated with each technique that will lead to an implementations of the most promising one in Goddard's Visible Nulling Coronagraph (VNC).

Autonomic Evaluation of Patients With Gastroparesis and Neurostimulation: Comparisons of Direct/Systemic and Indirect/Cardiac Measures

PubMed Central

Stocker, Abigail; Abell, Thomas L.; Rashed, Hani; Kedar, Archana; Boatright, Ben; Chen, Jiande

2016-01-01

Background Disorders of nausea, vomiting, abdominal pain, and related problems often are manifestations of gastrointestinal, neuromuscular, and/or autonomic dysfunction. Many of these patients respond to neurostimulation, either gastric electrical stimulation or electroacupuncture. Both of these therapeutic techniques appear to influence the autonomic nervous system which can be evaluated directly by traditional testing and indirectly by heart rate variability. Methods We studied patients undergoing gastric neuromodulation by both systemic autonomic testing (39 patients, six males and 33 females, mean age 38 years) and systemic autonomic testing and heart rate variability (35 patients, seven males and 28 females, mean age 37 years) testing before and after gastric neuromodulation. We also performed a pilot study using both systemic autonomic testing and heart rate variability in a small number of patients (five patients, all females, mean age 48.6 years) with diabetic gastroparesis at baseline to compare the two techniques at baseline. Systemic autonomic testing and heart rate variability were performed with standardized techniques and gastric electrical stimulation was performed as previously described with electrodes implanted serosally in the myenteric plexus. Results Both systemic autonomic testing and heart rate variability measures were often abnormal at baseline and showed changes after gastric neuromodulation therapy in two groups of symptomatic patients. Pilot data on a small group of similar patients with systemic automatic nervous measures and heart rate variability showed good concordance between the two techniques. Conclusions Both traditional direct autonomic measures and indirect measures such as heart rate variability were evaluated, including a pilot study of both methods in the same patient group. Both appear to be useful in evaluation of patients at baseline and after stimulation therapies; however, a future full head-to-head comparison is warranted. PMID:27785318

In-vivo Imaging of Magnetic Fields Induced by Transcranial Direct Current Stimulation (tDCS) in Human Brain using MRI

NASA Astrophysics Data System (ADS)

Jog, Mayank V.; Smith, Robert X.; Jann, Kay; Dunn, Walter; Lafon, Belen; Truong, Dennis; Wu, Allan; Parra, Lucas; Bikson, Marom; Wang, Danny J. J.

2016-10-01

Transcranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique that applies mA currents at the scalp to modulate cortical excitability. Here, we present a novel magnetic resonance imaging (MRI) technique, which detects magnetic fields induced by tDCS currents. This technique is based on Ampere’s law and exploits the linear relationship between direct current and induced magnetic fields. Following validation on a phantom with a known path of electric current and induced magnetic field, the proposed MRI technique was applied to a human limb (to demonstrate in-vivo feasibility using simple biological tissue) and human heads (to demonstrate feasibility in standard tDCS applications). The results show that the proposed technique detects tDCS induced magnetic fields as small as a nanotesla at millimeter spatial resolution. Through measurements of magnetic fields linearly proportional to the applied tDCS current, our approach opens a new avenue for direct in-vivo visualization of tDCS target engagement.

Simulation Modelling in Healthcare: An Umbrella Review of Systematic Literature Reviews.

PubMed

Salleh, Syed; Thokala, Praveen; Brennan, Alan; Hughes, Ruby; Booth, Andrew

2017-09-01

Numerous studies examine simulation modelling in healthcare. These studies present a bewildering array of simulation techniques and applications, making it challenging to characterise the literature. The aim of this paper is to provide an overview of the level of activity of simulation modelling in healthcare and the key themes. We performed an umbrella review of systematic literature reviews of simulation modelling in healthcare. Searches were conducted of academic databases (JSTOR, Scopus, PubMed, IEEE, SAGE, ACM, Wiley Online Library, ScienceDirect) and grey literature sources, enhanced by citation searches. The articles were included if they performed a systematic review of simulation modelling techniques in healthcare. After quality assessment of all included articles, data were extracted on numbers of studies included in each review, types of applications, techniques used for simulation modelling, data sources and simulation software. The search strategy yielded a total of 117 potential articles. Following sifting, 37 heterogeneous reviews were included. Most reviews achieved moderate quality rating on a modified AMSTAR (A Measurement Tool used to Assess systematic Reviews) checklist. All the review articles described the types of applications used for simulation modelling; 15 reviews described techniques used for simulation modelling; three reviews described data sources used for simulation modelling; and six reviews described software used for simulation modelling. The remaining reviews either did not report or did not provide enough detail for the data to be extracted. Simulation modelling techniques have been used for a wide range of applications in healthcare, with a variety of software tools and data sources. The number of reviews published in recent years suggest an increased interest in simulation modelling in healthcare.

Fabrication and Characterization of New Composite Tio2 Carbon Nanofiber Anodic Catalyst Support for Direct Methanol Fuel Cell via Electrospinning Method.

PubMed

Abdullah, N; Kamarudin, S K; Shyuan, L K; Karim, N A

2017-12-06

Platinum (Pt) is the common catalyst used in a direct methanol fuel cell (DMFC). However, Pt can lead towards catalyst poisoning by carbonaceous species, thus reduces the performance of DMFC. Thus, this study focuses on the fabrication of a new composite TiO 2 carbon nanofiber anodic catalyst support for direct methanol fuel cells (DMFCs) via electrospinning technique. The distance between the tip and the collector (DTC) and the flow rate were examined as influencing parameters in the electrospinning technique. To ensure that the best catalytic material is fabricated, the nanofiber underwent several characterizations and electrochemical tests, including FTIR, XRD, FESEM, TEM, and cyclic voltammetry. The results show that D18, fabricated with a flow rate of 0.1 mLhr -1 and DTC of 18 cm, is an ultrafine nanofiber with the smallest average diameter, 136.73 ± 39.56 nm. It presented the highest catalyst activity and electrochemical active surface area value as 274.72 mAmg -1 and 226.75m 2  g -1 PtRu , respectively, compared with the other samples.

Validation of oxygen extraction fraction measurement by qBOLD technique.

PubMed

He, Xiang; Zhu, Mingming; Yablonskiy, Dmitriy A

2008-10-01

Measurement of brain tissue oxygen extraction fraction (OEF) in both baseline and functionally activated states can provide important information on brain functioning in health and disease. The recently proposed quantitative BOLD (qBOLD) technique is MRI-based and provides a regional in vivo OEF measurement (He and Yablonskiy, MRM 2007, 57:115-126). It is based on a previously developed analytical BOLD model and incorporates prior knowledge about the brain tissue composition including the contributions from grey matter, white matter, cerebrospinal fluid, interstitial fluid and intravascular blood. The qBOLD model also allows for the separation of contributions to the BOLD signal from OEF and the deoxyhemoglobin containing blood volume (DBV). The objective of this study is to validate OEF measurements provided by the qBOLD approach. To this end we use a rat model and compare qBOLD OEF measurements against direct measurements of the blood oxygenation level obtained from venous blood drawn directly from the superior sagittal sinus. The cerebral venous oxygenation level of the rat was manipulated by utilizing different anestheisa methods. The study demonstrates a very good agreement between qBOLD approach and direct measurements. (c) 2008 Wiley-Liss, Inc.

Thermodynamic temperature assignment to the point of inflection of the melting curve of high-temperature fixed points.

PubMed

Woolliams, E R; Anhalt, K; Ballico, M; Bloembergen, P; Bourson, F; Briaudeau, S; Campos, J; Cox, M G; del Campo, D; Dong, W; Dury, M R; Gavrilov, V; Grigoryeva, I; Hernanz, M L; Jahan, F; Khlevnoy, B; Khromchenko, V; Lowe, D H; Lu, X; Machin, G; Mantilla, J M; Martin, M J; McEvoy, H C; Rougié, B; Sadli, M; Salim, S G R; Sasajima, N; Taubert, D R; Todd, A D W; Van den Bossche, R; van der Ham, E; Wang, T; Whittam, A; Wilthan, B; Woods, D J; Woodward, J T; Yamada, Y; Yamaguchi, Y; Yoon, H W; Yuan, Z

2016-03-28

The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 ± 0.18 K and 1597.39 ± 0.13 K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.80 ± 0.08 K, where the ± symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234 K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature. © 2016 The Author(s).

Multipath interference test method using synthesized chirped signal from directly modulated DFB-LD with digital-signal-processing technique.

PubMed

Aida, Kazuo; Sugie, Toshihiko

2011-12-12

We propose a method of testing transmission fiber lines and distributed amplifiers. Multipath interference (MPI) is detected as a beat spectrum between a multipath signal and a direct signal using a synthesized chirped test signal with lightwave frequencies of f(1) and f(2) periodically emitted from a distributed feedback laser diode (DFB-LD). This chirped test pulse is generated using a directly modulated DFB-LD with a drive signal calculated using a digital signal processing technique (DSP). A receiver consisting of a photodiode and an electrical spectrum analyzer (ESA) detects a baseband power spectrum peak appearing at the frequency of the test signal frequency deviation (f(1)-f(2)) as a beat spectrum of self-heterodyne detection. Multipath interference is converted from the spectrum peak power. This method improved the minimum detectable MPI to as low as -78 dB. We discuss the detailed design and performance of the proposed test method, including a DFB-LD drive signal calculation algorithm with DSP for synthesis of the chirped test signal and experiments on single-mode fibers with discrete reflections. © 2011 Optical Society of America

Plasma Source Development for LAPD

NASA Astrophysics Data System (ADS)

Pribyl, P.; Gekelman, W.; Drandell, M.; Grunspen, S.; Nakamoto, M.; McBarron, A.

2003-10-01

The Large Plasma Device (LAPD) relies on an indirectly heated Barium Oxide (BaO) cathode to generate an extremely repeatable low-noise plasma. However there are two defects of this system: one is that the cathode is subject to oxygen poisoning in the event of accidental air leaks, requiring a lengthy recoating and regeneration process. Second, the indirect radiative heating is only about 50 % efficient, leading to a series of reliability issues. Alternate plasma sources are being investigated, including two types of directly heated BaO cathode and several configurations of inductively coupled RF plasmas. Direct heating for a cathode can be achieved either by embedding heaters within the nickel substrate, or by using inductive heating techniques to drive currents within the nickel itself. In both cases, the BaO coating still serves to emit the electrons and thus generate the plasma arc. An improved system would generate the plasma without the use of a "cathode" e.g. by inductively coupling energy directly into the plasma discharge. This technique is being investigated from the point of view of whether a) the bulk of the plasma column can be made sufficiently low-noise to be of experimental value and b) sufficiently dense plasmas can be formed.

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

Lucia, M., E-mail: mlucia@pppl.gov; Kaita, R.; Majeski, R.

The Materials Analysis and Particle Probe (MAPP) is a compact in vacuo surface science diagnostic, designed to provide in situ surface characterization of plasma facing components in a tokamak environment. MAPP has been implemented for operation on the Lithium Tokamak Experiment at Princeton Plasma Physics Laboratory (PPPL), where all control and analysis systems are currently under development for full remote operation. Control systems include vacuum management, instrument power, and translational/rotational probe drive. Analysis systems include onboard Langmuir probes and all components required for x-ray photoelectron spectroscopy, low-energy ion scattering spectroscopy, direct recoil spectroscopy, and thermal desorption spectroscopy surface analysis techniques.

Crash Certification by Analysis - Are We There Yet?

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.; Lyle, Karen H.

2006-01-01

This paper addresses the issue of crash certification by analysis. This broad topic encompasses many ancillary issues including model validation procedures, uncertainty in test data and analysis models, probabilistic techniques for test-analysis correlation, verification of the mathematical formulation, and establishment of appropriate qualification requirements. This paper will focus on certification requirements for crashworthiness of military helicopters; capabilities of the current analysis codes used for crash modeling and simulation, including some examples of simulations from the literature to illustrate the current approach to model validation; and future directions needed to achieve "crash certification by analysis."

Double-row vs single-row rotator cuff repair: a review of the biomechanical evidence.

PubMed

Wall, Lindley B; Keener, Jay D; Brophy, Robert H

2009-01-01

A review of the current literature will show a difference between the biomechanical properties of double-row and single-row rotator cuff repairs. Rotator cuff tears commonly necessitate surgical repair; however, the optimal technique for repair continues to be investigated. Recently, double-row repairs have been considered an alternative to single-row repair, allowing a greater coverage area for healing and a possibly stronger repair. We reviewed the literature of all biomechanical studies comparing double-row vs single-row repair techniques. Inclusion criteria included studies using cadaveric, animal, or human models that directly compared double-row vs single-row repair techniques, written in the English language, and published in peer reviewed journals. Identified articles were reviewed to provide a comprehensive conclusion of the biomechanical strength and integrity of the repair techniques. Fifteen studies were identified and reviewed. Nine studies showed a statistically significant advantage to a double-row repair with regards to biomechanical strength, failure, and gap formation. Three studies produced results that did not show any statistical advantage. Five studies that directly compared footprint reconstruction all demonstrated that the double-row repair was superior to a single-row repair in restoring anatomy. The current literature reveals that the biomechanical properties of a double-row rotator cuff repair are superior to a single-row repair. Basic Science Study, SRH = Single vs. Double Row RCR.

Catheter-directed Endovascular Application of Thrombin: Report of 3 Cases and Review of the Literature

PubMed Central

Maybody, Majid; Madoff, David C.; Thornton, Raymond H; Morales, Steven A; Moskowitz, Chaya S; Hsu, Meier; Brody, Lynn A; Brown, Karen T; Covey, Anne M

2017-01-01

Purpose To report 3 new cases of catheter-directed endovascular application of thrombin and explore trends by analysis of published case series. Materials and Methods Institutional Review Board approved this retrospective study. All cases of non-tumoral arterial embolization performed from January 2003 to January 2015 at our institution were retrospectively reviewed. Thrombin was used in 7 of 589 cases. In 3 cases intra arterial thrombin was injected via catheter to treat active hemorrhage. Four cases were excluded due to percutaneous injection into visceral pseudoaneurysms (n=3) and making ex vivo autologous clot to be injected via catheter (n=1). Fisher’s exact and the Wilcoxon rank sum tests were used to assess for association with acute nontarget thrombosis. Results Catheter-directed thrombin was used in 3/589 (0.5%) cases at our institution. All three cases were technically successful with no further bleeding (100%). Nontarget thrombosis of proximal branches occurred in 2 patients (67%) with no significant clinical consequences. Including our 3 cases, a total of 28 cases were reviewed. Of the variables examined - location (p=0.99), size (p=0.66) and etiology of vascular lesion (p=0.92), pseudoaneurysm neck anatomy (p=0.14), thrombin units (p=0.47), volume (p=0.76) or technique of use of small doses (p=0.99), use of other embolic material (p=0.67) and use of adjunct techniques (p=0.99) - none were found to be significantly associated with acute nontarget thrombosis. Technical success was 96% with no reports of reperfusion after treatment. Conclusions Catheter-directed endovascular thrombin can be an additional tool to treat pseudoaneurysms not amenable to conventional embolization. Further studies are required to optimize technique and outcomes. PMID:27936421

Direct cost comparison of minimally invasive punch technique versus traditional approaches for percutaneous bone anchored hearing devices.

PubMed

Sardiwalla, Yaeesh; Jufas, Nicholas; Morris, David P

2017-06-12

Minimally Invasive Ponto Surgery (MIPS) was recently described as a new technique to facilitate the placement of percutaneous bone anchored hearing devices. The procedure has resulted in a simplification of the surgical steps and a dramatic reduction in surgical time while maintaining excellent patient outcomes. Given these developments, our group sought to move the procedure from the main operating suite where they have traditionally been performed. This study aims to test the null hypothesis that MIPS and open approaches have the same direct costs for the implantation of percutaneous bone anchored hearing devices in a Canadian public hospital setting. A retrospective direct cost comparison of MIPS and open approaches for the implantation of bone conduction implants was conducted. Indirect and future costs were not included in the fiscal analysis. A simple cost comparison of the two approaches was made considering time, staff and equipment needs. All 12 operations were performed on adult patients from 2013 to 2016 by the same surgeon at a single hospital site. MIPS has a total mean reduction in cost of CAD$456.83 per operation from the hospital perspective when compared to open approaches. The average duration of the MIPS operation was 7 min, which is on average 61 min shorter compared with open approaches. The MIPS technique was more cost effective than traditional open approaches. This primarily reflects a direct consequence of a reduction in surgical time, with further contributions from reduced staffing and equipment costs. This simple, quick intervention proved to be feasible when performed outside the main operating room. A blister pack of required equipment could prove convenient and further reduce costs.

Repair vs replacement of direct composite restorations: a survey of teaching and operative techniques in Oceania.

PubMed

Brunton, Paul A; Ghazali, Amna; Tarif, Zahidah H; Loch, Carolina; Lynch, Christopher; Wilson, Nairn; Blum, Igor R

2017-04-01

To evaluate the teaching and operative techniques for the repair and/or replacement of direct resin-based composite restorations (DCRs) in dental schools in Oceania. A 14-item questionnaire was mailed to the heads of operative dentistry in 16 dental schools in Oceania (Australia, New Zealand, Fiji and Papua New Guinea). The survey asked whether the repair of DCRs was taught within the curriculum; the rationale behind the teaching; how techniques were taught, indications for repair, operative techniques, materials used, patient acceptability, expected longevity and recall systems. All 16 schools participated in the study. Thirteen (81%) reported the teaching of composite repairs as an alternative to replacement. Most schools taught the theoretical and practical aspects of repair at a clinical level only. All 13 schools (100%) agreed on tooth substance preservation being the main reason for teaching repair. The main indications for repair were marginal defects (100%), followed by secondary caries (69%). All 13 schools that performed repairs reported high patient acceptability, and considered it a definitive measure. Only three schools (23%) claimed to have a recall system in place following repair of DCRs. Most respondents either did not know or did not answer when asked about the longevity of DCRs. Repair of DCRs seems to be a viable alternative to replacement, which is actively taught within Oceania. Advantages include it being minimally invasive, preserving tooth structure, and time and money saving. However, standardised guidelines need to be developed and further clinical long-term studies need to be carried out. The decision between replacing or repairing a defective composite restoration tends to be based on what clinicians have been taught, tempered by experience and judgement. This study investigated the current status of teaching and operative techniques of repair of direct composite restorations in dental schools in Oceania. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Two-motor direct drive control for elevation axis of telescope

NASA Astrophysics Data System (ADS)

Tang, T.; Tan, Y.; Ren, G.

2014-07-01

Two-motor application has become a very attractive filed in important field which high performance is permitted to achieve of position, speed, and acceleration. In the elevation axis of telescope control system, two-motor direct drive is proposed to enhance the high performance of tracking control system. Although there are several dominant strengths such as low size of motors and high torsional structural dynamics, the synchronization control of two motors is a very difficult and important. In this paper, a multi-loop control technique base master-slave current control is used to synchronize two motors, including current control loop, speed control loop and position control loop. First, the direct drive function of two motors is modeled. Compared of single motor direct control system, the resonance frequency of two motor control systems is same; while the anti-resonance frequency of two motors control system is 1.414 times than those of sing motor system. Because of rigid coupling for direct drive, the speed of two motor of the system is same, and the synchronization of torque for motors is critical. The current master-slave control technique is effective to synchronize the torque, which the current loop of the master motors is tracked the other slave motor. The speed feedback into the input of current loop of the master motors. The experiments test the performance of the two motors drive system. The random tracking error is 0.0119" for the line trajectory of 0.01°/s.

Laser direct writing of carbon/Au composite electrodes for high-performance micro-supercapacitors

NASA Astrophysics Data System (ADS)

Cai, Jinguang; Watanabe, Akira; Lv, Chao

2017-02-01

Micro-supercapacitors with small size, light weight, flexibility while maintaining high energy and power output are required for portable miniaturized electronics. The fabrication methods and materials should be cost-effective, scalable, and easily integrated to current electronic industry. Carbon materials have required properties for high-performance flexible supercapacitors, including high specific surface areas, electrochemical stability, and high electrical conductivity, as well as the high mechanical tolerance. Laser direct writing method is a non-contact, efficient, single-step fabrication technique without requirements of masks, post-processing, and complex clean room, which is a useful patterning technique, and can be easily integrated with current electronic product lines for commercial use. Previously we have reported micro-supercapacitors fabricated by laser direct writing on polyimide films in air or Ar, which showed highcapacitive performance. However, the conductivity of the carbon materials is still low for fast charge-discharge use. Here, we demonstrated the fabrication of flexible carbon/Au composite high-performance MSCs by first laser direct writing on commercial polyimide films followed by spin-coating Au nanoparticles ink and second in-situ laser direct writing using the low-cost semiconductor laser. As-prepared micro-supercapacitors show an improved conductivity and capacitance of 1.17 mF/cm2 at a high scanning rate of 10,000 mV/s, which is comparable to the reported capacitance of carbon-based micro-supercapacitors. In addition, the micro-supercapacitors have high bend tolerance and long-cycle stability.

Chemical analyses of fossil bone.

PubMed

Zheng, Wenxia; Schweitzer, Mary Higby

2012-01-01

The preservation of microstructures consistent with soft tissues, cells, and other biological components in demineralized fragments of dinosaur bone tens of millions of years old was unexpected, and counter to current hypotheses of tissue, cellular, and molecular degradation. Although the morphological similarity of these tissues to extant counterparts was unmistakable, after at least 80 million years exposed to geochemical influences, morphological similarity is insufficient to support an endogenous source. To test this hypothesis, and to characterize these materials at a molecular level, we applied multiple independent chemical, molecular, and microscopic analyses to identify the presence of original components produced by the extinct organisms. Microscopic techniques included field emission scanning electron microscopy, analytical transmission electron microscopy, transmitted light microscopy (LM), and fluorescence microscopy (FM). The chemical and molecular techniques include enzyme-linked immunosorbant assay, sodium dodecyl sulfate polyacrylamide gel electrophoresis, western blot (immunoblot), and attenuated total reflectance infrared spectroscopy. In situ analyses performed directly on tissues included immunohistochemistry and time-of-flight secondary ion mass spectrometry. The details of sample preparation and methodology are described in detail herein.

Method for high resolution magnetic resonance analysis using magic angle technique

DOEpatents

Wind, Robert A.; Hu, Jian Zhi

2003-12-30

A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.

Method for high resolution magnetic resonance analysis using magic angle technique

DOEpatents

Wind, Robert A.; Hu, Jian Zhi

2004-12-28

A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.

Technique to determine location of radio sources from measurements taken on spinning spacecraft

NASA Technical Reports Server (NTRS)

Fainberg, J.

1979-01-01

The procedure developed to extract average source direction and average source size from spin-modulated radio astronomy data measured on the IMP-6 spacecraft is described. Because all measurements are used, rather than just finding maxima or minima in the data, the method is very sensitive, even in the presence of large amounts of noise. The technique is applicable to all experiments with directivity characteristics. It is suitable for onboard processing on satellites to reduce the data flow to Earth. The application to spin-modulated nonpolarized radio astronomy data is made and includes the effects of noise, background, and second source interference. The analysis was tested with computer simulated data and the results agree with analytic predictions. Applications of this method with IMP-6 radio data have led to: (1) determination of source positions of traveling solar radio bursts at large distances from the Sun; (2) mapping of magnetospheric radio emissions by radio triangulation; and (3) detection of low frequency radio emissions from Jupiter and Saturn.

Hypothesis-driven methods to augment human cognition by optimizing cortical oscillations

PubMed Central

Horschig, Jörn M.; Zumer, Johanna M.; Bahramisharif, Ali

2014-01-01

Cortical oscillations have been shown to represent fundamental functions of a working brain, e.g., communication, stimulus binding, error monitoring, and inhibition, and are directly linked to behavior. Recent studies intervening with these oscillations have demonstrated effective modulation of both the oscillations and behavior. In this review, we collect evidence in favor of how hypothesis-driven methods can be used to augment cognition by optimizing cortical oscillations. We elaborate their potential usefulness for three target groups: healthy elderly, patients with attention deficit/hyperactivity disorder, and healthy young adults. We discuss the relevance of neuronal oscillations in each group and show how each of them can benefit from the manipulation of functionally-related oscillations. Further, we describe methods for manipulation of neuronal oscillations including direct brain stimulation as well as indirect task alterations. We also discuss practical considerations about the proposed techniques. In conclusion, we propose that insights from neuroscience should guide techniques to augment human cognition, which in turn can provide a better understanding of how the human brain works. PMID:25018706

Capturing the genetic makeup of the active microbiome in situ.

PubMed

Singer, Esther; Wagner, Michael; Woyke, Tanja

2017-09-01

More than any other technology, nucleic acid sequencing has enabled microbial ecology studies to be complemented with the data volumes necessary to capture the extent of microbial diversity and dynamics in a wide range of environments. In order to truly understand and predict environmental processes, however, the distinction between active, inactive and dead microbial cells is critical. Also, experimental designs need to be sensitive toward varying population complexity and activity, and temporal as well as spatial scales of process rates. There are a number of approaches, including single-cell techniques, which were designed to study in situ microbial activity and that have been successively coupled to nucleic acid sequencing. The exciting new discoveries regarding in situ microbial activity provide evidence that future microbial ecology studies will indispensably rely on techniques that specifically capture members of the microbiome active in the environment. Herein, we review those currently used activity-based approaches that can be directly linked to shotgun nucleic acid sequencing, evaluate their relevance to ecology studies, and discuss future directions.

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

Afzal, Muhammad U., E-mail: muhammad.afzal@mq.edu.au; Esselle, Karu P.

This paper presents a quasi-analytical technique to design a continuous, all-dielectric phase correcting structures (PCSs) for circularly polarized Fabry-Perot resonator antennas (FPRAs). The PCS has been realized by varying the thickness of a rotationally symmetric dielectric block placed above the antenna. A global analytical expression is derived for the PCS thickness profile, which is required to achieve nearly uniform phase distribution at the output of the PCS, despite the non-uniform phase distribution at its input. An alternative piecewise technique based on spline interpolation is also explored to design a PCS. It is shown from both far- and near-field results thatmore » a PCS tremendously improves the radiation performance of the FPRA. These improvements include an increase in peak directivity from 22 to 120 (from 13.4 dBic to 20.8 dBic) and a decrease of 3 dB beamwidth from 41.5° to 15°. The phase-corrected antenna also has a good directivity bandwidth of 1.3 GHz, which is 11% of the center frequency.« less

Capturing the genetic makeup of the active microbiome in situ

PubMed Central

Singer, Esther; Wagner, Michael; Woyke, Tanja

2017-01-01

More than any other technology, nucleic acid sequencing has enabled microbial ecology studies to be complemented with the data volumes necessary to capture the extent of microbial diversity and dynamics in a wide range of environments. In order to truly understand and predict environmental processes, however, the distinction between active, inactive and dead microbial cells is critical. Also, experimental designs need to be sensitive toward varying population complexity and activity, and temporal as well as spatial scales of process rates. There are a number of approaches, including single-cell techniques, which were designed to study in situ microbial activity and that have been successively coupled to nucleic acid sequencing. The exciting new discoveries regarding in situ microbial activity provide evidence that future microbial ecology studies will indispensably rely on techniques that specifically capture members of the microbiome active in the environment. Herein, we review those currently used activity-based approaches that can be directly linked to shotgun nucleic acid sequencing, evaluate their relevance to ecology studies, and discuss future directions. PMID:28574490

Development of a model of space station solar array

NASA Technical Reports Server (NTRS)

Bosela, Paul A.

1990-01-01

Space structures, such as the space station solar arrays, must be extremely lightweight, flexible structures. Accurate prediction of the natural frequencies and mode shapes is essential for determining the structural adequacy of components, and designing a control system. The tension preload in the blanket of photovoltaic solar collectors, and the free/free boundary conditions of a structure in space, causes serious reservations on the use of standard finite element techniques of solution. In particular, a phenomena known as grounding, or false stiffening, of the stiffness matrix occurs during rigid body rotation. The grounding phenomena is examined in detail. Numerous stiffness matrices developed by others are examined for rigid body rotation capability, and found lacking. Various techniques are used for developing new stiffness matrices from the rigorous solutions of the differential equations, including the solution of the directed force problem. A new directed force stiffness matrix developed by the author provides all the rigid body capabilities for the beam in space.

Residual stress analysis for oxide thin film deposition on flexible substrate using finite element method

NASA Astrophysics Data System (ADS)

Chen, Hsi-Chao; Huang, Chen-Yu; Lin, Ssu-Fan; Chen, Sheng-Hui

2011-09-01

Residual or internal stresses directly affect a variety of phenomena including adhesion, generation of crystalline defects, perfection of epitaxial layers and formation of film surface growths such as hillocks and whiskers. Sputtering oxide films with high density promote high compressive stress, and it offers researchers a reference if the value of residual stress could be analyzed directly. Since, the study of residual stress of SiO2 and Nb2O5 thin film deposited by DC magnetron sputtered on hard substrate (BK7) and flexible substrate (PET and PC). A finite element method (FEM) with an equivalent-reference-temperature (ERT) technique had been proposed and used to model and evaluate the intrinsic strains of layered structures. The research has improved the equivalent reference temperature (ERT) technique of the simulation of intrinsic strain for oxygen film. The results have also generalized two models connecting to the lattice volume to predict the residual stress of hard substrate and flexible substrate with error of 3% and 6%, respectively.

Identification of diazotrophic microorganisms in marine sediment via fluorescence in situ hybridization coupled to nanoscale secondary ion mass spectrometry (FISH-NanoSIMS).

PubMed

Dekas, Anne E; Orphan, Victoria J

2011-01-01

Growing appreciation for the biogeochemical significance of uncultured microorganisms is changing the focus of environmental microbiology. Techniques designed to investigate microbial metabolism in situ are increasingly popular, from mRNA-targeted fluorescence in situ hybridization (FISH) to the "-omics" revolution, including metagenomics, transcriptomics, and proteomics. Recently, the coupling of FISH with nanometer-scale secondary ion mass spectrometry (NanoSIMS) has taken this movement in a new direction, allowing single-cell metabolic analysis of uncultured microbial phylogenic groups. The main advantage of FISH-NanoSIMS over previous noncultivation-based techniques to probe metabolism is its ability to directly link 16S rRNA phylogenetic identity to metabolic function. In the following chapter, we describe the procedures necessary to identify nitrogen-fixing microbes within marine sediment via FISH-NanoSIMS, using our work on nitrogen fixation by uncultured deep-sea methane-consuming archaea as a case study. Copyright © 2011 Elsevier Inc. All rights reserved.

Actinic Flux Calculations: A Model Sensitivity Study

NASA Technical Reports Server (NTRS)

Krotkov, Nickolay A.; Flittner, D.; Ahmad, Z.; Herman, J. R.; Einaudi, Franco (Technical Monitor)

2000-01-01

calculate direct and diffuse surface irradiance and actinic flux (downwelling (2p) and total (4p)) for the reference model. Sensitivity analysis has shown that the accuracy of the radiative transfer flux calculations for a unit ETS (i.e. atmospheric transmittance) together with a numerical interpolation technique for the constituents' vertical profiles is better than 1% for SZA less than 70(sub o) and wavelengths longer than 310 nm. The differences increase for shorter wavelengths and larger SZA, due to the differences in pseudo-spherical correction techniques and vertical discretetization among the codes. Our sensitivity study includes variation of ozone cross-sections, ETS spectra and the effects of wavelength shifts between vacuum and air scales. We also investigate the effects of aerosols on the spectral flux components in the UV and visible spectral regions. The "aerosol correction factors" (ACFs) were calculated at discrete wavelengths and different SZAs for each flux component (direct, diffuse, reflected) and prescribed IPMMI aerosol parameters. Finally, the sensitivity study was extended to calculation of selected photolysis rates coefficients.

Corrosion of Ti6Al4V pins produced by direct metal laser sintering

NASA Astrophysics Data System (ADS)

de Damborenea, J. J.; Arenas, M. A.; Larosa, Maria Aparecida; Jardini, André Luiz; de Carvalho Zavaglia, Cecília Amélia; Conde, A.

2017-01-01

Direct Metal Laser Sintering (DMLS) technique allows the manufacturing a wide variety of medical devices for any type of prosthetic surgery (HIP, dental, cranial, maxillofacial) as well as for internal fixation devices (K-Wires or Steinmann Pins). There are a large number of research studies on DMLS, including microstructural characterization, mechanical properties and those based on production quality assurance but the influence of porosity in the corrosion behavior of these materials not been sufficiently considered. In the present paper, surgical pins of Ti6Al4V have been produced by DMLS. After testing in a phosphate buffered saline solution, the surface of the titanium alloy appeared locally covered by a voluminous white oxide. This unexpected behavior was presumably due to the existence of internal defects in the pins as result of the manufacturing process. The importance of these defects-that might act as crevice nucleation sites- has been revealed by electrochemical techniques and confirmed by computed tomography.

Structural coloration of metallic surfaces with micro/nano-structures induced by elliptical vibration texturing

NASA Astrophysics Data System (ADS)

Yang, Yang; Pan, Yayue; Guo, Ping

2017-04-01

Creating orderly periodic micro/nano-structures on metallic surfaces, or structural coloration, for control of surface apparent color and optical reflectivity has been an exciting research topic over the years. The direct applications of structural coloration include color marking, display devices, and invisibility cloak. This paper presents an efficient method to colorize metallic surfaces with periodic micro/nano-gratings using elliptical vibration texturing. When the tool vibration is coupled with a constant cutting velocity, controlled periodic ripples can be generated due to the overlapping tool trajectory. These periodic ripples with a wavelength near visible spectrum can act as micro-gratings to introduce iridescent colors. The proposed technique also provides a flexible method for color marking of metallic surfaces with arbitrary patterns and images by precise control of the spacing distance and orientation of induced micro/nano-ripples. Theoretical analysis and experimental results are given to demonstrate structural coloration of metals by a direct mechanical machining technique.

Review article: gut-directed hypnotherapy in the management of irritable bowel syndrome and inflammatory bowel disease.

PubMed

Peters, S L; Muir, J G; Gibson, P R

2015-06-01

Gut-directed hypnotherapy is being increasingly applied to patients with irritable bowel syndrome (IBS) and to a lesser extent, inflammatory bowel disease (IBD). To review the technique, mechanisms of action and evidence for efficacy, and to identify gaps in the understanding of gut-directed hypnotherapy as a treatment for IBS and IBD. A review of published literature and a systematic review of clinical trials in its application to patients with IBS and IBD were performed. Gut-directed hypnotherapy is a clearly described technique. Its potential mechanisms of action on the brain-gut axis are multiple with evidence spanning psychological effects through to physiological gastrointestinal modifications. Six of seven randomised IBS studies reported a significant reduction (all P < 0.05) in overall gastrointestinal symptoms following treatment usually compared to supportive therapy only. Response rates amongst those who received gut-directed hypnotherapy ranged between 24% and 73%. Efficacy was maintained long-term in four of five studies. A therapeutic effect was also observed in the maintenance of clinical remission in patients with ulcerative colitis. Uncontrolled trials supported the efficacy and durability of gut-directed hypnotherapy in IBS. Gaps in understanding included to whom and when it should be applied, the paucity of adequately trained hypnotherapists, and the difficulties in designing well controlled-trials. Gut-directed hypnotherapy has durable efficacy in patients with IBS and possibly ulcerative colitis. Whether it sits in the therapeutic arsenal as a primary and/or adjunctive therapy cannot be ascertained on the current evidence base. Further research into efficacy, mechanisms of action and predictors of response is required. © 2015 John Wiley & Sons Ltd.

Essential features of residual stress determination in thin-walled plane structures in a base of whole field interferometric measurements

NASA Astrophysics Data System (ADS)

Pisarev, Vladimir S.; Odintsev, I.; Balalov, V.; Apalkov, A.

2003-05-01

Sophisticated technique for reliable quantitative deriving residual stress values from initial experimental data, which are inherent in combined implementing the hole drilling method with both holographic and speckle interferometry, is described in detail. The approach developed includes both possible ways of obtaining initial experimental information. The first of them consists of recording a set of required interference fringe patterns, which are resulted from residual stress energy release after through hole drilling, in two orthogonal directions that coincide with principal strain directions. The second way is obtaining a series of interrelated fringe patterns when a direction of either observation in reflection hologram interferometry or dual-beam illumination in speckle interferometry lies arbitrary with respect to definite principal strain direction. A set of the most typical both actual and analogous reference fringe patterns, which are related to both reflection hologram and dual-beam speckle interferometry, are presented.

Effects of Angle of Attack and Velocity on Trailing Edge Noise

NASA Technical Reports Server (NTRS)

Hutcheson, Florence V.; Brooks, Thomas F.

2006-01-01

Trailing edge (TE) noise measurements for a NACA 63-215 airfoil model are presented, providing benchmark experimental data for a cambered airfoil. The effects of flow Mach number and angle of attack of the airfoil model with different TE bluntnesses are shown. Far-field noise spectra and directivity are obtained using a directional microphone array. Standard and diagonal removal beamforming techniques are evaluated employing tailored weighting functions for quantitatively accounting for the distributed line character of TE noise. Diagonal removal processing is used for the primary database as it successfully removes noise contaminates. Some TE noise predictions are reported to help interpret the data, with respect to flow speed, angle of attack, and TE bluntness on spectral shape and peak levels. Important findings include the validation of a TE noise directivity function for different airfoil angles of attack and the demonstration of the importance of the directivity function s convective amplification terms.

Direct estimation of diffuse gaseous emissions from coal fires: current methods and future directions

USGS Publications Warehouse

Engle, Mark A.; Olea, Ricardo A.; O'Keefe, Jennifer M. K.; Hower, James C.; Geboy, Nicholas J.

2013-01-01

Coal fires occur in nature spontaneously, contribute to increases in greenhouse gases, and emit atmospheric toxicants. Increasing interest in quantifying coal fire emissions has resulted in the adaptation and development of specialized approaches and adoption of numerical modeling techniques. Overview of these methods for direct estimation of diffuse gas emissions from coal fires is presented in this paper. Here we take advantage of stochastic Gaussian simulation to interpolate CO2 fluxes measured using a dynamic closed chamber at the Ruth Mullins coal fire in Perry County, Kentucky. This approach allows for preparing a map of diffuse gas emissions, one of the two primary ways that gases emanate from coal fires, and establishing the reliability of the study both locally and for the entire fire. Future research directions include continuous and automated sampling to improve quantification of gaseous coal fire emissions.

Tables of asymptotic directions, cutoff rigidities, and reentrant albedo calculations for Palestine, Dallas, and Midland, Texas. Special repts

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

Shea, M.A.; Smart, D.F.

1974-03-26

Using the trajectory-tracing technique, the asymptotic directions and cut-off rigidities for Palestine, Dallas, amd Midland,Texas were calculated as a function of various zenith and azimuth angles. Continuation of the trajectory-tracing process below the Stormer cutoff allows an evaluation of the reentrant albedo; the invariant latitude of the guiding center of the trajectory at the albedo origin is seen to be the same as the invariant latitude of the guiding center of the particle trajectory at the specified zenith and azimuth angle of the detection point. Tables of asymptotic directions, cutoff rigidities, and the location of the reentrant albedo for eachmore » of these locations are given. Summaries of cutoff rigidity calculations as a function of zenith and azimuth directions for some miscellaneous locations are also included. (GRA)« less

Vertical directivities of seismic arrays on the ground surface

NASA Astrophysics Data System (ADS)

Shiraishi, H.; Asanuma, H.

2012-12-01

Microtremor survey method (MSM) is a technique to estimate subsurface velocity structures by inverting phase velocities of the surface waves in the microtremors. We can explorer the S-wave velocity structures at significantly lower expenses by the MSM than the conventional geophysical techniques because of its passive nature. Coherent waves across an array are identified in the MSM, and, therefore, all the existing velocity inversion methods have been deduced under an implicit assumption of horizontal velocity structure. However, it is expected that the development of the 3D inversion theory would drastically enhance applicability and reliability of the MSM. We, hence, investigated the characteristics of vertical directivities of the arrays deployed on the ground surface as an initial step for deriving the 3D MSM. We have firstly examined the response of an elemental two sensor array to which plane waves propagates from the deep crust with a certain angle of incident, and then examined the characteristics of several types of arrays, including triangular and circular arrays to clarify the characteristics of practical arrays. Real part of the complex coherence function, which has been derived to evaluate coherence of the Rayleigh wave between sensors for plane waves (Shiraishi et al., 2006), has been applied for this investigation. Our results showed that the directivity varies according to a parameter kr ( k : wave number, r : separation of the sensors ). A vertical directivity of two sensor array at kr = π shows a rotationally-symmetrical shape (Figure (a)). In contrast, an equilateral triangle array has a conspicuous directivity toward the vertical direction (cf. Figure (b)). This divergence suggests that the shape of the vertical directivity significantly depend on the geometry, and a sharp directivity toward just beneath the array can be realized by designing the vertical directivity. We concluded from this study that 3D MSM is feasible and further study to investigate measurement and processing theories will be made by the authors. An example of the vertical directivity at kr=π. Red circles represent the sensors.

Improving Focal Depth Estimates: Studies of Depth Phase Detection at Regional Distances

NASA Astrophysics Data System (ADS)

Stroujkova, A.; Reiter, D. T.; Shumway, R. H.

2006-12-01

The accurate estimation of the depth of small, regionally recorded events continues to be an important and difficult explosion monitoring research problem. Depth phases (free surface reflections) are the primary tool that seismologists use to constrain the depth of a seismic event. When depth phases from an event are detected, an accurate source depth is easily found by using the delay times of the depth phases relative to the P wave and a velocity profile near the source. Cepstral techniques, including cepstral F-statistics, represent a class of methods designed for the depth-phase detection and identification; however, they offer only a moderate level of success at epicentral distances less than 15°. This is due to complexities in the Pn coda, which can lead to numerous false detections in addition to the true phase detection. Therefore, cepstral methods cannot be used independently to reliably identify depth phases. Other evidence, such as apparent velocities, amplitudes and frequency content, must be used to confirm whether the phase is truly a depth phase. In this study we used a variety of array methods to estimate apparent phase velocities and arrival azimuths, including beam-forming, semblance analysis, MUltiple SIgnal Classification (MUSIC) (e.g., Schmidt, 1979), and cross-correlation (e.g., Cansi, 1995; Tibuleac and Herrin, 1997). To facilitate the processing and comparison of results, we developed a MATLAB-based processing tool, which allows application of all of these techniques (i.e., augmented cepstral processing) in a single environment. The main objective of this research was to combine the results of three focal-depth estimation techniques and their associated standard errors into a statistically valid unified depth estimate. The three techniques include: 1. Direct focal depth estimate from the depth-phase arrival times picked via augmented cepstral processing. 2. Hypocenter location from direct and surface-reflected arrivals observed on sparse networks of regional stations using a Grid-search, Multiple-Event Location method (GMEL; Rodi and Toksöz, 2000; 2001). 3. Surface-wave dispersion inversion for event depth and focal mechanism (Herrmann and Ammon, 2002). To validate our approach and provide quality control for our solutions, we applied the techniques to moderated- sized events (mb between 4.5 and 6.0) with known focal mechanisms. We illustrate the techniques using events observed at regional distances from the KSAR (Wonju, South Korea) teleseismic array and other nearby broadband three-component stations. Our results indicate that the techniques can produce excellent agreement between the various depth estimates. In addition, combining the techniques into a "unified" estimate greatly reduced location errors and improved robustness of the solution, even if results from the individual methods yielded large standard errors.

Heat-pump cool storage in a clathrate of freon

NASA Astrophysics Data System (ADS)

Tomlinson, J. J.

Presented are the analytical description and assessment of a unique heat pump/storage system in which the conventional evaporator of the vapor compression cycle is replaced by a highly efficient direct contract crystallizer. The thermal storage technique requires the formation of a refrigerant gas hydrate (a clathrate) and exploits an enthalpy of reaction comparable to the heat of fusion of ice. Additional system operational benefits include cool storage at the favorable temperatures of 4 to 7 C (40 to 45 F), and highly efficient heat transfer ates afforded by he direct contact mechanism. In addition, the experimental approach underway at ORNL to study such a system is discussed.

A SAT Based Effective Algorithm for the Directed Hamiltonian Cycle Problem

NASA Astrophysics Data System (ADS)

Jäger, Gerold; Zhang, Weixiong

The Hamiltonian cycle problem (HCP) is an important combinatorial problem with applications in many areas. While thorough theoretical and experimental analyses have been made on the HCP in undirected graphs, little is known for the HCP in directed graphs (DHCP). The contribution of this work is an effective algorithm for the DHCP. Our algorithm explores and exploits the close relationship between the DHCP and the Assignment Problem (AP) and utilizes a technique based on Boolean satisfiability (SAT). By combining effective algorithms for the AP and SAT, our algorithm significantly outperforms previous exact DHCP algorithms including an algorithm based on the award-winning Concorde TSP algorithm.

Direct-current vertical electrical-resistivity soundings in the Lower Peninsula of Michigan

USGS Publications Warehouse

Westjohn, D.B.; Carter, P.J.

1989-01-01

Ninety-three direct-current vertical electrical-resistivity soundings were conducted in the Lower Peninsula of Michigan from June through October 1987. These soundings were made to assist in mapping the depth to brine in areas where borehole resistivity logs and water-quality data are sparse or lacking. The Schlumberger array for placement of current and potential electrodes was used for each sounding. Vertical electrical-resistivity sounding field data, shifted and smoothed sounding data, and electric layers calculated using inverse modeling techniques are presented. Also included is a summary of the near-surface conditions and depths to conductors and resistors for each sounding location.

Direct Liquid Sampling for Corona Discharge Ion Mobility Spectrometry.

PubMed

Sabo, Martin; Malásková, Michaela; Harmathová, Olga; Hradski, Jasna; Masár, Marián; Radjenovic, Branislav; Matejčík, Štefan

2015-07-21

We present a new technique suitable for direct liquid sampling and analysis by ion mobility spectrometry (IMS). The technique is based on introduction of a droplet stream to the IMS reaction region. The technique was successfully used to detect explosives dissolved in methanol and oil as well as to analyze amino acids and dipeptides. One of the main advantages of this technique is its ability to analyze liquid samples without the requirement of any special solution.

Teaching of direct posterior resin composite restorations in UK dental therapy training programmes.

PubMed

Lynch, C D; Wilson, N H F

2010-05-08

With the numbers of dental therapists involved in the delivery of dental care within the UK on the increase, and the trend towards the use of direct resin composites (composites) for the restoration of posterior teeth, this study was undertaken to describe the teaching of posterior composites in dental therapy training programmes in the UK. A secondary aim was to identify differences in techniques for posterior composites taught within these dental therapy training programmes. In 2008/9, a questionnaire seeking information on the teaching of posterior composites was distributed by email to 13 centres with dental therapy training programmes in the UK. This questionnaire sought information relating to the teaching of direct posterior composites to dental therapy students, including the amounts of preclinical and clinical teaching in respect of deciduous and permanent teeth, numbers of restorations placed, contraindications to placement, and details in respect of operative techniques. Ten completed responses were received (response rate = 77%). In ten programmes, student dental therapists received clinical training in the placement of composite restorations in the occlusal surfaces of premolar and permanent molar teeth, and nine programmes included such training for two and three surface occlusoproximal restorations. The mean proportions of posterior restorations placed clinically by the trainee dental therapists in permanent teeth using dental amalgam and composite were 52% and 46% respectively (range: amalgam = 20-95%; composite = 5-70%). With the exception of one programme, the teaching of posterior composites is a well established element of dental therapy training. Some variations were noted in the teaching of clinical techniques between respondent training centres. It is suggested that to ensure harmony in approaches to treatments provided by graduated therapists that training centres look to relevant consensus documents, such as those of the British Association for the Teaching of Conservative Dentistry. The findings of our study are important for the future provision of oral healthcare, given the growing evidence base in favour of minimally invasive dentistry.

Various diffusion magnetic resonance imaging techniques for pancreatic cancer

PubMed Central

Tang, Meng-Yue; Zhang, Xiao-Ming; Chen, Tian-Wu; Huang, Xiao-Hua

2015-01-01

Pancreatic cancer is one of the most common malignant tumors and remains a treatment-refractory cancer with a poor prognosis. Currently, the diagnosis of pancreatic neoplasm depends mainly on imaging and which methods are conducive to detecting small lesions. Compared to the other techniques, magnetic resonance imaging (MRI) has irreplaceable advantages and can provide valuable information unattainable with other noninvasive or minimally invasive imaging techniques. Advances in MR hardware and pulse sequence design have particularly improved the quality and robustness of MRI of the pancreas. Diffusion MR imaging serves as one of the common functional MRI techniques and is the only technique that can be used to reflect the diffusion movement of water molecules in vivo. It is generally known that diffusion properties depend on the characterization of intrinsic features of tissue microdynamics and microstructure. With the improvement of the diffusion models, diffusion MR imaging techniques are increasingly varied, from the simplest and most commonly used technique to the more complex. In this review, the various diffusion MRI techniques for pancreatic cancer are discussed, including conventional diffusion weighted imaging (DWI), multi-b DWI based on intra-voxel incoherent motion theory, diffusion tensor imaging and diffusion kurtosis imaging. The principles, main parameters, advantages and limitations of these techniques, as well as future directions for pancreatic diffusion imaging are also discussed. PMID:26753059

A New Technique using Electron Velocity Data from the Four Cluster Spacecraft to Explore Magnetofluid Turbulence in the Solar Wind

NASA Technical Reports Server (NTRS)

Goldstein, Melvyn L.; Gurgiolo, C.; Fazakerley, A.; Lahiff, A.

2008-01-01

It is now possible in certain circumstances to use velocity moments computed from the Plasma Electron and Current Experiment (PEACE) on the four Cluster spacecraft to determine a number of turbulence properties of the solar wind, including direct measurements of the vorticity and compressibility. Assuming that the four spacecraft are not co-planar and that there is only a linear variation of the plasma variables across the volume defined by the four satellites, one can estimate the curl of the fluid velocity, i.e., the vorticity. From the vorticity it is possible to explore directly intermittent regions in the solar wind where dissipation is likely to be enhanced. In addition, one can estimate directly the Taylor microscale.

A fast direct solver for boundary value problems on locally perturbed geometries

NASA Astrophysics Data System (ADS)

Zhang, Yabin; Gillman, Adrianna

2018-03-01

Many applications including optimal design and adaptive discretization techniques involve solving several boundary value problems on geometries that are local perturbations of an original geometry. This manuscript presents a fast direct solver for boundary value problems that are recast as boundary integral equations. The idea is to write the discretized boundary integral equation on a new geometry as a low rank update to the discretized problem on the original geometry. Using the Sherman-Morrison formula, the inverse can be expressed in terms of the inverse of the original system applied to the low rank factors and the right hand side. Numerical results illustrate for problems where perturbation is localized the fast direct solver is three times faster than building a new solver from scratch.

Discovery and Development of Kelch-like ECH-Associated Protein 1. Nuclear Factor Erythroid 2-Related Factor 2 (KEAP1:NRF2) Protein-Protein Interaction Inhibitors: Achievements, Challenges, and Future Directions.

PubMed

Jiang, Zheng-Yu; Lu, Meng-Chen; You, Qi-Dong

2016-12-22

The transcription factor Nrf2 is the primary regulator of the cellular defense system, and enhancing Nrf2 activity has potential usages in various diseases, especially chronic age-related and inflammatory diseases. Recently, directly targeting Keap1-Nrf2 protein-protein interaction (PPI) has been an emerging strategy to selectively and effectively activate Nrf2. This Perspective summarizes the progress in the discovery and development of Keap1-Nrf2 PPI inhibitors, including the Keap1-Nrf2 regulatory mechanisms, biochemical techniques for inhibitor identification, and approaches for identifying peptide and small-molecule inhibitors, as well as discusses privileged structures and future directions for further development of Keap1-Nrf2 PPI inhibitors.

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

Overview of the CHarring Ablator Response (CHAR) Code

NASA Technical Reports Server (NTRS)

Amar, Adam J.; Oliver, A. Brandon; Kirk, Benjamin S.; Salazar, Giovanni; Droba, Justin

2016-01-01

An overview of the capabilities of the CHarring Ablator Response (CHAR) code is presented. CHAR is a one-, two-, and three-dimensional unstructured continuous Galerkin finite-element heat conduction and ablation solver with both direct and inverse modes. Additionally, CHAR includes a coupled linear thermoelastic solver for determination of internal stresses induced from the temperature field and surface loading. Background on the development process, governing equations, material models, discretization techniques, and numerical methods is provided. Special focus is put on the available boundary conditions including thermochemical ablation and contact interfaces, and example simulations are included. Finally, a discussion of ongoing development efforts is presented.

SURVIVAL OF SALMONELLA SPECIES IN RIVER WATER.

EPA Science Inventory

The survival of four Salmonella strains in river water microcosms was monitored using culturing techniques, direct counts, whole cell hybridization, scanning electron microscopy, and resuscitation techniques via the direct viable count method and flow cytrometry. Plate counts of...

Modern and Unconventional Approaches to Karst Hydrogeology

NASA Astrophysics Data System (ADS)

Sukop, M. C.

2017-12-01

Karst hydrogeology is frequently approached from a hydrograph/statistical perspective where precipitation/recharge inputs are converted to output hydrographs and the conversion process reflects the hydrology of the system. Karst catchments show hydrological response to short-term meteorological events and to long-term variation of large-scale atmospheric circulation. Modern approaches to analysis of these data include, for example, multiresolution wavelet techniques applied to understand relations between karst discharge and climate fields. Much less effort has been directed towards direct simulation of flow fields and transport phenomena in karst settings. This is primarily due to the lack of information on the detailed physical geometry of most karst systems. New mapping, sampling, and modeling techniques are beginning to enable direct simulation of flow and transport. A Conduit Flow Process (CFP) add-on to the USGS ModFlow model became available in 2007. FEFLOW and similar models are able to represent flows in individual conduits. Lattice Boltzmann models have also been applied to flow modeling in karst systems. Regarding quantitative measurement of karst system geometry, at scales to 0.1 m, X-ray computed tomography enables good detection of detailed (sub-millimeter) pore space in karstic rocks. Three-dimensional printing allows reconstruction of fragile high porosity rocks, and surrogate samples generated this way can then be subjected to laboratory testing. Borehole scales can be accessed with high-resolution ( 0.001 m) Digital Optical Borehole Imaging technologies and can provide virtual samples more representative of the true nature of karst aquifers than can obtained from coring. Subsequent extrapolation of such samples can generate three-dimensional models suitable for direct modeling of flow and transport. Finally, new cave mapping techniques are beginning to provide information than can be applied to direct simulation of flow. Due to flow rates and cave diameter, very high Reynolds number flows may be encountered.

Non-destructive evaluation of laboratory scale hydraulic fracturing using acoustic emission

NASA Astrophysics Data System (ADS)

Hampton, Jesse Clay

The primary objective of this research is to develop techniques to characterize hydraulic fractures and fracturing processes using acoustic emission monitoring based on laboratory scale hydraulic fracturing experiments. Individual microcrack AE source characterization is performed to understand the failure mechanisms associated with small failures along pre-existing discontinuities and grain boundaries. Individual microcrack analysis methods include moment tensor inversion techniques to elucidate the mode of failure, crack slip and crack normal direction vectors, and relative volumetric deformation of an individual microcrack. Differentiation between individual microcrack analysis and AE cloud based techniques is studied in efforts to refine discrete fracture network (DFN) creation and regional damage quantification of densely fractured media. Regional damage estimations from combinations of individual microcrack analyses and AE cloud density plotting are used to investigate the usefulness of weighting cloud based AE analysis techniques with microcrack source data. Two granite types were used in several sample configurations including multi-block systems. Laboratory hydraulic fracturing was performed with sample sizes ranging from 15 x 15 x 25 cm3 to 30 x 30 x 25 cm 3 in both unconfined and true-triaxially confined stress states using different types of materials. Hydraulic fracture testing in rock block systems containing a large natural fracture was investigated in terms of AE response throughout fracture interactions. Investigations of differing scale analyses showed the usefulness of individual microcrack characterization as well as DFN and cloud based techniques. Individual microcrack characterization weighting cloud based techniques correlated well with post-test damage evaluations.

Influence of bicortical techniques in internal connection placed in premaxillary area by 3D finite element analysis.

PubMed

Verri, Fellippo Ramos; Cruz, Ronaldo Silva; Lemos, Cleidiel Aparecido Araújo; de Souza Batista, Victor Eduardo; Almeida, Daniel Augusto Faria; Verri, Ana Caroline Gonçales; Pellizzer, Eduardo Piza

2017-02-01

The aim of study was to evaluate the stress distribution in implant-supported prostheses and peri-implant bone using internal hexagon (IH) implants in the premaxillary area, varying surgical techniques (conventional, bicortical and bicortical in association with nasal floor elevation), and loading directions (0°, 30° and 60°) by three-dimensional (3D) finite element analysis. Three models were designed with Invesalius, Rhinoceros 3D and Solidworks software. Each model contained a bone block of the premaxillary area including an implant (IH, Ø4 × 10 mm) supporting a metal-ceramic crown. 178 N was applied in different inclinations (0°, 30°, 60°). The results were analyzed by von Mises, maximum principal stress, microstrain and displacement maps including ANOVA statistical test for some situations. Von Mises maps of implant, screws and abutment showed increase of stress concentration as increased loading inclination. Bicortical techniques showed reduction in implant apical area and in the head of fixation screws. Bicortical techniques showed slight increase stress in cortical bone in the maximum principal stress and microstrain maps under 60° loading. No differences in bone tissue regarding surgical techniques were observed. As conclusion, non-axial loads increased stress concentration in all maps. Bicortical techniques showed lower stress for implant and screw; however, there was slightly higher stress on cortical bone only under loads of higher inclinations (60°).

Further Development of Rotating Rake Mode Measurement Data Analysis

NASA Technical Reports Server (NTRS)

Dahl, Milo D.; Hixon, Ray; Sutliff, Daniel L.

2013-01-01

The Rotating Rake mode measurement system was designed to measure acoustic duct modes generated by a fan stage. After analysis of the measured data, the mode amplitudes and phases were quantified. For low-speed fans within axisymmetric ducts, mode power levels computed from rotating rake measured data would agree with the far-field power levels on a tone by tone basis. However, this agreement required that the sound from the noise sources within the duct propagated outward from the duct exit without reflection at the exit and previous studies suggested conditions could exist where significant reflections could occur. To directly measure the modes propagating in both directions within a duct, a second rake was mounted to the rotating system with an offset in both the axial and the azimuthal directions. The rotating rake data analysis technique was extended to include the data measured by the second rake. The analysis resulted in a set of circumferential mode levels at each of the two rake microphone locations. Radial basis functions were then least-squares fit to this data to obtain the radial mode amplitudes for the modes propagating in both directions within the duct. The fit equations were also modified to allow evanescent mode amplitudes to be computed. This extension of the rotating rake data analysis technique was tested using simulated data, numerical code produced data, and preliminary in-duct measured data.

Improving the accuracy of effect-directed analysis: the role of bioavailability.

PubMed

You, Jing; Li, Huizhen

2017-12-13

Aquatic ecosystems have been suffering from contamination by multiple stressors. Traditional chemical-based risk assessment usually fails to explain the toxicity contributions from contaminants that are not regularly monitored or that have an unknown identity. Diagnosing the causes of noted adverse outcomes in the environment is of great importance in ecological risk assessment and in this regard effect-directed analysis (EDA) has been designed to fulfill this purpose. The EDA approach is now increasingly used in aquatic risk assessment owing to its specialty in achieving effect-directed nontarget analysis; however, a lack of environmental relevance makes conventional EDA less favorable. In particular, ignoring the bioavailability in EDA may cause a biased and even erroneous identification of causative toxicants in a mixture. Taking bioavailability into consideration is therefore of great importance to improve the accuracy of EDA diagnosis. The present article reviews the current status and applications of EDA practices that incorporate bioavailability. The use of biological samples is the most obvious way to include bioavailability into EDA applications, but its development is limited due to the small sample size and lack of evidence for metabolizable compounds. Bioavailability/bioaccessibility-based extraction (bioaccessibility-directed and partitioning-based extraction) and passive-dosing techniques are recommended to be used to integrate bioavailability into EDA diagnosis in abiotic samples. Lastly, the future perspectives of expanding and standardizing the use of biological samples and bioavailability-based techniques in EDA are discussed.

A modified transcondylar screw to accommodate anatomical skull base variations.

PubMed

Ghaly, R F; Lissounov, A

2017-01-01

Occipitocervical instability may be attributed to congenital, bony/ligamentous abnormalities, trauma, neoplasm, degenerative bone disease, and failed atlantoaxial fixation. Indications for occipitocervical fixation include the prevention of disabling pain, cranial nerve dysfunction, paralysis, or even sudden death. The screw trajectory for the modified transcondylar screw (mTCS) is optimally planned utilizing a three-dimensional skull reconstructed image. The modified mTCS technique is helpful where there is a loss of bone, such as after prior suboccipital craniotomy and/or an inadequate occipital condyle. The new proposed technique is similar to the classical transcondylar screw placement but follows a deeper course along the bony lip of foramen magnum toward clivus from a dorsolateral approach. The modified mTCS technique allows for direct visualization and, therefore, helps to avoid damage to the hypoglossal nerve and lateral aspect of brain stem.

Percutaneous Portal Vein Access and Transhepatic Tract Hemostasis

PubMed Central

Saad, Wael E. A.; Madoff, David C.

2012-01-01

Percutaneous portal vein interventions require minimally invasive access to the portal venous system. Common approaches to the portal vein include transjugular hepatic vein to portal vein access and direct transhepatic portal vein access. A major concern of the transhepatic route is the risk of postprocedural bleeding, which is increased when patients are anticoagulated or receiving pharmaceutical thrombolytic therapy. Thus percutaneous portal vein access and subsequent closure are important technical parts of percutaneous portal vein procedures. At present, various techniques have been used for either portal access or subsequent transhepatic tract closure and hemostasis. Regardless of the method used, meticulous technique is required to achieve the overall safety and effectiveness of portal venous procedures. This article reviews the various techniques of percutaneous transhepatic portal vein access and the various closure and hemostatic methods used to reduce the risk of postprocedural bleeding. PMID:23729976

Enhanced sampling techniques in biomolecular simulations.

PubMed

Spiwok, Vojtech; Sucur, Zoran; Hosek, Petr

2015-11-01

Biomolecular simulations are routinely used in biochemistry and molecular biology research; however, they often fail to match expectations of their impact on pharmaceutical and biotech industry. This is caused by the fact that a vast amount of computer time is required to simulate short episodes from the life of biomolecules. Several approaches have been developed to overcome this obstacle, including application of massively parallel and special purpose computers or non-conventional hardware. Methodological approaches are represented by coarse-grained models and enhanced sampling techniques. These techniques can show how the studied system behaves in long time-scales on the basis of relatively short simulations. This review presents an overview of new simulation approaches, the theory behind enhanced sampling methods and success stories of their applications with a direct impact on biotechnology or drug design. Copyright © 2014 Elsevier Inc. All rights reserved.

[Development of a technique for recovering Giardia cysts and Cryptosporidium oocysts from fresh vegetables].

PubMed

Di Benedetto, M A; Di Piazza, F; Oliveri, R; Cerame, G; Valenti, R; Firenze, A

2006-01-01

Techniques described for recovering Giardia and Cryptosporidium (oo)cysts from fruit and vegetables are generally inadequate and present variable recovery efficience and elevated costs. The aim of our study was to evaluate the recovery efficiency of a simple and economic technique to apply either to berry vegetables, like tomatoes and peppers, or to large leave vegetables, like lettuce and chicory. The method include contamination and further elution of the vegetables. Then sedimentation of (oo)cysts by centrifugation of the eluate of vegetables and their visualization by means of direct immunofluorescence. The higher recovery values for both protozoa were obtained in large leave vegetables with mean data above 70% for Giardia and 76% for Cryptosporidium, whereas the values observed in the berry vegetables were above 43% for Giardia and above 37% for Cryptosporidium on average.

Comparison of stromal hydration techniques for clear corneal cataract incisions: conventional hydration versus anterior stromal pocket hydration.

PubMed

Mifflin, Mark D; Kinard, Krista; Neuffer, Marcus C

2012-06-01

Anterior stromal pocket hydration was compared with conventional hydration for preventing wound leak after 2.8 mm uniplanar clear corneal incisions (CCIs) in patients having routine cataract surgery. Conventional hydration involves hydration of the lateral walls of the main incision with visible whitening of the stroma. The anterior stromal pocket hydration technique involves creation of an additional supraincisional stromal pocket overlying the main incision, which is then hydrated instead of the main incision. Sixty-six eyes of 48 patients were included in the data analysis with 33 assigned to each study group. The anterior stromal pocket hydration technique was significantly better than conventional hydration in preventing wound leak due to direct pressure on the posterior lip of the incision. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Space Shuttle propulsion parameter estimation using optimal estimation techniques

NASA Technical Reports Server (NTRS)

1983-01-01

This fourth monthly progress report again contains corrections and additions to the previously submitted reports. The additions include a simplified SRB model that is directly incorporated into the estimation algorithm and provides the required partial derivatives. The resulting partial derivatives are analytical rather than numerical as would be the case using the SOBER routines. The filter and smoother routine developments have continued. These routines are being checked out.

Single-neuron identification of chemical constituents, physiological changes, and metabolism using mass spectrometry.

PubMed

Zhu, Hongying; Zou, Guichang; Wang, Ning; Zhuang, Meihui; Xiong, Wei; Huang, Guangming

2017-03-07

The use of single-cell assays has emerged as a cutting-edge technique during the past decade. Although single-cell mass spectrometry (MS) has recently achieved remarkable results, deep biological insights have not yet been obtained, probably because of various technical issues, including the unavoidable use of matrices, the inability to maintain cell viability, low throughput because of sample pretreatment, and the lack of recordings of cell physiological activities from the same cell. In this study, we describe a patch clamp/MS-based platform that enables the sensitive, rapid, and in situ chemical profiling of single living neurons. This approach integrates modified patch clamp technique and modified MS measurements to directly collect and detect nanoliter-scale samples from the cytoplasm of single neurons in mice brain slices. Abundant possible cytoplasmic constituents were detected in a single neuron at a relatively fast rate, and over 50 metabolites were identified in this study. The advantages of direct, rapid, and in situ sampling and analysis enabled us to measure the biological activities of the cytoplasmic constituents in a single neuron, including comparing neuron types by cytoplasmic chemical constituents; observing changes in constituent concentrations as the physiological conditions, such as age, vary; and identifying the metabolic pathways of small molecules.

Bell's palsy and partial hypoglossal to facial nerve transfer: Case presentation and literature review

PubMed Central

Socolovsky, Mariano; Páez, Miguel Domínguez; Masi, Gilda Di; Molina, Gonzalo; Fernández, Eduardo

2012-01-01

Background: Idiopathic facial nerve palsy (Bell's palsy) is a very common condition that affects active population. Despite its generally benign course, a minority of patients can remain with permanent and severe sequelae, including facial palsy or dyskinesia. Hypoglossal to facial nerve anastomosis is rarely used to reinnervate the mimic muscle in these patients. In this paper, we present a case where a direct partial hypoglossal to facial nerve transfer was used to reinnervate the upper and lower face. We also discuss the indications of this procedure. Case Description: A 53-year-old woman presenting a spontaneous complete (House and Brackmann grade 6) facial palsy on her left side showed no improvement after 13 months of conservative treatment. Electromyography (EMG) showed complete denervation of the mimic muscles. A direct partial hypoglossal to facial nerve anastomosis was performed, including dissection of the facial nerve at the fallopian canal. One year after the procedure, the patient showed House and Brackmann grade 3 function in her affected face. Conclusions: Partial hypoglossal–facial anastomosis with intratemporal drilling of the facial nerve is a viable technique in the rare cases in which severe Bell's palsy does not recover spontaneously. Only carefully selected patients can really benefit from this technique. PMID:22574255

Single-neuron identification of chemical constituents, physiological changes, and metabolism using mass spectrometry

PubMed Central

Zhu, Hongying; Zou, Guichang; Wang, Ning; Zhuang, Meihui; Xiong, Wei; Huang, Guangming

2017-01-01

The use of single-cell assays has emerged as a cutting-edge technique during the past decade. Although single-cell mass spectrometry (MS) has recently achieved remarkable results, deep biological insights have not yet been obtained, probably because of various technical issues, including the unavoidable use of matrices, the inability to maintain cell viability, low throughput because of sample pretreatment, and the lack of recordings of cell physiological activities from the same cell. In this study, we describe a patch clamp/MS-based platform that enables the sensitive, rapid, and in situ chemical profiling of single living neurons. This approach integrates modified patch clamp technique and modified MS measurements to directly collect and detect nanoliter-scale samples from the cytoplasm of single neurons in mice brain slices. Abundant possible cytoplasmic constituents were detected in a single neuron at a relatively fast rate, and over 50 metabolites were identified in this study. The advantages of direct, rapid, and in situ sampling and analysis enabled us to measure the biological activities of the cytoplasmic constituents in a single neuron, including comparing neuron types by cytoplasmic chemical constituents; observing changes in constituent concentrations as the physiological conditions, such as age, vary; and identifying the metabolic pathways of small molecules. PMID:28223513

Robotic retroperitoneal partial nephrectomy: a step-by-step guide.

PubMed

Ghani, Khurshid R; Porter, James; Menon, Mani; Rogers, Craig

2014-08-01

To describe a step-by-step guide for successful implementation of the retroperitoneal approach to robotic partial nephrectomy (RPN) PATIENTS AND METHODS: The patient is placed in the flank position and the table fully flexed to increase the space between the 12th rib and iliac crest. Access to the retroperitoneal space is obtained using a balloon-dilating device. Ports include a 12-mm camera port, two 8-mm robotic ports and a 12-mm assistant port placed in the anterior axillary line cephalad to the anterior superior iliac spine, and 7-8 cm caudal to the ipsilateral robotic port. Positioning and port placement strategies for successful technique include: (i) Docking robot directly over the patient's head parallel to the spine; (ii) incision for camera port ≈1.9 cm (1 fingerbreadth) above the iliac crest, lateral to the triangle of Petit; (iii) Seldinger technique insertion of kidney-shaped balloon dilator into retroperitoneal space; (iv) Maximising distance between all ports; (v) Ensuring camera arm is placed in the outer part of the 'sweet spot'. The retroperitoneal approach to RPN permits direct access to the renal hilum, no need for bowel mobilisation and excellent visualisation of posteriorly located tumours. © 2014 The Authors. BJU International © 2014 BJU International.

Unhealthy food marketing to New Zealand children and adolescents through the internet.

PubMed

Vandevijvere, Stefanie; Sagar, Karuna; Kelly, Bridget; Swinburn, Boyd

2017-02-17

To assess the extent and nature of unhealthy food marketing to New Zealand children and adolescents through the internet. Internet traffic data for January 2014 was purchased from AC Nielsen to identify the most popular websites (n=110) among children and adolescents aged 6-17 years. In addition, websites (n=70) of food and beverage brands most frequently marketed to children through television, sports, magazines and Facebook were included. Marketing techniques and features on those websites were analysed. The extent of food marketing on popular non-food websites was low. A wide range of marketing techniques and features was, however, identified on food brand websites, including advercation (87%), viral marketing (64%), cookies (54%), free downloadable items (43%), promotional characters (39%), designated children's sections (19%) and advergaming (13%). Most techniques appeared more frequently on websites specifically targeting children and adolescents, than on other websites targeting the general public. Compared to traditional media, the internet allows food marketers to use engaging techniques to directly interact with children. While the range of marketing techniques and features identified on food brand websites was extensive, the most popular websites among children and adolescents were non-food related, and the extent of food marketing on those websites was found to be low. Additional assessment of food marketing to children through social and other digital media is recommended.

Carotid artery stenting: current and emerging options

PubMed Central

Morr, Simon; Lin, Ning; Siddiqui, Adnan H

2014-01-01

Carotid artery stenting technologies are rapidly evolving. Options for endovascular surgeons and interventionists who treat occlusive carotid disease continue to expand. We here present an update and overview of carotid stenting devices. Evidence supporting carotid stenting includes randomized controlled trials that compare endovascular stenting to open surgical endarterectomy. Carotid technologies addressed include the carotid stents themselves as well as adjunct neuroprotective devices. Aspects of stent technology include bare-metal versus covered stents, stent tapering, and free-cell area. Drug-eluting and cutting balloon indications are described. Embolization protection options and new direct carotid access strategies are reviewed. Adjunct technologies, such as intravascular ultrasound imaging and risk stratification algorithms, are discussed. Bare-metal and covered stents provide unique advantages and disadvantages. Stent tapering may allow for a more fitted contour to the caliber decrement between the common carotid and internal carotid arteries but also introduces new technical challenges. Studies regarding free-cell area are conflicting with respect to benefits and associated risk; clinical relevance of associated adverse effects associated with either type is unclear. Embolization protection strategies include distal filter protection and flow reversal. Though flow reversal was initially met with some skepticism, it has gained wider acceptance and may provide the advantage of not crossing the carotid lesion before protection is established. New direct carotid access techniques address difficult anatomy and incorporate sophisticated flow-reversal embolization protection techniques. Carotid stenting is a new and exciting field with rapidly advancing technologies. Embolization protection, low-risk deployment, and lesion assessment and stratification are active areas of research. Ample room remains for further innovations and developments. PMID:25349483

Imaging in syndesmotic injury: a systematic literature review.

PubMed

Krähenbühl, Nicola; Weinberg, Maxwell W; Davidson, Nathan P; Mills, Megan K; Hintermann, Beat; Saltzman, Charles L; Barg, Alexej

2018-05-01

To give a systematic overview of current diagnostic imaging options for assessment of the distal tibio-fibular syndesmosis. A systematic literature search across the following sources was performed: PubMed, ScienceDirect, Google Scholar, and SpringerLink. Forty-two articles were included and subdivided into three groups: group one consists of studies using conventional radiographs (22 articles), group two includes studies using computed tomography (CT) scans (15 articles), and group three comprises studies using magnet resonance imaging (MRI, 9 articles).The following data were extracted: imaging modality, measurement method, number of participants and ankles included, average age of participants, sensitivity, specificity, and accuracy of the measurement technique. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was used to assess the methodological quality. The three most common techniques used for assessment of the syndesmosis in conventional radiographs are the tibio-fibular clear space (TFCS), the tibio-fibular overlap (TFO), and the medial clear space (MCS). Regarding CT scans, the tibio-fibular width (axial images) was most commonly used. Most of the MRI studies used direct assessment of syndesmotic integrity. Overall, the included studies show low probability of bias and are applicable in daily practice. Conventional radiographs cannot predict syndesmotic injuries reliably. CT scans outperform plain radiographs in detecting syndesmotic mal-reduction. Additionally, the syndesmotic interval can be assessed in greater detail by CT. MRI measurements achieve a sensitivity and specificity of nearly 100%; however, correlating MRI findings with patients' complaints is difficult, and utility with subtle syndesmotic instability needs further investigation. Overall, the methodological quality of these studies was satisfactory.

Comparison of computer assisted surgery with conventional technique for treatment of abaxial distal phalanx fractures in horses: an in vitro study.

PubMed

Rossol, Melanie; Gygax, Diego; Andritzky-Waas, Juliane; Zheng, Guoyan; Lischer, Christoph J; Zhang, Xuan; Auer, Joerg A

2008-01-01

To (1) evaluate and compare computer-assisted surgery (CAS) with conventional screw insertion (conventional osteosynthesis [COS]) for treatment of equine abaxial distal phalanx fractures; (2) compare planned screw position with actual postoperative position; and (3) determine preferred screw insertion direction. Experimental study. Cadaveric equine limbs (n=32). In 8 specimens each, a 4.5 mm cortex bone screw was inserted in lag fashion in dorsopalmar (plantar) direction using CAS or COS. In 2 other groups of 8, the screws were inserted in opposite direction. Precision of CAS was determined by comparison of planned and actual screw position. Preferred screw direction was also assessed for CAS and COS. In 4 of 6 direct comparisons, screw positioning was significantly better with CAS. Results of precision analysis for screw position were similar to studies published in human medicine. None of evaluated criteria identified a preferred direction for screw insertion. For abaxial fractures of the distal phalanx, superior precision in screw position is achieved with CAS technique compared with COS technique. Abaxial fractures of the distal phalanx lend themselves to computer-assisted implantation of 1 screw in a dorsopalmar (plantar) direction. Because of the complex anatomic relationships, and our results, we discourage use of COS technique for repair of this fracture type.

Development of Methodologies, Metrics, and Tools for Investigating Human-Robot Interaction in Space Robotics

NASA Technical Reports Server (NTRS)

Ezer, Neta; Zumbado, Jennifer Rochlis; Sandor, Aniko; Boyer, Jennifer

2011-01-01

Human-robot systems are expected to have a central role in future space exploration missions that extend beyond low-earth orbit [1]. As part of a directed research project funded by NASA s Human Research Program (HRP), researchers at the Johnson Space Center have started to use a variety of techniques, including literature reviews, case studies, knowledge capture, field studies, and experiments to understand critical human-robot interaction (HRI) variables for current and future systems. Activities accomplished to date include observations of the International Space Station s Special Purpose Dexterous Manipulator (SPDM), Robonaut, and Space Exploration Vehicle (SEV), as well as interviews with robotics trainers, robot operators, and developers of gesture interfaces. A survey of methods and metrics used in HRI was completed to identify those most applicable to space robotics. These methods and metrics included techniques and tools associated with task performance, the quantification of human-robot interactions and communication, usability, human workload, and situation awareness. The need for more research in areas such as natural interfaces, compensations for loss of signal and poor video quality, psycho-physiological feedback, and common HRI testbeds were identified. The initial findings from these activities and planned future research are discussed. Human-robot systems are expected to have a central role in future space exploration missions that extend beyond low-earth orbit [1]. As part of a directed research project funded by NASA s Human Research Program (HRP), researchers at the Johnson Space Center have started to use a variety of techniques, including literature reviews, case studies, knowledge capture, field studies, and experiments to understand critical human-robot interaction (HRI) variables for current and future systems. Activities accomplished to date include observations of the International Space Station s Special Purpose Dexterous Manipulator (SPDM), Robonaut, and Space Exploration Vehicle (SEV), as well as interviews with robotics trainers, robot operators, and developers of gesture interfaces. A survey of methods and metrics used in HRI was completed to identify those most applicable to space robotics. These methods and metrics included techniques and tools associated with task performance, the quantification of human-robot interactions and communication, usability, human workload, and situation awareness. The need for more research in areas such as natural interfaces, compensations for loss of signal and poor video quality, psycho-physiological feedback, and common HRI testbeds were identified. The initial findings from these activities and planned future research are discussed.

Efficient morse decompositions of vector fields.

PubMed

Chen, Guoning; Mischaikow, Konstantin; Laramee, Robert S; Zhang, Eugene

2008-01-01

Existing topology-based vector field analysis techniques rely on the ability to extract the individual trajectories such as fixed points, periodic orbits, and separatrices that are sensitive to noise and errors introduced by simulation and interpolation. This can make such vector field analysis unsuitable for rigorous interpretations. We advocate the use of Morse decompositions, which are robust with respect to perturbations, to encode the topological structures of a vector field in the form of a directed graph, called a Morse connection graph (MCG). While an MCG exists for every vector field, it need not be unique. Previous techniques for computing MCG's, while fast, are overly conservative and usually results in MCG's that are too coarse to be useful for the applications. To address this issue, we present a new technique for performing Morse decomposition based on the concept of tau-maps, which typically provides finer MCG's than existing techniques. Furthermore, the choice of tau provides a natural tradeoff between the fineness of the MCG's and the computational costs. We provide efficient implementations of Morse decomposition based on tau-maps, which include the use of forward and backward mapping techniques and an adaptive approach in constructing better approximations of the images of the triangles in the meshes used for simulation.. Furthermore, we propose the use of spatial tau-maps in addition to the original temporal tau-maps. These techniques provide additional trade-offs between the quality of the MCGs and the speed of computation. We demonstrate the utility of our technique with various examples in the plane and on surfaces including engine simulation data sets.

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

Techniques for Type I Collagen Organization

NASA Astrophysics Data System (ADS)

Anderson-Jackson, LaTecia Diamond

Tissue Engineering is a process in which cells, engineering, and material methods are used in amalgamation to improve biological functions. The purpose of tissue engineering is to develop alternative solutions to treat or cure tissues and organs that have been severely altered or damaged by diseases, congenital defects, trauma, or cancer. One of the most common and most promising biological materials for tissue engineering to develop scaffolds is Type I collagen. A major challenge in biomedical research is aligning Type I collagen to mimic biological structures, such as ligaments, tendons, bones, and other hierarchal aligned structures within the human body. The intent of this research is to examine possible techniques for organizing Type I collagen and to assess which of the techniques is effective for potential biological applications. The techniques used in this research to organize collagen are soft lithography with solution-assisted sonication embossing, directional freezing, and direct poling. The final concentration used for both soft lithography with solution-assisted sonication embossing and direct poling was 1 mg/ml, whereas for directional freezing the final concentration varied between 4mg/ml, 2mg/ml, and 1 mg/ml. These techniques were characterized using the Atomic Force Microscope (AFM) and Helium Ion Microscope (HIM). In this study, we have found that out of the three techniques, the soft lithography and directional freezing techniques have been successful in organizing collagen in a particular pattern, but not alignment. We concluded alignment may be dependent on the pH of collagen and the amount of acetic acid used in collagen solution. However, experiments are still being conducted to optimize all three techniques to align collagen in a unidirectional arrangement.

Success of Intubation Rescue Techniques after Failed Direct Laryngoscopy in Adults: A Retrospective Comparative Analysis from the Multicenter Perioperative Outcomes Group.

PubMed

Aziz, Michael F; Brambrink, Ansgar M; Healy, David W; Willett, Amy Wen; Shanks, Amy; Tremper, Tyler; Jameson, Leslie; Ragheb, Jacqueline; Biggs, Daniel A; Paganelli, William C; Rao, Janavi; Epps, Jerry L; Colquhoun, Douglas A; Bakke, Patrick; Kheterpal, Sachin

2016-10-01

Multiple attempts at tracheal intubation are associated with mortality, and successful rescue requires a structured plan. However, there remains a paucity of data to guide the choice of intubation rescue technique after failed initial direct laryngoscopy. The authors studied a large perioperative database to determine success rates for commonly used intubation rescue techniques. Using a retrospective, observational, comparative design, the authors analyzed records from seven academic centers within the Multicenter Perioperative Outcomes Group between 2004 and 2013. The primary outcome was the comparative success rate for five commonly used techniques to achieve successful tracheal intubation after failed direct laryngoscopy: (1) video laryngoscopy, (2) flexible fiberoptic intubation, (3) supraglottic airway as part of an exchange technique, (4) optical stylet, and (5) lighted stylet. A total of 346,861 cases were identified that involved attempted tracheal intubation. A total of 1,009 anesthesia providers managed 1,427 cases of failed direct laryngoscopy followed by subsequent intubation attempts (n = 1,619) that employed one of the five studied intubation rescue techniques. The use of video laryngoscopy resulted in a significantly higher success rate (92%; 95% CI, 90 to 93) than other techniques: supraglottic airway conduit (78%; 95% CI, 68 to 86), flexible bronchoscopic intubation (78%; 95% CI, 71 to 83), lighted stylet (77%; 95% CI, 69 to 83), and optical stylet (67%; 95% CI, 35 to 88). Providers most frequently choose video laryngoscopy (predominantly GlideScope [Verathon, USA]) to rescue failed direct laryngoscopy (1,122/1,619; 69%), and its use has increased during the study period. Video laryngoscopy is associated with a high rescue intubation success rate and is more commonly used than other rescue techniques.

A review of earth abundant ZnO-based materials for thermoelectric and photovoltaic applications

NASA Astrophysics Data System (ADS)

Wang, Yang; Zhou, Chuanle; Elquist, Aline M.; Ghods, Amirhossein; Saravade, Vishal G.; Lu, Na; Ferguson, Ian

2018-02-01

Zinc oxide (ZnO) is an earth abundant wide bandgap semiconductor of great interest in the recent years. ZnO has many unique properties, such as non-toxic, large direct bandgap, high exciton binding energy, high transparency in visible and infrared spectrum, large Seebeck coefficient, high thermal stability, high electron diffusivity, high electron mobility, and availability of various nanostructures, making it a promising material for many applications. The growth techniques of ZnO is reviewed in this work, including sputtering, PLD, MOCVD and MBE techniques, focusing on the crystalline quality, electrical and optical properties. The problem with p-type doping ZnO is also discussed, and the method to improve p-type doping efficiency is reviewed. This paper also summarizes the current state of art of ZnO in thermoelectric and photovoltaic applications, including the key parameters, different device structures, and future development.

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

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.

Role of Molecular Biology in Cancer Treatment: A Review Article.

PubMed

Imran, Aman; Qamar, Hafiza Yasara; Ali, Qurban; Naeem, Hafsa; Riaz, Mariam; Amin, Saima; Kanwal, Naila; Ali, Fawad; Sabar, Muhammad Farooq; Nasir, Idrees Ahmad

2017-11-01

Cancer is a genetic disease and mainly arises due to a number of reasons include activation of onco-genes, malfunction of tumor suppressor genes or mutagenesis due to external factors. This article was written from the data collected from PubMed, Nature, Science Direct, Springer and Elsevier groups of journals. Oncogenes are deregulated form of normal proto-oncogenes required for cell division, differentiation and regulation. The conversion of proto-oncogene to oncogene is caused due to translocation, rearrangement of chromosomes or mutation in gene due to addition, deletion, duplication or viral infection. These oncogenes are targeted by drugs or RNAi system to prevent proliferation of cancerous cells. There have been developed different techniques of molecular biology used to diagnose and treat cancer, including retroviral therapy, silencing of oncogenes and mutations in tumor suppressor genes. Among all the techniques used, RNAi, zinc finger nucleases and CRISPR hold a brighter future towards creating a Cancer Free World.

Measurement of stiffness of standing trees and felled logs using acoustics: A review.

PubMed

Legg, Mathew; Bradley, Stuart

2016-02-01

This paper provides a review on the use of acoustics to measure stiffness of standing trees, stems, and logs. An outline is given of the properties of wood and how these are related to stiffness and acoustic velocity throughout the tree. Factors are described that influence the speed of sound in wood, including the different types of acoustic waves which propagate in tree stems and lumber. Acoustic tools and techniques that have been used to measure the stiffness of wood are reviewed. The reasons for a systematic difference between direct and acoustic measurements of stiffness for standing trees, and methods for correction, are discussed. Other techniques, which have been used in addition to acoustics to try to improve stiffness measurements, are also briefly described. Also reviewed are studies which have used acoustic tools to investigate factors that influence the stiffness of trees. These factors include different silvicultural practices, geographic and environmental conditions, and genetics.

Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques - a review.

PubMed

Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan; Ondra, Peter; Válka, Ivo; Ševčík, Juraj; Chrastina, Jan; Maier, Vítězslav

2015-05-18

Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry. Copyright © 2015 Elsevier B.V. All rights reserved.

Stasis Dermatitis: Pathophysiology, Evaluation, and Management.

PubMed

Sundaresan, Swaminathan; Migden, Michael R; Silapunt, Sirunya

2017-06-01

Stasis dermatitis commonly occurs in older age. It is caused by venous hypertension resulting from retrograde flow due to incompetent venous valves, valve destruction, or obstruction of the venous system. Further tissue changes arise from an inflammatory process mediated by metalloproteinases, which are up-regulated by ferric ion from extravasated red blood cells. Stasis dermatitis presents initially as poorly demarcated erythematous plaques of the lower legs bilaterally, classically involving the medial malleolus. It is one of the spectrum of cutaneous findings that may result from chronic venous insufficiency. Its mimics include cellulitis, contact dermatitis, and pigmented purpuric dermatoses. Duplex ultrasound is useful in demonstrating venous reflux when the clinical diagnosis of stasis dermatitis is inadequate. Conservative treatment involves the use of compression therapy directed at improving ambulatory venous pressure. Interventional therapy currently includes minimally invasive techniques such as endovenous thermal ablation and ultrasound-guided foam sclerotherapy, which have supplanted the use of open surgical techniques.

Cut set-based risk and reliability analysis for arbitrarily interconnected networks

DOEpatents

Wyss, Gregory D.

2000-01-01

Method for computing all-terminal reliability for arbitrarily interconnected networks such as the United States public switched telephone network. The method includes an efficient search algorithm to generate minimal cut sets for nonhierarchical networks directly from the network connectivity diagram. Efficiency of the search algorithm stems in part from its basis on only link failures. The method also includes a novel quantification scheme that likewise reduces computational effort associated with assessing network reliability based on traditional risk importance measures. Vast reductions in computational effort are realized since combinatorial expansion and subsequent Boolean reduction steps are eliminated through analysis of network segmentations using a technique of assuming node failures to occur on only one side of a break in the network, and repeating the technique for all minimal cut sets generated with the search algorithm. The method functions equally well for planar and non-planar networks.

Pancreatic trauma: demographics, diagnosis, and management.

PubMed

Stawicki, Stanislaw Peter; Schwab, C William

2008-12-01

Pancreatic injuries are rare, with penetrating mechanisms being causative in majority of cases. They can create major diagnostic and therapeutic challenges and require multiple diagnostic modalities, including multislice high-definition computed tomography, magnetic resonance cholangiopancreatography, endoscopic retrograde cholangiopancreatography, ultrasonography, and at times, surgery and direct visualization of the pancreas. Pancreatic trauma is frequently associated with duodenal and other severe vascular and visceral injuries. Mortality is high and usually related to the concomitant vascular injury. Surgical management of pancreatic and pancreatic-duodenal trauma is challenging, and multiple surgical approaches and techniques have been described, up to and including pancreatic damage control and later resection and reconstruction. Wide surgical drainage is a key to any surgical trauma technique and access for enteral nutrition, or occasionally parenteral nutrition, are important adjuncts. Morbidity associated with pancreatic trauma is high and can be quite severe. Treatment of pancreatic trauma-related complications often requires a combination of interventional, endoscopic, and surgical approaches.

SURVIVAL OF SALMONELLA SPECIES IN RIVER WATER

EPA Science Inventory

The survival of four Salmonella strains in river water microcosms was monitored by culturing techniques, direct counts, whole-cell hybridization, scanning electron microscopy, and resuscitation techniques via the direct viable count method and flow cytometry. Plate counts of bact...

Peritoneal dialysis technique success during the initial 90 days of therapy.

PubMed

Guest, Steven; Hayes, Andrew C; Story, Kenneth; Davis, Ira D

2012-01-01

Comparisons of technique success by peritoneal dialysis (PD) modality have typically excluded the initial 90 days of therapy. We analyzed a database of 51,469 new PD starts from 2004 to 2008 in the United States. The analysis concentrated on the initial 90 days of therapy to determine technique success and the impact of the continuous ambulatory PD (CAPD) and automated PD (APD) modalities. Overall, 13.3% of patients stopped PD within 90 days. Of patients starting directly on APD, 14.3% stopped PD within 90 days. Of patients starting on CAPD, 12.6% stopped PD within 90 days, and 63.4% changed to APD within 90 days. Only 3.3% of the latter patients failed to reach 90 days of therapy. By comparison, technique failure occurred in 28.8% of those initiating with and remaining on CAPD. We conclude that initial training to perform CAPD, with timely transfer to APD within the first 3 months, was associated with the greatest technique success at 90 days. The reasons for that success are unclear, and further research should be directed to determining factors responsible. It is possible that patients trained initially to CAPD but converted to APD have a greater understanding of the total therapy, which improves confidence. Those converted to APD may be more appreciative of the lifestyle benefits of APD, which translates into improved compliance; alternatively, technical factors associated with APD may be responsible. Those technical factors may include improved catheter function in the recumbent position during APD or the reduced infection risk associated with just 2 connect/disconnect procedures in APD compared with 8 in CAPD.

Endoscopic cubital tunnel release using the Hoffmann technique.

PubMed

Hoffmann, Reimer; Lubahn, John

2013-06-01

Endoscopic cubital tunnel release was originally described in 1989 by Tsai, and his technique has been modified by other surgeons including Mirza and Cobb. In 2006, Hoffmann and Siemionow described an endoscopic technique quite different from Tsai's original description. Instead of working from the "inside out," Hoffmann's technique is performed through an incision similar to that which would be used for an in situ release of the ulnar nerve. The main difference being that the nerve can be explored and decompressed 10 cm proximal and distal to the arcuate ligament as the surgeon looks down on the nerve and the surrounding tissues while viewing the anatomy through a camera attached to a soft tissue endoscope that is inserted in the wound. The arcuate (Osborne's) ligament is released under direct vision much like a standard in situ decompression. Using a blunt dissection instrument, a workspace is created proximally and distally to the cubital tunnel. Next an illuminated speculum is introduced, the nerve is directly visualized between 4 and 5 cm proximal and distal to the cubital tunnel, and potential compressive forearm fasciae or fibrous bands are released. Finally, a 15-cm, 30° soft tissue endoscope is introduced into the incision, and viewing the internal anatomy on a video monitor, the decompression continues using longer scissors. Any potential bleeding is controlled with a long bayonet bipolar cautery. The authors discuss indications, contraindications, and the surgical technique. Postoperative management and associated complications are also discussed. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Comparison of patient outcomes in periarticular and intraarticular local anaesthetic infiltration techniques in total knee arthroplasty.

PubMed

Perret, Michael; Fletcher, Philip; Firth, Laura; Yates, Piers

2015-07-31

The use of local infiltration analgesia in the setting of knee arthroplasty is well established. There are no studies to date which have directly compared differences in infiltration techniques. The purpose of this study is to establish if a difference in patient outcomes exists when the infiltrate is injected into the periarticular tissues or directly into the joint. One hundred and forty-two consecutive patients waitlisted for primary total knee arthroplasty were enrolled after primary exclusion criteria were applied. These included the following: allergy to study drugs, inability to receive spinal anaesthesia, and planned bilateral surgery. Patients were divided into two groups, a periarticular infiltration group (group A) and an intraarticular infiltration group (group B). Secondary exclusion criteria of regular opioid use, psychiatric illness, and serious medical comorbidity left a total of 47 patients in group A and 54 patients in group B. Both groups received a combination of 30 mg ketorolac, 500 μg of adrenaline, and 300 mg of ropivacaine, and normal saline. This was either injected into the periarticular tissues during surgery (group A) or intraarticularly after closure of the wound (group B). Primary outcome measures included opioid consumption during the first 24 h postoperatively and over the total admission, and visual analogue scales (VAS) on postoperative day 1 and at discharge. Secondary measures included Oxford Knee Score, knee flexion, length of stay, haemoglobin drop, and transfusion requirement. Ethics approval was granted by the hospital review board. The trial is registered in the Australian New Zealand Clinical Trials Registry, registration ACTRN12615000488505 . No statistically significant differences in postoperative analgesic use were observed between the two groups. However, there was a trend toward decreased postoperative patient-controlled analgesia use in the periarticular group (mean 53.1 vs 68.3 mg morphine equivalents; p = 0.093), as well as a statistically significant reduction in postoperative visual analogue pain scores. No statistically significant differences were observed for haemoglobin drop, range of motion, or pre- to 6-week postoperative Oxford Score difference. Our study is the first we are aware of to directly compare a periarticular to intraarticular injection technique when using local infiltration analgesia for total knee arthroplasty. Our results show no clear statistically significant benefit with either technique. The periarticular group showed a statistically significant reduction in postoperative VAS pain scores alongside a trend in that group toward reduced overall opioid use.

Thermal fatigue and oxidation data of superalloys including directionally solidified eutectics

NASA Technical Reports Server (NTRS)

Hill, V. L.; Humphreys, V. E.

1977-01-01

Thermal fatigue and oxidation data were obtained on 61 specimens, representing 15 discrete alloy compositions or fabricating techniques and three coating systems. Conventionally fabricated alloys included V57, MM 200, Rene 77, Rene 125, MM 246, MM 509, IN-738, IN-792 + Hf, and MM 200 + Hf. The directionally solidified alloys were MM 200, MM 200 single crystal, MM 200 bicrystal, cellular gamma/gamma' - delta) and lamellar gamma/gamma' - delta. The coatings systems included NiCrAlY on IN-738, In-792 + Hf, MM 200 DS, MM 200 DS single crystal, and cellular gamma/gamma' - delta and NiCrAlY/Pt on lamellar gamma/gamma' - delta. Crack initiation survival rates were recorded for all alloys, with and without coatings. All uncoated alloys, except MM 509, exhibited significant oxidation weight loss in 75,000 to 15,000 cycles. MM 509 specimens had weight losses only slightly higher than coated specimens through 7,500 cycles. All coated specimens had low weight loss.

Fringe pattern demodulation with a two-dimensional digital phase-locked loop algorithm.

PubMed

Gdeisat, Munther A; Burton, David R; Lalor, Michael J

2002-09-10

A novel technique called a two-dimensional digital phase-locked loop (DPLL) for fringe pattern demodulation is presented. This algorithm is more suitable for demodulation of fringe patterns with varying phase in two directions than the existing DPLL techniques that assume that the phase of the fringe patterns varies only in one direction. The two-dimensional DPLL technique assumes that the phase of a fringe pattern is continuous in both directions and takes advantage of the phase continuity; consequently, the algorithm has better noise performance than the existing DPLL schemes. The two-dimensional DPLL algorithm is also suitable for demodulation of fringe patterns with low sampling rates, and it outperforms the Fourier fringe analysis technique in this aspect.

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.