Gel spinning of silk tubes for tissue engineering

PubMed Central

Lovett, Michael; Cannizzaro, Christopher; Vunjak-Novakovic, Gordana; Kaplan, David L.

2011-01-01

Tubular vessels for tissue engineering are typically fabricated using a molding, dipping, or electrospinning technique. While these techniques provide some control over inner and outer diameters of the tube, they lack the ability to align the polymers or fibers of interest throughout the tube. This is an important aspect of biomaterial composite structure and function for mechanical and biological impact of tissue outcomes. We present a novel aqueous process system to spin tubes from biopolymers and proteins such as silk fibroin. Using silk as an example, this method of winding an aqueous solution around a reciprocating rotating mandrel offers substantial improvement in the control of the tube properties, specifically with regard to winding pattern, tube porosity, and composite features. Silk tube properties are further controlled via different post-spinning processing mechanisms such as methanol-treatment, air-drying, and lyophilization. This approach to tubular scaffold manufacture offers numerous tissue engineering applications such as complex composite biomaterial matrices, blood vessel grafts and nerve guides, among others. PMID:18801570

Parametric Study of High Frequency Pulse Detonation Tubes

NASA Technical Reports Server (NTRS)

Cutler, Anderw D.

2008-01-01

This paper describes development of high frequency pulse detonation tubes similar to a small pulse detonation engine (PDE). A high-speed valve injects a charge of a mixture of fuel and air at rates of up to 1000 Hz into a constant area tube closed at one end. The reactants detonate in the tube and the products exit as a pulsed jet. High frequency pressure transducers are used to monitor the pressure fluctuations in the device and thrust is measured with a balance. The effects of injection frequency, fuel and air flow rates, tube length, and injection location are considered. Both H2 and C2H4 fuels are considered. Optimum (maximum specific thrust) fuel-air compositions and resonant frequencies are identified. Results are compared to PDE calculations. Design rules are postulated and applications to aerodynamic flow control and propulsion are discussed.

Computer model of catalytic combustion/Stirling engine heater head

NASA Technical Reports Server (NTRS)

Chu, E. K.; Chang, R. L.; Tong, H.

1981-01-01

The basic Acurex HET code was modified to analyze specific problems for Stirling engine heater head applications. Specifically, the code can model: an adiabatic catalytic monolith reactor, an externally cooled catalytic cylindrical reactor/flat plate reactor, a coannular tube radiatively cooled reactor, and a monolithic reactor radiating to upstream and downstream heat exchangers.

The LabTube - a novel microfluidic platform for assay automation in laboratory centrifuges.

PubMed

Kloke, A; Fiebach, A R; Zhang, S; Drechsel, L; Niekrawietz, S; Hoehl, M M; Kneusel, R; Panthel, K; Steigert, J; von Stetten, F; Zengerle, R; Paust, N

2014-05-07

Assay automation is the key for successful transformation of modern biotechnology into routine workflows. Yet, it requires considerable investment in processing devices and auxiliary infrastructure, which is not cost-efficient for laboratories with low or medium sample throughput or point-of-care testing. To close this gap, we present the LabTube platform, which is based on assay specific disposable cartridges for processing in laboratory centrifuges. LabTube cartridges comprise interfaces for sample loading and downstream applications and fluidic unit operations for release of prestored reagents, mixing, and solid phase extraction. Process control is achieved by a centrifugally-actuated ballpen mechanism. To demonstrate the workflow and functionality of the LabTube platform, we show two LabTube automated sample preparation assays from laboratory routines: DNA extractions from whole blood and purification of His-tagged proteins. Equal DNA and protein yields were observed compared to manual reference runs, while LabTube automation could significantly reduce the hands-on-time to one minute per extraction.

40 CFR 428.10 - Applicability; description of the tire and inner tube plants subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the tire... Tire and Inner Tube Plants Subcategory § 428.10 Applicability; description of the tire and inner tube... pollutants resulting from the production of pneumatic tires and inner tubes in tire and inner tube plants...

Numerical and experimental investigation of bi-annulus heat exchanger for different alternative materials

NASA Astrophysics Data System (ADS)

Zeeshan, M.; Duggal, R.; Tated, M. K.; Singh, M.

2018-02-01

Heat exchangers are widely used in various energy-recovery applications. However, for specific applications where metallic tubes are subjected to various drawbacks i.e. cost, weight, corrosion etc. polymer materials are promising alternatives. In present study, various conventional as well as promising alternatives materials are chosen for investigation computationally. Experimentally, bi-annulus heat exchanger configuration is investigated for metallic materials. The simulations carried out conclude that the dimensionless temperature parameter for Cross-linked polypropylethylene (PEX) is greater than other polymers. It increases with increasing axial length of tube. The value for dimensionless temperature is higher for copper which is used as conventional tube material. Among different polymers highest temperature is observed for PEX followed by Low density polypropylene (LDPE), Polypropylene (PP) and Polyvinylidene fluoride (PVDF). For axial length up to 70mm approx. the temperature rises for PEX, LDPE is 28.3% and 26.4% respectively. However, temperature variation is same for PP and PVDF for same axial distance. This temperature variation is increased to 72.4%, 67.2%, 58.62% and 56.89% for PEX, LDPE, PP and PVDF respectively as axial distance variation reaches the end of pipe. The inner annulus temperature for PEX material at 10% length of tube is 28.3% of temperature achieved in copper tube which increases to 72.4% for full length of tube.

Novel approach based on one-tube nested PCR and a lateral flow strip for highly sensitive diagnosis of tuberculous meningitis.

PubMed

Sun, Yajuan; Chen, Jiajun; Li, Jia; Xu, Yawei; Jin, Hui; Xu, Na; Yin, Rui; Hu, Guohua

2017-01-01

Rapid and sensitive detection of Mycobacterium tuberculosis (M. Tb) in cerebrospinal fluid is crucial in the diagnosis of tuberculous meningitis (TBM), but conventional diagnostic technologies have limited sensitivity and specificity or are time-consuming. In this work, a novel, highly sensitive molecular diagnostic method, one-tube nested PCR-lateral flow strip test (OTNPCR-LFST), was developed for detecting M. tuberculosis. This one-tube nested PCR maintains the sensitivity of conventional two-step nested PCR and reduces both the chance of cross-contamination and the time required for analysis. The PCR product was detected by a lateral flow strip assay, which provided a basis for migration of the test to a point-of-care (POC) microfluidic format. The developed assay had an improved sensitivity compared with traditional PCR, and the limit of detection was up to 1 fg DNA isolated from M. tuberculosis. The assay was also specific for M. tuberculosis, and no cross-reactions were found in other non-target bacteria. The application of this technique to clinical samples was successfully evaluated, and OTNPCR-LFST showed 89% overall sensitivity and 100% specificity for TBM patients. This one-tube nested PCR-lateral flow strip assay is useful for detecting M. tuberculosis in TBM due to its rapidity, high sensitivity and simple manipulation.

Advantages of high-frequency Pulse-tube technology and its applications in infrared sensing

NASA Astrophysics Data System (ADS)

Arts, R.; Willems, D.; Mullié, J.; Benschop, T.

2016-05-01

The low-frequency pulse-tube cryocooler has been a workhorse for large heat lift applications. However, the highfrequency pulse tube has to date not seen the widespread use in tactical infrared applications that Stirling cryocoolers have had, despite significant advantages in terms of exported vibrations and lifetime. Thales Cryogenics has produced large series of high-frequency pulse-tube cryocoolers for non-infrared applications since 2005. However, the use of Thales pulse-tube cryocoolers for infrared sensing has to date largely been limited to high-end space applications. In this paper, the performances of existing available off-the-shelf pulse-tube cryocoolers are examined versus typical tactical infrared requirements. A comparison is made on efficiency, power density, reliability, and cost. An outlook is given on future developments that could bring the pulse-tube into the mainstream for tactical infrared applications.

The effect of an artificially lengthened vocal tract on estimated glottal contact quotient in untrained male voices.

PubMed

Gaskill, Christopher S; Erickson, Molly L

2010-01-01

The use of hard-walled narrow tubes, often called resonance tubes, for the purpose of voice therapy and voice training has a historical precedent and some theoretical support, but the mechanism of any potential benefit from the application of this technique is not well understood. Fifteen vocally untrained male participants produced a series of spoken /a/ vowels at a modal pitch and constant loudness, before and after a minute of repeated phonation into a 50-cm hard-walled glass tube at the same pitch and loudness targets. Electroglottography was used to measure the glottal contact quotient (CQ) during each phase of the experiment. Single-subject analysis revealed statistically significant changes in CQ during tube phonation, but with no discernable pattern across the 15 participants. These results indicate that the use of resonance tubes can have a distinct effect on glottal closure, but the mechanism behind this change remains unclear. The implication is that vocal loading techniques such as this need to be studied further with specific attention paid to the underlying mechanism of any measured changes in glottal behavior, and especially to the role of instruction and feedback in the therapeutic and pedagogical application of these techniques. Copyright 2010 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Effects of an artificially lengthened vocal tract on the glottal closed quotient in untrained male voices

NASA Astrophysics Data System (ADS)

Gaskill, Christopher Somers

The use of hard-walled narrow tubes, often called resonance tubes, for the purpose of voice therapy and voice training has a historical precedent and some theoretical support, but the mechanism of any potential benefit from the application of this technique has remained poorly understood. Fifteen vocally untrained male participants produced a series of spoken /a / vowels at a modal pitch and constant loudness, followed by a minute of repeated phonation into a hard-walled glass tube at the same pitch and loudness targets. The tube parameters and tube phonation task criteria were selected according to theoretical calculations predicting an increase in the acoustic load such that phonation would occur under conditions of near-maximum inertive reactance. Following tube phonation, each participant repeated a similar series of spoken /a/ vowels. Electroglottography (EGG) was used to measure the glottal closed quotient (CQ) during each phase of the experiment. A single-subject, multiple-baseline design with direct replication across subjects was used to identify any changes in CQ across the phases of the experiment. Single-subject analysis using the method of Statistical Process Control (SPC) revealed statistically significant changes in CQ during tube phonation, but with no discernable pattern across the 15 participants. These results indicate that the use of resonance tubes can have a distinct effect on glottal closure, but the mechanism behind this change remains unclear. The implication is that vocal loading techniques such as this need to be studied further with specific attention paid to the underlying mechanism of any measured changes in glottal behavior, and especially to the role of instruction and feedback in the therapeutic and pedagogical application of these techniques.

High performance TWT development for the microwave power module

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

Whaley, D.R.; Armstrong, C.M.; Groshart, G.

1996-12-31

Northrop Grumman`s ongoing development of microwave power modules (MPM) provides microwave power at various power levels, frequencies, and bandwidths for a variety of applications. Present day requirements for the vacuum power booster traveling wave tubes of the microwave power module are becoming increasingly more demanding, necessitating the need for further enhancement of tube performance. The MPM development program at Northrop Grumman is designed specifically to meet this need by construction and test of a series of new tubes aimed at verifying computation and reaching high efficiency design goals. Tubes under test incorporate several different helix designs, as well as varyingmore » electron gun and magnetic confinement configurations. Current efforts also include further development of state-of-the-art TWT modeling and computational methods at Northrop Grumman incorporating new, more accurate models into existing design tools and developing new tools to be used in all aspects of traveling wave tube design. Current status of the Northrop Grumman MPM TWT development program will be presented.« less

Development of Pulse Tube Cryocoolers at SITP for Space Application

NASA Astrophysics Data System (ADS)

Zhang, Ankuo; Wu, Yinong; Liu, Shaoshuai; Yu, Huiqin; Yang, Baoyu

2018-05-01

Over the last 10 years, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, has developed very high-efficiency pulse tube cryocoolers (PTCs) for aerospace applications. These PTCs can provide cooling power from milliwatt scale to tens of watts over a range of temperatures from 30 to 170 K and can be used to cool a variety of detectors in space applications (such as quantum interference devices, radiometers and ocean color sensors) that must operate at a specific cryogenic temperature to increase the signal-to-noise ratio, sensitivity and optical resolution. This paper reviews the development of single-stage PTCs over a range of weights from 1.6 to 12 kg that offer cooling powers at the cold temperature range from 40 to 170 K. In addition, a two-stage 30 K-PTC is under development.

Dual resin bonded joints in polyetheretherketone (PEEK) matrix composites

NASA Astrophysics Data System (ADS)

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

1993-04-01

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

Novel approach based on one-tube nested PCR and a lateral flow strip for highly sensitive diagnosis of tuberculous meningitis

PubMed Central

Sun, Yajuan; Chen, Jiajun; Li, Jia; Xu, Yawei; Jin, Hui; Xu, Na; Yin, Rui

2017-01-01

Rapid and sensitive detection of Mycobacterium tuberculosis (M. Tb) in cerebrospinal fluid is crucial in the diagnosis of tuberculous meningitis (TBM), but conventional diagnostic technologies have limited sensitivity and specificity or are time-consuming. In this work, a novel, highly sensitive molecular diagnostic method, one-tube nested PCR-lateral flow strip test (OTNPCR-LFST), was developed for detecting M. tuberculosis. This one-tube nested PCR maintains the sensitivity of conventional two-step nested PCR and reduces both the chance of cross-contamination and the time required for analysis. The PCR product was detected by a lateral flow strip assay, which provided a basis for migration of the test to a point-of-care (POC) microfluidic format. The developed assay had an improved sensitivity compared with traditional PCR, and the limit of detection was up to 1 fg DNA isolated from M. tuberculosis. The assay was also specific for M. tuberculosis, and no cross-reactions were found in other non-target bacteria. The application of this technique to clinical samples was successfully evaluated, and OTNPCR-LFST showed 89% overall sensitivity and 100% specificity for TBM patients. This one-tube nested PCR-lateral flow strip assay is useful for detecting M. tuberculosis in TBM due to its rapidity, high sensitivity and simple manipulation. PMID:29084241

Recent developments in shock tube research; Proceedings of the Ninth International Symposium, Stanford University, Stanford, Calif., July 16-19, 1973

NASA Technical Reports Server (NTRS)

Bershader, D. (Editor); Griffith, W.

1973-01-01

Recent advances in shock tube research are described in papers dealing with the design and performance features of new devices as well as applications in aerodynamic, chemical, and physics experiments. Topics considered include a cryogenic shock tube for studying liquid helium fluid mechanics, studies of shock focusing and nonlinear resonance in shock tubes, applications in gas laser studies, very-low and very-high temperature chemical kinetic measurements, shock tube studies of ionization and recombination phenomena, applications in bioacoustic research, shock-tube simulation studies of sonic booms, and plasma research. Individual items are announced in this issue.

Electron tubes for industrial applications

NASA Astrophysics Data System (ADS)

Gellert, Bernd

1994-05-01

This report reviews research and development efforts within the last years for vacuum electron tubes, in particular power grid tubes for industrial applications. Physical and chemical effects are discussed that determine the performance of todays devices. Due to the progress made in the fundamental understanding of materials and newly developed processes the reliability and reproducibility of power grid tubes could be improved considerably. Modern computer controlled manufacturing methods ensure a high reproducibility of production and continuous quality certification according to ISO 9001 guarantees future high quality standards. Some typical applications of these tubes are given as an example.

The effect of cold application on pain due to chest tube removal.

PubMed

Ertuğ, Nurcan; Ulker, Saadet

2012-03-01

The aim of the research is to determine the effect of cold application on the pain owing to chest tube removal for patients with single pleural chest tube. Removal of chest tubes causes patients to feel pain and interventions used for reducing the pain owing to the removal of chest tubes are not sufficient. Controlled clinical trial with repeated measures. This study was conducted with 140 patients, of whom 70 patients were in the experimental group and 70 patients were in the control group, in a thoracic hospital in Turkey. Data were collected using a data collection form consisting of patients' demographic and health history and Visual Analogue Scale. Cold was applied to patients in the experimental group prior to chest tube removal. In the experimental group, skin temperature and pain intensity was measured for each patient at four time points. In the control group, pain intensity was evaluated for each patient at three time points. Data were evaluated using Chi-square and Repeated Measurements two-way anova tests. The Visual Analogue Scale score was measured immediately after the chest tube removal in the experimental group was 3·85, compared with 5·60 in the control group. There were significant differences on pain with cold application between the two groups prior and after the intervention. Age, gender, the number of days the chest tube was inserted and the chest tube insertion indication had no effect on the pain owing to chest tube removal. Cold application is effective in reducing the pain owing to chest tube removal. Cold application was recommended prior to chest tube removal to reduce the pain owing to removal of chest tube. © 2011 Blackwell Publishing Ltd.

21 CFR 524.1140 - Imidacloprid and ivermectin.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Imidacloprid and ivermectin. (a) Specifications. The product is available in unit applicator tubes containing 0.4, 1.0, 2.5, or 4.0 milliliters (mL). Each mL of solution contains 100 milligrams (mg) imidacloprid....1140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...

21 CFR 524.1140 - Imidacloprid and ivermectin.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Imidacloprid and ivermectin. (a) Specifications. The product is available in unit applicator tubes containing 0.4, 1.0, 2.5, or 4.0 milliliters (mL). Each mL of solution contains 100 milligrams (mg) imidacloprid....1140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...

Raster graphic helmet-mounted display study

NASA Technical Reports Server (NTRS)

Beamon, William S.; Moran, Susanna I.

1990-01-01

A design of a helmet mounted display system is presented, including a design specification and development plan for the selected design approach. The requirements for the helmet mounted display system and a survey of applicable technologies are presented. Three helmet display concepts are then described which utilize lasers, liquid crystal display's (LCD's), and subminiature cathode ray tubes (CRT's), respectively. The laser approach is further developed in a design specification and a development plan.

Impact of tubing material on the failure of product-specific bubble points of sterilizing-grade filters.

PubMed

Meyer, Brian K; Vargas, Diego

2006-01-01

The following study was conducted to determine the effect of different preservatives commonly used in the biopharmaceutical industry on the product-specific bubble point of sterilizing-grade filters when used to filter product processed with different types of tubing. The preservatives tested were 0.25% phenol, m-cresol, and benzyl alcohol. The tubing tested was Sani-Pure (platinum-cured silicone tubing), Versilic (peroxide-cured silicone tubing), C-Flex, Pharmed, and Cole-Parmer (BioPharm silicone tubing). The product-specific bubble point values of sterilizing grade filters were measured after the recirculation of product through the filter and tubing of different types of materials for a total contact time of 15 h. When silicone tubing was used, the post-recirculation product-specific bubble point was suppressed on average 13 psig when compared to the pre- recirculation product-specific bubble point. Suppression was also observed with C-Flex, but to a much lesser extent than with silicone tubing. Suppression was not observed with Pharmed or BioPharm tubing. Alcohol extractions performed on the filters that experienced suppressed bubble points followed by Fourier transform infrared spectroscopy analysis indicated the filters contained poly(dimethylsiloxane). Direct addition of poly(dimethlysiloxane) to solutions filtered through sterilizing-grade filters suppressed the filter bubble points when tested for integrity. Silicone oils most likely reduced the surface tension of the pores in the membrane, resulting in the ability of air (or nitrogen) to pass more freely through the membrane, causing suppressed bubble point test values. The results of these studies indicate that product-specific bubble point of a filter determined with only product may not reflect the true bubble point for preservative-containing products that are recirculated or contacted with certain tubing for 15 h or greater. In addition, tubing material placed in contact with products containing preservatives should be evaluated for impact to the product-specific bubble point when being utilized with sterilizing-grade filters.

Multiple tube premixing device

DOEpatents

Uhm, Jong Ho; Naidu, Balachandar; Ziminksy, Willy Steve; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin; Stevenson, Christian; Felling, David

2013-08-13

The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.

Multiple tube premixing device

DOEpatents

Uhm, Jong Ho; Varatharajan, Balachandar; Ziminsky, Willy Steve; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin; Stevenson, Christian; Felling, David

2012-12-11

The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.

49 CFR 179.500-18 - Inspection and reports.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500... forging or seamless tube accepted by him for use in making tanks, and shall verify proper application of heat number to such material by occasional inspections at steel manufacturer's plant. (3) Inspector...

49 CFR 179.500-18 - Inspection and reports.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500... forging or seamless tube accepted by him for use in making tanks, and shall verify proper application of heat number to such material by occasional inspections at steel manufacturer's plant. (3) Inspector...

49 CFR 179.500-18 - Inspection and reports.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500... forging or seamless tube accepted by him for use in making tanks, and shall verify proper application of heat number to such material by occasional inspections at steel manufacturer's plant. (3) Inspector...

49 CFR 179.500-18 - Inspection and reports.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500... forging or seamless tube accepted by him for use in making tanks, and shall verify proper application of heat number to such material by occasional inspections at steel manufacturer's plant. (3) Inspector...

Dose Estimating Application Software Modification: Additional Function of a Size-Specific Effective Dose Calculator and Auto Exposure Control.

PubMed

Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Suzuki, Shouichi; Matsunaga, Yuta; Haba, Tomonobu; Kawaguchi, Ai; Daioku, Tomihiko; Toyama, Hiroshi; Kato, Ryoichi

2017-05-01

Adequate dose management during computed tomography is important. In the present study, the dosimetric application software ImPACT was added to a functional calculator of the size-specific dose estimate and was part of the scan settings for the auto exposure control (AEC) technique. This study aimed to assess the practicality and accuracy of the modified ImPACT software for dose estimation. We compared the conversion factors identified by the software with the values reported by the American Association of Physicists in Medicine Task Group 204, and we noted similar results. Moreover, doses were calculated with the AEC technique and a fixed-tube current of 200 mA for the chest-pelvis region. The modified ImPACT software could estimate each organ dose, which was based on the modulated tube current. The ability to perform beneficial modifications indicates the flexibility of the ImPACT software. The ImPACT software can be further modified for estimation of other doses. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A personalized food allergen testing platform on a cellphone

PubMed Central

Coskun, Ahmet F.; Wong, Justin; Khodadadi, Delaram; Nagi, Richie; Tey, Andrew; Ozcan, Aydogan

2013-01-01

We demonstrate a personalized food allergen testing platform, termed iTube, running on a cellphone that images and automatically analyses colorimetric assays performed in test tubes toward sensitive and specific detection of allergens in food samples. This cost-effective and compact iTube attachment, weighing approximately 40 grams, is mechanically installed on the existing camera unit of a cellphone where the test and control tubes are inserted from the side and are vertically illuminated by two separate light-emitting-diodes. The illumination light is absorbed by the allergen assay that is activated within the tubes, causing an intensity change in the acquired images by the cellphone camera. These transmission images of the sample and control tubes are digitally processed within1 sec using a smart application running on the same cellphone for detection and quantification of allergen contamination in food products. We evaluated the performance of this cellphone based iTube platform using different types of commercially available cookies, where the existence of peanuts was accurately quantified after a sample preparation and incubation time of ~20 min per test. This automated and cost-effective personalized food allergen testing tool running on cellphones can also permit uploading of test results to secure servers to create personal and/or public spatio-temporal allergen maps, which can be useful for public health in various settings. PMID:23254910

Air Liquide's pulse tube cryocooler systems for space applications

NASA Astrophysics Data System (ADS)

Trollier, T.; Tanchon, J.; Rey, J. C.; Ravex, A.; Buquet, J.

2009-05-01

Thanks to important development efforts completed internally and with the European Space Agency (ESA) funding, Air Liquide Advanced Technology Division (AL/DTA) is now in position to propose two Pulse Tube cooler systems in the 40-80K temperature range for coming Earth Observation missions such as Meteosat Third Generation (MTG), SIFTI, etc... The Miniature Pulse Tube Cooler (MPTC) is lifting up to 2.47W@80K with 50W maximal compressor input power and 10°C rejection temperature. The weight is 2.8 kg. The Large Pulse Tube Cooler (LPTC) is providing 2.3W@50K for 160W input power and 10°C rejection temperature. This product is weighing 5.1 kg. The two pulse tube coolers thermo-mechanical units are qualified against environmental constraints as per ESA ECSS-E-30. They are both using dual opposed pistons flexure bearing compressor with moving magnet linear motors in order to ensure very high lifetime. The associated Cooler Drive Electronics is also an important aspect specifically regarding the active control of the cooler thermo-mechanical unit during the launch phase and the active reduction of the vibrations induced by the compressor (partly supported by the French Agency CNES). This paper details the presentation of the two Pulse Tube Coolers together with the Cooler Drive Electronics aspects.

Measurements and computations of mass flow and momentum flux through short tubes in rarefied gases

NASA Astrophysics Data System (ADS)

Lilly, T. C.; Gimelshein, S. F.; Ketsdever, A. D.; Markelov, G. N.

2006-09-01

Gas flows through orifices and short tubes have been extensively studied from the 1960s through the 1980s for both fundamental and practical reasons. These flows are a basic and often important element of various modern gas driven instruments. Recent advances in micro- and nanoscale technologies have paved the way for a generation of miniaturized devices in various application areas, from clinical analyses to biochemical detection to aerospace propulsion. The latter is the main area of interest of this study, where rarefied gas flow into a vacuum through short tubes with thickness-to-diameter ratios varying from 0.015 to 1.2 is investigated both experimentally and numerically with kinetic and continuum approaches. Helium and nitrogen gases are used in the range of Reynolds numbers from 0.02 to 770 (based on the tube diameter), corresponding to Knudsen numbers from 40 down to about 0.001. Propulsion properties of relatively thin and thick tubes are examined. Good agreement between experimental and numerical results is observed for mass flow rate and momentum flux, the latter being corrected for the experimental facility background pressure. For thick-to-thin tube ratios of mass flow and momentum flux versus pressure, a minimum is observed at a Knudsen number of about 0.5. A short tube propulsion efficiency is shown to be much higher than that of a thin orifice. The effect of surface specularity on a thicker tube specific impulse was found to be relatively small.

Single tube genotyping of sickle cell anaemia using PCR-based SNP analysis

PubMed Central

Waterfall, Christy M.; Cobb, Benjamin D.

2001-01-01

Allele-specific amplification (ASA) is a generally applicable technique for the detection of known single nucleotide polymorphisms (SNPs), deletions, insertions and other sequence variations. Conventionally, two reactions are required to determine the zygosity of DNA in a two-allele system, along with significant upstream optimisation to define the specific test conditions. Here, we combine single tube bi-directional ASA with a ‘matrix-based’ optimisation strategy, speeding up the whole process in a reduced reaction set. We use sickle cell anaemia as our model SNP system, a genetic disease that is currently screened using ASA methods. Discriminatory conditions were rapidly optimised enabling the unambiguous identification of DNA from homozygous sickle cell patients (HbS/S), heterozygous carriers (HbA/S) or normal DNA in a single tube. Simple downstream mathematical analyses based on product yield across the optimisation set allow an insight into the important aspects of priming competition and component interactions in this competitive PCR. This strategy can be applied to any polymorphism, defining specific conditions using a multifactorial approach. The inherent simplicity and low cost of this PCR-based method validates bi-directional ASA as an effective tool in future clinical screening and pharmacogenomic research where more expensive fluorescence-based approaches may not be desirable. PMID:11726702

Single tube genotyping of sickle cell anaemia using PCR-based SNP analysis.

PubMed

Waterfall, C M; Cobb, B D

2001-12-01

Allele-specific amplification (ASA) is a generally applicable technique for the detection of known single nucleotide polymorphisms (SNPs), deletions, insertions and other sequence variations. Conventionally, two reactions are required to determine the zygosity of DNA in a two-allele system, along with significant upstream optimisation to define the specific test conditions. Here, we combine single tube bi-directional ASA with a 'matrix-based' optimisation strategy, speeding up the whole process in a reduced reaction set. We use sickle cell anaemia as our model SNP system, a genetic disease that is currently screened using ASA methods. Discriminatory conditions were rapidly optimised enabling the unambiguous identification of DNA from homozygous sickle cell patients (HbS/S), heterozygous carriers (HbA/S) or normal DNA in a single tube. Simple downstream mathematical analyses based on product yield across the optimisation set allow an insight into the important aspects of priming competition and component interactions in this competitive PCR. This strategy can be applied to any polymorphism, defining specific conditions using a multifactorial approach. The inherent simplicity and low cost of this PCR-based method validates bi-directional ASA as an effective tool in future clinical screening and pharmacogenomic research where more expensive fluorescence-based approaches may not be desirable.

Protein separation through preliminary experiments concerning pH and salt concentration by tube radial distribution chromatography based on phase separation multiphase flow using a polytetrafluoroethylene capillary tube.

PubMed

Kan, Hyo; Tsukagoshi, Kazuhiko

2017-07-01

Protein mixtures were separated using tube radial distribution chromatography (TRDC) in a polytetrafluoroethylene (PTFE) capillary (internal diameter=100µm) separation tube. Separation by TRDC is based on the annular flow in phase separation multiphase flow and features an open-tube capillary without the use of specific packing agents or application of high voltages. Preliminary experiments were conducted to examine the effects of pH and salt concentration on the phase diagram of the ternary mixed solvent solution of water-acetonitrile-ethyl acetate (8:2:1 volume ratio) and on the TRDC system using the ternary mixed solvent solution. A model protein mixture containing peroxidase, lysozyme, and bovine serum albumin was analyzed via TRDC with the ternary mixed solvent solution at various pH values, i.e., buffer-acetonitrile-ethyl acetate (8:2:1 volume ratio). Protein was separated on the chromatograms by the TRDC system, where the elution order was determined by the relation between the isoelectric points of protein and the pH values of the solvent solution. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 426.100 - Applicability; description of the glass tubing (Danner) manufacturing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... glass tubing (Danner) manufacturing subcategory. 426.100 Section 426.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Glass Tubing (Danner) Manufacturing Subcategory § 426.100 Applicability; description of the glass...

40 CFR 426.100 - Applicability; description of the glass tubing (Danner) manufacturing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... glass tubing (Danner) manufacturing subcategory. 426.100 Section 426.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Glass Tubing (Danner) Manufacturing Subcategory § 426.100 Applicability; description of the glass...

Chemical vapor deposition of Mo tubes for fuel cladding applications

DOE PAGES

Beaux, Miles F.; Vodnik, Douglas R.; Peterson, Reuben J.; ...

2018-01-31

In this study, chemical vapor deposition (CVD) techniques have been evaluated for fabrication of free-standing 0.25 mm thick molybdenum tubes with the end goal of nuclear fuel cladding applications. In order to produce tubes with the wall thickness and microstructures desirable for this application, long deposition durations on the order of 50 h with slow deposition rates were employed. A standard CVD method, involving molybdenum pentachloride reduction by hydrogen, as well as a fluidized-bed CVD (FBCVD) method was applied towards these objectives. Characterization of the tubes produced in this manner revealed regions of material with fine grain microstructure and wallmore » thickness suitable for fuel cladding applications, but lacking necessary uniformity across the length of the tubes. Finally, a path forward for the production of freestanding molybdenum tubes that possess the desired properties across their entire length has been identified and can be accomplished by future optimization of the deposition system.« less

Chemical vapor deposition of Mo tubes for fuel cladding applications

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

Beaux, Miles F.; Vodnik, Douglas R.; Peterson, Reuben J.

In this study, chemical vapor deposition (CVD) techniques have been evaluated for fabrication of free-standing 0.25 mm thick molybdenum tubes with the end goal of nuclear fuel cladding applications. In order to produce tubes with the wall thickness and microstructures desirable for this application, long deposition durations on the order of 50 h with slow deposition rates were employed. A standard CVD method, involving molybdenum pentachloride reduction by hydrogen, as well as a fluidized-bed CVD (FBCVD) method was applied towards these objectives. Characterization of the tubes produced in this manner revealed regions of material with fine grain microstructure and wallmore » thickness suitable for fuel cladding applications, but lacking necessary uniformity across the length of the tubes. Finally, a path forward for the production of freestanding molybdenum tubes that possess the desired properties across their entire length has been identified and can be accomplished by future optimization of the deposition system.« less

Design of 3-D Printed Concentric Tube Robots.

PubMed

Morimoto, Tania K; Okamura, Allison M

2016-12-01

Concentric tube surgical robots are minimally invasive devices with the advantages of snake-like reconfigurability, long and thin form factor, and placement of actuation outside the patient's body. These robots can also be designed and manufactured to acquire targets in specific patients for treating specific diseases in a manner that minimizes invasiveness. We propose that concentric tube robots can be manufactured using 3-D printing technology on a patient- and procedure-specific basis. In this paper, we define the design requirements and manufacturing constraints for 3-D printed concentric tube robots and experimentally demonstrate the capabilities of these robots. While numerous 3-D printing technologies and materials can be used to create such robots, one successful example uses selective laser sintering to make an outer tube with a polyether block amide and uses stereolithography to make an inner tube with a polypropylene-like material. This enables a tube pair with precurvatures of 0.0775 and 0.0455 mm -1 , which can withstand strains of 20% and 5.5% for the outer and inner tubes, respectively.

Defect specific maintenance of SG tubes -- How safe is it?

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

Cizelj, L.; Mavko, B.; Dvorsek, T.

1997-02-01

The efficiency of the defect specific plugging criterion for outside diameter stress corrosion cracking at tube support plates is assessed. The efficiency is defined by three parameters: (1) number of plugged tubes, (2) probability of steam generator tube rupture and (3) predicted accidental leak rate through the defects. A probabilistic model is proposed to quantify the probability of tube rupture, while procedures available in literature were used to define the accidental leak rates. The defect specific plugging criterion was then compared to the performance of traditional (45%) plugging criterion using realistic data from Krsko nuclear power plant. Advantages of themore » defect specific approach over the traditional one are clearly shown. Some hints on the optimization of safe life of steam generator are also given.« less

Testing of Military Towbars

DTIC Science & Technology

2016-09-28

pin diameters, lunette diameter, clevis end details, cross section, and overall tube length and straightness. b. Weld failures, voids, cracks...etc., should be considered failures if they are identified visually or using a nondestructive weld inspection test method, per the applicable American... Welding Society standard for the specific material being inspected. c. Broken or cracked components, or catastrophic damage should be considered

Low Voltage Electron Beam Processing Final Report CRADA No. TC-645-93-A

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

Chen, H.; Wakalopulos, G.

This CRADA project was established to develop a small, inexpensive sealed-tube electron beam processing system having immediate applications in industrial, high speed manufacturing processes, and in the Department of Energy (DOE) waste treatment/cleanup operations. The technical work involved the development and demonstration of a compact, sealed, 50-75 kilovolt (kV) EB generator prototype, including controls and power supply. The specific goals of this project were to develop a low cost vacuum tube capable of shooting an electron beam several inches into the air, and to demonstrate that wide area materials processing is feasible by stacking the tubes to produce continuous beams.more » During the project, we successfully demonstrated the producibility of a low cost electron beam system and several material processing operations of interest to US industry, DOE and, since September 11, 2001, the Homeland Security.« less

Utilization of geotextile tube for sandy and muddy coastal management: a review.

PubMed

Lee, Siew Cheng; Hashim, Roslan; Motamedi, Shervin; Song, Ki-Il

2014-01-01

Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper.

Performance improvements of the BNC tubes from unique double-silicone-tube bioreactors by introducing chitosan and heparin for application as small-diameter artificial blood vessels.

PubMed

Li, Xue; Tang, Jingyu; Bao, Luhan; Chen, Lin; Hong, Feng F

2017-12-15

In order to improve property of bacterial nano-cellulose (BNC) to achieve the requirements of clinical application as small caliber vascular grafts, chitosan (CH) was deposited into the fibril network of the BNC tubes fabricated in unique Double-Silicone-Tube bioreactors. Heparin (Hep) was then chemically grafted into the BNC-based tubes using EDC/NHS crosslinking to improve performance of anticoagulation and endothelialization. Physicochemical and mechanical property, blood compatibility, and cytocompatibility were compared before and after compositing. The results indicated that strength at break was increased but burst pressure decreased slightly after compositing. Performance of the BNC tubes was improved remarkably after introducing chitosan and heparin. The EDC/NHS crosslinking catalyzed both amide bonds and ester bonds formation in the BNC/CH-Hep composites. Three-dimensional surface structure and roughness were firstly obtained and discussed in relation to the hemocompatibility of BNC-based tubes. This work demonstrates the heparinized BNC-based tubes have great potential in application as small-diameter vascular prosthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Utilization of Geotextile Tube for Sandy and Muddy Coastal Management: A Review

PubMed Central

Lee, Siew Cheng; Hashim, Roslan; Motamedi, Shervin; Song, Ki-Il

2014-01-01

Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper. PMID:24955408

Argon hollow cathode. M.S. Thesis; [propellants for ion bombardment thrusters

NASA Technical Reports Server (NTRS)

Rehn, L. A.

1976-01-01

An interest in alternate propellants for ion-bombardment thrusters, together with ground applications of this technology, has prompted consideration of argon. Several variations of conventional hollow cathode designs were tried, but the bulk of the testing used a hollow tube with an internal tungsten emitter and an orifice at one end. The optimum cathode tube diameter was found to be in the range of 1.0-2.5 cm, somewhat larger than those used for cesium and mercury. Optimum orifice diameter depended on operating conditions, and varied from 0.5 to 5 mm. Biasing the internal emitter negative relative to the cathode chamber reduced the external coupling voltage and should therefore improve orifice lifetime. The expected effect of this bias on emitter lifetime was less clear. Lifetime tests were not conducted as part of this investigation, but several designs show promise of long lifetime in specific applications.

Method for shaping polyethylene tubing

NASA Technical Reports Server (NTRS)

Kramer, R. C.

1981-01-01

Method forms polyethylene plastic tubing into configurations previously only possible with metal tubing. By using polyethylene in place of copper or stain less steel tubing inlow pressure systems, fabrication costs are significantly reduced. Polyethylene tubing can be used whenever low pressure tubing is needed in oil operations, aircraft and space applications, powerplants, and testing laboratories.

Liquid-Nitrogen Test for Blocked Tubes

NASA Technical Reports Server (NTRS)

Wagner, W. R.

1984-01-01

Nondestructive test identifies obstructed tube in array of parallel tubes. Trickle of liquid nitrogen allowed to flow through tube array until array accumulates substantial formation of frost from moisture in air. Flow stopped and warm air introduced into inlet manifold to heat tubes in array. Tubes still frosted after others defrosted identified as obstructed tubes. Applications include inspection of flow systems having parallel legs.

Laboratory Applications of the Vortex Tube.

ERIC Educational Resources Information Center

Bruno, Thomas J.

1987-01-01

Discussed are a brief explanation of the function of the vortex tube and some applications for the chemistry laboratory. It is a useful and inexpensive solution to many small-scale laboratory heating and cooling applications. (RH)

Germ tube-specific antigens of Candida albicans cell walls

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

Sundstrom, P.R.

1986-01-01

Studies were performed to characterize the surface differences between blastospores and germ tubes of the pathogenic, dimorphic yeast, Candida albicans, and to identify components of yeast cells responsible for these differences. Investigation of surfaces differences of the two growth forms was facilitated by the production of rabbit antiserum prepared against Formalin-treated yeast possessing germ tubes. To prepare antiserum specific for germ tubes, this serum was adsorbed with stationary phase blastospores. Whereas the unadsorbed antiserum reacted with both blastospore and germ tube forms by immunofluorescence and Enzyme-Linked Immunosorbent Assay, the adsorbed antiserum did not react with blastospores but detected germ tube-specificmore » antigens in hyphal forms. The differences between blastospores and germ tubes of Candida albicans, were further studied by comparing enzymatic digests of cell walls of both growth forms in radiolabeled organisms. Organisms were labeled either on the surface with /sup 125/I, or metabolically with (/sup 35/S) methionine or (/sup 3/H) mannose. Three-surface-located components (as shown by antibody adsorption and elution experiments) were precipitated from Zymolase digests. All three components were mannoproteins as shown by their ability to bind Concanavalin A, and to be labeled in protein labeling procedures, and two of these (200,000 and 155,000 molecular weight) were germ tube specific, as shown by their ability to be precipitated by germ tube-specific antiserum. Monoclonal antibodies were prepared to C. albicans, using blastospores bearing germ tubes as immunogen.« less

RP-1 Thermal Stability and Copper Based Materials Compatibility Study

NASA Technical Reports Server (NTRS)

Stiegemeier, B. R.; Meyer, M. L.; Driscoll, E.

2005-01-01

A series of electrically heated tube tests was performed at the NASA Glenn Research Center s Heated Tube Facility to investigate the effect that sulfur content, test duration, and tube material play in the overall thermal stability and materials compatibility characteristics of RP-1. Scanning-electron microscopic (SEM) analysis in conjunction with energy dispersive spectroscopy (EDS) were used to characterize the condition of the tube inner wall surface and any carbon deposition or corrosion formed during these runs. Results of the parametric study indicate that tests with standard RP-1 (total sulfur -23 ppm) and pure copper tubing are characterized by a depostion/deposit shedding process producing local wall temperature swings as high as 500 F. The effect of this shedding is to keep total carbon deposition levels relatively constant for run times from 20 minutes up to 5 hours, though increasing tube pressure drops were observed in all runs. Reduction in the total sulfur content of the fuel from 23 ppm to less than 0.1 ppm resulted in the elimination of deposit shedding, local wall temperature variation, and the tube pressure drop increases that were observed in standard sulfur level RP-1 tests. The copper alloy GRCop-84, a copper alloy developed specifically for high heat flux applications, was found to exhibit higher carbon deposition levels compared to identical tests performed in pure copper tubes. Results of the study are consistent with previously published heated tube data which indicates that small changes in fuel total sulfur content can lead to significant differences in the thermal stability of kerosene type fuels and their compatibility with copper based materials. In conjunction with the existing thermal stability database, these findings give insight into the feasibility of cooling a long life, high performance, high-pressure liquid rocket combustor and nozzle with RP-1.

Design of 3-D Printed Concentric Tube Robots

PubMed Central

Morimoto, Tania K.; Okamura, Allison M.

2017-01-01

Concentric tube surgical robots are minimally invasive devices with the advantages of snake-like reconfigurability, long and thin form factor, and placement of actuation outside the patient’s body. These robots can also be designed and manufactured to acquire targets in specific patients for treating specific diseases in a manner that minimizes invasiveness. We propose that concentric tube robots can be manufactured using 3-D printing technology on a patient- and procedure-specific basis. In this paper, we define the design requirements and manufacturing constraints for 3-D printed concentric tube robots and experimentally demonstrate the capabilities of these robots. While numerous 3-D printing technologies and materials can be used to create such robots, one successful example uses selective laser sintering to make an outer tube with a polyether block amide and uses stereolithography to make an inner tube with a polypropylene-like material. This enables a tube pair with precurvatures of 0.0775 and 0.0455 mm−1, which can withstand strains of 20% and 5.5% for the outer and inner tubes, respectively. PMID:28713227

Resonant Circuits and Introduction to Vacuum Tubes, Industrial Electronics 2: 9325.03. Course Outline.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

The 135 clock-hour course for the 11th year consists of outlines for blocks of instruction on series resonant circuits, parallel resonant circuits, transformer theory and application, vacuum tube fundamentals, diode vacuum tubes, triode tube construction and parameters, vacuum tube tetrodes and pentodes, beam-power and multisection tubes, and…

Rolling-Tooth Core Breakoff and Retention Mechanism

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Bickler, Donald B.; Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi; Hudson, Nicolas H.

2011-01-01

Sampling cores requires the controlled breakoff of the core at a known location with respect to the drill end. An additional problem is designing a mechanism that can be implemented at a small scale that is robust and versatile enough to be used for a variety of core samples. This design consists of a set of tubes (a drill tube and an inner tube) and a rolling element (rolling tooth). An additional tube can be used as a sample tube. The drill tube and the inner tube have longitudinal holes with the axes offset from the axis of each tube. The two eccentricities are equal. The inner tube fits inside the drill tube, and the sample tube fits inside the inner tube. While drilling, the two tubes are positioned relative to each other such that the sample tube is aligned with the drill tube axis and core. The drill tube includes teeth and flutes for cuttings removal. The inner tube includes, at the base, the rolling element implemented as a wheel on a shaft in an eccentric slot. An additional slot in the inner tube and a pin in the drill tube limit the relative motion of the two tubes. While drilling, the drill assembly rotates relative to the core and forces the rolling tooth to stay hidden in the slot along the inner tube wall. When the drilling depth has been reached, the drill bit assembly is rotated in the opposite direction, and the rolling tooth is engaged and penetrates into the core. Depending on the strength of the created core, the rolling tooth can score, lock the inner tube relative to the core, start the eccentric motion of the inner tube, and break the core. The tooth and the relative position of the two tubes can act as a core catcher or core-retention mechanism as well. The design was made to fit the core and hole parameters produced by an existing bit; the parts were fabricated and a series of demonstration tests were performed. This invention is potentially applicable to sample return and in situ missions to planets such as Mars and Venus, to moons such as Titan and Europa, and to comets. It is also applicable to terrestrial applications like forensic sampling and geological sampling in the field.

Surgeon Design Interface for Patient-Specific Concentric Tube Robots

PubMed Central

Morimoto, Tania K.; Greer, Joseph D.; Hsieh, Michael H.; Okamura, Allison M.

2017-01-01

Concentric tube robots have potential for use in a wide variety of surgical procedures due to their small size, dexterity, and ability to move in highly curved paths. Unlike most existing clinical robots, the design of these robots can be developed and manufactured on a patient- and procedure-specific basis. The design of concentric tube robots typically requires significant computation and optimization, and it remains unclear how the surgeon should be involved. We propose to use a virtual reality-based design environment for surgeons to easily and intuitively visualize and design a set of concentric tube robots for a specific patient and procedure. In this paper, we describe a novel patient-specific design process in the context of the virtual reality interface. We also show a resulting concentric tube robot design, created by a pediatric urologist to access a kidney stone in a pediatric patient. PMID:28656124

Surgeon Design Interface for Patient-Specific Concentric Tube Robots.

PubMed

Morimoto, Tania K; Greer, Joseph D; Hsieh, Michael H; Okamura, Allison M

2016-06-01

Concentric tube robots have potential for use in a wide variety of surgical procedures due to their small size, dexterity, and ability to move in highly curved paths. Unlike most existing clinical robots, the design of these robots can be developed and manufactured on a patient- and procedure-specific basis. The design of concentric tube robots typically requires significant computation and optimization, and it remains unclear how the surgeon should be involved. We propose to use a virtual reality-based design environment for surgeons to easily and intuitively visualize and design a set of concentric tube robots for a specific patient and procedure. In this paper, we describe a novel patient-specific design process in the context of the virtual reality interface. We also show a resulting concentric tube robot design, created by a pediatric urologist to access a kidney stone in a pediatric patient.

An Evaluation of Jet Impingement Heat Transfer Correlations for Piccolo Tube Application

NASA Technical Reports Server (NTRS)

Bond, Thomas (Technical Monitor); Wright, William B.

2004-01-01

Impinging jets have been used for a wide variety of applications where high rates of heat transfer are desired. This report will present a review of heat transfer correlations that have been published. The correlations were then added to the LEWICE software to evaluate the applicability of these correlations to a piccolo tube anti-icing system. The results of this analysis were then compared quantitatively to test results on a representative piccolo tube system.

Medical X-ray sources now and for the future

NASA Astrophysics Data System (ADS)

Behling, Rolf

2017-11-01

This paper focuses on the use of X-rays in their largest field of application: medical diagnostic imaging and image-guided therapy. For this purpose, vacuum electronics in the form of X-ray tubes as the source of bremsstrahlung (braking radiation) have been the number one choice for X-ray production in the range of photon energies between about 16 keV for mammography and 150 keV for general radiography. Soft tissue on one end and bony structures on the other are sufficiently transparent and the contrast delivered by difference of absorption is sufficiently high for this spectral range. The dominance of X-ray tubes holds even more than 120 years after Conrad Roentgen's discovery of the bremsstrahlung mechanism. What are the specifics of current X-ray tubes and their medical diagnostic applications? How may the next available technology at or beyond the horizon look like? Can we hope for substantial game changers? Will flat panel sources, less expensive X-ray "LED's", compact X-ray Lasers, compact synchrotrons or equivalent X-ray sources appear in medical diagnostic imaging soon? After discussing the various modalities of imaging systems and their sources of radiation, this overview will briefly touch on the physics of bremsstrahlung generation, key characteristics of X-ray tubes, and material boundary conditions, which restrict performance. It will discuss the deficits of the bremsstrahlung technology and try to sketch future alternatives and their prospects of implementation in medical diagnostics.

eFAST for Pneumothorax: Real-Life Application in an Urban Level 1 Center by Trauma Team Members.

PubMed

Maximus, Steven; Figueroa, Cesar; Whealon, Matthew; Pham, Jacqueline; Kuncir, Eric; Barrios, Cristobal

2018-02-01

The focused assessment with sonography for trauma (FAST) examination has become the standard of care for rapid evaluation of trauma patients. Extended FAST (eFAST) is the use of ultrasonography for the detection of pneumothorax (PTX). The exact sensitivity and specificity of eFAST detecting traumatic PTX during practical "real-life" application is yet to be investigated. This is a retrospective review of all trauma patients with a diagnosis of PTX, who were treated at a large level 1 urban trauma center from March 2013 through July 2014. Charts were reviewed for results of imaging, which included eFAST, chest X-ray, and CT scan. The requirement of tube thoracostomy and mechanism of injury were also analyzed. A total of 369 patients with a diagnosis of PTX were identified. A total of 69 patients were excluded, as eFAST was either not performed or not documented, leaving 300 patients identified with PTX. A total of 113 patients had clinically significant PTX (37.6%), requiring immediate tube thoracostomy placement. eFAST yielded a positive diagnosis of PTX in 19 patients (16.8%), and all were clinically significant, requiring tube thoracostomy. Chest X-ray detected clinically significant PTX in 105 patients (92.9%). The literature on the utility of eFAST for PTX in trauma is variable. Our data show that although specific for clinically significant traumatic PTX, it has poor sensitivity when performed by clinicians with variable levels of ultrasound training. We conclude that CT is still the gold standard in detecting PTX, and clinicians performing eFAST should have adequate training.

Characterization of Friction Stir Welded Tubes by Means of Tube Bulge Test

NASA Astrophysics Data System (ADS)

D'Urso, G.; Longo, M.; Giardini, C.

2011-05-01

Mechanical properties of friction stir welded joints are generally evaluated by means of conventional tensile test. This testing method might provide insufficient information because maximum strain obtained in tensile test before necking is small; moreover, the application of tensile test is limited when the joint path is not linear or even when the welds are executed on curved surfaces. Therefore, in some cases, it would be preferable to obtain the joints properties from other testing methods. Tube bulge test can be a valid solution for testing circumferential or longitudinal welds executed on tubular workpieces. The present work investigates the mechanical properties and the formability of friction stir welded tubes by means of tube bulge tests. The experimental campaign was performed on tubular specimens having a thickness of 3 mm and an external diameter of 40 mm, obtained starting from two semi-tubes longitudinally friction stir welded. The first step, regarding the fabrication of tubes, was performed combining a conventional forming process and friction stir welding. Sheets in Al-Mg-Si-Cu alloy AA6060 T6 were adopted for this purpose. Plates having a dimension of 225×60 mm were bent (with a bending axis parallel to the main dimension) in order to obtain semi-tubes. A particular care was devoted to the fabrication of forming devices (punch and die) in order to minimize the springback effects. Semi-tubes were then friction stir welded by means of a CNC machine tool. Some preliminary tests were carried out by varying the welding parameters, namely feed rate and rotational speed. A very simple tool having flat shoulder and cylindrical pin was used. The second step of the research was based on testing the welded tubes by means of tube bulge test. A specific equipment having axial actuators with a conical shape was adopted for this study. Some analyses were carried out on the tubes bulged up to a certain pressure level. In particular, the burst pressure and the wall thickness were measured for each tested tube.

Inertance Tube Modeling and the Effects of Temperature

DTIC Science & Technology

2010-01-01

fluid dynamics. In one application in multistage cryocoolers , the performance of inertance tubes at the cryogenic temperatures is of interest. One... cryocoolers , the performance of inertance tubes at the cryogenic temperatures is of interest. One purpose of this paper is to understand how...acoustic power. KEYWORDS: Inertance tube, cryocoolers , pulse tube refrigerators, oscillating flow, computational fluid dynamics INTRODUCTION Pulse

Air-liquid solar collector for solar heating, combined heating and cooling, and hot water subsystems

NASA Technical Reports Server (NTRS)

1978-01-01

A collection of quarterly reports consisting of the installation and layout design of the air collector system for commercial applications, completion of the preliminary design review, detailed design efforts, and preparation of the verification test plan are given. Performance specifications and performance testing of a prototype model of a two manifold, 144 tube air collector array is presented.

[Drug application in patients with artificial nutritional support via tubes].

PubMed

Pfaff, A

2006-06-01

There has been an increasing number of patients with artificial nutritional support via tubes in the last few years. The inpatient setting as well as the outpatient setting is affected by this matter Physicians, nurses, pharmacists, and relatives have to deal with issues of drug application via tubes. In many cases a few drugs are to be administred via tube in addition to the artificial nutrition. The choice of the appropriate drug is of importance beyond other things to avoid intricacies and to ensure a safe and effective therapy.

30 CFR 7.21 - Purpose and effective date.

Code of Federal Regulations, 2013 CFR

2013-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7... brattice cloth and ventilation tubing. It is effective August 22, 1988. Applications for approval or...

30 CFR 7.21 - Purpose and effective date.

Code of Federal Regulations, 2014 CFR

2014-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7... brattice cloth and ventilation tubing. It is effective August 22, 1988. Applications for approval or...

30 CFR 7.21 - Purpose and effective date.

Code of Federal Regulations, 2012 CFR

2012-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7... brattice cloth and ventilation tubing. It is effective August 22, 1988. Applications for approval or...

30 CFR 7.21 - Purpose and effective date.

Code of Federal Regulations, 2010 CFR

2010-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7... brattice cloth and ventilation tubing. It is effective August 22, 1988. Applications for approval or...

30 CFR 7.21 - Purpose and effective date.

Code of Federal Regulations, 2011 CFR

2011-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7... brattice cloth and ventilation tubing. It is effective August 22, 1988. Applications for approval or...

76 FR 66763 - Models for Plant-Specific Adoption of Technical Specifications Task Force Traveler TSTF-510...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

... of Technical Specifications Task Force Traveler TSTF-510, Revision 2, ``Revision to Steam Generator..., Revision 2, ``Revision to Steam Generator [(SG)] Program Inspection Frequencies and Tube Sample Selection..., ``Steam Generator (SG) Program,'' Specification 5.6.7, ``Steam Generator Tube Inspection Report,'' and the...

Qualification of oil-based tracer particles for heated Ludwieg tubes

NASA Astrophysics Data System (ADS)

Casper, Marcus; Stephan, Sören; Scholz, Peter; Radespiel, Rolf

2014-06-01

The generation, insertion, pressurization and use of oil-based tracer particles is qualified for the application in heated flow facilities, typically hypersonic facilities such as Ludwieg tubes. The operative challenges are to ensure a sub-critical amount of seeding material in the heated part, to qualify the methods that are used to generate the seeding, pressurize it to storage tube pressure, as well as to test specific oil types. The mass of the seeding material is held below the lower explosion limit such that operation is safe. The basis for the tracers is qualified in off-situ particle size measurements. In the main part different methods and operational procedures are tested with respect to their ability to generate a suitable amount of seeding in the test section. For the best method the relaxation time of the tracers is qualified by the oblique shock wave test. The results show that the use of a special temperature resistant lubricant oil "Plantfluid" is feasible under the conditions of a Mach-6 Ludwieg tube with heated storage tube. The method gives high-quality tracers with high seeding densities. Although the experimental results of the oblique shock wave test differ from theoretical predictions of relaxation time, still the relaxation time of 3.2 μs under the more dense tunnel conditions with 18 bar storage tube pressure is low enough to allow the use of the seeding for meaningful particle image velocimetry studies.

Application of EAP materials toward a refreshable Braille display

NASA Astrophysics Data System (ADS)

Di Spigna, N.; Chakraborti, P.; Yang, P.; Ghosh, T.; Franzon, P.

2009-03-01

The development of a multiline, refreshable Braille display will assist with the full inclusion and integration of blind people into society. The use of both polyvinylidene fluoride (PVDF) film planar bending mode actuators and silicone dielectric elastomer cylindrical tube actuators have been investigated for their potential use in a Braille cell. A liftoff process that allows for aggressive scaling of miniature bimorph actuators has been developed using standard semiconductor lithography techniques. The PVDF bimorphs have been demonstrated to provide enough displacement to raise a Braille dot using biases less than 1000V and operating at 10Hz. In addition, silicone tube actuators have also been demonstrated to achieve the necessary displacement, though requiring higher voltages. The choice of electrodes and prestrain conditions aimed at maximizing axial strain in tube actuators are discussed. Characterization techniques measuring actuation displacement and blocking forces appropriate for standard Braille cell specifications are presented. Finally, the integration of these materials into novel cell designs and the fabrication of a prototype Braille cell are discussed.

NTF: Soldering Technology Development for Cryogenics

NASA Technical Reports Server (NTRS)

Hall, E. T., Jr.

1985-01-01

The advent of the National Transonic Facility (NTF) brought about a new application for an old joining method, soldering. Soldering for use at cryogenic temperatures requires that solders remain ductile and free from tin-pest (grey tin), have toughness to withstand aerodynamic loads associated with flight research, and maintain their surface finishes. Solders are used to attach 347 Stainless-Steel tubing in surface grooves of models. The solder must fill up the gap and metallurgically bound to the tubing and model. Cryogenic temperatures require that only specific materials for models can be used, including: Vasco Max 200 CVM, lescalloy A-286 Vac Arc, pH 13-8 Mo. Solders identified for testing at this time are: 50% Sn - 49.5% Pb - 0.5% Sb, 95% Sn - 5% Sb, 50% In 50% Pb, and 37.5% Sn - 37.5% Pb - 25% In. With these materials and solders, it is necessary to determine their solderability. After solderability is determined, tube/groove specimens are fabricated and stressed under cryogenic temperatures. Compatible solders are then used for acutual models.

Studies on Phase Shifting Mechanism in Pulse Tube Cryocooler

NASA Astrophysics Data System (ADS)

Padmanabhan; Gurudath, C. S.; Srikanth, Thota; Ambirajan, A.; Basavaraj, SA; Dinesh, Kumar; Venkatarathnam, G.

2017-02-01

Pulse Tube cryocoolers (PTC) are being used extensively in spacecraft for applications such as sensor cooling due to their simple construction and long life owing to a fully passive cold head. Efforts at ISRO to develop a PTC for space use have resulted in a unit with a cooling capacity of 1W at 80K with an input of 45watts. This paper presents the results of a study with this PTC on the phase shifting characteristics of an Inertance tube in conjunction with a reservoir. The aim was to obtain an optimum phase angle between the mass flow (ṁ) and dynamic pressure (\\tilde p) at the PT cold end that results in the largest possible heat lift from this unit. Theoretical model was developed using Phasor Analysis and Transmission Line Model (TLM) for different mass flow and values of optimum frequency and phase angles were predicted. They were compared with experimental data from the PTC for different configurations of the Inertance tube/reservoir at various frequencies and charge pressures. These studies were carried out to characterise an existing cryocooler and design an optimised phase shifter with the aim of improving the performance with respect to specific power input.

A pollen-specific RALF from tomato that regulates pollen tube elongation.

PubMed

Covey, Paul A; Subbaiah, Chalivendra C; Parsons, Ronald L; Pearce, Gregory; Lay, Fung T; Anderson, Marilyn A; Ryan, Clarence A; Bedinger, Patricia A

2010-06-01

Rapid Alkalinization Factors (RALFs) are plant peptides that rapidly increase the pH of plant suspension cell culture medium and inhibit root growth. A pollen-specific tomato (Solanum lycopersicum) RALF (SlPRALF) has been identified. The SlPRALF gene encodes a preproprotein that appears to be processed and released from the pollen tube as an active peptide. A synthetic SlPRALF peptide based on the putative active peptide did not affect pollen hydration or viability but inhibited the elongation of normal pollen tubes in an in vitro growth system. Inhibitory effects of SlPRALF were detectable at concentrations as low as 10 nm, and complete inhibition was observed at 1 mum peptide. At least 10-fold higher levels of alkSlPRALF, which lacks disulfide bonds, were required to see similar effects. A greater effect of peptide was observed in low-pH-buffered medium. Inhibition of pollen tube elongation was reversible if peptide was removed within 15 min of exposure. Addition of 100 nm SlPRALF to actively growing pollen tubes inhibited further elongation until tubes were 40 to 60 mum in length, after which pollen tubes became resistant to the peptide. The onset of resistance correlated with the timing of the exit of the male germ unit from the pollen grain into the tube. Thus, exogenous SlPRALF acts as a negative regulator of pollen tube elongation within a specific developmental window.

Implementation of biological variation-based analytical performance specifications in the laboratory: Stringent evaluation of Improvacutor blood collection tubes.

PubMed

Chung, Hee-Jung; Song, Yoon Kyung; Hong, Sung Kuk; Hwang, Sang-Hyun; Seo, Hee Seung; Whang, Dong Hee; Nam, Myung-Hyun; Lee, Do Hoon

2017-01-01

Recently, because the quality of laboratory analyses has increased along with the need for quality improvement, several external quality control bodies have adapted performance specifications using the Desirable Biological Variation Database, termed "Ricos goals"; these criteria are more stringent than those presented in CLIA 88. In this study, we aimed to validate newly introduced serum separator tubes, Improvacutor, for routine clinical chemistry testing in accordance with Ricos goals and CLIA 88. Blood samples were collected from 100 volunteers into three types of serum vacuum tubes: Greiner Vacuette, Becton Dickinson (BD) Vacutainer, and Improve Improvacutor. The samples were subjected to 16 routine chemistry tests using a TBA-200fr NEO chemistry autoanalyzer. In the comparison analysis, all 16 test results were acceptable according to CLIA 88. However, in the comparison of Improve and BD tubes, creatinine showed 4.31% (+0.08 μmol/L) bias. This slightly exceeded the Desirable Specification for Inaccuracy Ricos limit of ±3.96%, but still satisfied the CLIS88 limit of ±26.52 μmol/L. The remaining 15 analytes performed acceptably according to the Desirable Specifications of Ricos. The correlation coefficient of 12 analytes was greater than 0.95 in Passing-Bablok regression analysis among the three tubes, but was lower for four analytes: calcium, sodium, potassium, and chloride. In the stability assay, only potassium tested in the Greiner tube revealed a larger positive bias (2.18%) than the Ricos Desirable Specification for Inaccuracy based on biologic variation (1.8%). The BD tube also showed a positive bias of 1.74%, whereas the new Improve tube showed the smallest positive bias of 1.17% in potassium level after 72 h storage. Thus, the results of this study demonstrate that recently introduced analytical performance specifications based on components of biological variation (Rico's goal) could be extended to criterion for performance evaluation and applied.

Assessing a nephrology-focused YouTube channel's potential to educate health care providers.

PubMed

Desai, Tejas; Sanghani, Vivek; Fang, Xiangming; Christiano, Cynthia; Ferris, Maria

2013-01-01

YouTube has emerged as a potential teaching tool. Studies of the teaching potential of YouTube videos have not addressed health care provider (HCP) satisfaction; a necessary prerequisite for any teaching tool. We conducted a 4-month investigation to determine HCP satisfaction with a nephrology-specific YouTube channel. The Nephrology On-Demand YouTube channel was analyzed from January 1 through April 30, 2011. Sixty-minute nephrology lectures at East Carolina University were compressed into 10-minute videos and uploaded to the channel. HCPs were asked to answer a 5-point Likert questionnaire regarding the accuracy, currency, objectivity and usefulness of the digital format of the teaching videos. Means, standard deviations and 2-sided chi-square testing were performed to analyze responses. Over 80% of HCPs considered the YouTube channel to be accurate, current and objective. A similar percentage considered the digital format useful despite the compression of videos and lack of audio. The nephrology-specific YouTube channel has the potential to educate HCPs of various training backgrounds. Additional studies are required to determine if such specialty-specific channels can improve knowledge acquisition and retention.

NASA Subsonic Jet Transport Noise Reduction Research

DTIC Science & Technology

2000-09-01

optical and acoustical interference. Figure 7 shows the concept and data from the installation of arrays of Herschel- Quincke tubes in the duct...tube row 16 tube row Herschel- Quincke Tube Tube length 12.5cm d = 3.8cm L = 9.2cm 2250 2350 2450 2500...Blade passage frequency, Hz R el at iv e p o w er , d B JT15D Turbofan Engine 4 d B Figure 7. Application of Herschel- Quincke tubes for

Numerical study of a gas coupled VM-PT hybrid cryocooler using 3He as the working fluid

NASA Astrophysics Data System (ADS)

Wang, J.; Pan, C. Z.; Zhang, T.; Wang, J. J.; Zhou, Y.

2017-12-01

The two-stage Vuilleumier gas-coupling pulse tube cryocooler (VM-PT) is one kind of novel low-frequency cryocoolers. In this gas-coupled form, the single stage Vuilleumier cryocooler serves as both pressure wave generator and a pre-cooler for coaxial pulse tube. Compared with the most commercialized GM and GM pulse tube cryocooler, the two-stage VM-PT cryocooler is characterized by its high stability, compact size and thermal actuation which are indispensable for space application. It has already been verified experimentally that this cryocooler can obtain 9.75mW@4.2K and the lowest no-load temperature 3.39K when 4He as the working fluid. However, such refrigerating capacity seems not enough for further application. 3He as a more potential substitution of 4He has better physical properties to improve performance, which has been studied in GM type and Stirling pulse tube cryocooler. For further optimization, a numerical study on the specific performance of two-stage VM-PT cryocooler using 3He is carried out in the present paper though Sage software. Working at the frequency of 1.0Hz and the pressure of 0.8MPa, the two-stage VM-PT cryocooler with 3He obtained 50mW@4.06K. The usage of 3He was 0.0038kg, about 30L under STP. At 4.2K, using 3He can obtain 58mW cooling power and 0.49% relative Carnot efficiency, about 1.6 times higher than using 4He.

Method of making large area conformable shape structures for detector/sensor applications using glass drawing technique and postprocessing

DOEpatents

Ivanov, Ilia N [Knoxville, TN; Simpson, John T [Clinton, IN

2012-01-24

A method of making a large area conformable shape structure comprises drawing a plurality of tubes to form a plurality of drawn tubes, and cutting the plurality of drawn tubes into cut drawn tubes of a predetermined shape. The cut drawn tubes have a first end and a second end along the longitudinal direction of the cut drawn tubes. The method further comprises conforming the first end of the cut drawn tubes into a predetermined curve to form the large area conformable shape structure, wherein the cut drawn tubes contain a material.

A noiseless, kHz frame rate imaging detector for AO wavefront sensors based on MCPs read out with the Medipix2 CMOS pixel chip

NASA Astrophysics Data System (ADS)

Vallerga, J. V.; McPhate, J. B.; Tremsin, A. S.; Siegmund, O. H. W.; Mikulec, B.; Clark, A. G.

2004-12-01

Future wavefront sensors in adaptive optics (AO) systems for the next generation of large telescopes (> 30 m diameter) will require large formats (512x512) , kHz frame rates, low readout noise (<3 electrons) and high optical QE. The current generation of CCDs cannot achieve the first three of these specifications simultaneously. We present a detector scheme that can meet the first three requirements with an optical QE > 40%. This detector consists of a vacuum tube with a proximity focused GaAs photocathode whose photoelectrons are amplified by microchannel plates and the resulting output charge cloud counted by a pixelated CMOS application specific integrated circuit (ASIC) called the Medipix2 (http://medipix.web.cern.ch/MEDIPIX/). Each 55 micron square pixel of the Medipix2 chip has an amplifier, discriminator and 14 bit counter and the 256x256 array can be read out in 287 microseconds. The chip is 3 side abuttable so a 512x512 array is feasible in one vacuum tube. We will present the first results with an open-faced, demountable version of the detector where we have mounted a pair of MCPs 500 microns above a Medipix2 readout inside a vacuum chamber and illuminated it with UV light. The results include: flat field response, spatial resolution, spatial linearity on the sub-pixel level and global event counting rate. We will also discuss the vacuum tube design and the fabrication issues associated with the Medipix2 surviving the tube making process.

Progress in Development of a Miniature Pulse Tube Cooler for Space Applications

NASA Astrophysics Data System (ADS)

Gibson, A. S.; Hunt, R.; Charles, I.; Duband, L.; Crook, M. R.; Orlowska, A. H.; Bradshaw, T. W.; Linder, M.

2004-06-01

A pulse tube cryocooler is under development for high-reliability spacecraft applications. Recent developments in the assembly and verification of a Miniature Pulse Tube Cooler (MPTC) are presented, including the latest data from the test program. Details of advances related to the compressor, pulse tube and electronics are discussed. The pulse tube cooler achieves high efficiency, optimised through an extensive process of breadboard testing and analysis and is now approaching a more mature Engineering Model (EM) status. A representative pulse tube cold finger has been verified with respect to design changes incorporated following the breadboard test phase. Mass, heat lift and parasitic losses have been improved. A mechanical system mass of 3.1 kg has been achieved. Cold finger tests have demonstrated the ability of the pulse tube to lift 1.5 W at 80 K and to reach <50 K for a PV-work of 25 W. The useful range of operation for the cooler extends below 60 K, where test results indicate 600 mW of heat lift capability.

Pulse tube cryocoolers for industrial applications

NASA Astrophysics Data System (ADS)

Martin, J. L.; Martin, C. M.

2002-05-01

Stirling-type, high frequency pulse tube cryocoolers have received considerable interest in the past decade due to their high reliability, low vibration, and high efficiency. Most of the previous development of Stirling-type pulse tube cryocoolers has focused on relatively small machines with cooling powers in the range of 5 W at 80 K. In this paper, we discuss the extension of Stirling-type pulse tube cryocoolers to higher capacities for industrial applications. Mesoscopic Devices is currently developing a family of pulse tube cryocoolers with capacities ranging from 10 W at 80 K to over 1300 W at 80 K. Each of these machines uses a 50 or 60 Hz moving magnet linear compressor, inertance tube phase shift network, and either in-line or coaxial pulse tube expanders. With input powers of up to 20 kW, these large cryocoolers require different heat exchanger and regenerator designs to efficiently exchange heat with the load and environment. Design and construction techniques for the expander and heat exchangers are discussed.

Ultra high vacuum seal arrangement

DOEpatents

Flaherty, Robert

1981-01-01

Arrangement for demountably sealing two concentric metallic tubes in an ultra high vacuum system which facilitates remote actuation. A tubular seal includes integral spaced lips which circumferentially engage the metallic tubes. The lips plastically deform the metallic tubes by mechanical forces resulting from a martensite to austenite transformation of the tubular seal upon application of a predetermined temperature. The sealing force is released upon application of another temperature which causes a transformation from the stronger austenite to the weaker martensite. Use of a dual acting sealing ring and driving ring circumferentially contacting the sealing ring is particularly applicable to sealing larger diameter concentric metallic members.

Structural crashworthiness; International Symposium, 1st, University of Liverpool, Liverpool, England, September 14-16, 1983, Invited Lectures

NASA Astrophysics Data System (ADS)

Jones, N.; Wierzbicki, T.

The application of solid, structural, and experimental mechanics to predict the crumpling behavior and energy absorption of thin-walled structures under quasi-static compression and various dynamic crash loadings is examined in reviews of current research. Both fundamental aspects and specific problems in the design of crashworthy aircraft, automobiles, railroad cars, ships, and offshore installations are considered. Topics discussed include laterally compressed metal tubes as impact-energy absorbers, crushing behavior of plate intersections, axial crushing of fiber-reinforced composite tubes, finite-element analysis of structural crashworthiness in the automotive and aerospace industries, crash behavior of aircraft fuselage structures, aircraft crash analysis, ship collisions, and structural damage in airship and rolling-stock collisions. Photographs, graphs, drawings, and diagrams are provided.

The structural characteristics of inflatable beams

NASA Astrophysics Data System (ADS)

Wicker, William J.

1992-08-01

Two inflatable beams are designed and fabricated from polyethylene of ultrahigh molecular weight, and the structures are tested against similar composite and metal-alloy tubes. Specific attention is given to the choice of material that insures material stiffness, good strength-to-weight ratio, creep resistance, and durability. A cloth beam is built from a commercial extended-chain polyethylene fiber, and the inflated beams are tested by means of three- and four-point loading to measure bending and shear deformation. Comparing geometrically similar structures shows that the fabric beams can be about 35 percent as stiff as aluminum for small deflections. The inflatable beams have elastic stiffness coefficients five and two times higher than those for nylon and polyester tubes, respectively. Inflatable structures are concluded to hold promise for lightweight aerospace applications which demand small storage areas.

Social Media and Social Networking Applications for Teaching and Learning

ERIC Educational Resources Information Center

Yeo, Michelle Mei Ling

2014-01-01

This paper aims to better understand the experiences of the youth and the educators with the tapping of social media like YouTube videos and the social networking application of Facebook for teaching and learning. This paper is interested in appropriating the benefits of leveraging of social media and networking applications like YouTube and…

20--500 watt AMTEC auxiliary electric power system

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

Ivanenok, J.F. III; Sievers, R.K.

1996-12-31

Numerous design studies have been completed on Alkali Metal Thermal to Electric Converter (AMTEC) power systems for space applications demonstrating their substantial increase in performance. Recently design studies have been initiated to couple AMTEC power conversion with fossil fueled combustion systems. This paper describes the results of a Phase 1 SBIR effort to design an innovative, efficient, reliable, long life AMTEC Auxiliary Electric Power System (AEPS) for remote site applications (20--500 watts). The concept uses high voltage AMTEC cells, each containing 7 to 9 small electrolyte tubes, integrated with a combustor and recuperator. These multi-tube AMTEC cells are low cost,more » reliable, long life static converters. AMTEC technology is ideal for auxiliary electric power supplies that must operate reliably over a broad range of temperatures, fuel sources, power levels, and operational specifications. The simplicity, efficiency (20% systems) and modularity of this technology allow it to fill applications as varied as light-weight backpacks, remote site power supplies, and military base power. Phase 1 demonstrated the feasibility of a 20% system design, and showed that the development needs to focus on identifying long life AMTEC cell components, determining the AMTEC cell and system reliability, and demonstrating that a 20 watt AMTEC system is 3--5 times more efficient than existing systems for the same application.« less

Albumin testing in urine using a smart-phone

PubMed Central

Coskun, Ahmet F.; Nagi, Richie; Sadeghi, Kayvon; Phillips, Stephen; Ozcan, Aydogan

2013-01-01

We demonstrate a digital sensing platform, termed Albumin Tester, running on a smart-phone that images and automatically analyses fluorescent assays confined within disposable test tubes for sensitive and specific detection of albumin in urine. This light-weight and compact Albumin Tester attachment, weighing approximately 148 grams, is mechanically installed on the existing camera unit of a smart-phone, where test and control tubes are inserted from the side and are excited by a battery powered laser diode. This excitation beam, after probing the sample of interest located within the test tube, interacts with the control tube, and the resulting fluorescent emission is collected perpendicular to the direction of the excitation, where the cellphone camera captures the images of the fluorescent tubes through the use of an external plastic lens that is inserted between the sample and the camera lens. The acquired fluorescent images of the sample and control tubes are digitally processed within one second through an Android application running on the same cellphone for quantification of albumin concentration in urine specimen of interest. Using a simple sample preparation approach which takes ~ 5 minutes per test (including the incubation time), we experimentally confirmed the detection limit of our sensing platform as 5–10 μg/mL (which is more than 3 times lower than clinically accepted normal range) in buffer as well as urine samples. This automated albumin testing tool running on a smart-phone could be useful for early diagnosis of kidney disease or for monitoring of chronic patients, especially those suffering from diabetes, hypertension, and/or cardiovascular diseases. PMID:23995895

Economic efficiency of application of innovative materials and structures in high-rise construction

NASA Astrophysics Data System (ADS)

Golov, Roman; Dikareva, Varvara; Gorshkov, Roman; Agarkov, Anatoly

2018-03-01

The article is devoted to the analysis of technical and economic efficiency of application of tube confined concrete structures in high-rise construction. The study of comparative costs of materials with the use of different supporting columns was carried out. The main design, operational, technological and economic advantages of the tube confined concrete technology were evaluated, conclusions were drawn about the high strength and deformation properties of axial compression of steel tubes filled with high-strength concrete. The efficiency of the tube confined concrete use is substantiated, which depends mainly on the scale factor and percentage of reinforcement affecting its load-bearing capacity.

Proceedings of the International Cryocooler Conference (7th) Held in Santa Fe, New Mexico on 17-19 November 1992. Part 2,

DTIC Science & Technology

1993-04-01

presentations. The topics included Cryoccoler Testing and Modeling , Space and Long Life Applications, Stirling Cryocoolers , Pulse Tube Refrigerators, Novel...Equation (12), derived in the present study can also be used to develop a linear network model of Stirling 1" or pulse - tube cryocoolers by...Applications, Stirling Cryocoolers , Pulse Tube Refrigerators, Novel Concepts and Component Development, Low Temperature Regenerator Development, and J-T and

Sensitive, microliter PCR with consensus degenerate primers for Epstein Barr virus amplification

PubMed Central

Oh, Kyudam; Pak, Nikita; Saunders, D. Curtis; Conrardy, Christina; Landers, James P.; Tong, Suxiang; Forest, Craig R.

2016-01-01

Sensitive identification of the etiology of viral diseases is key to implementing appropriate prevention and treatment. The gold standard for virus identification is the polymerase chain reaction (PCR), a technique that allows for highly specific and sensitive detection of pathogens by exponentially amplifying a specific region of DNA from as little as a single copy through thermocycling a biochemical cocktail. Today, molecular biology laboratories use commercial instruments that operate in 0.5–2 h/analysis using reaction volumes of 5–50 μL contained within polymer tubes or chambers. Towards reducing this volume and maintaining performance, we present a semi-quantitative, systematic experimental study of how PCR yield is affected by tube/chamber substrate, surface-area-to-volume ratio (SA:V), and passivation methods. We perform PCR experiments using traditional PCR tubes as well as using disposable polymer microchips with 1 μL reaction volumes thermocycled using water baths. We report the first oil encapsulation microfluidic PCR method without fluid flow and its application to the first microfluidic amplification of Epstein Barr virus using consensus degenerate primers, a powerful and broad PCR method to screen for both known and novel members of a viral family. The limit of detection is measured as 140 starting copies of DNA from a starting concentration of 3×105 copies/mL, regarded as an accepted sensitivity threshold for diagnostic purposes, and reaction specificity was improved as compared to conventional methods. Also notable, these experiments were conducted with conventional reagent concentrations, rather than commonly spiked enzyme and/or template mixtures. This experimental study of the effects of substrate, SA:V, and passivation, together with sensitive and specific microfluidic PCR with consensus degenerate primers represent advances towards lower cost and higher throughput pathogen screening. PMID:23080522

Design and fabrication of an IPMC-embedded tube for minimally invasive surgery applications

NASA Astrophysics Data System (ADS)

Liu, Jiayu; Wang, Yanjie; Zhao, Dongxu; Zhang, Chi; Chen, Hualing; Li, Dichen

2014-03-01

Minimally Invasive Surgery (MIS) is receiving much attention for a number of reasons, including less trauma, faster recovery and enhanced precision. The traditional robotic actuators do not have the capabilities required to fulfill the demand for new applications in MIS. Ionic Polymer-Metal Composite (IPMC), one of the most promising smart materials, has extensive desirable characteristics such as low actuation voltage, large bending deformation and high functionality. Compared with traditional actuators, IPMCs can mimic biological muscle and are highly promising for actuation in robotic surgery. In this paper, a new approach which involves molding and integrating IPMC actuators into a soft silicone tube to create an active actuating tube capable of multi-degree-of-freedom motion is presented. First, according to the structure and performance requirements of the actuating tube, the biaxial bending IPMC actuators fabricated by using solution casting method have been implemented. The silicone was cured at a suitable temperature to form a flexible tube using molds fabricated by 3D Printing technology. Then an assembly based fabrication process was used to mold or integrate biaxial bending IPMC actuators into the soft silicone material to create an active control tube. The IPMC-embedded tube can generate multi-degree-of-freedom motions by controlling each IPMC actuator. Furthermore, the basic performance of the actuators was analyzed, including the displacement and the response speed. Experimental results indicate that IPMC-embedded tubes are promising for applications in MIS.

76 FR 11757 - Drill Pipe From the People's Republic of China: Antidumping Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-03

... are finished drill pipe and drill collars without regard to the specific chemistry of the steel (i.e... included are unfinished drill collars (including all drill collar green tubes) and unfinished drill pipe (including drill pipe green tubes, which are tubes meeting the following description: seamless tubes with an...

Additive manufacturing of patient-specific tubular continuum manipulators

NASA Astrophysics Data System (ADS)

Amanov, Ernar; Nguyen, Thien-Dang; Burgner-Kahrs, Jessica

2015-03-01

Tubular continuum robots, which are composed of multiple concentric, precurved, elastic tubes, provide more dexterity than traditional surgical instruments at the same diameter. The tubes can be precurved such that the resulting manipulator fulfills surgical task requirements. Up to now the only material used for the component tubes of those manipulators is NiTi, a super-elastic shape-memory alloy of nickel and titan. NiTi is a cost-intensive material and fabrication processes are complex, requiring (proprietary) technology, e.g. for shape setting. In this paper, we evaluate component tubes made of 3 different thermoplastic materials (PLA, PCL and nylon) using fused filament fabrication technology (3D printing). This enables quick and cost-effective production of custom, patient-specific continuum manipulators, produced on site on demand. Stress-strain and deformation characteristics are evaluated experimentally for 16 fabricated tubes of each thermoplastic with diameters and shapes equivalent to those of NiTi tubes. Tubes made of PCL and nylon exhibit properties comparable to those made of NiTi. We further demonstrate a tubular continuum manipulator composed of 3 nylon tubes in a transnasal, transsphenoidal skull base surgery scenario in vitro.

A microfluidic tubing method and its application for controlled synthesis of polymeric nanoparticles.

PubMed

Wang, Jidong; Chen, Wenwen; Sun, Jiashu; Liu, Chao; Yin, Qifang; Zhang, Lu; Xianyu, Yunlei; Shi, Xinghua; Hu, Guoqing; Jiang, Xingyu

2014-05-21

This report describes a straightforward but robust tubing method for connecting polydimethylsiloxane (PDMS) microfluidic devices to external equipment. The interconnection is irreversible and can sustain a pressure of up to 4.5 MPa that is characterized experimentally and theoretically. To demonstrate applications of this high-pressure tubing technique, we fabricate a semicircular microfluidic channel to implement a high-throughput, size-controlled synthesis of poly(lactic-co-glycolic acid) (PLGA) nanoparticles ranging from 55 to 135 nm in diameter. This microfluidic device allows for a total flow rate of 410 mL h(-1), resulting in enhanced convective mixing which can be utilized to precipitate small size nanoparticles with a good dispersion. We expect that this tubing technique would be widely used in microfluidic chips for nanoparticle synthesis, cell manipulation, and potentially nanofluidic applications.

Thin layer chromatography residue applicator sampler

DOEpatents

Nunes, Peter J [Danville, CA; Kelly, Fredrick R [Modesto, CA; Haas, Jeffrey S [San Ramon, CA; Andresen, Brian D [Livermore, CA

2007-07-24

A thin layer chromatograph residue applicator sampler. The residue applicator sampler provides for rapid analysis of samples containing high explosives, chemical warfare, and other analyses of interest under field conditions. This satisfied the need for a field-deployable, small, hand-held, all-in-one device for efficient sampling, sample dissolution, and sample application to an analytical technique. The residue applicator sampler includes a sampling sponge that is resistant to most chemicals and is fastened via a plastic handle in a hermetically sealed tube containing a known amount of solvent. Upon use, the wetted sponge is removed from the sealed tube and used as a swiping device across an environmental sample. The sponge is then replaced in the hermetically sealed tube where the sample remains contained and dissolved in the solvent. A small pipette tip is removably contained in the hermetically sealed tube. The sponge is removed and placed into the pipette tip where a squeezing-out of the dissolved sample from the sponge into the pipette tip results in a droplet captured in a vial for later instrumental analysis, or applied directly to a thin layer chromatography plate for immediate analysis.

Design package for concentrating solar collector panels

NASA Technical Reports Server (NTRS)

1978-01-01

Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The collector is a water/glycol/working fluid type, with a dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, and fiber glass insulation. It weights 98 pounds. A collector assembly includes four collector units within a tracking mount array.

Deciphering the molecular mechanisms underlying sea urchin reversible adhesion: A quantitative proteomics approach.

PubMed

Lebesgue, Nicolas; da Costa, Gonçalo; Ribeiro, Raquel Mesquita; Ribeiro-Silva, Cristina; Martins, Gabriel G; Matranga, Valeria; Scholten, Arjen; Cordeiro, Carlos; Heck, Albert J R; Santos, Romana

2016-04-14

Marine bioadhesives have unmatched performances in wet environments, being an inspiration for biomedical applications. In sea urchins specialized adhesive organs, tube feet, mediate reversible adhesion, being composed by a disc, producing adhesive and de-adhesive secretions, and a motile stem. After tube foot detachment, the secreted adhesive remains bound to the substratum as a footprint. Sea urchin adhesive is composed by proteins and sugars, but so far only one protein, Nectin, was shown to be over-expressed as a transcript in tube feet discs, suggesting its involvement in sea urchin adhesion. Here we use high-resolution quantitative mass-spectrometry to perform the first study combining the analysis of the differential proteome of an adhesive organ, with the proteome of its secreted adhesive. This strategy allowed us to identify 163 highly over-expressed disc proteins, specifically involved in sea urchin reversible adhesion; to find that 70% of the secreted adhesive components fall within five protein groups, involved in exocytosis and microbial protection; and to provide evidences that Nectin is not only highly expressed in tube feet discs but is an actual component of the adhesive. These results give an unprecedented insight into the molecular mechanisms underlying sea urchin adhesion, and opening new doors to develop wet-reliable, reversible, and ecological biomimetic adhesives. Sea urchins attach strongly but in a reversible manner to substratum, being a valuable source of inspiration for industrial and biomedical applications. Yet, the molecular mechanisms governing reversible adhesion are still poorly studied delaying the engineering of biomimetic adhesives. We used the latest mass spectrometry techniques to analyze the differential proteome of an adhesive organ and the proteome of its secreted adhesive, allowing us to uncover the key players in sea urchin reversible adhesion. We demonstrate, that Nectin, a protein previously pointed out as potentially involved in sea urchin adhesion, is not only highly expressed in tube feet discs, but is a genuine component of the secreted adhesive. Copyright © 2016 Elsevier B.V. All rights reserved.

Low thermal flux glass-fiber tubing for cryogenic service

NASA Technical Reports Server (NTRS)

Hall, C. A.; Spond, D. E.

1977-01-01

This paper describes analytical techniques, fabrication development, and test results for composite tubing that has many applications in aerospace and commercial cryogenic installations. Metal liner fabrication is discussed in detail with attention given to resistance-welded liners, fusion-welded liners, chem-milled tubing liners, joining tube liners and end fittings, heat treatment and leak checks. Composite overwrapping, a second method of tubing fabrication, is also discussed. Test programs and analytical correlation are considered along with composite tubing advantages such as minimum weight, thermal efficiency and safety and reliability.

Device and method for shortening reactor process tubes

DOEpatents

Frantz, C.E.; Alexander, W.K.; Lander, W.E.B.

A device and method are described for in situ shortening of nuclear reactor zirconium alloy process tubes which have grown as a result of radiation exposure. An upsetting technique is utilized which involves inductively heating a short band of a process tube with simultaneous application of an axial load sufficient to cause upsetting with an attendant decrease in length of the process tube.

Design and performance of a straw tube drift chamber

NASA Astrophysics Data System (ADS)

Oh, S. H.; Wesson, D. K.; Cooke, J.; Goshaw, A. T.; Robertson, W. J.; Walker, W. D.

1991-06-01

The design and performance of the straw drift chambers used in E735 is reported. The chambers are constructed from 2.5 cm radius aluminized mylar straw tubes with wall thickness less than 0.2 mm. Also, presented are the results of tests with 2 mm radius straw tubes. The small tube has a direct detector application at the Superconducting Super Collider.

Quasi-static axial crushes on woven jute/polyester AA6063T52 composite tubes

NASA Astrophysics Data System (ADS)

Othman, A.; Ismail, AE

2018-04-01

Quasi-static axial loading have been studied in this paper to determine the behaviour of jute/polyester wrapped on aluminium alloy 6063T52. The filler material also was include into crush box specimen, which is polyurethane (PU) and polystyrene (PE) rigid foam at ranging 40 and 45 kg/m3 densities. All specimen profile was fabricated using hand layup techniques and the length of each specimen were fixed at 100 mm as well as diameter and width of the tube at 50.8 mm. The two types of tubular cross-section were studied of round and square thin-walled profiles and the angle of fibre at 450 were analysed for four layers. Thin walled of aluminium was 1.9 mm and end frontal of each specimen of composite were chamfered at 450 to prevent catastrophic failure mode. The specific absorbed energy (SEA) and crush force efficiency (CFE) were analyses for each specimen to see the behaviour on jute/polyester wrapped on metallic structure can give influence the energy management for automotive application. Result show that the four layers’ jute/polyester with filler material show significant value in term of specific absorbed energy compared empty and polyurethane profiles higher 26.66% for empty and 15.19% compared to polyurethane profiles. It has been found that the thin walled square profile of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 27.42% to 13.13% than empty and polyurethane (PU) foam tubes. An introduce filler material onto thin walled composite profiles gave major advantage increases the mean axial load of 31.87% from 32.94 kN to 48.35 kN from empty to polystyrene thin walled round jute/polyester profiles and 31.7% from 23.11 KN to 33.84 kN from empty to polystyrene thin walled square jute/polyester profiles. Failure mechanisms of the axially loaded composite tubes were also observed and discussed.

[Research on the application of "H shaped" single-tube double-lumen drainage tube in the treatment of chronic subdural hematoma].

PubMed

Sun, T; Jiang, Z Q; Zhang, S J; Lou, F Y; Zhang, T; Han, Y; Zheng, X L

2016-04-05

To explore the effect of chronic subdural hematoma external drainage surgery using self-made "H shaped" flush type single-tube double-lumen drainage tube. There were 56 cases chosen from the First Affiliated Hospital of Bengbu Medical College between Jan 2013 and Aug 2015. These patients with unilateral chronic subdural hematoma requiring surgery to place drilling external drainage catheter were randomly divided into group A (21 cases, using self-made single-tube double lumen "H shaped" drainage tube) and group B (35 cases, traditional silicone drainage tube), then the residual liquid volume after drainage on the first day, the days that the tube stay in body and the residual fluid volume after removing the tube were compared between the two groups. The residual liquid volume after drainage on the first day in group A was (23±15)ml, in group B was (31±15)ml. The days that the tube stay in body in group A was (2.7±1.0)d, in group B was (3.3±1.1)d, the two groups had statistical differences (P<0.05). The residual fluid volume after removing the tube in group A was (13±7) ml, in group B was (16±8)ml, but the data in these two groups had no significantly statistical differences (P>0.05). The effect of self-made "H shaped" flush type single-tube double-lumen drainage tube in the drainage of chronic subdural hematoma drainage is good, with short tube stay in the body; therefore, it is a safe and effective way to treat chronic subdural hematoma, and is worthy of clinical application.

Comparison of polyurethane foam and XAD-2 sampling matrices to measure airborne organophosphorus pesticides and their oxygen analogs in an agricultural community

PubMed Central

Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Tchong-French, Maria; Yu, Jianbo

2013-01-01

Side-by-side active air sampling for the organophosphorus (OP) pesticide, chlorpyrifos (CPF) and its oxygen analog, chlorpyrifos-oxon (CPF-O) was conducted with two recommended air sampling matrices: OSHA Versatile Sampling (OVS) tubes with XAD-2 resin, polyurethane foam (PUF) tubes, and passive PUF deposition disks. The study compared the proportion of artificially transformed CPF-O in the laboratory and in the field during a tree fruit application in Washington State. Lab results demonstrated that the NIOSH-recommended OVS tubes artificially transformed up to 32% of CPF to CPF-O during the sampling process, whereas PUF tubes had little to no artificial transformation (≤ 0.1%). In the field, the proportion of CPF-O in the sample was significantly higher on OVS tubes than on PUF tubes (p < 0.001), confirming that OVS tubes were converting a significant portion of CPF to CPF-O. In addition, PUF tubes reported measurable levels CPF-O in the field even when no artificial transformation was expected. We conclude that the PUF matrix is the superior sampling medium for OP oxygen analogs when compared to XAD-2 resin. Community-located PUF tube samples 24 hours post-application had considerably higher levels CPF-O (16–21 ng/m3) than near field samples during application (2–14 ng/m3), suggesting that the oxygen analog is volatile and formed during atmospheric transport. It is recommended that worker and community risk assessments begin to take into consideration the presence of the more toxic oxygen analogs when measuring for OP pesticide mixtures. PMID:23466277

Metal vapor laser including hot electrodes and integral wick

DOEpatents

Ault, Earl R.; Alger, Terry W.

1995-01-01

A metal vapor laser, specifically one utilizing copper vapor, is disclosed herein. This laser utilizes a plasma tube assembly including a thermally insulated plasma tube containing a specific metal, e.g., copper, and a buffer gas therein. The laser also utilizes means including hot electrodes located at opposite ends of the plasma tube for electrically exciting the metal vapor and heating its interior to a sufficiently high temperature to cause the metal contained therein to vaporize and for subjecting the vapor to an electrical discharge excitation in order to lase. The laser also utilizes external wicking arrangements, that is, wicking arrangements located outside the plasma tube.

Metal vapor laser including hot electrodes and integral wick

DOEpatents

Ault, E.R.; Alger, T.W.

1995-03-07

A metal vapor laser, specifically one utilizing copper vapor, is disclosed herein. This laser utilizes a plasma tube assembly including a thermally insulated plasma tube containing a specific metal, e.g., copper, and a buffer gas therein. The laser also utilizes means including hot electrodes located at opposite ends of the plasma tube for electrically exciting the metal vapor and heating its interior to a sufficiently high temperature to cause the metal contained therein to vaporize and for subjecting the vapor to an electrical discharge excitation in order to lase. The laser also utilizes external wicking arrangements, that is, wicking arrangements located outside the plasma tube. 5 figs.

Method for morphological control and encapsulation of materials for electronics and energy applications

DOEpatents

Ivanov, Ilia N.; Simpson, John T.

2013-06-11

An electronic device comprises a drawn glass tube having opposing ends, a semiconductive material disposed inside of the drawn glass tube, and a first electrode and a second electrode disposed at the opposing ends of the drawn glass tube. A method of making an electrical device comprises disposing a semiconductive material inside of a glass tube, and drawing the glass tube with the semiconductive material disposed therein to form a drawn glass tube. The method of making an electrical device also comprises disposing a first electrode and a second electrode on the opposing ends of the drawn glass tube to form an electric device.

Method for uniformly bending conduits

DOEpatents

Dekanich, S.J.

1984-04-27

The present invention is directed to a method for bending metal tubing through various radii while maintaining uniform cross section of the tubing. The present invention is practical by filling the tubing to a sufficient level with water, freezing the water to ice and bending the ice-filled tubing in a cooled die to the desired radius. The use of the ice as a filler material provides uniform cross-sectional bends of the tubing and upon removal of the ice provides an uncontaminated interior of the tubing which will enable it to be used in its intended application without encountering residual contaminants in the tubing due to the presence of the filler material.

76 FR 6762 - Drill Pipe From the People's Republic of China: Amended Final Determination of Critical...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-08

... the specific chemistry of the steel (i.e., carbon, stainless steel, or other alloy steel), and without... collar green tubes) and unfinished drill pipe (including drill pipe green tubes, which are tubes meeting...

29 CFR 1926.450 - Scope, application and definitions applicable to this subpart.

Code of Federal Regulations, 2010 CFR

2010-07-01

... one who is capable of identifying existing and predictable hazards in the surroundings or working... locking together the tubes of a tube and coupler scaffold. Crawling board (chicken ladder) means a... alternative designs, materials or methods to protect against a hazard which the employer can demonstrate will...

Device and method for shortening reactor process tubes

DOEpatents

Frantz, Charles E.; Alexander, William K.; Lander, Walter E. B.

1980-01-01

This disclosure describes a device and method for in situ shortening of nuclear reactor zirconium alloy process tubes which have grown as a result of radiation exposure. An upsetting technique is utilized which involves inductively heating a short band of a process tube with simultaneous application of an axial load sufficient to cause upsetting with an attendant decrease in length of the process tube.

Literature search for ceramic vacuum tubes

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

Cannon, W.

1977-01-12

The NTIS and Engineering Index files were searched for citations relating to Ceramic and/or Metal Electron Tubes and High Temperature Electronics. A total of 24 citations were found relating directly to ceramic tubes and 24 to high temperature electronics. A search for electron tubes in general was examined for high temperature applications and 39 were obtained. Computer printouts of the abstracts are included in appendices. (MHR)

Laparoscopic insertion of the Moss feeding tube.

PubMed

Albrink, M H; Hagan, K; Rosemurgy, A S

1993-12-01

Placement of enteral feeding tubes is an important part of a surgeon's skill base. Surgical insertion of feeding tubes has been performed safely for many years with very few modifications. With the recent surge in interest and applicability of other laparoscopic procedures, it is well within the skills of the average laparoscopic surgeon to insert feeding tubes. We describe herein a simple technique for the insertion of the Moss feeding tube. The procedure described has a minimum of invasion, along with simplicity, safety, and accuracy.

The successful use of simple tube duodenostomy in large duodenal perforations from varied etiologies

PubMed Central

Kutlu, Onur C.; Garcia, Steven; Dissanaike, Sharmila

2012-01-01

INTRODUCTION Tube decompression of the duodenum is an old but underutilized technique known to decrease morbidity and mortality in patients with difficult to manage duodenal injuries. Broad arrays of techniques have been described in the literature and are reviewed, but most are complex procedures not appropriate for the management of an unstable patient. PRESENTATION OF CASE In this paper we describe the technique of tube duodenostomy and the successful application in three cases of large defects (>3 cm) which two of these cases had failed previous repair attempts. The defects were caused by very different etiologies, including blunt trauma, peptic ulcer disease and erosion from cancer. All were finally managed by application of tube duodenostomy with success. DISCUSSION Patients with “difficult to manage duodenum” usually present with hemodynamic instability with hostile abdomen. Complex procedures in an unstable patient are associated with adverse outcomes. In patients with significant comorbidities and instability the damage control principle of trauma surgery is gaining popularity. Tube duodenostomy technique described in this paper fits in well with that principle. CONCLUSION Application of tube duodenostomy instead of a complex procedure in an unstable patient provides an opportunity to stabilize the patient, converting an impending catastrophe to a future scheduled surgery. PMID:23357008

The single chest tube versus double chest tube application after pulmonary lobectomy: A systematic review and meta-analysis.

PubMed

Zhang, Xuefei; Lv, Desheng; Li, Mo; Sun, Ge; Liu, Changhong

2016-12-01

Draining of the chest cavity with two chest tubes after pulmonary lobectomy is a common practice. The objective of this study was to evaluate whether using two tubes after a pulmonary lobectomy is more effective than using a single tube. We performed a meta-analysis of five randomized studies that compared the single chest tube with double chest tube application after pulmonary lobectomy. The primary end-point was amount of drainage and duration of chest tube drainage. The secondary end-points were the patient's numbers of new drain insertion after operation, hospital stay after operation, the patient's numbers of subcutaneous emphysema after operation, the patient's numbers of residual pleural air space, pain score, the number of patients who need thoracentesis, and cost. Five randomized controlled trials totaling 502 patients were included. Meta-analysis results are as follows: There were statistically significant differences in amount of drainage (risk ratio [RR] = -0.15; 95% confidence interval [CI] = -3.17, -0.12, P = 0. 03), duration of chest tube drainage (RR = -0.43; 95% CI = -0.57, -0.19, P = 0.02), pain score (P < 0.05). Compared with patients receiving the double chest tube group, there were no statistically significant differences between the two groups with regard to the patient's numbers of new drain insertion after operation. Compared with the double chest tube, the single chest tube significantly decreases amount of drainage, duration of chest tube drainage, pain score, the number of patients who need thoracentesis, and cost. Although there is convincing evidence to confirm the results mentioned herein, they still need to be confirmed by large-sample, multicenter, randomized, controlled trials.

SiC/SiC Cladding Materials Properties Handbook

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

Snead, Mary A.; Katoh, Yutai; Koyanagi, Takaaki

When a new class of material is considered for a nuclear core structure, the in-pile performance is usually assessed based on multi-physics modeling in coordination with experiments. This report aims to provide data for the mechanical and physical properties and environmental resistance of silicon carbide (SiC) fiber–reinforced SiC matrix (SiC/SiC) composites for use in modeling for their application as accidenttolerant fuel cladding for light water reactors (LWRs). The properties are specific for tube geometry, although many properties can be predicted from planar specimen data. This report presents various properties, including mechanical properties, thermal properties, chemical stability under normal and offnormalmore » operation conditions, hermeticity, and irradiation resistance. Table S.1 summarizes those properties mainly for nuclear-grade SiC/SiC composites fabricated via chemical vapor infiltration (CVI). While most of the important properties are available, this work found that data for the in-pile hydrothermal corrosion resistance of SiC materials and for thermal properties of tube materials are lacking for evaluation of SiC-based cladding for LWR applications.« less

Method for producing micro heat panels

NASA Technical Reports Server (NTRS)

Camarda, Charles J. (Inventor); Peterson, George P. (Inventor); Rummler, Donald R. (Inventor)

1997-01-01

Flat or curved micro heat pipe panels are fabricated by arranging essentially parallel filaments in the shape of the desired panel. The configuration of the filaments corresponds to the desired configuration of the tubes that will constitute the heat pipes. A thermally conductive material is then deposited on and around the filaments to fill in the desired shape of the panel. The filaments are then removed, leaving tubular passageways of the desired configuration and surface texture in the material. The tubes are then filled with a working fluid and sealed. Composite micro heat pipe laminates are formed by layering individual micro heat pipe panels and bonding them to each other to form a single structure. The layering sequence of the micro heat pipe panels can be tailored to transport heat preferentially in specific directions as desired for a particular application.

78 FR 49232 - Airworthiness Directives; Learjet Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... tube is installed; and follow-on/corrective actions, as applicable. Since we issued that AD, we have... AD, and would require determining if a certain fuel crossflow tube is installed, performing repetitive measurements of the fuel crossflow tube and surrounding valves and cables, and doing corrective...

Micro-tube mass production device for microbial culture.

PubMed

Fujimoto, K; Ogawa, M; Higashi, K; Miki, N

2016-08-01

This paper describes mass production system of micro-tubes for microbial culture in an open environment. Microbes are used in many fields, such as food, medicine, environmental and energy. We proposed a microbe culture system using hydrogel micro-tubes, which can protect the target microbes inside from competitive microbes outside of the tubes while allow oxygen and nutrition to diffuse through. The hydrogel micro-tubes can be produced by a microfluidic device, which can precisely control the flow and therefore, the tube geometry. For practical applications of the micro-tube-based microbial culture, one of the biggest challenges is the scale-up of the micro-tube-based culture system, or mass production of the tubes. We developed a fluidic system that can produce multiple micro-tubes in parallel. We characterized the mass-produced micro channels and verified the effectiveness of the system.

Low Cost Cryocoolers for High Temperature Superconductor Communication Filters

NASA Technical Reports Server (NTRS)

Brown, Davina

1998-01-01

This final report describes the work performed by a consortium of Industry and Government to develop low cost cryocoolers. The specific application was for low cost commercial based high temperature superconductor communication filters. This program was initiated in January 1995 and resulted in the successful demonstration of an HTS filter dewar cooled by a low cost pulse tube cryocooler. Further development of this cryocooler technology is proceeding through various contracts underway and proposed at this time.

Effect of gravity opientation on the thermal performance of Stirling-type pulse tube cryocoolers

NASA Technical Reports Server (NTRS)

Ronald, Ross G., Jr.; Johnson, D. L.

2003-01-01

This paper extends the investigation of angular orientation effects to the refrigeration performance of high frequency (-40 Hz) Stirling-type pulse tube cryocoolers typical of those used in long-life space applications. Strong orientation effects on the performance of such cryocoolers have recently been observed during system-level testing of both linear and U-tube type pulse tubes. To quantify the angular dependency effects, data have been gathered on both U-tube and linear type pulse tubes of two different manufacturers as a function of orientation angle, cold-tip temperature, and compressor stroke.

Confined Assembly of Hollow Carbon Spheres in Carbonaceous Nanotube: A Spheres-in-Tube Carbon Nanostructure with Hierarchical Porosity for High-Performance Supercapacitor.

PubMed

Chen, Ze; Ye, Sunjie; Evans, Stephen D; Ge, Yuanhang; Zhu, Zhifeng; Tu, Yingfeng; Yang, Xiaoming

2018-05-01

Carbonaceous nanotubes (CTs) represent one of the most popular and effective carbon electrode materials for supercapacitors, but the electrochemistry performance of CTs is largely limited by their relatively low specific surface area, insufficient usage of intratube cavity, low content of heteroatom, and poor porosity. An emerging strategy for circumventing these issues is to design novel porous CT-based nanostructures. Herein, a spheres-in-tube nanostructure with hierarchical porosity is successfully engineered, by encapsulating heteroatom-doping hollow carbon spheres into one carbonaceous nanotube (HCSs@CT). This intriguing nanoarchitecture integrates the merits of large specific surface area, good porosity, and high content of heteroatoms, which synergistically facilitates the transportation and exchange of ions and electrons. Accordingly, the as-prepared HCSs@CTs possess outstanding performances as electrode materials of supercapacitors, including superior capacitance to that of CTs, HCSs, and their mixtures, coupled with excellent cycling life, demonstrating great potential for applications in energy storage. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low Dose MDCT with Tube Current Modulation: Role in Detection of Urolithiasis and Patient Effective Dose Reduction

PubMed Central

Kakkar, Chandan; Sripathi, Smiti; Parakh, Anushri; Shrivastav, Rajendra

2016-01-01

Introduction Urolithiasis is one of the major, recurring problem in young individuals and CT being the commonest diagnostic modality used. In order to reduce the radiation dose to the patient who are young and as stone formation is a recurring process; one of the simplest way would be, low dose CT along with tube current modulation. Aim Aim of this study was to compare the sensitivity and specificity of low dose (70mAs) with standard dose (250mAs) protocol in detecting urolithiasis and to define the tube current and mean effective patient dose by these protocols. Materials and Methods A prospective study was conducted in 200 patients over a period of 2 years with acute flank pain presentation. CT was performed in 100 cases with standard dose and another 100 with low dose protocol using tube current modulation. Sensitivity and specificity for calculus detection, percentage reduction of dose and tube current with low dose protocol was calculated. Results Urolithiasis was detected in 138 patients, 67 were examined by high dose and 71 were by low dose protocol. Sensitivity and Specificity of low dose protocol was 97.1% and 96.4% with similar results found in high BMI patients. Tube current modulation resulted in reduction of effective tube current by 12.17%. The mean effective patient dose for standard dose was 10.33 mSv whereas 2.92 mSv for low dose with 51.13–53.8% reduction in low dose protocol. Conclusion The study has reinforced that low-dose CT with tube current modulation is appropriate for diagnosis of urolithiasis with significant reduction in tube current and patient effective dose. PMID:27437322

Low Dose MDCT with Tube Current Modulation: Role in Detection of Urolithiasis and Patient Effective Dose Reduction.

PubMed

Koteshwar, Prakashini; Kakkar, Chandan; Sripathi, Smiti; Parakh, Anushri; Shrivastav, Rajendra

2016-05-01

Urolithiasis is one of the major, recurring problem in young individuals and CT being the commonest diagnostic modality used. In order to reduce the radiation dose to the patient who are young and as stone formation is a recurring process; one of the simplest way would be, low dose CT along with tube current modulation. Aim of this study was to compare the sensitivity and specificity of low dose (70mAs) with standard dose (250mAs) protocol in detecting urolithiasis and to define the tube current and mean effective patient dose by these protocols. A prospective study was conducted in 200 patients over a period of 2 years with acute flank pain presentation. CT was performed in 100 cases with standard dose and another 100 with low dose protocol using tube current modulation. Sensitivity and specificity for calculus detection, percentage reduction of dose and tube current with low dose protocol was calculated. Urolithiasis was detected in 138 patients, 67 were examined by high dose and 71 were by low dose protocol. Sensitivity and Specificity of low dose protocol was 97.1% and 96.4% with similar results found in high BMI patients. Tube current modulation resulted in reduction of effective tube current by 12.17%. The mean effective patient dose for standard dose was 10.33 mSv whereas 2.92 mSv for low dose with 51.13-53.8% reduction in low dose protocol. The study has reinforced that low-dose CT with tube current modulation is appropriate for diagnosis of urolithiasis with significant reduction in tube current and patient effective dose.

The gelatinous extracellular matrix facilitates transport studies in kelp: visualization of pressure-induced flow reversal across sieve plates

PubMed Central

Knoblauch, Jan; Peters, Winfried S.; Knoblauch, Michael

2016-01-01

Background and Aims In vascular plants, important questions regarding phloem function remain unanswered due to problems with invasive experimental procedures in this highly sensitive tissue. Certain brown algae (kelps; Laminariales) also possess sieve tubes for photoassimilate transport, but these are embedded in large volumes of a gelatinous extracellular matrix which isolates them from neighbouring cells. Therefore, we hypothesized that kelp sieve tubes might tolerate invasive experimentation better than their analogues in higher plants, and sought to establish Nereocystis luetkeana as an experimental system. Methods The predominant localization of cellulose and the gelatinous extracellular matrix in N. luetkeana was verified using specific fluorescent markers and confocal laser scanning microscopy. Sieve tubes in intact specimens were loaded with fluorescent dyes, either passively (carboxyfluorescein diacetate; CFDA) or by microinjection (rhodamine B), and the movement of the dyes was monitored by fluorescence microscopy. Key Results Application of CFDA demonstrated source to sink bulk flow in N. luetkeana sieve tubes, and revealed the complexity of sieve tube structure, with branches, junctions and lateral connections. Microinjection into sieve elements proved comparatively easy. Pulsed rhodamine B injection enabled the determination of flow velocity in individual sieve elements, and the direct visualization of pressure-induced reversals of flow direction across sieve plates. Conclusions The reversal of flow direction across sieve plates by pressurizing the downstream sieve element conclusively demonstrates that a critical requirement of the Münch theory is satisfied in kelp; no such evidence exists for tracheophytes. Because of the high tolerance of its sieve elements to experimental manipulation, N. luetkeana is a promising alternative to vascular plants for studying the fluid mechanics of sieve tube networks. PMID:26929203

The gelatinous extracellular matrix facilitates transport studies in kelp: visualization of pressure-induced flow reversal across sieve plates.

PubMed

Knoblauch, Jan; Peters, Winfried S; Knoblauch, Michael

2016-04-01

In vascular plants, important questions regarding phloem function remain unanswered due to problems with invasive experimental procedures in this highly sensitive tissue. Certain brown algae (kelps; Laminariales) also possess sieve tubes for photoassimilate transport, but these are embedded in large volumes of a gelatinous extracellular matrix which isolates them from neighbouring cells. Therefore, we hypothesized that kelp sieve tubes might tolerate invasive experimentation better than their analogues in higher plants, and sought to establish Nereocystis luetkeana as an experimental system. The predominant localization of cellulose and the gelatinous extracellular matrix in N. luetkeana was verified using specific fluorescent markers and confocal laser scanning microscopy. Sieve tubes in intact specimens were loaded with fluorescent dyes, either passively (carboxyfluorescein diacetate; CFDA) or by microinjection (rhodamine B), and the movement of the dyes was monitored by fluorescence microscopy. Application of CFDA demonstrated source to sink bulk flow in N. luetkeana sieve tubes, and revealed the complexity of sieve tube structure, with branches, junctions and lateral connections. Microinjection into sieve elements proved comparatively easy. Pulsed rhodamine B injection enabled the determination of flow velocity in individual sieve elements, and the direct visualization of pressure-induced reversals of flow direction across sieve plates. The reversal of flow direction across sieve plates by pressurizing the downstream sieve element conclusively demonstrates that a critical requirement of the Münch theory is satisfied in kelp; no such evidence exists for tracheophytes. Because of the high tolerance of its sieve elements to experimental manipulation, N. luetkeana is a promising alternative to vascular plants for studying the fluid mechanics of sieve tube networks. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Siphon flows in isolated magnetic flux tubes. IV - Critical flows with standing tube shocks

NASA Technical Reports Server (NTRS)

Thomas, John H.; Montesinos, Benjamin

1991-01-01

Critical siphon flows in arched, isolated magnetic flux tubes are studied within the thin flux tube approximation, with a view toward applications to intense magnetic flux concentrations in the solar photosphere. The results of calculations of the strength and position of the standing tube shock in the supercritical downstream branch of a critical siphon flow are presented, as are calculations of the flow variables all along the flux tube and the equilibrium path of the flux tube in the surrounding atmosphere. It is suggested that arched magnetic flux tubes, with magnetic field strength increased by a siphon flow, may be associated with some of the intense, discrete magnetic elements observed in the solar photosphere.

Template synthesis of test tube nanoparticles using non-destructive replication

PubMed Central

Wagner, Jonathan; Yao, Jingyuan; Rodgers, David; Hinds, Bruce

2013-01-01

Nano test tubes are a promising delivery vehicle for a range of therapeutics including small molecule drugs and biologics. However, current template synthesis methods of producing nano test tubes are prohibitively expensive and time consuming. Here, non-destructive template replication was used to increase nano test tube yield from porous alumina by more than a hundredfold. We demonstrate how to produce nano test tubes of several sizes and compositions including hybrid tubes with different inner and outer surfaces for targeted surface chemistry. Nano test tubes were readily suspended and stored in aqueous solutions without the need for chemical treatment. These nano test tubes should find application as delivery vehicles for therapeutics, particularly for processive “bionanoreactors” loaded with enzymes. PMID:23376956

Ordered transport and identification of particles

DOEpatents

Shera, E.B.

1993-05-11

A method and apparatus are provided for application of electrical field gradients to induce particle velocities to enable particle sequence and identification information to be obtained. Particle sequence is maintained by providing electroosmotic flow for an electrolytic solution in a particle transport tube. The transport tube and electrolytic solution are selected to provide an electroosmotic radius of >100 so that a plug flow profile is obtained for the electrolytic solution in the transport tube. Thus, particles are maintained in the same order in which they are introduced in the transport tube. When the particles also have known electrophoretic velocities, the field gradients introduce an electrophoretic velocity component onto the electroosmotic velocity. The time that the particles pass selected locations along the transport tube may then be detected and the electrophoretic velocity component calculated for particle identification. One particular application is the ordered transport and identification of labeled nucleotides sequentially cleaved from a strand of DNA.

Reflux condensation of pure vapors with and without a noncondensable gas inside plain and enhanced tubes

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

Abdelmessih, A.N.; Rabas, T.J.; Panchal, C.B.

1997-06-01

Estimates of the surface-area and vapor-release reductions are obtained when commercially available enhanced tubes (spirally ribbed) replace plain tubes in a reflux unit condensing pure organic vapors with different concentrations of a noncondensable gas. This investigation was undertaken because there are no existing data and/or prediction methods that are applicable for these shell-and-tube condensers commonly used in the process industries. To obtain these estimates, existing design methods published in the open literature were used. The major findings are that (1) surface-area reductions can almost approach the single-phase heat transfer enhancement level, and (2) vapor-release reductions can approach a factor ofmore » four. The important implication is that enhanced tubes appear to be very cost effective for addressing the recovery of volatile organic vapors (VOCs), and for a vast number of different reflux-condenser applications.« less

Ordered transport and identification of particles

DOEpatents

Shera, E. Brooks

1993-01-01

A method and apparatus are provided for application of electrical field gradients to induce particle velocities to enable particle sequence and identification information to be obtained. Particle sequence is maintained by providing electroosmotic flow for an electrolytic solution in a particle transport tube. The transport tube and electrolytic solution are selected to provide an electroosmotic radius of >100 so that a plug flow profile is obtained for the electrolytic solution in the transport tube. Thus, particles are maintained in the same order in which they are introduced in the transport tube. When the particles also have known electrophoretic velocities, the field gradients introduce an electrophoretic velocity component onto the electroosmotic velocity. The time that the particles pass selected locations along the transport tube may then be detected and the electrophoretic velocity component calculated for particle identification. One particular application is the ordered transport and identification of labeled nucleotides sequentially cleaved from a strand of DNA.

Automatic welding of stainless steel tubing

NASA Technical Reports Server (NTRS)

Clautice, W. E.

1978-01-01

The use of automatic welding for making girth welds in stainless steel tubing was investigated as well as the reduction in fabrication costs resulting from the elimination of radiographic inspection. Test methodology, materials, and techniques are discussed, and data sheets for individual tests are included. Process variables studied include welding amperes, revolutions per minute, and shielding gas flow. Strip chart recordings, as a definitive method of insuring weld quality, are studied. Test results, determined by both radiographic and visual inspection, are presented and indicate that once optimum welding procedures for specific sizes of tubing are established, and the welding machine operations are certified, then the automatic tube welding process produces good quality welds repeatedly, with a high degree of reliability. Revised specifications for welding tubing using the automatic process and weld visual inspection requirements at the Kennedy Space Center are enumerated.

Arc driver operation for either efficient energy transfer or high-current generator

NASA Technical Reports Server (NTRS)

Dannenberg, R. E.; Silva, A. F.

1972-01-01

An investigation is made to establish predictable electric arcs along triggered paths for research purposes, the intended application being the heating of the driver gas of a 1 MJ electrically driven shock tube. Trigger conductors consisting of wires, open tubes, and tubes pressurized with different gases were investigated either on the axis of the arc chamber or spiraled along the chamber walls. Design criteria are presented for successful arc initiation with reproducible voltage-current characteristics. Results are compared with other facilities and several application areas are discussed.

Application of nuclear analytical techniques using long-life sealed-tube neutron generators.

PubMed

Bach, P; Cluzeau, S; Lambermont, C

1994-01-01

The new range of sealed-tube neutron generators developed by SODERN appears to be appropriate for the industrial environment. The main characteristics are the high emission stability during the very long lifetime of the tube, flexible pulsed mode capability, safety in operation with no radiation in "off" state, and the easy transportation of equipment. Some applications of the neutron generators, called GENIE, are considered: high-sensitivity measurement of transuranic elements in nuclear waste drums, bulk material analysis for process control, and determination of the airborne pollutants for environmental monitoring.

Preliminary evaluation of a gel tube agglutination major cross-match method in dogs.

PubMed

Villarnovo, Dania; Burton, Shelley A; Horney, Barbara S; MacKenzie, Allan L; Vanderstichel, Raphaël

2016-09-01

A major cross-match gel tube test is available for use in dogs yet has not been clinically evaluated. This study compared cross-match results obtained using the gel tube and the standard tube methods for canine samples. Study 1 included 107 canine sample donor-recipient pairings cross-match tested with the RapidVet-H method gel tube test and compared results with the standard tube method. Additionally, 120 pairings using pooled sera containing anti-canine erythrocyte antibody at various concentrations were tested with leftover blood from a hospital population to assess sensitivity and specificity of the gel tube method in comparison with the standard method. The gel tube method had a good relative specificity of 96.1% in detecting lack of agglutination (compatibility) compared to the standard tube method. Agreement between the 2 methods was moderate. Nine of 107 pairings showed agglutination/incompatibility on either test, too few to allow reliable calculation of relative sensitivity. Fifty percent of the gel tube method results were difficult to interpret due to sample spreading in the reaction and/or negative control tubes. The RapidVet-H method agreed with the standard cross-match method on compatible samples, but detected incompatibility in some sample pairs that were compatible with the standard method. Evaluation using larger numbers of incompatible pairings is needed to assess diagnostic utility. The gel tube method results were difficult to categorize due to sample spreading. Weak agglutination reactions or other factors such as centrifuge model may be responsible. © 2016 American Society for Veterinary Clinical Pathology.

Gas sampling system for a mass spectrometer

DOEpatents

Taylor, Charles E; Ladner, Edward P

2003-12-30

The present invention relates generally to a gas sampling system, and specifically to a gas sampling system for transporting a hazardous process gas to a remotely located mass spectrometer. The gas sampling system includes a capillary tube having a predetermined capillary length and capillary diameter in communication with the supply of process gas and the mass spectrometer, a flexible tube surrounding and coaxial with the capillary tube intermediate the supply of process gas and the mass spectrometer, a heat transfer tube surrounding and coaxial with the capillary tube, and a heating device in communication the heat transfer tube for substantially preventing condensation of the process gas within the capillary tube.

Retortable Laminate/Polymeric Food Tubes for Specialized Feeding

DTIC Science & Technology

2012-06-01

on commercial off-the-shelf materials and not military unique. A market survey of commercially available laminated tubes revealed that they are all...on commercial off-the-shelf materials and not military unique. A market survey of commercially available laminated tubes revealed that they are...available materials and not be uniquely military. We surveyed the market for laminated retortable tubes and were not able to find any application

Levitating spherical particle in a slightly tapered tube at low Reynolds numbers: application to the low-flow rate rotameters.

PubMed

Champmartin, S; Ambari, A; Chhabra, R P

2012-12-01

In this study, a theoretical framework is developed to predict the equilibrium conditions of a non-neutrally buoyant sphere placed in a vertical conical tube as encountered in liquid rotameters. The analysis presented herein is applicable for a sphere heavier than the surrounding fluid, situated on the axis of a slightly tapered tube. The sphere is subject to the laminar flow conditions with the Reynolds numbers ranging between the Stokes type regimes up to values corresponding to slightly inertial regimes. In this work, we assume that the aperture angle of the tube is small and that the drag force is mainly due to the dissipation located in the gap between the tube and the sphere. Under these conditions, it is possible to consider the tube as locally cylindrical and we can use the results previously obtained for the correction factor of the Stokes force on a sphere subject to a Poiseuille flow in a tube of constant cross-section. We obtain an equation relating the flow rate to the vertical position of the sphere in the tube and the validity of this analysis is demonstrated by applying it to a commercially available rotameter. The present study provides a simple but sound theoretical method to calibrate such flowmeters.

Numerical analysis of inertance pulse tube cryocooler with a modified reservoir

NASA Astrophysics Data System (ADS)

Abraham, Derick; Damu, C.; Kuzhiveli, Biju T.

2017-12-01

Pulse tube cryocoolers are used for cooling applications, where very high reliability is required as in space applications. These cryocoolers require a buffer volume depending on the temperature to be maintained and cooling load. A miniature single stage coaxial Inertance Pulse Tube Cryocooler is proposed which operates at 80 K to provide a cooling effect of at least 2 W. In this paper a pulse tube cryocooler, with modified reservoir is suggested, where the reverse fluctuation in compressor case is used instead of a steady pressure in the reservoir to bring about the desired phase shift between the pressure and the mass flow rate in the cold heat exchanger. Therefore, the large reservoir of the cryocooler is replaced by the crank volume of the hermetically sealed linear compressor, and hence the cryocooler is simplified and compact in size. The components of the cryocooler consist of a connecting tube, aftercooler, regenerator, cold heat exchanger, flow straightener, pulse tube, warm heat exchanger, inertance tube and the modified reservoir along with the losses were designed and analyzed. Each part of the cryocooler was analysed using SAGE v11 and verified with ANSYS Fluent. The simulation results clearly show that there is 50% reduction in the reservoir volume for the modified Inertance pulse tube cryocooler.

Levitating spherical particle in a slightly tapered tube at low Reynolds numbers: Application to the low-flow rate rotameters

NASA Astrophysics Data System (ADS)

Champmartin, S.; Ambari, A.; Chhabra, R. P.

2012-12-01

In this study, a theoretical framework is developed to predict the equilibrium conditions of a non-neutrally buoyant sphere placed in a vertical conical tube as encountered in liquid rotameters. The analysis presented herein is applicable for a sphere heavier than the surrounding fluid, situated on the axis of a slightly tapered tube. The sphere is subject to the laminar flow conditions with the Reynolds numbers ranging between the Stokes type regimes up to values corresponding to slightly inertial regimes. In this work, we assume that the aperture angle of the tube is small and that the drag force is mainly due to the dissipation located in the gap between the tube and the sphere. Under these conditions, it is possible to consider the tube as locally cylindrical and we can use the results previously obtained for the correction factor of the Stokes force on a sphere subject to a Poiseuille flow in a tube of constant cross-section. We obtain an equation relating the flow rate to the vertical position of the sphere in the tube and the validity of this analysis is demonstrated by applying it to a commercially available rotameter. The present study provides a simple but sound theoretical method to calibrate such flowmeters.

Confined semiflexible polymers suppress fluctuations of soft membrane tubes.

PubMed

Mirzaeifard, Sina; Abel, Steven M

2016-02-14

We use Monte Carlo computer simulations to investigate tubular membrane structures with and without semiflexible polymers confined inside. At small values of membrane bending rigidity, empty fluid and non-fluid membrane tubes exhibit markedly different behavior, with fluid membranes adopting irregular, highly fluctuating shapes and non-fluid membranes maintaining extended tube-like structures. Fluid membranes, unlike non-fluid membranes, exhibit a local maximum in specific heat as their bending rigidity increases. The peak is coincident with a transition to extended tube-like structures. We further find that confining a semiflexible polymer within a fluid membrane tube reduces the specific heat of the membrane, which is a consequence of suppressed membrane shape fluctuations. Polymers with a sufficiently large persistence length can significantly deform the membrane tube, with long polymers leading to localized bulges in the membrane that accommodate regions in which the polymer forms loops. Analytical calculations of the energies of idealized polymer-membrane configurations provide additional insight into the formation of polymer-induced membrane deformations.

An update on Lab Rover: A hospital material transporter

NASA Technical Reports Server (NTRS)

Mattaboni, Paul

1994-01-01

The development of a hospital material transporter, 'Lab Rover', is described. Conventional material transport now utilizes people power, push carts, pneumatic tubes and tracked vehicles. Hospitals are faced with enormous pressure to reduce operating costs. Cyberotics, Inc. developed an Autonomous Intelligent Vehicle (AIV). This battery operated service robot was designed specifically for health care institutions. Applications for the AIV include distribution of clinical lab samples, pharmacy drugs, administrative records, x-ray distribution, meal tray delivery, and certain emergency room applications. The first AIV was installed at Lahey Clinic in Burlington, Mass. Lab Rover was beta tested for one year and has been 'on line' for an additional 2 years.

Outplanting long tubes with the expandable stinger: A new treatment for riparian restoration

Treesearch

David E. Steinfeld; Thomas D. Landis; Dan Culley

2002-01-01

Long tubes are a new stock type developed specifically for restoration of challenging sites such as disturbed riparian areas. Constructed out of polyvinyl chloride plastic pipe, long tubes have a Vexar lining to promote good root growth and easier extraction. The expandable stinger is a new invention that was developed to outplant long tubes. The stinger is attached to...

Confirming nasogastric tube placement: Is the colorimeter as sensitive and specific as X-ray? A diagnostic accuracy study.

PubMed

Mordiffi, Siti Zubaidah; Goh, Mien Li; Phua, Jason; Chan, Yiong-Huak

2016-09-01

The effect of delivering enteral nutrition or medications via a nasogastric tube that is inadvertently located in the tracheobronchial tract can cause respiratory complications. Although radiographic examination is accepted as the gold standard for confirming the position of patients' enteral tubes, it is costly, involves risks of radiation, and is not failsafe. Studies using carbon dioxide sensors to detect inadvertent nasogastric tube placements have been conducted in intensive care settings. However, none involved patients in general wards. The objective of this study was to ascertain the diagnostic measure of colorimeter, with radiographic examination as the reference standard, to confirm the location of nasogastric tubes in patients. A prospective observational study of a diagnostic test. This study was conducted in the general wards of an approximately 1100-bed acute care tertiary hospital of an Academic Medical Center in Singapore. Adult patients with nasogastric tubes admitted to the general wards were recruited into the study. The colorimeter was attached to the nasogastric tube to detect for the presence of carbon dioxide, suggestive of a tracheobronchial placement. The exact location of the nasogastric tube was subsequently confirmed by a radiographic examination. A total of 192 tests were undertaken. The colorimeter detected carbon dioxide in 29 tested nasogastric tubes, of which radiographic examination confirmed that four tubes were located in the tracheobronchial tract. The colorimeter failed to detect carbon dioxide in one nasogastric tube that was located in the tracheobronchial tract, thus, demonstrating a sensitivity of 0.80 [95% CI (0.376, 0.964)]. The colorimeter detected absence of carbon dioxide in 163 tested nasogastric tubes in which radiographic examination confirmed 160 gastrointestinal and one tracheobronchial placements, demonstrating a specificity of 0.865 [95% CI (0.808, 0.907)]. The colorimeter detected one tracheobronchial nasogastric tube placement that the radiographic examination was misinterpreted. The study found that the use of the colorimeter in the general ward setting was not 100% sensitive or specific in ascertaining the location of a nasogastric tube as previously reported by many studies undertaken in intensive care settings. This is the first study on the use of a colorimeter to confirm the placement of a nasogastric tube in adult patients in the general ward setting. More research on the use of a colorimeter in the general ward setting and its potential use in certain processes for confirming the placement of a nasogastric tube is warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

27 CFR 46.262 - Application.

Code of Federal Regulations, 2012 CFR

2012-04-01

... THE TREASURY (CONTINUED) TOBACCO MISCELLANEOUS REGULATIONS RELATING TO TOBACCO PRODUCTS AND CIGARETTE PAPERS AND TUBES Floor Stocks Tax on Certain Tobacco Products, Cigarette Papers, and Cigarette Tubes Held...

Social media networking: YouTube and search engine optimization.

PubMed

Jackson, Rem; Schneider, Andrew; Baum, Neil

2011-01-01

This is the third part of a three-part article on social media networking. This installment will focus on YouTube and search engine optimization. This article will explore the application of YouTube to the medical practice and how YouTube can help a practice retain its existing patients and attract new patients to the practice. The article will also describe the importance of search engine optimization and how to make your content appear on the first page of the search engines such as Google, Yahoo, and YouTube.

Utilization of recycled cathode ray tubes glass in cement mortar for X-ray radiation-shielding applications.

PubMed

Ling, Tung-Chai; Poon, Chi-Sun; Lam, Wai-Shung; Chan, Tai-Po; Fung, Karl Ka-Lok

2012-01-15

Recycled glass derived from cathode ray tubes (CRT) glass with a specific gravity of approximately 3.0 g/cm(3) can be potentially suitable to be used as fine aggregate for preparing cement mortars for X-ray radiation-shielding applications. In this work, the effects of using crushed glass derived from crushed CRT funnel glass (both acid washed and unwashed) and crushed ordinary beverage container glass at different replacement levels (0%, 25%, 50%, 75% and 100% by volume) of sand on the mechanical properties (strength and density) and radiation-shielding performance of the cement-sand mortars were studied. The results show that all the prepared mortars had compressive strength values greater than 30 MPa which are suitable for most building applications based on ASTM C 270. The density and shielding performance of the mortar prepared with ordinary crushed (lead-free) glass was similar to the control mortar. However, a significant enhancement of radiation-shielding was achieved when the CRT glasses were used due to the presence of lead in the glass. In addition, the radiation shielding contribution of CRT glasses was more pronounced when the mortar was subject to a higher level of X-ray energy. Copyright © 2011 Elsevier B.V. All rights reserved.

Health Instruction Packages: Specific Nursing Skills.

ERIC Educational Resources Information Center

Bates, Clarice; And Others

Text, illustrations, and exercises are utilized in a set of five learning modules designed to instruct nursing students in a variety of clinical skills. The first module, "Down the Tube: Insertion of a Nasogastric Tube" by Clarice Bates, describes materials and procedures used to insert a nasogastric tube through the nose and esophagus…

Preliminary design of a solar central receiver for a site-specific repowering application (Saguaro Power Plant). Volume IV. Appendixes. Final report, October 1982-September 1983

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

Weber, E.R.

1983-09-01

The appendixes for the Saguaro Power Plant includes the following: receiver configuration selection report; cooperating modes and transitions; failure modes analysis; control system analysis; computer codes and simulation models; procurement package scope descriptions; responsibility matrix; solar system flow diagram component purpose list; thermal storage component and system test plans; solar steam generator tube-to-tubesheet weld analysis; pipeline listing; management control schedule; and system list and definitions.

Working session 3: Tubing integrity

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

Cueto-Felgueroso, C.; Strosnider, J.

1997-02-01

Twenty-three individuals representing nine countries (Belgium, Canada, the Czech Republic, France, Japan, the Slovak Republic, Spain, the UK, and the US) participated in the session on tube integrity. These individuals represented utilities, vendors, consultants and regulatory authorities. The major subjects discussed by the group included overall objectives of managing steam generator tube degradation, necessary elements of a steam generator degradation management program, the concept of degradation specific management, structural integrity evaluations, leakage evaluations, and specific degradation mechanisms. The group`s discussions on these subjects, including conclusions and recommendations, are summarized in this article.

Contrastive Analysis and Research on Negative Pressure Beam Tube System and Positive Pressure Beam Tube System for Mine Use

NASA Astrophysics Data System (ADS)

Wang, Xinyi; Shen, Jialong; Liu, Xinbo

2018-01-01

Against the technical defects of universally applicable beam tube monitoring system at present, such as air suction in the beam tube, line clogging, long sampling time, etc., the paper analyzes the current situation of the spontaneous combustion fire disaster forecast of mine in our country and these defects one by one. On this basis, the paper proposes a research thought that improving the positive pressure beam tube so as to substitute the negative pressure beam tube. Then, the paper introduces the beam tube monitoring system based on positive pressure technology through theoretical analysis and experiment. In the comparison with negative pressure beam tube, the paper concludes the advantage of the new system and draws the conclusion that the positive pressure beam tube is superior to the negative pressure beam tube system both in test result and test time. At last, the paper proposes prospect of the beam tube monitoring system based on positive pressure technology.

A Calcium Sensor-Regulated Protein Kinase, CALCINEURIN B-LIKE PROTEIN-INTERACTING PROTEIN KINASE19, Is Required for Pollen Tube Growth and Polarity1[OPEN

PubMed Central

Zhou, Liming; Lan, Wenzhi; Chen, Binqing; Fang, Wei; Luan, Sheng

2015-01-01

Calcium plays an essential role in pollen tube tip growth. However, little is known concerning the molecular basis of the signaling pathways involved. Here, we identified Arabidopsis (Arabidopsis thaliana) CALCINEURIN B-LIKE PROTEIN-INTERACTING PROTEIN KINASE19 (CIPK19) as an important element to pollen tube growth through a functional survey for CIPK family members. The CIPK19 gene was specifically expressed in pollen grains and pollen tubes, and its overexpression induced severe loss of polarity in pollen tube growth. In the CIPK19 loss-of-function mutant, tube growth and polarity were significantly impaired, as demonstrated by both in vitro and in vivo pollen tube growth assays. Genetic analysis indicated that disruption of CIPK19 resulted in a male-specific transmission defect. Furthermore, loss of polarity induced by CIPK19 overexpression was associated with elevated cytosolic Ca2+ throughout the bulging tip, whereas LaCl3, a Ca2+ influx blocker, rescued CIPK19 overexpression-induced growth inhibition. Our results suggest that CIPK19 may be involved in maintaining Ca2+ homeostasis through its potential function in the modulation of Ca2+ influx. PMID:25713341

Endurance of Damping Properties of Foam-Filled Tubes

PubMed Central

Strano, Matteo; Marra, Alessandro; Mussi, Valerio; Goletti, Massimo; Bocher, Philippe

2015-01-01

The favorable energy-absorption properties of metal foams have been frequently proposed for damping or anti-crash applications. The aim of this paper is to investigate the endurance of these properties for composite structures, made by a metal or a hybrid metal-polymeric foam used as the core filling of a tubular metal case. The results of experimental tests are shown, run with two types of structures: 1) square steel tubes filled with aluminum or with hybrid aluminum-polymer foams; 2) round titanium tubes filled with aluminum foams. The paper shows that the damping properties of a foam-filled tube change (improve) with the number of cycles, while all other dynamic properties are nearly constant. This result is very important for several potential applications where damping is crucial, e.g., for machine tools. PMID:28793425

Endurance of Damping Properties of Foam-Filled Tubes.

PubMed

Strano, Matteo; Marra, Alessandro; Mussi, Valerio; Goletti, Massimo; Bocher, Philippe

2015-07-07

The favorable energy-absorption properties of metal foams have been frequently proposed for damping or anti-crash applications. The aim of this paper is to investigate the endurance of these properties for composite structures, made by a metal or a hybrid metal-polymeric foam used as the core filling of a tubular metal case. The results of experimental tests are shown, run with two types of structures: 1) square steel tubes filled with aluminum or with hybrid aluminum-polymer foams; 2) round titanium tubes filled with aluminum foams. The paper shows that the damping properties of a foam-filled tube change (improve) with the number of cycles, while all other dynamic properties are nearly constant. This result is very important for several potential applications where damping is crucial, e.g., for machine tools.

Auto-fusion and the shaping of neurons and tubes

PubMed Central

Soulavie, Fabien; Sundaram, Meera V.

2016-01-01

Cells adopt specific shapes that are necessary for specific functions. For example, some neurons extend elaborate arborized dendrites that can contact multiple targets. Epithelial and endothelial cells can form tiny seamless unicellular tubes with an intracellular lumen. Recent advances showed that cells can auto-fuse to acquire those specific shapes. During auto-fusion, a cell merges two parts of its own plasma membrane. In contrast to cell-cell fusion or macropinocytic fission, which result in the merging or formation of two separate membrane bound compartments, auto-fusion preserves one compartment, but changes its shape. The discovery of auto-fusion in C. elegans was enabled by identification of specific protein fusogens, EFF-1 and AFF-1, that mediate cell-cell fusion. Phenotypic characterization of eff-1 and aff-1 mutants revealed that fusogen-mediated fusion of two parts of the same cell can be used to sculpt dendritic arbors, reconnect two parts of an axon after injury, or form a hollow unicellular tube. Similar auto-fusion events recently were detected in vertebrate cells, suggesting that auto-fusion could be a widely used mechanism for shaping neurons and tubes. PMID:27436685

Boiling and condensation in microfin tubes

NASA Astrophysics Data System (ADS)

Schlager, Lynn M.

A general overview of microfin tubes and their applications is presented. Manufacturing processes, commercial availability, experimental heat transfer, and pressure drop data for various refrigerants (including alternative refrigerants and refrigerant-oil mixtures), physical mechanisms of enhancement, and the incorporation of microfin tubes in common heat exchanger configurations are discussed. Microfin tubes, also known by various trade names, are characterized by numerous small fins which typically spiral down the inside wall of tubes at angles ranging from 10 to 30 degrees. The number of fins ranges from 48 to 70 with typical fin heights of 0.12 to 0.30 mm (fin height generally less than 3 percent of the inside diameter of the tube). Fin shapes may vary and the inside surface area of microfin tubes is 10 to 70 percent greater than the area of equivalent smooth tubes. Heat transfer can be enhanced by up to a factor of three with microfin tubes.

Porous tube plant nutrient delivery system development: A device for nutrient delivery in microgravity

NASA Technical Reports Server (NTRS)

Dreschel, T. W.; Brown, C. S.; Piastuch, W. C.; Hinkle, C. R.; Knott, W. M.

1994-01-01

The Porous Tube Plant Nutrient Delivery Systems or PTPNDS (U.S. Patent #4,926,585) has been under development for the past six years with the goal of providing a means for culturing plants in microgravity, specifically providing water and nutrients to the roots. Direct applications of the PTPNDS include plant space biology investigations on the Space Shuttle and plant research for life support in the Space Station Freedom. In the past, we investigated various configurations, the suitability of different porous materials, and the effects of pressure and pore size on plant growth. Current work is focused on characterizing the physical operation of the system, examining the effects of solution aeration, and developing prototype configurations for the Plant Growth Unit (PGU), the flight system for the Shuttle mid-deck. Future developments will involve testing on KC-135 parabolic flights, the design of flight hardware and testing aboard the Space Shuttle.

Selection-driven evolution of sex-biased genes is consistent with sexual selection in Arabidopsis thaliana.

PubMed

Gossmann, Toni I; Schmid, Marc W; Grossniklaus, Ueli; Schmid, Karl J

2014-03-01

Sex-biased genes are genes with a preferential or specific expression in one sex and tend to show an accelerated rate of evolution in animals. Various hypotheses--which are not mutually exclusive--have been put forth to explain observed patterns of rapid evolution. One possible explanation is positive selection, but this has been shown only in few animal species and mostly for male-specific genes. Here, we present a large-scale study that investigates evolutionary patterns of sex-biased genes in the predominantly self-fertilizing plant Arabidopsis thaliana. Unlike most animal species, A. thaliana does not possess sex chromosomes, its flowers develop both male and female sexual organs, and it is characterized by low outcrossing rates. Using cell-specific gene expression data, we identified genes whose expression is enriched in comparison with all other tissues in the male and female gametes (sperm, egg, and central cell), as well as in synergids, pollen, and pollen tubes, which also play an important role in reproduction. Genes specifically expressed in gametes and synergids show higher rates of protein evolution compared with the genome-wide average and no evidence for positive selection. In contrast, pollen- and pollen tube-specific genes not only have lower rates of protein evolution but also exhibit a higher proportion of adaptive amino acid substitutions. We show that this is the result of increased levels of purifying and positive selection among genes with pollen- and pollen tube-specific expression. The increased proportion of adaptive substitutions cannot be explained by the fact that pollen- and pollen tube-expressed genes are enriched in segmental duplications, are on average older, or have a larger effective population size. Our observations are consistent with prezygotic sexual selection as a result of interactions during pollination and pollen tube growth such as pollen tube competition.

Crush analysis of the foam-filled bitubal circular tube under oblique impact

NASA Astrophysics Data System (ADS)

Djamaluddin, F.; Abdullah, S.; Arrifin, A. K.; Nopiah, Z. M.

2018-02-01

This paper presents crashworthiness analysis of bitubal cylindrical tubes under different impact angular. The numerical solution of double cylindrical tubes are determined by finite element analysis (FEA). Moreover, the structure was impacted by mass block as impactor respect to longitudinal direction of the tubes. The model of structure was developed by non-linear ABAQUS sofware with variations of load angle and dimensions of tube. The outcome of this study is the respons parameters such as the peak crusing force (PCF), energy absorption (EA) and specific energy absorption (SEA), thus it can be expected this tube as the great energy absorber.

YouTube Acceptance by University Educators and Students: A Cross-Cultural Perspective

ERIC Educational Resources Information Center

Jung, Insung; Lee, Yekyung

2015-01-01

Despite the huge popularity of YouTube, there has been little research into the factors affecting educational applications of this social medium. This study attempts to predict and compare factors influencing YouTube acceptance among university students and educators in two very different cultures, Japan and the USA, applying the Unified Theory of…

The Caenorhabditis elegans Excretory System: A Model for Tubulogenesis, Cell Fate Specification, and Plasticity

PubMed Central

Sundaram, Meera V.; Buechner, Matthew

2016-01-01

The excretory system of the nematode Caenorhabditis elegans is a superb model of tubular organogenesis involving a minimum of cells. The system consists of just three unicellular tubes (canal, duct, and pore), a secretory gland, and two associated neurons. Just as in more complex organs, cells of the excretory system must first adopt specific identities and then coordinate diverse processes to form tubes of appropriate topology, shape, connectivity, and physiological function. The unicellular topology of excretory tubes, their varied and sometimes complex shapes, and the dynamic reprogramming of cell identity and remodeling of tube connectivity that occur during larval development are particularly fascinating features of this organ. The physiological roles of the excretory system in osmoregulation and other aspects of the animal’s life cycle are only beginning to be explored. The cellular mechanisms and molecular pathways used to build and shape excretory tubes appear similar to those used in both unicellular and multicellular tubes in more complex organs, such as the vertebrate vascular system and kidney, making this simple organ system a useful model for understanding disease processes. PMID:27183565

Principles and application of shock-tubes and shock tunnels

NASA Technical Reports Server (NTRS)

Ried, R. C.; Clauss, H. G., Jr.

1963-01-01

The principles, theoretical flow equations, calculation techniques, limitations and practical performance characteristics of basic and high performance shock tubes and shock tunnels are presented. Selected operating curves are included.

Space Magnets Attracting Interest on Earth: Applications of Physical and Biological Techniques In the Study of Gravisensing and Response System of Plants

NASA Technical Reports Server (NTRS)

Hasenstein, Karl H.; Boody, April; Cox, David (Technical Monitor)

2002-01-01

The BioTube/Magnetic Field Apparatus (MFA) research is designed to provide insight into the organization and operation of the gravity sensing systems of plants and other small organisms. This experiment on STS-107 uses magnetic fields to manipulate sensory cells in plant roots, thus using magnetic fields as a tool to study gravity-related phenomena. The experiment will be located in the SPACEHAB module and is about the size of a household microwave oven. The goal of the experiment is to improve our understanding of the basic phenomenon of how plants respond to gravity. The BioTube/MFA experiment specifically examines how gravitational forces serve as a directional signal for growth in the low-gravity environment of space. As with all basic research, this study will contribute to an improved understanding of how plants grow and will have important implications for improving plant growth and productivity on Earth. In BioTube/MFA, magnetic fields will be used to determine whether the distribution of subcellular starch grains, called amyloplasts, within plant cells predicts the direction in which roots will grow and curve in microgravity.

Design and implementation of the ATLAS TRT front end electronics

NASA Astrophysics Data System (ADS)

Newcomer, Mitch; Atlas TRT Collaboration

2006-07-01

The ATLAS TRT subsystem is comprised of 380,000 4 mm straw tube sensors ranging in length from 30 to 80 cm. Polypropelene plastic layers between straws and a xenon-based gas mixture in the straws allow the straws to be used for both tracking and transition radiation detection. Detector-mounted electronics with data sparsification was chosen to minimize the cable plant inside the super-conducting solenoid of the ATLAS inner tracker. The "on detector" environment required a small footprint, low noise, low power and radiation-tolerant readout capable of triggering at rates up to 20 MHz with an analog signal dynamic range of >300 times the discriminator setting. For tracking, a position resolution better than 150 μm requires leading edge trigger timing with ˜1 ns precision and for transition radiation detection, a charge collection time long enough to integrate the direct and reflected signal from the unterminated straw tube is needed for position-independent energy measurement. These goals have been achieved employing two custom Application-specific integrated circuits (ASICS) and board design techniques that successfully separate analog and digital functionality while providing an integral part of the straw tube shielding.

Performance of a Miniature Pulse Tube Cryocooler

NASA Astrophysics Data System (ADS)

Matsumoto, N.; Yasukawa, Y.; Ohshima, K.; Minematsu, S.; Takeuchi, T.; Yoshizawa, K.; Matsushita, T.; Mizoguchi, Y.

2006-04-01

Fuji Electric Group has developed a miniature pulse tube cryocooler (PTC) of U-shaped configuration with a specific cooling capacity of 2W at 70K and requiring 100W of electrical input power. The emphasis has been on compactness, light weight, high performance, high reliability and low cost. This PTC is for commercial applications: for example, semiconductivity and high temperature superconductivity (HTS) devices used in wireless telecommunication systems and imaging sensors. The dimensions of the PTC have been reduced to 246mm wide by 232mm high and a weight of 8.5kg as integral configurations. The linear compressor motor uses two sets of moving coils to drive twin pistons supported by flexure bearings in a dual opposed configuration. The phase shifter, consisting of an inertance tube and reservoir tank, has been optimized. We produced and tested a prototype reduced-cost PTC. The prototype has a cooling capacity greater than 2.5W at 70K with 100W of electrical input power. The vibration of the cold head is less than 2 micrometers (peak to peak) when the hot-end side flange of the expander is fixed. This paper describes in detail its performance including inclination and vibration.

Enhanced Evaporation and Condensation in Tubes

NASA Astrophysics Data System (ADS)

Honda, Hiroshi

A state-of-the-art review of enhanced evaporation and condensation in horizontal microfin tubes and micro-channels that are used for air-conditioning and refrigeration applications is presented. The review covers the effects of flow pattern and geometrical parameters of the tubes on the heat transfer performance. Attention is paid to the effect of surface tension which leads to enhanced evaporation and condensation in the microfin tubes and micro-channels. A review of prior efforts to develop empirical correlations of the heat transfer coefficient and theoretical models for evaporation and condensation in the horizontal microfin tubes and micro-channels is also presented.

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

Xian, Y. B.; Xu, H. T.; Lu, X. P., E-mail: luxinpei@hotmail.com

In this work, for better applications of atmospheric pressure plasma jets, the physics of plasma streamers in a glass tube with a part of it covered by a conductor is investigated. To better understand the propagation mechanism of plasma bullets in capillary tubes passing through a curved or narrow passage for some biomedical or material applications, the propagation of plasma streamers in a tube covered by a floating conductor is investigated. For a plasma streamer propagating in a tube covered by a conductor, the plasma streamer is suppressed and becomes shorter, and a secondary streamer is generated in the tubemore » at the downstream end of the conductor. The larger the area covered by the conductor, or the thinner the tube, the stronger the plasma streamer is inhibited. The electric potential of the conductor is measured to be as high as 6 kV. On the other hand, a higher voltage applied on the HV electrode, or a higher gas flow rate will make the secondary plasma streamer longer. It is found that the capacitor formed by the conductor outside the tube and the wall of the tube plays an important role in inhibiting the original plasma streamer and generating the secondary streamer. Moreover, the active species generated by the original plasma play important role in generating a secondary plasma streamer.« less

Half-value-layer increase owing to tungsten buildup in the x-ray tube: fact or fiction.

PubMed

Stears, J G; Felmlee, J P; Gray, J E

1986-09-01

The half-value layer (HVL) of an x-ray beam is generally believed to increase with x-ray tube use. This increase in HVL has previously been attributed to the hardening of the x-ray beam as a result of a buildup of tungsten on the x-ray tube glass window. Radiographs and HVL measurements were obtained to determine the effect of tungsten deposited on the x-ray tube windows. This work, along with the HVL data from approximately 200 functioning x-ray tubes used for all applications that were monitored for more than 8 years, indicated there is no significant increase in HVL with diagnostic x-ray tube use.

Review of vortex tube expansion in vapour compression refrigeration system

NASA Astrophysics Data System (ADS)

Liu, Yefeng; Yu, Jun

2018-05-01

A vortex tube expansion device replacing the throttle valve is proposed to improve the efficiency of vapour compression refrigeration cycle by reducing the loss of irreversibility in expansion process. The vortex tube is well-suited for these applications because it is simple, compact, light, quiet. Thus, this paper presents an overview of the thermodynamic analysis of vapour compression refrigeration cycle with vortex tube expansion device using different refrigerants. The paper also reviews the experiments and the calculations presented in previous studies on temperature separation in the vortex tube. The temperature separation mechanism and the flow-field inside the vortex tubes is explored by measuring the pressure, velocity, and temperature fields.

Measurement of breakthrough volumes of volatile chemical warfare agents on a poly(2,6-diphenylphenylene oxide)-based adsorbent and application to thermal desorption-gas chromatography/mass spectrometric analysis.

PubMed

Kanamori-Kataoka, Mieko; Seto, Yasuo

2015-09-04

To establish adequate on-site solvent trapping of volatile chemical warfare agents (CWAs) from air samples, we measured the breakthrough volumes of CWAs on three adsorbent resins by an elution technique using direct electron ionization mass spectrometry. The trapping characteristics of Tenax(®) TA were better than those of Tenax(®) GR and Carboxen(®) 1016. The latter two adsorbents showed non-reproducible breakthrough behavior and low VX recovery. The specific breakthrough values were more than 44 (sarin) L/g Tenax(®) TA resin at 20°C. Logarithmic values of specific breakthrough volume for four nerve agents (sarin, soman, tabun, and VX) showed a nearly linear correlation with the reciprocals of their boiling points, but the data point of sulfur mustard deviated from this linear curve. Next, we developed a method to determine volatile CWAs in ambient air by thermal desorption-gas chromatography (TD-GC/MS). CWA solutions that were spiked into the Tenax TA(®) adsorbent tubes were analyzed by a two-stage TD-GC/MS using a Tenax(®) TA-packed cold trap tube. Linear calibration curves for CWAs retained in the resin tubes were obtained in the range between 0.2pL and 100pL for sarin, soman, tabun, cyclohexylsarin, and sulfur mustard; and between 2pL and 100pL for VX and Russian VX. We also examined the stability of CWAs in Tenax(®) TA tubes purged with either dry or 50% relative humidity air under storage conditions at room temperature or 4°C. More than 80% sarin, soman, tabun, cyclohexylsarin, and sulfur mustard were recovered from the tubes within 2 weeks. In contrast, the recoveries of VX and Russian VX drastically reduced with storage time at room temperature, resulting in a drop to 10-30% after 2 weeks. Moreover, we examined the trapping efficiency of Tenax TA(®) adsorbent tubes for vaporized CWA samples (100mL) prepared in a 500mL gas sampling cylinder. In the concentration range of 0.2-2.5mg/m(3), >50% of sarin, soman, tabun, cyclohexylsarin, and HD were recovered, whereas <1% of VX and Russian VX were recovered in the same concentration range. The results indicate that CWA vapors, with the exception of VX and Russian VX, can be measured by an on-site collection procedure using the Tenax(®) TA resin tubes, followed by a subsequent TD-GC/MS analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

30 CFR 7.25 - Critical characteristics.

Code of Federal Regulations, 2014 CFR

2014-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.25 Critical characteristics. A sample of each batch or lot of brattice cloth and ventilation tubing...

30 CFR 7.25 - Critical characteristics.

Code of Federal Regulations, 2011 CFR

2011-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.25 Critical characteristics. A sample of each batch or lot of brattice cloth and ventilation tubing...

30 CFR 7.25 - Critical characteristics.

Code of Federal Regulations, 2010 CFR

2010-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.25 Critical characteristics. A sample of each batch or lot of brattice cloth and ventilation tubing...

30 CFR 7.25 - Critical characteristics.

Code of Federal Regulations, 2012 CFR

2012-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.25 Critical characteristics. A sample of each batch or lot of brattice cloth and ventilation tubing...

30 CFR 7.25 - Critical characteristics.

Code of Federal Regulations, 2013 CFR

2013-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.25 Critical characteristics. A sample of each batch or lot of brattice cloth and ventilation tubing...

Growth dynamics and composition of tubular structures in a reaction-precipitation system

NASA Astrophysics Data System (ADS)

Pagano, Jason John

Self-organization in reaction precipitation systems occurs in many physical, chemical, biological, and geological systems. In particular, chemical reactions provide a wealth of examples for this intriguing process. Permanent tubular structures arise from the interplay of chemical and transport phenomena such as diffusion and fluid flow. These astonishing tubular structures are prevalent throughout nature. Examples include black smokers at hydrothermal vents, silica tubes in setting cement, soda-straw stalactites in caves, and biological structures such as the outer skeleton of certain algae. In this work, the aim is to establish and understand a laboratory scale model by examining the, seemingly simple, precipitation reaction between sodium silicate and copper sulfate as well as zinc sulfate. The tubular precipitation structures in so-called silica gardens are known to many scientists and non-scientists alike. However, little is known regarding their growth dynamics and chemical composition. We devised an injection technique which provides control over parameters that are not accessible in the classic silica garden system. For the example of cupric sulfate injection into waterglass solution, we identify three distinct growth regimes (jetting, popping, and budding) and study their concentration dependent transitions. Here we describe the composition and morphology of the tube material using techniques such as electron microscopy and vibrational spectroscopy. Specifically, we find that the tube wall consists of metal hydroxide that is stabilized by a thin, exterior silica layer. After synthesis the tubes can be further modified by using chemical and/or physical means. A second study aims to understand tubule formation under "reverse" conditions. More specifically, waterglass is being injected into lighter cupric sulfate solution. In these experiments, single, downward growing precipitation tubes are created. Four distinct growth regimes are observed and their stability in terms of flow rate and cupric sulfate concentration is investigated. Three of these growth regimes (reverse jetting, reverse popping, and reverse budding) resemble the same behavior for the injection of cupric sulfate into silicate solution. However, the reverse conditions studied herein reveal one novel regime in which the tube is limited by repetitive fracturing. The lengths of the broken-off tube segments and times between subsequent break-off events can be described by log-normal distributions. We also discuss the development of a method for synthesizing highly linear precipitation tubes via gas bubble injection and templating. In this method, an aqueous metal salt is injected into a large reservoir of waterglass. Systematic measurements show that the size of the bubble governs the tube radius. According to this radius, the system selects its growth velocity following volume conservation of the injected metal salt solution. Moreover, scanning electron microscopy reveals intricate ring patterns on the walls. We also show evidence for the existence of minimal and maximal tube radius. Lastly, we report the collapse of tubes at high concentrations of silicate solution, yielding twisted ribbon-like structures. Critical radii and tube collapse are discussed in terms of simple competing forces. Concluding, the latter study suggests that one can create interesting geometries and the possible production of speciality materials. Furthermore, we extend our results toward other metals. This study reveals that silica-supported zinc hydroxide walls can be reacted to form zinc oxide. The chemically activated walls are composed of zinc oxide nanoparticles that can be used for technical applications.

Tip-localized receptors control pollen tube growth and LURE sensing in Arabidopsis.

PubMed

Takeuchi, Hidenori; Higashiyama, Tetsuya

2016-03-10

Directional control of tip-growing cells is essential for proper tissue organization and cell-to-cell communication in animals and plants. In the sexual reproduction of flowering plants, the tip growth of the male gametophyte, the pollen tube, is precisely guided by female cues to achieve fertilization. Several female-secreted peptides have recently been identified as species-specific attractants that directly control the direction of pollen tube growth. However, the method by which pollen tubes precisely and promptly respond to the guidance signal from their own species is unknown. Here we show that tip-localized pollen-specific receptor-like kinase 6 (PRK6) with an extracellular leucine-rich repeat domain is an essential receptor for sensing of the LURE1 attractant peptide in Arabidopsis thaliana under semi-in-vivo conditions, and is important for ovule targeting in the pistil. PRK6 interacted with pollen-expressed ROPGEFs (Rho of plant guanine nucleotide-exchange factors), which are important for pollen tube growth through activation of the signalling switch Rho GTPase ROP1 (refs 7, 8). PRK6 conferred responsiveness to AtLURE1 in pollen tubes of the related species Capsella rubella. Furthermore, our genetic and physiological data suggest that PRK6 signalling through ROPGEFs and sensing of AtLURE1 are achieved in cooperation with the other PRK family receptors, PRK1, PRK3 and PRK8. Notably, the tip-focused PRK6 accumulated asymmetrically towards an external AtLURE1 source before reorientation of pollen tube tip growth. These results demonstrate that PRK6 acts as a key membrane receptor for external AtLURE1 attractants, and recruits the core tip-growth machinery, including ROP signalling proteins. This work provides insights into the orchestration of efficient pollen tube growth and species-specific pollen tube attraction by multiple receptors during male-female communication.

A vacuum tube vee-trough collector for solar heating and air conditioning applications

NASA Technical Reports Server (NTRS)

Selcuk, M. K.

1978-01-01

An analysis is conducted of the performance of a vee-trough vacuum tube collector proposed for use in solar heating and cooling applications. The vee-trough reflector is a triangular sectioned, flat surfaced reflector, whose axis is laid in the East-West direction. A vacuum tube receiver placed at the bottom of the vee-trough collects solar heat most efficiently since convection is completely eliminated. Radiation losses are reduced by use of selective coatings on the absorber. Owing to its high temperature capabilities (300-400 F), the proposed scheme could also be used for power generation applications in combination with an organic Rankine conversion system. It is especially recommended for unattended pumping stations since the reflectors only require reversal once every six months.

30 CFR 7.26 - Flame test apparatus.

Code of Federal Regulations, 2014 CFR

2014-07-01

... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.26 Flame... cloth and ventilation tubing shall be constructed as follows: (a) A 16-gauge stainless steel gallery...

30 CFR 7.26 - Flame test apparatus.

Code of Federal Regulations, 2013 CFR

2013-07-01

... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.26 Flame... cloth and ventilation tubing shall be constructed as follows: (a) A 16-gauge stainless steel gallery...

30 CFR 7.26 - Flame test apparatus.

Code of Federal Regulations, 2012 CFR

2012-07-01

... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.26 Flame... cloth and ventilation tubing shall be constructed as follows: (a) A 16-gauge stainless steel gallery...

Numerical simulation of a novel expanded metal tubular structure for crashworthiness application

NASA Astrophysics Data System (ADS)

Abdelaal, A. H. A.; Tarlochan, F.

2015-12-01

Search for new geometries and materials that would serve in crashworthiness applications is a cumulative process. Recent studies investigated the performance of expanded metal tubes and the possible ways to enhance its energy absorption capability. The aim of this work is to investigate the crashworthiness characteristics of new concept is proposed where expanded metal tube is suited into a double-walled tube made of the same material to form one structure. The tube was then numerically tested through a verified model using ABAQUS software. Moreover, the influence of the size of the expanded metal cell was also investigated in the present study. The new concept showed an enhanced energy absorption characteristics related to the change in the mass of the tubular structure. The enhancement was related to both the change in deformation pattern, and the increase in crushed mass.

A novel system for commissioning brachytherapy applicators: example of a ring applicator

NASA Astrophysics Data System (ADS)

Fonseca, Gabriel P.; Van den Bosch, Michiel R.; Voncken, Robert; Podesta, Mark; Verhaegen, Frank

2017-11-01

A novel system was developed to improve commissioning and quality assurance of brachytherapy applicators used in high dose rate (HDR). It employs an imaging panel to create reference images and to measure dwell times and dwell positions. As an example: two ring applicators of the same model were evaluated. An applicator was placed on the surface of an imaging panel and a HDR 192Ir source was positioned in an imaging channel above the panel to generate an image of the applicator, using the gamma photons of the brachytherapy source. The applicator projection image was overlaid with the images acquired by capturing the gamma photons emitted by the source dwelling inside the applicator. We verified 0.1, 0.2, 0.5 and 1.0 cm interdwell distances for different offsets, applicator inclinations and transfer tube curvatures. The data analysis was performed using in-house developed software capable of processing the data in real time, defining catheters and creating movies recording the irradiation procedure. One applicator showed up to 0.3 cm difference from the expected position for a specific dwell position. The problem appeared intermittently. The standard deviations of the remaining dwell positions (40 measurements) were less than 0.05 cm. The second ring applicator had a similar reproducibility with absolute coordinate differences from expected values ranging from  -0.10 up to 0.18 cm. The curvature of the transfer tube can lead to differences larger than 0.1 cm whilst the inclination of the applicator showed a negligible effect. The proposed method allows the verification of all steps of the irradiation, providing accurate information about dwell positions and dwell times. It allows the verification of small interdwell positions (⩽0.1 cm) and reduces measurement time. In addition, no additional radiation source is necessary since the HDR 192Ir source is used to generate an image of the applicator.

Hyperthermia in low aspect-ratio magnetic nanotubes for biomedical applications

NASA Astrophysics Data System (ADS)

Gutierrez-Guzman, D. F.; Lizardi, L. I.; Otálora, J. A.; Landeros, P.

2017-03-01

A simple model for the magnetization reversal process of low aspect-ratio ferromagnetic nanotubes (MNTs) is presented. Because of advantages over other geometries, these structures are interesting for biomedical applications, such as magnetic hyperthermia cancer therapy, where the heat released during magnetic reversal is used to destroy tumors. For example, the tubular geometry provides two independent functional surfaces that may be selectively manipulated and also gives a storage cavity. Owing to their large surface to weight ratio and low mass density, MNTs are not decanted by gravity. We calculated magnetic phase diagrams, energy barriers, nucleation fields, and the amount of dissipated heat and specific absorption rate for magnetite nanotubes. The geometrical parameters were varied, and simple formulae were used to optimize the tube response under alternating excitation, as required for magnetic hyperthermia applications.

Metal glass vacuum tube solar collectors are approaching lower-medium temperature heat application.

PubMed

Jiang, Xinian

2010-04-26

Solar thermal collectors are widely used worldwide mainly for hot water preparation at a low temperature (less than 80?C). Applications including many industrial processes and central air conditioning with absorption chillers, instead require lower-medium temperature heat (between 90 degrees C and 150 degrees C) to be driven when using solar thermal energy. The metal absorber glass vacuum tube collectors (MGVT) are developed for this type of applications. Current state-of-art and possible future technology development of MGVT are presented.

Beam hardening and partial beam hardening of the bowtie filter: Effects on dosimetric applications in CT

NASA Astrophysics Data System (ADS)

Lopez-Rendon, X.; Zhang, G.; Bosmans, H.; Oyen, R.; Zanca, F.

2014-03-01

Purpose: To estimate the consequences on dosimetric applications when a CT bowtie filter is modeled by means of full beam hardening versus partial beam hardening. Method: A model of source and filtration for a CT scanner as developed by Turner et. al. [1] was implemented. Specific exposures were measured with the stationary CT X-ray tube in order to assess the equivalent thickness of Al of the bowtie filter as a function of the fan angle. Using these thicknesses, the primary beam attenuation factors were calculated from the energy dependent photon mass attenuation coefficients and used to include beam hardening in the spectrum. This was compared to a potentially less computationally intensive approach, which accounts only partially for beam hardening, by giving the photon spectrum a global (energy independent) fan angle specific weighting factor. Percentage differences between the two methods were quantified by calculating the dose in air after passing several water equivalent thicknesses representative for patients having different BMI. Specifically, the maximum water equivalent thickness of the lateral and anterior-posterior dimension and of the corresponding (half) effective diameter were assessed. Results: The largest percentage differences were found for the thickest part of the bowtie filter and they increased with patient size. For a normal size patient they ranged from 5.5% at half effective diameter to 16.1% for the lateral dimension; for the most obese patient they ranged from 7.7% to 19.3%, respectively. For a complete simulation of one rotation of the x-ray tube, the proposed method was 12% faster than the complete simulation of the bowtie filter. Conclusion: The need for simulating the beam hardening of the bow tie filter in Monte Carlo platforms for CT dosimetry will depend on the required accuracy.

Proceedings of the International Cryocooler Conference (7th) Held in Santa Fe, New Mexico on 17-19 November 1992. Part 4

DTIC Science & Technology

1993-04-01

and Long Life Applications, Stirling Cryocoolers , Pulse Tube Refrigerators, Novel Concepts and Component D)evclopment, Low Temperature Regenerator... Stirling Cryocoolers , Pulse Tube Refrigerators, Novel Concepts and Component Development, Low Temperature Regenerator Development, and J-T and...213 LINEARIZED PULSE TUBE CRYOCOOLER THEORY ....H . M ilels .. .... ...................... ..... ...... ....... ......... 22 1

Air Force Technical Objective Document, FY89.

DTIC Science & Technology

1988-04-01

threat warning; multimegawatt stand-off jammers; a family of new, broadband , active decoy expendables; E4? subsystems and EW suites for Military...and monolithic integrated circuits. (3) Microwave TWTs Develop microwave tube technology and selected thermionic power sources and amplifiers for ECM...Improved design reliability and multiple application of tube technology are stressed. Improve Traveling Wave Tube ( TWT ) reliability by instrumenting a TWT

Glove box for water pit applications

DOEpatents

Mills, William C [Richland, WA; Rabe, Richard A [North Fork, ID

2005-01-18

A glove box assembly that includes a glove box enclosure attached to a longitudinally extending hollow tube having an entranceway, wherein the portion of the tube is in a liquid environment. An elevator member is provided for raising an object that is introduced into the hollow tube from the liquid environment to a gas environment inside the glove box enclosure while maintaining total containment.

Parsimonious evaluation of concentric-tube continuum robot equilibrium conformation.

PubMed

Rucker, Daniel Caleb; Webster Iii, Robert J

2009-09-01

Dexterous at small diameters, continuum robots consisting of precurved concentric tubes are well-suited for minimally invasive surgery. These active cannulas are actuated by relative translations and rotations applied at the tube bases, which create bending via elastic tube interaction. An accurate kinematic model of cannula shape is required for applications in surgical and other settings. Previous models are limited to circular tube precurvatures, and neglect torsional deformation in curved sections. Recent generalizations account for arbitrary tube preshaping and bending and torsion throughout the cannula, providing differential equations that define cannula shape. In this paper, we show how to simplify these equations using Frenet-Serret frames. An advantage of this approach is the interpretation of torsional components of the preset tube shapes as "forcing functions" on the cannula's differential equations. We also elucidate a process for numerically solving the differential equations, and use it to produce simulations illustrating the implications of torsional deformation and helical tube shapes.

Characterization of mechanical properties of hydroxyapatite-silicon-multi walled carbon nano tubes composite coatings synthesized by EPD on NiTi alloys for biomedical application.

PubMed

Khalili, Vida; Khalil-Allafi, Jafar; Sengstock, Christina; Motemani, Yahya; Paulsen, Alexander; Frenzel, Jan; Eggeler, Gunther; Köller, Manfred

2016-06-01

Release of Ni(1+) ions from NiTi alloy into tissue environment, biological response on the surface of NiTi and the allergic reaction of atopic people towards Ni are challengeable issues for biomedical application. In this study, composite coatings of hydroxyapatite-silicon multi walled carbon nano-tubes with 20wt% Silicon and 1wt% multi walled carbon nano-tubes of HA were deposited on a NiTi substrate using electrophoretic methods. The SEM images of coated samples exhibit a continuous and compact morphology for hydroxyapatite-silicon and hydroxyapatite-silicon-multi walled carbon nano-tubes coatings. Nano-indentation analysis on different locations of coatings represents the highest elastic modulus (45.8GPa) for HA-Si-MWCNTs which is between the elastic modulus of NiTi substrate (66.5GPa) and bone tissue (≈30GPa). This results in decrease of stress gradient on coating-substrate-bone interfaces during performance. The results of nano-scratch analysis show the highest critical distance of delamination (2.5mm) and normal load before failure (837mN) as well as highest critical contact pressure for hydroxyapatite-silicon-multi walled carbon nano-tubes coating. The cell culture results show that human mesenchymal stem cells are able to adhere and proliferate on the pure hydroxyapatite and composite coatings. The presence of both silicon and multi walled carbon nano-tubes (CS3) in the hydroxyapatite coating induce more adherence of viable human mesenchymal stem cells in contrast to the HA coated samples with only silicon (CS2). These results make hydroxyapatite-silicon-multi walled carbon nano-tubes a promising composite coating for future bone implant application. Copyright © 2016 Elsevier Ltd. All rights reserved.

m-YouTube Mobile UI: Video Selection Based on Social Influence

NASA Astrophysics Data System (ADS)

Marcus, Aaron; Perez, Angel

The ease-of-use of Web-based video-publishing services provided by applications like YouTube has encouraged a new means of asynchronous communication, in which users can post videos not only to make them public for review and criticism, but also as a way to express moods, feelings, or intentions to an ever-growing network of friends. Following the current trend of porting Web applications onto mobile platforms, the authors sought to explore user-interface design issues of a mobile-device-based YouTube, which they call m-YouTube. They first analyzed the elements of success of the current YouTube Web site and observed its functionality. Then, they looked for unsolved issues that could give benefit through information-visualization design for small screens on mobile phones to explore a mobile version of such a product/service. The biggest challenge was to reduce the number of functions and amount information to fit into a mobile phone screen, but still be usable, useful, and appealing within the YouTube context of use and user experience. Borrowing ideas from social research in the area of social influence processes, they made design decisions aiming to help YouTube users to make the decision of what video content to watch and to increase the chances of YouTube authors being evaluated and observed by peers. The paper proposes a means to visualize large amounts of video relevant to YouTube users by using their friendship network as a relevance indicator to help in the decision-making process.

Application of a stepwise method for analyzing fouling in shell-and-tube exchangers

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

Prieto, M.M.; Miranda, J.; Sigales, B.

1999-12-01

This article presents the results of the application of a quite simple method for analyzing shell-side fouling in shell-and-tube exchangers, capable of taking into account the formation or irregular fouling deposits with variable thermal conductivity. This method, based on the utilization of elementary heat exchangers, has been implemented for E-shell TEMA-type heat exchangers with two tube passes. Several fouling deposit distributions have been simulated so as to ascertain their effects on the heat transfer rate. These distributions consider that fouling is concentrated in zones where the temperature of the fluids is maximum or minimum.

Myogenic specification in somites: induction by axial structures.

PubMed

Buffinger, N; Stockdale, F E

1994-06-01

Specification of the myogenic phenotype in somites was examined in the early chick embryo using organotypic explant cultures stained with monoclonal antibodies to myosin heavy chain. It was found that myogenic specification (formation of muscle fibers in explants of somites or segmental plates cultured alone) does not occur until Hamburger and Hamilton stage 11 (12-14 somites). At this stage, only the somites in the rostral half of the embryo are myogenically specified. By Hamburger and Hamilton stage 12 (15-17 somites), the three most caudal somites were not specified to be myogenic while most or all of the more rostral somites are specified to myogenesis. Somites from older embryos (stage 13-15, 18-26 somites) showed the same pattern of myogenic specification--all but the three most caudal somites were specified. We investigated the effects of the axial structures, the notochord and neural tube, on myogenic specification. Both the notochord and neural tube were able to induce myogenesis in unspecified somites. In contrast, the neural tube, but not the notochord, was able to induce myogenesis in explants of segmental plate, a structure which is not myogenic when cultured alone. When explants of specified somites were stained with antibodies to slow or fast MyHC, it was found that myofiber diversity (fast and fast slow fibers) was established very early in development (as early as Hamburger and Hamilton stage 11). We also found fiber diversity in explants of unspecified somites (the three most caudal somites from stage 11 to 15) when they were recombined with notochord or neural tube. We conclude that myogenic specification in the embryo results in diverse fiber types and is an inductive process which is mediated by factors produced by the neural tube and notochord.

Evaluation of a new single-tube multiprobe real-time PCR for diagnosis of Entamoeba histolytica and Entamoeba dispar.

PubMed

Liang, Shih-Yu; Hsia, Kan-Tai; Chan, Yun-Hsien; Fan, Chia-Kwung; Jiang, Donald Dah-Shyong; Landt, Olfert; Ji, Dar-Der

2010-08-01

A single-tube multiprobe real-time PCR assay for simultaneous detection of Entamoeba histolytica and Entamoeba dispar was developed. One primer pair with 2 species-specific probes was designed based on new SSU RNA regions of the ribosomal DNA-containing episome. The sensitivity is 1 parasite per milliliter of feces and thus superior to the conventional nested PCR and comparable to other published real-time PCR protocols. The applicability for clinical diagnosis was validated with 218 stool specimens from patients. A total of 51 E. histolytica and 39 E. dispar positive samples was detected by the multiprobe real-time PCR compared to 39 and 22 by routine nested PCR diagnosis. The detection rate of Entamoeba species for the multiprobe real-time PCR assays was significantly higher than the nested PCR (40.8% vs. 28.0%, P < 0.01). The test did not show cross reactivity with DNA from Entamoeba moshkovskii, Giardia lamblia , Cryptosporidium sp., Escherichia coli , or other nonpathogenic enteric parasites. The multiprobe real-time PCR assay is simple and rapid and has high specificity and sensitivity. The assay could streamline the laboratory diagnosis procedure and facilitate epidemiological investigation.

On guided circumferential waves in soft electroactive tubes under radially inhomogeneous biasing fields

NASA Astrophysics Data System (ADS)

Wu, Bin; Su, Yipin; Chen, Weiqiu; Zhang, Chuanzeng

2017-02-01

Soft electroactive (EA) tube actuators and many other cylindrical devices have been proposed recently in literature, which show great advantages over those made from conventional hard solid materials. However, their practical applications may be limited because these soft EA devices are prone to various failure modes. In this paper, we present an analysis of the guided circumferential elastic waves in soft EA tube actuators, which has potential applications in the in-situ nondestructive evaluation (NDE) or online structural health monitoring (SHM) to detect structural defects or fatigue cracks in soft EA tube actuators and in the self-sensing of soft EA tube actuators based on the concept of guided circumferential elastic waves. Both circumferential SH and Lamb-type waves in an incompressible soft EA cylindrical tube under inhomogeneous biasing fields are considered. The biasing fields, induced by the application of an electric voltage difference to the electrodes on the inner and outer cylindrical surfaces of the EA tube in addition to an axial pre-stretch, are inhomogeneous in the radial direction. Dorfmann and Ogden's theory of nonlinear electroelasticity and the associated linear theory for small incremental motion constitute the basis of our analysis. By means of the state-space formalism for the incremental wave motion along with the approximate laminate technique, dispersion relations are derived in a particularly efficient way. For a neo-Hookean ideal dielectric model, the proposed approach is first validated numerically. Numerical examples are then given to show that the guided circumferential wave propagation characteristics are significantly affected by the inhomogeneous biasing fields and the geometrical parameters. Some particular phenomena such as the frequency veering and the nonlinear dependence of the phase velocity on the radial electric voltage are discussed. Our numerical findings demonstrate that it is feasible to use guided circumferential elastic waves for the ultrasonic non-destructive online SHM to detect interior structural defects or fatigue cracks and for the self-sensing of the actual state of the soft EA tube actuator.

Space power thermal management materials and fabrication technologies for commerical use

NASA Astrophysics Data System (ADS)

Rosenfeld, John H.; Anderson, William G.; Horner-Richardson, Kevin; Hartenstine, John R.; Keller, Robert F.; Beals, James T.

1995-01-01

This paper describes three materials technologies, developed for space nuclear power thermal management, with exciting and varied applications in other fields. Six dual-use applications are presented. The three basic technologies are described: (1) Refractory-metal/ceramic layered composites can be made into thin, rigid, vacuum tight shells. These shells can be tailored for excellent impact resistance and/or excellent corrision/erosion properties. Dual use applications range from micrometeroid shield radiators for spacecraft to erosion resistant waste-stream heat recovery for corrosive exhaust. (2.) Porous metal technology was initially developed to produce wicks for liquid metal heat pipes. This technology is being developed in several new directions. Porous metal heat exchangers feature extraordinarily high specific surface ratios and have absorbed heat fluxes in excess of 100 MW/m2. Porous metal structures are highly compliant, so the technology has been expanded to produce a compliant interface for the attachment of materials with widely different coefficients of thermal expansion such as low expansion carbon-carbon to high expansion metals. (3.) The paper also describes a process, developed for space nuclear power (thermionics), which achieves 100% dense tungsten by plasma spraying. This could have major application in the reprocessing of spent nuclear fuel or other pyrochemical processes, where it would replace gun-drilled tungsten-molybdenum tubes with pure tungsten tubes of smaller diameter, longer, and thiner walled. The process could produce pure tungsten components in complex shapes for arcjet thrusters and other electric propulsion devices.

Artificial sensory organs: latest progress.

PubMed

Nakamura, Tatsuo; Inada, Yuji; Shigeno, Keiji

2018-03-01

This study introduces the latest progress on the study of artificial sensory organs, with a special emphasis on the clinical results of artificial nerves and the concept of in situ tissue engineering. Peripheral nerves have a strong potential for regeneration. An artificial nerve uses this potential to recover a damaged peripheral nerve. The polyglycolic acid collagen tube (PGA-C tube) is a bio-absorbable tube stuffed with collagen of multi-chamber structure that consists of thin collagen films. The clinical application of the PGA-C tube began in 2002 in Japan. The number of PGA-C tubes used is now beyond 300, and satisfactory results have been reported on peripheral nerve repairs. This PGA-C tube is also effective for patients suffering from neuropathic pain.

Heat transfer simulation of unsteady swirling flow in a vortex tube

NASA Astrophysics Data System (ADS)

Veretennikov, S. V.; Piralishvili, Sh A.; Evdokimov, O. A.; Guryanov, A. I.

2018-03-01

Effectiveness of not-adiabatic vortex tube application in the cooling systems of gas turbine blades depends on characteristics of swirling flows formed in the energy separation chamber. An analysis of the flow structure in the vortex tube channels has shown a presence of a complex three-dimensional spiral vortex, formed under relatively high turbulence intensity and vortex core precession. This indicates the presence of a significant unsteady flow in the energy separation chamber of the vortex tube that has a great influence on convective heat transfer of the swirling flow to the inner surface of tube. The paper contains the results of investigation of gas dynamics and heat transfer in the vortex tube taking into account the flow unsteadiness.

Gas Flow Detection System

NASA Technical Reports Server (NTRS)

Moss, Thomas; Ihlefeld, Curtis; Slack, Barry

2010-01-01

This system provides a portable means to detect gas flow through a thin-walled tube without breaking into the tubing system. The flow detection system was specifically designed to detect flow through two parallel branches of a manifold with only one inlet and outlet, and is a means for verifying a space shuttle program requirement that saves time and reduces the risk of flight hardware damage compared to the current means of requirement verification. The prototype Purge Vent and Drain Window Cavity Conditioning System (PVD WCCS) Flow Detection System consists of a heater and a temperature-sensing thermistor attached to a piece of Velcro to be attached to each branch of a WCCS manifold for the duration of the requirement verification test. The heaters and thermistors are connected to a shielded cable and then to an electronics enclosure, which contains the power supplies, relays, and circuit board to provide power, signal conditioning, and control. The electronics enclosure is then connected to a commercial data acquisition box to provide analog to digital conversion as well as digital control. This data acquisition box is then connected to a commercial laptop running a custom application created using National Instruments LabVIEW. The operation of the PVD WCCS Flow Detection System consists of first attaching a heater/thermistor assembly to each of the two branches of one manifold while there is no flow through the manifold. Next, the software application running on the laptop is used to turn on the heaters and to monitor the manifold branch temperatures. When the system has reached thermal equilibrium, the software application s graphical user interface (GUI) will indicate that the branch temperatures are stable. The operator can then physically open the flow control valve to initiate the test flow of gaseous nitrogen (GN2) through the manifold. Next, the software user interface will be monitored for stable temperature indications when the system is again at thermal equilibrium with the test flow of GN2. The temperature drop of each branch from its "no flow" stable temperature peak to its stable "with flow" temperature will allow the operator to determine whether a minimum level of flow exists. An alternative operation has the operator turning on the software only long enough to record the ambient temperature of the tubing before turning on the heaters and initiating GN2 flow. The stable temperature of the heated tubing with GN2 flow is then compared with the ambient tubing temperature to determine if flow is present in each branch. To help quantify the level of flow in the manifolds, each branch will be bench calibrated to establish its thermal properties using the flow detection system and different flow rates. These calibration values can then be incorporated into the software application to provide more detailed flow rate information.

Pressurized security barrier and alarm system

DOEpatents

Carver, Don W.

1995-01-01

A security barrier for placement across a passageway is made up of interconnected pressurized tubing made up in a grid pattern with openings too small to allow passage. The tubing is connected to a pressure switch, located away from the barrier site, which activates an alarm upon occurrence of a pressure drop. A reinforcing bar is located inside and along the length of the tubing so as to cause the tubing to rupture and set off the alarm upon an intruder's making an attempt to crimp and seal off a portion of the tubing by application of a hydraulic tool. Radial and rectangular grid patterns are disclosed.

Pressurized security barrier and alarm system

DOEpatents

Carver, D.W.

1995-04-11

A security barrier for placement across a passageway is made up of interconnected pressurized tubing made up in a grid pattern with openings too small to allow passage. The tubing is connected to a pressure switch, located away from the barrier site, which activates an alarm upon occurrence of a pressure drop. A reinforcing bar is located inside and along the length of the tubing so as to cause the tubing to rupture and set off the alarm upon an intruder`s making an attempt to crimp and seal off a portion of the tubing by application of a hydraulic tool. Radial and rectangular grid patterns are disclosed. 7 figures.

Thermodynamic properties of the S =1 /2 twisted triangular spin tube

NASA Astrophysics Data System (ADS)

Ito, Takuya; Iino, Chihiro; Shibata, Naokazu

2018-05-01

Thermodynamic properties of the twisted three-leg spin tube under magnetic field are studied by the finite-T density-matrix renormalization group method. The specific heat, spin, and chiral susceptibilities of the infinite system are calculated for both the original and its low-energy effective models. The obtained results show that the presence of the chirality is observed as a clear peak in the specific heat at low temperature and the contribution of the chirality dominates the low-temperature part of the specific heat as the exchange coupling along the spin tube decreases. The peak structures in the specific heat, spin, and chiral susceptibilities are strongly modified near the quantum phase transition where the critical behaviors of the spin and chirality correlations change. These results confirm that the chirality plays a major role in characteristic low-energy behaviors of the frustrated spin systems.

46 CFR 56.01-2 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

...”), 56.10-5; 56.60-1; (4) ASTM A 106-95, Standard Specification for Seamless Carbon Steel Pipe for High...), Standard Specification for Seamless Carbon Steel Boiler Tubes for High-Pressure Service (“ASTM A 192”), 56... Steel Boiler and Superheater Tubes for High-Pressure Service (“ASTM A 226”), 56.60-1; (19) ASTM A 234/A...

46 CFR 56.01-2 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

...”), 56.10-5; 56.60-1; (4) ASTM A 106-95, Standard Specification for Seamless Carbon Steel Pipe for High...), Standard Specification for Seamless Carbon Steel Boiler Tubes for High-Pressure Service (“ASTM A 192”), 56... Steel Boiler and Superheater Tubes for High-Pressure Service (“ASTM A 226”), 56.60-1; (19) ASTM A 234/A...

Auto-fusion and the shaping of neurons and tubes.

PubMed

Soulavie, Fabien; Sundaram, Meera V

2016-12-01

Cells adopt specific shapes that are necessary for specific functions. For example, some neurons extend elaborate arborized dendrites that can contact multiple targets. Epithelial and endothelial cells can form tiny seamless unicellular tubes with an intracellular lumen. Recent advances showed that cells can auto-fuse to acquire those specific shapes. During auto-fusion, a cell merges two parts of its own plasma membrane. In contrast to cell-cell fusion or macropinocytic fission, which result in the merging or formation of two separate membrane bound compartments, auto-fusion preserves one compartment, but changes its shape. The discovery of auto-fusion in C. elegans was enabled by identification of specific protein fusogens, EFF-1 and AFF-1, that mediate cell-cell fusion. Phenotypic characterization of eff-1 and aff-1 mutants revealed that fusogen-mediated fusion of two parts of the same cell can be used to sculpt dendritic arbors, reconnect two parts of an axon after injury, or form a hollow unicellular tube. Similar auto-fusion events recently were detected in vertebrate cells, suggesting that auto-fusion could be a widely used mechanism for shaping neurons and tubes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Convective heat transfer in foams under laminar flow in pipes and tube bundles.

PubMed

Attia, Joseph A; McKinley, Ian M; Moreno-Magana, David; Pilon, Laurent

2012-12-01

The present study reports experimental data and scaling analysis for forced convection of foams and microfoams in laminar flow in circular and rectangular tubes as well as in tube bundles. Foams and microfoams are pseudoplastic (shear thinning) two-phase fluids consisting of tightly packed bubbles with diameters ranging from tens of microns to a few millimeters. They have found applications in separation processes, soil remediation, oil recovery, water treatment, food processes, as well as in fire fighting and in heat exchangers. First, aqueous solutions of surfactant Tween 20 with different concentrations were used to generate microfoams with various porosity, bubble size distribution, and rheological behavior. These different microfoams were flowed in uniformly heated circular tubes of different diameter instrumented with thermocouples. A wide range of heat fluxes and flow rates were explored. Experimental data were compared with analytical and semi-empirical expressions derived and validated for single-phase power-law fluids. These correlations were extended to two-phase foams by defining the Reynolds number based on the effective viscosity and density of microfoams. However, the local Nusselt and Prandtl numbers were defined based on the specific heat and thermal conductivity of water. Indeed, the heated wall was continuously in contact with a film of water controlling convective heat transfer to the microfoams. Overall, good agreement between experimental results and model predictions was obtained for all experimental conditions considered. Finally, the same approach was shown to be also valid for experimental data reported in the literature for laminar forced convection of microfoams in rectangular minichannels and of macrofoams across aligned and staggered tube bundles with constant wall heat flux.

Natural convection in a vertical heated tube attached to a thermally insulated chimney of a different diameter

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

Asako, Y.; Nakamura, H.; Faghri, M.

1990-08-01

Natural convection is often a convenient and inexpensive mode of heat transfer. It is commonly employed in the cooling of electronic equipment and many other applications. Since the initial work by Bodoia and Osterle (1962) on finite difference solutions of natural convection between vertical isothermal plates, many other researchers have studied natural convection in vertical channels. Specifically Davis and Perona (1971) studied natural convection in vertical heated tubes. A thermally insulated chimney attached to a vertical heated channel induces an increase in the natural convection in the channel and leads to a higher heat transfer rate. This is the well-knownmore » chimney effect discussed in the paper by Haaland and Sparrow (1983). If the chimney diameter is larger than the heated tube diameter, the friction loss in the chimney region decreases with increasing chimney diameter. This induces an increase in the mass flow rate and leads to a higher heat transfer rate than the case for a chimney of the same diameter. However, from a geometric consideration it is evident that the chimney effect diminishes in the limiting case of an extremely large chimney diameter compared with its height. Therefore, there exists an optimum diameter where the heat transfer is maximum. To investigate the chimney effect computations are carried out for a Rayleigh number of 12.5, based on the heated tube radius, and for a Prandtl number of 0.7. The numerical results are based on a control volume finite difference method. The average Nusselt number results are compared with the numerical results obtained for a chimney attached to a tube of the same diameter.« less

Effect of Intraoral Aging on Debris Accumulation and Friction of First Molar Tubes.

PubMed

Chaptini, Edmond; Khoury, Elie; Cacciafesta, Vittorio; Naaman, Nada

2016-11-01

The aim of this article was to evaluate the impact of intraoral aging and site specificity on debris accumulation and friction in molar tubes after intraoral use. A total of 80 intraorally used first molar convertible tubes were provided by 20 orthodontic adolescent patients after 6 months of treatment. The specimens were divided into eight groups (n = 10) according to the mouth quadrant and the type of examination [four groups of ten tubes for scanning electron microscope (SEM) and four groups of ten tubes for friction test]. Scanning electron microscope examination was performed after opening the convertible caps and friction test was executed using a 0.019'' × 0.025'' stainless steel wire, which was inserted in the tubes belonging to each group. The Mann-Whitney test, analysis of variance (ANOVA), and Bonferroni tests were performed for statistical analysis at 0.01 level of significance. There was a significant increase in the amount of debris and frictional force after 6 months of intraoral exposure (p < 0.0001). Debris scores were higher (10% increase) on the upper tubes when compared with the lower ones, with no statistical difference. Mean frictional force ranged from 0.22 to 0.26 N according to the mouth quadrant, but the difference between groups was also not significant. After 6 months of intraoral exposure, there was a significant increase in the amount of debris in the first molar tube slots, leading to significantly higher frictional forces during sliding mechanics. The influence of site specificity on the amount of debris and on frictional forces of the first molar tubes could not be demonstrated. Molar tubes should be cleaned, before and during sliding mechanics, in order to minimize friction.

Detecting interferences with iOS applications to measure speed of sound

NASA Astrophysics Data System (ADS)

Yavuz, Ahmet; Kağan Temiz, Burak

2016-01-01

Traditional experiments measuring the speed of sound consist of studying harmonics by changing the length of a glass tube closed at one end. In these experiments, the sound source and observer are outside of the tube. In this paper, we propose the modification of this old experiment by studying destructive interference in a pipe using a headset, iPhone and iPad. The iPhone is used as an emitter with signal generator application and the iPad is used as the receiver with a spectrogram application. Two experiments are carried out for measures: the emitter inside of the tube with the receiver outside, and vice versa. We conclude that it is even possible to adequately and easily measure the speed of sound using a cup or a can of coke with the method described in this paper.

Adjustable-Pressure Mandrel For Making Composite Tubes

NASA Technical Reports Server (NTRS)

Jacoy, Paul J.; Schmitigal, Wesley P.

1993-01-01

Inflatable inner mandrel enables application of any desired pressure (within reasonable limits) during curing stage in fabrication of fiber/matrix composite tube. Consists mainly of sheath of silicone rubber sealed on aluminum tube. Composite material laid up on mandrel and enclosed in rigid outer die. Sheath on inner mandrel inflated to requisite pressure and regulated during curing. Assembly then placed in oven and cured at specified temperature.

Measuring Libraries' Use of YouTube as a Promotional Tool: An Exploratory Study and Proposed Best Practices

ERIC Educational Resources Information Center

Colburn, Selene; Haines, Laura

2012-01-01

With the emergence of social networking and Web 2.0 applications, libraries have the means to reach users through interactive Web-based tools patrons already use in their personal lives, such as Facebook and YouTube. In this study the authors aim to understand the ways that libraries are using YouTube for outreach purposes. Using a methodology…

Endobronchial intubation detected by insertion depth of endotracheal tube, bilateral auscultation, or observation of chest movements: randomised trial.

PubMed

Sitzwohl, Christian; Langheinrich, Angelika; Schober, Andreas; Krafft, Peter; Sessler, Daniel I; Herkner, Harald; Gonano, Christopher; Weinstabl, Christian; Kettner, Stephan C

2010-11-09

To determine which bedside method of detecting inadvertent endobronchial intubation in adults has the highest sensitivity and specificity. Prospective randomised blinded study. Department of anaesthesia in tertiary academic hospital. 160 consecutive patients (American Society of Anesthesiologists category I or II) aged 19-75 scheduled for elective gynaecological or urological surgery. Patients were randomly assigned to eight study groups. In four groups, an endotracheal tube was fibreoptically positioned 2.5-4.0 cm above the carina, whereas in the other four groups the tube was positioned in the right mainstem bronchus. The four groups differed in the bedside test used to verify the position of the endotracheal tube. To determine whether the tube was properly positioned in the trachea, in each patient first year residents and experienced anaesthetists were randomly assigned to independently perform bilateral auscultation of the chest (auscultation); observation and palpation of symmetrical chest movements (observation); estimation of the position of the tube by the insertion depth (tube depth); or a combination of all three (all three). Correct and incorrect judgments of endotracheal tube position. 160 patients underwent 320 observations by experienced and inexperienced anaesthetists. First year residents missed endobronchial intubation by auscultation in 55% of cases and performed significantly worse than experienced anaesthetists with this bedside test (odds ratio 10.0, 95% confidence interval 1.4 to 434). With a sensitivity of 88% (95% confidence interval 75% to 100%) and 100%, respectively, tube depth and the three tests combined were significantly more sensitive for detecting endobronchial intubation than auscultation (65%, 49% to 81%) or observation(43%, 25% to 60%) (P<0.001). The four tested methods had the same specificity for ruling out endobronchial intubation (that is, confirming correct tracheal intubation). The average correct tube insertion depth was 21 cm in women and 23 cm in men. By inserting the tube to these distances, however, the distal tip of the tube was less than 2.5 cm away from the carina (the recommended safety distance, to prevent inadvertent endobronchial intubation with changes in the position of the head in intubated patients) in 20% (24/118) of women and 18% (7/42) of men. Therefore optimal tube insertion depth was considered to be 20 cm in women and 22 cm in men. Less experienced clinicians should rely more on tube insertion depth than on auscultation to detect inadvertent endobronchial intubation. But even experienced physicians will benefit from inserting tubes to 20-21 cm in women and 22-23 cm in men, especially when high ambient noise precludes accurate auscultation (such as in emergency situations or helicopter transport). The highest sensitivity and specificity for ruling out endobronchial intubation, however, is achieved by combining tube depth, auscultation of the lungs, and observation of symmetrical chest movements. NCT01232166.

Torch kit for welding in difficult areas

NASA Technical Reports Server (NTRS)

Stein, J. A.

1971-01-01

Miniature tungsten inert gas welding torch, used with variously formed interchangeable soft copper tubing extensions, provides inexpensive, accurate welding capability for inaccessible joints. Kit effectively welds stainless steel tubing 0.089 cm thick. Other applications are cited.

Proceedings of the first switch tube advanced technology meeting held at EG G, Salem, Massachusetts, May 23, 1990

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

Shuman, A.; Beavis, L.

Early in 1990, J. A. Wilder, Supervisor of Sandia National Laboratories (SNLA), Division 2565 requested that a meeting of the scientists and engineers responsible for developing and producing switch tubes be set up to discuss in a semi-formal way the science and technology of switch tubes. Programmatic and administrative issues were specifically exempted from the discussions. L. Beavis, Division 7471, SNL and A. Shuman, EG G, Salem were made responsible for organizing a program including the materials and processes of switch tubes. The purpose of the Switch Tube Advanced Technology meeting was to allow personnel from Allied Signal Kansas Citymore » Division (AS/KCD); EG G, Salem and Sandia National Laboratories (SNL) to discuss a variety of issues involved in the development and production of switch tubes. It was intended that the formal and informal discussions would allow a better understanding of the production problems by material and process engineers and of the materials and processes by production engineers. This program consisted of formal presentations on May 23 and informal discussions on May 24. The topics chosen for formal presentation were suggested by the people of AS/KCD, EG G, Salem, and SNL involved with the design, development and production of switch tubes. The topics selected were generic. They were not directed to any specific switch tube but rather to all switch tubes in production and development. This document includes summaries of the material presented at the formal presentation on May 23.« less

Development of a highly sensitive one-tube nested real-time PCR for detecting Mycobacterium tuberculosis.

PubMed

Choi, Yeonim; Jeon, Bo-Young; Shim, Tae Sun; Jin, Hyunwoo; Cho, Sang-Nae; Lee, Hyeyoung

2014-12-01

Rapid, accurate detection of Mycobacterium tuberculosis is crucial in the diagnosis of tuberculosis (TB), but conventional diagnostic methods have limited sensitivity and specificity or are time consuming. A new highly sensitive nucleic acid amplification test, combined nested and real-time polymerase chain reaction (PCR) in a single tube (one-tube nested real-time PCR), was developed for detecting M. tuberculosis, which takes advantage of two PCR techniques, i.e., nested PCR and real-time PCR. One-tube nested real-time PCR was designed to have two sequential reactions with two sets of primers and dual probes for the insertion sequence (IS) 6110 sequence of M. tuberculosis in a single closed tube. The minimum limits of detection of IS6110 real-time PCR and IS6110 one-tube nested real-time PCR were 100 fg/μL and 1 fg/μL of M. tuberculosis DNA, respectively. AdvanSure TB/non-tuberculous mycobacteria (NTM) real-time PCR, IS6110 real-time PCR, and two-tube nested real-time PCR showed 100% sensitivity and 100% specificity for clinical M. tuberculosis isolates and NTM isolates. In comparison, the sensitivities of AdvanSure TB/NTM real-time PCR, single IS6110 real-time PCR, and one-tube nested real-time PCR were 91% (152/167), 94.6% (158/167), and 100% (167/167) for sputum specimens, respectively. In conclusion, IS6110 one-tube nested real-time PCR is useful for detecting M. tuberculosis due to its high sensitivity and simple manipulation. Copyright © 2014 Elsevier Inc. All rights reserved.

Cost-Effective Fabrication of Wettability Gradient Copper Surface by Screen Printing and its Application to Condensation Heat Transfer

NASA Astrophysics Data System (ADS)

Leu, Tzong-Shyng; Huang, Hung-Ming; Huang, Ding-Jun

2016-06-01

In this paper, wettability gradient pattern is applied to condensation heat transfer on a copper tube surface. For this application, the vital issue is how to fabricate gradient patterns on a curve tube surface to accelerate the droplet collection efficiently. For this purpose, novel fabrication processes are developed to form wettability gradient patterns on a curve copper tube surface by using roller screen printing surface modification techniques. The roller screen printing surface modification techniques can easily realize wettability gradient surfaces with superhydrophobicity and superhydrophilicity on a copper tube surface. Experimental results show the droplet nucleation sites, movement and coalescence toward the collection areas can be effectively controlled which can assist in removing the condensation water from the surface. The effectiveness of droplet collection is appropriate for being applied to condensation heat transfer in the foreseeable future.

Receptor-Like Kinase RUPO Interacts with Potassium Transporters to Regulate Pollen Tube Growth and Integrity in Rice

PubMed Central

Liu, Lingtong; Zheng, Canhui; Kuang, Baijan; Wei, Liqin; Yan, Longfeng; Wang, Tai

2016-01-01

During sexual reproduction of flowering plants, the pollen tube grows fast and over a long distance within the pistil to deliver two sperms for double fertilization. Growing plant cells need to communicate constantly with external stimuli as well as monitor changes in surface tension of the cell wall and plasma membrane to coordinate these signals and internal growth machinery; however, the underlying mechanisms remain largely unknown. Here we show that the rice member of plant-specific receptor-like kinase CrRLK1Ls subfamily, Ruptured Pollen tube (RUPO), is specifically expressed in rice pollen. RUPO localizes to the apical plasma membrane and vesicle of pollen tubes and is required for male gamete transmission. K+ levels were greater in pollen of homozygous CRISPR-knockout lines than wild-type plants, and pollen tubes burst shortly after germination. We reveal the interaction of RUPO with high-affinity potassium transporters. Phosphorylation of RUPO established and dephosphorylation abolished the interaction. These results have revealed the receptor-like kinase as a regulator of high-affinity potassium transporters via phosphorylation-dependent interaction, and demonstrated a novel receptor-like kinase signaling pathway that mediates K+ homeostasis required for pollen tube growth and integrity. PMID:27447945

Effect of gravity orientation on the thermal performance of Stirling-type pulse tube cryocoolers

NASA Astrophysics Data System (ADS)

Ross, Ronald G.; Johnson, Dean L.

2004-06-01

The effect of angular orientation on the off-state conduction of pulse tube cryocoolers has been previously explored, as has the effect of orientation on the thermal performance of low-frequency (˜2 Hz) GM-style pulse tube refrigerators. The significant effects that have been found are well explained by the presence of free convection that builds up in the hollow pulse tube when the hot end of the pulse tube is not higher than the cold end. This paper extends the investigation of angular orientation effects to the refrigeration performance of high frequency (˜40 Hz) Stirling-type pulse tube cryocoolers typical of those used in long-life space applications. Strong orientation effects on the performance of such cryocoolers have recently been observed during system-level testing of both linear and U-tube type pulse tubes. To quantify the angular dependency effects, data have been gathered on both U-tube and linear type pulse tubes of two different manufacturers as a function of orientation angle, cold-tip temperature, and compressor stroke.

Lifespan estimation of seal welded super stainless steels for water condenser of nuclear power plants

NASA Astrophysics Data System (ADS)

Kim, Young Sik; Park, Sujin; Chang, Hyun Young

2014-01-01

When sea water was used as cooling water for water condenser of nuclear power plants, commercial stainless steels can not be applied because chloride concentration exceeds 20,000 ppm. There are many opinions for the materials selection of tube and tube sheets of a condenser. This work reviewed the application guide line of stainless steels for sea-water facilities and the estimation equations of lifespan were proposed from the analyses of both field data for sea water condenser and experimental results of corrosion. Empirical equations for lifespan estimation were derived from the pit initiation time and re-tubing time of stainless steel tubing in sea water condenser of nuclear power plants. The lifespan of seal-welded super austenitic stainless steel tube/tube sheet was calculated from these equations. Critical pitting temperature of seal-welded PRE 50 grade super stainless steel was evaluated as 60 °C. Using the proposed equation in engineering aspect, tube pitting corrosion time of seal-welded tube/tube sheet was calculated as 69.8 years and re-tubing time was estimated as 82.0 years.

White Thrombus Formation in Blood Tubing Lines in a Chronic Hemodialysis Unit

PubMed Central

Watnick, Suzanne; Stooksbury, Michael; Winter, Rolf; Riscoe, Michael; Cohen, David M.

2008-01-01

Background and objectives: Previous reports have described white particulate matter in banked blood components, but no prior public reports describe such matter in blood tubing during the course of routine in-center hemodialysis. This report describes the events, investigations, and preliminary conclusions associated with the spontaneous formation of adherent white thrombus in the venous and arterial blood lines during routine in-center hemodialysis treatments. Design setting, participants, & measurements: This investigation occurred at the Portland Veterans Administration Medical Center (PVAMC) Hemodialysis Unit from October 2006 through April 2007. Sixty-eight variables regarding demographics, medical history and dialysis treatments were collected on our 34 chronic hemodialysis outpatients. Results: Over a 5-wk interval, 62% (21 of 34) of the chronic hemodialysis patients unexpectedly developed a white precipitate adhering to the lumenal surface of their dialysis blood tubing, with 73 of 580 chronic dialysis treatments exhibiting the phenomenon. Microscopic and biochemical analyses were consistent with white thrombus, formed by an aggregation of platelets and fibrin. An alert was issued and other in-center hemodialysis units noted similar findings. This was remedied by the removal of specific tubing. Conclusions: Both patient-specific and tubing-specific factors may have been operative. Although patient safety was not adversely affected, assessment of clinical and manufacturing variables potentially affecting platelet activation is warranted. PMID:18184880

White thrombus formation in blood tubing lines in a chronic hemodialysis unit.

PubMed

Watnick, Suzanne; Stooksbury, Michael; Winter, Rolf; Riscoe, Michael; Cohen, David M

2008-03-01

Previous reports have described white particulate matter in banked blood components, but no prior public reports describe such matter in blood tubing during the course of routine in-center hemodialysis. This report describes the events, investigations, and preliminary conclusions associated with the spontaneous formation of adherent white thrombus in the venous and arterial blood lines during routine in-center hemodialysis treatments. Design setting, participants, & measurements: This investigation occurred at the Portland Veterans Administration Medical Center (PVAMC) Hemodialysis Unit from October 2006 through April 2007. Sixty-eight variables regarding demographics, medical history and dialysis treatments were collected on our 34 chronic hemodialysis outpatients. Over a 5-wk interval, 62% (21 of 34) of the chronic hemodialysis patients unexpectedly developed a white precipitate adhering to the lumenal surface of their dialysis blood tubing, with 73 of 580 chronic dialysis treatments exhibiting the phenomenon. Microscopic and biochemical analyses were consistent with white thrombus, formed by an aggregation of platelets and fibrin. An alert was issued and other in-center hemodialysis units noted similar findings. This was remedied by the removal of specific tubing. Both patient-specific and tubing-specific factors may have been operative. Although patient safety was not adversely affected, assessment of clinical and manufacturing variables potentially affecting platelet activation is warranted.

Traveling-wave tube reliability estimates, life tests, and space flight experience

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Speck, C. E.

1977-01-01

Infant mortality, useful life, and wearout phase of twt life are considered. The performance of existing developmental tubes, flight experience, and sequential hardware testing are evaluated. The reliability history of twt's in space applications is documented by considering: (1) the generic parts of the tube in light of the manner in which their design and operation affect the ultimate reliability of the device, (2) the flight experience of medium power tubes, and (3) the available life test data for existing space-qualified twt's in addition to those of high power devices.

Development of an X-band 25 watt traveling-wave tube

NASA Technical Reports Server (NTRS)

Roberts, L. A.; Knight, R. I.

1972-01-01

The development of a 25 watt high efficiency travelingwave tube at 8.5 GHz for space communications and telemetry applications is reported. Described is the design basis for the tube, which is known as the WJ-3703. Because of the combined high efficiency and high frequency requirements, the helix and body dimensions are very small and require special techniques for various assembly and construction procedures. These are described in detail. Measurement results of focusing tests and RF operation are given, but only pulsed RF performance of the tubes was obtained.

Los Alamos National Laboratory W76 Pit Tube Lifetime Study

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

Abeln, Terri G.

2012-04-25

A metallurgical study was requested as part of the Los Alamos National Laboratory (LANL) W76-1 life-extension program (LEP) involving a lifetime analysis of type 304 stainless steel pit tubes subject to repeat bending loads during assembly and disassembly operations at BWXT/Pantex. This initial test phase was completed during the calendar years of 2004-2006 and the report not issued until additional recommended tests could be performed. These tests have not been funded to this date and therefore this report is considered final. Tubes were reportedly fabricated according to Rocky Flats specification P14548 - Seamless Type 304 VIM/VAR Stainless Steel Tubing. Tubemore » diameter was specified as 0.125 inches and wall thickness as 0.028 inches. A heat treat condition is not specified and the hardness range specification can be characteristic of both 1/8 and 1/4 hard conditions. Properties of all tubes tested were within specification. Metallographic analysis could not conclusively determine a specified limit to number of bends allowable. A statistical analysis suggests a range of 5-7 bends with a 99.95% confidence limit. See the 'Statistical Analysis' section of this report. The initial phase of this study involved two separate sets of test specimens. The first group was part of an investigation originating in the ESA-GTS [now Gas Transfer Systems (W-7) Group]. After the bend cycle test parameters were chosen (all three required bends subjected to the same amount of bend cycles) and the tubes bent, the investigation was transferred to Terri Abeln (Metallurgical Science and Engineering) for analysis. Subsequently, another limited quantity of tubes became available for testing and were cycled with the same bending fixture, but with different test parameters determined by T. Abeln.« less

Visual loop-mediated isothermal amplification (LAMP) for the rapid diagnosis of Enterocytozoon hepatopenaei (EHP) infection.

PubMed

T, Sathish Kumar; A, Navaneeth Krishnan; J, Joseph Sahaya Rajan; M, Makesh; K P, Jithendran; S V, Alavandi; K K, Vijayan

2018-05-01

The emerging microsporidian parasite Enterocytozoon hepatopenaei (EHP), the causative agent of hepatopancreatic microsporidiosis, has been widely reported in shrimp-farming countries. EHP infection can be detected by light microscopy observation of spores (1.7 × 1 μm) in stained hepatopancreas (HP) tissue smears, HP tissue sections, and fecal samples. EHP can also be detected by polymerase chain reaction (PCR) targeting the small subunit (SSU) ribosomal RNA (rRNA) gene or the spore wall protein gene (SWP). In this study, a rapid, sensitive, specific, and closed tube visual loop-mediated isothermal amplification (LAMP) protocol combined with FTA cards was developed for the diagnosis of EHP. LAMP primers were designed based on the SSU rRNA gene of EHP. The target sequence of EHP was amplified at constant temperature of 65 °C for 45 min and amplified LAMP products were visually detected in a closed tube system by using SYBR™ green I dye. Detection limit of this LAMP protocol was ten copies. Field and clinical applicability of this assay was evaluated using 162 field samples including 106 HP tissue samples and 56 fecal samples collected from shrimp farms. Out of 162 samples, EHP could be detected in 62 samples (47 HP samples and 15 fecal samples). When compared with SWP-PCR as the gold standard, this EHP LAMP assay had 95.31% sensitivity, 98.98% specificity, and a kappa value of 0.948. This simple, closed tube, clinically evaluated visual LAMP assay has great potential for diagnosing EHP at the farm level, particularly under low-resource circumstances.

Development of very small-diameter, inductively coupled magnetized plasma device

NASA Astrophysics Data System (ADS)

Kuwahara, D.; Mishio, A.; Nakagawa, T.; Shinohara, S.

2013-10-01

In order to miniaturize a high-density, inductively coupled magnetized plasma or helicon plasma to be applied to, e.g., an industrial application and an electric propulsion field, small helicon device has been developed. The specifications of this device along with the experimental results are described. We have succeeded in generating high-density (˜1019 m-3) plasmas using quartz tubes with very small diameters of 10 and 20 mm, with a radio frequency power ˜1200 and 700 W, respectively, in the presence of the magnetic field less than 1 kG.

Development of very small-diameter, inductively coupled magnetized plasma device.

PubMed

Kuwahara, D; Mishio, A; Nakagawa, T; Shinohara, S

2013-10-01

In order to miniaturize a high-density, inductively coupled magnetized plasma or helicon plasma to be applied to, e.g., an industrial application and an electric propulsion field, small helicon device has been developed. The specifications of this device along with the experimental results are described. We have succeeded in generating high-density (~10(19) m(-3)) plasmas using quartz tubes with very small diameters of 10 and 20 mm, with a radio frequency power ~1200 and 700 W, respectively, in the presence of the magnetic field less than 1 kG.

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

NASA Technical Reports Server (NTRS)

Kaufman, A.

1982-01-01

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

Radiation pager

NASA Astrophysics Data System (ADS)

Warren, John L.; Vadnais, Kenneth G.

1997-01-01

Recent advances in miniature photomultiplier tubes and low power electronics have made possible a new generation of small gamma-ray radiation detectors specifically designed for use by government and law enforcement agencies for the detection and interdiction of concealed nuclear materials. This paper describes an inexpensive pager sized radiation detector that can be worn on the belt or carried in a pocket for hands free operation, and which can quietly alert the operator to the presence of nuclear material. The sensitivity performance of the detector technology and the application of the instrument to law enforcement and nuclear smuggling are discussed.

Experimental and statistical study on fracture boundary of non-irradiated Zircaloy-4 cladding tube under LOCA conditions

NASA Astrophysics Data System (ADS)

Narukawa, Takafumi; Yamaguchi, Akira; Jang, Sunghyon; Amaya, Masaki

2018-02-01

For estimating fracture probability of fuel cladding tube under loss-of-coolant accident conditions of light-water-reactors, laboratory-scale integral thermal shock tests were conducted on non-irradiated Zircaloy-4 cladding tube specimens. Then, the obtained binary data with respect to fracture or non-fracture of the cladding tube specimen were analyzed statistically. A method to obtain the fracture probability curve as a function of equivalent cladding reacted (ECR) was proposed using Bayesian inference for generalized linear models: probit, logit, and log-probit models. Then, model selection was performed in terms of physical characteristics and information criteria, a widely applicable information criterion and a widely applicable Bayesian information criterion. As a result, it was clarified that the log-probit model was the best among the three models to estimate the fracture probability in terms of the degree of prediction accuracy for both next data to be obtained and the true model. Using the log-probit model, it was shown that 20% ECR corresponded to a 5% probability level with a 95% confidence of fracture of the cladding tube specimens.

PLC-Mediated Signaling Pathway in Pollen Tubes Regulates the Gametophytic Self-incompatibility of Pyrus Species

PubMed Central

Qu, Haiyong; Guan, Yaqin; Wang, Yongzhang; Zhang, Shaolin

2017-01-01

Among the Rosaceae species, the gametophytic self-incompatibility (GSI) is controlled by a single multi-allelic S locus, which is composed of the pistil-S and pollen-S genes. The pistil-S gene encodes a polymorphic ribonuclease (S-RNase), which is essential for identifying self-pollen. However, the S-RNase system has not been fully characterized. In this study, the self-S-RNase inhibited the Ca2+-permeable channel activity at pollen tube apices and the selectively decreased phospholipase C (PLC) activity in the plasma membrane of Pyrus pyrifolia pollen tubes. Self-S-RNase decreased the Ca2+ influx through a PLC-mediated signaling pathway. Phosphatidylinositol-specific PLC has a 26-amino acid insertion in pollen tubes of the ‘Jinzhuili’ cultivar, which is a spontaneous self-compatible mutant of the ‘Yali’ cultivar. ‘Yali’ plants exhibit a typical S-RNase-based GSI. Upon self-pollination, PLC gene expression is significantly higher in ‘Jinzhuili’ pollen tubes than that in ‘Yali’ pollen tubes. Moreover, the PLC in pollen tubes can only interact with one of the two types of S-RNase from the style. In the Pyrus x bretschneideri Rehd, the PLC directly interacted with the S7-RNase in the pollen tube, but not with the S34-RNase. Collectively, our results reveal that the effects of S-RNase on PLC activity are required for S-specific pollen rejection, and that PLC-IP3 participates in the self-incompatibility reaction of Pyrus species. PMID:28729872

PLC-Mediated Signaling Pathway in Pollen Tubes Regulates the Gametophytic Self-incompatibility of Pyrus Species.

PubMed

Qu, Haiyong; Guan, Yaqin; Wang, Yongzhang; Zhang, Shaolin

2017-01-01

Among the Rosaceae species, the gametophytic self-incompatibility (GSI) is controlled by a single multi-allelic S locus, which is composed of the pistil-S and pollen-S genes. The pistil-S gene encodes a polymorphic ribonuclease (S-RNase), which is essential for identifying self-pollen. However, the S-RNase system has not been fully characterized. In this study, the self-S-RNase inhibited the Ca 2+ -permeable channel activity at pollen tube apices and the selectively decreased phospholipase C ( PLC ) activity in the plasma membrane of Pyrus pyrifolia pollen tubes. Self-S-RNase decreased the Ca 2+ influx through a PLC -mediated signaling pathway. Phosphatidylinositol-specific PLC has a 26-amino acid insertion in pollen tubes of the 'Jinzhuili' cultivar, which is a spontaneous self-compatible mutant of the 'Yali' cultivar. 'Yali' plants exhibit a typical S-RNase-based GSI. Upon self-pollination, PLC gene expression is significantly higher in 'Jinzhuili' pollen tubes than that in 'Yali' pollen tubes. Moreover, the PLC in pollen tubes can only interact with one of the two types of S-RNase from the style. In the Pyrus x bretschneideri Rehd, the PLC directly interacted with the S 7 -RNase in the pollen tube, but not with the S 34 -RNase. Collectively, our results reveal that the effects of S-RNase on PLC activity are required for S-specific pollen rejection, and that PLC -IP 3 participates in the self-incompatibility reaction of Pyrus species.

Cell-Cell Interactions during pollen tube guidance

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

Daphne Preuss

The long-term goal of this research is to identify the signaling molecules that mediate plant cell-cell interactions during pollination. The immediate goals of this project are to perform genetic and molecular analysis of pollen tube guidance. Specifically, we proposed to: 1. Characterize the pistil components that direct pollen tube navigation using the Arabidopsis thaliana in vitro pollen tube guidance system 2. Identify pistil signals that direct pollen tube guidance by a) using microarrays to profile gene expression in developing pistils, and b) employing proteomics and metabolomics to isolate pollen tube guidance signals. 3. Explore the genetic basis of natural variationmore » in guidance signals, comparing the in vitro interactions between pollen and pistils from A. thaliana and its close relatives.« less

A novel investigation of heat transfer characteristics in rifled tubes

NASA Astrophysics Data System (ADS)

Jegan, C. Dhayananth; Azhagesan, N.

2018-05-01

The experimental investigation of heat transfer of water flowing in a rifled tube was explored at different pressures and at various operating conditions in a rifled tube heat exchanger. The specifications for the inner and outer diameters of the inner tube are 25.8 and 50.6 mm, respectively. The working fluids used in shell side and tube side are cold and hot water. The rifled tube was made of the stainless steel with 4 ribs, 50.6 mm outer diameter, 0.775 mm rib height, 58o helix angle and the length 1500 mm. The effect of pressure, wall heat flux and friction factor were discussed. The results confirm that even at low pressures the rifled tubes has an obvious enhancement in heat transfer compared with smooth tube. Results depicts that the Nusselt number increases with Reynolds number and the friction factor decreases with increase in Reynolds number and the heat transfer rate is higher for the rifled tube when compared to smooth tube, because of strong swirl flow due to centrifugal action. It also confirms that, the friction factor obtained from the rifled tube is significantly higher than that of smooth tube.

Wound tube heat exchanger

DOEpatents

Ecker, Amir L.

1983-01-01

What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

The temperature dependence of the tensile properties of thermally treated Alloy 690 tubing

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

Harrod, D.L.; Gold, R.E.; Larsson, B.

1992-12-31

Tensile tests were run in air on full tube cross-sections of 22.23 mm OD by 1.27 mm wall thickness Alloy 690 steam generator production tubes from ten (10) heats of material at eight (8) temperatures between room temperature and 760{degrees}C. The tubing was manufactured to specification requirements consistent with the EPRI guidelines for Alloy 690 tubing. The room temperature stress-strain curves are described quite well by the Voce equation. Ductile fracture by dimpled rupture was observed at all test temperatures. The elevated temperature tensile properties are compared with design data given in the ASME Code.

Metal glass vacuum tube solar collectors are approaching lower-medium temperature heat application.

PubMed

Jiang, Xinian

2010-04-26

Solar thermal collectors are widely used worldwide mainly for hot water preparation at a low temperature (less than 80 degrees C). Applications including many industrial processes and central air conditioning with absorption chillers, instead require lower-medium temperature heat (between 90 degrees C and 150 degrees C) to be driven when using solar thermal energy. The metal absorber glass vacuum tube collectors (MGVT) are developed for this type of applications. Current state-of-art and possible future technology development of MGVT are presented.

Intricate Hollow Structures: Controlled Synthesis and Applications in Energy Storage and Conversion.

PubMed

Zhou, Liang; Zhuang, Zechao; Zhao, Huihui; Lin, Mengting; Zhao, Dongyuan; Mai, Liqiang

2017-05-01

Intricate hollow structures garner tremendous interest due to their aesthetic beauty, unique structural features, fascinating physicochemical properties, and widespread applications. Here, the recent advances in the controlled synthesis are discussed, as well as applications of intricate hollow structures with regard to energy storage and conversion. The synthetic strategies toward complex multishelled hollow structures are classified into six categories, including well-established hard- and soft-templating methods, as well as newly emerging approaches based on selective etching of "soft@hard" particles, Ostwald ripening, ion exchange, and thermally induced mass relocation. Strategies for constructing structures beyond multishelled hollow structures, such as bubble-within-bubble, tube-in-tube, and wire-in-tube structures, are also covered. Niche applications of intricate hollow structures in lithium-ion batteries, Li-S batteries, supercapacitors, Li-O 2 batteries, dye-sensitized solar cells, photocatalysis, and fuel cells are discussed in detail. Some perspectives on the future research and development of intricate hollow structures are also provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Temperature Profile in Fuel and Tie-Tubes for Nuclear Thermal Propulsion Systems

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

Vishal Patel

A finite element method to calculate temperature profiles in heterogeneous geometries of tie-tube moderated LEU nuclear thermal propulsion systems and HEU designs with tie-tubes is developed and implemented in MATLAB. This new method is compared to previous methods to demonstrate shortcomings in those methods. Typical methods to analyze peak fuel centerline temperature in hexagonal geometries rely on spatial homogenization to derive an analytical expression. These methods are not applicable to cores with tie-tube elements because conduction to tie-tubes cannot be accurately modeled with the homogenized models. The fuel centerline temperature directly impacts safety and performance so it must be predictedmore » carefully. The temperature profile in tie-tubes is also important when high temperatures are expected in the fuel because conduction to the tie-tubes may cause melting in tie-tubes, which may set maximum allowable performance. Estimations of maximum tie-tube temperature can be found from equivalent tube methods, however this method tends to be approximate and overly conservative. A finite element model of heat conduction on a unit cell can model spatial dependence and non-linear conductivity for fuel and tie-tube systems allowing for higher design fidelity of Nuclear Thermal Propulsion.« less

Heat removal capability of divertor coaxial tube assembly

NASA Astrophysics Data System (ADS)

Shibui, Masanao; Nakahira, Masataka; Tada, Eisuke; Takatsu, Hideyuki

1994-05-01

To deal with high power flowing in the divertor region, an advanced divertor concept with gas target has been proposed for use in ITER/EDA. The concept uses a divertor channel to remove the radiated power while allowing neutrals to recirculate. Candidate channel wall designs include a tube array design where many coaxial tubes are arranged in the toroidal direction to make louver. The coaxial tube consists of a Be protection tube encases many supply tubes wound helically around a return tube. V-alloy and hardened Cu-alloy have been proposed for use in the supply and return tubes. Some coolants have also been proposed for the design including pressurized He and liquid metals, because these coolants are consistent with the selection of coolants for the blanket and also meet the requirement of high temperature operation. In the coaxial tube design, the coolant area is restricted and brittle Be material is used under severe thermal cyclings. Thus, to obtain the coaxial tube with sufficient safety margin for the expected fusion power excursion, it is essential to understand its applicability limit. The paper discusses heat removal capability of the coaxial tube and recommends some design modifications.

Large co-axial pulse tube preliminary results

NASA Astrophysics Data System (ADS)

Emery, N.; Caughley, A.; Meier, J.; Nation, M.; Tanchon, J.; Trollier, T.; Ravex, A.

2014-01-01

We report that Callaghan Innovation, formally known as Industrial Research Ltd (IRL), has designed and built its largest of three high frequency single-stage co-axial pulse tubes, closely coupled to a metal diaphragm pressure wave generator (PWG). The previous pulse tube achieved 110 W of cooling power @ 77 K, with an electrical input power of 3.1 kW from a 90 cc swept volume PWG. The pulse tubes have all been tuned to operate at 50 Hz, with a mean helium working pressure of 2.5 MPa. Sage pulse tube simulation software was used to model the latest pulse tube and predicted 280 W of cooling power @ 77 K. The nominal 250 W cryocooler was designed to be an intermediate step to up-scale pulse tube technology for our 1000 cc swept-volume PWG, to provide liquefaction of gases and cooling for HTS applications. Details of the modeling, design, development and preliminary experimental results are discussed.

Use of radio frequency identification (RFID) tags in bedside monitoring of endotracheal tube position.

PubMed

Reicher, Joshua; Reicher, Danielle; Reicher, Murray

2007-06-01

Improper positioning of the endotracheal tube during intubation poses a serious health risk to patients. In one prospective study of 219 critically ill patients, 14% required endotracheal tube repositioning after intubation [Brunel et al. Chest 1989; 96: 1043-1045] While a variety of techniques are used to confirm proper tube placement, a chest X-ray is usually employed for definitive verification. Radio frequency identification (RFID) technology, in which an RFID reader emits and receives a signal from an RFID tag, may be useful in evaluating endotracheal tube position. RFID technology has already been approved for use in humans as a safe and effective tool in a variety of applications. The use of handheld RFID detectors and RFID tag-labeled endotracheal tubes could allow for easy and accurate bedside monitoring of endotracheal tube position, once initial proper placement is confirmed.

Characterization of Long SiAION Ceramic Tubes for Gun Barrel Applications

DTIC Science & Technology

2006-06-01

sintering kinetics during the sintering of regions with different starting densities can all lead to the production of tubes with gradients in strength and...variations of dimensions. These gradients and deviations from anticipated dimensions all detract from the ability of the manufactured product to be...characteristics of the tubes can be introduced at various steps in the production process. When the powder is initially loaded to be cold

Proceedings of the International Cryocooler Conference (7th) Held in Santa Fe, New Mexico on 17-19 November 1992. Part 3

DTIC Science & Technology

1993-04-01

Stirling Cryocoolers , Pulse Tube Refrigerators, Novel Concepts and Component Development, Low Temperature Regenerator Development...topics included Cryocooler Testing and Modeling, Space and Long Life Applications, Stirling Cryocoolers , Pulse Tube Refrigerators, Novel Concepts and...with bold variables. 785 PL-CP--93-1001 Phasor analysis is useful for regenerative cryocoolers , such as Stirling and pulse tube refrigerators,

Coal-Burning Technologies Applicable to Air Force Central Heating Plants

DTIC Science & Technology

1989-12-01

8 3. DESCRIPTION OF REPLACEMENT OR EXPANSION TECHNOLOGIES ........ 9 3.1.1 Shell (Fire- Tube ) Boilers ........... 9...3.1.2 Water- Tube Boilers .*.*........***.... 10 3.1.3 Packaged vs Field-Erected Construction ...... 11 3.2 STOKER FIRING ...... .. 11 3.2.1 Description...FIGURES 4 Figure Pg 1 Schematic diagram of a typical scotch shell boiler: wet-back, three-pass design ..~............... 9 2 Commnon tube patterns for

An Investigation on Axial Deformation Behavior of Thin-Wall Unfilled and Filled Tube with Aluminum Alloy (Al-Si7Mg) Foam Reinforced with SiC Particles

NASA Astrophysics Data System (ADS)

Kumaraswamidhas, L. A.; Rajak, Dipen Kumar; Das, S.

2016-08-01

The objective of this research is to produce superior quality aluminum alloy foam with low relative density and higher resistance against compression deformation. This investigation has studied crash energy capacities of unfilled and filled aluminum alloy foams in mild steel tubes. The foam has been prepared by the melt route process with an addition of 5wt.% silicon carbide particles. The fabricated aluminum alloy foams were characterized by field emission scanning electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, and Material Pro analyzer. It was observed that the foam-filled tubes could absorb more energy as compared to the unfilled tubes before reaching the complete densification point. Also, the aluminum alloy foams had better energy absorption capacity during the crash or impact loading. This article demonstrates the excellent ability of aluminum alloy foam application in the field where there is a need to absorb crash energy. It is to be noted that the amount of energy absorption will be greater for low-density foam filled in thin-wall rectangular section tubes. We have seen an increasing trend in the application of aluminum foams inside the thin-wall mild steel tubes for maximum energy absorption.

Thermal analysis on x-ray tube for exhaust process

NASA Astrophysics Data System (ADS)

Kumar, Rakesh; Rao Ratnala, Srinivas; Veeresh Kumar, G. B.; Shivakumar Gouda, P. S.

2018-02-01

It is great importance in the use of X-rays for medical purposes that the dose given to both the patient and the operator is carefully controlled. There are many types of the X- ray tubes used for different applications based on their capacity and power supplied. In present thesis maxi ray 165 tube is analysed for thermal exhaust processes with ±5% accuracy. Exhaust process is usually done to remove all the air particles and to degasify the insert under high vacuum at 2e-05Torr. The tube glass is made up of Pyrex material, 95%Tungsten and 5%rhenium is used as target material for which the melting point temperature is 3350°C. Various materials are used for various parts; during the operation of X- ray tube these waste gases are released due to high temperature which in turn disturbs the flow of electrons. Thus, before using the X-ray tube for practical applications it has to undergo exhaust processes. Initially we build MX 165 model to carry out thermal analysis, and then we simulate the bearing temperature profiles with FE model to match with test results with ±5%accuracy. At last implement the critical protocols required for manufacturing processes like MF Heating, E-beam, Seasoning and FT.

In vitro evaluation of an alternative method to bond molar tubes

PubMed Central

PINZAN-VERCELINO, Célia Regina Maio; PINZAN, Arnaldo; GURGEL, Júlio de Araújo; BRAMANTE, Fausto Silva; PINZAN, Luciana Maio

2011-01-01

Despite the advances in bonding materials, many clinicians today still prefer to place bands on molar teeth. Molar bonding procedures need improvement to be widely accepted clinically. Objective The purpose of this study was to evaluate the shear bond strength when an additional adhesive layer was applied on the occlusal tooth/tube interface to provide reinforcement to molar tubes. Material and methods Sixty third molars were selected and allocated to the 3 groups: group 1 received a conventional direct bond followed by the application of an additional layer of adhesive on the occlusal tooth/tube interface, group 2 received a conventional direct bond, and group 3 received a conventional direct bond and an additional cure time of 10 s. The specimens were debonded in a universal testing machine. The results were analyzed statistically by ANOVA and Tukey’s test (α=0.05). Results Group 1 had a significantly higher (p<0.05) shear bond strength compared to groups 2 and 3. No difference was detected between groups 2 and 3 (p>0.05). Conclusions The present in vitro findings indicate that the application of an additional layer of adhesive on the tooth/tube interface increased the shear bond strength of the bonded molar tubes. PMID:21437468

Case studies from Oman for coiled tubing deployed completion techniques

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

Taylor, R.W.; Conrad, B.

1996-09-01

Although the use of ultra-large coiled tubing to complete wells is relatively new, it is gaining widespread industry application. This paper will detail the equipment necessary to perform an operation of this type and will present information from several case studies in Oman in which an operator has successfully deployed completion equipment on 3-1/2-inch-OD coiled tubing. In addition to a discussion of the equipment required to perform the necessary operations, the trial parameters that were established by this operator will be given. The information presented has been selected to allow an initial evaluation to be made of coiled tubing completionsmore » in general and will help to determine whether this method can prove to be less expensive than traditional rig-based completions. The topics presented have been chosen to provide the reader with a thorough understanding of the techniques and preparation needed to execute a coiled tubing completion. The summary of experiences will conclude that this innovative completion technique can be a viable method for completing wells. Although long-term advantages regarding production and well maintenance cannot yet be determined, the operator`s experiences to date have confirmed his initial belief that use of coiled tubing in ultra-large continuous-pipe applications can be cost effective.« less

Acquired tracheoesophageal fistula due to high intracuff pressure.

PubMed

Hameed, Akmal A; Mohamed, Hasan; Al-Mansoori, Motasem

2008-01-01

High-compliance endotracheal tube cuffs are used to prevent gas leak and also pulmonary aspiration in mechanically ventilated patients. However, the use of the usual cuff inflation volumes may cause tracheal damage and lead to tracheoesophageal fistula.Tracheostomy tube cuffs seal against the tracheal wall and prevent leakage of air around the tube, assuring that the tidal volume is delivered to the lungs. In the past, high-pressure cuffs were used, but these contributed to tracheal injury and have been replaced by high-volume, low-pressure cuffs. For long-term applications, some newer tubes have low-profile (tight to shaft) cuffs that facilitate the tracheostomy tube changes by eliminating the lip that forms when standard cuffs are deflated.

30 CFR 7.23 - Application requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.23 Application requirements. (a) Brattice cloth. A single application may address two or more...

30 CFR 7.23 - Application requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.23 Application requirements. (a) Brattice cloth. A single application may address two or more...

30 CFR 7.23 - Application requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth and Ventilation Tubing § 7.23 Application requirements. (a) Brattice cloth. A single application may address two or more...

[A new applicator with regulatable air bag designed for intracavitary brachytherapy of nasopharyngeal carcinoma].

PubMed

Zhang, Ning; Wei, Guang-Yu; Tan, Yi-Chang; Huang, Ze-Li; Li, Shao-En; Lu, Zhi-Qian

2004-10-01

Nasopharynx applicator used in intracavitary brachytherapy plays an important role in the radiotherapy of nasopharyngeal carcinoma (NPC), its quality affects the efficiency of treatment. This study was to design a new applicator for clinical use. An inexpensive, reusable, and flexible latex nasopharynx applicator was designed. An air bag was placed at 15 mm from the foreside of the applicator, clung to the tube. The edge of air bag is tangent to the axis of tube. When the bag was full of air, the tube would hunch reversely,close to nasopharyngeal vault. After introduced into nasopharynx through middle nasal meatus, the applicator could be fixed in suitable position by its rotation, and air bag regulation, and confirmed its position by simulation. A total of 221 patients with NPC were treated with external beam radiation therapy in our hospital, and boosted HDR brachytherapy using this new applicator. The response rate was 92.6% in the primary tumor group (200/216), and 100% in the recurrent tumor group (5/5). Mucosal necrosis in the posterior or anterior wall of nasopharynx occurred in 5 patients, 8 patients experienced nasal congestion and nasal synechia. This new nasopharynx applicator is easy to operate, painless, and well dosage-distributed. Mucosal necrosis is likely due to higher fractional dose.

Translation, validation and cultural adaptation of "The Eustachian Tube Dysfunction Questionnaire-7" (ETDQ-7) to Brazilian Portuguese (BR).

PubMed

Gallardo, Fernanda Pires; Onishi, Ektor Tsuneo; Lira, Francisco Iure; Suzuki, Flávia Barros; Testa, José Ricardo Gurgel

2018-04-19

Chronic Eustachian tube dysfunction can cause several symptoms and middle ear conditions that can impact patient quality of life. It is estimated to be relatively frequent, affecting approximately 5% of adults. The diagnostic tools for this condition are still inadequate. In 2012, McCoul et al. published a questionnaire for the evaluation of Eustachian tube dysfunction named ETDQ-7. They established its replicability and validity. The cutoff point for the diagnosis of chronic Eustachian tube dysfunction was equal to or greater than 14.5, with 100% sensitivity and 100% specificity. To translate, adapt and validate the ETDQ-7 questionnaire to Brazilian Portuguese. We translated the questionnaire into Brazilian Portuguese and applied it to 50 patients, 20 of whom had chronic Eustachian tube dysfunction, and 30 controls. The results obtained with the North-American questionnaire were confirmed in its Brazilian version. The cut-off point for the diagnosis of chronic Eustachian tube dysfunction was ≥14, also exhibiting high sensitivity and specificity, very similar to that of ETDQ-7. It is recommended that ETDQ-7 be used to complement the clinical history of patients with chronic Eustachian tube dysfunction; it can also be used as an important tool for diagnosis, patient follow-up and treatment management. Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

[Optimal beam quality for chest digital radiography].

PubMed

Oda, Nobuhiro; Tabata, Yoshito; Nakano, Tsutomu

2014-11-01

To investigate the optimal beam quality for chest computed radiography (CR), we measured the radiographic contrast and evaluated the image quality of chest CR using various X-ray tube voltages. The contrast between lung and rib or heart increased on CR images obtained by lowering the tube voltage from 140 to 60 kV, but the degree of increase was less. Scattered radiation was reduced on CR images with a lower tube voltage. The Wiener spectrum of CR images with a low tube voltage showed a low value under identical conditions of amount of light stimulated emission. The quality of chest CR images obtained using a lower tube voltage (80 kV and 100 kV) was evaluated as being superior to those obtained with a higher tube voltage (120 kV and 140 kV). Considering the problem of tube loading and exposure in clinical applications, a tube voltage of 90 to 100 kV (0.1 mm copper filter backed by 0.5 mm aluminum) is recommended for chest CR.

Raytheon Advanced Miniature Cryocooler Characterization Testing

NASA Astrophysics Data System (ADS)

Conrad, T.; Yates, R.; Schaefer, B.; Bellis, L.; Pillar, M.; Barr, M.

2015-12-01

The Raytheon Advanced Miniature (RAM) cryocooler is a flight packaged, high frequency pulse tube cooler with an integrated surge volume and inertance tube. Its design has been fully optimized to make use of the Raytheon Advanced Regenerator, resulting in improved efficiency relative to previous Raytheon pulse tube coolers. In this paper, thermodynamic characterization data for the RAM cryocooler is presented along with details of its design specifications.

An Inexpensive and Versatile Version of Kundt's Tube for Measuring the Speed of Sound in Air

ERIC Educational Resources Information Center

Papacosta, Pangratios; Linscheid, Nathan

2016-01-01

Experiments that measure the speed of sound in air are common in high schools and colleges. In the Kundt's tube experiment, a horizontal air column is adjusted until a resonance mode is achieved for a specific frequency of sound. When this happens, the cork dust in the tube is disturbed at the displacement antinode regions. The location of the…

YouTube as an information source for pediatric adenotonsillectomy and ear tube surgery.

PubMed

Sorensen, Jeffrey A; Pusz, Max D; Brietzke, Scott E

2014-01-01

Assess the overall quality of information on adenotonsillectomy and ear tube surgery presented on YouTube (www.youtube.com) from the perspective of a parent or patient searching for information on surgery. The YouTube website was systematically searched on select dates with a formal search strategy to identify videos pertaining to pediatric adenotonsillectomy and ear tube surgery. Only videos with at least 5 (ear tube surgery) or 10 (adenotonsillectomy) views per day were included. Each video was viewed and scored by two independent scorers. Videos were categorized by goal and scored for video/audio quality, accuracy, comprehensiveness, and procedure-specific content. Cross-sectional study. Public domain website. Fifty-five videos were scored for adenotonsillectomy and forty-seven for ear tube surgery. The most common category was educational (65.3%) followed by testimonial (28.4%), and news program (9.8%). Testimonials were more common for adenotonsillectomy than ear tube surgery (41.8% vs. 12.8%, p=0.001). Testimonials had a significantly lower mean accuracy (2.23 vs. 2.62, p=0.02), comprehensiveness (1.71 vs. 2.22, p=0.007), and TA specific content (0.64 vs. 1.69, p=0.001) score than educational type videos. Only six videos (5.9%) received high scores in both video/audio quality and accuracy/comprehensiveness of content. There was no significant association between the accuracy and comprehensive score and views, posted "likes", posted "dislikes", and likes/dislikes ratio. There was an association between "likes" and mean video quality (Spearman's rho=0.262, p=0.008). Parents/patients searching YouTube for information on pediatric adenotonsillectomy and ear tube surgery will generally encounter low quality information with testimonials being common but of significantly lower quality. Viewer perceived quality ("likes") did not correlate to formally scored content quality. Published by Elsevier Ireland Ltd.

Draft standard for color AMLCDs in U.S. military aircraft

NASA Astrophysics Data System (ADS)

Hopper, Darrel G.; Dolezal, William K.; Schur, Keith; Liccione, John W.

1994-06-01

Flight instruments have begun to use color active liquid crystal displays (AMLCDs), signaling the beginning of a significant transition from electromechanical and cathode ray tube display designs to AMLCD designs. We have the opportunity with this new technology to establish common products capable of meeting user requirements for sunlight-readable, color and gray scale-capable, high-pixel-count, flat-panel displays for weapon systems. The Wright Laboratory is leading the development of standard and specification documentation for this new generation of display modules based on requirements for U.S. military aircraft. These requirements are similar in many ways to those of both the civil aviation and automotive industries. Accordingly, commonality with these applications is incorporated, where possible, along with the requirements for all military combat applications. Industry and government organizations are involved in this process through workshops and draft review processes. Military procurement specifications for combat system applications may use this information as a source of recommended best practice for this new generation of digital flat panel displays. The draft standard will be revised based upon continuing feedback by early 1995.

Gastroenteric tube feeding: Techniques, problems and solutions

PubMed Central

Blumenstein, Irina; Shastri, Yogesh M; Stein, Jürgen

2014-01-01

Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake, chronic neurological or mechanical dysphagia or gut dysfunction, and patients who are critically ill. However, despite the benefits and widespread use of enteral tube feeding, some patients experience complications. This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding, together with associated complications and special aspects. We conducted an extensive literature search on PubMed, Embase and Medline using index terms relating to enteral access, enteral feeding/nutrition, tube feeding, percutaneous endoscopic gastrostomy/jejunostomy, endoscopic nasoenteric tube, nasogastric tube, and refeeding syndrome. The literature showed common routes of enteral access to include nasoenteral tube, gastrostomy and jejunostomy, while complications fall into four major categories: mechanical, e.g., tube blockage or removal; gastrointestinal, e.g., diarrhea; infectious e.g., aspiration pneumonia, tube site infection; and metabolic, e.g., refeeding syndrome, hyperglycemia. Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route, gastrointestinal complications are without doubt the most common. Complications associated with enteral tube feeding can be reduced by careful observance of guidelines, including those related to food composition, administration rate, portion size, food temperature and patient supervision. PMID:25024606

Conceptual design and structural analysis for an 8.4-m telescope

NASA Astrophysics Data System (ADS)

Mendoza, Manuel; Farah, Alejandro; Ruiz Schneider, Elfego

2004-09-01

This paper describes the conceptual design of the optics support structures of a telescope with a primary mirror of 8.4 m, the same size as a Large Binocular Telescope (LBT) primary mirror. The design goal is to achieve a structure for supporting the primary and secondary mirrors and keeping them joined as rigid as possible. With this purpose an optimization with several models was done. This iterative design process includes: specifications development, concepts generation and evaluation. Process included Finite Element Analysis (FEA) as well as other analytical calculations. Quality Function Deployment (QFD) matrix was used to obtain telescope tube and spider specifications. Eight spiders and eleven tubes geometric concepts were proposed. They were compared in decision matrixes using performance indicators and parameters. Tubes and spiders went under an iterative optimization process. The best tubes and spiders concepts were assembled together. All assemblies were compared and ranked according to their performance.

Nonlinear acoustic streaming in straight and tapered tubes

NASA Astrophysics Data System (ADS)

Tuttle, Brian C.

In thermoacoustic and Stirling devices such as the pulse-tube refrigerator, efficiency is diminished by the formation of a second-order mean velocity known as Rayleigh streaming. This flow emerges from the interaction of the working gas with the wall of the tube in a thin boundary layer. Recent studies have suggested that streaming velocity can be decreased in a tube by tapering it slightly. This research investigates that claim through the development of a numerical model of Rayleigh streaming in variously tapered tubes. It is found that the numerical simulation of streaming in a straight tube compares well with theory, and the application of different thermal boundary conditions at the tube wall shows that for pressurized helium, inner streaming vortices which appear near an adiabatic tube wall do not develop near an isothermal wall. An order analysis indicates that the temperature dependence of viscosity and thermal conductivity contributes appreciably to an accurate numerical model of streaming. Comparison of Rayleigh streaming in tapered tubes shows the effects of taper angle on the circulation and velocity of the mean flow.

Packed in-tube solid phase microextraction with graphene oxide supported on aminopropyl silica: Determination of target triazines in water samples.

PubMed

De Toffoli, Ana L; Fumes, Bruno H; Lanças, Fernando M

2018-02-22

On-line in-tube solid phase microextraction (in-tube SPME) coupled to high performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS) was successfully applied to the determination of selected triazines in water samples. The method based on the employment of a packed column containing graphene oxide (GO) supported on aminopropyl silica (Si) showed that the extraction phase has a high potential for triazines extraction aiming to its physical-chemical properties including ultrahigh specific surface area, good mechanical and thermal stability and high fracture strength. Injection volume and loading time were both investigated and optimized. The method validation using Si-GO to extract and concentrate the analytes showed satisfactory results, good sensitivity, good linearity (0.2-4.0 µg L -1 ) and low detection limits (1.1-2.9 ng L -1 ). The high extraction efficiency was determined with enrichment factors ranging from 1.2-2.9 for the lowest level, 1.3-4.9 intermediate level and 1.2-3.0 highest level (n = 3). Although the analytes were not detected in the real samples evaluated, the method has demonstrated to be efficient through its application in the analysis of spiked triazines in ground and mineral water samples.

Direct simulation of electroosmosis around a spherical particle with inhomogeneously acquired surface charge.

PubMed

Alizadeh, Amer; Wang, Moran

2017-03-01

Uncovering electroosmosis around an inhomogeneously acquired charge spherical particle in a confined space could provide detailed insights into its broad applications from biology to geology. In the present study, we developed a direct simulation method with the effects of inhomogeneously acquired charges on the particle surface considered, which has been validated by the available analytical and experimental data. Modeling results reveal that the surface charge and zeta potential, which are acquired through chemical interactions, strongly depend on the local solution properties and the particle size. The surface charge and zeta potential of the particle would significantly vary with the tangential positions on the particle surface by increasing the particle radius. Moreover, regarding the streaming potential for a particle-fluid tube system, our results uncover that the streaming potential has a reverse relation with the particle size in a micro or nanotube. To explain this phenomenon, we present a simple relation that bridges the streaming potential with the particle size and tube radius, zeta potential, bulk and surface conductivity. This relation could predict good results specifically for higher ion concentrations and provide deeper understanding of the particle size effects on the streaming potential measurements of the particle fluid tube system. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermally induced stresses and deformations in angle-ply composite tubes

NASA Technical Reports Server (NTRS)

Hyer, M. W.; Rousseau, Carl Q.

1987-01-01

Cure-induced uniform temperature change effects on the stresses, axial expansion, and thermally-induced twist of four specific angle-ply tube designs are discussed with a view to the tubes' use as major space structure components. The stresses and deformations in the tubes are studied as a function of the four designs, the off-axis angle, and the single-material and hybrid reinforcing-material construction used. It is found that tube design has a minor influence on the stresses, axial stiffness, and axial thermal expansion characteristics, which are more directly a function of off-axis angle and material selection; tube design is, however, the primary influence in the definition of thermally-induced twist and torsional stiffness characteristics. None of the designs is free of thermally induced twist.

Lunar Lava Tube Sensing

NASA Technical Reports Server (NTRS)

York, Cheryl Lynn; Walden, Bryce; Billings, Thomas L.; Reeder, P. Douglas

1992-01-01

Large (greater than 300 m diameter) lava tube caverns appear to exist on the Moon and could provide substantial safety and cost benefits for lunar bases. Over 40 m of basalt and regolith constitute the lava tube roof and would protect both construction and operations. Constant temperatures of -20 C reduce thermal stress on structures and machines. Base designs need not incorporate heavy shielding, so lightweight materials can be used and construction can be expedited. Identification and characterization of lava tube caverns can be incorporated into current precursor lunar mission plans. Some searches can even be done from Earth. Specific recommendations for lunar lava tube search and exploration are (1) an Earth-based radar interferometer, (2) an Earth-penetrating radar (EPR) orbiter, (3) kinetic penetrators for lunar lava tube confirmation, (4) a 'Moon Bat' hovering rocket vehicle, and (5) the use of other proposed landers and orbiters to help find lunar lava tubes.

Dynamics of Magnetic Flux Tubes in an Advective Flow around a Black Hole

NASA Astrophysics Data System (ADS)

Deb, Arnab; Chakrabarti, Sandip Kumar; Giri, Kinsuk

2016-07-01

Magnetic fields cannibalized by an accretion flow would very soon have a dominant toroidal component. Without changing the topology, we study the movements of these flux tubes inside a geometrically thick advective disk which undergo centrifugal pressure supported shocks. We also consider the effects of the flux tubes on the flow. We use a finite element method (Total Variation Diminishing) for this purpose and specifically focussed whether the flux tubes contribute to changes in outflow properties in terms of its collimation and outflow rates. It is seen that depending upon the cross sectional radius of the flux tubes (which control the drag force), these field lines may move towards the central object or oscillate vertically before eventually escaping out of the funnel wall (pressure zero surface). These interesting results obtained with and without flux tubes point to the role the flux tubes play in collimation of jets and outflows.

Effects of Fuel Distribution on Detonation Tube Performance

NASA Technical Reports Server (NTRS)

Perkins, H. Douglas; Sung, Chih-Jen

2003-01-01

A pulse detonation engine uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Uniform mixing is commonly assumed when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform Hz/air mixtures were analyzed using a two-dimensional Navier-Stokes computational fluid dynamics code with detailed chemistry. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios were studied; one stoichiometric, one fuel lean, and one fuel rich. All mixtures were detonable throughout the detonation tube. Various mixtures representing the same average test section equivalence ratio were shown to have specific impulses within 1% of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance under conditions investigated.

SIPP, a Novel Mitochondrial Phosphate Carrier, Mediates in Self-Incompatibility1[OPEN

PubMed Central

2017-01-01

In Solanaceae, the S-specific interaction between the pistil S-RNase and the pollen S-Locus F-box protein controls self-incompatibility (SI). Although this interaction defines the specificity of the pollen rejection response, the identification of three pistil essential modifier genes unlinked to the S-locus (HT-B, 120K, and NaStEP) unveils a higher degree of complexity in the pollen rejection pathway. We showed previously that NaStEP, a stigma protein with homology with Kunitz-type protease inhibitors, is essential to SI in Nicotiana spp. During pollination, NaStEP is taken up by pollen tubes, where potential interactions with pollen tube proteins might underlie its function. Here, we identified NaSIPP, a mitochondrial protein with phosphate transporter activity, as a novel NaStEP-interacting protein. Coexpression of NaStEP and NaSIPP in pollen tubes showed interaction in the mitochondria, although when expressed alone, NaStEP remains mostly cytosolic, implicating NaSIPP-mediated translocation of NaStEP into the organelle. The NaSIPP transcript is detected specifically in mature pollen of Nicotiana spp.; however, in self-compatible plants, this gene has accumulated mutations, so its coding region is unlikely to produce a functional protein. RNA interference suppression of NaSIPP in Nicotiana spp. pollen grains disrupts the SI by preventing pollen tube inhibition. Taken together, our results are consistent with a model whereby the NaStEP and NaSIPP interaction, in incompatible pollen tubes, might destabilize the mitochondria and contribute to arrest pollen tube growth. PMID:28874520

Closed-Tube Barcoding.

PubMed

Sirianni, Nicky M; Yuan, Huijun; Rice, John E; Kaufman, Ronit S; Deng, John; Fulton, Chandler; Wangh, Lawrence J

2016-11-01

Here, we present a new approach for increasing the rate and lowering the cost of identifying, cataloging, and monitoring global biodiversity. These advances, which we call Closed-Tube Barcoding, are one application of a suite of proven PCR-based technologies invented in our laboratory. Closed-Tube Barcoding builds on and aims to enhance the profoundly important efforts of the International Barcode of Life initiative. Closed-Tube Barcoding promises to be particularly useful when large numbers of small or rare specimens need to be screened and characterized at an affordable price. This approach is also well suited for automation and for use in portable devices.

Numerical simulation of fluid flow and heat transfer in enhanced copper tube

NASA Astrophysics Data System (ADS)

Rahman, M. M.; Zhen, T.; Kadir, A. K.

2013-06-01

Inner grooved tube is enhanced with grooves by increasing the inner surface area. Due to its high efficiency of heat transfer, it is used widely in power generation, air conditioning and many other applications. Heat exchanger is one of the example that uses inner grooved tube to enhance rate heat transfer. Precision in production of inner grooved copper tube is very important because it affects the tube's performance due to various tube parameters. Therefore, it is necessary to carry out analysis in optimizing tube performance prior to production in order to avoid unnecessary loss. The analysis can be carried out either through experimentation or numerical simulation. However, experimental study is too costly and takes longer time in gathering necessary information. Therefore, numerical simulation is conducted instead of experimental research. Firstly, the model of inner grooved tube was generated using SOLIDWORKS. Then it was imported into GAMBIT for healing, followed by meshing, boundary types and zones settings. Next, simulation was done in FLUENT where all the boundary conditions are set. The simulation results were observed and compared with published experimental results. It showed that heat transfer enhancement in range of 649.66% to 917.22% of inner grooved tube compared to plain tube.

Improvements in opti-chromic dosimeters for radiation processing

NASA Astrophysics Data System (ADS)

Humpherys, K. C.; Kantz, A. D.

"Opti-Chromic" dosimeters consisting of radiachromic dye in flourinated polymer tubing have been introduced as a dosimetry system in the range from 10 1 to 5 × 10 4 Gy. Batches of "Opti-Chromic" dosimeters have been produced to evaluate performance under large scale industrial conditions. A systematic study was undertaken to determine the effect of various dosimeter parameters on radiation sensitivity, shelf life, and response characteristics at the higher absorbed doses. These parameters were (A) Type of flourinated polymer tubing; (B) Organic solvent used to activate the radiachromic dye; (C) Concentration of radiachromic dye; (D) Additives to provide proper viscosity, color stability, and high-dose response. Prototype batches were produced and experimental dosimeters exposed to a range of absorbed doses and the response measured as a function of shelf life and dose. The results of the study are presented, and an improved formulation recommended for application to Food Processing. Other formulations may be of value in specific requirements of sensitivity or temperature.

Numerical investigation of heat transfer in annulus laminar flow of multi tubes-in-tube helical coil

NASA Astrophysics Data System (ADS)

Nada, S. A.; Elattar, H. F.; Fouda, A.; Refaey, H. A.

2018-03-01

In the present study, a CFD analysis using ANSYS-FLUENT 14.5 CFD package is used to investigate the characteristics of heat transfer of laminar flow in annulus formed by multi tubes in tube helically coiled heat exchanger. The numerical results are validated by comparison with previous experimental data and fair agreements were existed. The influences of the design and operation parameters such as heat flux, Reynolds numbers and annulus geometry on the heat transfer characteristics are investigated. Different annulus of different numbers of inner tubes, specifically 1, 2, 3, 4 and 5 tubes, are tested. The Results showed that for all the studied annulus, the heat flux has no effect on the Nusselt number and compactness parameter. The annulus formed by using five inner tubes showed the best heat transfer performance and compactness parameter. Correlation of predicting Nusselt number in terms of Reynolds number and number of inner tubes are presented.

Single crystal growth of submillimeter diameter sapphire tube by the micro-pulling down method

NASA Astrophysics Data System (ADS)

Kamada, Kei; Murakami, Rikito; Kochurikhin, Vladimir V.; Luidmila, Gushchina; Jin Kim, Kyoung; Shoji, Yasuhiro; Yamaji, Akihiro; Kurosawa, Shunsuke; Ohashi, Yuji; Yokota, Yuui; Yoshikawa, Akira

2018-06-01

This paper addresses several aspects of the μ-PD growth technology as applied to submillimeter diameter sapphire tubes for UFD application. The μ-PD method has been successfully adapted for single crystal sapphire tube growth. A compound crucible made possible the growth of single crystal sapphire tube as small as around 0.70-0.72 mm in outer diameter and 0.28-0.29 in inner diameter over 160 mm in length at growth rate of 2-4 mm/min along 〈0 0 1〉 direction. An Ir crucible with a die composed of an equivalent hole and Ir wire was heated by RF coil in N2 atmosphere. The μ-PD method has been successfully adapted for single crystal sapphire tube growth. Grown crystal tube showed good XRC value of 30.2 arcsec.

Note: A table-top blast driven shock tube

NASA Astrophysics Data System (ADS)

Courtney, Michael W.; Courtney, Amy C.

2010-12-01

The prevalence of blast-induced traumatic brain injury in conflicts in Iraq and Afghanistan has motivated laboratory scale experiments on biomedical effects of blast waves and studies of blast wave transmission properties of various materials in hopes of improving armor design to mitigate these injuries. This paper describes the design and performance of a table-top shock tube that is more convenient and widely accessible than traditional compression driven and blast driven shock tubes. The design is simple: it is an explosive driven shock tube employing a rifle primer that explodes when impacted by the firing pin. The firearm barrel acts as the shock tube, and the shock wave emerges from the muzzle. The small size of this shock tube can facilitate localized application of a blast wave to a subject, tissue, or material under test.

A Role for YouTube in Telerehabilitation

PubMed Central

Manasco, M. Hunter; Barone, Nicholas; Brown, Amanda

2010-01-01

YouTube (http://youtube.com) is a free video sharing website that allows users to post and view videos. Although there are definite limitations in the applicability of this website to telerehabilitation, the YouTube technology offers potential uses that should not be overlooked. For example, some types of therapy, such as errorless learning therapy for certain language and cognitive deficits can be provided remotely via YouTube. In addition, the website’s social networking capabilities, via the asynchronous posting of comments and videos in response to posted videos, enables individuals to gain valuable emotional support by communicating with others with similar health and rehabilitation challenges. This article addresses the benefits and limitations of YouTube in the context of telerehabilitation and reports patient feedback on errorless learning therapy for aphasia delivered via videos posted on YouTube. PMID:25945173

Note: A table-top blast driven shock tube.

PubMed

Courtney, Michael W; Courtney, Amy C

2010-12-01

The prevalence of blast-induced traumatic brain injury in conflicts in Iraq and Afghanistan has motivated laboratory scale experiments on biomedical effects of blast waves and studies of blast wave transmission properties of various materials in hopes of improving armor design to mitigate these injuries. This paper describes the design and performance of a table-top shock tube that is more convenient and widely accessible than traditional compression driven and blast driven shock tubes. The design is simple: it is an explosive driven shock tube employing a rifle primer that explodes when impacted by the firing pin. The firearm barrel acts as the shock tube, and the shock wave emerges from the muzzle. The small size of this shock tube can facilitate localized application of a blast wave to a subject, tissue, or material under test.

Influence of Regenerator Material on Performance of a 6K High Frequency Pulse Tube Cryocooler

NASA Astrophysics Data System (ADS)

J, Quan; YJ, Liu; XY, Li; JT, Liang

2017-12-01

As very low temperature high frequency pulse tube cryocooler has been a hot topic in the field of pulse tube cryocooler, improving the cryocooler’s performance is a common goal of researchers. By integrating the former results, we found that regenerator material is a key factor for the improvement of pulse tube cryocooler’s efficiency. In this paper, methods of simulation and experiment were used to investigate the influence of stacking style on performance of 6K high frequency pulse tube cryocooler. Finally, the lowest temperature has dropped from 8.8K to 6.7K and more than 10mW of cooling power is achieved at 8K with a two-stage thermally coupled high frequency pulse tube cryocooler. The results make the space application of NbN terahertz detectors possible.

Vortex tube can increase liquid hydrocarbon recovery at plant inlet

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

Hajdik, B.; Lorey, M.; Steinle, J.

1997-09-08

Use of a vortex-tube device yields improved inlet gas-liquid separation, when compared with a Joule-Thomson system, but is less costly and complex than a true isentropic system, such as a turboexpander. Because the vortex-tube unit provides separation as well as pressure reduction, the capital cost of a Joule-Thomson system with valve and separator will be similar to that of the vortex-tube system. Future applications of vortex-tube units will be concentrated where performance improvements over Joule-Thomson units, at low capital cost, are required. The operating characteristics of a vortex tube permit gas, in part, to be reduced in temperature to lessmore » than that normally achievable through isenthalpic expansion. The following three examples show how vortex technology can be applied to achieve these aims.« less

Pathobiology and genetics of neural tube defects.

PubMed

Finnell, Richard H; Gould, Amy; Spiegelstein, Ofer

2003-01-01

Neural tube defects (NTDs), including spina bifida and anencephaly, are common congenital malformations that occur when the neural tube fails to achieve proper closure during early embryogenesis. Based on epidemiological and clinical data obtained over the last few decades, it is apparent that these multifactorial defects have a significant genetic component to their etiology that interacts with specific environmental risk factors. The purpose of this review article is to synthesize the existing literature on the genetic factors contributing to NTD risk. To date, there is evidence that closure of the mammalian neural tube initiates and fuses intermittently at four discrete locations. Disruption of this process at any of these four sites may lead to an NTD, possibly arising through closure site-specific genetic mechanisms. Candidate genes involved in neural tube closure include genes of the folate metabolic pathway, as well as those involved in folate transport. Although extensive efforts have focused on elucidating the genetic risk factors contributing to the etiology of NTDs, the population burden for these malformations remains unknown. One group at high risk for having children with NTDs is epileptic women receiving antiepileptic medications during pregnancy. Efforts to better understand the genetic factors that may contribute to their heightened risk, as well as the pathogenesis of neural tube closure defects, are reviewed herein.

Transcriptome analysis of tube foot and large scale marker discovery in sea cucumber, Apostichopus japonicus.

PubMed

Zhou, Xiaoxu; Wang, Hongdi; Cui, Jun; Qiu, Xuemei; Chang, Yaqing; Wang, Xiuli

2016-12-01

Tube foot as one of the ambulacral appendages types in Aspidochirote holothurioids, is known for their functions in locomotion, feeding, chemoreception, light sensitivity and respiration. In this study, we explored the characteristic of transcriptome in the tube foot of sea cucumber (Apostichopus japonicus). Our results showed that among 390 unigenes which specifically expressed in the tube foot, 190 of them were annotated. Based on the assembly transcriptome, we found 219,860 SNPs from 34,749 unigenes, 97,683, 53,624, 27,767 and 40,786 were located in CDSs, 5'-UTRs, 3'-UTRs and non-CDS separately. Furthermore, 12,114 SSRs were detected from 7394 unigenes. Target genes of four specifically expressed miRNAs (miR-29a, miR-29b, miR-278-3p and miR-2005) in tube foot were also predicted based on the transcriptome, which contain immune-related factors (MBL, VLRA, AjC3, MyD88, CFB), skin pigmentation (MITF), candidate regeneration factor (TRP) and holothurians autolysis-related factor (CL). These results develop a relatively large number of molecular markers and transcriptome resources, and will provide a foundation for further analyses on the function and molecular mechanisms underlying A. japonicas tube foot. Copyright © 2016 Elsevier Inc. All rights reserved.

40 CFR 469.30 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ELECTRICAL AND ELECTRONIC COMPONENTS POINT SOURCE CATEGORY Cathode Ray Tube Subcategory § 469.30 Applicability. (a) The provisions of this subpart are applicable to discharges resulting from the manufacture of...

Falope ring tubal sterilization through suprapubic minilaparotomy approach.

PubMed

Apichart, N

1981-12-01

A series of 146 cases of interval female tubal sterilization using a Falope Ring through suprapubic minilaparotomy approach performed at Patpong clinic in Bangkok from December 1977-November 1978 is reported. Pomeroy's method has long been the most popular sterilization procedure but in this method the length of the knuckle of the tube being occluded and the site of occlusion is variable depending on the individual surgeon's preference. Tubal occlusion using silicone rubber band has the advantage that the knuckle of the tube being occluded always contains the same length of fallopian tube and the tube is always occluded at the isthmus portion. The combination of Falope Ring tubal occlusion and suprapubic minilaparotomy is a new approach for interval female sterilization. Ages of the group studied ranged from 20-45 years, 71.9% had 2-3 children, 38.4% had had one abortion, 50% had had a live birth as the outcome of their last pregnancy, 69% had used oral contraceptives. The acceptor, the author states, must have a preoperative physical checkup and laboratory tests including a complete blood count and urinalysis. The procedure is then performed; procedural steps of Falope Ring application are presented. Oral Glatenine and Diazepam have been used before the procedure. Tubal transection occurred in about 2.5% of the reported series; proper ring application technique and avoidance of application to the inflamed tube would reduce this potential complication. Some degree of difficulty was encountered in 12.3% of the cases. In all except 4 cases Falope rings were applied to both tubes. Questionnaires were sent to the women 3, 6, and 12 months after sterilization; no pregnancies were reported.

Experiment attributes to establish tube with twisted tape insert performance cooling plasma facing components

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

Clark, Emily; Ramirez, Emilio; Ruggles, Art E.

The modeling capability for tubes with twisted tape inserts is reviewed with reference to the application of cooling plasma facing components in magnetic confinement fusion devices. The history of experiments examining the cooling performance of tubes with twisted tape inserts is reviewed with emphasis on the manner of heating, flow stability limits and the details of the test section and fluid delivery system. Models for heat transfer, burnout, and onset of net vapor generation in straight tube flows and tube with twisted tape are compared. As a result, the gaps in knowledge required to establish performance limits of the plasmamore » facing components are identified and attributes of an experiment to close those gaps are presented.« less

Study of foldable elastic tubes for large space structure applications, phase 3

NASA Technical Reports Server (NTRS)

Jones, I. W.; Mitchell, S. O.

1981-01-01

A bi-convex foldable elastic tube, suitable for use in self deploying space structures, was subjected to a series of buckling tests to deterine initial buckling loads, collapse loads, and the buckling mode. The tube is cylindrical with a cross-section that is lenticular-like with flared edges. It is capable of being flattened in the center and folded compactly, storing up strain energy in the process. Upon removal of constraint, it springs back to its original straight configuration, releasing the stored strain energy. The tests showed that this type of tube has good resistance to buckling, with the initial buckling loads all falling within or above the range of those for comparable circular cylindrical tubes.

Experiment attributes to establish tube with twisted tape insert performance cooling plasma facing components

DOE PAGES

Clark, Emily; Ramirez, Emilio; Ruggles, Art E.; ...

2015-08-18

The modeling capability for tubes with twisted tape inserts is reviewed with reference to the application of cooling plasma facing components in magnetic confinement fusion devices. The history of experiments examining the cooling performance of tubes with twisted tape inserts is reviewed with emphasis on the manner of heating, flow stability limits and the details of the test section and fluid delivery system. Models for heat transfer, burnout, and onset of net vapor generation in straight tube flows and tube with twisted tape are compared. As a result, the gaps in knowledge required to establish performance limits of the plasmamore » facing components are identified and attributes of an experiment to close those gaps are presented.« less

Ultrasonic probe for inspecting double-wall tube. [Patent application

DOEpatents

Cook, K.V.; Cunningham, R.A. Jr.; Murrin, H.T.

1981-05-29

An ultrasonic probe for inspecting the interface between the walls of a double-wall tube comprises a cylindrical body member having two cavities axially spaced apart thereon. The probe is placed in the tube and ultrasonic energy is transmitted from a transducer in its body member to a reflector in one of its cavities and thence into the inner wall of the tube. A second transducer in the probe body member communicates with the second cavity through a collimation passage in the body member, and the amount of ultrasonic energy reflected from the interface between the walls of the tube to a second reflector through the collimation passage to the second transducer depends upon the characteristics of said interface.

Nondestructive testing of moisture separator reheater tubing system using Hall sensor array

NASA Astrophysics Data System (ADS)

Le, Minhhuy; Kim, Jungmin; Kim, Jisoo; Do, Hwa Sik; Lee, Jinyi

2018-01-01

This paper presents a nondestructive testing system for inspecting the moisture separator reheater (MSR) tubing system in a nuclear power plant. The technique is based on partial saturation eddy current testing in which a Hall sensor array is used to measure the radial component of the electromagnetic field distributed in the tubes. A finned MRS tube of ferritic stainless steel (SS439) with artificial, flat-bottom hole-type defects was used in the experiments. The results show that the proposed system has potential applications in the MSR system or ferromagnetic material tubes in general, which could detect the artificial defects of about 20% of the wall thickness (0.24 mm). Furthermore, the defect volume could be quantitatively evaluated.

New uses of position-sensitive photomultiplier tubes

NASA Astrophysics Data System (ADS)

Gordon, Jeffrey S.; Redus, Robert H.; Nagarkar, Vivek V.; Squillante, Michael R.

1992-12-01

Recent advances in photomultiplier tube technology have led to the availability of position sensitive photomultiplier tubes (PSPMTs). These tubes make it possible to build a new generation of imaging instruments for gamma rays and other types of ionizing radiation. We have investigated the use of these tubes for the construction of several prototype instruments. The first application investigated measures the quantity and distribution of radioactive compounds on filter papers used in microbiology research. The intent of this instrument is to replace film autoradiography with an electronic imaging system which can analyze samples 75 to 110 times faster than film. The second application involved the development of an intraoperative imaging probe to help surgeons identify cancerous tissue and ensure its complete removal. This instrument will replace a non-imaging probe now in use at many hospitals. A third prototype instrument under evaluation is an imaging nuclear survey system which obtains both a video and gamma ray image for the purpose of locating and quantifying radioactive materials. This system would be used at nuclear power plants and radioactive materials preparation facilities. A modification of this system could be built into robots used for inspecting and repairing power plants.

Shock waves and shock tubes; Proceedings of the Fifteenth International Symposium, Berkeley, CA, July 28-August 2, 1985

NASA Technical Reports Server (NTRS)

Bershader, D. (Editor); Hanson, R. (Editor)

1986-01-01

A detailed survey is presented of shock tube experiments, theoretical developments, and applications being carried out worldwide. The discussions explore shock tube physics and the related chemical, physical and biological science and technology. Extensive attention is devoted to shock wave phenomena in dusty gases and other multiphase and heterogeneous systems, including chemically reactive mixtures. Consideration is given to techniques for measuring, visualizing and theoretically modeling flowfield, shock wave and rarefaction wave characteristics. Numerical modeling is explored in terms of the application of computational fluid dynamics techniques to describing flowfields in shock tubes. Shock interactions and propagation, in both solids, fluids, gases and mixed media are investigated, along with the behavior of shocks in condensed matter. Finally, chemical reactions that are initiated as the result of passage of a shock wave are discussed, together with methods of controlling the evolution of laminar separated flows at concave corners on advanced reentry vehicles.

Shock waves and shock tubes; Proceedings of the Fifteenth International Symposium, Berkeley, CA, July 28-August 2, 1985

NASA Astrophysics Data System (ADS)

Bershader, D.; Hanson, R.

A detailed survey is presented of shock tube experiments, theoretical developments, and applications being carried out worldwide. The discussions explore shock tube physics and the related chemical, physical and biological science and technology. Extensive attention is devoted to shock wave phenomena in dusty gases and other multiphase and heterogeneous systems, including chemically reactive mixtures. Consideration is given to techniques for measuring, visualizing and theoretically modeling flowfield, shock wave and rarefaction wave characteristics. Numerical modeling is explored in terms of the application of computational fluid dynamics techniques to describing flowfields in shock tubes. Shock interactions and propagation, in both solids, fluids, gases and mixed media are investigated, along with the behavior of shocks in condensed matter. Finally, chemical reactions that are initiated as the result of passage of a shock wave are discussed, together with methods of controlling the evolution of laminar separated flows at concave corners on advanced reentry vehicles.

An Evaluation of High Temperature Airframe Seals for Advanced Hypersonic Vehicles

NASA Technical Reports Server (NTRS)

DeMange, Jeffrey J.; Dunlap, Patrick H.; Steinetz, Bruce M.; Drlik, Gary J.

2007-01-01

High temperature seals are required for advanced hypersonic airframe applications. In this study, both spring tube thermal barriers and innovative wafer seal systems were evaluated under relevant hypersonic test conditions (temperatures, pressures, etc.) via high temperature compression testing and room temperature flow assessments. Thermal barriers composed of a Rene 41 spring tube filled with Saffil insulation and overbraided with a Nextel 312 sheath showed acceptable performance at 1500 F in both short term and longer term compression testing. Nextel 440 thermal barriers with Rene 41 spring tubes and Saffil insulation demonstrated good compression performance up to 1750 F. A silicon nitride wafer seal/compression spring system displayed excellent load performance at temperatures as high as 2200 F and exhibited room temperature leakage values that were only 1/3 those for the spring tube rope seals. For all seal candidates evaluated, no significant degradation in leakage resistance was noted after high temperature compression testing. In addition to these tests, a superalloy seal suitable for dynamic seal applications was optimized through finite element techniques.

The effect of cuff presence and cuff inflation on airway pressure in a canine tracheostomy tube model.

PubMed

Wignall, Jamie R; Baines, Stephen J

2014-01-01

To evaluate the effect of cuff presence and cuff inflation on airway pressure in an inspiratory model of canine tracheostomy. Ex vivo experimental study. Cadaver tracheas from Beagle dogs were attached aborally to a vacuum. Airway pressure and flow rate was measured before and after placement of tracheostomy tubes. None. Adult uncuffed tubes and cuffed tracheostomy tubes (sizes 4, 6, 8, and 10) were placed within tracheas. Cuffs were investigated without inflation and at maximum cuff inflation. Airway pressure was measured at constant airflow rates at 30 and 60 L/min. At set flow rates, airway pressures of tracheostomy tubes were compared to the intact trachea. A size 4 uncuffed tracheostomy tube showed the lowest airway pressure and a size 4 cuffed trachestomy tube with inflation showed the highest airway pressures. For sizes 6, 8, and 10 tubes, the presence of a cuff with and without inflation significantly increased airway pressure. Inflation of a cuff always significantly increased airway pressure. Similar pressure is seen between sizes 4 and 6 uncuffed tubes. Cuffed tracheostomy tubes should not be used unless specifically indicated due to increased airway pressure. © Veterinary Emergency and Critical Care Society 2013.

Heat capacity reveals the physics of a frustrated spin tube.

PubMed

Ivanov, Nedko B; Schnack, Jürgen; Schnalle, Roman; Richter, Johannes; Kögerler, Paul; Newton, Graham N; Cronin, Leroy; Oshima, Yugo; Nojiri, Hiroyuki

2010-07-16

We report on theoretical and experimental results concerning the low-temperature specific heat of the frustrated spin-tube material [(CuCl(2)tachH(3)Cl]Cl(2) (tach denotes 1,3,5-triaminocyclohexane). This substance turns out to be an unusually perfect spin-tube system which allows to study the physics of quasi-one-dimensional antiferromagnetic structures in rather general terms. An analysis of the specific-heat data demonstrates that at low enough temperatures the system exhibits a Tomonaga-Luttinger liquid behavior corresponding to an effective spin-3/2 antiferromagnetic Heisenberg chain with short-range exchange interactions. On the other hand, around 2 K the composite spin structure of the chain is revealed through a Schottky-type peak in the specific heat. We argue that the dominating contribution to the peak originates from gapped magnon-type excitations related to the internal degrees of freedom of the rung spins.

Heat Capacity Reveals the Physics of a Frustrated Spin Tube

NASA Astrophysics Data System (ADS)

Ivanov, Nedko B.; Schnack, Jürgen; Schnalle, Roman; Richter, Johannes; Kögerler, Paul; Newton, Graham N.; Cronin, Leroy; Oshima, Yugo; Nojiri, Hiroyuki

2010-07-01

We report on theoretical and experimental results concerning the low-temperature specific heat of the frustrated spin-tube material [(CuCl2tachH)3Cl]Cl2 (tach denotes 1,3,5-triaminocyclohexane). This substance turns out to be an unusually perfect spin-tube system which allows to study the physics of quasi-one-dimensional antiferromagnetic structures in rather general terms. An analysis of the specific-heat data demonstrates that at low enough temperatures the system exhibits a Tomonaga-Luttinger liquid behavior corresponding to an effective spin-3/2 antiferromagnetic Heisenberg chain with short-range exchange interactions. On the other hand, around 2 K the composite spin structure of the chain is revealed through a Schottky-type peak in the specific heat. We argue that the dominating contribution to the peak originates from gapped magnon-type excitations related to the internal degrees of freedom of the rung spins.

Effects of Novel Guidance Tubing Gait on Electromyographic Neuromuscular Imbalance and Joint Angular Kinematics During Locomotion in Hemiparetic Stroke Patients.

PubMed

Lee, Jeong J; You, Joshua Sung H

2017-12-01

To compare the immediate effects of conventional treadmill gait and guidance tubing gait (GTG) on electromyographic neuromuscular imbalance and knee joint kinematics in hemiparetic gait. Case-control study. University medical center. Participants (N=33; 19 men, 14 women) were patients with hemiparetic stroke (n=18 [experimental]; mean age ± SD, 39.2±16.8y) and healthy controls (n=15; mean age ± SD, 26.3±2.6y). The GTG was provided for approximately 30 minutes and involved application of an assistive guidance force using the tubing, specifically to improve knee joint stabilization during midstance and increase knee joint flexion during midswing phase. Clinical tests included the Korean Mini-Mental State Examination, Modified Ashworth Scale, Berg Balance Scale, manual muscle test, and knee joint range of motion and sensory tests. Knee joint muscle electromyographic and kinematic analyses were determined at pretest and posttest. After the intervention, the experimental group showed significantly greater improvements in balanced quadriceps and hamstring electromyographic coactivation and knee joint kinematics relative to the control group (P=.005). The GTG intervention decreased overactive hamstring activity (P=.018) and reciprocally increased quadriceps activity (P<.001). The knee joint kinematic analysis showed significant changes in the hemiparetic stroke group (P=.004). This study demonstrates the effectiveness of the tubing gait condition to restore knee joint muscle imbalance and kinematics in individuals with hemiparetic stroke who present with an abnormal hyperextension knee gait. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Method and system for small scale pumping

DOEpatents

Insepov, Zeke [Darien, IL; Hassanein, Ahmed [Bolingbrook, IL

2010-01-26

The present invention relates generally to the field of small scale pumping and, more specifically, to a method and system for very small scale pumping media through microtubes. One preferred embodiment of the invention generally comprises: method for small scale pumping, comprising the following steps: providing one or more media; providing one or more microtubes, the one or more tubes having a first end and a second end, wherein said first end of one or more tubes is in contact with the media; and creating surface waves on the tubes, wherein at least a portion of the media is pumped through the tube.

Ultrasonic analyte concentration and application in flow cytometry

DOEpatents

Kaduchak, Gregory; Goddard, Greg; Salzman, Gary; Sinha, Dipen; Martin, John C.; Kwiatkowski, Christopher; Graves, Steven

2014-07-22

The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

Ultrasonic analyte concentration and application in flow cytometry

DOEpatents

Kaduchak, Gregory [Los Alamos, NM; Goddard, Greg [Los Alamos, NM; Salzman, Gary [White Rock, NM; Sinha, Dipen [Los Alamos, NM; Martin, John C [Los Alamos, NM; Kwiatkowski, Christopher [Los Alamos, NM; Graves, Steven [San Juan Pueblo, NM

2008-03-11

The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

Ultrasonic analyte concentration and application in flow cytometry

DOEpatents

Kaduchak, Gregory; Goddard, Greg; Salzman, Gary; Sinha, Dipen; Martin, John C.; Kwiatkowski, Christopher; Graves, Steven

2015-07-07

The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

Prototyping of Poly(dimethylsiloxane) Interfaces for Flow Gating, Reagent Mixing, and Tubing Connection in Capillary Electrophoresis

PubMed Central

Zhang, Qiyang; Gong, Maojun

2014-01-01

Integrated microfluidic systems coupled with electrophoretic separations have broad application in biological and chemical analysis. Interfaces for the connection of various functional parts play a major role in the performance of a system. Here we developed a rapid prototyping method to fabricate monolithic poly(dimethylsiloxane) (PDMS) Interfaces for flow-gated injection, online reagent mixing, and tube-to-tube connection in an integrated capillary electrophoresis (CE) system. The basic idea was based on the properties of PDMS: elasticity, transparency, and suitability for prototyping. The molds for these interfaces were prepared by using commercially available stainless steel wires and nylon lines or silica capillaries. A steel wire was inserted through the diameter of a nylon line and a cross format was obtained as the mold for PDMS casting of flow gates and 4-way mixers. These interfaces accommodated tubing connection through PDMS elasticity and provided easy visual trouble shooting. The flow gate used smaller channel diameters thus reducing flow rate by 25 fold for effective gating compared with mechanically machined counterparts. Both PDMS mixers and the tube-to-tube connectors could minimize the sample dead volume by using an appropriate capillary configuration. As a whole, the prototyped PDMS interfaces are reusable, inexpensive, convenient for connection, and robust when integrated with the CE detection system. Therefore, these interfaces could see potential applications in CE and CE-coupled systems. PMID:24331370

Analysis of Tube Hydroforming by means of an Inverse Approach

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

Nguyen, Ba Nghiep; Johnson, Kenneth I.; Khaleel, Mohammad A.

2003-05-01

This paper presents a computational tool for the analysis of freely hydroformed tubes by means of an inverse approach. The formulation of the inverse method developed by Guo et al. is adopted and extended to the tube hydrofoming problems in which the initial geometry is a round tube submitted to hydraulic pressure and axial feed at the tube ends (end-feed). A simple criterion based on a forming limit diagram is used to predict the necking regions in the deformed workpiece. Although the developed computational tool is a stand-alone code, it has been linked to the Marc finite element code formore » meshing and visualization of results. The application of the inverse approach to tube hydroforming is illustrated through the analyses of the aluminum alloy AA6061-T4 seamless tubes under free hydroforming conditions. The results obtained are in good agreement with those issued from a direct incremental approach. However, the computational time in the inverse procedure is much less than that in the incremental method.« less

Manufacturing of tailored tubes with a process integrated heat treatment

NASA Astrophysics Data System (ADS)

Hordych, Illia; Boiarkin, Viacheslav; Rodman, Dmytro; Nürnberger, Florian

2017-10-01

The usage of work-pieces with tailored properties allows for reducing costs and materials. One example are tailored tubes that can be used as end parts e.g. in the automotive industry or in domestic applications as well as semi-finished products for subsequent controlled deformation processes. An innovative technology to manufacture tubes is roll forming with a subsequent inductive heating and adapted quenching to obtain tailored properties in the longitudinal direction. This processing offers a great potential for the production of tubes with a wide range of properties, although this novel approach still requires a suited process design. Based on experimental data, a process simulation is being developed. The simulation shall be suitable for a virtual design of the tubes and allows for gaining a deeper understanding of the required processing. The model proposed shall predict microstructural and mechanical tube properties by considering process parameters, different geometries, batch-related influences etc. A validation is carried out using experimental data of tubes manufactured from various steel grades.

Fluid mechanics and heat transfer spirally fluted tubing

NASA Astrophysics Data System (ADS)

Yampolsky, J. S.; Libby, P. A.; Launder, B. E.; Larue, J. C.

1984-12-01

The objective of this program is to develop an understanding of the fluid mechanics and heat transfer mechanisms that result in the demonstrated performance of the spiral fluted tubing under development at GA Technologies Inc. Particularly emphasized are the processes that result in the augmentation of the heat transfer coefficient without an increase in friction coefficient in the single-phase flow. Quantitative delineation of these processes would allow for their application to the optimal solution of heat transfer problems in general was well as to tubular heat exchanges using spiral fluted tubes. The experimental phase of the program consisted of the following: (1) Flow visualization studies using high-speed photography of dye injected into water flowing in a cast acrylic spiral fluted tube. (2) Time-resolved axial velocity measurements as a function of radius at the exit plane of a spiral fluted tube with water flowing through the tube. (3) Simultaneous time-resolved measurements of the axial and radial velocity components and temperature with heated air flowing through the tube cooled by a water jacket.

Mechanical properties of orthodontic wires covered with a polyether ether ketone tube.

PubMed

Shirakawa, Nobukazu; Iwata, Toshio; Miyake, Shinjiro; Otuka, Takero; Koizumi, So; Kawata, Toshitugu

2018-03-21

To evaluate the esthetics and frictional force of an orthodontic wire passed through a newly designed tube made of a polyether ether ketone (PEEK) resin. Two types of standard PEEK tubes were prepared at 0.5 × 0.6ф and 0.8 × 0.9ф, and different archwires were passed through the tubes. Color values were determined according to brightness and hues. Friction was assessed with different bracket-wire combinations, and surface roughness was determined by stereomicroscopy before and after the application of friction. The PEEK tube showed a color difference that was almost identical to that of coated wires conventionally used in clinical practice, indicating a sufficient esthetic property. The result of the friction test showed that the frictional force was greatly reduced by passing the archwire through the PEEK tube in almost all of the archwires tested. Use of the new PEEK tube demonstrated a good combination of esthetic and functional properties for use in orthodontic appliances.

Preliminary Investigation of the Process Capabilities of Hydroforging

PubMed Central

Alzahrani, Bandar; Ngaile, Gracious

2016-01-01

Hydroforging is a hybrid forming operation whereby a thick tube is formed to a desired geometry by combining forging and hydroforming principles. Through this process hollow structures with high strength-to-weight ratio can be produced for applications in power transmission systems and other structural components that demands high strength-to-weight ratio. In this process, a thick tube is deformed by pressurized fluid contained within the tube using a multi-purpose punch assembly, which is also used to feed tube material into the die cavity. Fluid pressure inside the thick tube is developed by volume change governed by the movement of the punch assembly. In contrast to the conventional tube hydroforming (THF), the hydroforging process presented in this study does not require external supply of pressurized fluid to the deforming tube. To investigate the capability of hydroforging process, an experimental setup was developed and used to hydroforge various geometries. These geometries included hollow flanged vessels, hexagonal flanged parts, and hollow bevel and spur gears. PMID:28787840

The sky blue method as a screening test to detect misplacement of percutaneous endoscopic gastrostomy tube at exchange.

PubMed

Suzuki, Yutaka; Urashima, Mitsuyoshi; Yoshida, Hideki; Iwase, Tsuyoshi; Kura, Toshiroh; Imazato, Shin; Kudo, Michiaki; Ohta, Tomoyuki; Mizuhara, Akihiro; Tamamori, Yutaka; Muramatsu, Hirohito; Nishiguchi, Yukio; Nishiyama, Yorihiro; Takahashi, Mikako; Nishiwaki, Shinji; Matsumoto, Masami; Goshi, Satoshi; Sakamoto, Shigeo; Uchida, Nobuyuki; Ijima, Masashi; Ogawa, Tetsushi; Shimazaki, Makoto; Takei, Shinichi; Kimura, Chikou; Yamashita, Satoyoshi; Endo, Takao; Nakahori, Masato; Itoh, Akihiko; Kusakabe, Toshiro; Ishizuka, Izumi; Iiri, Takao; Fukasawa, Shingo; Arimoto, Yukitsugu; Kajitani, Nobuaki; Ishida, Kazuhiko; Onishi, Koji; Taira, Akihiko; Kobayashi, Makoto; Itano, Yasuto; Kobuke, Toshiya

2009-01-01

During tube exchange for percutaneous endoscopic gastrostomy (PEG), a misplaced tube can cause peritonitis and death. Thus, endoscopic or radiologic observation is required at tube exchange to make sure the tube is placed correctly. However, these procedures cost extensive time and money to perform in all patients at the time of tube exchange. Therefore, we developed the "sky blue method" as a screening test to detect misplacement of the PEG tube during tube exchange. First, sky blue solution consisting of indigocarmine diluted with saline was injected into the gastric space via the old PEG tube just before the tube exchange. Next, the tube was exchanged using a standard method. Then, we checked whether the sky blue solution could be collected through the new tube or not. Finally, we confirmed correct placement of the tube by endoscopic or radiologic observation for all patients. A total of 961 patients were enrolled. Each tube exchange took 1 to 3 minutes, and there were no adverse effects. Four patients experienced a misplaced tube, all of which were detectable with the sky blue method. Diagnostic parameters of the sky blue method were as follows: sensitivity, 94% (95%CI: 92-95%); specificity, 100% (95%CI: 40-100%); positive predictive value, 100% (95%CI: 100-100%); negative predictive value, 6% (95%CI: 2-16%). These results suggest that the number of endoscopic or radiologic observations to confirm correct replacement of the PEG tube may be reduced to one fifteenth using the sky blue method.

MARTINS: A foam/film flow model for molten material relocation in HWRs with U-Al-fueled multi-tube assemblies

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

Kalimullah

1994-03-01

Some special purpose heavy-water reactors (EM) are made of assemblies consisting of a number of coaxial aluminum-clad U-Al alloy fuel tubes and an outer Al sleeve surrounding the fuel tubes. The heavy water coolant flows in the annular gaps between the circular tubes. Analysis of severe accidents in such reactors requires a model for predicting the behavior of the fuel tubes as they melt and disrupt. This paper describes a detailed, mechanistic model for fuel tube heatup, melting, freezing, and molten material relocation, called MARTINS (Melting and Relocation of Tubes in Nuclear subassembly). The paper presents the modeling of themore » phenomena in MARTINS, and an application of the model to analysis of a reactivity insertion accident. Some models are being developed to compute gradual downward relocation of molten material at decay-heat power levels via candling along intact tubes, neglecting coolant vapor hydrodynamic forces on molten material. These models are inadequate for high power accident sequences involving significant hydrodynamic forces. These forces are included in MARTINS.« less

Protective coatings for composite tubes in space applications

NASA Technical Reports Server (NTRS)

Dursch, Harry W.; Hendricks, Carl L.

1987-01-01

Protective coatings for graphite/epoxy (Gr/Ep) tubular structures for a manned Space Station truss structure were evaluated. The success of the composite tube truss structure depends on its stability to long-term exposure to the low earth orbit (LEO) environment, with particular emphasis placed on atomic oxygen. Concepts for protectively coating Gr/Ep tubes include use of inorganic coated metal foils and electroplating. These coatings were applied to Gr/Ep tubes and then subjected to simulated LEO environment to evaluate survivability of coatings and coated tubes. Evaluation included: atomic oxygen resistance, changes in optical properties and adhesion, abrasion resistance, surface preparation required, coating uniformity, and formation of microcracks in the Gr/Ep tubes caused by thermal cycling. Program results demonstrated that both phosphoric and chromic acid anodized Al foil provided excellent adhesion to Gr/Ep tubes and exhibited stable optical properties when subjected to simulated LEO environment. The SiO2/Al coatings sputtered onto Al foils also resulted in an excellent protective coating. Electroplated Ni exhibited unacceptable adhesion loss to Gr/Ep tubes during atomic oxygen exposure.

Protective coatings for composite tubes in space applications

NASA Technical Reports Server (NTRS)

Dursch, Harry W.; Hendricks, Carl L.

1987-01-01

Protective coatings for graphite/epoxy (Gr/Ep) tubular structures for a Manned Space Station truss structure were evaluated. The success of the composite tube truss structure depends on its stability to long-term exposure to the Low Earth Orbit (LEO) environment with particular emphasis placed on atomic oxygen. Concepts for protectively coating Gr/Ep tubes include use of inorganic coated metal foils and electroplating. These coatings were applied to Gr/Ep tubes and then subjected to simulated LEO environmnet to evaluate survivability of coatings and coated tubes. Evaluation included: atomic oxygen resistance, changes in optical properties and adhesion, abrasion resistancem surface preparation required, coating uniformity, and formation of microcracks in the Gr/Ep tubes caused by thermal cycling. Program results demonstrated that both phosphoric and chromic acid anodized Al foil provided excellent adhesion to Gr/Ep tubes and exhibited stable optical properties when subjected to simulated LEO environment. The SiO2/Al coatings speuttered onto Al foils also resulted in an excellent protective coating. Electroplated Ni exhibited unaccepatble adhesion loss to Gr/Ep tubes during atomic oxygen exposure.

Fabrication of fine-grain tantalum diffusion barrier tube for Nb3Sn conductors

NASA Astrophysics Data System (ADS)

Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N.; Robinson, J.; Barber, R. E.

2014-01-01

Diffusion barriers used in Nb3Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy.

a Thermoacoustically-Driven Pulse Tube Cryocryocooler Operating around 300HZ

NASA Astrophysics Data System (ADS)

Yu, G. Y.; Zhu, S. L.; Dai, W.; Luo, E. C.

2008-03-01

High frequency operation of the thermoacoustic cryocooler system, i.e. pulse tube cryocooler driven by thermoacoustic engine, leads to reduced size, which is quite attractive to small-scale cryogenic applications. In this work, a no-load coldhead temperature of 77.8 K is achieved on a 292 Hz pulse tube cryocooler driven by a standing-wave thermoacoustic engine with 3.92 MPa helium gas and 1750 W heat input. To improve thermal efficiency, a high frequency thermoacoustic-Stirling heat engine is also built to drive the same pulse tube cryocooler, and a no-load temperature of 109 K was obtained with 4.38 MPa helium gas, 292 Hz working frequency and 400W heating power. Ideas such as tapered resonators, acoustic amplifier tubes and simple thin tubes without reservoir are used to effectively suppress harmonic modes, amplify the acoustic pressure wave available to the pulse tube cryocooler and provide desired acoustic impedance for the pulse tube cryocooler, respectively. Comparison of systems with different thermoacoustic engines is made. Numerical simulations based on the linear thermoacoustic theory have also been done for comparison with experimental results, which shows reasonable agreement.

SMART Tubing Presents an Increased Risk of Disconnection During Extracorporeal Circulation

PubMed Central

Newling, Ross; Morris, Richard

2005-01-01

Abstract: A number of products exhibiting biocompatible features have been developed for use in extracorporeal blood circuits during cardiopulmonary bypass procedures. While attention has been focused on biocompatibility features of the blood-circuit interface, a number of issues applicable in clinical use of these circuits have arisen. Surface Modifying Additive Technology (SMART; Cobe Cardiovascular, Arvarda, CO) is one such technology. In this product, the structure of normal polyvinylchloride (PVC) tubing is altered through the blending of two copolymers to give a more biocompatible blood to plastic interface. In this study, we examined the in vitro mechanical ability of random samples (n = 10) of SMART and standard PVC tubing to withstand axial tension when the tubing was placed over a single barb of a connector. The tension required to remove the SMART tubing from the connector (83.3 ± 7.3 [SD] N), was significantly less than standard PVC tubing (115.6 ± 15.9 N; p < .0001, unpaired t test). The SMART tubing exhibited a 28% reduction in tubing to connector adhesion, which may have a significant effect on extracorporeal circuit disconnection and overall patient safety. PMID:16524161

Small diameter electrospun silk fibroin vascular grafts: Mechanical properties, in vitro biodegradability, and in vivo biocompatibility.

PubMed

Catto, Valentina; Farè, Silvia; Cattaneo, Irene; Figliuzzi, Marina; Alessandrino, Antonio; Freddi, Giuliano; Remuzzi, Andrea; Tanzi, Maria Cristina

2015-09-01

To overcome the drawbacks of autologous grafts currently used in clinical practice, vascular tissue engineering represents an alternative approach for the replacement of small diameter blood vessels. In the present work, the production and characterization of small diameter tubular matrices (inner diameter (ID)=4.5 and 1.5 mm), obtained by electrospinning (ES) of Bombyx mori silk fibroin (SF), have been considered. ES-SF tubular scaffolds with ID=1.5 mm are original, and can be used as vascular grafts in pediatrics or in hand microsurgery. Axial and circumferential tensile tests on ES-SF tubes showed appropriate properties for the specific application. The burst pressure and the compliance of ES-SF tubes were estimated using the Laplace's law. Specifically, the estimated burst pressure was higher than the physiological pressures and the estimated compliance was similar or higher than that of native rat aorta and Goretex® prosthesis. Enzymatic in vitro degradation tests demonstrated a decrease of order and crystallinity of the SF outer surface as a consequence of the enzyme activity. The in vitro cytocompatibility of the ES-SF tubes was confirmed by the adhesion and growth of primary porcine smooth muscle cells. The in vivo subcutaneous implant into the rat dorsal tissue indicated that ES-SF matrices caused a mild host reaction. Thus, the results of this investigation, in which comprehensive morphological and mechanical aspects, in vitro degradation and in vitro and in vivo biocompatibility were considered, indicate the potential suitability of these ES-SF tubular matrices as scaffolds for the regeneration of small diameter blood vessels. Copyright © 2015 Elsevier B.V. All rights reserved.

Pre-analytical and analytical aspects affecting clinical reliability of plasma glucose results.

PubMed

Pasqualetti, Sara; Braga, Federica; Panteghini, Mauro

2017-07-01

The measurement of plasma glucose (PG) plays a central role in recognizing disturbances in carbohydrate metabolism, with established decision limits that are globally accepted. This requires that PG results are reliable and unequivocally valid no matter where they are obtained. To control the pre-analytical variability of PG and prevent in vitro glycolysis, the use of citrate as rapidly effective glycolysis inhibitor has been proposed. However, the commercial availability of several tubes with studies showing different performance has created confusion among users. Moreover, and more importantly, studies have shown that tubes promptly inhibiting glycolysis give PG results that are significantly higher than tubes containing sodium fluoride only, used in the majority of studies generating the current PG cut-points, with a different clinical classification of subjects. From the analytical point of view, to be equivalent among different measuring systems, PG results should be traceable to a recognized higher-order reference via the implementation of an unbroken metrological hierarchy. In doing this, it is important that manufacturers of measuring systems consider the uncertainty accumulated through the different steps of the selected traceability chain. In particular, PG results should fulfil analytical performance specifications defined to fit the intended clinical application. Since PG has tight homeostatic control, its biological variability may be used to define these limits. Alternatively, given the central diagnostic role of the analyte, an outcome model showing the impact of analytical performance of test on clinical classifications of subjects can be used. Using these specifications, performance assessment studies employing commutable control materials with values assigned by reference procedure have shown that the quality of PG measurements is often far from desirable and that problems are exacerbated using point-of-care devices. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Automatic detection of oesophageal intubation based on ventilation pressure waveforms shows high sensitivity and specificity in patients with pulmonary disease.

PubMed

Kalmar, Alain F; Absalom, Anthony; Rombouts, Pieter; Roets, Jelle; Dewaele, Frank; Verdonck, Pascal; Stemerdink, Arjanne; Zijlstra, Jan G; Monsieurs, Koenraad G

2016-08-01

Unrecognised endotracheal tube misplacement in emergency intubations has a reported incidence of up to 17%. Current detection methods have many limitations restricting their reliability and availability in these circumstances. There is therefore a clinical need for a device that is small enough to be practical in emergency situations and that can detect oesophageal intubation within seconds. In a first reported evaluation, we demonstrated an algorithm based on pressure waveform analysis, able to determine tube location with high reliability in healthy patients. The aim of this study was to validate the specificity of the algorithm in patients with abnormal pulmonary compliance, and to demonstrate the reliability of a newly developed small device that incorporates the technology. Intubated patients with mild to moderate lung injury, admitted to intensive care were included in the study. The device was connected to the endotracheal tube, and three test ventilations were performed in each patient. All diagnostic data were recorded on PC for subsequent specificity/sensitivity analysis. A total of 105 ventilations in 35 patients with lung injury were analysed. With the threshold D-value of 0.1, the system showed a 100% sensitivity and specificity to diagnose tube location. The algorithm retained its specificity in patients with decreased pulmonary compliance. We also demonstrated the feasibility to integrate sensors and diagnostic hardware in a small, portable hand-held device for convenient use in emergency situations. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Comparison of palladium and zirconium treated graphite tubes for in-atomizer trapping of hydrogen selenide in hydride generation electrothermal atomization atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Laborda, Francisco; Medrano, Jesús; Cortés, José I.; Mir, José M.; Castillo, Juan R.

1999-02-01

Zirconium treated graphite tubes were investigated and compared with non-treated and palladium coated ones for in situ trapping of selenium hydride generated in a flow injection system. Selenium was effectively trapped on zirconium treated tubes at trapping temperatures of 300-600°C, similar to those observed for palladium, whereas trapping temperatures higher than 600°C had to be used with non-treated tubes. Zirconium treated tubes used in this work showed good stability up to 300 trapping/atomization cycles, with precision better than 5%, characteristic masses of 42 (peak height) and 133 pg (peak area) of selenium were obtained. Sensitivity of zirconium and palladium treatments were similar, but zirconium offered the advantage of a single application per tube. Detection limits were 0.11 (peak height) and 0.23 ng (peak area) for a 1 ml sample volume.

Role of structural defects in the ultraviolet luminescence of multiwall boron nitride nanotubes

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

Pierret, Aurélie; Nong, Hanond; Fossard, Frédéric

2015-12-21

BN nanotubes (BNNTs) are structurally similar to their carbon counterparts, though much less investigated. New synthesis methods have been recently reported, enabling the production of industrial quantities and stimulating the search of new applications for the BNNTs. In this paper, we investigate the luminescence of multiwall BNNTs. By performing cathodoluminescence experiments on single tubes at 10 K, we show that the tube luminescence is highly heterogeneous (i) from tube to tube and (ii) spatially along a single tube. By combining cathodoluminescence measurements with a nanometer excitation and transmission electron microscopy on the same tube, we correlate luminescence and structural features. Wemore » conclude that the near-band-edge luminescence of BNNTs (≈5.4 eV) is related to the presence of extended structural defects, such as dislocations or ruptures in the wall stacking.« less

Control of water and nutrients using a porous tube - A method for growing plants in space

NASA Technical Reports Server (NTRS)

Dreschel, Thomas W.; Sager, John C.

1989-01-01

A plant nutrient delivery system that uses a microporous, hydrophilic tube was developed with potential application for crop production in the microgravity of space. The tube contains a nutrient solution and delivers it to the roots. Pumps attached to the tubing create a very small suction that holds the solution within the tube. This system was used to grow wheat for 107 d in a controlled environment at suctions of 0.40, 1.48, or 2.58 kPa. The water absorbed through the pores of the tube by baby diaper sections decreased as suction increased. Correspondingly, final plant biomass, seed number, and spikelet number also tended to decrease as suction increased. The reduced yield at higher suction suggests that the plants experienced water stress, although all suctions were below those typical of soils at field capacity.

J-resistance curves for Inconel 690 and Incoloy 800 nuclear steam generators tubes at room temperature and at 300 °C

NASA Astrophysics Data System (ADS)

Bergant, Marcos A.; Yawny, Alejandro A.; Perez Ipiña, Juan E.

2017-04-01

The structural integrity of steam generator tubes is a relevant issue concerning nuclear plant safety. In the present work, J-resistance curves of Inconel 690 and Incoloy 800 nuclear steam generator tubes with circumferential and longitudinal through wall cracks were obtained at room temperature and 300 °C using recently developed non-standard specimens' geometries. It was found that Incoloy 800 tubes exhibited higher J-resistance curves than Inconel 690 for both crack orientations. For both materials, circumferential cracks resulted into higher fracture resistance than longitudinal cracks, indicating a certain degree of texture anisotropy introduced by the tube fabrication process. From a practical point of view, temperature effects have found to be negligible in all cases. The results obtained in the present work provide a general framework for further application to structural integrity assessments of cracked tubes in a variety of nuclear steam generator designs.

Ovarian, Fallopian Tube, & Primary Peritoneal Cancer Prevention (PDQ®)—Health Professional Version

Cancer.gov

Ovarian, fallopian tube, and primary peritoneal cancer prevention involves understanding risk and protective factors, and the evidence behind them. Get detailed information about specific risk and protective factors and prevention strategies for these cancer types in this clinician summary.

DHSEM Home

Science.gov Websites

Facebook YouTube logo YouTube News & Announcements New FY 18 Nonprofit Security Grant Program (NSGP ) - Applications DUE June 11, 2018 6:00pm New Press Release - Newtok Awarded HMGP Grant for Erosion Threatened Homes Hazard Mitigation Grant Program (HMGP) Funds Availability Announcement Fact Sheet - Preparing for

Thermal Blood Clot Formation and use in Microfluidic Device Valving Applications

NASA Technical Reports Server (NTRS)

Tai, Yu-Chong (Inventor); Shi, Wendian (Inventor); Guo, Luke (Inventor)

2014-01-01

The present invention provides a method of forming a blood-clot microvalve by heating blood in a capillary tube of a microfluidic device. Also described are methods of modulating liquid flow in a capillary tube by forming and removing a blood-clot microvalve.

Experimental Investigation of Reynolds Number Effects on Test Quality in a Hypersonic Expansion Tube

NASA Astrophysics Data System (ADS)

Rossmann, Tobias; Devin, Alyssa; Shi, Wen; Verhoog, Charles

2017-11-01

Reynolds number effects on test time and the temporal and spatial flow quality in a hypersonic expansion tube are explored using high-speed pressure, infrared optical, and Schlieren imaging measurements. Boundary layer models for shock tube flows are fairly well established to assist in the determination of test time and flow dimensions at typical high enthalpy test conditions. However, the application of these models needs to be more fully explored due to the unsteady expansion of turbulent boundary layers and contact regions separating dissimilar gasses present in expansion tube flows. Additionally, expansion tubes rely on the development of a steady jet with a large enough core-flow region at the exit of the acceleration tube to create a constant velocity region inside of the test section. High-speed measurements of pressure and Mach number at several locations within the expansion tube allow for the determination of an experimental x-t diagram. The comparison of the experimentally determined x-t diagram to theoretical highlights the Reynolds number dependent effects on expansion tube. Additionally, spatially resolved measurements of the Reynolds number dependent, steady core-flow in the expansion tube viewing section are shown. NSF MRI CBET #1531475, Lafayette College, McCutcheon Foundation.

High power linear pulsed beam annealer. [Patent application

DOEpatents

Strathman, M.D.; Sadana, D.K.; True, R.B.

1980-11-26

A high power pulsed electron beam system for annealing semiconductors is comprised of an electron gun having a heated cathode, control grid and focus ring for confining the pulsed beam of electrons to a predetermined area, and a curved drift tube. The drift tube and an annular Faraday shield between the focus ring and the drift tube are maintained at a high positive voltage with respect to the cathode to accelerate electrons passing through the focus ring, thereby eliminating space charge limitations on the emission of electrons from said gun. A coil surrounding the curved drift tube provides a magnetic field which maintains the electron beam focused about the axis of the tube. The magnetic field produced by the coil around the curved tube imparts motion to electrons in a spiral path for shallow penetration of the electrons into a target. It also produces a scalloped profile of the electron beam. A second drift tube spaced a predetermined distance from the curved tube is positioned with its axis aligned with the axis of the first drift tube. The second drift tube and the target holder are maintained at a reference voltage between the cathode voltage and the curved tube voltage to decelerate the electrons. A second coil surrounding the second drift tube, maintains the electron beam focused about the axis of the second drift tube. The magnetic field of the second coil comprises the electron beam to the area of the semiconductor on the target holder.

"On-command" dissolvable tympanostomy tube in the chinchilla model: A proof of concept.

PubMed

Wiedermann, Joshua P; Mai, Johnny P; Dumont, Matthieu; Jenkins, Audrey; Cleary, Kevin; Reilly, Brian K

2017-10-01

To prove the concept that a dissolvable "on-command" tympanostomy tube placed into the tympanic membrane of a chinchilla can dissolve when a benign solution is applied and result in a well healed tympanic membrane without histologic evidence of injury. Prospective Randomized Single-Subject Controlled Trial. Prototype tympanostomy tubes were fabricated from poly(butyl methacrylate-co-(2-dimethylaminoethyl) methacrylate-co- methyl methacrylate) (PBM). "In vitro" dissolution studies were performed with applications of the benign chemical, hydrogen peroxide (HP). PBM tubes were placed into ten chinchilla tympanic membranes matched with standard plastic tubes placed into the contralateral side. All 20 tubes were exposed to HP for 21 days with serial endoscopic examinations. In vitro PBM tubes were weighed before and after interventions and compared to control tubes. In vivo photo documentation was used to show progression of dissolution and histologic slides were obtained to show the effect of the PBM on surrounding tissues. Compared to control tubes, all those exposed to hydrogen peroxide had a statistically significant reduction in weight (p < 0.01). After placement into the tympanic membrane of chinchillas, all PBM tubes dissolved within 21 days of hydrogen peroxide treatment leaving behind histologically normal, intact tympanic membranes. Our PBM tubes dissolve "on-command" in a chinchilla model when exposed to treatment with a benign chemical. Dissolvable "on-command" tympanostomy tubes may reduce significant complications related to pediatric tympanostomy tube use. Copyright © 2017 Elsevier B.V. All rights reserved.

The axial crushes behaviour on foam-filled round Jute/Polyester composite tubes

NASA Astrophysics Data System (ADS)

Othman, A.; Ismail, A. E.

2018-04-01

The present paper investigates the effect of axial loading compression on jute fibre reinforced polyester composite round tubes. The specimen of composite tube was fabricated by hand lay-up method of 120 mm length with fix 50.8 mm inner diameter to determine the behaviour of energy absorption on number of layers of 450 angle fibre and internally reinforced with and without foam filler material. The foam filler material used in this studies were polyurethane (PU) and polystyrene (PE) with average of 40 and 45 kg/m3 densities on the axial crushing load against displacement relations and on the failure modes. The number of layers of on this study were two; three and four were selected to calculate the crush force efficiency (CFE) and the specific energy absorption (SEA) of the composite tubes. Result indicated that the four layers’ jute/polyester show significant value in term of crushing load compared to 2 and 3 layers higher 60% for 2 layer and 3% compared to 3 layers. It has been found that the specific energy absorption of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 10% to 12% than empty and polyurethane (PU) foam tubes. The increase in the number of layers from two to four increases the mean axial load from 1.01 KN to 3.60 KN for empty jute/polyester and from 2.11 KN to 4.26 KN for the polyurethane (PU) foam-filled jute/polyester tubes as well as for 3.60 KN to 5.58 KN for the polystyrene (PE) foam-filled jute/polyester. The author’s found that the failure of mechanism influence the characteristic of curve load against displacement obtained and conclude that an increasing number of layers and introduce filler material enhance the capability of specific absorbed energy.

Construction of 3-D Audio Systems: Background, Research, and General Requirements

DTIC Science & Technology

2008-10-01

silicone rubber tube. This tube was placed such that its tip was 1 to 2 mm from the listener’s eardrum and was held in position using a customised ...but implemented different techniques to create the customised shells used to keep the probe microphone in place. They chose to use the same moulding...why this is not a convenient procedure for commercial applications. This is particularly true where the application is aimed at a mass market where

Tube-Forming Assays.

PubMed

Brown, Ryan M; Meah, Christopher J; Heath, Victoria L; Styles, Iain B; Bicknell, Roy

2016-01-01

Angiogenesis involves the generation of new blood vessels from the existing vasculature and is dependent on many growth factors and signaling events. In vivo angiogenesis is dynamic and complex, meaning assays are commonly utilized to explore specific targets for research into this area. Tube-forming assays offer an excellent overview of the molecular processes in angiogenesis. The Matrigel tube forming assay is a simple-to-implement but powerful tool for identifying biomolecules involved in angiogenesis. A detailed experimental protocol on the implementation of the assay is described in conjunction with an in-depth review of methods that can be applied to the analysis of the tube formation. In addition, an ImageJ plug-in is presented which allows automatic quantification of tube images reducing analysis times while removing user bias and subjectivity.

Enlargement of halloysite clay nanotube lumen by selective etching of aluminum oxide.

PubMed

Abdullayev, Elshad; Joshi, Anupam; Wei, Wenbo; Zhao, Yafei; Lvov, Yuri

2012-08-28

Halloysite clay tubes have 50 nm diameter and chemically different inner and outer walls (inner surface of aluminum oxide and outer surface of silica). Due to this different chemistry, the selective etching of alumina from inside the tube was realized, while preserving their external diameter (lumen diameter changed from 15 to 25 nm). This increases 2-3 times the tube lumen capacity for loading and further sustained release of active chemical agents such as metals, corrosion inhibitors, and drugs. In particular, halloysite loading efficiency for the benzotriazole increased 4 times by selective etching of 60% alumina within the tubes' lumens. Specific surface area of the tubes increased over 6 times, from 40 to 250 m(2)/g, upon acid treatment.

Fabricating Copper Nanotubes by Electrodeposition

NASA Technical Reports Server (NTRS)

Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

2009-01-01

Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

Design of a Miniature Pulse Tube Cryocooler for Space Applications

NASA Astrophysics Data System (ADS)

Trollier, T.; Ravex, A.; Charles, I.; Duband, L.; Mullié, J.; Bruins, P.; Benschop, T.; Linder, M.

2004-06-01

An Engineering Model (EM) of a Miniature Pulse Tube Cooler (MPTC) has been designed and manufactured. The expected performance of the MPTC were 1240 mW heat lift at 80 K with 288 K ambient temperature and 40 Watts rms maximum input power to the compressor motors. The EM is a U shape configuration operated with an inertance tube. The design and optimisation of the compressor and the Pulse Tube cold finger are described. The thermal performance test results are presented and discussed as well. This work is performed within a Technological Research Project (TRP) funded by ESA (Contract 14896/00/NL/PA).

A critical review of liquid helium temperature high frequency pulse tube cryocoolers for space applications

NASA Astrophysics Data System (ADS)

Wang, B.; Gan, Z. H.

2013-08-01

The importance of liquid helium temperature cooling technology in the aerospace field is discussed, and the results indicate that improving the efficiency of liquid helium cooling technologies, especially the liquid helium high frequency pulse tube cryocoolers, is the principal difficulty to be solved. The state of the art and recent developments of liquid helium high frequency pulse tube cryocoolers are summarized. The main scientific challenges for high frequency pulse tube cryocoolers to efficiently reach liquid helium temperatures are outlined, and the research progress addressing those challenges are reviewed. Additionally some possible solutions to the challenges are pointed out and discussed.

GRID BLACKOUT IN VACUUM TUBES

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

Hardin, K.D.

1961-06-01

A method which gives quantitative data is presented which allows for characterization of the grid blackout effect and is applicable to calculation of circuit degradation. Data are presented for several tube types which show developed bias and discharge time constants as a function of pulse input conditions. Blackout can seriously change the performance of any vacuum tube circuit which utilizes the tube in positive grid operation. The effects on CW oscillators and UHF mixers are discussed. An equivalent circuit which simulates some portions of the blackout phenomenon is presented and used to calculate effective capacitance and resistance associated with themore » grid surface. (auth)« less

Thermal expansion method for lining tantalum alloy tubing with tungsten

NASA Technical Reports Server (NTRS)

Watson, G. K.; Whittenberger, J. D.; Mattson, W. F.

1973-01-01

A differential-thermal expansion method was developed to line T-111 (tantalum - 8 percent tungsten - 2 percent hafnium) tubing with a tungsten diffusion barrier as part of a fuel element fabrication study for a space power nuclear reactor concept. This method uses a steel mandrel, which has a larger thermal expansion than T-111, to force the tungsten against the inside of the T-111 tube. Variables investigated include lining temperature, initial assembly gas size, and tube length. Linear integrity increased with increasing lining temperature and decreasing gap size. The method should have more general applicability where cylinders must be lined with a thin layer of a second material.

Study of foldable elastic tubes for large space structure applications, phase 1

NASA Technical Reports Server (NTRS)

Jones, I. W.; Boateng, C.; Williams, C. D.

1980-01-01

Structural members that might be suitable for strain energy deployable structures, are discussed with emphasis on a thin-walled cylindrical tube with a cross-section that is called 'bi-convex'. The design of bi-convex tube test specimens and their fabrication are described as well as the design and construction of a special purpose testing machine to determine the deployment characteristics. The results of the first series of tests were quite mixed, but clearly revealed that since most of the specimens failed to deploy completely, due to a buckling problem, this type of tube requires some modification in order to be viable.

Development of a Versatile Laser-Ultrasonic System and Application to the Online Measurement for Process Control of Wall Thickness and Eccentricity of Seamless Tubes

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

Robert V. Kolarik II

2002-10-23

A system for the online, non-contact measurement of wall thickness in steel seamless mechanical tubing has been developed and demonstrated at a tubing production line at the Timken Company in Canton, Ohio. The system utilizes laser-generation of ultrasound and laser-detection of time of flight with interferometry, laser-doppler velocimetry and pyrometry, all with fiber coupling. Accuracy (<1% error) and precision (1.5%) are at targeted levels. Cost and energy savings have exceeded estimates. The system has shown good reliability in measuring over 200,000 tubes in its first six months of deployment.

Modeling of microjoule and millijoule energy LIDARs with PMT/SiPM/APD detectors: a sensitivity analysis.

PubMed

Agishev, Ravil

2018-05-10

This paper demonstrates a renewed concept and applications of the generalized methodology for atmospheric light detection and ranging (LIDAR) capability prediction as a continuation of a series of our previous works, where the dimensionless parameterization appeared as a tool for comparing systems of a different scale, design, and applications. The modernized concept applied to microscale and milliscale LIDARs with relatively new silicon photomultiplier detectors and traditional photomultiplier tube and avalanche photodiode detectors allowed prediction of the remote sensing instruments' performance and limitations. Such a generalized, uniform, and objective concept is applied for evaluation of the increasingly popular class of limited-energy LIDARs using the best optical detectors, operating on different targets (back-scatter or topographic, static or dynamic) and under intense sky background conditions. It can be used in the LIDAR community to compare different instruments and select the most suitable and effective ones for specific applications.

Development of a Highly Sensitive Nested-PCR Procedure Using a Single Closed Tube for Detection of Erwinia amylovora in Asymptomatic Plant Material

PubMed Central

Llop, Pablo; Bonaterra, Anna; Peñalver, Javier; López, María M.

2000-01-01

A novel method, which involves a nested PCR in a single closed tube, was developed for the sensitive detection of Erwinia amylovora in plant material. The external and internal primer pairs used had different annealing temperatures and directed the amplification of a specific DNA fragment from plasmid pEA29. The procedure involved two consecutive PCRs, the first of which was performed at a higher annealing temperature that allowed amplification only by the external primer pair. Using pure cultures of E. amylovora, the sensitivity of the nested PCR in one tube was similar to that of a standard nested PCR in two tubes. The specificity and sensitivity were greater than those of standard PCR procedures that used a single primer pair. The presence of inhibitors in plant material, very common in E. amylovora hosts, is overcome with this system in combination with a simple DNA extraction protocol because it eliminates many of the inhibitory compounds. In addition, it needs a very small sample volume (1 μl of DNA extracted). With 83 samples of naturally infected material, this method achieved better results than any other PCR technique: standard PCR detected 55% of positive samples, two-tube nested PCR detected 71% of positive samples, and nested PCR in a single closed tube detected 78% of positive samples. When analyzing asymptomatic plant material, the number of positive samples detected by the developed nested PCR was also the highest, compared with the PCR protocols indicated previously (17, 20, and 25% of 251 samples analyzed, respectively). This method is proposed for the detection of endophytic and epiphytic populations of E. amylovora in epidemiological studies and for routine use in quarantine surveys, due to its high sensitivity, specificity, speed, and simplicity. PMID:10788384

Use of a holder-vacuum tube device to save on-site hands in preparing urine samples for head-space gas-chromatography, and its application to determine the time allowance for sample sealing.

PubMed

Kawai, Toshio; Sumino, Kimiaki; Ohashi, Fumiko; Ikeda, Masayuki

2011-01-01

To facilitate urine sample preparation prior to head-space gas-chromatographic (HS-GC) analysis. Urine samples containing one of the five solvents (acetone, methanol, methyl ethyl ketone, methyl isobutyl ketone and toluene) at the levels of biological exposure limits were aspirated into a vacuum tube via holder, a device commercially available for venous blood collection (the vacuum tube method). The urine sample, 5 ml, was quantitatively transferred to a 20-ml head-space vial prior to HS-GC analysis. The loaded tubes were stored at +4 ℃ in dark for up to 3 d. The vacuum tube method facilitated on-site procedures of urine sample preparation for HS-GC with no significant loss of solvents in the sample and no need of skilled hands, whereas on-site sample preparation time was significantly reduced. Furthermore, no loss of solvents was detected during the 3-d storage, irrespective of hydrophilic (acetone) or lipophilic solvent (toluene). In a pilot application, high performance of the vacuum tube method in sealing a sample in an air-tight space succeeded to confirm that no solvent will be lost when sealing is completed within 5 min after urine voiding, and that the allowance time is as long as 30 min in case of toluene in urine. The use of the holder-vacuum tube device not only saves hands for transfer of the sample to air-tight space, but facilitates sample storage prior to HS-GC analysis.

Performance evaluation of cross-flow single-phase liquid-to-gas polymer tube heat exchanger

NASA Astrophysics Data System (ADS)

Dewanjee, Sujan; Hossain, Md. Rakibul; Rahman, Md. Ashiqur

2017-06-01

Reduced core weight and material cost, higher corrosion resistance are some of the major eye catching properties to study polymers over metal in heat exchanger applications in spite of the former's relatively low thermal conductivity and low strength. In the present study, performance of polymer parallel thin tube heat exchanger is numerically evaluated for cross flow liquid to air applications for a wide range of design and operating parameters such as tube diameter, thickness, fluid velocity and temperature, etc. using Computational Fluid Dynamics (CFD). Among a range of available polymeric materials, those with a moderate to high thermal conductivity and strength are selected for this study. A 90 cm × 1 cm single unit of polymer tubes, with appropriate number of tubes such that at least a gap of 5 mm is maintained in between the tubes, is used as a basic unit and multiple combination in the transverse direction of this single unit is simulated to measure the effect. The tube inner diameter is varied from 2 mm to 4 mm and the pressure drop is measured to have a relative idea of pumping cost. For each inner diameter the thickness is varied from .5 mm to 2.5 mm. The water velocity and the air velocity are varied from 0.4 m/s to 2 m/s and 1 m/s to 5 m/s, respectively. The performance of the polymer heat exchanger is compared with that of metal heat exchanger through and an optimum design for polymer heat exchanger is sought out.

High accuracy differential pressure measurements using fluid-filled catheters - A feasibility study in compliant tubes.

PubMed

Rotman, Oren Moshe; Weiss, Dar; Zaretsky, Uri; Shitzer, Avraham; Einav, Shmuel

2015-09-18

High accuracy differential pressure measurements are required in various biomedical and medical applications, such as in fluid-dynamic test systems, or in the cath-lab. Differential pressure measurements using fluid-filled catheters are relatively inexpensive, yet may be subjected to common mode pressure errors (CMP), which can significantly reduce the measurement accuracy. Recently, a novel correction method for high accuracy differential pressure measurements was presented, and was shown to effectively remove CMP distortions from measurements acquired in rigid tubes. The purpose of the present study was to test the feasibility of this correction method inside compliant tubes, which effectively simulate arteries. Two tubes with varying compliance were tested under dynamic flow and pressure conditions to cover the physiological range of radial distensibility in coronary arteries. A third, compliant model, with a 70% stenosis severity was additionally tested. Differential pressure measurements were acquired over a 3 cm tube length using a fluid-filled double-lumen catheter, and were corrected using the proposed CMP correction method. Validation of the corrected differential pressure signals was performed by comparison to differential pressure recordings taken via a direct connection to the compliant tubes, and by comparison to predicted differential pressure readings of matching fluid-structure interaction (FSI) computational simulations. The results show excellent agreement between the experimentally acquired and computationally determined differential pressure signals. This validates the application of the CMP correction method in compliant tubes of the physiological range for up to intermediate size stenosis severity of 70%. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preliminary Study on Biosynthesis of Bacterial Nanocellulose Tubes in a Novel Double-Silicone-Tube Bioreactor for Potential Vascular Prosthesis.

PubMed

Hong, Feng; Wei, Bin; Chen, Lin

2015-01-01

Bacterial nanocellulose (BNC) has demonstrated a tempting prospect for applications in substitute of small blood vessels. However, present technology is inefficient in production and BNC tubes have a layered structure that may bring danger after implanting. Double oxygen-permeable silicone tubes in different diameters were therefore used as a tube-shape mold and also as oxygenated supports to construct a novel bioreactor for production of the tubular BNC materials. Double cannula technology was used to produce tubular BNC via cultivations with Acetobacter xylinum, and Kombucha, a symbiosis of acetic acid bacteria and yeasts. The results indicated that Kombucha gave higher yield and productivity of BNC than A. xylinum. Bacterial nanocellulose was simultaneously synthesized both on the inner surface of the outer silicone tube and on the outer surface of the inner silicone tube. Finally, the nano BNC fibrils from two directions formed a BNC tube with good structural integrity. Scanning electron microscopy inspection showed that the tubular BNC had a multilayer structure in the beginning but finally it disappeared and an intact BNC tube formed. The mechanical properties of BNC tubes were comparable with the reported value in literatures, demonstrating a great potential in vascular implants or in functional substitutes in biomedicine.

Preliminary Study on Biosynthesis of Bacterial Nanocellulose Tubes in a Novel Double-Silicone-Tube Bioreactor for Potential Vascular Prosthesis

PubMed Central

Wei, Bin; Chen, Lin

2015-01-01

Bacterial nanocellulose (BNC) has demonstrated a tempting prospect for applications in substitute of small blood vessels. However, present technology is inefficient in production and BNC tubes have a layered structure that may bring danger after implanting. Double oxygen-permeable silicone tubes in different diameters were therefore used as a tube-shape mold and also as oxygenated supports to construct a novel bioreactor for production of the tubular BNC materials. Double cannula technology was used to produce tubular BNC via cultivations with Acetobacter xylinum, and Kombucha, a symbiosis of acetic acid bacteria and yeasts. The results indicated that Kombucha gave higher yield and productivity of BNC than A. xylinum. Bacterial nanocellulose was simultaneously synthesized both on the inner surface of the outer silicone tube and on the outer surface of the inner silicone tube. Finally, the nano BNC fibrils from two directions formed a BNC tube with good structural integrity. Scanning electron microscopy inspection showed that the tubular BNC had a multilayer structure in the beginning but finally it disappeared and an intact BNC tube formed. The mechanical properties of BNC tubes were comparable with the reported value in literatures, demonstrating a great potential in vascular implants or in functional substitutes in biomedicine. PMID:26090420

Oxygenator Safety Evaluation: A Focus on Connection Grip Strength and Arterial Temperature Measurement Accuracy

PubMed Central

Newland, Richard F.; Baker, Robert A.; Sanderson, Andrew J.; Tuble, Sigrid C.; Tully, Phil J.

2012-01-01

Abstract: This report describes the assessment of three specific safety-related specifications in the consideration of an alternate oxygenator; first the grip strength relationship between various oxygenator connectors and SMARxT® tubing, second, the grip strength of various biopassive tubings and an isolated SMARxT® connector, and finally, the accuracy of the arterial outlet temperature measurement. Grip strength experiments for the connections between the SMARxT® tubing and the venous reservoir outlet and the oxygenator venous inlet and oxygenator arterial outlet of the Medtronic Affinity®, Sorin Synthesis®, Sorin Primox®, and Terumo Capiox® RX25 oxygenators were performed. In addition we compared the grip strength of polyvinyl chloride, Physio®, Trillium®, Carmeda®, X-Coating®, and SMARxT® tubing. The accuracy of the integrated arterial outlet temperature probes was determined by comparing the temperatures measured by the integrated probe with a precision reference thermometer. Connector grip strength comparisons for the evaluation oxygenators with SMARxT® tubing showed significant variation between oxygenators and connections (p = .02). Evaluation of the arterial outlet showed significant variation between evaluation oxygenators, while at the venous reservoir outlet and oxygenator inlet, there were no significant differences. Grip strength comparison data for the various tubing types demonstrated a main effect for tubing type F(5, 18) = 8.01, p = .002, ηp2 = .77. Temperature accuracy measurements demonstrated that all oxygenators overread the arterial outlet temperature at 15°C, whilst at temperatures ≥25°C, all oxygenators underread the arterial outlet temperature. The integrity of SMARxT® tubing connection is influenced by the connector type, and may decline over time, highlighting the importance to not consider interchanging components of the bypass circuit as inconsequential. PMID:22893983

Accumulation, selection and covariation of amino acids in sieve tube sap of tansy (Tanacetum vulgare) and castor bean (Ricinus communis): evidence for the function of a basic amino acid transporter and the absence of a γ-amino butyric acid transporter.

PubMed

Bauer, Susanne N; Nowak, Heike; Keller, Frank; Kallarackal, Jose; Hajirezaei, Mohamad-Reza; Komor, Ewald

2014-09-01

Sieve tube sap was obtained from Tanacetum by aphid stylectomy and from Ricinus after apical bud decapitation. The amino acids in sieve tube sap were analyzed and compared with those from leaves. Arginine and lysine accumulated in the sieve tube sap of Tanacetum more than 10-fold compared to the leaf extracts and they were, together with asparagine and serine, preferably selected into the sieve tube sap, whereas glycine, methionine/tryptophan and γ-amino butyric acid were partially or completely excluded. The two basic amino acids also showed a close covariation in sieve tube sap. The acidic amino acids also grouped together, but antagonistic to the other amino acids. The accumulation ratios between sieve tube sap and leaf extracts were smaller in Ricinus than in Tanacetum. Arginine, histidine, lysine and glutamine were enriched and preferentially loaded into the phloem, together with isoleucine and valine. In contrast, glycine and methionine/tryptophan were partially and γ-amino butyric acid almost completely excluded from sieve tube sap. The covariation analysis grouped arginine together with several neutral amino acids. The acidic amino acids were loaded under competition with neutral amino acids. It is concluded from comparison with the substrate specificities of already characterized plant amino acid transporters, that an AtCAT1-like transporter functions in phloem loading of basic amino acids, whereas a transporter like AtGAT1 is absent in phloem. Although Tanacetum and Ricinus have different minor vein architecture, their phloem loading specificities for amino acids are relatively similar. © 2014 Scandinavian Plant Physiology Society.

Regulation of Pollen Tube Growth by Transglutaminase

PubMed Central

Cai, Giampiero; Serafini-Fracassini, Donatella; Del Duca, Stefano

2013-01-01

In pollen tubes, cytoskeleton proteins are involved in many aspects of pollen germination and growth, from the transport of sperm cells to the asymmetrical distribution of organelles to the deposition of cell wall material. These activities are based on the dynamics of the cytoskeleton. Changes to both actin filaments and microtubules are triggered by specific proteins, resulting in different organization levels suitable for the different functions of the cytoskeleton. Transglutaminases are enzymes ubiquitous in all plant organs and cell compartments. They catalyze the post-translational conjugation of polyamines to different protein targets, such as the cytoskeleton. Transglutaminases are suggested to have a general role in the interaction between pollen tubes and the extracellular matrix during fertilization and a specific role during the self-incompatibility response. In such processes, the activity of transglutaminases is enhanced, leading to the formation of cross-linked products (including aggregates of tubulin and actin). Consequently, transglutaminases are suggested to act as regulators of cytoskeleton dynamics. The distribution of transglutaminases in pollen tubes is affected by both membrane dynamics and the cytoskeleton. Transglutaminases are also secreted in the extracellular matrix, where they may take part in the assembly and/or strengthening of the pollen tube cell wall. PMID:27137368

Optimal Area Profiles for Ideal Single Nozzle Air-Breathing Pulse Detonation Engines

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.

2003-01-01

The effects of cross-sectional area variation on idealized Pulse Detonation Engine performance are examined numerically. A quasi-one-dimensional, reacting, numerical code is used as the kernel of an algorithm that iteratively determines the correct sequencing of inlet air, inlet fuel, detonation initiation, and cycle time to achieve a limit cycle with specified fuel fraction, and volumetric purge fraction. The algorithm is exercised on a tube with a cross sectional area profile containing two degrees of freedom: overall exit-to-inlet area ratio, and the distance along the tube at which continuous transition from inlet to exit area begins. These two parameters are varied over three flight conditions (defined by inlet total temperature, inlet total pressure and ambient static pressure) and the performance is compared to a straight tube. It is shown that compared to straight tubes, increases of 20 to 35 percent in specific impulse and specific thrust are obtained with tubes of relatively modest area change. The iterative algorithm is described, and its limitations are noted and discussed. Optimized results are presented showing performance measurements, wave diagrams, and area profiles. Suggestions for future investigation are also discussed.

Stresses and deformations in cross-ply composite tubes subjected to a uniform temperature change

NASA Technical Reports Server (NTRS)

Hyer, M. W.; Cooper, D. E.; Cohen, D.

1986-01-01

This study investigates the effects of a uniform temperature change on the stresses and deformations of composite tubes and determines the accuracy of an approximate solution based on the principle of complementary virtual work. Interest centers on tube response away from the ends and so a planar elasticity approach is used. For the approximate solution a piecewise linear variation of stresses with the radial coordinate is assumed. The results from the approximate solution are compared with the elasticity solution. The stress predictions agree well, particularly peak interlaminar stresses. Surprisingly, the axial deformations also agree well, despite the fact that the deformations predicted by the approximate solution do not satisfy the interface displacement continuity conditions required by the elasticity solution. The study shows that the axial thermal expansion coefficient of tubes with a specific number of axial and circumferential layers depends on the stacking sequence. This is in contrast to classical lamination theory, which predicts that the expansion will be independent of the stacking arrangement. As expected, the sign and magnitude of the peak interlaminar stresses depend on stacking sequence. For tubes with a specific number of axial and circumferential layers, thermally induced interlaminar stresses can be controlled by altering stacking arrangement.

Predicting the mechanical behaviour of Kevlar/epoxy and carbon/epoxy filament-wound tubes

NASA Astrophysics Data System (ADS)

Cazeneuve, C.; Joguet, P.; Maile, J. C.; Oytana, C.

1992-11-01

The axial, hoop and shear moduli and failure conditions of carbon/epoxy and Kevlar/epoxy filament-wound tubes have been determined through respective applications of internal pressure, tension and torsion. The introduction in the laminated plate theory of a gradual reduction in individual moduli makes it possible to overcome the limitations of the theory and enables accurate predictions to be made of the linear and non-linear stress/strain curves of 90 deg +/- 0/90 deg tubes. The existence of a dominant layer in the failure of the multilayered tubes has been shown experimentally. When associated with a failure criterion applied to the dominant layer, the new model permits the prediction of tube failure. Agreement between calculated and experimental data is better than 5 percent.

Preanalytical management: serum vacuum tubes validation for routine clinical chemistry.

PubMed

Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Picheth, Geraldo; Guidi, Gian Cesare

2012-01-01

The validation process is essential in accredited clinical laboratories. Aim of this study was to validate five kinds of serum vacuum tubes for routine clinical chemistry laboratory testing. Blood specimens from 100 volunteers in five different serum vacuum tubes (Tube I: VACUETTE, Tube II: LABOR IMPORT, Tube III: S-Monovette, Tube IV: SST and Tube V: SST II) were collected by a single, expert phlebotomist. The routine clinical chemistry tests were analyzed on cobas 6000 module. The significance of the differences between samples was assessed by paired Student's t-test after checking for normality. The level of statistical significance was set at P < 0.005. Finally, the biases from Tube I, Tube II, Tube III, Tube IV and Tube V were compared with the current desirable quality specifications for bias (B), derived from biological variation. Basically, our validation will permit the laboratory or hospital managers to select the brand's vacuum tubes validated according him/her technical or economical reasons, in order to perform the following laboratory tests: glucose, total cholesterol, high density lipoprotein-cholesterol, triglycerides, total protein, albumin, blood urea nitrogen, uric acid, alkaline phosphatise, aspartate aminotransferase, gamma-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, direct bilirubin, calcium, iron, sodium and potassium. On the contrary special attention will be required if the laboratory already performs creatinine, amylase, phosphate and magnesium determinations and the quality laboratory manager intend to change the serum tubes. We suggest that laboratory management should both standardize the procedures and frequently evaluate the quality of in vitro diagnostic devices.

Preanalytical management: serum vacuum tubes validation for routine clinical chemistry

PubMed Central

Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Picheth, Geraldo; Guidi, Gian Cesare

2012-01-01

Introduction The validation process is essential in accredited clinical laboratories. Aim of this study was to validate five kinds of serum vacuum tubes for routine clinical chemistry laboratory testing. Materials and methods: Blood specimens from 100 volunteers in five diff erent serum vacuum tubes (Tube I: VACUETTE®, Tube II: LABOR IMPORT®, Tube III: S-Monovette®, Tube IV: SST® and Tube V: SST II®) were collected by a single, expert phlebotomist. The routine clinical chemistry tests were analyzed on cobas® 6000 module. The significance of the diff erences between samples was assessed by paired Student’s t-test after checking for normality. The level of statistical significance was set at P < 0.005. Finally, the biases from Tube I, Tube II, Tube III, Tube IV and Tube V were compared with the current desirable quality specifications for bias (B), derived from biological variation. Results and conclusions: Basically, our validation will permit the laboratory or hospital managers to select the brand’s vacuum tubes validated according him/her technical or economical reasons, in order to perform the following laboratory tests: glucose, total cholesterol, high density lipoprotein-cholesterol, triglycerides, total protein, albumin, blood urea nitrogen, uric acid, alkaline phosphatise, aspartate aminotransferase, gamma-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, direct bilirubin, calcium, iron, sodium and potassium. On the contrary special attention will be required if the laboratory already performs creatinine, amylase, phosphate and magnesium determinations and the quality laboratory manager intend to change the serum tubes. We suggest that laboratory management should both standardize the procedures and frequently evaluate the quality of in vitro diagnostic devices. PMID:22838184

Computational Modeling of Tissue Self-Assembly

NASA Astrophysics Data System (ADS)

Neagu, Adrian; Kosztin, Ioan; Jakab, Karoly; Barz, Bogdan; Neagu, Monica; Jamison, Richard; Forgacs, Gabor

As a theoretical framework for understanding the self-assembly of living cells into tissues, Steinberg proposed the differential adhesion hypothesis (DAH) according to which a specific cell type possesses a specific adhesion apparatus that combined with cell motility leads to cell assemblies of various cell types in the lowest adhesive energy state. Experimental and theoretical efforts of four decades turned the DAH into a fundamental principle of developmental biology that has been validated both in vitro and in vivo. Based on computational models of cell sorting, we have developed a DAH-based lattice model for tissues in interaction with their environment and simulated biological self-assembly using the Monte Carlo method. The present brief review highlights results on specific morphogenetic processes with relevance to tissue engineering applications. Our own work is presented on the background of several decades of theoretical efforts aimed to model morphogenesis in living tissues. Simulations of systems involving about 105 cells have been performed on high-end personal computers with CPU times of the order of days. Studied processes include cell sorting, cell sheet formation, and the development of endothelialized tubes from rings made of spheroids of two randomly intermixed cell types, when the medium in the interior of the tube was different from the external one. We conclude by noting that computer simulations based on mathematical models of living tissues yield useful guidelines for laboratory work and can catalyze the emergence of innovative technologies in tissue engineering.

Design and characterization of very high frequency pulse tube prototypes

NASA Astrophysics Data System (ADS)

Lopes, Diogo; Duval, Jean-Marc; Charles, Ivan; Butterworth, James; Trollier, Thierry; Tanchon, Julien; Ravex, Alain; Daniel, Christophe

2012-06-01

Weight and size are important features of a cryocooler when it comes to space applications. Given their reliability and low level of exported vibrations (due to the absence of moving cold parts), pulse tubes are good candidates for spatial purposes and their miniaturization has been the focus of many studies. We report on the design and performance of a small-scale very high frequency pulse tube prototype, modeled after two previous prototypes which were optimized with a numerical code.

An alternative method to amplify RNA without loss of signal conservation for expression analysis with a proteinase DNA microarray in the ArrayTube format.

PubMed

Schüler, Susann; Wenz, Ingrid; Wiederanders, B; Slickers, P; Ehricht, R

2006-06-12

Recent developments in DNA microarray technology led to a variety of open and closed devices and systems including high and low density microarrays for high-throughput screening applications as well as microarrays of lower density for specific diagnostic purposes. Beside predefined microarrays for specific applications manufacturers offer the production of custom-designed microarrays adapted to customers' wishes. Array based assays demand complex procedures including several steps for sample preparation (RNA extraction, amplification and sample labelling), hybridization and detection, thus leading to a high variability between several approaches and resulting in the necessity of extensive standardization and normalization procedures. In the present work a custom designed human proteinase DNA microarray of lower density in ArrayTube format was established. This highly economic open platform only requires standard laboratory equipment and allows the study of the molecular regulation of cell behaviour by proteinases. We established a procedure for sample preparation and hybridization and verified the array based gene expression profile by quantitative real-time PCR (QRT-PCR). Moreover, we compared the results with the well established Affymetrix microarray. By application of standard labelling procedures with e.g. Klenow fragment exo-, single primer amplification (SPA) or In Vitro Transcription (IVT) we noticed a loss of signal conservation for some genes. To overcome this problem we developed a protocol in accordance with the SPA protocol, in which we included target specific primers designed individually for each spotted oligomer. Here we present a complete array based assay in which only the specific transcripts of interest are amplified in parallel and in a linear manner. The array represents a proof of principle which can be adapted to other species as well. As the designed protocol for amplifying mRNA starts from as little as 100 ng total RNA, it presents an alternative method for detecting even low expressed genes by microarray experiments in a highly reproducible and sensitive manner. Preservation of signal integrity is demonstrated out by QRT-PCR measurements. The little amounts of total RNA necessary for the analyses make this method applicable for investigations with limited material as in clinical samples from, for example, organ or tumour biopsies. Those are arguments in favour of the high potential of our assay compared to established procedures for amplification within the field of diagnostic expression profiling. Nevertheless, the screening character of microarray data must be mentioned, and independent methods should verify the results.

Unusual CoS2 ellipsoids with anisotropic tube-like cavities and their application in supercapacitors.

PubMed

Zhang, Lei; Wu, Hao Bin; Lou, Xiong Wen

2012-07-14

Unusual CoS(2) ellipsoids with anisotropic tube-like cavities have been synthesized from the simultaneous thermal decomposition and sulfidation of a preformed cobalt carbonate precursor. The as-prepared CoS(2) ellipsoids show interesting supercapacitive properties with high capacitance and good cycling performance.

40 CFR 1065.130 - Engine exhaust.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-layer effects and to promote mixing. You may orient the crankcase exhaust tube's outlet in any direction... includes any applicable aftertreatment devices. (b) Aftertreatment configuration. If you do not use the... configurations. (2) You may use exhaust tubing that is not from the in-use exhaust system upstream of any...

40 CFR Table 1 to Subpart Cccccc... - Applicability Criteria and Management Practices for Gasoline Dispensing Facilities With Monthly...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Gallons of Gasoline or More If you own or operate Then you must 1. A new, reconstructed, or existing GDF... fill tube is used, it shall be provided with a submerged drop tube that extends the same distance from...

77 FR 63343 - Biweekly Notice: Applications and Amendments to Facility Operating Licenses and Combined Licenses...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-16

... PWR [Pressurized-Water Reactor] Steam Generator Tubes'' (Reference 32) and [Nuclear Energy Institute... maintains the required structural margins of the SG tubes for both normal and accident conditions. Nuclear Energy Institute 97-06, ``Steam Generator Program Guidelines'' (Reference 8), and NRC Regulatory Guide 1...

Failure Analysis and Magnetic Evaluation of Tertiary Superheater Tube Used in Gas-Fired Boiler

NASA Astrophysics Data System (ADS)

Mohapatra, J. N.; Patil, Sujay; Sah, Rameshwar; Krishna, P. C.; Eswarappa, B.

2018-02-01

Failure analysis was carried out on a prematurely failed tertiary superheater tube used in gas-fired boiler. The analysis includes a comparative study of visual examination, chemical composition, hardness and microstructure at failed region, adjacent and far to failure as well as on fresh tube. The chemistry was found matching to the standard specification, whereas the hardness was low in failed tube compared to the fish mouth opening region and the fresh tube. Microscopic examination of failed sample revealed the presence of spheroidal carbides of Cr and Mo predominantly along the grain boundaries. The primary cause of failure is found to be localized heating. Magnetic hysteresis loop (MHL) measurements were carried out to correlate the magnetic parameters with microstructure and mechanical properties to establish a possible non-destructive evaluation (NDE) for health monitoring of the tubes. The coercivity of the MHL showed a very good correlation with microstructure and mechanical properties deterioration enabling a possible NDE technique for the health monitoring of the tubes.

Effects of Fuel Distribution on Detonation Tube Performance

NASA Technical Reports Server (NTRS)

Perkins, Hugh Douglas

2002-01-01

A pulse detonation engine (PDE) uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Lack of mixture uniformity is commonly ignored when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform H2/air mixtures were analyzed using the SPARK two-dimensional Navier-Stokes CFD code with 7-step H2/air reaction mechanism. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios (phi), stoichiometric (phi = 1.00), fuel lean (phi = 0.90), and fuel rich (phi = 1.10), were studied. All mixtures were detonable throughout the detonation tube. It was found that various mixtures representing the same test section equivalence ratio had specific impulses within 1 percent of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance.

Pollen-Specific Aquaporins NIP4;1 and NIP4;2 Are Required for Pollen Development and Pollination in Arabidopsis thaliana

PubMed Central

Bienert, Gerd Patrick; Barberini, María Laura

2016-01-01

In flowers with dry stigmas, pollen development, pollination, and pollen tube growth require spatial and temporal regulation of water and nutrient transport. To better understand the molecular mechanisms involved in reproductive processes, we characterized NIP4;1 and NIP4;2, two pollen-specific aquaporins of Arabidopsis thaliana. NIP4;1 and NIP4;2 are paralogs found exclusively in the angiosperm lineage. Although they have 84% amino acid identity, they displayed different expression patterns. NIP4;1 has low expression levels in mature pollen, while NIP4;2 expression peaks during pollen tube growth. Additionally, NIP4;1pro:GUS flowers showed GUS activity in mature pollen and pollen tubes, whereas NIP4;2pro:GUS flowers only in pollen tubes. Single T-DNA mutants and double artificial microRNA knockdowns had fewer seeds per silique and reduced pollen germination and pollen tube length. Transport assays in oocytes showed NIP4;1 and NIP4;2 function as water and nonionic channels. We also found that NIP4;1 and NIP4;2 C termini are phosphorylated by a pollen-specific CPK that modifies their water permeability. Survival assays in yeast indicated that NIP4;1 also transports ammonia, urea, boric acid, and H2O2. Thus, we propose that aquaporins NIP4;1 and NIP4;2 are exclusive components of the reproductive apparatus of angiosperms with partially redundant roles in pollen development and pollination. PMID:27095837

Is knee pain information on YouTube videos perceived to be helpful? An analysis of user comments and implications for dissemination on social media.

PubMed

Meldrum, Sarah; Savarimuthu, Bastin Tr; Licorish, Sherlock; Tahir, Amjed; Bosu, Michael; Jayakaran, Prasath

2017-01-01

There is little research that characterises knee pain related information disseminated via social media. However, variances in the content and quality of such sources could compromise optimal patient care. This study explored the nature of the comments on YouTube videos related to non-specific knee pain, to determine their helpfulness to the users. A systematic search identified 900 videos related to knee pain on the YouTube database. A total of 3537 comments from 58 videos were included in the study. A categorisation scheme was developed and 1000 randomly selected comments were analysed according to this scheme. The most common category was the users providing personal information or describing a personal situation (19%), followed by appreciation or acknowledgement of others' inputs (17%) and asking questions (15%). Of the questions, 33% were related to seeking help in relation to a specific situation. Over 10% of the comments contained negativity or disagreement; while 4.4% of comments reported they intended to pursue an action, based on the information presented in the video and/or from user comments. It was observed that individuals commenting on YouTube videos on knee pain were most often soliciting advice and information specific to their condition. The analysis of comments from the most commented videos using a keyword-based search approach suggests that the YouTube videos can be used for disseminating general advice on knee pain.

Is knee pain information on YouTube videos perceived to be helpful? An analysis of user comments and implications for dissemination on social media

PubMed Central

Meldrum, Sarah; Savarimuthu, Bastin TR; Licorish, Sherlock; Tahir, Amjed; Bosu, Michael; Jayakaran, Prasath

2017-01-01

Objective There is little research that characterises knee pain related information disseminated via social media. However, variances in the content and quality of such sources could compromise optimal patient care. This study explored the nature of the comments on YouTube videos related to non-specific knee pain, to determine their helpfulness to the users. Methods A systematic search identified 900 videos related to knee pain on the YouTube database. A total of 3537 comments from 58 videos were included in the study. A categorisation scheme was developed and 1000 randomly selected comments were analysed according to this scheme. Results The most common category was the users providing personal information or describing a personal situation (19%), followed by appreciation or acknowledgement of others’ inputs (17%) and asking questions (15%). Of the questions, 33% were related to seeking help in relation to a specific situation. Over 10% of the comments contained negativity or disagreement; while 4.4% of comments reported they intended to pursue an action, based on the information presented in the video and/or from user comments. Conclusion It was observed that individuals commenting on YouTube videos on knee pain were most often soliciting advice and information specific to their condition. The analysis of comments from the most commented videos using a keyword-based search approach suggests that the YouTube videos can be used for disseminating general advice on knee pain. PMID:29942583

Stakeholder Values and Perspectives when Implementing Led Lights on Navy Ships

DTIC Science & Technology

2014-06-01

Additionally, the M1 IntelliTube is a retrofit lamp , 32 which works with line power or any of the legacy ballasts.” ( LED /IntelliTube NAVSEA: LED ...only factor taken into consideration, then break-even point for LED lighting, Navy- wide, is approximately one hour to change the lamp . Of note...Energy Focus. (2013, July 3). Energy Focus: Specifications: IntelliTube LED replacement lamp , 24”, T12 LED lamp . Retrieved from http

Foundation Elements for Naval Low-Rise Buildings

DTIC Science & Technology

2009-10-01

of < 2% by total mass (oven dry weight) using a steam tube dryer . Wood flour, polymer, and lubricants were then mixed in a low intensity blender...Allendale, NJ) was employed for HDPE blends. Specific formulations for each composite are outlined in Table 1. A steam tube dryer was utilized to reduce...materials were weighed and dry-blended in 350lb batches prior to profile extrusion. The wood flour was first dried with a steam tube dryer to a moisture

Characterization and implementation of OSL dosimeters for use in evaluating the efficacy of organ-based tube current modulation for CT scans of the face and orbits

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

Marsh, R. M.; Silosky, M., E-mail: michael.silosky@ucdenver.edu

Purpose: The purpose of this work was to characterize commercially available optically stimulated luminescent (OSL) dosimeters for general clinical applications and apply the results to the development of a method to evaluate the efficacy of a vendor-specific organ-based tube current modulation application for both phantom and clinical computed tomography (CT) scans of the face and orbits. Methods: This study consisted of three components: (1) thorough characterization of the dosimeters for CT scans in phantom, including evaluations of depletion, fading, angular dependence, and conversion from counts to absorbed dose; (2) evaluation of the efficacy of using plastic glasses to position themore » dosimeters over the eyes in both phantom and clinical studies; and (3) preliminary dosimetry measurements made using organ-based tube current modulation in computed tomography dose index (CTDI) and anthropomorphic phantom studies. Results: (1) Depletion effects were found to have a linear relationship with the output of the OSL dosimeters (R{sup 2} = 0.96). Fading was found to affect dosimeter readings during the first two hours following exposure but had no effect during the remaining 60-h period observed. No significant angular dependence was observed for the exposure conditions used in this study (with p-values ranging from 0.9 to 0.26 for all t-tests). Dosimeter counts varied linearly with absorbed dose when measured in the center and 12 o’clock positions of the CTDI phantoms. These linear models of counts versus absorbed dose had overlapping 95% confidence intervals for the intercepts but not for the slopes. (2) When dosimeters were positioned using safety glasses, there was no adverse effect on image quality, and there was no statistically significant difference between this placement and placement of the dosimeters directly on the eyes of the phantom (p = 0.24). (3) When using organ-based tube current modulation, the dose to the lens of the eye was reduced between 19% and 43%, depending on the scan protocol used and the positioning of the phantom. Furthermore, the amount of dose reduction was significantly affected by the vertical position of the phantom, with the largest reduction in dose seen when the phantom was centered in the gantry. Conclusions: (1) An appropriate correction factor, specific to CT scanning, was developed to account for depletion and fading characteristics of the dosimeters. Additionally, an equation to convert dosimeter counts to absorbed dose was established. (2) The use of plastic safety glasses was validated as an appropriate positioning device when measuring dose to the lens of the eye. (3) The use of organ-based tube current modulation can reduce dose to the lens of the eye during CT scanning. The amount of dose reduction, however, is largely influenced by the positioning of the anatomy in the gantry.« less

Characterization and implementation of OSL dosimeters for use in evaluating the efficacy of organ-based tube current modulation for CT scans of the face and orbits.

PubMed

Marsh, R M; Silosky, M

2015-04-01

The purpose of this work was to characterize commercially available optically stimulated luminescent (OSL) dosimeters for general clinical applications and apply the results to the development of a method to evaluate the efficacy of a vendor-specific organ-based tube current modulation application for both phantom and clinical computed tomography (CT) scans of the face and orbits. This study consisted of three components: (1) thorough characterization of the dosimeters for CT scans in phantom, including evaluations of depletion, fading, angular dependence, and conversion from counts to absorbed dose; (2) evaluation of the efficacy of using plastic glasses to position the dosimeters over the eyes in both phantom and clinical studies; and (3) preliminary dosimetry measurements made using organ-based tube current modulation in computed tomography dose index (CTDI) and anthropomorphic phantom studies. (1) Depletion effects were found to have a linear relationship with the output of the OSL dosimeters (R(2) = 0.96). Fading was found to affect dosimeter readings during the first two hours following exposure but had no effect during the remaining 60-h period observed. No significant angular dependence was observed for the exposure conditions used in this study (with p-values ranging from 0.9 to 0.26 for all t-tests). Dosimeter counts varied linearly with absorbed dose when measured in the center and 12 o'clock positions of the CTDI phantoms. These linear models of counts versus absorbed dose had overlapping 95% confidence intervals for the intercepts but not for the slopes. (2) When dosimeters were positioned using safety glasses, there was no adverse effect on image quality, and there was no statistically significant difference between this placement and placement of the dosimeters directly on the eyes of the phantom (p = 0.24). (3) When using organ-based tube current modulation, the dose to the lens of the eye was reduced between 19% and 43%, depending on the scan protocol used and the positioning of the phantom. Furthermore, the amount of dose reduction was significantly affected by the vertical position of the phantom, with the largest reduction in dose seen when the phantom was centered in the gantry. (1) An appropriate correction factor, specific to CT scanning, was developed to account for depletion and fading characteristics of the dosimeters. Additionally, an equation to convert dosimeter counts to absorbed dose was established. (2) The use of plastic safety glasses was validated as an appropriate positioning device when measuring dose to the lens of the eye. (3) The use of organ-based tube current modulation can reduce dose to the lens of the eye during CT scanning. The amount of dose reduction, however, is largely influenced by the positioning of the anatomy in the gantry.

Sampling system and method

DOEpatents

Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

2017-03-07

In one embodiment, the present disclosure provides an apparatus and method for supporting a tubing bundle during installation or removal. The apparatus includes a clamp for securing the tubing bundle to an external wireline. In various examples, the clamp is external to the tubing bundle or integral with the tubing bundle. According to one method, a tubing bundle and wireline are deployed together and the tubing bundle periodically secured to the wireline using a clamp. In another embodiment, the present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit. In a specific example, one or more clamps are used to connect the first and/or second conduits to an external wireline.

3D integrated HYDRA simulations of hohlraums including fill tubes

NASA Astrophysics Data System (ADS)

Marinak, M. M.; Milovich, J.; Hammel, B. A.; Macphee, A. G.; Smalyuk, V. A.; Kerbel, G. D.; Sepke, S.; Patel, M. V.

2017-10-01

Measurements of fill tube perturbations from hydro growth radiography (HGR) experiments on the National Ignition Facility show spoke perturbations in the ablator radiating from the base of the tube. These correspond to the shadow of the 10 μm diameter glass fill tube cast by hot spots at early time. We present 3D integrated HYDRA simulations of these experiments which include the fill tube. Meshing techniques are described which were employed to resolve the fill tube structure and associated perturbations in the simulations. We examine the extent to which the specific illumination geometry necessary to accommodate a backlighter in the HGR experiment contributes to the spoke pattern. Simulations presented include high resolution calculations run on the Trinity machine operated by the Alliance for Computing at Extreme Scale (ACES) partnership. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

Computer output microfilm (FR80) systems software documentation, volume 2

NASA Technical Reports Server (NTRS)

1975-01-01

The system consists of a series of programs which convert digital data from magnetic tapes into alpha-numeric characters, graphic plots, and imagery that is recorded on the face of a cathode ray tube. A special camera photographs the face of the tube on microfilm for subsequent display on a film reader. The applicable documents which apply to this system are delineated. The functional relationship between the system software, the standard insert routines, and the applications programs is described; all the applications programs are described in detail. Instructions for locating those documents are presented along with test preparations sheets for all baseline and/or program modification acceptance tests.

Optimizations of geothermal cycle shell and tube exchangers of various configurations with variable fluid properties and site specific fouling. [SIZEHX

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

Pope, W.L.; Pines, H.S.; Silvester, L.F.

1978-03-01

A new heat exchanger program, SIZEHX, is described. This program allows single step multiparameter cost optimizations on single phase or supercritical exchanger arrays with variable properties and arbitrary fouling for a multitude of matrix configurations and fluids. SIZEHX uses a simplified form of Tinker's method for characterization of shell side performance; the Starling modified BWR equation for thermodynamic properties of hydrocarbons; and transport properties developed by NBS. Results of four parameter cost optimizations on exchangers for specific geothermal applications are included. The relative mix of capital cost, pumping cost, and brine cost ($/Btu) is determined for geothermal exchangers illustrating themore » invariant nature of the optimal cost distribution for fixed unit costs.« less

Closed loop control of a cylindrical tube type Ionic Polymer Metal Composite (IPMC)

NASA Astrophysics Data System (ADS)

Mead, Benjamin T.

The goal of this research is to provide a framework for the integration of tube type, cylindrical Ionic Polymer Metal-Composite (IPMC) into conventional devices. IPMCs are one of the most widely used types of electro-active polymer actuator, due to their low electric driving potential and large deformation range. For this research a tube type IPMC was investigated. This IPMC has a circular cross section with four separate electrodes on its surface and a hole through the middle. The four electrodes allow for biaxial bending and accurate control of the tip location. One of the main advantages of using this type of IPMC is the ability to embed a specific tool and accurately control the tool tip location using the large deflection range of the IPMC. This ability has widespread applications including in the biomedical field for use in active catheter procedures. First, this relatively new type of IPMC is investigated and characterized. The processes and materials used are described and the functional design is explored. Before the modeling process beings the basic functions of the IPMC are investigated. To this end force and displacement experiments are performed to describe the activation of the tube type IPMC. This data will be used later to verify and calibrate the mathematical simulations. Second, a three dimensional multi-physics finite element model is developed using COMSOL 4.3a. This model will automatically couple three physics packages and provide a description of the fluid interactions within the tube type IPMC. This model is then compared against the experimental displacement results to calibrate the simulation. Using this simulation design parameters are declared including, overall diameter, and tool hole size. The performance of the IPMC is then simulated while varying these parameters. Third, an electro-mechanical model of the IPMC is developed. This macroscopic model is used to relate the input voltage to an associated tip deflection. Several model types used for this purpose are tested and discussed. After determining a suitable type a mathematical electro-mechanical model is developed. Using this model several closed loop control systems are proposed. Once a final decision is reached the closed loop control system is implemented in the experimental setup. Several tests are designed to test the effectiveness of the closed loop system and mathematical models. Finally several improvements are made to enhance the users experience using IPMCs as well as incorporating them into conventional devices. To provide a better user interface the experimental control system is extended to allow the user to input controls via a standard computer mouse. This will allow a shorter operator training time and hopefully a wider array of real world uses for IPMCs. Attempts are also made to establish permanent connections to the IPMC. A tube type IPMC is meant to be used as part of a total system. To this end soldered connections to the IPMC are made. One of the main expected applications of tube type IPMCs are as active catheters. In this application the IPMC would be placed in-line with the plastic catheter line. As a proof of concept the IPMC is installed onto the tip of a conventional catheter line.

[Application research of presacral space drainage tube combined with subcutaneous vacuum pressure suction in the laparoscopic-assisted abdominoperineal resection].

PubMed

Chen, Liqi; Zeng, Changqing; Chi, Liangjie; Huang, Liangxiang; Li, Jiandang

2017-08-25

To study the management for the perineal incision after laparoscopic-assisted abdominoperineal resection for rectal cancer. Clinical data of 87 patients undergoing laparoscopic Miles operation for lower rectal cancer from June 2009 to February 2014 were collected and studied. Presacral space drainage group: presacral space drainage tube was applied in 42 patients. Combined drainage group: presacral space drainage tube combined with subcutaneous vacuum pressure suction was applied in 45 cases. In combined drainage group, except the presacral drainage tube, another drainage tube was placed subcutaneously and connected to a negative pressure ball, which was fixed on the lateral anterior of perineal wound by the further incision and drainage. After subcutaneous tube was placed for 2 weeks, as drainage fluid was limpid and <15 ml/d for 3 days, meanwhile no obvious pelvic fluid was detected by ultrasound, and the wound healed quite well without redness and edema, then the subcutaneous tube with the negative pressure ball could be removed. There were 51 males and 36 females with the mean age of 26-78(56.9±10.8) years old. The laparoscopic Miles operation was successfully completed in all the cases without death and complications. The drainage tube was placed for 4-13(8.0±2.5) days in presacral space drainage group, and for 4-14(6.7±2.4) days in combined drainage group. The subcutaneous tube was placed for 14-24(15.8±3.0) days. The primary healing rate of perineal wound in presacral space drainage group and combined drainage group was 66.7%(28/42) and 91.1%(41/45) respectively, while the perineal wound infection rate was 21.4%(9/42) and 4.4%(2/45) respectively, whose differences between two groups were both significant (χ 2 =7.911, P=0.005 and χ 2 =5.674, P=0.017). Presacral space drainage tube combined with subcutaneous vacuum pressure suction in laparoscopic-assisted abdominoperineal resection for rectal cancer has better efficacy and lower infection rate for perineal incision, which is worth wide application.

Update on Thales flexure bearing coolers and drive electronics

NASA Astrophysics Data System (ADS)

Willems, D.; Benschop, T.; v. d. Groep, W.; Mullié, J.; v. d. Weijden, H.; Tops, M.

2009-05-01

Thales Cryogenics has a long background in delivering cryogenic coolers with an MTTF far above 20.000 hrs for military, civil and space programs. Developments in these markets required continuous update of the flexure bearing cooler portfolio for new and emerging applications. The cooling requirements of new application have not only their influence on the size of the compressor, cold finger and cooling technology used but also on the integration and control of the cooler in the application. Thales Cryogenics developed a compact Cooler Drive Electronics based on DSP technology that could be used for driving linear flexure bearing coolers with extreme temperature stability and with additional diagnostics inside the CDE. This CDE has a wide application and can be modified to specific customer requirements. During the presentation the latest developments in flexure bearing cooler technology will be presented both for Stirling and Pulse Tube coolers. Also the relation between the most important recent detector requirements and possible available solutions on cryocooler level will be presented.

ALTERNATIVES TO HELIUM-3 FOR NEUTRON MULTIPLICITY DETECTORS

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

Ely, James H.; Siciliano, Edward R.; Swinhoe, Martyn T.

Collaboration between the Pacific Northwest National Laboratory (PNNL) and the Los Alamos National Laboratory (LANL) is underway to evaluate neutron detection technologies that might replace the high-pressure helium (3He) tubes currently used in neutron multiplicity counter for safeguards applications. The current stockpile of 3He is diminishing and alternatives are needed for a variety of neutron detection applications including multiplicity counters. The first phase of this investigation uses a series of Monte Carlo calculations to simulate the performance of an existing neutron multiplicity counter configuration by replacing the 3He tubes in a model for that counter with candidate alternative technologies. Thesemore » alternative technologies are initially placed in approximately the same configuration as the 3He tubes to establish a reference level of performance against the 3He-based system. After these reference-level results are established, the configurations of the alternative models will be further modified for performance optimization. The 3He model for these simulations is the one used by LANL to develop and benchmark the Epithermal Neutron Multiplicity Counter (ENMC) detector, as documented by H.O. Menlove, et al. in the 2004 LANL report LA-14088. The alternative technologies being evaluated are the boron-tri-fluoride-filled proportional tubes, boron-lined tubes, and lithium coated materials previously tested as possible replacements in portal monitor screening applications, as documented by R.T. Kouzes, et al. in the 2010 PNNL report PNNL-72544 and NIM A 623 (2010) 1035–1045. The models and methods used for these comparative calculations will be described and preliminary results shown« less

Sorbent-based sampling methods for volatile and semi-volatile organic compounds in air Part 1: Sorbent-based air monitoring options.

PubMed

Woolfenden, Elizabeth

2010-04-16

Sorbent tubes/traps are widely used in combination with gas chromatographic (GC) analytical methods to monitor the vapour-phase fraction of organic compounds in air. Target compounds range in volatility from acetylene and freons to phthalates and PCBs and include apolar, polar and reactive species. Airborne vapour concentrations will vary depending on the nature of the location, nearby pollution sources, weather conditions, etc. Levels can range from low percent concentrations in stack and vent emissions to low part per trillion (ppt) levels in ultra-clean outdoor locations. Hundreds, even thousands of different compounds may be present in any given atmosphere. GC is commonly used in combination with mass spectrometry (MS) detection especially for environmental monitoring or for screening uncharacterised workplace atmospheres. Given the complexity and variability of organic vapours in air, no one sampling approach suits every monitoring scenario. A variety of different sampling strategies and sorbent media have been developed to address specific applications. Key sorbent-based examples include: active (pumped) sampling onto tubes packed with one or more sorbents held at ambient temperature; diffusive (passive) sampling onto sorbent tubes/cartridges; on-line sampling of air/gas streams into cooled sorbent traps; and transfer of air samples from containers (canisters, Tedlar) bags, etc.) into cooled sorbent focusing traps. Whichever sampling approach is selected, subsequent analysis almost always involves either solvent extraction or thermal desorption (TD) prior to GC(/MS) analysis. The overall performance of the air monitoring method will depend heavily on appropriate selection of key sampling and analytical parameters. This comprehensive review of air monitoring using sorbent tubes/traps is divided into 2 parts. (1) Sorbent-based air sampling option. (2) Sorbent selection and other aspects of optimizing sorbent-based air monitoring methods. The paper presents current state-of-the-art and recent developments in relevant areas such as sorbent research, sampler design, enhanced approaches to analytical quality assurance and on-tube derivatisation. Copyright 2009 Elsevier B.V. All rights reserved.

Electrostatic Switching in Vertically Oriented Nanotubes for Nonvolatile Memory Applications

NASA Technical Reports Server (NTRS)

Kaul, Anupama B.; Khan, Paul; Jennings, Andrew T.; Greer, Julia R.; Megerian, Krikor G.; Allmen, Paul von

2009-01-01

We have demonstrated electrostatic switching in vertically oriented nanotubes or nanofibers, where a nanoprobe was used as the actuating electrode inside an SEM. When the nanoprobe was manipulated to be in close proximity to a single tube, switching voltages between 10 V - 40 V were observed, depending on the geometrical parameters. The turn-on transitions appeared to be much sharper than the turn-off transitions which were limited by the tube-to-probe contact resistances. In many cases, stiction forces at these dimensions were dominant, since the tube appeared stuck to the probe even after the voltage returned to 0 V, suggesting that such structures are promising for nonvolatile memory applications. The stiction effects, to some extent, can be adjusted by engineering the switch geometry appropriately. Nanoscale mechanical measurements were also conducted on the tubes using a custom-built anoindentor inside an SEM, from which preliminary material parameters, such as the elastic modulus, were extracted. The mechanical measurements also revealed that the tubes appear to be well adhered to the substrate. The material parameters gathered from the mechanical measurements were then used in developing an electrostatic model of the switch using a commercially available finite-element simulator. The calculated pull-in voltages appeared to be in agreement to the experimentally obtained switching voltages to first order.

A multi-frequency radar sounder for lava tubes detection on the Moon: Design, performance assessment and simulations

NASA Astrophysics Data System (ADS)

Carrer, Leonardo; Gerekos, Christopher; Bruzzone, Lorenzo

2018-03-01

Lunar lava tubes have attracted special interest as they would be suitable shelters for future human outposts on the Moon. Recent experimental results from optical images and gravitational anomalies have brought strong evidence of their existence, but such investigative means have very limited potential for global mapping of lava tubes. In this paper, we investigate the design requirement and feasibility of a radar sounder system specifically conceived for detecting subsurface Moon lava tubes from orbit. This is done by conducting a complete performance assessment and by simulating the electromagnetic signatures of lava tubes using a coherent 3D simulator. The results show that radar sounding of lava tubes is feasible with good performance margins in terms of signal-to-noise and signal-to-clutter ratio, and that a dual-frequency radar sounder would be able to detect the majority of lunar lava tubes based on their potential dimension with some limitations for very small lava tubes having width smaller than 250 m. The electromagnetic simulations show that lava tubes display an unique signature characterized by a signal phase inversion on the roof echo. The analysis is provided for different acquisition geometries with respect to the position of the sounded lava tube. This analysis confirms that orbiting multi-frequency radar sounder can detect and map in a reliable and unambiguous way the majority of Moon lava tubes.

Manufacturing Methods and Technology (MM&T) program. 10.6 micrometer carbon dioxide TEA (Transverely Excited Atmospheric) lasers

NASA Astrophysics Data System (ADS)

Luck, C. F.

1983-06-01

This report documents the efforts of Raytheon Company to conduct a manufacturing methods and technology (MM&T) program for 10.6 micrometer carbon dioxide TEA lasers. A set of laser parameters is given and a conforming tube design is described. Results of thermal and mechanical stress analyses are detailed along with a procedure for assembling and testing the laser tube. Also provided are purchase specifications for optics and process specifications for some of the essential operations.

Effect of Alignment on Transport Properties of Carbon Nanotube/Metallic Junctions

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Namkung, Min; Smits, Jan; Williams, Phillip; Harvey, Robert

2003-01-01

Ballistic and spin coherent transport in single walled carbon nanotubes (SWCNT) are predicted to enable high sensitivity single-nanotube devices for strain and magnetic field sensing. Based upon these phenomena, electron beam lithography procedures have been developed to study the transport properties of purified HiPCO single walled carbon nanotubes for development into sensory materials for nondestructive evaluation. Purified nanotubes are dispersed in solvent suspension and then deposited on the device substrate before metallic contacts are defined and deposited through electron beam lithography. This procedure produces randomly dispersed ropes, typically 2 - 20 nm in diameter, of single walled carbon nanotubes. Transport and scanning probe microscopy studies have shown a good correlation between the junction resistance and tube density, alignment, and contact quality. In order to improve transport properties of the junctions a technique has been developed to align and concentrate nanotubes at specific locations on the substrate surface. Lithographic techniques are used to define local areas where high frequency electric fields are to be concentrated. Application of the fields while the substrate is exposed to nanotube-containing solution results in nanotube arrays aligned with the electric field lines. A second electron beam lithography layer is then used to deposit metallic contacts across the aligned tubes. Experimental measurements are presented showing the increased tube alignment and improvement in the transport properties of the junctions.

Tubular fluoropolymer arrays with high piezoelectric response

NASA Astrophysics Data System (ADS)

Zhukov, Sergey; Eder-Goy, Dagmar; Biethan, Corinna; Fedosov, Sergey; Xu, Bai-Xiang; von Seggern, Heinz

2018-01-01

Polymers with electrically charged internal air cavities called ferroelectrets exhibit a pronounced piezoelectric effect and are regarded as soft functional materials suitable for sensor and actuator applications. In this work, a simple method for fabricating piezoelectret arrays with open-tubular channels is introduced. A set of individual fluoroethylenepropylene (FEP) tubes is compressed between two heated metal plates. The squeezed FEP tubes are melted together at +270 °C. The resulting structure is a uniform, multi-tubular, flat array that reveals a strong piezoelectric response after a poling step. The fabricated arrays have a high ratio between piezoelectrically active and non-active areas. The optimal charging voltage and stability of the piezoelectric coefficients with pressures and frequency were experimentally investigated for two specific array structures with wall thickness of 50 and 120 μm. The array fabricated from 50 μm thick FEP tubes reveals a stable and high piezoelectric coefficient of {d}33 = 120-160 pC N-1 with a flat frequency response between 0.1 Hz and 10 kHz for pressures between 1 and 100 kPa. An increase of wall thickness to 120 μm is accompanied by a more than twofold decrease in the piezoelectric coefficient as a result of a simultaneously higher effective array stiffness and lower remanent polarization. The obtained experimental results can be used to optimize the array design with regard to the electromechanical performance.

U-tube based near-surface environmental monitoring in the Shenhua carbon dioxide capture and storage (CCS) project.

PubMed

Li, Qi; Song, Ranran; Shi, Hui; Ma, Jianli; Liu, Xuehao; Li, Xiaochun

2018-04-01

The CO 2 injected into deep formations during implementation of carbon dioxide (CO 2 ) capture and storage (CCS) technology may leak and migrate into shallow aquifers or ground surfaces through a variety of pathways over a long period. The leaked CO 2 can threaten shallow environments as well as human health. Therefore, almost all monitoring programs for CCS projects around the world contain near-surface monitoring. This paper presents a U-tube based near-surface monitoring technology focusing on its first application in the Shenhua CCS demonstration project, located in the Ordos Basin, Inner Mongolia, China. First, background information on the site monitoring program of the Shenhua CCS demonstration project was provided. Then, the principle of fluid sampling and the monitoring methods were summarized for the U-tube sampler system, and the monitoring data were analyzed in detail. The U-tube based monitoring results showed that the U-tube sampler system is accurate, flexible, and representative of the subsurface fluid sampling process. The monitoring indicators for the subsurface water and soil gas at the Shenhua CCS site indicate good stratification characteristics. The concentration level of each monitoring indicator decreases with increasing depth. Finally, the significance of this near-surface environmental monitoring technology for CO 2 leakage assessments was preliminarily confirmed at the Shenhua CCS site. The application potential of the U-tube based monitoring technology was also demonstrated during the subsurface environmental monitoring of other CCS projects.

Validation and evaluation of common large-area display set (CLADS) performance specification

NASA Astrophysics Data System (ADS)

Hermann, David J.; Gorenflo, Ronald L.

1998-09-01

Battelle is under contract with Warner Robins Air Logistics Center to design a Common Large Area Display Set (CLADS) for use in multiple Command, Control, Communications, Computers, and Intelligence (C4I) applications that currently use 19- inch Cathode Ray Tubes (CRTs). Battelle engineers have built and fully tested pre-production prototypes of the CLADS design for AWACS, and are completing pre-production prototype displays for three other platforms simultaneously. With the CLADS design, any display technology that can be packaged to meet the form, fit, and function requirements defined by the Common Large Area Display Head Assembly (CLADHA) performance specification is a candidate for CLADS applications. This technology independent feature reduced the risk of CLADS development, permits life long technology insertion upgrades without unnecessary redesign, and addresses many of the obsolescence problems associated with COTS technology-based acquisition. Performance and environmental testing were performed on the AWACS CLADS and continues on other platforms as a part of the performance specification validation process. A simulator assessment and flight assessment were successfully completed for the AWACS CLADS, and lessons learned from these assessments are being incorporated into the performance specifications. Draft CLADS specifications were released to potential display integrators and manufacturers for review in 1997, and the final version of the performance specifications are scheduled to be released to display integrators and manufacturers in May, 1998. Initial USAF applications include replacements for the E-3 AWACS color monitor assembly, E-8 Joint STARS graphics display unit, and ABCCC airborne color display. Initial U.S. Navy applications include the E-2C ACIS display. For these applications, reliability and maintainability are key objectives. The common design will reduce the cost of operation and maintenance by an estimated 3.3M per year on E-3 AWACS alone. It is realistic to anticipate savings of over 30M per year as CLADS is implemented widely across DoD applications. As commonality and open systems interfaces begin to surface in DoD applications, the CLADS architecture can easily and cost effectively absorb the changes, and avoid COTS obsolescence issues.

Development of an engineering model traveling wave tube amplifier for space communication systems

NASA Technical Reports Server (NTRS)

Eallonardo, C. M.; Songli, J.; Basiulis, A.

1972-01-01

A design has been made of a 100 watt traveling-wave tube amplifier for use in space communication applications. The features of very high overall efficiency and heat rejection of waste heat at low thermal densities were predominant in the design concept. The design concept was proven by building a series of tubes, operating at efficiencies up to 50%. These tubes utilized heat pipe cooling and heat distribution such that 150 watts of waste heat was rejected at a density of less than 1.5 watts per square inch. A power supply to convert a 28 volt primary line of the needs of the TWT was built and operated at 85% efficiency.

Simulation and development of novel slow-wave structures for miniaturized THz-band vacuum-tube devices

NASA Astrophysics Data System (ADS)

Benedik, Andrey I.; Karetnikova, Tatiana A.; Torgashov, Roman A.; Terentyuk, Artem G.; Rozhnev, Andrey G.; Torgashov, Gennadiy V.; Ryskin, Nikita M.

2018-04-01

Microfabricated vacuum-tube millimeter- and THz-band sources are of great interest for numerous applications such as communications, radar, sensors, imaging, etc. Recently, miniaturized sheet-beam traveling-wave tubes for sub-THz and THz operation have attracted a considerable interest. In this paper, we present the results of modeling and development of slow-wave structures (SWS) for medium power (10-100 W) traveling-wave tube (TWT) amplifiers and backwardwave oscillators (BWO) in near-THz frequency band. Different types of SWSs are considered, such as double-vane SWS for TWT with a sheet electron beam, a folded-waveguide SWS, and novel planar SWSs on dielectric substrates.

Analysis and experimental study on the effect of a resonant tube on the performance of acoustic levitation devices

NASA Astrophysics Data System (ADS)

Jiang, Hai; Liu, Jianfang; Lv, Qingqing; Gu, Shoudong; Jiao, Xiaoyang; Li, Minjiao; Zhang, Shasha

2016-09-01

The influence of a resonant tube on the performance of acoustic standing wave-based levitation device (acoustic levitation device hereinafter) is studied by analyzing the acoustic pressure and levitation force of four types of acoustic levitation devices without a resonance tube and with resonance tubes of different radii R using ANSYS and MATLAB. Introducing a resonance tube either enhances or weakens the levitation strength of acoustic levitation device, depending on the resonance tube radii. Specifically, the levitation force is improved to a maximum degree when the resonance tube radius is slightly larger than the size of the reflector end face. Furthermore, the stability of acoustic levitation device is improved to a maximum degree by introducing a resonance tube of R=1.023λ. The experimental platform and levitation force measurement system of the acoustic levitation device with concave-end-face-type emitter and reflector are developed, and the test of suspended matters and liquid drops is conducted. Results show that the Φ6.5-mm steel ball is suspended easily when the resonance tube radius is 1.023λ, and the Φ5.5-mm steel ball cannot be suspended when the resonance tube radius is 1.251λ. The levitation capability of the original acoustic levitation device without a resonance tube is weakened when a resonance tube of R=1.251λ is applied. These results are consistent with the ANSYS simulation results. The levitation time of the liquid droplet with a resonance tube of R=1.023λ is longer than without a resonance tube. This result is also supported by the MATLAB simulation results. Therefore, the performance of acoustic levitation device can be improved by introducing a resonant tube with an appropriate radius.

Dynamic morphologies of pollen plastids visualised by vegetative-specific FtsZ1-GFP in Arabidopsis thaliana.

PubMed

Fujiwara, Makoto T; Hashimoto, Haruki; Kazama, Yusuke; Hirano, Tomonari; Yoshioka, Yasushi; Aoki, Seishiro; Sato, Naoki; Itoh, Ryuuichi D; Abe, Tomoko

2010-06-01

The behaviour and multiplication of pollen plastids have remained elusive despite their crucial involvement in cytoplasmic inheritance. Here, we present live images of plastids in pollen grains and growing tubes from transgenic Arabidopsis thaliana lines expressing stroma-localised FtsZ1-green-fluorescent protein fusion in a vegetative cell-specific manner. Vegetative cells in mature pollen contained a morphologically heterogeneous population of round to ellipsoidal plastids, whilst those in late-developing (maturing) pollen included plastids that could have one or two constriction sites. Furthermore, plastids in pollen tubes exhibited remarkable tubulation, stromule (stroma-filled tubule) extension, and back-and-forth movement along the direction of tube growth. Plastid division, which involves the FtsZ1 ring, was rarely observed in mature pollen grains.

Origami tubes with reconfigurable polygonal cross-sections.

PubMed

Filipov, E T; Paulino, G H; Tachi, T

2016-01-01

Thin sheets can be assembled into origami tubes to create a variety of deployable, reconfigurable and mechanistically unique three-dimensional structures. We introduce and explore origami tubes with polygonal, translational symmetric cross-sections that can reconfigure into numerous geometries. The tubular structures satisfy the mathematical definitions for flat and rigid foldability, meaning that they can fully unfold from a flattened state with deformations occurring only at the fold lines. The tubes do not need to be straight and can be constructed to follow a non-linear curved line when deployed. The cross-section and kinematics of the tubular structures can be reprogrammed by changing the direction of folding at some folds. We discuss the variety of tubular structures that can be conceived and we show limitations that govern the geometric design. We quantify the global stiffness of the origami tubes through eigenvalue and structural analyses and highlight the mechanical characteristics of these systems. The two-scale nature of this work indicates that, from a local viewpoint, the cross-sections of the polygonal tubes are reconfigurable while, from a global viewpoint, deployable tubes of desired shapes are achieved. This class of tubes has potential applications ranging from pipes and micro-robotics to deployable architecture in buildings.

Origami tubes with reconfigurable polygonal cross-sections

PubMed Central

Filipov, E. T.; Paulino, G. H.; Tachi, T.

2016-01-01

Thin sheets can be assembled into origami tubes to create a variety of deployable, reconfigurable and mechanistically unique three-dimensional structures. We introduce and explore origami tubes with polygonal, translational symmetric cross-sections that can reconfigure into numerous geometries. The tubular structures satisfy the mathematical definitions for flat and rigid foldability, meaning that they can fully unfold from a flattened state with deformations occurring only at the fold lines. The tubes do not need to be straight and can be constructed to follow a non-linear curved line when deployed. The cross-section and kinematics of the tubular structures can be reprogrammed by changing the direction of folding at some folds. We discuss the variety of tubular structures that can be conceived and we show limitations that govern the geometric design. We quantify the global stiffness of the origami tubes through eigenvalue and structural analyses and highlight the mechanical characteristics of these systems. The two-scale nature of this work indicates that, from a local viewpoint, the cross-sections of the polygonal tubes are reconfigurable while, from a global viewpoint, deployable tubes of desired shapes are achieved. This class of tubes has potential applications ranging from pipes and micro-robotics to deployable architecture in buildings. PMID:26997894

Nanosecond pulsed laser micromachining for experimental fatigue life study of Ti-3Al-2.5V tubes

NASA Astrophysics Data System (ADS)

Lin, Yaomin; Gupta, Mool C.; Taylor, Robert E.; Lei, Charles; Stone, William; Spidel, Tom; Yu, Michael; Williams, Reanne

2009-01-01

Defects on external surface of in-service hydraulic tubes can reduce total life cycles for operation. Evaluation of fatigue life of the tubes with damage is thus critical for safety reasons. A methodology of generating defects in the Ti-3Al-2.5V tube—a widely used pipeline in hydraulic systems of aircrafts—using nanosecond pulsed laser for experimental fatigue life study is described in this paper. Straight tubes of five different sizes were laser micromachined to generate notches of given length and depths on the outside surface. Approaches were developed to precisely control the notch dimensions. The laser-notched tubes were tested with cyclic internal impulse pressure and fatigue life was measured. The laser notches and fatigue cracks were characterized after the test. It is concluded that laser micromachining generated consistent notches, and the influence of notch depth on fatigue life of the tube is significant. Based on the experimental test results, the relationship between the fatigue life of the Ti-3Al-2.5V tube and the notch depth was revealed. The research demonstrated that laser micromachining is applicable for experimental fatigue life study of titanium tubes. The presented test data are useful for estimating the damage limits of the titanium tubes in service environment and for further theoretical studies.

Fumonisins, Tortillas and Neural Tube Defects: Untangling a Complex Issue

USDA-ARS?s Scientific Manuscript database

Fumonisin mycotoxins are found in corn and corn-based foods. Fumonisin B1 (FB1), the most common, disrupts sphingolipid metabolism thereby causing species-specific diseases in animals that include cancer in rodents and (birth) neural tube defects (NTD) in LM/Bc mice. Fumonisins’ affect on human heal...

Space power tubes - very much alive

NASA Technical Reports Server (NTRS)

Kosmahl, H. G.

1983-01-01

The application of the traveling wave tubes (TWT), the backbone of all civilian and military space communication programs, to past, present and future satellites is discussed. Performance characteristics and the trends and challenges in the future are reviewed. Finally, a comparison with Solid State devices, as derived from fundamental laws, is made and limitations discussed.

30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth...

30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth...

30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth...

30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth...

30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Brattice Cloth...

Sample Integrity Evaluation and EPA Method 325b Interlaboratory Comparison for Select Volatile Organic Compounds Collected Diffusively on Carbopack X Sorbent Tubes

EPA Science Inventory

Sample integrity evaluations and inter-laboratory comparisons were conducted in application of U.S. Environmental Protection Agency (EPA) Methods 325A/B for monitoring benzene and additional selected volatile organic compounds (VOCs) usingpassive-diffusive Carbopack X tube sample...

77 FR 47123 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses and Combined Licenses...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-07

...-Water Reactors] Steam Generator Tubes'' [Reference 7] and NEI [Nuclear Energy Institute] 97-06, ``Steam... CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared for these... the required structural margins of the SG tubes for both normal and accident conditions. Nuclear...

MICROBIAL SOLUTION: APPLICATION OF MICROORGANISMS FOR BIOFUEL PRODUCTION AND CO2 MITIGATION

EPA Science Inventory

A 100 L photobioreactor for biodiesel generation from microalga Chlorella vulgaris was constructed from two parallel clear PVC 10 feet tubes (6’ diameter) with a small slope (10%). The gas mixture (5% CO2 and air) flowed up the top of the PVC tubes from the bottom as...

Prediction of Forming Limit Diagram for Seamed Tube Hydroforming Based on Thickness Gradient Criterion

NASA Astrophysics Data System (ADS)

Chen, Xianfeng; Lin, Zhongqin; Yu, Zhongqi; Chen, Xinping; Li, Shuhui

2011-08-01

This study establishes the forming limit diagram (FLD) for QSTE340 seamed tube hydroforming by finite element method (FEM) simulation. FLD is commonly obtained from experiment, theoretical calculation and FEM simulation. But for tube hydroforming, both of the experimental and theoretical means are restricted in the application due to the equipment costs and the lack of authoritative theoretical knowledge. In this paper, a novel approach of predicting forming limit using thickness gradient criterion (TGC) is presented for seamed tube hydroforming. Firstly, tube bulge tests and uniaxial tensile tests are performed to obtain the stress-strain curve for tube three parts. Then one FE model for a classical tube free hydroforming and another FE model for a novel experimental apparatus by applying the lateral compression force and the internal pressure are constructed. After that, the forming limit strain is calculated based on TGC in the FEM simulation. Good agreement between the simulation and experimental results is indicated. By combining the TGC and FEM, an alternative way of predicting forming limit with enough accuracy and convenience is provided.

Development of a Compressor for a Miniature Pulse Tube Cryocooler of 2.5 W at 65 K for Telecommunication Applications

NASA Astrophysics Data System (ADS)

Matsumoto, N.; Yasukawa, Y.; Ohshima, K.; Takeuchi, T.; Matsushita, T.; Mizoguchi, Y.

2008-03-01

Fuji Electric Group has developed high-reliability technologies for various types of Stirling cryocoolers for space satellite systems. For commercial applications, we also have developed and marketed a miniature pulse-tube cryocooler providing 2W to 3W of refrigeration at 70K with 100W of electric power input. To improve efficiency and power density, we have developed a new moving-magnet linear motor to replace the moving-coil motor (which has only 70% efficiency) and have adopted a coaxial pulse-tube expander. This development is for cooling a high-temperature superconductive (HTS) device in a wireless telecommunication system. The compressor requires total compression work of 75W with 90% efficiency and a lifetime longer than 50,000 hours. At this point, the preliminary testing of each part of the moving magnet linear motor and the coaxial pulse tube has been completed. For the next phase, we constructed a first stage prototype compressor using the new linear motor, and tested the new machine. This paper describes the test results for the compressor.

Production Process of Biocompatible Magnesium Alloy Tubes Using Extrusion and Dieless Drawing Processes

NASA Astrophysics Data System (ADS)

Kustra, Piotr; Milenin, Andrij; Płonka, Bartłomiej; Furushima, Tsuyoshi

2016-06-01

Development of technological production process of biocompatible magnesium tubes for medical applications is the subject of the present paper. The technology consists of two stages—extrusion and dieless drawing process, respectively. Mg alloys for medical applications such as MgCa0.8 are characterized by low technological plasticity during deformation that is why optimization of production parameters is necessary to obtain good quality product. Thus, authors developed yield stress and ductility model for the investigated Mg alloy and then used the numerical simulations to evaluate proper manufacturing conditions. Grid Extrusion3d software developed by authors was used to determine optimum process parameters for extrusion—billet temperature 400 °C and extrusion velocity 1 mm/s. Based on those parameters the tube with external diameter 5 mm without defects was manufactured. Then, commercial Abaqus software was used for modeling dieless drawing. It was shown that the reduction in the area of 60% can be realized for MgCa0.8 magnesium alloy. Tubes with the final diameter of 3 mm were selected as a case study, to present capabilities of proposed processes.

Fluid-structure interaction and aerodynamics damping; Proceedings of the Tenth Biennial Conference on Mechanical Vibration and Noise, Cincinnati, OH, September 10-13, 1985

NASA Astrophysics Data System (ADS)

Dowell, E. H.; Au-Yang, M. K.

1985-09-01

The response of a two-layer elastic coating to pressure disturbances from a turbulent boundary layer is considered along with the application of the finite element method in the calculation of transmission loss of flat and curved panels, the application of various solution techniques to the calculation of transonic flutter boundaries, and noise transmission of double wall composite shells. Other topics explored are related to chaotic behavior of a simple single-degree-of-freedom system, the entrainment of self-sustained flow oscillations, the effects of strong shock loading on coupled bending-torssion flutter of tuned and mistuned cascades, and turbulent buffeting of a multispan tube bundle. Attention is given to the dynamics of heat exchangers U-bend tubes with flat bar supports, a review of flow induced vibration of two circular cylinders in crossflow, the avoidance of leakage flow-induced vibration by a tube-in-tube slip joint, random load from multiple sources and its assessment, and wake-induced vibration of a conductor in the wake of another via a 3-D finite element method.

Laser for high frequency modulated interferometry

DOEpatents

Mansfield, D.K.; Vocaturo, M.; Guttadora, L.J.

1991-07-23

A Stark-tuned laser operating in the 119 micron line of CH[sub 3]OH has an output power of several tens of milliwatts at 30 Watts of pump power while exhibiting a doublet splitting of about ten MHz with the application of a Stark field on the order of 500 volts/cm. This output power allows for use of the laser in a multi-channel interferometer, while its high operating frequency permits the interferometer to measure rapid electron density changes in a pellet injected or otherwise fueled plasma such as encountered in magnetic fusion devices. The laser includes a long far-infrared (FIR) pyrex resonator tube disposed within a cylindrical water jacket and incorporating charged electrodes for applying the Stark field to a gas confined therein. With the electrodes located within the resonator tube, the resonator tube walls are cooled by a flowing coolant without electrical breakdown in the coolant liquid during application of the Stark field. Wall cooling allows for substantially increased FIR output powers. Provision is made for introducing a buffer gas into the resonator tube for increasing laser output power and its operating bandwidth. 10 figures.

Laser for high frequency modulated interferometry

DOEpatents

Mansfield, Dennis K.; Vocaturo, Michael; Guttadora, Lawrence J.

1991-01-01

A Stark-tuned laser operating in the 119 micron line of CH.sub.3 OH has an output power of several tens of milliwatts at 30 Watts of pump power while exhibiting a doublet splitting of about ten MHz with the application of a Stark field on the order of 500 volts/cm. This output power allows for use of the laser in a multi-channel interferometer, while its high operating frequency permits the interferometer to measure rapid electron density changes in a pellet injected or otherwise fueled plasma such as encountered in magnetic fusion devices. The laser includes a long far-infrared (FIR) pyrex resonator tube disposed within a cylindrical water jacket and incorporating charged electrodes for applying the Stark field to a gas confined therein. With the electrodes located within the resonator tube, the resonator tube walls are cooled by a flowing coolant without electrical breakdown in the coolant liquid during application of the Stark field. Wall cooling allows for substantially increased FIR output powers. Provision is made for introducing a buffer gas into the resonator tube for increasing laser output power and its operating bandwidth.

Miniplate with a bendable C-tube head allows the clinician to alter biomechanical advantage without physically moving the skeletal anchorage device.

PubMed

Seo, Kyung-Won; Ahn, Hyo-Won; Kim, Seong-Hun; Chung, Kyu-Rhim; Nelson, Gerald

2014-01-01

This article introduces a binary function of a miniplate with a bendable C-tube head used in corticotomy-assisted segment intrusion. The advantage of the device is that the point of force application can be altered without having to move the miniplate or place an additional anchorage device. Cases for this study were selected from patients who received perisegmental corticotomy with compression osteogenesis (Speedy Surgical Orthodontics) for segmental intrusion. For the skeletal anchorage on patients who received Speedy Surgical Orthodontics for posterior segment intrusion to improve on severe open bite correction, the C-tube was placed on the buccal wall of the maxilla for traction of orthopedic force as a temporary skeletal anchorage. The C-tube head portion is made with titanium grade II, which makes bending easy with a Weingart plier. This adjustment regains distance and range needed to continue intrusion of posterior segment. As an alternative to orthognathic surgery to correct a severe open bite, perisegmental corticotomy combined with orthopedic force application from a temporary skeletal anchorage device can be used. The corticotomy-assisted segment intrusion is a 2-stage procedure: first, the corticotomy is performed in the palate and 2 weeks later in the buccal alveolus. A C-plate was placed in the midpalatal area, and a C-tube was placed apical to the buccal corticotomy site. Elastics were used with orthopedic forces to induce compression osteogenesis. As the intrusion took place, the elastic stretched, and resultant force and range in the buccal segment decreased. The C-tube head was adjusted by bending to gain more distance, reviving the elastic force on the posterior segment until desired intrusion was accomplished. The miniplate with a bendable C-tube head serves for temporary skeletal anchorage of orthopedic traction force to achieve segmental intrusion and has the advantage that the bendable head can be adjusted to improve the force application for intrusion without having to move or place another temporary skeletal anchorage device.

Boiler Tube Corrosion Characterization with a Scanning Thermal Line

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Jacobstein, Ronald; Reilly, Thomas

2001-01-01

Wall thinning due to corrosion in utility boiler water wall tubing is a significant operational concern for boiler operators. Historically, conventional ultrasonics has been used for inspection of these tubes. Unfortunately, ultrasonic inspection is very manpower intense and slow. Therefore, thickness measurements are typically taken over a relatively small percentage of the total boiler wall and statistical analysis is used to determine the overall condition of the boiler tubing. Other inspection techniques, such as electromagnetic acoustic transducer (EMAT), have recently been evaluated, however they provide only a qualitative evaluation - identifying areas or spots where corrosion has significantly reduced the wall thickness. NASA Langley Research Center, in cooperation with ThermTech Services, has developed a thermal NDE technique designed to quantitatively measure the wall thickness and thus determine the amount of material thinning present in steel boiler tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source coupled with the analysis technique represents a significant improvement in the inspection speed and accuracy for large structures such as boiler water walls. A theoretical basis for the technique will be presented to establish the quantitative nature of the technique. Further, a dynamic calibration system will be presented for the technique that allows the extraction of thickness information from the temperature data. Additionally, the results of the application of this technology to actual water wall tubing samples and in-situ inspections will be presented.

Healing of broken multiwalled carbon nanotubes using very low energy electrons in SEM: a route toward complete recovery.

PubMed

Kulshrestha, Neha; Misra, Abhishek; Hazra, Kiran Shankar; Roy, Soumyendu; Bajpai, Reeti; Mohapatra, Dipti Ranjan; Misra, D S

2011-03-22

We report the healing of electrically broken multiwalled carbon nanotubes (MWNTs) using very low energy electrons (3-10 keV) in scanning electron microscopy (SEM). Current-induced breakdown caused by Joule heating has been achieved by applying suitably high voltages. The broken tubes were examined and exposed to electrons of 3-10 keV in situ in SEM with careful maneuvering of the electron beam at the broken site, which results in the mechanical joining of the tube. Electrical recovery of the same tube has been confirmed by performing the current-voltage measurements after joining. This easy approach is directly applicable for the repairing of carbon nanotubes incorporated in ready devices, such as in on-chip horizontal interconnects or on-tip probing applications, such as in scanning tunneling microscopy.

Generation of low-emittance electron beams in electrostatic accelerators for FEL applications

NASA Astrophysics Data System (ADS)

Chen, Teng; Elias, Luis R.

1995-02-01

This paper reports results of transverse emittance studies and beam propagation in electrostatic accelerators for free electron laser applications. In particular, we discuss emittance growth analysis of a low current electron beam system consisting of a miniature thermoionic electron gun and a National Electrostatics Accelerator (NEC) tube. The emittance growth phenomenon is discussed in terms of thermal effects in the electron gun cathode and aberrations produced by field gradient changes occurring inside the electron gun and throughout the accelerator tube. A method of reducing aberrations using a magnetic solenoidal field is described. Analysis of electron beam emittance was done with the EGUN code. Beam propagation along the accelerator tube was studied using a cylindrically symmetric beam envelope equation that included beam self-fields and the external accelerator fields which were derived from POISSON simulations.

Formation of droplet interface bilayers in a Teflon tube

NASA Astrophysics Data System (ADS)

Walsh, Edmond; Feuerborn, Alexander; Cook, Peter R.

2016-09-01

Droplet-interface bilayers (DIBs) have applications in disciplines ranging from biology to computing. We present a method for forming them manually using a Teflon tube attached to a syringe pump; this method is simple enough it should be accessible to those without expertise in microfluidics. It exploits the properties of interfaces between three immiscible liquids, and uses fluid flow through the tube to pack together drops coated with lipid monolayers to create bilayers at points of contact. It is used to create functional nanopores in DIBs composed of phosphocholine using the protein α-hemolysin (αHL), to demonstrate osmotically-driven mass transfer of fluid across surfactant-based DIBs, and to create arrays of DIBs. The approach is scalable, and thousands of DIBs can be prepared using a robot in one hour; therefore, it is feasible to use it for high throughput applications.

New diffuser/applicator for use in the treatment of esophageal cancer by photodynamic therapy

NASA Astrophysics Data System (ADS)

Hudson, Emma J.; Stringer, Mark R.; Dixon, Kate; Moghissi, Keyvan

1995-03-01

We have designed and constructed a simple, cheap and effective diffuser/applicator for intraluminal photodynamic therapy in oesophageal cancer. A cylindrical diffusing optical fiber can be easily located in the center of the oesophageal lumen with the use of a modified naso- gastric Ryles tube. This allows more uniform illumination of the luminal circumference. Measurements are presented of the light field generated by this delivery system in an optical phantom. These demonstrate that the presence of the Ryles tube imposes only a small modification on the output of the bare diffuser. The light doses received adjacent to the diffusing section are identical, within the accuracy of measurement, both with and without the tube. This ensures adequate illumination of a circumferential oesophageal tumor using a contained fiber, without adjustment of the established treatment parameters.

Development of tube-packaged FBG strain sensor and application in the vibration experiment of submarine pipeline model

NASA Astrophysics Data System (ADS)

Ren, Liang; Li, Hong-Nan; Sun, Li; Li, Dong-Sheng

2005-05-01

Optical fiber sensors have received increasing attention in the fields of aeronautic and civil engineering for their superior ability of explosion proof, immunity to electromagnetic interference and high accuracy, especially fitting for measurement applications in harsh environment. In this paper, a novel FBG (fiber Bragg grating) strain sensor, which was packaged in a 1.2mm stainless steel tube by epoxy resin, was developed. Experiments were conducted on the universal material testing machine to calibrate its strain transferring characteristics. The sensor has the advantages of small size, high precision and flexible use, and demonstrates promising potentials. Ten of tube-packaged strain FBG sensors were applied in the vibration experiment of submarine pipeline model. The strain measured by FBG sensor agrees well with the electric resistance strain sensor.

Development of tube-packaged FBG strain sensor and application in the vibration experiment of submarine pipeline model

NASA Astrophysics Data System (ADS)

Ren, Liang; Li, Hong-Nan; Sun, Li; Li, Dong-Sheng

2005-02-01

Optical fiber sensors have received increasing attention in the fields of aeronautic and civil engineering for their superior ability of explosion proof, immunity to electromagnetic interference and high accuracy, especially fitting for measurement applications in harsh environment. In this paper, a novel FBG (fiber Bragg grating) strain sensor, which was packaged in a 1.2mm stainless steel tube by epoxy resin, was developed. Experiments were conducted on the universal material testing machine to calibrate its strain transferring characteristics. The sensor has the advantages of small size, high precision and flexible use, and demonstrates promising potentials. Ten of tube-packaged strain FBG sensors were applied in the vibration experiment of submarine pipeline model. The strain measured by FBG sensor agrees well with the electric resistance strain sensor.

Spatial Power Combining Amplifier for Ground and Flight Applications

NASA Astrophysics Data System (ADS)

Velazco, J. E.; Taylor, M.

2016-11-01

Vacuum-tube amplifiers such as klystrons and traveling-wave tubes are the workhorses of high-power microwave radiation generation. At JPL, vacuum tubes are extensively used in ground and flight missions for radar and communications. Vacuum tubes use electron beams as the source of energy to achieve microwave power amplification. Such electron beams operate at high kinetic energies and thus require high voltages to function. In addition, vacuum tubes use compact cavity and waveguide structures that hold very intense radio frequency (RF) fields inside. As the operational frequency is increased, the dimensions of these RF structures become increasingly smaller. As power levels and operational frequencies are increased, the highly intense RF fields inside of the tubes' structures tend to arc and create RF breakdown. In the case of very high-power klystrons, electron interception - also known as body current - can produce thermal runaway of the cavities that could lead to the destruction of the tube. The high voltages needed to power vacuum tubes tend to require complicated and cumbersome power supplies. Consequently, although vacuum tubes provide unmatched high-power microwaves, they tend to arc, suffer from thermal issues, and require failure-prone high-voltage power supplies. In this article, we present a new concept for generating high-power microwaves that we refer to as the Spatial Power Combining Amplifier (SPCA). The SPCA is very compact, requires simpler, lower-voltage power supplies, and uses a unique power-combining scheme wherein power from solid-state amplifiers is coherently combined. It is a two-port amplifier and can be used inline as any conventional two-port amplifier. It can deliver its output power to a coaxial line, a waveguide, a feed, or to any microwave load. A key feature of this new scheme is the use of higher-order-mode microwave structures to spatially divide and combine power. Such higher-order-mode structures have considerably larger cross-sections than comparable klystrons and traveling-wave tube counterparts and thus avoid RF breakdown and thermal issues common to vacuum tubes. We present a basic description of the SPCA mechanism and initial results of an S-band (2.4 GHz) 100-W, 45-dB gain SPCA prototype. We also discuss future X-band (8.4 GHz), Ka-band (32 GHz), and W-band (94 GHz) SPCA designs for both radar and communications applications.

Application of laser-based profilometry to tubing in power generating utilities

NASA Astrophysics Data System (ADS)

Doyle, James L.

1995-05-01

Over the past several years lasers have been employed in an ever widening number of applications in an incredibly diverse set of markets. In the area of nondestructive testing, however, laser-based systems have only recently made inroads into the commercial markets. About ten years ago QUEST Integrated, Inc., began working with the U.S. Navy to adapt the principal of laser triangulation to solve a serious maintenance related problem. The internal surfaces of marine boiler tubes were experiencing pitting and corrosion which had resulted in catastrophic shipboard failures. At that time, conventional visual methods only allowed operators to inspect the first eighteen inches of the tube using a rigid borescope. If any pits were located, a mechanical stylus mechanism was used to obtain an approximate depth measurement of the pit. The condition of the balance of the tube was then extrapolated based on this extremely limited amount of information. Often the worst pitting was found in the bends of the tube, which could not be inspected by the visual method. Finally, a catastrophic boiler failure on an aircraft carrier resulted in the initiation of a search by the U.S. Navy for a better solution. Quest was contracted to develop an articulated probe which could negotiate the full length of a boiler tube with multiple bends, and generate a complete digital map of the inside surface. A key requirement of this probe would be rapid and quantitative measurement of internal features such as ID pits and corrosion. In 1987 QUEST delivered the first laser- optic tube inspection system to the U.S. Navy for use in marine boiler tubes. The Laser Optic Tube Inspection System (LOTISTM) was immediately put to use and paid for itself many times over in reduced maintenance costs. Over the next six years several generations of LOTIS were developed for the U.S. Navy, each one providing more capabilities, improved inspection speeds, and more user friendly operator interface. Today, LOTIS is used for routine inspections on marine boiler tubes by the U.S. Navy, with units located in several parts of the United States and overseas. In 1993 QUEST began exploring the possibility of extending this technology to the inspection of commercial tubes used in power generation and chemical processing. The following is an overview of the use of laser profilometry for nondestructive testing.

Comparison of conventional and novel quadrupole drift tube magnets inspired by Klaus Halbach

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

Feinberg, B.

1995-02-01

Quadrupole drift tube magnets for a heavy-ion linac provide a demanding application of magnet technology. A comparison is made of three different solutions to the problem of providing an adjustable high-field-strength quadrupole magnet in a small volume. A conventional tape-wound electromagnet quadrupole magnet (conventional) is compared with an adjustable permanent-magnet/iron quadrupole magnet (hybrid) and a laced permanent-magnet/iron/electromagnet (laced). Data is presented from magnets constructed for the SuperHILAC heavy-ion linear accelerator, and conclusions are drawn for various applications.

Picometre and nanoradian heterodyne interferometry and its application in dilatometry and surface metrology

NASA Astrophysics Data System (ADS)

Schuldt, T.; Gohlke, M.; Kögel, H.; Spannagel, R.; Peters, A.; Johann, U.; Weise, D.; Braxmaier, C.

2012-05-01

A high-sensitivity heterodyne interferometer implementing differential wavefront sensing for tilt measurement was developed over the last few years. With this setup, using an aluminium breadboard and compact optical mounts with a beam height of 2 cm, noise levels less than 5 pm Hz-1/2 in translation and less than 10 nrad Hz-1/2 in tilt measurement, both for frequencies above 10-2 Hz, have been demonstrated. Here, a new, compact and ruggedized interferometer setup utilizing a baseplate made of Zerodur, a thermally and mechanically highly stable glass ceramic with a coefficient of thermal expansion (CTE) of 2 × 10-8 K-1, is presented. The optical components are fixed to the baseplate using a specifically developed, easy-to-handle, assembly-integration technology based on a space-qualified two-component epoxy. While developed as a prototype for future applications aboard satellite space missions (such as Laser Interferometer Space Antenna), the interferometer is used in laboratory experiments for dilatometry and surface metrology. A first dilatometer setup with a demonstrated accuracy of 10-7 K-1 in CTE measurement was realized. As it was seen that the accuracy is limited by the dimensional stability of the sample tube support, a new setup was developed utilizing Zerodur as structural material for the sample tube support. In another activity, the interferometer is used for characterization of high-quality mirror surfaces at the picometre level and for high-accuracy two-dimensional surface characterization in a prototype for industrial applications. In this paper, the corresponding designs, their realizations and first measurements of both applications in dilatometry and surface metrology are presented.

Tuberculosis Screening by Tuberculosis Skin Test or QuantiFERON®-TB Gold In-Tube Assay among an Immigrant Population with a High Prevalence of Tuberculosis and BCG Vaccination

PubMed Central

Painter, John A.; Graviss, Edward A.; Hai, Hoang Hoa; Nhung, Duong Thi Cam; Nga, Tran Thi Thanh; Ha, Ngan P.; Wall, Kirsten; Loan, Le Thien Huong; Parker, Matt; Manangan, Lilia; O’Brien, Rick; Maloney, Susan A.; Hoekstra, R. M.; Reves, Randall

2013-01-01

Rationale Each year 1 million persons acquire permanent U.S. residency visas after tuberculosis (TB) screening. Most applicants undergo a 2-stage screening with tuberculin skin test (TST) followed by CXR only if TST-positive at > 5 mm. Due to cross reaction with bacillus Calmette-Guérin (BCG), TST may yield false positive results in BCG-vaccinated persons. Interferon gamma release assays exclude antigens found in BCG. In Vietnam, like most high TB-prevalence countries, there is universal BCG vaccination at birth. Objectives 1. Compare the sensitivity of QuantiFERON ®-TB Gold In-Tube Assay (QFT) and TST for culture-positive pulmonary TB. 2. Compare the age-specific and overall prevalence of positive TST and QFT among applicants with normal and abnormal CXR. Methods We obtained TST and QFT results on 996 applicants with abnormal CXR, of whom 132 had TB, and 479 with normal CXR. Results The sensitivity for tuberculosis was 86.4% for QFT; 89.4%, 81.1%, and 52.3% for TST at 5, 10, and 15 mm. The estimated prevalence of positive results at age 15–19 years was 22% and 42% for QFT and TST at 10 mm, respectively. The prevalence increased thereafter by 0.7% year of age for TST and 2.1% for QFT, the latter being more consistent with the increase in TB among applicants. Conclusions During 2-stage screening, QFT is as sensitive as TST in detecting TB with fewer requiring CXR and being diagnosed with LTBI. These data support the use of QFT over TST in this population.  PMID:24367546

Scale-Up Method for the Shock Compaction of Powders

NASA Astrophysics Data System (ADS)

Carton, E. P.; Stuivinga, M.

2004-07-01

Shock wave compaction in the cylindrical configuration lends itself to be scaled-up for small-scale industrial applications. While scaling up in the axial direction is easy, scaling up in the lateral direction is less straightforward and may lead to cracks in the center. A different scale up method is presented here; aluminum tubes are filled with the powder to be compacted and placed in a circle inside a large metal tube, with a metal shock wave reflector in the center. The space in between is filled with an inert powder medium: alumina, salt or sand. It is found that salt is the best medium for the integrity of the aluminum tube and for the ease of removal of the aluminum tube out of the (densified) powder medium. Experimental results of (slightly ellipsoidal) shock compacted tubes that are produced this way are shown as an example. In the case of B4C, after infiltration with the aluminum of the tube, fully dense cermet compacts without any cracks are thus produced, batch by batch.

Large, high resolution integrating TV sensor for astronomical appliations

NASA Technical Reports Server (NTRS)

Spitzer, L. J.

1977-01-01

A magnetically focused SEC tube developed for photometric applications is described. Efforts to design a 70 mm version of the tube which meets the ST f/24 camera requirements of the space telescope are discussed. The photometric accuracy of the 70 mm tube is executed to equal that of the previously developed 35 mm tube. The tube meets the criterion of 50 percent response at 20 cycles/mm in the central region of the format, and, with the removal of the remaining magnetic parts, this spatial frequency is expected over almost all of the format. Since the ST f/24 camera requires sensitivity in the red as well as the ultraviolet and visible spectra, attempts were made to develop tubes with this ability. It was found that it may be necessary to choose between red and u.v. sensitivity and tradeoff red sensitivity for low background. Results of environmental tests indicate no substantive problems in utilizing it in a flight camera system that will meet the space shuttle launch requirements.

Innovative phase shifter for pulse tube operating below 10 K

NASA Astrophysics Data System (ADS)

Duval, Jean-Marc; Charles, Ivan; Daniel, Christophe; André, Jérôme

2016-09-01

Stirling type pulse tubes are classically based on the use of an inertance phase shifter to optimize their cooling power. The limitations of the phase shifting capabilities of these inertances have been pointed out in various studies. These limitations are particularly critical for low temperature operation, typically below about 50 K. An innovative phase shifter using an inertance tube filled with liquid, or fluid with high density or low viscosity, and separated by a sealed metallic diaphragm has been conceived and tested. This device has been characterized and validated on a dedicated test bench. Operation on a 50-80 K pulse tube cooler and on a low temperature (below 8 K) pulse tube cooler have been demonstrated and have validated the device in operation. These developments open the door for efficient and compact low temperature Stirling type pulse tube coolers. The possibility of long life operation has been experimentally verified and a design for space applications is proposed.

High-Throughput Top-Down and Bottom-Up Processes for Forming Single-Nanotube Based Architectures for 3D Electronics

NASA Technical Reports Server (NTRS)

Kaul, Anupama B.; Megerian, Krikor G.; von Allmen, Paul; Kowalczyk, Robert; Baron, Richard

2009-01-01

We have developed manufacturable approaches to form single, vertically aligned carbon nanotubes, where the tubes are centered precisely, and placed within a few hundred nm of 1-1.5 micron deep trenches. These wafer-scale approaches were enabled by chemically amplified resists and inductively coupled Cryo-etchers for forming the 3D nanoscale architectures. The tube growth was performed using dc plasma-enhanced chemical vapor deposition (PECVD), and the materials used for the pre-fabricated 3D architectures were chemically and structurally compatible with the high temperature (700 C) PECVD synthesis of our tubes, in an ammonia and acetylene ambient. Tube characteristics were also engineered to some extent, by adjusting growth parameters, such as Ni catalyst thickness, pressure and plasma power during growth. Such scalable, high throughput top-down fabrication techniques, combined with bottom-up tube synthesis, should accelerate the development of PECVD tubes for applications such as interconnects, nano-electromechanical (NEMS), sensors or 3D electronics in general.

Innovative Application of a Microlaryngeal Surgery Tube for difficult Airway Management in a Case of Down's Syndrome.

PubMed

Gulabani, Michell; Gupta, Akhilesh; Bannerjee, Neerja Gaur; Sood, Rajesh; Dass, Prashant

2016-04-01

An 11-year-old male child, known case of down's syndrome with congenital oesophageal stricture was posted for oesophageal dilatation. Preoperative airway assessment revealed a high arched palate, receding mandible and Mallampati Score of 2. During surgery, after loss of consciousness which was described as loss of eyelash reflex and adequate jaw relaxation, direct laryngoscopy and endotracheal intubation was attempted with a cuffed endotracheal tube number 5.0mm ID (internal diameter). The endotracheal tube could not be negotiated smoothly, so 5.0mm ID uncuffed endotracheal tube was used which passed through easily, but on auscultation revealed a significant leak. Later, intubation via a Micro Laryngeal Surgery (MLS) cuffed tube 4.0mm ID was attempted. The MLS tube advanced smoothly and there was no associated leak on positive pressure ventilation. Thus by innovative thinking and avant-garde reasoning, a definitive airway device could be positioned with no other suitable alternative at hand.

Tube-Load Model Parameter Estimation for Monitoring Arterial Hemodynamics

PubMed Central

Zhang, Guanqun; Hahn, Jin-Oh; Mukkamala, Ramakrishna

2011-01-01

A useful model of the arterial system is the uniform, lossless tube with parametric load. This tube-load model is able to account for wave propagation and reflection (unlike lumped-parameter models such as the Windkessel) while being defined by only a few parameters (unlike comprehensive distributed-parameter models). As a result, the parameters may be readily estimated by accurate fitting of the model to available arterial pressure and flow waveforms so as to permit improved monitoring of arterial hemodynamics. In this paper, we review tube-load model parameter estimation techniques that have appeared in the literature for monitoring wave reflection, large artery compliance, pulse transit time, and central aortic pressure. We begin by motivating the use of the tube-load model for parameter estimation. We then describe the tube-load model, its assumptions and validity, and approaches for estimating its parameters. We next summarize the various techniques and their experimental results while highlighting their advantages over conventional techniques. We conclude the review by suggesting future research directions and describing potential applications. PMID:22053157

On the Lateral Compressive Behavior of Empty and Ex-Situ Aluminum Foam-Filled Tubes at High Temperature

PubMed Central

Movahedi, Nima; Marsavina, Liviu

2018-01-01

In this research work, the effect of lateral loading (LL) on the crushing performance of empty tubes (ETs) and ex situ aluminum foam-filled tubes (FFTs) was investigated at 300 °C. The cylindrical thin-walled steel tube was filled with the closed-cell aluminum alloy foam that compressed under quasi-static loading conditions. During the compression test, the main mechanical properties of the ETs improved due to the interaction effect between the cellular structure of the foam and the inner wall of the empty tube. In addition, the initial propagated cracks on the steel tubes reduced considerably as a result of such interaction. Furthermore, the obtained results of the LL loading were compared with the axial loading (AL) results for both ETs and FFTs at the same temperature. The findings indicated that the application of loading on the lateral surface of the composite causes the lower mechanical properties of both ETs and FFTs in comparison with the axial loading conditions. PMID:29617300

Heat exchanger for reactor core and the like

DOEpatents

Kaufman, Jay S.; Kissinger, John A.

1986-01-01

A compact bayonet tube type heat exchanger which finds particular application as an auxiliary heat exchanger for transfer of heat from a reactor gas coolant to a secondary fluid medium. The heat exchanger is supported within a vertical cavity in a reactor vessel intersected by a reactor coolant passage at its upper end and having a reactor coolant return duct spaced below the inlet passage. The heat exchanger includes a plurality of relatively short length bayonet type heat exchange tube assemblies adapted to pass a secondary fluid medium therethrough and supported by primary and secondary tube sheets which are releasibly supported in a manner to facilitate removal and inspection of the bayonet tube assemblies from an access area below the heat exchanger. Inner and outer shrouds extend circumferentially of the tube assemblies and cause the reactor coolant to flow downwardly internally of the shrouds over the tube bundle and exit through the lower end of the inner shroud for passage to the return duct in the reactor vessel.

Improved immunomagnetic enrichment of CD34(+) cells from umbilical cord blood using the CliniMACS cell separation system.

PubMed

Blake, Joseph M; Nicoud, Ian B; Weber, Daniel; Voorhies, Howard; Guthrie, Katherine A; Heimfeld, Shelly; Delaney, Colleen

2012-08-01

CD34(+) enrichment from cord blood units (CBU) is used increasingly in clinical applications involving ex vivo expansion. The CliniMACS instrument from Miltenyi Biotec is a current good manufacturing practice (cGMP) immunomagnetic selection system primarily designed for processing larger numbers of cells: a standard tubing set (TS) can process a maximum of 60 billion cells, while the larger capacity tubing set (LS) will handle 120 billion cells. In comparison, most CBU contain only 1-2 billion cells, raising a question regarding the optimal tubing set for CBU CD34(+) enrichment. We compared CD34(+) cell recovery and overall viability after CliniMACS processing of fresh CBU with either TS or LS. Forty-six freshly collected CBU (≤ 36 h) were processed for CD34(+) enrichment; 22 consecutive units were selected using TS and a subsequent 24 processed with LS. Cell counts and immunophenotyping were performed pre- and post-selection to assess total nucleated cells (TNC), viability and CD34(+) cell content. Two-sample t-tests of mean CD34(+) recovery and viability revealed significant differences in favor of LS (CD34(+) recovery, LS = 56%, TS = 45%, P = 0.003; viability, LS = 74%, TS = 59%, P = 0.011). Stepwise linear regression, considering pre-processing unit age, viability, TNC and CD34(+) purity, demonstrated statistically significant correlations only with the tubing set used and age of unit. For CD34(+) enrichment from fresh CBU, LS provided higher post-selection viability and more efficient recovery. In this case, a lower maximum TNC specification of TS was not predictive of better performance. The same may hold for smaller scale enrichment of other cell types with the CliniMACS instrument.

Tube Maps for Effective Geoscience Career Planning and Development

NASA Astrophysics Data System (ADS)

Keane, C. M.; Wilson, C. E.; Houlton, H. R.

2013-12-01

One of the greatest challenges faced by students and new graduates is the advice that they must take charge of their own career planning. This is ironic as new graduates are least prepared to understand the full spectrum of options and the potential pathways to meeting their personal goals. We will examine the rationale, tools, and utility of an approach aimed at assisting individuals in career planning nicknamed a "tube map." In particular, this approach has been used in support of geoscientist recruitment and career planning in major European energy companies. By utilizing information on the occupational sequences of geoscience professionals within an organization or a community, a student or new hire can quickly understand the proven pathways towards their eventual career goals. The tube map visualizes the career pathways of individuals in the form of a subway map, with specific occupations represented as "stations" and pathway interconnections represented as "transfers." The major application of this approach in the energy sector was to demonstrate both the logical career pathways to either senior management or senior technical positions, as well as present the reality that time must be invested in "lower level" jobs, thereby nullifying a persistent overinflated sense of the speed of upward mobility. To this end, we have run a similar occupational analysis on several geoscience employers, including one with somewhat non-traditional geoscience positions and another that would be considered a very traditional employer. We will examine the similarities and differences between the resulting 'tube maps,' critique the tools used to create the maps, and assess the utility of the product in career development planning for geoscience students and new hires.

Theory and computation of non-RRKM lifetime distributions and rates in chemical systems with three or more degrees of freedom

NASA Astrophysics Data System (ADS)

Gabern, Frederic; Koon, Wang S.; Marsden, Jerrold E.; Ross, Shane D.

2005-11-01

The computation, starting from basic principles, of chemical reaction rates in realistic systems (with three or more degrees of freedom) has been a longstanding goal of the chemistry community. Our current work, which merges tube dynamics with Monte Carlo methods provides some key theoretical and computational tools for achieving this goal. We use basic tools of dynamical systems theory, merging the ideas of Koon et al. [W.S. Koon, M.W. Lo, J.E. Marsden, S.D. Ross, Heteroclinic connections between periodic orbits and resonance transitions in celestial mechanics, Chaos 10 (2000) 427-469.] and De Leon et al. [N. De Leon, M.A. Mehta, R.Q. Topper, Cylindrical manifolds in phase space as mediators of chemical reaction dynamics and kinetics. I. Theory, J. Chem. Phys. 94 (1991) 8310-8328.], particularly the use of invariant manifold tubes that mediate the reaction, into a tool for the computation of lifetime distributions and rates of chemical reactions and scattering phenomena, even in systems that exhibit non-statistical behavior. Previously, the main problem with the application of tube dynamics has been with the computation of volumes in phase spaces of high dimension. The present work provides a starting point for overcoming this hurdle with some new ideas and implements them numerically. Specifically, an algorithm that uses tube dynamics to provide the initial bounding box for a Monte Carlo volume determination is used. The combination of a fine scale method for determining the phase space structure (invariant manifold theory) with statistical methods for volume computations (Monte Carlo) is the main contribution of this paper. The methodology is applied here to a three degree of freedom model problem and may be useful for higher degree of freedom systems as well.

Surface applicator of a miniature X-ray tube for superficial electronic brachytherapy of skin cancer.

PubMed

Kim, Hyun Nam; Lee, Ju Hyuk; Park, Han Beom; Kim, Hyun Jin; Cho, Sung Oh

2018-01-01

We designed and fabricated a surface applicator of a novel carbon nanotube (CNT)-based miniature X-ray tube for the use in superficial electronic brachytherapy of skin cancer. To investigate the effectiveness of the surface applicator, the performance of the applicator was numerically and experimentally analyzed. The surface applicator consists of a graphite flattening filter and an X-ray shield. A Monte Carlo radiation transport code, MCNP6, was used to optimize the geometries of both the flattening filter and the shield so that X-rays are generated uniformly over the desired region. The performance of the graphite filter was compared with that of conventional aluminum (Al) filters of different geometries using the numerical simulations. After fabricating a surface applicator, the X-ray spatial distribution was measured to evaluate the performance of the applicator. The graphite filter shows better spatial dose uniformity and less dose distortion than Al filters. Moreover, graphite allows easy fabrication of the flattening filter due to its low X-ray attenuation property, which is particularly important for low-energy electronic brachytherapy. The applicator also shows that no further X-ray shielding is required for the application because unwanted X-rays are completely protected. As a result, highly uniform X-ray dose distribution was achieved from the miniature X-ray tube mounted with the surface applicators. The measured values of both flatness and symmetry were less than 5% and the measured penumbra values were less than 1 mm. All these values satisfy the currently accepted tolerance criteria for radiation therapy. The surface applicator exhibits sufficient performance capability for their application in electronic brachytherapy of skin cancers. © 2017 American Association of Physicists in Medicine.

Nursing administration of medication via enteral tubes in adults: a systematic review.

PubMed

Phillips, Nicole M; Nay, Rhonda

Enteral tubes are frequently inserted as part of medical treatment in a wide range of patient situations. Patients with an enteral tube are cared for by nurses in a variety of settings, including general and specialised acute care areas, aged care facilities and at home. Regardless of the setting, nurses have the primary responsibility for administering medication through enteral tubes. Medication administration via an enteral tube is a reasonably common nursing intervention that entails a number of skills, including preparing the medication, verifying the tube position, flushing the tube and assessing for potential complications. If medications are not given effectively through an enteral tube, harmful consequences may result leading to increased morbidity, for example, tube occlusion, diarrhoea and aspiration pneumonia. There are resultant costs for the health-care system related to possible increased length of stay and increased use of equipment. Presently what is considered to be best practice to give medications through enteral tubes is unknown. The objective of this systematic review was to determine the best available evidence on which nursing interventions are effective in minimising the complications associated with the administration of medications via enteral tubes in adults. Nursing interventions and considerations related to medication administration included form of medication, verifying tube placement before administration, methods used to give medication, methods used to flush tubes, maintenance of tube patency and specific practices to prevent possible complications related to the administration of enteral medications. The following databases were searched for literature reported in English only: CINAHL, MEDLINE, The Cochrane Library, Current Contents/All Editions, EMBASE, Australasian Medical Index and PsychINFO. There was no date restriction applied. In addition, the reference lists of all included studies were scrutinised for other potentially relevant studies. Systematic reviews of randomised controlled trials (RCTs) and RCTs that compared the effectiveness of nursing interventions and considerations used in the administration of medications via enteral tubes. Other research methods, such as non-randomised controlled trials, longitudinal studies, cohort and case control studies, were also included. Exclusion criteria included studies investigating drug-nutrient interactions or the bioavailability of specific medications. Initial consideration of potential relevance to the review was carried out by the primary author (NP). Two reviewers independently assessed study eligibility for inclusion. A meta-analysis could not be undertaken, as there were no comparable RCTs identified. All data were presented in a narrative summary. There is very limited evidence regarding the effectiveness of nursing interventions in minimising the complications associated with enteral tube medication administration in adults. The review highlights a lack of high quality research on many important nursing issues relating to enteral medication administration. There is huge scope for further research. Some of the evidence that was identified included that nurses should consider the use of liquid form medications as there may be fewer tube occlusions than with solid forms in nasoenteral tubes and silicone percutaneous endoscopic gastronomy tubes. Nurses may need to consider the sorbitol content of some liquid medications, for example, elixirs, as diarrhoea has been attributed to the sorbitol content of the elixir, not the drug itself. In addition, the use of 30 mL of water for irrigation when administering medications or flushing small-diameter nasoenteral tubes may reduce the number of tube occlusions.

Nursing administration of medication via enteral tubes in adults: a systematic review.

PubMed

Phillips, Nicole M; Nay, Rhonda

2007-09-01

Background  Enteral tubes are frequently inserted as part of medical treatment in a wide range of patient situations. Patients with an enteral tube are cared for by nurses in a variety of settings, including general and specialised acute care areas, aged care facilities and at home. Regardless of the setting, nurses have the primary responsibility for administering medication through enteral tubes. Medication administration via an enteral tube is a reasonably common nursing intervention that entails a number of skills, including preparing the medication, verifying the tube position, flushing the tube and assessing for potential complications. If medications are not given effectively through an enteral tube, harmful consequences may result leading to increased morbidity, for example, tube occlusion, diarrhoea and aspiration pneumonia. There are resultant costs for the health-care system related to possible increased length of stay and increased use of equipment. Presently what is considered to be best practice to give medications through enteral tubes is unknown. Objectives  The objective of this systematic review was to determine the best available evidence on which nursing interventions are effective in minimising the complications associated with the administration of medications via enteral tubes in adults. Nursing interventions and considerations related to medication administration included form of medication, verifying tube placement before administration, methods used to give medication, methods used to flush tubes, maintenance of tube patency and specific practices to prevent possible complications related to the administration of enteral medications. Search strategy  The following databases were searched for literature reported in English only: CINAHL, MEDLINE, The Cochrane Library, Current Contents/All Editions, EMBASE, Australasian Medical Index and PsychINFO. There was no date restriction applied. In addition, the reference lists of all included studies were scrutinised for other potentially relevant studies. Selection criteria  Systematic reviews of randomised controlled trials (RCTs) and RCTs that compared the effectiveness of nursing interventions and considerations used in the administration of medications via enteral tubes. Other research methods, such as non-randomised controlled trials, longitudinal studies, cohort and case control studies, were also included. Exclusion criteria included studies investigating drug-nutrient interactions or the bioavailability of specific medications. Data collection and analysis  Initial consideration of potential relevance to the review was carried out by the primary author (NP). Two reviewers independently assessed study eligibility for inclusion. A meta-analysis could not be undertaken, as there were no comparable RCTs identified. All data were presented in a narrative summary. Results  There is very limited evidence regarding the effectiveness of nursing interventions in minimising the complications associated with enteral tube medication administration in adults. The review highlights a lack of high quality research on many important nursing issues relating to enteral medication administration. There is huge scope for further research. Some of the evidence that was identified included that nurses should consider the use of liquid form medications as there may be fewer tube occlusions than with solid forms in nasoenteral tubes and silicone percutaneous endoscopic gastronomy tubes. Nurses may need to consider the sorbitol content of some liquid medications, for example, elixirs, as diarrhoea has been attributed to the sorbitol content of the elixir, not the drug itself. In addition, the use of 30 mL of water for irrigation when administering medications or flushing small-diameter nasoenteral tubes may reduce the number of tube occlusions.

Graphene-coated coupling coil for AC resistance reduction

DOEpatents

Miller, John M

2014-03-04

At least one graphene layer is formed to laterally surround a tube so that the basal plane of each graphene layer is tangential to the local surface of the tube on which the graphene layer is formed. An electrically conductive path is provided around the tube for providing high conductivity electrical path provided by the basal plane of each graphene layer. The high conductivity path can be employed for high frequency applications such as coupling coils for wireless power transmission to overcome skin depth effects and proximity effects prevalent in high frequency alternating current paths.

High-voltage supply for neutron tubes in well-logging applications

DOEpatents

Humphreys, D.R.

1982-09-15

A high voltage supply is provided for a neutron tube used in well logging. The biased pulse supply of the invention combines DC and full pulse techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.

Freestanding diamond films: plates, tubes, and curved diaphragms

NASA Astrophysics Data System (ADS)

Obata, Tatsuo; Morimoto, Shingo

1990-01-01

Free-standing diamond films are prepared by CVD technique to examine their properties directly. The products have a variety of shapes such as plates, tubes and curved diaphragms. Coefficients of thermal expansion (GTE) of the tube are similar to the values of a bulk diamond in the range from 40°C to 500°C. It is found that polished diamond film has uniform infrared transmission ranging from 500cm-1 to 4000cm-1. A speaker diaphragm will be a good application for free-standing diamond film.

Tamper-indicating seal

DOEpatents

Fiarman, S.; Degen, M.F.; Peters, H.F.

1982-08-13

There is disclosed a tamper-indicating seal that permits in the field inspection and detection of tampering. Said seal comprises a shrinkable tube having a visible pattern of markings which is shrunk over th item to be sealed, and a second transparent tube, having a second visible marking pattern, which is shrunk over the item and the first tube. The relationship between the first and second set of markings produces a pattern so that the seal may not be removed without detection. The seal is particularly applicable to UF/sub 6/ cylinder valves.

Removal of a glowing spot from an image tube using laser radiation.

NASA Technical Reports Server (NTRS)

Gurski, T. R.

1972-01-01

A troublesome problem with the Kron electronograph has been the presence of a white glowing spot on the glass wall of the tube adjacent to the focus electrode. The procedure followed to eliminate the spot was to operate in the dark and apply voltage only to the focused electrode. Ruby laser radiation was unfocused, and its position was shifted on the electrode between laser shots until an effect was observed. This technique for removing the glowing spot should be applicable to other electronic image tubes.

High voltage supply for neutron tubes in well logging applications

DOEpatents

Humphreys, D. Russell

1989-01-01

A high voltage supply is provided for a neutron tube used in well logging. The "biased pulse" supply of the invention combines DC and "full pulse" techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.

Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results

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

O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert

2002-08-01

A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numericalmore » modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.« less

The value of negative Chlamydia trachomatis antibody in prediction of normal tubes in infertile women.

PubMed

Raoofi, Z; Barchinegad, M; Haghighi, L

2013-01-01

To evaluate the value of Chlamydia trachomatis antibody testing in prediction of at least one normal tube in infertile women. Eighty infertile women without any history of abdominal or pelvic surgery, pelvic inflammatory disease, and endometriosis were recruited in this cross-sectional study from 2009 to 2010. The patients underwent hysterosalpingography, laparoscopy, and anti Chlamydia trachomatis IgG antibody (CAT) testing. We compared laparoscopy findings and CAT regarding sensitivity, specificity, accuracy, and predicting value of tubal conditions. The CAT was positive in 50 patients (62.5%) and laparoscopy was positive in 32 patients (40%). The CAT was significantly higher in women with tubal disease (1.88 +/- 0.34) versus in women with normal tubes (1.21 +/- 0.28) (p = 0.003). Five out of 30 sero-negative women had unilateral tubal abnormality and none of them had bilateral tubal obstruction or severe pelvic adhesion. The sensitivity, specificity, positive and negative predictive value, and accuracy of the CAT in prediction of one normal tube were 100%, 42.25%, 18%, 100%, and 48.75%, respectively. The negative predictive value of CAT to predict at least one normal tube in infertile women without history of abdominal or pelvic surgery, pelvic inflammatory disease, and endometriosis was 100%.

Particle shedding from peristaltic pump tubing in biopharmaceutical drug product manufacturing.

PubMed

Saller, Verena; Matilainen, Julia; Grauschopf, Ulla; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

2015-04-01

In a typical manufacturing setup for biopharmaceutical drug products, the fill and dosing pump is placed after the final sterile filtration unit in order to ensure adequate dispensing accuracy and avoid backpressure peaks. Given the sensitivity of protein molecules, peristaltic pumps are often preferred over piston pumps. However, particles may be shed from the silicone tubing employed. In this study, particle shedding and a potential turbidity increase during peristaltic pumping of water and buffer were investigated using three types of commercially available silicone tubing. In the recirculates, mainly particles of around 200 nm next to a very small fraction of particles in the lower micrometer range were found. Using 3D laser scanning microscopy, surface roughness of the inner tubing surface was found to be a determining factor for particle shedding from silicone tubing. As the propensity toward particle shedding varied between tubing types and also cannot be concluded from manufacturer's specifications, individual testing with the presented methods is recommended during tubing qualification. Choosing low abrasive tubing can help to further minimize the very low particle counts to be expected in pharmaceutical drug products. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

REACTOR UNLOADING MEANS

DOEpatents

Cooper, C.M.

1957-08-20

A means for remotely unloading irradiated fuel slugs from a neutronic reactor core and conveying them to a remote storage tank is reported. The means shown is specifically adapted for use with a reactor core wherein the fuel slugs are slidably held in end to end abutting relationship in the horizontal coolant flow tubes, the slugs being spaced from tae internal walls of the tubes to permit continuous circulation of coolant water therethrough. A remotely operated plunger at the charging ends of the tubes is used to push the slugs through the tubes and out the discharge ends into a special slug valve which transfers the slug to a conveying tube leading into a storage tank. Water under pressure is forced through the conveying tube to circulate around the slug to cool it and also to force the slug through the conveving tube into the storage tank. The slug valve and conveying tube are shielded to prevent amy harmful effects caused by the radioactive slug in its travel from the reactor to the storage tank. With the disclosed apparatus, all the slugs in the reactor core can be conveyed to the storage tank shortly after shutdown by remotely located operating personnel.

A rapid single-tube protocol for HAV detection by nested real-time PCR.

PubMed

Hu, Yuan; Arsov, Ivica

2014-09-01

Infections by food-borne viruses such as hepatitis A virus (HAV) and norovirus are significant public health concerns worldwide. Since food-borne viruses are rarely confirmed through direct isolation from contaminated samples, highly sensitive molecular techniques remain the methods of choice for the detection of viral genetic material. Our group has previously developed a specific nested real-time PCR (NRT-PCR) assay for HAV detection that improved overall sensitivity. Furthermore in this study, we have developed a single-tube NRT-PCR approach for HAV detection in food samples that reduces the likelihood of cross contamination between tubes during sample manipulation. HAV RNA was isolated from HAV-spiked food samples and HAV-infected cell cultures. All reactions following HAV RNA isolation, including conventional reverse transcriptase PCR, nested-PCR, and RT-PCR were performed in a single tube. Our results demonstrated that all the samples tested positive by RT-PCR and nested-PCR were also positive by a single-tube NRT-PCR. The detection limits observed for HAV-infected cell cultures and HAV-spiked green onions were 0.1 and 1 PFU, respectively. This novel method retained the specificity and robustness of the original NRT-PCR method, while greatly reducing sample manipulation, turnaround time, and the risk of carry-over contamination. Single-tube NRT-PCR thus represents a promising new tool that can potentially facilitate the detection of HAV in foods thereby improving food safety and public health.

Actin-membrane interactions mediated by NETWORKED2 in Arabidopsis pollen tubes through associations with Pollen Receptor-Like Kinase 4 and 5.

PubMed

Duckney, Patrick; Deeks, Michael J; Dixon, Martin R; Kroon, Johan; Hawkins, Timothy J; Hussey, Patrick J

2017-12-01

During fertilization, Pollen Receptor-Like Kinases (PRKs) control pollen tube growth through the pistil in response to extracellular signals, and regulate the actin cytoskeleton at the tube apex to drive tip growth. We investigated a novel link between membrane-integral PRKs and the actin cytoskeleton, mediated through interactions between PRKs and NET2A; a pollen-specific member of the NETWORKED superfamily of actin-binding proteins. We characterize NET2A as a novel actin-associated protein that localizes to punctae at the plasma membrane of the pollen tube shank, which are stably associated with cortical longitudinal actin cables. NET2A was demonstrated to interact specifically with PRK4 and PRK5 in Nicotiana benthamiana transient expression assays, and associated at discreet foci at the shank membrane of Arabidopsis pollen tubes. Our data indicate that NET2A is recruited to the plasma membrane by PRK4 and PRK5, and that PRK kinase activity is important in facilitating its interaction with NET2A. We conclude that NET2A-PRK interactions mediate discreet sites of stable interactions between the cortical longitudinal actin cables and plasma membrane in the shank region of growing pollen tubes, which we have termed Actin-Membrane Contact Sites (AMCSs). Interactions between PRKs and NET2A implicate a role for NET2A in signal transduction to the actin cytoskeleton during fertilization. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Alloy 690 qualification: Corrosion under prototypic heat flux and temperature conditions. Final report

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

Baum, A.J.

1995-05-01

The objective of this program was to perform qualification tests of industrial heats of thermally treated alloy 690 steam generator tubing under heat transfer conditions. Primary emphasis was focused on testing of alternate tube to tubesheet expansion processes. In addition, a background report was written to document the evolution of the alloy 690 process specification and the supporting qualification testing. While the testing was able to produce some localized corrosion of alloy 690 in the tube to tubesheet joint transition regions under highly alkaline conditions, the corrosion rates were between two and three orders of magnitude lower than the comparablemore » rates in mill annealed alloy 600 tubing. The corrosion morphology was a combination of intergranular and general corrosion, rather than the stress corrosion cracking typically found in mill annealed alloy 600 tubing.« less

Dynamics of magnetic flux tubes in an advective flow around a black hole

NASA Astrophysics Data System (ADS)

Deb, Arnab; Giri, Kinsuk; Chakrabarti, Sandip K.

2017-12-01

Entangled magnetic fields entering into an accretion flow would very soon be stretched into a dominant toroidal component due to strong differentially rotating motion inside the accretion disc. This is particularly true for weakly viscous, low angular momentum transonic or advective discs. We study the trajectories of toroidal flux tubes inside a geometrically thick flow that undergoes a centrifugal force supported shock. We also study effects of these flux tubes on the dynamics of the inflow and the outflow. We use a finite difference method (total variation diminishing) for this purpose and specifically focused on whether these flux tubes significantly affect the properties of the outflows such as its collimation and the rate. It is seen that depending upon the cross-sectional radius of the flux tubes that control the drag force, these field lines may move towards the central object or oscillate vertically before eventually escaping out of the funnel wall (pressure zero surfaces) along the vertical direction. A comparison of results obtained with and without flux tubes show these flux tubes could play a pivotal role in collimation and acceleration of jets and outflows.

Wire-in-Tube IrOx Architectures: Alternative Label-Free Immunosensor for Amperometric Immunoassay toward α-Fetoprotein.

PubMed

Li, Qingling; Liu, Dali; Xu, Lin; Xing, Ruiqing; Liu, Wei; Sheng, Kuang; Song, Hongwei

2015-10-14

A sensitive, label-free immunosensor based on iridium oxide (IrOx, 0≤x≤2) nanofibers, which were synthesized through a simple one-spinneret electrospinning method, was first developed for immunoassay of the cancer biomarker α-fetoprotein (AFP). The specific wire-in-tube nanostructure could be obtained and the composition of IrOx nanofibers also could be controlled through changing the annealing temperature. The unique structure and properties of IrOx nanofibers obtained at 500 °C not only led to increased electrode surface area and accelerated electron transfer kinetics but also could provide a highly stable matrix for the convenient conjugation of biomolecules together with chitosan (CS). The good electrochemical properties of the IrOx-nanofiber-modified immunosensor allowed one to detect AFP over a wide concentration range from 0.05 to 150 ng/mL, with a detection limit of 20 pg/mL. The proposed immunosensor also has been used to determine AFP in human serum with satisfactory results. The present protocol was shown to be quite promising for clinical screening of cancer biomarkers and point-of-care diagnostics applications.

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

RHODES, WILLIAM

As part of the HEU Blend Down project, aluminum tape is required to seal aluminum tubes that will hold contaminated Mark 22 fuel tubes for dissolution. From a large field of candidate tapes, Avery Dennison's Fasson 0802 tape (synthetic rubber adhesive system) was found to be acceptable for this application. This tape will disentangle in the normal H-Canyon dissolver solution and have no detrimental effect on the H-Canyon process. Upon placement of Fasson 0802 tape into the dissolver solution, nitric acid will attack and disentangle the block copolymer network and destroy the adhesive nature of the material, resulting in insolublemore » particles that can be removed via centrifuge operations (cake weight increase of no more than 1 percent). The addition of the tape will not generate off-gas products and the resultant solution characteristics (surface tension, viscosity, density, and disengagement time) will be unaffected. Further, the potential effect on the down-stream evaporation system is negligible. Since the tape will not be placed in a high radiation environment, radiation stability is not an issue. Through detailed discussions with Avery Dennison chemists and based on analytical tests, a fairly detailed understanding of the constituents comprising the proprietary adhesive system has been assembled. Most importantly, chlorine was not detected in the aluminum tape (neutron activation analysis detection limit is 16 ppm). Finally, application of this tape will not impact LEU specifications.« less

The pollen-specific R-SNARE/longin PiVAMP726 mediates fusion of endo- and exocytic compartments in pollen tube tip growth

PubMed Central

Guo, Feng; McCubbin, Andrew G.

2012-01-01

The growing pollen tube apex is dedicated to balancing exo- and endocytic processes to form a rapidly extending tube. As perturbation of either tends to cause a morphological phenotype, this system provides tractable model for studying these processes. Vesicle-associated membrane protein 7s (VAMP7s) are members of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family that mediate cognate membrane fusion but their role in pollen tube growth has not been investigated. This manuscript identifies PiVAMP726 of Petunia inflata as a pollen-specific VAMP7 that localizes to the inverted cone of transport vesicles at the pollen tube tip. The endocytic marker FM4-64 was found to colocalize with yellow fluorescent protein (YFP)-PiVAMP726, which is consistent with PiVAMP726 containing an amino-acid motif implicated in endosomal localization, At high overexpression levels, YFP- PiVAMP726 inhibited growth and caused the formation of novel membrane compartments within the pollen tube tip. Functional dissection of PiVAMP726 implicated the N-terminal longin domain in negative regulation of the SNARE activity, but not localization of PiVAMP726. Expression of the constitutively active C-terminal SNARE domain alone, in pollen tubes, generated similar phenotypes to the full-length protein, but the truncated domain was more potent than the wild-type protein at both inhibiting growth and forming the novel membrane compartments. Both endo- and exocytic markers localized to these compartments in addition to YFP-PiVAMP726, leading to the speculation that PiVAMP726 might be involved in the recycling of endocytic vesicles in tip growth. PMID:22345643

Comparison between transthoracic lung ultrasound and a clinical method in confirming the position of double-lumen tube in thoracic anaesthesia. A pilot study.

PubMed

Álvarez-Díaz, N; Amador-García, I; Fuentes-Hernández, M; Dorta-Guerra, R

2015-01-01

To compare the ability of lung ultrasound and a clinical method in the confirmation of a selective bronchial intubation by left double-lumen tube in elective thoracic surgery. A prospective and blind, observational study was conducted in the setting of a university hospital operating room assigned for thoracic surgery. A single group of 105 consecutive patients from a total of 130, were included. After blind intubation, the position of the tube was confirmed by clinical and ultrasound assessment. Finally, the fiberoptic bronchoscopy confirmation as a reference standard was used to confirm the position of the tube. Under manual ventilation, by sequentially clamping the tracheal and bronchial limbs of the tube, clinical confirmation was made by auscultation, capnography, visualizing the chest wall expansion, and perceiving the lung compliance in the reservoir bag. Ultrasound confirmation was obtained by visualizing lung sliding, diaphragmatic movements, and the appearance of lung pulse sign. The sensitivity of the clinical method was 84.5%, with a specificity of 41.1%. The positive and negative likelihood ratio was 1.44 and 0.38, respectively. The sensitivity of the ultrasound method was 98.6%, specificity was 52.9%, with a positive likelihood ratio of 2.10 and a negative likelihood ratio of 0.03. Comparisons between the diagnostic performance of the 2 methods were calculated with McNemar's test. There was a significant difference in sensitivity between the ultrasound method and the clinical method (P=.002). Nevertheless, there was no statistically significant difference in specificity between both methods (P=.34). A p value<.01 was considered statistically significant. Lung ultrasound was superior to the clinical method in confirming the adequate position of the left double-lumen tube. On the other hand, in confirming the misplacement of the tube, differences between both methods could not be ensured. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Novel Low-Cost, Low-Power Miniature Thermionic Cathode Developed for Microwave/Millimeter Wave Tube and Cathode Ray Tube Applications

NASA Technical Reports Server (NTRS)

Wintucky, Edwin G.

1999-01-01

A low cost, small size and mass, low heater power, durable high-performance barium dispenser thermionic cathode has been developed that offers significant advancements in the design, manufacture, and performance of the electron sources used in vacuum electronic devices--such as microwave (and millimeter wave) traveling-wave tubes (TWT's)--and in display devices such as high-brightness, high-resolution cathode ray tubes (CRT's). The lower cathode heater power and the reduced size and mass of the new cathode are expected to be especially beneficial in TWT's for deep space communications, where future missions are requiring smaller spacecraft, higher data transfer rates (higher frequencies and radiofrequency output power), and greater electrical efficiency. Also expected to benefit are TWT's for commercial and government communication satellites, for both low and geosynchronous Earth orbit, with additional benefits offered by lower cost and potentially higher cathode current loading. A particularly important TWT application is in the microwave power module (MPM), which is a hybrid microwave (or millimeter wave) amplifier consisting of a low-noise solid state driver, a vacuum power booster (small TWT), and an electronic power conditioner integrated into a single compact package. The attributes of compactness and potentially high electrical efficiency make the MPM very attractive for many commercial and government (civilian and defense) applications in communication and radar systems. The MPM is already finding application in defense electronic systems and is under development by NASA for deep space communications. However, for the MPM to become competitive and commercially successful, a major reduction in cost must be achieved.

Multiplex real-time PCR assays for the identification of the potato cyst and tobacco cyst nematodes

USDA-ARS?s Scientific Manuscript database

TaqMan primer-probe sets were developed for the detection and identification of potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis using two-tube, multiplex real-time PCR. One tube contained a primer-probe set specific for G. pallida (pale cyst nematode) multiplexed with another prim...

iMAST FY2007 Annual Report

DTIC Science & Technology

2007-01-01

laser cladding techniques. Customer: COMSUBPAC NAVSEASYSCOM Pearl Harbor Naval Shipyard...motion device to laser clad and re-dimension the affected tube to original specifications. Benefits: ° Reduce life cycle costs of tube...coatings via cold gas dynamic spraying and EB–PVD ° Spray-formed HT aluminum alloys ° Localized laser HT and cladding for wear

21 CFR 524.1195 - Ivermectin otic suspension.

Code of Federal Regulations, 2011 CFR

2011-04-01

....1195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Ivermectin otic suspension. (a) Specifications. Each tube contains 0.5 milliliter (mL) of a 0.01 percent...—(1) Amount. Administer the contents of one 0.5-mL tube topically into each external ear canal. (2...

21 CFR 524.1195 - Ivermectin otic suspension.

Code of Federal Regulations, 2010 CFR

2010-04-01

....1195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Ivermectin otic suspension. (a) Specifications. Each tube contains 0.5 milliliter (mL) of a 0.01 percent...—(1) Amount. Administer the contents of one 0.5-mL tube topically into each external ear canal. (2...

Emerging roles for microtubules in angiosperm pollen tube growth highlight new research cues

PubMed Central

Onelli, Elisabetta; Idilli, Aurora I.; Moscatelli, Alessandra

2015-01-01

In plants, actin filaments have an important role in organelle movement and cytoplasmic streaming. Otherwise microtubules (MTs) have a role in restricting organelles to specific areas of the cell and in maintaining organelle morphology. In somatic plant cells, MTs also participate in cell division and morphogenesis, allowing cells to take their definitive shape in order to perform specific functions. In the latter case, MTs influence assembly of the cell wall, controlling the delivery of enzymes involved in cellulose synthesis and of wall modulation material to the proper sites. In angiosperm pollen tubes, organelle movement is generally attributed to the acto-myosin system, the main role of which is in distributing organelles in the cytoplasm and in carrying secretory vesicles to the apex for polarized growth. Recent data on membrane trafficking suggests a role of MTs in fine delivery and repositioning of vesicles to sustain pollen tube growth. This review examines the role of MTs in secretion and endocytosis, highlighting new research cues regarding cell wall construction and pollen tube-pistil crosstalk, that help unravel the role of MTs in polarized growth. PMID:25713579

78 FR 60321 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses and Combined Licenses...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-01

... sample selection. A steam generator tube rupture (SGTR) event is one of the design basis accidents that... in the design basis accident analysis. The proposed change will not cause the consequences of a SGTR... changes to the plant design basis or postulated accidents resulting from potential tube degradation. The...

Kinematic Measurements from YouTube Videos

ERIC Educational Resources Information Center

Ruiz, Michael J.

2009-01-01

Video analysis of motion has been in use now for some time. However, some teachers may not have video equipment or may be looking for innovative ways to engage students with interesting applications at no cost. The recent advent of YouTube offers opportunities for students to measure kinematic properties of real-life events using their computers.…

A VACUUM OPERATED INSTRUMENT FOR HANDLING RADIUM TUBES

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

Englander, O.

1964-03-01

Application of known principles resulted in the design of an apparatus for reducing exposure of x-ray technicians during the loading and unloading of radium tubes. The device offers the advantage of an increased distance between radium and fingers as compared with the conventionally used 25 mm forceps. A diagram of the instrument is included. (H.M.G.)

Computer-Aided Thermohydraulic Design of TEMA Type E Shell and Tube Heat Exchangers for Use in Low Pressure, Liquid-to-Liquid, Single Phase Applications.

DTIC Science & Technology

1985-04-01

and Standards .. ... ....... ....... 9 A. General . ... .. .. ... ..... .. .. ... 9 B. ASME Boiler and Pressure Vessel Code .. .. ......9 C. Foreign...several different sources. B. American Society of Mechanial Engineers (ASME) Boiler and Pressure Vessel Code A shell and tube heat exchanger is indeed a

Flow tube used to cool solar-pumped laser

NASA Technical Reports Server (NTRS)

1968-01-01

A flow tube has been designed and constructed to provide two major functions in the application of a laser beam for transmission of both sound and video. It maintains the YAG laser at the proper operating temperature of 300 degrees K under solar pumping conditions, and it serves as a pump cavity for the laser crystal.

Empowering Learners as the Owners of Feedback while YouTube-ing

ERIC Educational Resources Information Center

Ng, Huey Zher; Hussain, Raja Maznah Raja

2009-01-01

Purpose: The application of a new technology (YouTube) can help lecturers in solving some of the issues related to workload and shifts support to students by giving them more responsibilities in their assessment. The purpose of this paper is to re-characterize the role of the students in the assessment process. Design/methodology/approach:…

78 FR 26343 - Exelon Generation Company, LLC; Notice of Application Accepted for Filing, Soliciting Motions To...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-06

... prior registration, using the eComment system at http://www.ferc.gov/docs-filing/ecomment.asp . You must... plant is integral with the dam and is composed of 13 turbine-generator units, draft tubes, and.... Water flowing through the turbines is discharged via the draft tubes into the tailrace immediately...

Contracting/expanding self-sealing cryogenic tube seals

NASA Technical Reports Server (NTRS)

Jia, Lin X. (Inventor)

1997-01-01

Contracting/expanding self-sealing cryogenic tube seals are disclosed which use the different properties of thermal contraction and expansion of selected dissimilar materials in accord with certain design criteria to yield self-tightening seals via sloped-surface sealing. The seals of the subject invention are reusable, simple to assemble, and adaptable to a wide variety of cryogenic applications.

Magnetically Operated Holding Plate And Ball-Lock Pin

NASA Technical Reports Server (NTRS)

Monford, Leo G., Jr.

1992-01-01

Magnetically operated holding plate and ball-locking-pin mechanism part of object attached to, or detached from second object. Mechanism includes tubular housing inserted in hole in second object. Plunger moves inside tube forcing balls to protrude from sides. Balls prevent tube from sliding out of second object. Simpler, less expensive than motorized latches; suitable for robotics applications.

Contracting/expanding self-sealing cryogenic tube seals

NASA Technical Reports Server (NTRS)

Jia, Lin X. (Inventor)

1997-01-01

Contracting/expanding self-sealing cryogenic tube seals are disclosed which use the different properties of thermal contraction and expansion of selected dissimilar materials in accord with certain design criteria to yield self-tightening seals via sloped-surface sealing. The seals of the subject invention are reusable, simple to assemble, adaptable to a wide variety of cryogenic applications.

Application of passive sorbent tube and canister samplers for volatile organic compounds at refinery fenceline locations in Whiting, Indiana

EPA Science Inventory

Select volatile organic compounds (VOCs) in ambient air were measured at four fenceline sites at a petroleum refinery in Whiting, Indiana, USA using modified EPA Method 325 A/B with passive tubes and EPA Compendium Method TO-15 with canister samplers. One-week, time-integrated s...

Defensin-Like ZmES4 Mediates Pollen Tube Burst in Maize via Opening of the Potassium Channel KZM1

PubMed Central

Márton, Mihaela L.; Debener, Thomas; Geiger, Dietmar; Becker, Dirk; Dresselhaus, Thomas

2010-01-01

In contrast to animals and lower plant species, sperm cells of flowering plants are non-motile and are transported to the female gametes via the pollen tube, i.e. the male gametophyte. Upon arrival at the female gametophyte two sperm cells are discharged into the receptive synergid cell to execute double fertilization. The first players involved in inter-gametophyte signaling to attract pollen tubes and to arrest their growth have been recently identified. In contrast the physiological mechanisms leading to pollen tube burst and thus sperm discharge remained elusive. Here, we describe the role of polymorphic defensin-like cysteine-rich proteins ZmES1-4 (Zea mays embryo sac) from maize, leading to pollen tube growth arrest, burst, and explosive sperm release. ZmES1-4 genes are exclusively expressed in the cells of the female gametophyte. ZmES4-GFP fusion proteins accumulate in vesicles at the secretory zone of mature synergid cells and are released during the fertilization process. Using RNAi knock-down and synthetic ZmES4 proteins, we found that ZmES4 induces pollen tube burst in a species-preferential manner. Pollen tube plasma membrane depolarization, which occurs immediately after ZmES4 application, as well as channel blocker experiments point to a role of K+-influx in the pollen tube rupture mechanism. Finally, we discovered the intrinsic rectifying K+ channel KZM1 as a direct target of ZmES4. Following ZmES4 application, KZM1 opens at physiological membrane potentials and closes after wash-out. In conclusion, we suggest that vesicles containing ZmES4 are released from the synergid cells upon male-female gametophyte signaling. Subsequent interaction between ZmES4 and KZM1 results in channel opening and K+ influx. We further suggest that K+ influx leads to water uptake and culminates in osmotic tube burst. The species-preferential activity of polymorphic ZmES4 indicates that the mechanism described represents a pre-zygotic hybridization barrier and may be a component of reproductive isolation in plants. PMID:20532241

Numerical Study of a 10 K Two Stage Pulse Tube Cryocooler with Precooling Inside the Pulse Tube

NASA Astrophysics Data System (ADS)

Xiaomin, Pang; Xiaotao, Wang; Wei, Dai; Jianyin, Hu; Ercang, Luo

2017-02-01

High efficiency cryocoolers working below 10 K have many applications such as cryo-pump, superconductor cooling and cryogenic electronics. This paper presents a thermally coupled two-stage pulse tube cryocooler system and its numeric analysis. The simulation results indicate that temperature distribution in the pulse tube has a significant impact on the system performance. So a precooling heat exchanger is put inside the second stage pulse tube for a deep investigation on its influence on the system performance. The influences of operating parameters such as precooling temperature, location of the precooling heat exchanger are discussed. Comparison of energy losses apparently show the advantages of the configuration which leads to an improvement on the efficiency. Finally, the cryocooler is predicted to be able to reach a relative Carnot efficiency of 10.7% at 10 K temperature.

Experimental Characterisation of a Pulse Tube Cryocooler for Ground Applications

NASA Astrophysics Data System (ADS)

Charles, I.; Duband, L.; Martin, J.-Y.; Mullié, J. C.; Bruins, P. C.

2004-06-01

Developments on high frequency high heat lift pulse tubes are carried out at CEA/SBT. Based on a previous study on an in line configuration, two new pulse tube cold fingers have been manufactured: a coaxial configuration and a U-shape configuration. Measurements performed with the coaxial configuration have demonstrated cooling power in excess of 6 W at 80 K with 140 W of mechanical input power. The results obtained with these two configurations are presented. The impact of the rejection temperature has also been studied and is discussed. In parallel, a new compressor with pistons supported by flexure bearings has been designed and manufactured. This compressor has been coupled with the pulse tube. Tests performed with the new developed flexure-bearing compressors and a conventional compressor are presented and compared. The pulse tube cold finger associated with the new compressor leads to a reliable and low vibration cooler.

a High Frequency Thermoacoustically-Driven Pulse Tube Cryocooler with Coaxial Resonator

NASA Astrophysics Data System (ADS)

Yu, G. Y.; Wang, X. T.; Dai, W.; Luo, E. C.

2010-04-01

High frequency thermoacoustically-driven pulse tube cryocoolers are quite promising due to their compact size and high reliability, which can find applications in space use. With continuous effort, a lowest cold head temperature of 68.3 K has been obtained on a 300 Hz pulse tube cryocooler driven by a standing-wave thermoacoustic heat engine with 4.0 MPa helium gas and 750 W heat input. To further reduce the size of the system, a coaxial resonator was designed and the two sub-systems, i.e., the pulse tube cryocooler and the standing-wave thermoacoustic heat engine were properly coupled through an acoustic amplifier tube, which leads to a system axial length of only about 0.7 m. The performance of the system with the coaxial resonator was tested, and shows moderate degradation compared to that with the in-line resonator, which might be attributed to the large flow loss of the 180 degree corner.

The deformation of flux tubes in the solar wind with applications to the structure of magnetic clouds and CMEs

NASA Technical Reports Server (NTRS)

Cargill, Peter J.; Chen, James; Spicer, D. S.; Zalesak, S. T.

1994-01-01

Two dimensional magnetohydrodynamic simulations of the distortion of a magnetic flux tube, accelerated through ambient solar wind plasma, are presented. Vortices form on the trailing edge of the flux tube, and couple strongly to its interior. If the flux tube azimuthal field is weak, it deforms into an elongated banana-like shape after a few Alfven transit times. A significant azimuthal field component inhibits this distortion. In the case of magnetic clouds in the solar wind, it is suggested that the shape observed at 1 AU was determined by distortion of the cloud in the inner heliosphere. Distortion of the cloud beyond 1 AU takes many days. It is estimated that effective drag coefficients slightly greater than unity are appropriate for modeling flux tube propagation. Synthetic magnetic field profiles as would be seen by a spacecraft traversing the cloud are presented.

Design and test of the Stirling-type pulse tube cryocooler

NASA Astrophysics Data System (ADS)

Hong, Yong-Ju; Ko, Junseok; Kim, Hyo-Bong; Yeom, Han-Kil; In, Sehwan; Park, Seong-Je

2017-12-01

Stirling type pulse tube cryocoolers are very attractive for cooling of diverse application because it has it has several inherent advantages such as no moving part in the cold end, low manufacturing cost and long operation life. To develop the Stirling-type pulse tube cryocooler, we need to design a linear compressor to drive the pulse tube cryocooler. A moving magnet type linear motor of dual piston configuration is designed and fabricated, and this compressor could be operated with the electric power of 100 W and the frequency up to 60 Hz. A single stage coaxial type pulse tube cold finger aiming at over 1.5 W at 80K is built and tested with the linear compressor. Experimental investigations have been conducted to evaluate their performance characteristics with respect to several parameters such as the phase shifter, the charging pressure and the operating frequency of the linear compressor.

Contractility of glycerinated Amoeba proteus and Chaos-chaos.

PubMed

Rinaldi, R; Opas, M; Hrebenda, B

1975-05-01

Immediate contact with large volumes of cold 50% (v/v) buffered glycerol preserved typical ameboid shape of Chaos chaos and Amoeba proteus with no visible distortions. These technics allowed determination of the contraction sites in these glycerinated models upon applications of ATP-Ca-Mg-solutions. The ectoplasmic tube was the main site of contraction. Preliminary EM investigations revealed thick and thin filaments, associated with the ectoplasmic tube near the plasma-lemma, which appeared to be the basis for the contractility of the ectoplasmic tube. There was no predominant contraction of the pseudopodial tips or the endoplasm in these models. The changes of volume were as much as 50%, and in some cases were not accompanied by any change in the length of the ameba; however, lengthwise contractions of the ectoplasmic tube in some amebae occurred to as much as 25%. The data substantiate a basic requirement of the ectoplasmic tube contraction theory of ameboid locomotion.

Microtiter format for simultaneous multianalyte detection and development of a PCR-chemiluminescent enzyme immunoassay for typing human papillomavirus DNAs.

PubMed

Roda, Aldo; Mirasoli, Mara; Venturoli, Simona; Cricca, Monica; Bonvicini, Francesca; Baraldini, Mario; Pasini, Patrizia; Zerbini, Marialuisa; Musiani, Monica

2002-10-01

To allow multianalyte binding assays, we have developed a novel polystyrene microtiter plate containing 24 main wells, each divided into 7 subwells. We explored its clinical potential by developing a PCR-chemiluminescent immunoassay (PCR-CLEIA) for simultaneous detection and typing of seven high oncogenic risk human papillomavirus (HPV) DNAs in one well. Seven different oligonucleotide probes, each specific for a high-risk HPV genotype, were separately immobilized in the subwells. Subsequently, a digoxigenin-labeled consensus PCR amplification product was added to the main well. The PCR product hybridized to the immobilized probe corresponding to its genotype and was subsequently detected by use of a peroxidase-labeled anti-digoxigenin antibody and chemiluminescence imaging with an ultrasensitive charge-coupled device camera. Results obtained for 50 cytologic samples were compared with those obtained with a conventional colorimetric PCR-ELISA. The method was specific and allowed detection of 50 genome copies of HPV 16, 18, 33, and 58, and 100 genome copies of HPV 31, 35, and 45. Intra- and interassay CVs for the method were 5.6% and 7.9%, respectively. All results obtained for clinical samples were confirmed by the conventional PCR-ELISA. PCR-CLEIA allows rapid, single-tube simultaneous detection and typing of seven high-risk HPV DNAs with small reagent volumes. The principle appears applicable to the development of other single-tube panels of tests.

Cryocoolers for aircraft superconducting generators and motors

NASA Astrophysics Data System (ADS)

Radebaugh, Ray

2012-06-01

The proposal by NASA to use high-temperature superconducting (HTS) generators and motors on future (~2035) aircraft for turboelectric propulsion imposes difficult requirements for cryocoolers. Net refrigeration powers of about 5 kW to 10 kW at 50 K to 65 K are needed for this application. A 2010 survey by Ladner of published work between 1999 and 2009 on existing Stirling and Stirling-type pulse tube cryocoolers showed efficiencies in the range of 10 to 20 % of Carnot at 50 K, much less than the 30 % of Carnot needed to make the concept feasible. A cryocooler specific mass less than about 3 kg/kW of input power is required to keep the cryocooler mass somewhat less than the mass of the superconducting machinery. Current cryocoolers have specific masses about 3 to 10 times this desired value, even for those designed for airborne or space use. We discuss loss and mass sources and make suggestions where improvements can be made. For Stirling and Stirling-type pulse tube cryocoolers, most of the mass is concentrated in the compressor. We show that higher frequency and pressure can have a major influence on reducing the compressor mass. Frequencies up to about 120 Hz and average pressures up to about 5 MPa may significantly reduce the overall cryocooler size and mass while maintaining high efficiency. Other suggestions for reducing the mass are also given.