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Sample records for 304l ss tubing

  1. Fatigue cracking of coextruded 304L/CS tubes

    SciTech Connect

    Swindeman, R.W.; Keiser, J.R.; Maziasz, P.J.; Singbeil, D.L.

    1998-03-01

    The mechanical and thermal fatigue of authentic stainless steels was examined for the maximum temperature range expected in coextruded floor tubes of recovery boilers to determine the likelihood that the cracking in the 304L stainless steel cladding could be fatigue related. The microstructures and cracking patterns of fatigue-tested specimens were compared to features observed in cracked cladding and significant differences were found which suggested that fatigue was not the most likely cause for failure. Biaxial thermal fatigue testing of coextruded tubes and panels was performed to gather more evidence of cracking patterns. Here, transient thermal stresses were imposed by rapidly heating the tubing surface with lamps. In spite of high surface temperatures, no cracks were produced in the 304L stainless steel cladding, and this observation was interpreted as evidence that cracking must be corrosion related.

  2. Optimization of Heat Treatments for Reversion of Strain-Induced Martensite in 304L SS Explosive Clad

    NASA Astrophysics Data System (ADS)

    Prasanthi, T. N.; Sudha, C.; Parida, P. K.; Dasgupta, Arup; Saroja, S.

    2016-02-01

    Explosive clad joints of 304L SS and Ti-5Ta-2Nb alloy, fabricated for an important application in the spent nuclear fuel reprocessing industry showed formation of deformation induced metastable α' martensite and fcc Ti phase in SS and TiTaNb alloy respectively. A biphasic structure consisting of metastable phases is not preferred for industrial applications due to degradation of corrosion and mechanical properties of the structural materials during service. Hence, it is essential to carry out post cladding heat treatments. The results reported in this paper provide evidence for the presence of α' phase in 304L SS in `as clad' joints and its reversion process during thermal exposure. The temperature window in the range of 400-700 °C and time was optimized based on complete transformation of the metastable phases to parent phases, and avoiding the formation of brittle Fe-Ti intermetallics at the interface. A systematic increase in the fraction of austenite phase associated with the reversion phenomena has been studied using electron back scattered diffraction and transmission electron microscopy. Orientation relationship between product fcc and parent bcc phases was found to obey the K-S relationship. The reverted γ phase was found to nucleate within the martensite laths. A temperature of 550 °C for duration of about 10 h was found to be optimum for the post cladding treatments of the explosive clad joints.

  3. Prediction and Confirmation of Phases Formed in the Diffusion Zone of Ti-5Ta-2Nb/304L SS Explosive Clads

    NASA Astrophysics Data System (ADS)

    Prasanthi, T. N.; Sudha, Cheruvathur; Parida, P. K.; Dasgupta, A.; Saroja, S.

    2015-04-01

    Explosive cladding, a solid-state welding technique was used to fabricate dissimilar joints between Ti-5Ta-2Nb alloy and 304L austenitic stainless steel. To remove the residual stresses and improve the ductility of the `as clad' joints, further heat treatments were carried out in the temperature range of 873 K to 1073 K (600 °C to 800 °C) for varying durations. Systematic change in the interface microstructure and microchemistry due to thermally activated interdiffusion of alloying elements was studied. This information together with that of the thermal stability of non-equilibrium phases in base materials was used to evaluate the probability of formation of various phases across the explosive clad interface using JMatPro®, a materials modeling software. In the clad heat treated at 1073 K (800 °C) for 20 hours, evidence was obtained for the presence of different phases (predicted to form) in the diffusion zone by transmission electron microscopy on site-specific specimens prepared by focused ion beam milling. An attempt to understand the specific influence of the type of phase, their relative mole fraction, and microchemistry on the mechanical property of the joint has also been made based on both experimental and computational study.

  4. Finite-element modelling of low-temperature autofrettage of thick-walled tubes of the austenitic stainless steel AISI 304 L: Part II. Thick-walled tube with cross-bore

    NASA Astrophysics Data System (ADS)

    Feng, H.; Donth, B.; Mughrabi, H.

    1998-01-01

    In part I, the autofrettage of a smooth thick-walled tube of the austenitic stainless steel AISI 304 L was studied by finite-element (FE) modelling. It was shown that low- temperature autofrettage is more efficient than autofrettage at room temperature, since it produces a larger beneficial compressive residual tangential (hoop) stress at the inner bore of the tube and hence permits a more significant enhancement of the fatigue resistance against pulsating internal pressure. The objective of the present study (part II) was to investigate the technically more relevant case of a thick-walled tube with a cross-bore made of the same steel. For this purpose, three-dimensional FE calculations were performed in order to characterize the influences of the autofrettage pressure and temperature on the stress and strain changes, in particular at the site of the cross-bore, also taking into account the effects of work hardening and reverse yielding. The results indicate that low-temperature autofrettage can also be applied advantageously in the case of thick-walled tubes with a cross-bore by virtue of the significantly larger residual compressive stresses, compared to room temperature autofrettage. From the quantitative FE calculations, the optimal combination of autofrettage temperature and pressure were concluded to lie in the range of 0965-0393/6/1/007/img1 to 0965-0393/6/1/007/img2, respectively. The calculated results were found to be in fair agreement with the measured values.

  5. Finite-element modelling of low-temperature autofrettage of thick-walled tubes of the austenitic stainless steel AISI 304 L: Part I. Smooth thick-walled tubes

    NASA Astrophysics Data System (ADS)

    Feng, H.; Mughrabi, H.; Donth, B.

    1998-01-01

    The stresses and strains introduced by low-temperature autofrettage of smooth thick-walled tubes made of the austenitic stainless steel AISI 304 L were modelled by the finite-element (FE) method. The objective was to show that low-temperature autofrettage is much more efficient than autofrettage at room temperature in enhancing the fatigue resistance by introducing a higher beneficial tangential (hoop) residual compressive stress at the inner part of the tube. Attention was paid to the influences of the autofrettage temperature and pressure, the work hardening and the reverse yielding on the residual stress components and on the total strain components of the tube. The FE calculations confirmed that more beneficial residual stress patterns can be attained by autofrettage at low rather than at room temperature. From the quantitative calculations, the optimal autofrettage temperature and pressure of the tube were concluded to be about 0965-0393/6/1/006/img1 and 4000 bar, respectively. The results of the calculations were shown to be in good agreement with recently measured data.

  6. Microbiological influenced corrosion resistance characteristics of a 304L-Cu stainless steel against Escherichia coli.

    PubMed

    Nan, Li; Xu, Dake; Gu, Tingyue; Song, Xiu; Yang, Ke

    2015-03-01

    Cu-bearing antibacterial stainless steels have been gaining popularity in recent years due to their strong antibacterial performances. However, only a few studies were reported for their actual performances against microbiologically influenced corrosion (MIC). In this study, electrochemical methods and surface analytical techniques were applied to study the MIC resistance characteristics of a 304L-Cu stainless steel (SS) against Escherichia coli in comparison with 304L SS as control. Corrosion tests for specimens after a 21-day exposure to a Luria-Bertani (LB) culture medium with E. coli demonstrated that the 304L-Cu SS considerably reduced the maximum MIC pit depth and the specific weight loss compared with 304L SS (8.3μm and 0.2mg/cm(2) vs. 13.4μm and 0.6mg/cm(2)). Potentiodynamic polarization tests showed that the corrosion current density of the 304L-Cu SS was as much as 4 times lower than that of the 304L SS, indicating that the 304L-Cu SS is a better choice for applications in MIC-prone environments. PMID:25579918

  7. Comparison of SCC Behavior of 304L Stainless Steels With and Without Boron Addition in Acidic Chloride Environment

    NASA Astrophysics Data System (ADS)

    Sivai Bharasi, N.; Pujar, M. G.; Nirmal, S.; Mallika, C.; Kamachi Mudali, U.; Angelo, P. C.

    2016-07-01

    The stress corrosion cracking (SCC) behavior of 304L B4 grade borated stainless steel (SS) as well as 304L SS was investigated by constant load and slow strain rate testing (SSRT) techniques. The microstructure, pitting, and SCC behavior of borated SS in the as-received, sensitized, and solution-annealed conditions were analyzed. Potentiodynamic anodic polarization and double loop electrochemical potentiokinetic reactivation (DLEPR) experiments were carried out to find out pitting corrosion resistance and degree of sensitization (DOS). The number of boride particles (composed of Cr, Fe, and B) were highest for the specimen solution annealed at 1423 K/2 h. Solution-annealing treatment at 1423 K/4 h was found to be beneficial in improving the corrosion resistance of borated 304L SS. Although the borated 304L SS exhibited a higher DOS, it showed improved pitting corrosion resistance compared to 304L SS. Constant load experiments revealed the time to failure to be the highest for the specimen solution annealed at 1423 K/4 h. SCC susceptibility index (Iscc) values obtained from SSRT tests were lower for solution-annealed borated 304L SS compared to the as-received and sensitized conditions. The improved SCC resistance of borated 304L SS was attributed not only to the solution-annealing treatment but also the higher stacking fault energy (SFE) value compared to 304L SS.

  8. Comparison of SCC Behavior of 304L Stainless Steels With and Without Boron Addition in Acidic Chloride Environment

    NASA Astrophysics Data System (ADS)

    Sivai Bharasi, N.; Pujar, M. G.; Nirmal, S.; Mallika, C.; Kamachi Mudali, U.; Angelo, P. C.

    2016-05-01

    The stress corrosion cracking (SCC) behavior of 304L B4 grade borated stainless steel (SS) as well as 304L SS was investigated by constant load and slow strain rate testing (SSRT) techniques. The microstructure, pitting, and SCC behavior of borated SS in the as-received, sensitized, and solution-annealed conditions were analyzed. Potentiodynamic anodic polarization and double loop electrochemical potentiokinetic reactivation (DLEPR) experiments were carried out to find out pitting corrosion resistance and degree of sensitization (DOS). The number of boride particles (composed of Cr, Fe, and B) were highest for the specimen solution annealed at 1423 K/2 h. Solution-annealing treatment at 1423 K/4 h was found to be beneficial in improving the corrosion resistance of borated 304L SS. Although the borated 304L SS exhibited a higher DOS, it showed improved pitting corrosion resistance compared to 304L SS. Constant load experiments revealed the time to failure to be the highest for the specimen solution annealed at 1423 K/4 h. SCC susceptibility index (Iscc) values obtained from SSRT tests were lower for solution-annealed borated 304L SS compared to the as-received and sensitized conditions. The improved SCC resistance of borated 304L SS was attributed not only to the solution-annealing treatment but also the higher stacking fault energy (SFE) value compared to 304L SS.

  9. Surface working of 304L stainless steel: Impact on microstructure, electrochemical behavior and SCC resistance

    SciTech Connect

    Acharyya, S.G.; Khandelwal, A.; Kain, V.; Kumar, A.; Samajdar, I.

    2012-10-15

    The effect of surface working operations on the microstructure, electrochemical behavior and stress corrosion cracking resistance of 304L stainless steel (SS) was investigated in this study. The material was subjected to (a) solution annealing (b) machining and (c) grinding operations. Microstructural characterization was done using stereo microscopy and electron back scattered diffraction (EBSD) technique. The electrochemical nature of the surfaces in machined, ground and solution annealed condition were studied using potentiodynamic polarization and scanning electrochemical microscopy (SECM) in borate buffer solution. The stress corrosion cracking resistance of 304L SS in different conditions was studied by exposing the samples to boiling MgCl{sub 2} environment. Results revealed that the heavy plastic deformation and residual stresses present near the surface due to machining and grinding operations make 304L SS electrochemically more active and susceptible to stress corrosion cracking. Ground sample showed highest magnitude of current density in the passive potential range followed by machined and solution annealed 304L SS. Micro-electrochemical studies established that surface working promotes localized corrosion along the surface asperities which could lead to crack initiation. - Highlights: Black-Right-Pointing-Pointer Machining/grinding produce extensive grain fragmentation near the surface of 304L SS. Black-Right-Pointing-Pointer Machining/grinding result in martensitic transformation near the surface of 304L SS. Black-Right-Pointing-Pointer Machining/grinding drastically reduce the SCC resistance of 304L SS in chloride. Black-Right-Pointing-Pointer Machining/grinding make the surface of 304L SS electrochemically much more active. Black-Right-Pointing-Pointer SECM study reveal that preferential dissolution takes place along surface asperities.

  10. Dynamic Strength of 304L stainless steel under impact

    NASA Astrophysics Data System (ADS)

    Werdiger, Meir; Bakshi, Lior; Glam, Benny; Pistinner, Shlomi

    2011-06-01

    We use the Asay self consistent technique to analyze the effects of pressure hardening and strain hardening on SS304L. Previously unloading experiment has been used to infer the strength of this material at high pressure, and recently the Johnson-Cook (JC) model has been calibrated at low strain rate. Release and reshock experiments with impact velocity range of 300-1700 m/s were preformed. We used VISAR to extract the particle velocity of the SS304L- LiF window interface. The velocity profile compared to hydrodynamic simulation using JC model. Our unloading experiments have clearly demonstrate that the material yield but does not fail. Thus infer substantial effect of pressure hardening.

  11. 304L stainless steel resistance to cesium chloride

    SciTech Connect

    Graves, C.E.

    1998-08-27

    B and W Hanford Company have two Oak Ridge National Laboratory (ORNL) Type 4 canisters filled with cesium chloride (CsCl) originally produced at WESF (Waste Encapsulation and Storage Facility). These canisters are constructed of 304L stainless steel per drawing ORNL 970-294. Instead of removing the CsCl from the Type 4 canisters and repacking into an Inner Capsule, it is intended (for ALARA, schedule and cost purposes) that the Type 4 canisters be decontaminated (scrubbed) and placed [whole] inside a Type ``W`` overpack. The overpack is constructed from 316L stainless steel. Several tests have been run by Pacific Northwest National Laboratory (PNNL) over the. years documenting the corrosion compatibility of 316L SS with CsCl (Bryan 1989 and Fullam 1972). However, no information for 304L SS compatibility is readily available. This document estimates the corrosion resistance of 304L stainless steel in a WESF CsCl environment as it compares with that of 316L stainless steel.

  12. Experiments for calibration and validation of plasticity and failure material modeling: 304L stainless steel.

    SciTech Connect

    Lee, Kenneth L.; Korellis, John S.; McFadden, Sam X.

    2006-01-01

    Experimental data for material plasticity and failure model calibration and validation were obtained from 304L stainless steel. Model calibration data were taken from smooth tension, notched tension, and compression tests. Model validation data were provided from experiments using thin-walled tube specimens subjected to path dependent combinations of internal pressure, extension, and torsion.

  13. Mitigation of Stress Corrosion Cracking Susceptibility of Machined 304L Stainless Steel Through Laser Peening

    NASA Astrophysics Data System (ADS)

    Sundar, R.; Ganesh, P.; Kumar, B. Sunil; Gupta, R. K.; Nagpure, D. C.; Kaul, R.; Ranganathan, K.; Bindra, K. S.; Kain, V.; Oak, S. M.; Singh, Bijendra

    2016-07-01

    The paper describes an experimental study aimed at suppressing stress corrosion cracking susceptibility of machined 304L stainless steel specimens through laser shock peening. The study also evaluates a new approach of oblique laser shock peening to suppress stress corrosion cracking susceptibility of internal surface of type 304L stainless steel tube. The results of the study, performed with an indigenously developed 2.5 J/7 ns Nd:YAG laser, demonstrated that laser shock peening effectively suppresses chloride stress corrosion cracking susceptibility of machined surface of type 304L stainless steel. In the investigated range of incident laser power density (3.2-6.4 GW/cm2), machined specimens peened with power density of 4.5 and 6.4 GW/cm2 displayed lower stress corrosion cracking susceptibility considerably than those treated with 3.2 and 3.6 GW/cm2 in boiling magnesium chloride test. Oblique laser shock peening, performed on machined internal surface of a type 304L stainless steel tube (OD = 111 mm; ID = 101 mm), was successful in introducing residual compressive surface stresses which brought about significant suppression of its stress corrosion cracking susceptibility. The technique of oblique laser shock peening, in spite of its inherent limitations on the length of peened region being limited by tube internal diameter and the need for access from both the sides, presents a simplified approach for peening internal surface of small tubular components.

  14. Weld solidification cracking in 304 to 304L stainless steel

    SciTech Connect

    Hochanadel, Patrick W; Lienert, Thomas J; Martinez, Jesse N; Martinez, Raymond J; Johnson, Matthew Q

    2010-01-01

    A series of annulus welds were made between 304 and 304L stainless steel coaxial tubes using both pulsed laser beam welding (LBW) and pulsed gas tungsten arc welding (GTAW). In this application, a change in process from pulsed LBW to pulsed gas tungsten arc welding was proposed to limit the possibility of weld solidification cracking since weldability diagrams developed for GTAW display a greater range of compositions that are not crack susceptible relative to those developed for pulsed LBW. Contrary to the predictions of the GTAW weldability diagram, cracking was found. This result was rationalized in terms of the more rapid solidification rate of the pulsed gas tungsten arc welds. In addition, for the pulsed LBW conditions, the material compositions were predicted to be, by themselves, 'weldable' according to the pulsed LBW weldability diagram. However, the composition range along the tie line connecting the two compositions passed through the crack susceptible range. Microstructurally, the primary solidification mode (PSM) of the material processed with higher power LBW was determined to be austenite (A), while solidification mode of the materials processed with lower power LBW apparently exhibited a dual PSM of both austenite (A) and ferrite-austenite (FA) within the same weld. The materials processed by pulsed GT A W showed mostly primary austenite solidification, with some regions of either primary austenite-second phase ferrite (AF) solidification or primary ferrite-second phase austenite (FA) solidification. This work demonstrates that variations in crack susceptibility may be realized when welding different heats of 'weldable' materials together, and that slight variations in processing can also contribute to crack susceptibility.

  15. Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments

    DOE PAGESBeta

    Sun, C.; Zheng, S.; Wei, C. C.; Wu, Y.; Shao, L.; Yang, Y.; Hartwig, K. T.; Maloy, S. A.; Zinkle, S. J.; Allen, T. R.; et al

    2015-01-15

    Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304L SS with an average grain size ofmore » ~100 nm, can withstand Fe ion irradiation at 500°C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M₂₃C₆ precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.« less

  16. Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments

    PubMed Central

    Sun, C.; Zheng, S.; Wei, C. C.; Wu, Y.; Shao, L.; Yang, Y.; Hartwig, K. T.; Maloy, S. A.; Zinkle, S. J.; Allen, T. R.; Wang, H.; Zhang, X.

    2015-01-01

    Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500°C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M23C6 precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments. PMID:25588326

  17. Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments

    SciTech Connect

    Sun, C.; Zheng, S.; Wei, C. C.; Wu, Y.; Shao, L.; Yang, Y.; Hartwig, K. T.; Maloy, S. A.; Zinkle, S. J.; Allen, T. R.; Wang, H.; Zhang, X.

    2015-01-15

    Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500°C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M₂₃C₆ precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.

  18. Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments.

    PubMed

    Sun, C; Zheng, S; Wei, C C; Wu, Y; Shao, L; Yang, Y; Hartwig, K T; Maloy, S A; Zinkle, S J; Allen, T R; Wang, H; Zhang, X

    2015-01-01

    Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304 L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500 °C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M(23)C(6) precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments. PMID:25588326

  19. Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments

    NASA Astrophysics Data System (ADS)

    Sun, C.; Zheng, S.; Wei, C. C.; Wu, Y.; Shao, L.; Yang, Y.; Hartwig, K. T.; Maloy, S. A.; Zinkle, S. J.; Allen, T. R.; Wang, H.; Zhang, X.

    2015-01-01

    Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500°C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M23C6 precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.

  20. On the dynamic strength of 304l stainless steel under impact

    NASA Astrophysics Data System (ADS)

    Werdiger, Meir; Glam, Benny; Bakshi, Lior; Moshe, Ella; Horovitz, Yossef; Pistinner, Shlomi Levi

    2012-03-01

    Uniaxial strain plane impact (300-1700 m/s), loading and reloading experiments carried out on SS304L are reported. The aim of these experiments was to measure the material strength properties under shock compression. Most of the experiments reported here show a viscous type elastic precursor. The experimental results are compared to numerical simulations performed using a 1D code. The input physics to the simulations are the Steinberg equation of state and Johnson-Cook strength model. This model has been previously calibrated under uniaxial stress conditions in the rangee ɛ =1-5×103 s-1. Our experiments extended the data into the regione ɛ =105 -106 s-1. In spite of this extrapolation, there is a general agreement between simulations and experiments. However, differences in some details still exist.

  1. Characterizing pre-polished Type 304L stainless steel

    SciTech Connect

    Hsu, R.H.; Summer, M.E.; Rankin, W.N.

    1994-10-01

    Prepolished Type 304L stainless steel surfaces are being specified for replacement of some equipment in the 221-H Canyon Building at the Savannah River Site. A prepolished stainless steel surface picks up less contamination than a hot-rolled and pickled surface and is easier to decontaminate; therefore, less waste is generated. Surface-characterization techniques and specification for a prepolished surface were developed to ensure that prepolished items being obtained were properly electropolished. The use of this technology has resulted in obtaining prepolished items with an improved surface finish.

  2. Microstructures of laser deposited 304L austenitic stainless steel

    SciTech Connect

    BROOKS,JOHN A.; HEADLEY,THOMAS J.; ROBINO,CHARLES V.

    2000-05-22

    Laser deposits fabricated from two different compositions of 304L stainless steel powder were characterized to determine the nature of the solidification and solid state transformations. One of the goals of this work was to determine to what extent novel microstructure consisting of single-phase austenite could be achieved with the thermal conditions of the LENS [Laser Engineered Net Shape] process. Although ferrite-free deposits were not obtained, structures with very low ferrite content were achieved. It appeared that, with slight changes in alloy composition, this goal could be met via two different solidification and transformation mechanisms.

  3. Nano-cavities observed in a 316SS PWR Flux Thimble Tube Irradiated to 33 and 70 dpa

    SciTech Connect

    Edwards, Danny J.; Garner, Francis A.; Bruemmer, Stephen M.; Efsing, Pal G.

    2009-02-28

    The radiation-induced microstructure of a cold-worked 316SS flux thimble tube from an operating pressurized water reactor (PWR) was examined. Two irradiated conditions, 33 dpa at 290ºC and 70 dpa at 315ºC were examined by transmission electron microscopy. The original dislocation network had completely disappeared and was replaced by fine dispersions of Frank loops and small nano-cavities at high densities. The latter appear to be bubbles containing high levels of helium and hydrogen. An enhanced distribution of these nano-cavities was found at grain boundaries and may play a role in the increased susceptibility of the irradiated 316SS to intergranular failure of specimens from this tube during post-irradiation slow strain rate testing in PWR water conditions.

  4. Weldability of tritium-charged 304L stainless steel

    SciTech Connect

    Kanne, W R; Angerman, C L; Eberhard, B J

    1987-02-01

    Attempts to repair the wall of C-Reactor Tank at the Savannah River Plant were halted when Gas Tungsten Arc (GTA) welds joining patches to the wall developed toe cracks in the heat affected zone (HAZ). The cause of the toe cracks was investigated by welding on 304L samples that were tritium charged and aged to produce helium. Helium embrittlement was shown to be the likely cause of weld toe cracking in C-Reactor Tank. GTA welds made on helium impregnated 304L produced toe cracks identical to those that caused leaking patches during C-Reactor Tank repair. Heating of a sample to remove deuterium and tritium without removing helium did not reduce cracking susceptibility. Low heat input and spot GTA welds also produced cracks, indicating possible problems using these techniques for reactor repair. However, cracks were not produced by solid state resistance welds, or by a very low heat GTA pass that did not produce melting. This indicates that non-melting or low tensile stress techniques could be used for repair.

  5. Abnormal grain growth in AISI 304L stainless steel

    SciTech Connect

    Shirdel, M.; Mirzadeh, H.; Parsa, M.H.

    2014-11-15

    The microstructural evolution during abnormal grain growth (secondary recrystallization) in 304L stainless steel was studied in a wide range of annealing temperatures and times. At relatively low temperatures, the grain growth mode was identified as normal. However, at homologous temperatures between 0.65 (850 °C) and 0.7 (900 °C), the observed transition in grain growth mode from normal to abnormal, which was also evident from the bimodality in grain size distribution histograms, was detected to be caused by the dissolution/coarsening of carbides. The microstructural features such as dispersed carbides were characterized by optical metallography, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and microhardness. Continued annealing to a long time led to the completion of secondary recrystallization and the subsequent reappearance of normal growth mode. Another instance of abnormal grain growth was observed at homologous temperatures higher than 0.8, which may be attributed to the grain boundary faceting/defaceting phenomenon. It was also found that when the size of abnormal grains reached a critical value, their size will not change too much and the grain growth behavior becomes practically stagnant. - Highlights: • Abnormal grain growth (secondary recrystallization) in AISI 304L stainless steel • Exaggerated grain growth due to dissolution/coarsening of carbides • The enrichment of carbide particles by titanium • Abnormal grain growth due to grain boundary faceting at very high temperatures • The stagnancy of abnormal grain growth by annealing beyond a critical time.

  6. Corrosion of 304L and 316 in gadolinium nitrate neutron poison solutions

    SciTech Connect

    Chandler, G.T.; Anderson, M.H.

    1991-12-31

    Pitting corrosion has occurred on AISI Type 304L stainless steel (304L) conductivity probes used to monitor liquid levels of gadolinium nitrate neutron poison solutions (GPS). An electrochemical and immersion test program has led to a better understanding of the cause of corrosion of 304L probes. Results indicate that the alternating voltage applied to the probes to monitor contact with solution is the primary factor in the corrosion of the probes. A chloride-containing dye and low pH also contribute to the corrosion process, but appear to play a secondary role. AISI Type 316 stainless steel (316) was found to behave similarly to 304L in GPS, while nickel-based alloys such as Hastelloy G30, Hastelloy C22, and Inconel 625 were found to be more susceptible to corrosion as compared to 304L.

  7. Corrosion of 304L and 316 in gadolinium nitrate neutron poison solutions

    SciTech Connect

    Chandler, G.T.; Anderson, M.H.

    1991-01-01

    Pitting corrosion has occurred on AISI Type 304L stainless steel (304L) conductivity probes used to monitor liquid levels of gadolinium nitrate neutron poison solutions (GPS). An electrochemical and immersion test program has led to a better understanding of the cause of corrosion of 304L probes. Results indicate that the alternating voltage applied to the probes to monitor contact with solution is the primary factor in the corrosion of the probes. A chloride-containing dye and low pH also contribute to the corrosion process, but appear to play a secondary role. AISI Type 316 stainless steel (316) was found to behave similarly to 304L in GPS, while nickel-based alloys such as Hastelloy G30, Hastelloy C22, and Inconel 625 were found to be more susceptible to corrosion as compared to 304L.

  8. The effect of stress-state on the large strain inelastic deformation behavior of 304L stainless steel

    SciTech Connect

    Miller, M.P.; McDowell, D.L.

    1996-01-01

    In metals, large strain inelastic deformation processes such as the formation of a preferred crystallographic orientation (crystallographic texture) and strain hardening processes such as the formation and evolution of dislocation substructures depend on stress-state. Much of the current large strain research has focused on texture. Crystallographic texture development and strain-hardening processes each contribute to the overall material behavior, and a complete description of large strain inelastic material response should reflect both. An investigation of the large strain behavior of 304L stainless steel (SS 304L) subjected to compression, torsion, and sequences of compression followed by torsion and torsion followed by tension is reported. This paper focuses on the stress-state dependence of strain-hardening processes as well as the relative effect such processes have on the overall material behavior. To characterize these processes, transmission electron microscopy (TEM) as well as magnetization investigations were conducted at different strain levels and under different deformation modes. The {gamma} {yields} {alpha}{prime} martensitic transformation which occurs in this material was found to be related to both the strain level and stress state. Dislocation substructures in the form of Taylor lattices, dense dislocation walls, and microbands were also present. The ramifications of using a thin-walled tubular torsion specimen were also explored.

  9. Thermomechanical history measurements on Type 304L stainless steel pipe girth welds

    SciTech Connect

    Li, Ming; Atteridge, D.G.; Anderson, W.E.; Turpin, R.; West, S.L.

    1993-12-31

    Thermal and strain histories were recorded for three 40-cm-diameter (16 inch), Type 304L stainless steel (SS), schedule 40 (1.27 cm thickness) pipe girth welds. Two weld groove preparations were standard V grooves while the third was a narrow groove configuration. The welding parameters for the three pipe welds simulated expected field practice as closely as possible. The narrow gap weld was completed in four continuous passes while the other two welds required six and nine (discontinuous) passes, due to the use of different weld wire diameters. Thermomechanical history measurements were taken on the inner counterbore surface, encompassing the weld centerline and heat-affected zone (HAZ), as well as 10 cm of inner counterbore surface on either side of the weld centerline; a total of 47 data acquisition instruments were used for each weld. These instruments monitored: (1) weld shrinkages parallel to the pipe axis; (2) surface temperatures; (3) surface strains parallel to weld centerline; and (4) radial deformations. Results show that the weld and HAZ experienced cyclic deformation in the radial direction during welding, indicating that the final residual stress distribution in multi-pass pipe weldments is not axisymmetric. Measured radial and axial deformations were smaller for the narrow gap groove than for the standard V grooves, suggesting that the narrow gap groove weldment may have lower residual stress levels than the standard V groove weldments. This study provides the experimental database and a guideline for further computational modeling work.

  10. High temperature oxidation behavior of AISI 304L stainless steel-Effect of surface working operations

    NASA Astrophysics Data System (ADS)

    Ghosh, Swati; Kumar, M. Kiran; Kain, Vivekanand

    2013-01-01

    The oxidation behavior of grade 304L stainless steel (SS) subjected to different surface finishing (machining and grinding) operations was followed in situ by contact electric resistance (CER) and electrochemical impedance spectroscopy (EIS) measurements using controlled distance electrochemistry (CDE) technique in high purity water (conductivity < 0.1 μS cm-1) at 300 °C and 10 MPa in an autoclave connected to a recirculation loop system. The results highlight the distinct differences in the oxidation behavior of surface worked material as compared to solution annealed material in terms of specific resistivity and low frequency Warburg impedance. The resultant oxide layer was characterized for (a) elemental analyses by glow discharge optical emission spectroscopy (GDOES) and (b) morphology by scanning electron microscopy (SEM). Oxide layers with higher specific resistivity and chromium content were formed in case of machined and ground conditions. Presence of an additional ionic transport process has also been identified for the ground condition at the metal/oxide interface. These differences in electrochemical properties and distinct morphological features of the oxide layer as a result of surface working were attributed to the prevalence of heavily fragmented grain structure and presence of martensite.

  11. Corrosion study of stainless steel SS304L in molten molybdates

    NASA Astrophysics Data System (ADS)

    Usami, T.; Uruga, K.; Tsukada, T.; Miura, Y.; Komamine, S.; Ochi, E.

    2016-04-01

    Depending on operating conditions of the vitrification process of high-level liquid waste, molten salt mainly composed of sodium and molybdenum can be generated, and poured into stainless steel canisters. In this work, the possible reaction between the molten molybdate and stainless steel was investigated using multi-component molybdate and simple Na2MoO4 - MoO3 molybdate. In the experiments using multi-component molybdates, no significant reaction is observed between the mixed molybdates and the stainless steel specimens at 700 °C in 4 h. The reaction rate of the stainless steel with the multi-component molybdate increases in proportion to exp(-1/T). The depth of the most reacted area is about 300 μm even at 1000 °C, and was much smaller than the 6 mm thickness of the canister. In the simple Na2MoO4 - MoO3 molybdate, the reaction rate was proportional to the MoO3 concentration. The essence of the reaction is oxidation of metals by Mo6+ - > Mo4+. Part of the reaction product mainly composed of Fe is dissolved into the molybdate, while the other part mainly composed of Cr sloughs and forms a banded layer.

  12. HYDROGEN-ASSISTED FRACTURE IN FORGED TYPE 304L AUSTENITIC STAINLESS STEEL

    SciTech Connect

    Switzner, Nathan; Neidt, Ted; Hollenbeck, John; Knutson, J.; Everhart, Wes; Hanlin, R.; Bergen, R.; Balch, D. K.

    2012-09-06

    Austenitic stainless steels generally have good resistance to hydrogen-assisted fracture; however, structural designs for high-pressure gaseous hydrogen are constrained by the low strength of this class of material. Forging is used to increase the low strength of austenitic stainless steels, thus improving the efficiency of structural designs. Hydrogen-assisted racture, however, depends on microstructural details associated with manufacturing. In this study, hydrogen-assisted fracture of forged type 304L austenitic stainless steel is investigated. Microstructural variation in multi-step forged 304L was achieved by forging at different rates and temperatures, and by process annealing. High internal hydrogen content in forged type 304L austenitic stainless steel is achieved by thermal precharging in gaseous hydrogen and results in as much as 50% reduction of tensile ductility.

  13. Texture evolution of warm-rolled and annealed 304L and 316L austenitic stainless steels

    NASA Astrophysics Data System (ADS)

    Lindell, D.

    2015-04-01

    The brass-to-copper rolling texture transition is observed during warm rolling austenitic stainless steels. In the current paper austenitic stainless steels 304L and 316L have been subjected to warm rolling at 700°C to 90% reduction. The evolution of microstructure and texture during subsequent annealing has been studied using dilatometry and electron backscatter diffraction. Recrystallisation texture for 304L was primarily cube with some retained rolling texture while 316L only had retained rolling texture. The different behaviour between the two steels is believed to originate from differences in molybdenum content.

  14. Corrosion testing of Type 304L stainless steel for waste tank applications

    SciTech Connect

    Wiersma, B.J.; Mickalonis, J.I.

    1991-12-31

    AISI Type 304L stainless steel will be the material of construction for hazardous waste storage tanks. The corrosion behavior of 304L was characterized in simulated waste solutions using potentiodynamic polarization, electrochemical impedance spectroscopy and long term immersion tests. The results were correlated to assess the use of corrosion characteristics determined by electrochemical techniques for predicting long term corrosion behavior. The corrosion behaviors of Type A537 carbon steel and Incoloy 825 were also evaluated. A good correlation was found between the results from the electrochemical techniques and the immersion tests.

  15. Corrosion testing of Type 304L stainless steel for waste tank applications

    SciTech Connect

    Wiersma, B.J.; Mickalonis, J.I.

    1991-01-01

    AISI Type 304L stainless steel will be the material of construction for hazardous waste storage tanks. The corrosion behavior of 304L was characterized in simulated waste solutions using potentiodynamic polarization, electrochemical impedance spectroscopy and long term immersion tests. The results were correlated to assess the use of corrosion characteristics determined by electrochemical techniques for predicting long term corrosion behavior. The corrosion behaviors of Type A537 carbon steel and Incoloy 825 were also evaluated. A good correlation was found between the results from the electrochemical techniques and the immersion tests.

  16. Characterization of the deformation and annealing of 304L stainless steel. Final report

    SciTech Connect

    Smith, W.H.

    1994-08-01

    Stainless steel, type 304L, was deformed at room temperature using the two processes of semi-piercing and cold-rolling and then annealed at various temperatures and times. The three metallurgical areas of work hardening, age hardening, and anneal softening were observed and characterized using metallography techniques of macrohardness, optical and transmission electron microscopy, and X-ray diffraction.

  17. Stress corrosion cracking of type 304L stainless steel core shroud welds.

    SciTech Connect

    Chung, H. M.; Park, J.-H.; Sanecki, J. E.; Zaluzec, N. J.; Yu, M. S.; Yang, T. T.

    1999-10-26

    Microstructural analyses by advanced metallographic techniques were conducted on mockup welds and a cracked BWR core shroud weld fabricated from Type 304L stainless steel. heat-affected zones of the shroud weld and mockup shielded-metal-arc welds were free of grain-boundary carbide, martensite, delta ferrite, or Cr depletion near grain boundaries. However, as a result of exposure to welding fumes, the heat-affected zones of the welds were significantly contaminated by fluorine and oxygen which migrate to grain boundaries. Significant oxygen contamination promotes fluorine contamination and suppresses classical thermal sensitization, even in Type 304 steels. Results of slow-strain-rate tensile tests indicate that fluorine exacerbates the susceptibility of irradiated steels to intergranular stress corrosion cracking. These observations, combined with previous reports on the strong influence of weld flux, indicate that oxygen and fluorine contamination and fluorine-catalyzed stress corrosion play a major role in cracking of Type 304L stainless steel core shroud welds.

  18. TESTING OF 304L STAINLESS STEEL IN NITRIC ACID ENVIRONMENTS WITH FLUORIDES AND CHLORIDES

    SciTech Connect

    Mickalonis, J.

    2010-10-04

    Impure radioactive material processed in nitric acid solutions resulted in the presence of chlorides in a dissolver fabricated from 304L stainless steel. An experimental program was conducted to study the effects of chloride in nitric acid/fluoride solutions on the corrosion of 304L stainless steel. The test variables included temperature (80, 95, and 110 C) and the concentrations of nitric acid (6, 12, and 14 M), fluoride (0.01, 0.1, and 0.2 M) and chloride (100, 350, 1000, and 2000 ppm). The impact of welding was also investigated. Results showed that the chloride concentration alone was not a dominant variable affecting the corrosion, but rather the interaction of chloride with fluoride significantly affected corrosion.

  19. Tritium permeation through characterized films on Type 304L stainless steel

    SciTech Connect

    Kallas, A.J.; Rising, T.L.; Childs, E.L.; Thomas, R.L.

    1987-07-24

    Rocky Flats is looking for an optimum method for surface treating 304L stainless steel to increase its resistance to tritium permeation. Selected surface treatments were applied to 304L samples. One set of samples was shipped to the Rockwell Corporate Science Center for alternate characterization analysis. Another set was sent to Los Alamos National Laboratory for tritium exposure and ion beam spectrographic analysis. The Science Center performed the following analyses: ellipsometry, contact potential, photoelectron emission, surface energy, surface activation, cathodic polarization, electrochemical impedance, and open-circuit potential. Excellent correlation was found between type of treatment and surface activation and electrochemical impedance. Results of the Science Center tests correlated well with actual tritium permeation measurements made at Los Alamos. 8 refs., 8 figs., 1 tab.

  20. Temperature effects on the mechanical properties of annealed and HERF 304L stainless steel.

    SciTech Connect

    Antoun, Bonnie R.

    2004-11-01

    The effect of temperature on the tensile properties of annealed 304L stainless steel and HERF 304L stainless steel forgings was determined by completing experiments over the moderate range of -40 F to 160 F. Temperature effects were more significant in the annealed material than the HERF material. The tensile yield strength of the annealed material at -40 F averaged twenty two percent above the room temperature value and at 160 F averaged thirteen percent below. The tensile yield strength for the three different geometry HERF forgings at -40 F and 160 F changed less than ten percent from room temperature. The ultimate tensile strength was more temperature dependent than the yield strength. The annealed material averaged thirty six percent above and fourteen percent below the room temperature ultimate strength at -40 F and 160 F, respectively. The HERF forgings exhibited similar, slightly lower changes in ultimate strength with temperature. For completeness and illustrative purposes, the stress-strain curves are included for each of the tensile experiments conducted. The results of this study prompted a continuation study to determine tensile property changes of welded 304L stainless steel material with temperature, documented separately.

  1. Texture and Yield Stress of Pre-Strained 304L Stainless Steel

    SciTech Connect

    Bennett, K.; Von Dreele, B.; Gray, G.T. III; Chen, S.R.

    1997-06-23

    The evolution of texture and yield stress in 304L stainless steel is investigated as a function of deformation to large plastic strains. Steel bars quasi-statically upset forged at a strain rate of 0.001s{sup -1} to true strains of 0, 0.5, 1.0 and 1.8 were found to acquire their texture ({approximately}3.0 m.r.d.) in the first 0.5 strain with (110) poles highly aligned parallel to the compression direction independent of whether the pre-forged starting material was in a cold worked or annealed (1050 C for 1 hour) condition. The same bars, when strained at room temperature show an incremental yield with pre-strain regardless of strain rate (10{sup -1} or 10{sup -3}s{sup -1}) or thermal history, though annealed bars yield at slightly lower stresses. At 77 K and strain rate 10{sup -3}s{sup -1}, the annealed 304L exhibits more pronounced strain-hardening behavior than the 304L forged in a cold-worked condition.

  2. Comparative Shock Response of Additively Manufactured Versus Conventionally Wrought 304L Stainless Steel*

    NASA Astrophysics Data System (ADS)

    Wise, J. L.; Adams, D. P.; Nishida, E. E.; Song, B.; Maguire, M. C.; Carroll, J.; Reedlunn, B.; Bishop, J. E.

    2015-06-01

    Gas-gun experiments have probed the compression and release behavior of impact-loaded 304L stainless steel specimens machined from additively manufactured (AM) blocks as well as baseline ingot-derived bar stock. The AM technology allows direct fabrication of metal parts. For the present study, a velocity interferometer (VISAR) measured the time-resolved motion of samples subjected to one-dimensional (i.e., uniaxial strain) shock compression to peak stresses ranging from 0.2 to 7.5 GPa. The acquired wave-profile data have been analyzed to determine the comparative Hugoniot Elastic Limit (HEL), Hugoniot equation of state, spall strength, and high-pressure yield strength of the AM and conventional materials. Observed differences in shock loading and unloading characteristics for the two 304L source variants have been correlated to complementary Kolsky bar results for compressive and tensile testing at lower strain rates. The effects of composition, porosity, microstructure (e.g., grain size and morphology), residual stress, and sample axis orientation relative to the additive manufacturing deposition trajectory have been assessed to explain differences between the AM and baseline 304L dynamic mechanical properties. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  3. Multitechnique characterisation of 304L surface states oxidised at high temperature in steam and air atmospheres

    NASA Astrophysics Data System (ADS)

    Mamede, Anne-Sophie; Nuns, Nicolas; Cristol, Anne-Lise; Cantrel, Laurent; Souvi, Sidi; Cristol, Sylvain; Paul, Jean-François

    2016-04-01

    In case of a severe accident occurring in a nuclear reactor, surfaces of the reactor coolant system (RCS), made of stainless steel (304L) rich in Cr (>10%) and Ni (8-12%), are oxidised. Fission products (FPs) are released from melt fuel and flow through the RCS. A part of them is deposited onto surfaces either by vapour condensation or by aerosol deposition mechanisms. To be able to understand the nature of interactions between these FPs and the RCS surfaces, a preliminary step is to characterize the RSC surface states in steam and air atmosphere at high temperatures. Pieces of 304L stainless steel have been treated in a flow reactor at two different temperatures (750 °C and 950 °C) for two different exposition times (24 h and 72 h). After surfaces analysing by a unique combination of surface analysis techniques (XPS, ToF-SIMS and LEIS), for 304L, the results show a deep oxide scale with multi layers and the outer layer is composed of chromium and manganese oxides. Oxide profiles differ in air or steam atmosphere. Fe2O3 oxide is observed but in minor proportion and in all cases no nickel is detected near the surface. Results obtained are discussed and compared with the literature data.

  4. Texture and yield stress of pre-strained 304L stainless steel

    SciTech Connect

    Bennett, K.; Dreele, R.B. von; Gray, G.T. III; Chen, S.R.

    1998-08-01

    The evolution of texture and yield stress in 304L stainless steel is investigated as a function of deformation to large plastic strains. Steel bars quasi-statically upset forged at a strain rate of 0.001 s{sup {minus}1} to true strains of 0, 0.5, 1.0 and 1.8 were found to acquire their texture ({approximately}3.0 m.r.d.) in the first 0.5 strain with (110) poles highly aligned parallel to the compression direction independent of whether the pre-forged starting material was in a cold worked or annealed (1,050 C for 1 hour) condition. The same bars, when strained at room temperature show an incremental yield with pre-strain regardless of strain rate (10{sup {minus}1} or 10{sup {minus}3}s{sup {minus}1}) or thermal history, though annealed bars yield at slightly lower stresses. At 77 K and strain rate 10{sup {minus}3}s{sup {minus}1}, the annealed 304L exhibits more pronounced strain-hardening behavior than the 304L forged in a cold-worked condition.

  5. Corrosion-resistant tube materials for extended life of openings in recovery boilers

    SciTech Connect

    Paul, L.D.; Danielson, M.J.; Harper, S.L. . Research and Development Div.); Barna, J.L. . Fossil Power Div.)

    1993-08-01

    The corrosive conditions causing rapid corrosion of Type 304L stainless steel in tube openings have been duplicated in the laboratory. Alternate materials also have been tested, and some show improved corrosion resistance over Type 304L. Alloy 825 and Alloy 625 composite tubing and Alloy 600 and Alloy 625 weld overlay materials all show promise as a replacement for Type 304L in tube openings. All recovery boilers designed or operated at 8.375 MPa (1,200 psi) and above should consider using these replacement materials for tube openings.

  6. Effect of tin addition on the microstructure development and corrosion resistance of sintered 304L stainless steels

    SciTech Connect

    Wang, W.F.

    1999-12-01

    The effect of tin powder addition on the microstructure development during sintering and corrosion resistance of the 304L-Sn metallurgical system was investigated. Specimens containing 1 to 4 wt% Sn were sintered in hydrogen at temperatures ranging from 800 to 1,300 C. During sintering at temperatures below 1,000 C, most of the liquid phase was retained at the site originally occupied by the tin powder. At temperatures above 1,050 C, the tin-base liquid phase spread and uniformly distributed among the 304L solid particles. Adding tin powder and the resultant liquid phase led 304L powder compacts to expand during sintering. An immersion test in 1 M H{sub 2}SO{sub 4} and metallographic observation showed that pitting always initiated at the spots with lower tin content, and the tin atom enrichment had the beneficial effect of improving the corrosion resistance of sintered 304L stainless steels.

  7. Studies of Degraded Smelt Spout Opening Tubes

    SciTech Connect

    Keiser, James R; Kish, Joseph R.; Willoughby, Adam W; Longmire, Hu Foster; Singbeil, Douglas

    2007-01-01

    Co-extruded type 304L stainless steel/SA210 carbon steel tubes have been used on the floors and lower walls of many black liquor recovery boilers to address the wall thinning problem that had been an issue for boiler owners and operators. Use of these tubes greatly reduced the corrosion issue, but corrosion was still sometimes observed and cracking was discovered in some tubes, particularly those that are bent to form the openings for smelt spouts. Because cracks in the opening tubes were sometimes observed to extend a significant distance into the tube wall and because these cracks were found fairly frequently, tubes made from a number of alternate cladding materials were tried in place of the 304L clad opening tubes. This paper describes the results of examinations of spout opening tubes of the standard 304L/carbon steel and of several of the alternate materials that have been tried. In addition to the corrosion and cracking seen in the spout opening tubes, another issue associated with these tubes has been observed. Preferential corrosion of the cap welds is sometimes seen on butt welds attaching the spout opening tubes made with alternate cladding materials to the standard 304L/carbon steel co-extruded wall tubes. Some information on the observations of this corrosion is also included in this paper.

  8. Upset welded 304L and 316L vessels for storage tests

    SciTech Connect

    Kanne, W.R. Jr.

    1996-04-01

    Two sets of vessels for tritium storage tests were fabricated using upset welding. A solid-state resistance upset weld was used to join the two halves of each vessel at the girth. The vessels differ from production reservoirs in design, material, and fabrication process. One set was made from forged 304L stainless steel and the other from forged 316L stainless steel. Six vessels of each type were loaded with a tritium mix in November 1995 and placed in storage at 71 C. This memo describes and documents the fabrication of the twelve vessels.

  9. Comparison of Stress Corrosion Cracking Susceptibility of Laser Machined and Milled 304 L Stainless Steel

    NASA Astrophysics Data System (ADS)

    Gupta, R. K.; Kumar, Aniruddha; Nagpure, D. C.; Rai, S. K.; Singh, M. K.; Khooha, Ajay; Singh, A. K.; Singh, Amrendra; Tiwari, M. K.; Ganesh, P.; Kaul, R.; Singh, B.

    2016-07-01

    Machining of austenitic stainless steel components is known to introduce significant enhancement in their susceptibility to stress corrosion cracking. The paper compares stress corrosion cracking susceptibility of laser machined 304 L stainless steel specimens with conventionally milled counterpart in chloride environment. With respect to conventionally milled specimens, laser machined specimens displayed more than 12 times longer crack initiation time in accelerated stress corrosion cracking test in boiling magnesium chloride as per ASTM G36. Reduced stress corrosion cracking susceptibility of laser machined surface is attributed to its predominantly ferritic duplex microstructure in which anodic ferrite phase was under compressive stress with respect to cathodic austenite.

  10. Quantification of stress history in type 304L stainless steel using positron annihilation spectroscopy

    SciTech Connect

    Walters, Thomas W.; Walters, Leon C.; Schoen, Marco P.; Naidu, D. Subbaram; Dickerson, Charles; Perrenoud, Ben C.

    2011-04-15

    Five Type 304L stainless steel specimens were subjected to incrementally increasing values of plastic strain. At each value of strain, the associated static stress was recorded and the specimen was subjected to positron annihilation spectroscopy (PAS) using the Doppler Broadening method. A calibration curve for the 'S' parameter as a function of stress was developed based on the five specimens. Seven different specimens (blind specimens labeled B1-B7) of 304L stainless steel were subjected to values of stress inducing plastic deformation. The values of stress ranged from 310 to 517 MPa. The seven specimens were subjected to PAS post-loading using the Doppler Broadening method, and the results were compared against the developed curve from the previous five specimens. It was found that a strong correlation exists between the 'S' parameter, stress, and strain up to a strain value of 15%, corresponding to a stress value of 500 MPa, beyond which saturation of the 'S' parameter occurs. Research Highlights: {yields} Specimens were initially in an annealed/recrystallized condition. {yields} Calibration results indicate positron annihilation measurements yield correlation. {yields} Deformation produced by cold work was likely larger than the maximum strain.

  11. Modeling Periodic Adiabatic Shear Bands Evolution in a 304L Stainless Steel Thick-Walled Cylinder

    NASA Astrophysics Data System (ADS)

    Liu, Mingtao; Hu, Haibo; Fan, Cheng; Tang, Tiegang

    2015-06-01

    The self-organization of multiple shear bands in a 304L stainless steel thick-walled cylinder (TWC) was numerically studied. The microstructures of material lead to the non-uniform distribution of local yield stress, which plays a key role in the formation of spontaneous shear localization. We introduced a probability factor satisfied Gauss distribution into the macroscopic constitutive relationship to describe the non-uniformity of local yield stress. Using the probability factor, the initiation and propagation of multiple shear bands in TWC were numerically replicated in our 2D FEM simulation. Experimental results in the literature indicate that the machined surface at the internal boundary of a 304L stainless steel cylinder provides a work-hardened layer (about 20 μm) which has significantly different microstructures from base material. The work-hardened layer leads to the phenomenon that most shear bands are in clockwise or counterclockwise direction. In our simulation, periodic oriented perturbations were applied to describe the grain orientation in the work-hardened layer, and the spiral pattern of shear bands was successfully replicated.

  12. Environmental resistance of oxide tags fabricated on 304L stainless steel via nanosecond pulsed laser irradiation

    DOE PAGESBeta

    Lawrence, Samantha Kay; Adams, David P.; Bahr, David F.; Moody, Neville R.

    2015-11-14

    Nanosecond pulsed laser irradiation was used to fabricate colored, mechanically robust oxide “tags” on 304L stainless steel. Immersion in simulated seawater solution, salt fog exposure, and anodic polarization in a 3.5% NaCl solution were employed to evaluate the environmental resistance of these oxide tags. Single layer oxides outside a narrow thickness range (~ 100–150 nm) are susceptible to dissolution in chloride containing environments. The 304L substrates immediately beneath the oxides corrode severely—attributed to Cr-depletion in the melt zone during laser processing. For the first time, multilayered oxides were fabricated with pulsed laser irradiation in an effort to expand the protectivemore » thickness range while also increasing the variety of film colors attainable in this range. Layered films grown using a laser scan rate of 475 mm/s are more resistant to both localized and general corrosion than oxides fabricated at 550 mm/s. Furthermore, in the absence of pre-processing to mitigate Cr-depletion, layered films can enhance environmental stability of the system.« less

  13. SCC Propagation Rate of Type 304, 304L Steels Under Oceanic Air Environment

    SciTech Connect

    Akio Kosaki

    2006-07-01

    Corrosion integrity of canister in the concrete cask for spent fuel storage is very important because the canister serves to maintain the sealability over the storage period of 40 to 60 years. Natural exposure and accelerated corrosion tests of conventional stainless steels for canister, that are Type 304, 304L, and 316(LN), for concrete cask's canister have been conducted by using many three Point Bending (3PB) test specimens and compared. The SCC propagation rates in Type 304 and 304L at the natural condition were about 1.2 E-12 to 1.8 E-11 m/s at the K (Stress Intensity Factor) range of 0.6 to 9.0 MPa/m, and that of the accelerate test (60 degrees C, 95%RHS., filled with NaCl mist.) were about 1.0 E-10 to 3.5 E-9 m/s at the K range of 0.3 to 32 MPa/m. The SCC propagation rates under both natural and accelerated conditions were independent with K. Both da/dt values of the direct exposure test and of the under glass exposure test were in the same scattering band. (author)

  14. Grain boundary character modification employing thermo-mechanical processing in type 304L stainless steel

    NASA Astrophysics Data System (ADS)

    Pradhan, S. K.; Mandal, S.

    2016-02-01

    Grain boundary engineering (GBE) approach has been employed to modify the boundaries character of a type 304L stainless steel through thermo-mechanical processing (TMP) route, which combined a low level of cold deformation (5, 10 and 15%) followed by annealing at 1173K and 1273K for 1hour. Employing Electron Back Scatter Diffraction based Orientation Imaging Microscopy, the fraction and distribution of low ∑ CSL boundaries (∑≤ 29) and its effect on random high-angle grain boundaries connectivity and triple junction distribution of as-received (AR) and GBE specimens were evaluated. It was possible to increase the fraction of low ∑ CSL boundaries up to 75% following GBE treatment (as compared to 50% in AR specimen). The GBE specimens also contained maximum number of percolation resistant triple junctions which could render better resistance against percolation related phenomena.

  15. Type 304L stainless steel surface microstructure: Performance in hydride storage and acid cleaning

    SciTech Connect

    Clark, E.A.

    1994-07-01

    The performance of stainless steel as the container in hydride storage bed systems has been evaluated, primarily using scanning electron microscopy. No adverse reaction between Type 304L stainless steel and either LaNi{sub 5{minus}x},Al{sub x}, or palladium supported on Kieselguhr granules (silica) during exposure in hydrogen was found in examination of retired prototype storage bed containers and special compatibility test samples. Intergranular surface ditching, observed on many of the stainless steel surfaces examined, was shown to result from air annealing and acid cleaning of stainless steel during normal fabrication. The ditched air annealed and acid cleaned stainless steel samples were more resistant to subsequent acid attack than vacuum annealed or polished samples without ditches.

  16. Effects of DC plasma nitriding parameters on microstructure and properties of 304L stainless steel

    SciTech Connect

    Wang Jun; Xiong Ji Peng Qian; Fan Hongyuan; Wang Ying; Li Guijiang; Shen Baoluo

    2009-03-15

    A wear-resistant nitrided layer was formed on a 304L austenitic stainless steel substrate by DC plasma nitriding. Effects of DC plasma nitriding parameters on the structural phases, micro-hardness and dry-sliding wear behavior of the nitrided layer were investigated by optical microscopy, X-ray diffraction, scanning electron microscopy, micro-hardness testing and ring-on-block wear testing. The results show that the highest surface hardness over a case depth of about 10 {mu}m is obtained after nitriding at 460 deg. C. XRD indicated a single expanded austenite phase and a single CrN nitride phase were formed at 350 deg. C and 480 deg. C, respectively. In addition, the S-phase layers formed on the samples provided the best dry-sliding wear resistance under the ring-on-block contact configuration test.

  17. Finite Element Modeling and Validation of Residual Stresses in 304 L Girth Welds

    SciTech Connect

    Dike, J.J.; Ortega, A.R.; Cadden, C.H.; Rangaswamy, P. Brown, D.

    1998-06-01

    Three dimensional finite element simulations of thermal and mechanical response of a 304 L stainless steel pipe subjected to a circumferential autogenous gas tungsten arc weld were used to predict residual stresses in the pipe. Energy is input into the thermal model using a volumetric heat source. Temperature histories from the thermal analysis are used as loads in the mechanical analyses. In the mechanical analyses, a state variable constitutive model was used to describe the material behavior. The model accounts for strain rate, temperature, and load path histories. The predicted stresses are compared with x-ray diffraction determinations of residual stress in the hoop and circumferential directions on the outside surface of the pipe. Calculated stress profiles fell within the measured data. Reasons for observed scatter in measured stresses are discussed.

  18. Material Corrosion and Plate-Out Test of Types 304L and 316L Stainless Steel

    SciTech Connect

    Zapp, P.E.

    2001-02-06

    Corrosion and plate-out tests were performed on 304L and 316L stainless steel in pretreated Envelope B and Envelope C solutions. Flat coupons of the two stainless steels were exposed to 100 degrees C liquid and to 74 degrees C and 88 degrees C vapor above the solutions for 61 days. No significant corrosion was observed either by weight-loss measurements or by microscopic examination. Most coupons had small weight gains due to plate-out of solids, which remained to some extent even after 24-hour immersion in 1 N nitric acid at room temperature. Plate-out was more significant in the Envelope B coupons, with film thickness from less than 0.001 in. to 0.003-inches.

  19. DIC-aided biaxial fatigue tests of a 304L steel

    NASA Astrophysics Data System (ADS)

    Poncelet, M.; Barbier, G.; Raka, B.; Courtin, S.; Desmorat, R.; Le-Roux, J. C.; Vincent, L.

    2010-06-01

    Several biaxial fatigue tests are conducted up to 106 cycles at room temperature in the context of a collaboration LMT-Cachan / EDF / AREVA / SNECMA / CEA. Malteses cross specimens of 304L steel, designed to initiate crack in the bulk, are loaded by a triaxial testing machine. A Digital Image Correlation technique is used to measure strain during loading and detect crack initiation early. A special optical assembly and a stroboscopic sampling method are set up in this purpose. Several types of loadings are performed: equibiaxial with a loading ratio R = 0.1, equibiaxial with loading ratio R = -1, pseudo uniaxial (cyclic loading at R= 0.1 in one direction and constant loading in the other). First results are commented.

  20. HYDROGEN EFFECTS ON STRAIN-INDUCED MARTENSITE FORMATION IN TYPE 304L STAINLESS STEEL

    SciTech Connect

    Morgan, M; Ps Lam, P

    2008-12-11

    Unstable austenitic stainless steels undergo a strain-induced martensite transformation. The effect of hydrogen on this transformation is not well understood. Some researchers believe that hydrogen makes the transformation to martensite more difficult because hydrogen is an austenite stabilizer. Others believe that hydrogen has little or no effect at all on the transformation and claim that the transformation is simply a function of strain and temperature. Still other researchers believe that hydrogen should increase the ability of the metal to transform due to hydrogen-enhanced dislocation mobility and slip planarity. While the role of hydrogen on the martensite transformation is still debated, it has been experimentally verified that this transformation does occur in hydrogen-charged materials. What is the effect of strain-induced martensite on hydrogen embrittlement? Martensite near crack-tips or other highly strained regions could provide much higher hydrogen diffusivity and allow for quicker hydrogen concentration. Martensite may be more intrinsically brittle than austenite and has been shown to be severely embrittled by hydrogen. However, it does not appear to be a necessary condition for embrittlement since Type 21-6-9 stainless steel is more stable than Type 304L stainless steel but susceptible to hydrogen embrittlement. In this study, the effect of hydrogen on strain-induced martensite formation in Type 304L stainless steel was investigated by monitoring the formation of martensite during tensile tests of as-received and hydrogen-charged samples and metallographically examining specimens from interrupted tensile tests after increasing levels of strain. The effect of hydrogen on the fracture mechanisms was also studied by examining the fracture features of as-received and hydrogen-charged specimens and relating them to the stress-strain behavior.

  1. Comparison of Strength and Serration at Cryogenic Temperatures among 304L, 316L and 310S Steels

    NASA Astrophysics Data System (ADS)

    Shibata, K.; Ogata, T.; Nyilas, A.; Yuri, T.; Fujii, H.; Ohmiya, S.; Onishi, T.; Weiss, K. P.

    2008-03-01

    Tensile tests of 310S steel were performed at temperatures below 300 K and the yield strength and deformation behavior were compared with those of 304L and 316L steels. Computer simulations were also carried out to graph stress-elongation curves in order to discuss the effects of martensitic transformations induced during deformation on their strengths and deformation behavior at low temperatures. Tensile tests showed that yield strength of 310S steel is highest and that of 304L is lowest. The differences in yield strengths between 316L and 310S steels and between 304L and 316L steels are larger than those expected from the differences in solid solution strengthening. This can be explained by the effect of the strain through γ to ɛ martensitic transformation induced by elastic stress in 304L and 316L steels. The strength level and the shape of stress-elongation curves at cryogenic temperatures excluding serration can be qualitatively revealed by simulation when higher strength of ɛ phase comparing to α' phase and the window effect of α' were considered simultaneously. In liquid hydrogen, the three steels exhibit large serrations on the stress-elongation curves after the deformation near to the ultimate stress, while the curves are smooth before the onset of the serration. Such serrations in liquid hydrogen could not be revealed by simulation.

  2. Microstructural origins of radiation-induced changes in mechanical properties of 316 L and 304 L austenitic stainless steels irradiated with mixed spectra of high-energy protons and spallation neutrons

    NASA Astrophysics Data System (ADS)

    Sencer, B. H.; Bond, G. M.; Hamilton, M. L.; Garner, F. A.; Maloy, S. A.; Sommer, W. F.

    2001-07-01

    A number of candidate alloys were exposed to a particle flux and spectrum at Los Alamos Neutron Science Center (LANSCE) that closely match the mixed high-energy proton/neutron spectra expected in accelerator production of tritium (APT) window and blanket applications. Austenitic stainless steels 316 L and 304 L are two of these candidate alloys possessing attractive strength and corrosion resistance for APT applications. This paper describes the dose dependence of the irradiation-induced microstructural evolution of SS 316 L and 304 L in the temperature range 30-60°C and consequent changes in mechanical properties. It was observed that the microstructural evolution during irradiation was essentially identical in the two alloys, a behavior mirrored in their changes in mechanical properties. With one expection, it was possible to correlate all changes in mechanical properties with visible microstructural features. A late-term second abrupt decrease in uniform elongation was not associated with visible microstructure, but is postulated to be a consequence of large levels of retained hydrogen measured in the specimens. In spite of large amounts of both helium and hydrogen retained, approaching 1 at.% at the highest exposures, no visible cavities were formed, indicating that the gas atoms were either in solution or in subresolvable clusters.

  3. Atmospheric pitting corrosion of 304L stainless steel: the role of highly concentrated chloride solutions.

    PubMed

    Street, Steven R; Mi, Na; Cook, Angus J M C; Mohammed-Ali, Haval B; Guo, Liya; Rayment, Trevor; Davenport, Alison J

    2015-01-01

    The morphology of atmospheric pitting corrosion in 304L stainless steel plate was analysed using MgCl(2) droplets in relation to changes in relative humidity (RH) and chloride deposition density (CDD). It was found that highly reproducible morphologies occur that are distinct at different RH. Pitting at higher concentrations, i.e. lower RH, resulted in satellite pits forming around the perimeter of wide shallow dish regions. At higher RH, these satellite pits did not form and instead spiral attack into the shallow region was observed. Increasing CDD at saturation resulted in a very broad-mouthed pitting attack within the shallow dish region. Large data sets were used to find trends in pit size and morphology in what is essentially a heterogeneous alloy. Electrochemical experiments on 304 stainless steel wires in highly saturated solutions showed that the passive current density increased significantly above 3 M MgCl(2) and the breakdown pitting potential dropped as the concentration increased. It is proposed that the shallow dish regions grow via enhanced dissolution of the passive film, whereas satellite pits and a spiral attack take place with active dissolution of bare metal surfaces. PMID:25910020

  4. Mechanisms-based viscoplasticity: Theoretical approach and experimental validation for steel 304L

    PubMed Central

    Zubelewicz, Aleksander; Oliferuk, Wiera

    2016-01-01

    We propose a mechanisms-based viscoplasticity approach for metals and alloys. First, we derive a stochastic model for thermally-activated motion of dislocations and, then, introduce power-law flow rules. The overall plastic deformation includes local plastic slip events taken with an appropriate weight assigned to each angle of the plane misorientation from the direction of maximum shear stress. As deformation progresses, the material experiences successive reorganizations of the slip systems. The microstructural evolution causes that a portion of energy expended on plastic deformation is dissipated and the rest is stored in the defect structures. We show that the reorganizations are stable in a homogeneously deformed material. The concept is tested for steel 304L, where we reproduce experimentally obtained stress-strain responses, we construct the Frost-Ashby deformation map and predict the rate of the energy storage. The storage is assessed in terms of synchronized measurements of temperature and displacement distributions on the specimen surface during tensile loading. PMID:27026209

  5. Deep drawing of 304 L Steel Sheet using Vegetable oils as Forming Lubricants

    NASA Astrophysics Data System (ADS)

    Shashidhara, Y. M.; Jayaram, S. R.

    2012-12-01

    The study involves the evaluation of deep drawing process using two non edible oils, Pongam (Pongammia pinnata) and Jatropha (Jatropha carcass) as metal forming lubricants. Experiments are conducted on 304L steel sheets under the raw and modified oils with suitable punch and die on a hydraulic press of 200 ton capacity. The punch load, draw-in-length and wall thickness distribution for deep drawn cups are observed. The drawn cups are scanned using laser scanning technique and 3D models are generated using modeling package. The wall thickness profiles of cups at different sections (or height) are measured using CAD package. Among the two raw oils, the drawn cups under Jatropha oil, have uniform wall thickness profile compared to Pongam oil. Uneven flow of material and cup rupturing is observed under methyl esters of Pongam and Jatropha oil lubricated conditions. However, the results are observed under epoxidised Jatropha oil with uniform metal flow and wall thicknesses compared to mineral and other versions of vegetable oils.

  6. Mechanisms-based viscoplasticity: Theoretical approach and experimental validation for steel 304L.

    PubMed

    Zubelewicz, Aleksander; Oliferuk, Wiera

    2016-01-01

    We propose a mechanisms-based viscoplasticity approach for metals and alloys. First, we derive a stochastic model for thermally-activated motion of dislocations and, then, introduce power-law flow rules. The overall plastic deformation includes local plastic slip events taken with an appropriate weight assigned to each angle of the plane misorientation from the direction of maximum shear stress. As deformation progresses, the material experiences successive reorganizations of the slip systems. The microstructural evolution causes that a portion of energy expended on plastic deformation is dissipated and the rest is stored in the defect structures. We show that the reorganizations are stable in a homogeneously deformed material. The concept is tested for steel 304L, where we reproduce experimentally obtained stress-strain responses, we construct the Frost-Ashby deformation map and predict the rate of the energy storage. The storage is assessed in terms of synchronized measurements of temperature and displacement distributions on the specimen surface during tensile loading. PMID:27026209

  7. Investigation of high temperature corrosion behavior on 304L austenite stainless steel in corrosive environments

    SciTech Connect

    Sahri, M. I.; Othman, N. K.; Samsu, Z.; Daud, A. R.

    2014-09-03

    In this work, 304L stainless steel samples were exposed at 700 °C for 10hrs in different corrosive environments; dry oxygen, molten salt, and molten salt + dry oxygen. The corrosion behavior of samples was analyzed using weight change measurement technique, optical microscope (OM) and Scanning Electron Microscope (SEM) equipped with Energy Dispersive X-ray (EDX). The existence phases of corroded sample were determined using X-ray Diffraction (XRD). The lowest corrosion rate was recorded in dry oxygen while the highest was in molten salt + dry oxygen environments with the value of 0.0062 mg/cm{sup 2} and −13.5225 mg/cm{sup 2} respectively. The surface morphology of sample in presence of salt mixture showed scale spallation. Oxide scales of Fe{sub 3}O{sub 4}, Fe{sub 2}O{sub 3} were the main phases developed and detected by XRD technique. Cr{sub 2}O{sub 3} was not developed in every sample as protective layers but chromate-rich oxide was developed. The cross-section analysis found the oxide scales were in porous, thick and non-adherent that would not an effective barrier to prevent from further degradation of alloy. EDX analysis also showed the Cr-element was low compared to Fe-element at the oxide scale region.

  8. HYDROGEN EFFECTS ON THE BURST PROPERTIES OF TYPE 304L STAINLESS STEEL FLAWED VESSELS

    SciTech Connect

    Morgan, M; Monica Hall, M; Ps Lam, P; Dean Thompson, D

    2008-03-27

    The effect of hydrogen on the burst properties Type 304L stainless steel vessels was investigated. The purpose of the study was to compare the burst properties of hydrogen-exposed stainless steel vessels burst with different media: water, helium gas, or deuterium gas. A second purpose of the tests was to provide data for the development of a predictive finite-element model. The burst tests were conducted on hydrogen-exposed and unexposed axially-flawed cylindrical vessels. The results indicate that samples burst pneumatically had lower volume ductility than those tested hydraulically. Deuterium gas tests had slightly lower ductility than helium gas tests. Burst pressures were not affected by burst media. Hydrogen-charged samples had lower volume ductility and slightly higher burst pressures than uncharged samples. Samples burst with deuterium gas fractured by quasi-cleavage near the inside wall. The results of the tests were used to improve a previously developed predictive finite-element model. The results show that predicting burst behavior requires as a material input the effect of hydrogen on the plastic strain to fracture from tensile tests. The burst test model shows that a reduction in the plastic strain to fracture of the material will result in lower volume ductility without a reduction in burst pressure which is in agreement with the burst results.

  9. Mechanisms-based viscoplasticity: Theoretical approach and experimental validation for steel 304L

    NASA Astrophysics Data System (ADS)

    Zubelewicz, Aleksander; Oliferuk, Wiera

    2016-03-01

    We propose a mechanisms-based viscoplasticity approach for metals and alloys. First, we derive a stochastic model for thermally-activated motion of dislocations and, then, introduce power-law flow rules. The overall plastic deformation includes local plastic slip events taken with an appropriate weight assigned to each angle of the plane misorientation from the direction of maximum shear stress. As deformation progresses, the material experiences successive reorganizations of the slip systems. The microstructural evolution causes that a portion of energy expended on plastic deformation is dissipated and the rest is stored in the defect structures. We show that the reorganizations are stable in a homogeneously deformed material. The concept is tested for steel 304L, where we reproduce experimentally obtained stress-strain responses, we construct the Frost-Ashby deformation map and predict the rate of the energy storage. The storage is assessed in terms of synchronized measurements of temperature and displacement distributions on the specimen surface during tensile loading.

  10. Auger electron spectroscopy study of alloy 718 and 304L stainless steel irradiated with 800 MeV protons

    NASA Astrophysics Data System (ADS)

    García-Mazarío, M.; Hernández-Mayoral, M.; Lancha, A. M.

    2001-07-01

    It is well known that radiation produces changes in materials microstructure such as formation of defects, dissolution and redistribution of secondary phases, precipitation of new phases, etc. and changes in the grain boundary microchemistry by a process known as radiation-induced segregation (RIS). This paper describes the grain boundary microchemical characterization of alloy 718 and 304L stainless steel irradiated with high-energy protons at Los Alamos Neutron Science Center (LANSCE), performed by means of Auger electron spectroscopy (AES). In addition, non-irradiated alloy 718 was characterized as reference. The Auger results showed that as a consequence of exposure to proton radiation, the changes observed in alloy 718 were the disappearance of the nickel and niobium rich grain boundaries precipitates and RIS of the major alloying elements (nickel to grain boundaries, and chromium and iron away from grain boundaries). On the other hand, in irradiated AISI 304L no differences were observed between intergranular and transgranular areas.

  11. Notch Effect on Tensile Deformation Behavior of 304L and 316L Steels in Liquid Helium and Hydrogen

    NASA Astrophysics Data System (ADS)

    Shibata, K.; Fujii, H.

    2004-06-01

    Tensile tests of type 304L and 316L steels were carried out using round bar specimens with a notch in liquid helium, hydrogen, liquid nitrogen and at ambient temperature. The obtained tensile strengths were compared with the tensile strengths of smooth specimens. For smooth specimens, tensile strength increased with a decrease in temperature and the strengths in liquid helium and hydrogen show similar values in both steels. For notched specimen of 304L steel, tensile strength (including fracture strength) increased noticeably from ambient to liquid nitrogen temperature but showed a large decrease in liquid helium and hydrogen. In liquid hydrogen and helium, the tensile strength is a little lower in liquid hydrogen than in liquid helium and both strengths are lower than tensile strengths of smooth specimens. For notched specimen of 316L steel, an increase in tensile strength from ambient to liquid nitrogen temperature was not so large and a decrease from liquid nitrogen to liquid hydrogen was small. The tensile strengths in liquid helium and hydrogen were nearly same and higher than those of smooth specimens. Different behavior of serration was observed between liquid helium and hydrogen, and between 304L and 316L steels. The reasons for these differences were discussed using computer simulation.

  12. Notch Effect on Tensile Deformation Behavior of 304L and 316L Steels in Liquid Helium and Hydrogen

    SciTech Connect

    Shibata, K.; Fujii, H.

    2004-06-28

    Tensile tests of type 304L and 316L steels were carried out using round bar specimens with a notch in liquid helium, hydrogen, liquid nitrogen and at ambient temperature. The obtained tensile strengths were compared with the tensile strengths of smooth specimens. For smooth specimens, tensile strength increased with a decrease in temperature and the strengths in liquid helium and hydrogen show similar values in both steels. For notched specimen of 304L steel, tensile strength (including fracture strength) increased noticeably from ambient to liquid nitrogen temperature but showed a large decrease in liquid helium and hydrogen. In liquid hydrogen and helium, the tensile strength is a little lower in liquid hydrogen than in liquid helium and both strengths are lower than tensile strengths of smooth specimens. For notched specimen of 316L steel, an increase in tensile strength from ambient to liquid nitrogen temperature was not so large and a decrease from liquid nitrogen to liquid hydrogen was small. The tensile strengths in liquid helium and hydrogen were nearly same and higher than those of smooth specimens. Different behavior of serration was observed between liquid helium and hydrogen, and between 304L and 316L steels. The reasons for these differences were discussed using computer simulation.

  13. Irradiation creep of SA 304L and CW 316 stainless steels: Mechanical behaviour and microstructural aspects. Part I: Experimental results

    NASA Astrophysics Data System (ADS)

    Garnier, J.; Bréchet, Y.; Delnondedieu, M.; Pokor, C.; Dubuisson, P.; Renault, A.; Averty, X.; Massoud, J. P.

    2011-06-01

    Solution annealed 304L (SA 304L) and cold work 316 (CW 316) austenitic stainless steel irradiation creep behaviour have been studied thoroughly. Irradiations were carried out in fast breeder reactors BOR-60 (at 330 °C, up to 120 dpa) and EBR-II (at 375 °C, up to 10.5 dpa), and in the OSIRIS mixed spectrum reactor (at 330 °C, up to 9.8 dpa). After an incubation threshold, the irradiation creep of the austenitic stainless steels is linear in stress and in dose. Creep appears to be athermal in this temperature range. A significant difference in the behaviour is measured between the creep of SA 304L and CW 316. In order to study the anisotropy of loop population, which would be the signature of a possible stress induced preferential absorption (SIPA) mechanism for irradiation creep, special attention was given to the measurement of anisotropy of loop distribution between the four families. The anisotropy induced by an applied stress has been shown to be in the range of the statistical scatter in the situation where no stress is applied. TEM microstructural analyses performed on this sample show slight difference between the microstructure of specimens deformed under irradiation and the microstructure of specimens irradiated without stress under the same irradiation conditions.

  14. Microstructural Study Of Fusion Welds in 304L and 21Cr-6Ni-9Mn Stainless Steels (U)

    SciTech Connect

    MICHAEL, TOSTEN

    2005-03-01

    Light-optical and transmission electron microscopy (TEM) have been employed to characterize the microstructures of a series of fusion welds made on 304L and 21-6-9 stainless steels. The materials investigated in this study included high-energy-rate-forged 304L, conventionally forged 21-6-9, and 304L weld critical plate (higher ferrite potential). The weld critical plate contained an electron beam weld (no filler wire) while other specimens were welded with various combinations of 308L, 309L modified (MOD) and 312 MOD stainless steel filler wires to produce samples with a range of delta ferrite contents (4 to 33 percent) in the resulting welds. TEM specimens were prepared from broken arc-shaped, mechanical property test specimens that had been used to measure fracture toughness of the fusion welds. Specimens were prepared from regions of the weld heat-affected zones as well as from areas within the weld metal, including areas close to the fracture surface (plastically deformed regions). The observed microstructures varied according to the amount of ferrite in each weld. At the lowest ferrite levels the microstructure consisted of austenite and skeletal ferrite with austenite being the majority (matrix) phase. At intermediate levels of ferrite, lathy austenite/ferrite was observed and the ferrite became continuous throughout the specimens examined. In the weld with the most ferrite, many austenite morphologies were observed and ferrite was the matrix phase. Closest to the fracture surface an increase in dislocation density in both the ferrite and austenite were observed in all welds. Deformation twinning was also observed in the austenite. Many of the welds contained a large number of non-metallic inclusions (oxide particles) which most likely originated from impurities in the weld wires.

  15. Effects of Low Temperature on Hydrogen-Assisted Crack Growth in Forged 304L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Jackson, Heather; San Marchi, Chris; Balch, Dorian; Somerday, Brian; Michael, Joseph

    2016-08-01

    The objective of this study was to evaluate effects of low temperature on hydrogen-assisted crack propagation in forged 304L austenitic stainless steel. Fracture initiation toughness and crack-growth resistance curves were measured using fracture mechanics specimens that were thermally precharged with 140 wppm hydrogen and tested at 293 K or 223 K (20 °C or -50 °C). Fracture initiation toughness for hydrogen-precharged forgings decreased by at least 50 to 80 pct relative to non-charged forgings. With hydrogen, low-temperature fracture initiation toughness decreased by 35 to 50 pct relative to room-temperature toughness. Crack growth without hydrogen at both temperatures was microstructure-independent and indistinguishable from blunting, while with hydrogen microcracks formed by growth and coalescence of microvoids. Initiation of microvoids in the presence of hydrogen occurred where localized deformation bands intersected grain boundaries and other deformation bands. Low temperature additionally promoted fracture initiation at annealing twin boundaries in the presence of hydrogen, which competed with deformation band intersections and grain boundaries as sites of microvoid formation and fracture initiation. A common ingredient for fracture initiation was stress concentration that arose from the intersection of deformation bands with these microstructural obstacles. The localized deformation responsible for producing stress concentrations at obstacles was intensified by low temperature and hydrogen. Crack orientation and forging strength were found to have a minor effect on fracture initiation toughness of hydrogen-supersaturated 304L forgings.

  16. The fatigue crack initiation at the interface between matrix and {delta}-ferrite in 304L stainless steel

    SciTech Connect

    Rho, B.S.; Hong, H.U.; Nam, S.W.

    1998-10-13

    It is well known that austenitic stainless steels have good mechanical properties and good corrosion resistance at high temperatures and are widely used in high temperature application. However, representative 304L stainless steel among austenitic stainless steels has the undesirable {delta}-ferrite in {gamma} matrix unavoidably because of the limitation of the manufacturing process. While large amounts of {delta}-ferrite in the austenitic stainless steels can give rise to a decrease in the hot workability, the absence of {delta}-ferrite in 304L stainless steel can be the cause of longitudinal facial crack and shortness of continuous cast slab. However, there are few reported papers related with the effect of {delta}-ferrite nucleating the initial crack at the interface between matrix and {delta}-ferrite on fatigue properties at high temperature. In the present work, a comparison of fatigue life with the amount of {delta}-ferrite was examined and to find out the mechanism of crack initiation caused by {delta}-ferrite, dislocation behavior near the interface between {delta}-ferrite and matrix during fatigue testing was analyzed. To analyze the dislocation character near the interface between the matrix and {delta}-ferrite during a low cycle fatigue test, trace analysis was applied. Using Burgers vector and dislocation line direction, calculated by trace analysis, it was possible to obtain some characteristic of dislocation behaviors near the interface.

  17. Corrosion of high Ni-Cr alloys and Type 304L stainless steel in HNO/sub 3/-HF

    SciTech Connect

    Ondrejcin, R.S.; McLaughlin, B.D.

    1980-04-01

    Nineteen alloys were evaluated as possible materials of construction for steam heating coils, the dissolver vessel, and the off-gas system of proposed facilities to process thorium and uranium fuels. Commercially available alloys were found that are satisfactory for all applications. With thorium fuel, which requires HNO/sub 3/-HF for dissolution, the best alloy for service at 130/sup 0/C when complexing agents for fluoride are used is Inconel 690; with no complexing agents at 130/sup 0/C, Inconel 671 is best. At 95/sup 0/C, six other alloys tested would be adequate: Haynes 25, Ferralium, Inconel 625, Type 304L stainless steel, Incoloy 825, and Haynes 20 (in order of decreasing preference); based on composition, six untested alloys would also be adequate. The ions most effective in reducing fluoride corrosion were the complexing agents Zr/sup 4 +/ and Th/sup 4 +/; Al/sup 3 +/ was less effective. With uranium fuel, modestly priced Type 304L stainless steel is adequate. Corrosion will be most severe in HNO/sub 3/-HF used occasionally for flushing and in solutions of HNO/sub 3/ and corrosion products (ferric and dichromate ions). HF corrosion can be minimized by complexing the fluoride ion and by passivation of the steel with strong nitric acid. Corrosion caused by corrosion products can be minimized by operating at lower temperatures.

  18. Environmental resistance of oxide tags fabricated on 304L stainless steel via nanosecond pulsed laser irradiation

    SciTech Connect

    Lawrence, Samantha Kay; Adams, David P.; Bahr, David F.; Moody, Neville R.

    2015-11-14

    Nanosecond pulsed laser irradiation was used to fabricate colored, mechanically robust oxide “tags” on 304L stainless steel. Immersion in simulated seawater solution, salt fog exposure, and anodic polarization in a 3.5% NaCl solution were employed to evaluate the environmental resistance of these oxide tags. Single layer oxides outside a narrow thickness range (~ 100–150 nm) are susceptible to dissolution in chloride containing environments. The 304L substrates immediately beneath the oxides corrode severely—attributed to Cr-depletion in the melt zone during laser processing. For the first time, multilayered oxides were fabricated with pulsed laser irradiation in an effort to expand the protective thickness range while also increasing the variety of film colors attainable in this range. Layered films grown using a laser scan rate of 475 mm/s are more resistant to both localized and general corrosion than oxides fabricated at 550 mm/s. Furthermore, in the absence of pre-processing to mitigate Cr-depletion, layered films can enhance environmental stability of the system.

  19. Effects of Low Temperature on Hydrogen-Assisted Crack Growth in Forged 304L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Jackson, Heather; San Marchi, Chris; Balch, Dorian; Somerday, Brian; Michael, Joseph

    2016-06-01

    The objective of this study was to evaluate effects of low temperature on hydrogen-assisted crack propagation in forged 304L austenitic stainless steel. Fracture initiation toughness and crack-growth resistance curves were measured using fracture mechanics specimens that were thermally precharged with 140 wppm hydrogen and tested at 293 K or 223 K (20 °C or -50 °C). Fracture initiation toughness for hydrogen-precharged forgings decreased by at least 50 to 80 pct relative to non-charged forgings. With hydrogen, low-temperature fracture initiation toughness decreased by 35 to 50 pct relative to room-temperature toughness. Crack growth without hydrogen at both temperatures was microstructure-independent and indistinguishable from blunting, while with hydrogen microcracks formed by growth and coalescence of microvoids. Initiation of microvoids in the presence of hydrogen occurred where localized deformation bands intersected grain boundaries and other deformation bands. Low temperature additionally promoted fracture initiation at annealing twin boundaries in the presence of hydrogen, which competed with deformation band intersections and grain boundaries as sites of microvoid formation and fracture initiation. A common ingredient for fracture initiation was stress concentration that arose from the intersection of deformation bands with these microstructural obstacles. The localized deformation responsible for producing stress concentrations at obstacles was intensified by low temperature and hydrogen. Crack orientation and forging strength were found to have a minor effect on fracture initiation toughness of hydrogen-supersaturated 304L forgings.

  20. Tensile Stress-Strain Results for 304L and 316L Stainless-Steel Plate at Temperature

    SciTech Connect

    R. K. Blandford; D. K. Morton; S. D. Snow; T. E. Rahl

    2007-07-01

    The Idaho National Laboratory (INL) is conducting moderate strain rate (10 to 200 per second) research on stainless steel materials in support of the Department of Energy’s (DOE) National Spent Nuclear Fuel Program (NSNFP). For this research, strain rate effects are characterized by comparison to quasi-static tensile test results. Considerable tensile testing has been conducted resulting in the generation of a large amount of basic material data expressed as engineering and true stress-strain curves. The purpose of this paper is to present the results of quasi-static tensile testing of 304/304L and 316/316L stainless steels in order to add to the existing data pool for these materials and make the data more readily available to other researchers, engineers, and interested parties. Standard tensile testing of round specimens in accordance with ASTM procedure A 370-03a were conducted on 304L and 316L stainless-steel plate materials at temperatures ranging from -20 °F to 600 °F. Two plate thicknesses, eight material heats, and both base and weld metal were tested. Material yield strength, Young’s modulus, ultimate strength, ultimate strain, failure strength and failure strain were determined, engineering and true stress-strain curves to failure were developed, and comparisons to ASME Code minimums were made. The procedures used during testing and the typical results obtained are described in this paper.

  1. Surface decontamination of Type 304L stainless steel with electrolytically generated hydrogen: Design and operation of the electrolyzer

    SciTech Connect

    Bellanger, G. )

    1993-11-01

    The surface of tritiated Type 304L stainless steel is decontaminated by isotopic exchange with the hydrogen generated in an electrolyzer. This steel had previously been exposed to tritium in a tritium gas facility for several years. The electrolyzer for the decontamination uses a conducting solid polymer electrolyte made of a Nafion membrane. The cathode where the hydrogen is formed is nickel deposited on one of the polymer surfaces. This cathode is placed next to the region of the steel to be decontaminated. The decontamination involves, essentially, the tritiated oxide layers of which the initial radioactivity is [approximately] 5 kBq/cm[sup 2]. After treatment for 1 h, the decontamination factor is 8. 9 refs., 16 figs., 2 tabs.

  2. The effects of surface pretreatment and nitrogen tetroxide purification on the corrosion rate of Type 304L stainless steel

    NASA Technical Reports Server (NTRS)

    Blue, G. D.; Moran, C. M.

    1985-01-01

    Corrosion rates of 304L stainless steel coupons in MON-1 oxidizer have been measured as a function of cleaning procedures employed, surface layer positions, propellant impurity levels, and short-term exposure durations (14 to 90 days). Of special interest was propellant contamination by buildup of soluble iron, which may cause flow decay. Surface treatments employed were combinations of cleaning, pickling, and passivation procedures. Propellants used were MIL-SPEC MON-1 and several types of purified NTO (i.e., low water, low chloride) which may, at a later time, be specified as spacecraft grade. Pretest coupon surface analysis by X-ray photoelectron spectroscopy (XPS-ESCA) has revealed important differences, for the different cleaning procedures, in the make-up of the surface layer, both in composition and state of chemical combination of the elements involved. Comparisons will be made of XPS/ESCA data, for different cleaning procedures, for specimens before and after propellant exposure.

  3. Result of International Round Robin Test on Young's Modulus Measurement of 304L and 316L Steels at Cryogenic Temperatures

    SciTech Connect

    Shibata, K.; Ogata, T.; Nyilas, A.; Walsh, R. P.; Toplosky, V. J.; Millet, M. F.; Shindo, Y.; Fujii, H.; Ohmiya, S.; Ishio, K.; Nakajima, H.; Takano, K.; Mitterbacher, H.; Gigante, P.

    2006-03-31

    Ogata et al. reported in 1996 results of international Round Robin tests on mechanical property measurement of several metals at cryogenic temperatures. Following the report, the standard deviation of Young's modulus of 316L steel is much larger than those of yield and tensile strengths, that is, 4.6 % of the mean value for Young's modulus, while 1.4 % and 1.6 % of the mean values for yield and for tensile strengths, respectively. Therefore, an international Round Robin test on Young's modulus of two austenitic stainless steels at cryogenic temperatures under the participation often institutes from four nations has been initiated within these two years. As a result, the ratios of standard deviation to the mean values are 4.2 % for 304L and 3.6 % for 316L. Such a drop in the standard deviation is attributable to the decrease in the number of institute owing to the application of single extensometer or direct strain gage technique.

  4. Nanosecond laser surface modification of AISI 304L stainless steel: Influence the beam overlap on pitting corrosion resistance

    NASA Astrophysics Data System (ADS)

    Pacquentin, Wilfried; Caron, Nadège; Oltra, Roland

    2014-01-01

    Surface modifications of AISI 304L stainless steel by laser surface melting (LSM) were investigated using a nanosecond pulsed laser-fibre doped by ytterbium at different overlaps. The objective was to study the change in the corrosion properties induced by the treatment of the outer-surface of the stainless steel without modification of the bulk material. Different analytical techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and glow discharge optical emission spectrometry (GDOES) were used to characterize the laser-melted surface. The corrosion resistance was evaluated in a chloride solution at room temperature by electrochemical tests. The results showed that the crystallographic structure, the chemical composition, the properties of the induced oxide layer and consequently the pitting corrosion resistance strongly depend on the overlap rate. The most efficient laser parameters led to an increase of the pitting potential by more than 300 mV, corresponding to a quite important improvement of the corrosion resistance. This latter was correlated to chromium enrichment (47 wt.%) at the surface of the stainless steel and the induced absence of martensite and ferrite phases. However, these structural and chemical modifications were not sufficient to explain the change in corrosion behaviour: defects and adhesion of the surface oxide layer must have been taken into consideration.

  5. Microstructure and Mechanical Properties of Plasma Arc Brazed AISI 304L Stainless Steel and Galvanized Steel Plates

    NASA Astrophysics Data System (ADS)

    Jin, Yajuan; Li, Ruifeng; Yu, Zhishui; Wang, Yu

    2016-04-01

    Plasma arc brazing is used to join the AISI 304L stainless steel and galvanized steel plate butt joints with the CuSi3Mn1 filler wire. The effect of parameters on weld surface appearance, interfacial microstructure, and composition distribution in the joint was studied. The microhardness and mechanical tests were conducted to determine the mechanical properties of the welded specimens. The results indicated that good appearance, bead shape, and sufficient metallurgical bonding could be obtained when the brazing process was performed with a wire feeding speed of 0.8 m/min, plasma gas flow rate of 3.0 l/min, welding current of 100 A, and welding speed of 27 cm/min. During plasma arc brazing process, the top corner of the stainless steel and galvanized steel plate were heated and melted, and the melted quantity of stainless steel was much more than that of the galvanized steel due to the thermal conductivity coefficient difference between the dissimilar materials. The microhardness test results shows that the microhardness value gradually increased from the side of the galvanized steel to the stainless steel in the joint, and it is good for improving the mechanical properties of joint. The tensile strength was a little higher than that of the brazing filler, and the fracture position of weld joint was at the base metal of galvanized steel plate.

  6. Evaluation of stress corrosion cracking of irradiated 304L stainless steel in PWR environment using heavy ion irradiation

    NASA Astrophysics Data System (ADS)

    Gupta, J.; Hure, J.; Tanguy, B.; Laffont, L.; Lafont, M.-C.; Andrieu, E.

    2016-08-01

    IASCC has been a major concern regarding the structural and functional integrity of core internals of PWR's, especially baffle-to-former bolts. Despite numerous studies over the past few decades, additional evaluation of the parameters influencing IASCC is still needed for an accurate understanding and modeling of this phenomenon. In this study, Fe irradiation at 450 °C was used to study the cracking susceptibility of 304 L austenitic stainless steel. After 10 MeV Fe irradiation to 5 dpa, irradiation-induced damage in the microstructure was characterized and quantified along with nano-hardness measurements. After 4% plastic strain in a PWR environment, quantitative information on the degree of strain localization, as determined by slip-line spacing, was obtained using SEM. Fe-irradiated material strained to 4% in a PWR environment exhibited crack initiation sites that were similar to those that occur in neutron- and proton-irradiated materials, which suggests that Fe irradiation may be a representative means for studying IASCC susceptibility. Fe-irradiated material subjected to 4% plastic strain in an inert argon environment did not exhibit any cracking, which suggests that localized deformation is not in itself sufficient for initiating cracking for the irradiation conditions used in this study.

  7. Numerical Simulation and Artificial Neural Network Modeling for Predicting Welding-Induced Distortion in Butt-Welded 304L Stainless Steel Plates

    NASA Astrophysics Data System (ADS)

    Narayanareddy, V. V.; Chandrasekhar, N.; Vasudevan, M.; Muthukumaran, S.; Vasantharaja, P.

    2016-02-01

    In the present study, artificial neural network modeling has been employed for predicting welding-induced angular distortions in autogenous butt-welded 304L stainless steel plates. The input data for the neural network have been obtained from a series of three-dimensional finite element simulations of TIG welding for a wide range of plate dimensions. Thermo-elasto-plastic analysis was carried out for 304L stainless steel plates during autogenous TIG welding employing double ellipsoidal heat source. The simulated thermal cycles were validated by measuring thermal cycles using thermocouples at predetermined positions, and the simulated distortion values were validated by measuring distortion using vertical height gauge for three cases. There was a good agreement between the model predictions and the measured values. Then, a multilayer feed-forward back propagation neural network has been developed using the numerically simulated data. Artificial neural network model developed in the present study predicted the angular distortion accurately.

  8. Solidification Behavior and Weldability of Dissimilar Welds Between a Cr-Free, Ni-Cu Welding Consumable and Type 304L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Sowards, Jeffrey W.; Liang, Dong; Alexandrov, Boian T.; Frankel, Gerald S.; Lippold, John C.

    2012-04-01

    The solidification behavior of a Cr-free welding consumable based on the Ni-Cu system was evaluated in conjunction with Type 304L stainless steel. The weld metal microstructure evolution was evaluated with optical and secondary electron microscopy, energy dispersive spectroscopy, X-ray diffraction, button melting, and thermodynamic (CALPHAD-based) modeling. Solidification partitioning patterns showed that higher dilutions of the filler metal by Type 304L increased segregation of Ti, Cu, and Si to interdendritic regions. Button melting experiments showed a widening of the solidification temperature range with increasing dilution because of the expansion of the austenite solidification range and formation of Ti(C,N) via a eutectic reaction. The model predictions showed good correlation with button melting experiments and were used to evaluate the nature of the Ti(C,N) precipitation reaction. Solidification cracking susceptibility of the weld metal was shown to increase with dilution of 304L stainless steel based on testing conducted with the cast pin tear test. The increase in cracking susceptibility is associated with expansion of the solidification temperature range and the presence of eutectic liquid at the end of solidification that wets solidification grain boundaries.

  9. RESULTS OF EXPERIMENT TO DETERMINE CORROSION RATES FOR 304L IN HB-LINE DISSOLVER VESSEL VENTILATION SYSTEM

    SciTech Connect

    Mickalonis, J; Kathryn Counts, K

    2008-02-22

    Radioactive material being processed as part of the DE3013 program for HB-Line will result in the presence of chlorides, and in some cases fluorides, in the dissolver. Material Science and Technology developed an experimental plan to evaluate the impact of chloride on corrosion of the dissolver vessel ventilation system. The plan set test variables from the proposed operating parameters, previous test results, and a desired maximum chloride concentration for processing. The test variables included concentrations of nitric acid, fluorides and chlorides, and the presence of a welded and stressed metal coupon. Table 1 contains expected general corrosion rates in the HB-Line vessel vent system from dissolution of 3013 contents of varying nitric acid and chloride content. These general corrosion rates were measured upstream of the condenser in the experiment's offgas system near the entrance to the dissolver. However, they could apply elsewhere in the offgas system, depending on factors not simulated in the testing, including offgas system temperatures and airflow. Localized corrosion was significant in Tests One, Two, and Three. This corrosion is significant because it will probably be the first mode of penetration of the 304L steel in several places in the system. See Table 2. For Tests One and Three, the penetration rate of localized corrosion was much higher than that for general corrosion. It was approximately four times higher in Test One and at least 45 times higher in Test Three, penetrating an entire coupon thickness of 54 mils in 186 hours or less. There was no significant difference in corrosion between welded areas and un-welded areas on coupons. There was also no significant attack on stressed portions of coupons. It is probable that the lack of corrosion was because the stressed areas were facing downwards and offered no place for condensation or deposits to form. Had deposits formed, pitting may have occurred and led to stress corrosion cracking. The

  10. Laser surface melting and alloying of type 304L stainless steel: Improvement of corrosion and wear properties. Final report

    SciTech Connect

    Inal, O.T.

    1994-08-01

    Laser surface melting (LSM) of type 304L stainless steel and laser surface alloying (LSA) of this stainless steel with Mo and Ta have been studied to determine if corrosion and wear resistance properties can be improved. It was observed that these properties were affected by the presence of {delta}-ferrite, produced by the high cooling rate associated with LSM, as well as by compositional modifications in Mo-and Ta-alloyed layers. The {delta}-ferrite content was calculated from X-ray diffraction data to be 4.3 vol%, 77 vol% and 76 vol% for LSM, Mo-alloyed and Ta-alloyed LSA layers, respectively. Laser processing caused a lowered Mn content, by about 15%, and introduced extensive Mn-Si precipitation in the microstructure. In the LSM layer, the hardness increase was observed to be 10% due to refinement in subgrain structure. There was no martensitic transformation in the melted layer. {delta}-ferrite content was found to increase from 4.3 vol% at the surface to 9.9 vol% at the fusion line due to different cooling rates present in the melted layer. Passivation and pitting properties were seen to be enhanced with increase in {delta}-ferrite content in LSM samples. This is attributed to a primary solidification mode of {delta}-ferrite which dissolves more impurity elements, such as S, than austenite, as well as the removal and/or redistribution of inclusions in the melted layer. The stress corrosion cracking resistance of the melted layer was observed to be lowered; this is possibly because of the detriment to mechanical properties introduced by laser melting in the form of lowered ductility. The Mo-alloyed layer exhibited 50% increase in hardness, compared with the substrate, due to higher {delta}-ferrite content. It spontaneously passivated in 1N H{sub 2}SO{sub 4} solution, and there was no pit formation in 3.5 wt% NaCl and 10% FeCl{sub 3}{center_dot}6H{sub 2}O solutions.

  11. Effect of heat input on the microstructure, residual stresses and corrosion resistance of 304L austenitic stainless steel weldments

    SciTech Connect

    Unnikrishnan, Rahul; Idury, K.S.N. Satish; Ismail, T.P.; Bhadauria, Alok; Shekhawat, S.K.; Khatirkar, Rajesh K.; Sapate, Sanjay G.

    2014-07-01

    Austenitic stainless steels are widely used in high performance pressure vessels, nuclear, chemical, process and medical industry due to their very good corrosion resistance and superior mechanical properties. However, austenitic stainless steels are prone to sensitization when subjected to higher temperatures (673 K to 1173 K) during the manufacturing process (e.g. welding) and/or certain applications (e.g. pressure vessels). During sensitization, chromium in the matrix precipitates out as carbides and intermetallic compounds (sigma, chi and Laves phases) decreasing the corrosion resistance and mechanical properties. In the present investigation, 304L austenitic stainless steel was subjected to different heat inputs by shielded metal arc welding process using a standard 308L electrode. The microstructural developments were characterized by using optical microscopy and electron backscattered diffraction, while the residual stresses were measured by X-ray diffraction using the sin{sup 2}ψ method. It was observed that even at the highest heat input, shielded metal arc welding process does not result in significant precipitation of carbides or intermetallic phases. The ferrite content and grain size increased with increase in heat input. The grain size variation in the fusion zone/heat affected zone was not effectively captured by optical microscopy. This study shows that electron backscattered diffraction is necessary to bring out changes in the grain size quantitatively in the fusion zone/heat affected zone as it can consider twin boundaries as a part of grain in the calculation of grain size. The residual stresses were compressive in nature for the lowest heat input, while they were tensile at the highest heat input near the weld bead. The significant feature of the welded region and the base metal was the presence of a very strong texture. The texture in the heat affected zone was almost random. - Highlights: • Effect of heat input on microstructure, residual

  12. Investigation of micro-structure and micro-hardness properties of 304L stainless steel treated in a hot cathode arc discharge plasma

    SciTech Connect

    Malik, Hitendra K.; Singh, Omveer; Dahiya, Raj P.

    2015-08-28

    We have established a hot cathode arc discharge plasma system, where different stainless steel samples can be treated by monitoring the plasma parameters and nitriding parameters independently. In the present work, a mixture of 70% N{sub 2} and 30% H{sub 2} gases was fed into the plasma chamber and the treatment time and substrate temperature were optimized for treating 304L Stainless Steel samples. Various physical techniques such as x-ray diffraction, energy dispersive x-ray spectroscopy and micro-vickers hardness tester were employed to determine the structural, surface composition and surface hardness of the treated samples.

  13. Influence of microstructure on the corrosion resistance of AISI type 304L and type 316L sintered stainless steels exposed to ferric chloride solution

    SciTech Connect

    Otero, E.; Pardo, A.; Utrilla, M.V.; Perez, F.J.; Saenz, E.

    1995-10-01

    The corrosion behavior of type 304L and type 316L austenitic stainless steels, produced by powder metallurgy, when exposed to a ferric chloride solution was studied. The exposures were conducted according to ASTM G48-76, Method A. The influence of ferric chloride concentration and exposure temperature on the corrosion kinetics of these materials was evaluated. A mechanism is proposed to explain the associated morphology observed in the microstructures produced after exposure of these P/M alloys to the aggressive medium.

  14. Influence of Heat Input on the Content of Delta Ferrite in the Structure of 304L Stainless Steel GTA Welded Joints

    NASA Astrophysics Data System (ADS)

    Sejč, Pavol; Kubíček, Rastislav

    2011-12-01

    Welding of austenitic stainless steel has its specific issues, even when the weldability is considered good. The main problems of austenitic stainless steel welding are connected with its metallurgical weldability. The amount of the components presented in the structure of stainless steel welded joint affect its properties, therefore the understanding of the behavior of stainless steel during its welding is important for successful processing and allows the fabricators the possibility to manage the resulting issues. This paper is focused on the influence of heat input on the structural changes in GTA welded joints of austenitic stainless steel designated: ASTM SA TP 304L.

  15. Influence of low-temperature nitriding on the strain-induced martensite and laser-quenched austenite in a magnetic encoder made from 304L stainless steel

    PubMed Central

    Leskovšek, Vojteh; Godec, Matjaž; Kogej, Peter

    2016-01-01

    We have investigated the possibility of producing a magnetic encoder by an innovative process. Instead of turning grooves in the encoder bar for precise positioning, we incorporated the information in 304L stainless steel by transforming the austenite to martensite after bar extrusion in liquid nitrogen and marking it with a laser, which caused a local transformation of martensite back into austenite. 304L has an excellent corrosion resistance, but a low hardness and poor wear resistance, which limits its range of applications. However, nitriding is a very promising way to enhance the mechanical and magnetic properties. After low-temperature nitriding at 400 °C it is clear that both ε- and α′-martensite are present in the deformed microstructure, indicating the simultaneous stress-induced and strain-induced transformations of the austenite. The effects of a laser surface treatment and the consequent appearance of a non-magnetic phase due to the α′ → γ transformation were investigated. The EDS maps show a high concentration of nitrogen in the alternating hard surface layers of γN and α′N (expanded austenite and martensite), but no significantly higher concentration of chromium or iron was detected. The high surface hardness of this nitride layer will lead to steels and encoders with better wear and corrosion resistance. PMID:27492862

  16. Fracture and the formation of sigma phase, M[sub 23]C[sub 6], and austenite from delta-ferrite in an AISI 304L stainless steel

    SciTech Connect

    Tseng, C.C.; Shen, Y.; Thompson, S.W.; Krauss, G. . Dept. of Metallurgical and Materials Engineering); Mataya, M.C. )

    1994-06-01

    The decomposition of delta-ferrite and its effects on tensile properties and fracture of a hot-rolled AISI 304L stainless steel plate were studied. Magnetic response measurements of annealed specimens showed that the transformation rate of delta-ferrite was highest at 720 C. Transformation behavior was characterized by light microscopy, transmission electron microscopy, scanning electron microscopy, and energy-dispersive spectroscopy on thin foils. The initial transformation of delta-ferrite ([delta]) to austenite ([gamma]) and a chromium-rich carbide (M[sub 23]C[sub 6]) occurred by a lamellar eutectoid reaction, [sigma] [r reversible] M[sub 23]C[sub 6] + [gamma]. The extent of the reaction was limited by the low carbon content of the 304L plate, and the numerous, fine M[sub 23]C[sub 6] particles of the eutectoid structure provide microvoid nucleation sites in tensile specimens annealed at 720 C for short times. Sigma phase ([sigma]) formed as a result of a second eutectoid reaction, [delta] [r reversible] [sigma] + [gamma]. Brittle fracture associated with the plate-shaped sigma phase of the second eutectoid structure resulted in a significant decrease in reduction of area (RA) in the transverse tensile specimens. The RA for longitudinal specimens was not affected by the formation of sigma phase. Tensile strengths were little affected by delta-ferrite decomposition products in either longitudinal or transverse orientations.

  17. Microstructural changes in AISI 304L stainless steel due to surface machining: Effect on its susceptibility to chloride stress corrosion cracking

    NASA Astrophysics Data System (ADS)

    Ghosh, Swati; Kain, Vivekanand

    2010-08-01

    This study aims to understand the mechanism of increased SCC susceptibility of machined 304L stainless steel in chloride environment. Austenitic stainless steel grade 304L was surface machined up to a depth of 0.5 mm from the surface. In depth characterization was carried out by optical, scanning electron microscopic technique, hardness measurement and by EBSD and XRD studies. The stress corrosion cracking (SCC) susceptibility was estimated by exposing constant strained samples made up of machined and unmachined stainless steel to 5 M H 2SO 4 + 0.5 M NaCl solution at room temperature (28 °C) until cracking. In addition strips of machined and unmachined stainless steel were exposed to boiling MgCl 2 solution as per ASTM G36 to understand the effect of residual stress and strain generated due to machining on the SCC susceptibility. The study reveals that surface machining results in extensive grain refinement, strain induced martensite transformation and high magnitude of plastic deformation near the surface.

  18. Influence of low-temperature nitriding on the strain-induced martensite and laser-quenched austenite in a magnetic encoder made from 304L stainless steel.

    PubMed

    Leskovšek, Vojteh; Godec, Matjaž; Kogej, Peter

    2016-01-01

    We have investigated the possibility of producing a magnetic encoder by an innovative process. Instead of turning grooves in the encoder bar for precise positioning, we incorporated the information in 304L stainless steel by transforming the austenite to martensite after bar extrusion in liquid nitrogen and marking it with a laser, which caused a local transformation of martensite back into austenite. 304L has an excellent corrosion resistance, but a low hardness and poor wear resistance, which limits its range of applications. However, nitriding is a very promising way to enhance the mechanical and magnetic properties. After low-temperature nitriding at 400 °C it is clear that both ε- and α'-martensite are present in the deformed microstructure, indicating the simultaneous stress-induced and strain-induced transformations of the austenite. The effects of a laser surface treatment and the consequent appearance of a non-magnetic phase due to the α' → γ transformation were investigated. The EDS maps show a high concentration of nitrogen in the alternating hard surface layers of γN and α'N (expanded austenite and martensite), but no significantly higher concentration of chromium or iron was detected. The high surface hardness of this nitride layer will lead to steels and encoders with better wear and corrosion resistance. PMID:27492862

  19. Influence of low-temperature nitriding on the strain-induced martensite and laser-quenched austenite in a magnetic encoder made from 304L stainless steel

    NASA Astrophysics Data System (ADS)

    Leskovšek, Vojteh; Godec, Matjaž; Kogej, Peter

    2016-08-01

    We have investigated the possibility of producing a magnetic encoder by an innovative process. Instead of turning grooves in the encoder bar for precise positioning, we incorporated the information in 304L stainless steel by transforming the austenite to martensite after bar extrusion in liquid nitrogen and marking it with a laser, which caused a local transformation of martensite back into austenite. 304L has an excellent corrosion resistance, but a low hardness and poor wear resistance, which limits its range of applications. However, nitriding is a very promising way to enhance the mechanical and magnetic properties. After low-temperature nitriding at 400 °C it is clear that both ε- and α‧-martensite are present in the deformed microstructure, indicating the simultaneous stress-induced and strain-induced transformations of the austenite. The effects of a laser surface treatment and the consequent appearance of a non-magnetic phase due to the α‧ → γ transformation were investigated. The EDS maps show a high concentration of nitrogen in the alternating hard surface layers of γN and α‧N (expanded austenite and martensite), but no significantly higher concentration of chromium or iron was detected. The high surface hardness of this nitride layer will lead to steels and encoders with better wear and corrosion resistance.

  20. Materials Reliability Program: Environmental Fatigue Testing of Type 304L Stainless Steel U-Bends in Simulated PWR Primary Water (MRP-137)

    SciTech Connect

    R.Kilian

    2004-12-01

    Laboratory data generated in the past decade indicate a significant reduction in component fatigue life when reactor water environmental effects are experimentally simulated. However, these laboratory data have not been supported by nuclear power plant component operating experience. In recent comprehensive review of laboratory, component and structural test data performed through the EPRI Materials Reliability Program, flow rate was identified as a critical variable that was generally not considered in laboratory studies but applicable in plant operating environments. Available data for carbon/low-alloy steel piping components suggest that high flow is beneficial regarding the effects of a reactor water environment. Similar information is lacking for stainless steel piping materials. This report documents progress made to date in an extensive testing program underway to evaluate the effects of flow rate on the corrosion fatigue of 304L stainless steel under simulated PWR primary water environmental conditions.

  1. Analysis of cracking of co-extruded recovery boiler floor tubes

    SciTech Connect

    Keiser, J.R.; Taljat, B.; Wang, X.L.

    1997-08-01

    Cracking of the stainless steel layer in co-extruded 304L/SA210 tubing used in black liquor recovery boilers is being found in an ever-increasing number of North American pulp and paper mills. Because of the possibility of a tube failure, this is a significant safety issue, and, because of the extra time required for tube inspection and repair, this can become an economic issue as well. In a project funded by the U.S. Department of Energy and given wide support among paper companies, boiler manufacturers, and tube fabricators, studies are being conducted to determine the cause of the cracking and to identify alternate materials and/or operating procedures to prevent tube cracking. Examination of cracked tubes has permitted characterization of crack features, and transmission electron microscopy is providing information about the thermal history, particularly cyclic thermal exposures, that tubes have experienced. Neutron and x-ray diffraction techniques are being used to determine the residual stresses in as-fabricated tube panels and exposed tubes, and finite element modeling is providing information about the stresses the tubes experience during operation. Laboratory studies are being conducted to determine the susceptibility of the co-extruded 304L/SA210 tubes to stress corrosion cracking, thermal fatigue, and corrosion in molten smelt. This paper presents the current status of these studies. On the basis of all of these studies, recommendations for means to prevent tube cracking will be offered.

  2. Influence of cold plastic deformation on critical pitting potential of AISI 316 L and 304 L steels in an artificial physiological solution simulating the aggressiveness of the human body.

    PubMed

    Cigada, A; Mazza, B; Pedeferri, P; Sinigaglia, D

    1977-07-01

    The effect of cold working on critical pitting potential of AISI 316 L and 304 L steels in a buffered physiological solution has been studied. In particular, the importance of deformation degree, orientation of the specimen surface to the deformation direction, and cold working temperature in lowering the critical pitting potential is shown. PMID:873942

  3. Effect of internal heating during hot compression testing on the stress-strain behavior and hot working characteristics of Alloy 304L

    SciTech Connect

    Mataya, M.C.; Sackschewsky, V.E.

    1993-05-01

    Temperature change from conversion of deformation to internal heat, and its effect on stress-strain behavior of alloy 304L was investigated by initially isothermal (temperature of specimen, compression dies, environment equilibrated at initiation of test) uniaxial compression. Strain rate was varied 0.01 s{sup {minus}1} to 1 s{sup {minus}1} (thermal state of specimen varied from nearly isothermal to nearly adiabatic). Specimens were deformed at 750 to 1150 to a strain of 1. Change in temperature with strain was calculated via finite element analysis from measured stress-strain data and predictions were confirmed with thermocouples to verify the model. Temperature increased nearly linearly at the highest strain rate, consistent with temperature rise being a linear function of strain (adiabatic). As strain rate was lowered, heat transfer from superheated specimen to cooler dies caused sample temperature to increase and then decrease with strain as the sample thinned and specimen-die contact area increased. As-measured stress was corrected. Resulting isothermal flow curves were compared to predictions of a simplified method suggested by Thomas and Shrinivasan and differences are discussed. Strain rate sensitivity, activation energy for deformation, and flow curve peak associated with onset of dynamic recrystallization were determined from both as-measured and isothermal stress-strain data and found to vary widely. The impact of utilizing as-measured stress-strain data, not corrected for internal heating, on results of a number of published investigations is discussed.

  4. A Microstructural Study on the Observed Differences in Charpy Impact Behavior Between Hot Isostatically Pressed and Forged 304L and 316L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Cooper, Adam J.; Cooper, Norman I.; Bell, Andrew; Dhers, Jean; Sherry, Andrew H.

    2015-11-01

    With near-net shape technology becoming a more desirable route toward component manufacture due to its ability to reduce machining time and associated costs, it is important to demonstrate that components fabricated via Hot Isostatic Pressing (HIP) are able to perform to similar standards as those set by equivalent forged materials. This paper describes the results of a series of Charpy tests from HIP'd and forged 304L and 316L austenitic stainless steel, and assesses the differences in toughness values observed. The pre-test and post-test microstructures were examined to develop an understanding of the underlying reasons for the differences observed. The as-received microstructure of HIP'd material was found to contain micro-pores, which was not observed in the forged material. In tested specimens, martensite was detectable within close proximity to the fracture surface of Charpy specimens tested at 77 K (-196 °C), and not detected in locations remote from the fracture surface, nor was martensite observed in specimens tested at ambient temperatures. The results suggest that the observed changes in the Charpy toughness are most likely to arise due to differences in as-received microstructures of HIP'd vs forged stainless steel.

  5. Correlation of radiation-induced changes in microstructure/microchemistry, density and thermo-electric power of type 304L and 316 stainless steels irradiated in the Phénix reactor

    NASA Astrophysics Data System (ADS)

    Renault Laborne, Alexandra; Gavoille, Pierre; Malaplate, Joël; Pokor, Cédric; Tanguy, Benoît

    2015-05-01

    Annealed specimens of type 304L and 316 stainless steel and cold-worked 316 specimens were irradiated in the Phénix reactor in the temperature range 381-394 °C and to different damage doses up to 39 dpa. The microstructure and microchemistry of both 304L and 316 have been examined using the combination of the different techniques of TEM to establish the void swelling and precipitation behavior under neutron irradiation. TEM observations are compared with results of measurements of immersion density and thermo-electric power obtained on the same irradiated stainless steels. The similarities and differences in their behavior on different scales are used to understand the factors in terms of the chemical composition and metallurgical state of steels, affecting the precipitation under irradiation and the swelling behavior. Irradiation induces the formation of some precipitate phases (e.g., M6C and M23C6-type carbides, and γ'- and G-phases), Frank loops and cavities. According to the metallurgical state and chemical composition of the steel, the amount of each type of radiation-induced defects is not the same, affecting their density and thermo-electric power.

  6. Analysis of composite tube cracking in recovery boiler floors

    SciTech Connect

    Keiser, J.R.; Taljat, B.; Wang, X.L.; Maziasz, P.J.; Hubbard, C.R.; Swindeman, R.W.; Singbeil, D.L.; Prescott, R.

    1996-08-01

    Cracking of co-extruded (generally identified as composite) floor tubes in kraft black liquor recovery boilers was first observed in Scandinavia, but this problem has now been found in many North American boilers. In most cases, cracking in the outer 304L stainless steel has not progressed into the carbon steel, but the potential for such crack propagation is a cause of concern. A multidimensional study has been initiated to characterize the cracking seen in composite floor tubes, to measure the residual stresses resulting from composite tube fabrication, and to predict the stresses in tubes under operating conditions. The characterization studies include review of available reports and documents on composite tube cracking, metallographic examination of a substantial number of cracked tubes, and evaluation of the dislocation structure in cracked tubes. Neutron and X-ray diffraction are being used to determine the residual stresses in composite tubes from two major manufacturers, and finite element analysis is being used to predict the stresses in the tubes during normal operation and under conditions where thermal fluctuations occur.

  7. Tube support

    DOEpatents

    Mullinax, Jerry L.

    1988-01-01

    A tube support for supporting horizontal tubes from an inclined vertical support tube passing between the horizontal tubes. A support button is welded to the vertical support tube. Two clamping bars or plates, the lower edges of one bearing on the support button, are removably bolted to the inclined vertical tube. The clamping bars provide upper and lower surface support for the horizontal tubes.

  8. Feeding Tubes

    MedlinePlus

    ... administer the TPN. Tubes Used for Enteral Feeds NG (Nasogastric Tube) A flexible tube is placed via ... down through the esophagus into the stomach. The NG tube can be used to empty the stomach ...

  9. Ear Tubes

    MedlinePlus

    ... Meeting Calendar Find an ENT Doctor Near You Ear Tubes Ear Tubes Patient Health Information News media ... and throat specialist) may be considered. What are ear tubes? Ear tubes are tiny cylinders placed through ...

  10. Infrared variability of SS 433

    NASA Technical Reports Server (NTRS)

    Kodaira, K.; Nakada, Y.; Backman, D. E.

    1985-01-01

    New JHKLM photometry of SS 433 showing short time scale variabilities is reported for the period of 1983 July 16-22 UT. The entire body of infrared data included in this paper, Giles et al. (1980), and Catchpole et al. (1981), is examined with reference to periods of 164 days and 13.08 days. Comparison of the infrared light curves with the optical light curves of Leibowitz et al. (1984) makes it possible to conclude, within the context of an accretion disk model, that the majority of the infrared flux in the SS 433 system comes from the disk, and that the hot spot responsible for the 'hump' in the visual and infrared light curves has a color similar to the average of the disk. A two-dimensional Fourier analysis of the infrared data suggests that the brightness maximum occurs when, seen from the compact star, the noncompact companion passes through a fixed elongation relative to the disk line of nodes with the orbital plane, if the precession is prograde.

  11. TUBE TESTER

    DOEpatents

    Gittings, H.T. Jr.; Kalbach, J.F.

    1958-01-14

    This patent relates to tube testing, and in particular describes a tube tester for automatic testing of a number of vacuum tubes while in service and as frequently as may be desired. In it broadest aspects the tube tester compares a particular tube with a standard tube tarough a difference amplifier. An unbalanced condition in the circuit of the latter produced by excessive deviation of the tube in its characteristics from standard actuates a switch mechanism stopping the testing cycle and indicating the defective tube.

  12. Overview of the DOE studies of recovery boiler floor tube cracking

    SciTech Connect

    Keiser, J.R.; Taljat, B.; Wang, X.L.

    1998-03-01

    Cracking of the stainless steel layer of coextruded 304L/SA210 recovery boiler floor tubes has been observed in an increasing number of black liquor recovery boilers. Because failure of such tubes is a serious safety concern as well as an economic issue, this project was initiated with the objective of identifying alternate materials or process changes that would prevent tube cracking. Tensile stresses are essential for the most likely failure mechanisms, i.e., fatigue or stress corrosion cracking, therefore stresses were measured at room temperature and modeling was used to predict stresses under operating conditions. Laboratory studies have identified conditions under which composite tubes crack due to thermal fatigue and stress corrosion. Floor tube temperature measurements have defined the magnitude and frequency of temperature fluctuations experienced by such tubes, and smelt corrosion studies have measured the degradation rate when molten smelt comes in contact with tubes. Based on these observations, certain materials appear more likely to resist cracking and certain process changes should help avoid conditions that cause composite tube cracking.

  13. Cryogenic material properties of stainless steel tube-to-flange welds

    NASA Astrophysics Data System (ADS)

    Siewert, T. A.; McCowan, C. N.; Vigliotti, D. P.

    The mechanical properties of stainless steel tube-to-flange welds for a cryogenic piping application were measured. A planar specimen was developed to duplicate the constraint, loading and heat-sink properties of the circular joint, while reducing preparation time and cost. Specimens were evaluated containing welds between the tube material (21 Cr-6Ni-9Mn) and the three stainless steels being considered for the flange materials: type 304L, type 316L and 21 Cr-6Ni-9Mn. The mechanical property tests consisted of three phases: simple tensile testing to failure, tensile testing of notched specimens (where the notch simulated fabrication flaws) and fatigue testing of notched specimens for the 4 × 10 4 cycle design life of the structure. The type 316L stainless steel flange produced welds with the best combination of strength and ductility at 295 and 4 K in all three phases of testing.

  14. Welding of Vanadium, Tantalum, 304L and 21-6-9 Stainless Steels, and Titanium Alloys at Lawrence Livermore National Laboratory using a Fiber Delivered 2.2 kW Diode Pumped CW Nd:YAG Laser

    SciTech Connect

    Palmer, T; Elmer, J; Pong, R; Gauthier, M

    2006-06-16

    This report summarizes the results of a series of laser welds made between 2003 and 2005 at Lawrence Livermore National Laboratory (LLNL). The results are a compilation of several, previously unpublished, internal LLNL reports covering the laser welding of vanadium, tantalum, 304L stainless steel, 21-6-9 (Nitronic 40) steel, and Ti-6Al-4V. All the welds were made using a Rofin Sinar DY-022 diode pumped continuous wave Nd:YAG laser. Welds are made at sharp focus on each material at various power levels and travel speeds in order to provide a baseline characterization of the performance of the laser welder. These power levels are based on measurements of the output power of the laser system, as measured by a power meter placed at the end of the optics train. Based on these measurements, it appears that the system displays a loss of approximately 10% as the beam passes through the fiber optic cable and laser optics. Since the beam is delivered to the fixed laser optics through a fiber optic cable, the effects of fiber diameter are also briefly investigated. Because the system utilizes 1:1 focusing optics, the laser spot size at sharp focus generally corresponds to the diameter of the fiber with which the laser is delivered. Differences in the resulting weld penetration in the different materials system are prevalent, with the welds produced on the Nitronic 40 material displaying the highest depths (> 5 mm) and minimal porosity. A Primes focusing diagnostic has also been installed on this laser system and used to characterize the size and power density distribution of the beams as a function of both power and focus position. Further work is planned in which this focusing diagnostic will be used to better understand the effects of changes in beam properties on the resulting weld dimensions in these and other materials systems.

  15. Image tubes

    SciTech Connect

    Csorba, I.P.

    1985-01-01

    This text provides a wealth of valuable, hard-to-find data on electron optics, imaging, and image intensification systems. The author explains details of image tube theory, design, construction, and components. He includes material on the design and operation of camera tubes, power components, and secondary electron emitters, as well as data on photomultiplier tubes and electron guns.

  16. Corrosion erosion test of SS316 in flowing Pb Bi

    NASA Astrophysics Data System (ADS)

    Kikuchi, K.; Kurata, Y.; Saito, S.; Futakawa, M.; Sasa, T.; Oigawa, H.; Wakai, E.; Miura, K.

    2003-05-01

    Corrosion tests of austenitic stainless tube were done under flowing Pb-Bi conditions for 3000 h at 450 °C. Specimens were 316SS produced as a tubing form with 13.8 mm outer diameter, 2 mm thickness and 40 cm length. During operation, maximum temperature, temperature difference and flow velocity of Pb-Bi at the specimen were kept at 450, 50 °C, and 1 m/s, respectively. After the test, specimen and components of the loop were cut and examined by optical microscope, SEM, EDX, WDX and X-ray diffraction. Pb-Bi adhered on the surface of the specimen even after Pb-Bi was drained out to the storage tank from the circulating loop. Results differed from a stagnant corrosion test in that the specimen surface became rough and the corrosion rate was maximally 0.1 mm/3000 h. Mass transfer from the high temperature to the lower temperature area was observed: crystals of Fe-Cr were found on the tube surface in the low-temperature region. The sizes of crystals varied from 0.1 to 0.2 mm. The depositing crystals were ferrite grains and the chemical composition ratio (mass%) of Fe to Cr was 9:1.

  17. Experience of composite tubes in municipal waste incinerators

    SciTech Connect

    Wilson, A.; Forsberg, U.; Noble, J.

    1997-08-01

    The environment in waste incineration plants contains high concentrations of chloride, alkalis, sulfur, and low temperature melting species. This corrosive environment along with a need to fulfill the pressure vessel code requirement, calls for a dual purpose material in the waterwalls and superheaters of the boiler. Composite tubes consisting of a corrosion resistant cladding metallurgically bonded to the load-bearing core, make it possible to optimize both of the aforementioned requirements while meeting the demands for higher efficiency in waste-to-energy plants. During the last years several field tests of composite tubes have been performed. The experience of these tests will be the subject of this paper. Alloy 825 mod, Alloy 28, Alloy 65 and Alloy 625 were evaluated as superheater tubes. Among these the Alloy 625 showed the best performance and it was estimated that the corrosion rate is about 10--20 times lower when compared to carbon steel. The superior corrosion resistance of Alloy 625 was due to its high Mo content in combination with either a low Fe content or a high Nb content. All tested alloys suffered from corrosion near sootblowers. However, Alloy 625 corroded but at a considerably lower rate than the other materials. At a material temperature of about 540 C the wastage of Alloy 625 was 0.2 {micro}m/h. Alloy 28 composite tube in waterwalls showed a corrosion rate that is about 8 times lower than carbon steels and a factor 2 to 3 better than type 304L. Composite Alloy 825 as screen tubes exhibited a similar corrosion rate as weld overlay Alloy 625. When experiencing short operating lives and high maintenance costs, due to corrosion, in waste incineration boilers, composite tubes provide an interesting alternative to other corrosion protection methods.

  18. Intermittency in 200 GeV/nucleon S+S collisions

    SciTech Connect

    Jacobs, P.; Bloomer, M.A.

    1992-03-01

    We have studied one and two-dimensional intermittency in S+S collisions at 200 GeV/nucleon in a high statistics electronic measurement at the CERN SPS using pad-readout streamer tubes. We observe no intermittency signal beyond that produced by folding the Fritiof event generator with a detailed model of our detector. Even though the observed signal contains significant distortions due to experimental effects, we show that we are sensitive to intermittency in the collision.

  19. Feeding tube insertion - gastrostomy

    MedlinePlus

    ... tube insertion; G-tube insertion; PEG tube insertion; Stomach tube insertion; Percutaneous endoscopic gastrostomy tube insertion ... and down the esophagus, which leads to the stomach. After the endoscopy tube is inserted, the skin ...

  20. Nasogastric feeding tube

    MedlinePlus

    Feeding - nasogastric tube; NG tube; Bolus feeding; Continuous pump feeding; Gavage tube ... A nasogastric tube (NG tube) is a special tube that carries food and medicine to the stomach through the nose. It can be ...

  1. Middle Level SS&C Energy Series.

    ERIC Educational Resources Information Center

    Crow, Linda W.; Aldridge, Bill G.

    The project on Scope Sequence and Coordination of Secondary School Science (SS&C) was initiated by the National Science Teachers Association (NSTA) and recommends that all students study science every year and advocates carefully sequenced, well-coordinated instruction in biology, chemistry, earth/space science, and physics. This document…

  2. NARSTO EPA SS HOUSTON DMA DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON DMA DATA Project Title:  NARSTO ... Analyzer Optical Counter Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston DMA Guide Houston Project Plan  (PDF) Houston ...

  3. NARSTO EPA SS HOUSTON RAPID SPMS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON RAPID SPMS DATA Project Title:  NARSTO ... Single-particle Mass Spectrometer Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston SPMS Guide Houston Project Plan  (PDF) Houston ...

  4. Protective tubes for sodium heated water tubes

    DOEpatents

    Essebaggers, Jan

    1979-01-01

    A heat exchanger in which water tubes are heated by liquid sodium which minimizes the results of accidental contact between the water and the sodium caused by failure of one or more of the water tubes. A cylindrical protective tube envelopes each water tube and the sodium flows axially in the annular spaces between the protective tubes and the water tubes.

  5. Development of clad boiler tubes extruded from bimetallic centrifugal castings

    NASA Astrophysics Data System (ADS)

    Sponseller, D. L.; Timmons, G. A.; Bakker, W. T.

    1998-04-01

    Wrought tubes of T-11 steel, externally clad with SS310, have been produced by a new method (U.S. Patent 5,558,150). The alloys were united directly from the molten state by centrifugal casting. In the optimum process, temperatures were controlled to prevent meltback of the SS310 outer layer by the higher melting T-11 stream. Hollow extrusion billets were prepared from the heavy-walled cast bimetallic tubes and successfully hot extruded (at a ratio of 13.4) to 84-mm (3.3 in.) OD X 64-mm (2.5-in.) ID tubes, and (at a ratio of 37.6) to 51-mm (2-in.) OD X 38-mm (1.5-in.) ID tubes. In all, 10 castings were produced, and 12 billets were extruded to tubes. For the most part, thicknesses of the cladding and of the tube wall are rather uniform around the circumference and from end to end of the tubes. Hardness and tensile properties of annealed 51-mm (2-in.) tubes are uniform from end to end of a tube, and between tubes, and readily conform to ASTM A 213; tubes satisfy the flattening and flaring requirements of ASTM A 450. The cladding is metallurgically bonded to the base metal, as revealed by metallography, and by two tests developed for this study: a bond shear strength test and a twist test. In the latter test, rings 3.1 mm (0.125 in.) in thickness are slotted and severely twisted with a special tool. In tubes made by the optimum process, minute fissures that form adjacent to some of the pressure points during twist testing occupy just 3 % of the bond-line length. Cost estimates for commercial production of 51-mm (2-in.) tubes via the centrifugal casting route suggest that such tubes should be considerably less expensive than conventionally clad tubes (extruded from composite billets assembled from heavy-walled wrought tubes).

  6. Ear tube insertion

    MedlinePlus

    Myringotomy; Tympanostomy; Ear tube surgery; Pressure equalization tubes; Ventilating tubes; Ear infection - tubes; Otitis - tubes ... trapped fluid can flow out of the middle ear. This prevents hearing loss and reduces the risk ...

  7. 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.

  8. 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.

  9. An Ss Model with Adverse Selection.

    ERIC Educational Resources Information Center

    House, Christopher L.; Leahy, John V.

    2004-01-01

    We present a model of the market for a used durable in which agents face fixed costs of adjustment, the magnitude of which depends on the degree of adverse selection in the secondary market. We find that, unlike typical models, the sS bands in our model contract as the variance of the shock increases. We also analyze a dynamic version of the model…

  10. Efficacy of Salpingography and Transcervical Recanalization in Diagnosis, Categorization, and Treatment of Fallopian Tube Obstruction

    SciTech Connect

    Lang, Erich K.; Dunaway, Herbert E.

    2000-11-15

    Purpose: The efficacy of selective salpingography (SS) and transcervical recanalization (TCR) in diagnosis, categorization, and determination of optimal treatment modality for fallopian tube obstruction was investigated.Methods: SS and, in some patients, TCR was performed in 430 patients with a diagnosis of obstruction of one or both fallopian tubes, as determined by hysterosalpingograms (HSG). All patients (age 21-46 years) had an infertility problem for at least 18 months.Results: In 196 patients, 325 tubes were patent on SS. TCR recanalized 243 tubes in 176 patients. Disease of the distal tube was demonstrated in 66 patients. There were 39 live babies in a group of 176 patients with successful TCR. Best live birth rate was in 7 of 12 (58%) patients with underlying endometriosis, followed by postsurgical strictures in inflammatory disease, 6 of 31 (19%), and salpingitis isthmica nodosa in 25 of 168 (15%). There were no pregnancies in patients with cobblestone pattern of the distal tubes.Conclusions: SS and TCR were capable of correcting obstruction of the proximal tubes in 243 of 465 tubes in 176 of 234 patients (75%). With patency of the proximal tube restored, the distal tube could be assessed for changes indicative of damage to the ciliated epithelium which was likely to reduce the ability to become pregnant. This allowed for the triage of patients into groups benefiting from the relatively inexpensive and low complication TCR or patients in need of in vitro fertilization or similar assisted reproductive technologies.

  11. Tube Feedings.

    ERIC Educational Resources Information Center

    Plummer, Nancy

    This module on tube feedings is intended for use in inservice or continuing education programs for persons who work in long-term care. Instructor information, including teaching suggestions and a listing of recommended audiovisual materials and their sources appear first. The module goal and objectives are then provided. A brief discussion follows…

  12. The Power of SS 433's Jets

    NASA Technical Reports Server (NTRS)

    Band, David F.

    1999-01-01

    We observed SS 433 for the third time with RXTE, this time simultaneously with a Nobeyama millimeter band monitoring campaign. These observations extended the RXTE coverage of SS 433's precession phases. and once again monitored the source during a binary eclipse. Our AO-2 campaign of a joint RXTE-VLBA-VLA-MERLIN observation was delayed to little more than a month before the AO-3 observations. We also had an AO-1 observation of SS 433. In each case we observed an eclipse of the compact ob'ect by the companion star, and had contemporaneous optical observations. We are analyzing all three sets of observations together. A publication is in preparation; Its completion will be supported by the remaining AO-2 funds. Here I will summarize the general results and point out the relevant features of the AO-3 observations. The spectrum is detected to approx. 50 keV, which is entirely within the PCA energy band. We find that the HEXTE data do not add significantly to the spectrum, and most of our fits are without HEXTE. We find that the continuum can be fit with a power law with an exponential cutoff; the photon index is usually approx. 1.4. A line at approx. 6.4 keV is definitely required, and the fits improve significant, if we add a second line, also with an energy in the iron K(alpha) complex, and an absorption edge. The edge usually has an energy of approx. 5.8 keV, which does not correspond to any known physical feature. and may be an instrumental artifact. This is under further investigation.

  13. Angular glass tubing drawn from round tubing

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Round glass tubing softened in a furnace is drawn over a shaped plug or mandel to form shapes with other than a circular cross section. Irregularly shaped tubing is formed without limitations on tube length or wall thickness.

  14. Electron tube

    DOEpatents

    Suyama, Motohiro; Fukasawa, Atsuhito; Arisaka, Katsushi; Wang, Hanguo

    2011-12-20

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  15. QUANTIZING TUBE

    DOEpatents

    Jensen, A.S.; Gray, G.W.

    1958-07-01

    Beam deflection tubes are described for use in switching or pulse amplitude analysis. The salient features of the invention reside in the target arrangement whereby outputs are obtained from a plurality of collector electrodes each correspondlng with a non-overlapping range of amplitudes of the input sigmal. The tube is provded with mcans for deflecting the electron beam a1ong a line in accordance with the amplitude of an input signal. The target structure consists of a first dymode positioned in the path of the beam wlth slots spaced a1ong thc deflection line, and a second dymode posltioned behind the first dainode. When the beam strikes the solid portions along the length of the first dymode the excited electrons are multiplied and collected in separate collector electrodes spaced along the beam line. Similarly, the electrons excited when the beam strikes the second dynode are multiplied and collected in separate electrodes spaced along the length of the second dyode.

  16. Neutron tubes

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  17. Chest tube insertion

    MedlinePlus

    Chest drainage tube insertion; Insertion of tube into chest; Tube thoracostomy; Pericardial drain ... When your chest tube is inserted, you will lie on your side or sit partly upright, with one arm over your ...

  18. Tube Feeding Troubleshooting Guide

    MedlinePlus

    ... profile tube also has a stem length). Note: NG and NJ tubes (that go through a person’s ... Immediate Action: • Discontinue feeding. • If you have an NG or NJ tube, and the tube is curled ...

  19. Status Report on Studies of Recovery Boiler Composite Floor Tube Cracking

    SciTech Connect

    Eng, P.; Frederick, L.A.; Hoffmann, C.M.; Keiser, J.R.; Mahmood, J.; Maziasz, P.J.; Prescott, R.; Sarma, G.B.; Singbeil, D.L.; Singh, P.M.; Swindeman, R.W.; Wang, X.-L.

    1999-09-12

    Cracking of the stainless steel layer of co-extruded 304L stainless steel/SA210 Gd A 1 carbon steel black liquor recovery boiler floor tubes has been identified as one of the most serious material problems in the pulp and paper industry. A DOE-funded study was initiated in 1995 with the goal of determining the cause of and possible solutions to this cracking problem. These studies have characterized tube cracking as well as the chemical and thermal environment and stress state of floor tubes. Investigations of possible cracking mechanisms indicate that stress corrosion cracking rather than thermal fatigue is a more likely cause of crack initiation. The cracking mechanism appears to require the presence of hydrated sodium sulfide and is most likely active during shut-downs and/or start-ups. Based on these results and operating experience, certain alloys appear to be more resistant than others to cracking in the floor environment, and certain operating practices appear to significantly lessen the likelihood of cracking. This report is the latest in a series of progress reports presented on this project.

  20. Development of clad boiler tubes extruded from bimetallic centrifugal castings

    SciTech Connect

    Sponseller, D.L.; Bakker, W.T.; Timmons, G.A.

    1998-04-01

    Wrought tubes of T-11 steel, externally clad with SS310, have been produced by a new method. The alloys were united directly from the molten state by centrifugal casting. In the optimum process, temperatures were controlled to prevent meltback of the SS310 outer layer by the higher melting T-11 stream. Hollow extrusion billets were prepared from the heavy-walled cast bimetallic tubes and successfully hot extruded to 84-mm OD x 64-mm ID tubes, and to 51-mm OD x 38-mm ID tubes. For the most part, thicknesses of the cladding and of the tube wall are rather uniform around the circumference and from end to end of the tubes. Hardness and tensile properties of annealed 51-mm tubes are uniform from end to end of a tube, and between tubes, and readily conform to ASTM A 213; tubes satisfy the flattening and flaring requirements of ASTM A 450. The cladding is metallurgically bonded to be base metal, as revealed by metallography, and by two tests developed for this study: a bond shear strength test and a twist test. In the latter test, rings 3.1 mm in thickness are slotted and severely twisted with a special tool. In tubes made by the optimum process, minute fissures that form adjacent to some of the pressure points during twist testing occupy just 3% of the bond-line length. Cost estimates for commercial production of 51-mm tubes via the centrifugal casting route suggest that such tubes should be considerably less expensive than conventionally clad tubes (extruded from composite billets assembled from heavy-walled wrought tubes). Such tubes should be attractive for the following applications in utility boilers: high-corrosion areas of existing coal-fired boilers, in both steam-generating tubes and superheaters; water walls, screen tubes, and superheater tubes of municipal waste-incineration boilers; future ultra super-critical boilers operating a higher temperatures and pressures; and steam-generating tubes of Syngas coolers of integrated coal gasification power plants.

  1. Accretion disk structure in SS Cygni

    NASA Astrophysics Data System (ADS)

    Hessman, F. V.

    1987-02-01

    High-resolution coude observations of nonaxisymmetric line emission from the dwarf nova SS Cygni are presented. By subtracting the constant line component, the asymmetric line emission responsible for the observed phase shift between the absorption and emission line radial velocity curves can be isolated. The extra emission is a large fraction of the total line emission and extends to large velocities (of about 1500 km/sec). The phase stability of the emission demands a large-scale structure which is fixed in the frame of the binary. A magnetic origin of the excitation cannot be ruled out but is implausible. A simple explanation is that the accretion stream from the companion star is able to spill over the edge of the disk, introducing emission at noncircular velocities and most likely disturbing the upper layers of the accretion disk.

  2. WFC3 SS UVIS Spare Tungsten Lamp

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    2012-10-01

    Part of side switch activities.This proposal will verify the operation of the spare UVIS channel calsystem tungsten lamp. Internal flatfields will be obtained in one filter from each of the twelve filter wheels, providing an initial baseline and comparison for those taken with the primary lamp {WF09}. Filters for this proposal were chosen based upon a balance of multiple factors: reasonable countrate with calsystem tungsten lamp {no long exposure times}, science priority of the filter, overall coverage of UVIS wavelength regime, and slot location in the wheel. Exposures will be taken in the default full-frame, four-amp, unbinned readout mode.This proposal corresponds to the spare lamp portion of SS SMOV activity ID: WF09b

  3. MULTIWAVELENGTH OBSERVATIONS OF THE SS 433 JETS

    SciTech Connect

    Marshall, Herman L.; Canizares, Claude R.; Schulz, Norbert S.; Nowak, Michael; Hillwig, Todd; Mioduszewski, Amy; Rupen, Michael; Heinz, Sebastian E-mail: crc@space.mit.edu E-mail: mnowak@space.mit.edu E-mail: amiodusz@nrao.edu E-mail: heinzs@astro.wisc.edu

    2013-09-20

    We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and Very Long Baseline Array observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3 × 10{sup 14} cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 ± 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise >50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to ∼> 2 × 10{sup 12} cm. The base jet density is in the range 10{sup 10-13} cm{sup –3}, in contrast to our previous estimate based on the Si XIII triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 15 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.

  4. Multiwavelength Observations of the SS 433 Jets

    NASA Astrophysics Data System (ADS)

    Marshall, Herman L.; Canizares, Claude R.; Hillwig, Todd; Mioduszewski, Amy; Rupen, Michael; Schulz, Norbert S.; Nowak, Michael; Heinz, Sebastian

    2013-09-01

    We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and Very Long Baseline Array observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3 × 1014 cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 ± 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise >50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to >~ 2 × 1012 cm. The base jet density is in the range 1010-13 cm-3, in contrast to our previous estimate based on the Si XIII triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 15 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.

  5. Tube furnace

    DOEpatents

    Foster, Kenneth G.; Frohwein, Eugene J.; Taylor, Robert W.; Bowen, David W.

    1991-01-01

    A vermiculite insulated tube furnace is heated by a helically-wound resistance wire positioned within a helical groove on the surface of a ceramic cylinder, that in turn is surroundingly disposed about a doubly slotted stainless steel cylindrical liner. For uniform heating, the pitch of the helix is of shorter length over the two end portions of the ceramic cylinder. The furnace is of large volume, provides uniform temperature, offers an extremely precise programmed heating capability, features very rapid cool-down, and has a modest electrical power requirement.

  6. Tube furnace

    SciTech Connect

    Foster, K.G.; Frohwein, E.J.; Taylor, R.W.; Bowen, D.W.

    1990-12-31

    A vermiculite insulated tube furnace is heated by a helically-wound resistance wire positioned within a helical groove on the surface of a ceramic cylinder, that in turn is surroundingly disposed about a doubly slotted stainless steel cylindrical liner. For uniform heating, the pitch of the helix is of shorter length over the two end portions of the ceramic cylinder. The furnace is of large volume, provides uniform temperature, offers an extremely precise programmed heating capability, features very rapid cool-down, and has a modest electrical power requirement.

  7. Tube furnace

    SciTech Connect

    Foster, K.G.; Frohwein, E.J.; Taylor, R.W.; Bowen, D.W.

    1990-01-01

    A vermiculite insulated tube furnace is heated by a helically-wound resistance wire positioned within a helical groove on the surface of a ceramic cylinder, that in turn is surroundingly disposed about a doubly slotted stainless steel cylindrical liner. For uniform heating, the pitch of the helix is of shorter length over the two end portions of the ceramic cylinder. The furnace is of large volume, provides uniform temperature, offers an extremely precise programmed heating capability, features very rapid cool-down, and has a modest electrical power requirement.

  8. Collapse Tubes

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02154 Collapse Tubes

    The discontinuous channels in this image are collapsed lava tubes.

    Image information: VIS instrument. Latitude -19.7N, Longitude 317.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  9. Tapered pulse tube for pulse tube refrigerators

    DOEpatents

    Swift, Gregory W.; Olson, Jeffrey R.

    1999-01-01

    Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

  10. Tube-in-tube thermophotovoltaic generator

    SciTech Connect

    Ashcroft, John; Campbell, Brian; DePoy, David

    1998-01-01

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.

  11. Tube-in-tube thermophotovoltaic generator

    DOEpatents

    Ashcroft, J.; Campbell, B.; DePoy, D.

    1998-06-30

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell. 8 figs.

  12. A tube-in-tube thermophotovoltaic generator

    SciTech Connect

    Ashcroft, J.; Campbell, B.; Depoy, D.

    1996-12-31

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.

  13. The reproducible radio outbursts of SS Cygni

    NASA Astrophysics Data System (ADS)

    Russell, T. D.; Miller-Jones, J. C. A.; Sivakoff, G. R.; Altamirano, D.; O'Brien, T. J.; Page, K. L.; Templeton, M. R.; Körding, E. G.; Knigge, C.; Rupen, M. P.; Fender, R. P.; Heinz, S.; Maitra, D.; Markoff, S.; Migliari, S.; Remillard, R. A.; Russell, D. M.; Sarazin, C. L.; Waagen, E. O.

    2016-08-01

    We present the results of our intensive radio observing campaign of the dwarf nova SS Cyg during its 2010 April outburst. We argue that the observed radio emission was produced by synchrotron emission from a transient radio jet. Comparing the radio light curves from previous and subsequent outbursts of this system (including high-resolution observations from outbursts in 2011 and 2012) shows that the typical long and short outbursts of this system exhibit reproducible radio outbursts that do not vary significantly between outbursts, which is consistent with the similarity of the observed optical, ultraviolet and X-ray light curves. Contemporaneous optical and X-ray observations show that the radio emission appears to have been triggered at the same time as the initial X-ray flare, which occurs as disk material first reaches the boundary layer. This raises the possibility that the boundary region may be involved in jet production in accreting white dwarf systems. Our high spatial resolution monitoring shows that the compact jet remained active throughout the outburst with no radio quenching.

  14. The reproducible radio outbursts of SS Cygni

    NASA Astrophysics Data System (ADS)

    Russell, T. D.; Miller-Jones, J. C. A.; Sivakoff, G. R.; Altamirano, D.; O'Brien, T. J.; Page, K. L.; Templeton, M. R.; Körding, E. G.; Knigge, C.; Rupen, M. P.; Fender, R. P.; Heinz, S.; Maitra, D.; Markoff, S.; Migliari, S.; Remillard, R. A.; Russell, D. M.; Sarazin, C. L.; Waagen, E. O.

    2016-08-01

    We present the results of our intensive radio observing campaign of the dwarf nova SS Cyg during its 2010 April outburst. We argue that the observed radio emission was produced by synchrotron emission from a transient radio jet. Comparing the radio light curves from previous and subsequent outbursts of this system (including high-resolution observations from outbursts in 2011 and 2012) shows that the typical long and short outbursts of this system exhibit reproducible radio outbursts that do not vary significantly between outbursts, which is consistent with the similarity of the observed optical, ultraviolet and X-ray light curves. Contemporaneous optical and X-ray observations show that the radio emission appears to have been triggered at the same time as the initial X-ray flare, which occurs as disc material first reaches the boundary layer. This raises the possibility that the boundary region may be involved in jet production in accreting white dwarf systems. Our high spatial resolution monitoring shows that the compact jet remained active throughout the outburst with no radio quenching.

  15. Mechanochemical regulations of RPA's binding to ssDNA

    NASA Astrophysics Data System (ADS)

    Chen, Jin; Le, Shimin; Basu, Anindita; Chazin, Walter J.; Yan, Jie

    2015-03-01

    Replication protein A (RPA) is a ubiquitous eukaryotic single-stranded DNA (ssDNA) binding protein that serves to protect ssDNA from degradation and annealing, and as a template for recruitment of many downstream factors in virtually all DNA transactions in cell. During many of these transactions, DNA is tethered and is likely subject to force. Previous studies of RPA's binding behavior on ssDNA were conducted in the absence of force; therefore the RPA-ssDNA conformations regulated by force remain unclear. Here, using a combination of atomic force microscopy imaging and mechanical manipulation of single ssDNA tethers, we show that force mediates a switch of the RPA bound ssDNA from amorphous aggregation to a much more regular extended conformation. Further, we found an interesting non-monotonic dependence of the binding affinity on monovalent salt concentration in the presence of force. In addition, we discovered that zinc in micromolar concentrations drives ssDNA to a unique, highly stiff and more compact state. These results provide new mechanochemical insights into the influences and the mechanisms of action of RPA on large single ssDNA.

  16. Mechanochemical regulations of RPA's binding to ssDNA.

    PubMed

    Chen, Jin; Le, Shimin; Basu, Anindita; Chazin, Walter J; Yan, Jie

    2015-01-01

    Replication protein A (RPA) is a ubiquitous eukaryotic single-stranded DNA (ssDNA) binding protein that serves to protect ssDNA from degradation and annealing, and as a template for recruitment of many downstream factors in virtually all DNA transactions in cell. During many of these transactions, DNA is tethered and is likely subject to force. Previous studies of RPA's binding behavior on ssDNA were conducted in the absence of force; therefore the RPA-ssDNA conformations regulated by force remain unclear. Here, using a combination of atomic force microscopy imaging and mechanical manipulation of single ssDNA tethers, we show that force mediates a switch of the RPA bound ssDNA from amorphous aggregation to a much more regular extended conformation. Further, we found an interesting non-monotonic dependence of the binding affinity on monovalent salt concentration in the presence of force. In addition, we discovered that zinc in micromolar concentrations drives ssDNA to a unique, highly stiff and more compact state. These results provide new mechanochemical insights into the influences and the mechanisms of action of RPA on large single ssDNA. PMID:25787788

  17. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  18. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  19. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  20. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  1. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  2. SS1 (NAL1)- and SS2-Mediated Genetic Networks Underlying Source-Sink and Yield Traits in Rice (Oryza sativa L.)

    PubMed Central

    Wu, Yuan; Zheng, Tian-Qing; Wang, Yong-Hong; Zhao, Xiu-Qin; Cui, Yan-Ru; Chen, Kai; Zhang, Qiang; Lin, Hong-Xuan; Li, Jia-Yang; Li, Zhi-Kang

    2015-01-01

    Source leaf/sink capacity (SS) traits are important determinants of grain yield (GY) of rice. To understand the genetic basis of the SS relationship in rice, five SS and GY traits of rice were genetically dissected using two reciprocal introgression populations. Seventy-three QTL affecting the SS and GY traits were identified, most of which were detected in one of the parental genetic backgrounds (GBs). Two major QTL at bins 4.7 (SS1) and 3.12 (SS2) were associated consistently with all measured SS and yield traits in both GBs across two contrasting environments. Strong interactions between SS1/SS2 and the detected QTL led us to the discovery of genetic networks affecting the SS and GY traits. The SS1 acted as a regulator controlling two groups of downstream QTL affecting the source leaf width and grain number per panicle (GNP). SS2 functioned as a regulator positively regulating different groups of downstream QTL affecting the source leaf length, GNP, grain weight, and GY. Map-based cloning of SS1 indicates that SS1 is NAL1 involved in polar auxin/IAA transport. Different alleles at NAL1 were apparently able to qualitatively and/or quantitatively control the IAA transport from the apical meristem to different plant tissues and thus regulate those downstream loci/pathways controlling different SS traits of rice. There was a functional allele and a non-functional mutation in the parents at each of the QTL downstream of SS1 or SS2, which were detectable only in the presence of the functional allele of SS1 or SS2. Our results provided direct evidence that SS and yield traits in rice are controlled by complex signaling pathways and suggest further improvement of rice yield potential with enhanced and balanced SS relationships can be achieved by accurately manipulating allelic combinations at loci in the SS1 and SS2 mediated pathways. PMID:26162098

  3. Embedded algorithms for the SS-411 digital sun sensor

    NASA Astrophysics Data System (ADS)

    Enright, John; Sinclair, Doug; Li, Chris

    2009-05-01

    This paper discusses the evolution of the SS-411 series digital sun sensor. The earlier SS-256 and SS-330 models have proven themselves in orbit on low-cost satellite missions. The SS-411 represents a further hardware revision with enhanced robustness and improved attitude estimation performance. To complement the latest hardware improvements, researchers in the Space Avionics and Instrumentation Laboratory (SAIL) at Ryerson University in Toronto have developed advanced signal processing routines compatible with the SS-411. These routines significantly improve the accuracy of the sensor's estimation without increasing manufacturing complexity. With this advanced processing, the sensor maintains a 2-σ accuracy of 0.11° over the entire field-of-view.

  4. Tracheostomy tube - eating

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000464.htm Tracheostomy tube - eating To use the sharing features on ... when you swallow foods or liquids. Eating and Tracheostomy Tubes When you get your tracheostomy tube, or ...

  5. Condenser tube erosion-corrosion repairs using coatings

    SciTech Connect

    Lichtenstein, J.

    2000-02-01

    Condenser corrosion and erosion problems involving condenser (heat exchanger) water boxes, tubesheets, and tubes have been a maintenance problem for many years and continue to be so. Most often the materials of construction for surface condensers are galvanically incompatible. Usually the water box is carbon steel (CS) or cast iron, the tubesheet can be either CS or a copper-based alloy, and the tubes frequently are either a copper-based alloy, stainless steel (SS), or titanium. When erosion-corrosion problems arise and upgrading the tube alloy is not feasible or does not correct the problem there is a relatively inexpensive method of preventing or reducing the damage--thereby prolonging the life of the tube. Operators can coat the inlet end in the attacked region (normally 6 to 10 in. inside the tube) and the tubesheet. The coating material usually is a 100% solid epoxy or other high-solids, high-quality organic material.

  6. Tube-shape verifier

    NASA Technical Reports Server (NTRS)

    Anderson, A. N.; Christ, C. R.

    1980-01-01

    Inexpensive apparatus checks accuracy of bent tubes. Assortment of slotted angles and clamps is bolted down to flat aluminum plate outlining shape of standard tube bent to desired configuration. Newly bent tubes are then checked against this outline. Because parts are bolted down, tubes can be checked very rapidly without disturbing outline. One verifier per tube-bending machine can really speed up production in tube-bending shop.

  7. Heat exchanger tube mounts

    DOEpatents

    Wolowodiuk, W.; Anelli, J.; Dawson, B.E.

    1974-01-01

    A heat exchanger in which tubes are secured to a tube sheet by internal bore welding is described. The tubes may be moved into place in preparation for welding with comparatively little trouble. A number of segmented tube support plates are provided which allow a considerable portion of each of the tubes to be moved laterally after the end thereof has been positioned in preparation for internal bore welding to the tube sheet. (auth)

  8. A substitute for BOC modulation based on SS-CPM

    NASA Astrophysics Data System (ADS)

    Su, Chengeng; Guo, Shuren; Zhou, Hongwei

    2013-03-01

    CPM (continuous phase modulation) has been widely used in the field of satellite communication, which has high spectrum efficiency and constant envelope. This paper explores the applicability of CPM to satellite navigation. A SS-CPM (Spread-Spectrum CPM) modulation is investigated. The SS-CPM with tuned parameters can resemble the spectrum of Binary Offset Carrier (BOC) modulation and yields comparable performance in terms of tracking accuracy, multipath mitigation, anti-jamming, and compatibility. The BOC-like SS-CPM signal maintains the constant envelope at transmission and less out-band emission in radio determination satellite service (RDSS) band, which provides a reference modulation for COMPASS satellite navigation signal.

  9. EC Tube Fits

    SciTech Connect

    Kurita, C.H.; /Fermilab

    1987-03-03

    In the design of the EC, the beam tube, through which the beam line travels, can be found in the IH tube which is centrally located in the IH module. However, also between the beam tube and the IH tube lie both the vacuum and inner tubes of the vacuum and inner vessels. It is the vacuum between these vessels which provides insulation between the ambient beam tube and liquid argon in the cryostat. while the vacuum tube is supported along its length with the inner tube as best as possible, the inner tube will only be supported at the ends. The beam tube will also be end-supported, but it will be allowed to rest directly on the inner surface of the vacuum tube. It is required that the beam tube be able to slide in and out of the vacuum tube with relative ease in order that the EC's can be moved away from the CC when necessary (repair work, etc.). Although the frequency of such a move is not known, it is hoped to be low, and it would therefore be desirable, for cost reasons, to be able to use stock tubing for the vacuum and beam tubes instead of using specially machined tubing.

  10. 1. HISTORIC AMERICAN BUILDINGS SURVEY. S. Lucas, Photographer, 1934 SS. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. HISTORIC AMERICAN BUILDINGS SURVEY. S. Lucas, Photographer, 1934 SS. PETER & PAUL'S JESUIT CHURCH, DETROIT MICHIGAN - Sts. Peter & Paul's Jesuit Church, East Jefferson Avenue & Saint Antoine Street, Detroit, MI

  11. Human bulbar conjunctival hemodynamics in hemoglobin SS and SC disease

    PubMed Central

    Wanek, Justin; Gaynes, Bruce; Lim, Jennifer I.; Molokie, Robert; Shahidi, Mahnaz

    2014-01-01

    The known biophysical variations of hemoglobin (Hb) S and Hb C may result in hemodynamic differences between subjects with SS and SC disease. The purpose of this study was to measure and compare conjunctival hemodynamics between subjects with Hb SS and SC hemoglobinopathies. Image sequences of the conjunctival microcirculation were acquired in 9 healthy control subjects (Hb AA), 24 subjects with SC disease, and 18 subjects with SS disease, using a prototype imaging system. Diameter (D) and blood velocity (V) measurements were obtained in multiple venules of each subject. Data were categorized according to venule caliber by averaging V and D for venules with diameters less than (vessel size 1) or greater than (vessel size 2) 15 µm. V in vessel size 2 was significantly greater than V in vessel size 1 in the AA and SS groups (P ≥ 0.009), but not in the SC group (P = 0.1). V was significantly lower in the SC group as compared to the SS group (P = 0.03). In AA and SS groups, V correlated with D (P ≥ 0.005), but the correlation was not statistically significant in the SC group (P = 0.08). V was inversely correlated with hematocrit in the SS group for large vessels (P = 0.03); however, no significant correlation was found in the SC group (P ≥ 0.2). Quantitative assessment of conjunctival microvascular hemodynamics in SS and SC disease may advance understanding of sickle cell disease pathophysiology and thereby improve therapeutic interventions. PMID:23657867

  12. Bender/Coiler for Tubing

    NASA Technical Reports Server (NTRS)

    Stoltzfus, J. M.

    1983-01-01

    Easy-to-use tool makes coils of tubing. Tubing to be bend clamped with stop post. Die positioned snugly against tubing. Operator turns handle to slide die along tubing, pushing tubing into spiral groove on mandrel.

  13. The Spectral Components of SS 433

    NASA Astrophysics Data System (ADS)

    Gies, D. R.; McSwain, M. V.; Riddle, R. L.; Wang, Z.; Wiita, P. J.; Wingert, D. W.

    2002-02-01

    We present results from new optical and UV spectroscopy of the unusual binary system SS 433, and we discuss the relationship of the particular spectral components that we observe to the properties of the binary. These spectral components include1. The continuum spectrum, which we associate with flux from the super-Eddington accretion disk and the dense part of its wind. A far-UV spectrum from the Hubble Space Telescope Space Telescope Imaging Spectrograph made during the edge-on orientation of the disk places an upper limit on the temperature of an equivalent blackbody source (T<21,000 K for AV=7.8) when combined with near-UV and optical fluxes. The continuum source has an effective projected radius of approximately half the binary separation, so that the source may be larger than the Roche radius of the compact star.2. Hα moving components, which are formed far from the binary orbital plane in the relativistic jets. We confirm that these emission features appear as ``bullets'' at a fixed wavelength and may last for a few days. We present a contemporary radial velocity curve for the precessional motion of the jets that includes the nodding motion caused by tidal interaction with the optical star.3. Hα and He I ``stationary'' emission lines, which we suggest are formed in the disk wind in a volume larger than the dimensions of the binary. These lines vary on all timescales and sometimes appear as P Cygni lines. We suggest that their radial velocity curves (which show greatest redshift at inferior conjunction of the optical star) result from an evacuation of the disk wind surrounding the optical star (caused by physical blockage, heating, or colliding winds). We argue that the wake of this interaction region causes an extended eclipse of the X-ray source (as seen in Rossi X-Ray Timing Explorer All-Sky Monitor light curves).4. A weak ``stationary'' emission feature, which we identify as a C II λλ7231, 7236 blend that attains maximum radial velocity at the orbital

  14. Details of ssDNA annealing revealed by an HSV-1 ICP8–ssDNA binary complex

    PubMed Central

    Tolun, Gökhan; Makhov, Alexander M.; Ludtke, Steven J.; Griffith, Jack D.

    2013-01-01

    Infected cell protein 8 (ICP8) from herpes simplex virus 1 was first identified as a single-strand (ss) DNA-binding protein. It is essential for, and abundant during, viral replication. Studies in vitro have shown that ICP8 stimulates model replication reactions, catalyzes annealing of complementary ssDNAs and, in combination with UL12 exonuclease, will catalyze ssDNA annealing homologous recombination. DNA annealing and strand transfer occurs within large oligomeric filaments of ssDNA-bound ICP8. We present the first 3D reconstruction of a novel ICP8–ssDNA complex, which seems to be the basic unit of the DNA annealing machine. The reconstructed volume consists of two nonameric rings containing ssDNA stacked on top of each other, corresponding to a molecular weight of 2.3 MDa. Fitting of the ICP8 crystal structure suggests a mechanism for the annealing reaction catalyzed by ICP8, which is most likely a general mechanism for protein-driven DNA annealing. PMID:23605044

  15. Electrochemical Potential (ECP) of Clean Heated Fuel Cladding Material and Structural SS under BWR Operating Conditions

    SciTech Connect

    Pop, Mike G.; Bell, Merl; Kilian, Renate; Dorsch, Thomas; Christian, Mueller

    2007-07-01

    To preliminarily monitor the relative effect of advanced water chemistry measures on SS structural material and fuel cladding in BWR environments a number of experiments were performed using laboratory equipment (recirculation loop, autoclave with heated electrodes, reference electrodes, etc.). The simulation of the plant condition was done without impurities or crud deposit contribution (clean surfaces). Subsequent testing, performed during 2007 and not yet cleared for release, is considering the effect of combined complex BWR chemistries and crud deposition. The heated Zircaloy fuel cladding tubing was prepared to simulate heat transfer by internal heating at levels existing in BWR (70 W/cm{sup 2}). For comparison purposes additional type SS347 electrode and unheated zirconium was used. A platinum electrode was used to measure the redox potential of the electrolyte. A high temperature Ag/AgCl electrode was used as a reference electrode. The assembly was installed in a recirculation 1 liter autoclave. Present report presents corrosion potential measurements performed under the following BWR water chemistry conditions (at 288 deg. C fluid exit temperature, 86 bar with surface temperature of Zirconium hot finger at 296 deg. C) - normal (inert) water conditions, - hydrogen injection in three steps from 0.68 ppm to 1.6 ppm, - oxygen injection in three steps from 2.4 ppm to 10 ppm - -methanol 2 ppm and oxygen 2 ppm in a close loop (without methanol refreshing) (authors)

  16. Torsion Tests of Tubes

    NASA Technical Reports Server (NTRS)

    Stang, Ambrose H; Ramberg, Walter; Back, Goldie

    1937-01-01

    This report presents the results of tests of 63 chromium-molybdenum steel tubes and 102 17st aluminum-alloy tubes of various sizes and lengths made to study the dependence of the torsional strength on both the dimensions of the tube and the physical properties of the tube material. Three types of failure are found to be important for sizes of tubes frequently used in aircraft construction: (1) failure by plastic shear, in which the tube material reached its yield strength before the critical torque was reached; (2) failure by elastic two-lobe buckling, which depended only on the elastic properties of the tube material and the dimensions of the tube; and (3) failure by a combination of (1) and (2) that is, by buckling taking place after some yielding of the tube material.

  17. Performance test of a sorbent tube sampler with respect to analyte loss in collecting biogenic volatile organic compounds.

    PubMed

    Ullah, Md Ahsan; Kim, Ki-Hyun

    2015-01-01

    The superiority of thermal desorption-gas chromatography (TD-GC) applications is well known for the analysis of biogenic volatile organic compounds (BVOC). Despite the recognition of potential biases associated with sorptive loss reaction, the interaction of reactive BVOC with a sorbent tube (ST) sampler has not been sufficiently investigated. In this study, the extent of such a loss on a sampling device was studied against the sorbent holder materials by comparing stainless steel (SS; main target) and quartz (QZ; reference). To this end, three bed STs (Tenax TA, Carbopack B, and Carbopack X) were prepared using both holding materials (SS vs. QZ). The extent of BVOC loss was then tested for each material against two different phases (liquid and vapor) of ten monoterpenes. Accordingly, the soptive loss on the SS holder ranged from 10 % (vapor) to 20 % (liquid). If a vapor phase BVOC was forced to pass through an empty SS tube, the extent of their loss increased further in a range of 21.1 % (β-P) to 43.5 % (α-T). Likewise, similar loss rates (about 10 % reductions) were also observed when analyzing some environmental samples (pine needle) from the SS holder relative to QZ. Thus, a QZ tube is recommended over a SS tube to avoid sample loss in the collection of BVOC. PMID:25407426

  18. 1999 tubing guide

    SciTech Connect

    1999-06-01

    Petroleum Engineer International`s 1999 Tubing Guide contains performance and metallurgical data, as well as connection dimensions, on tubing from several companies. Parameters listed in each section were selected with the input of buyers and manufacturers of connections and tubing. Connections listings include: nominal tube OD, weight, tensile efficiency, sealing system, standard connection OD, special clearance OD, minimum ID and make-up loss. The grades section lists the tubing OD range, yield strength, tensile strength, hardness and whether the tubing is seamless or welded. An applications index specifies the downhole environments each grade can survive.

  19. Contribution à la modélisation du soudage TIG des tôles minces d'acier austénitique 304L par un modèle source bi-elliptique, avec confrontation expérimentale

    NASA Astrophysics Data System (ADS)

    Aissani, M.; Maza, H.; Belkessa, B.; Maamache, B.

    2005-05-01

    Ce travail contribue dans la modélisation du phénomène du soudage de l'acier inoxydable Austénitique 304L, afin d'étudier le comportement thermique d'un joint de soudure, obtenu par le procédé de soudage à l'arc électrique TIG (Tungsten-Inert-Gas). Le modèle simulant la source d'énergie de soudage, utilise une distribution surfacique Gaussienne du flux de chaleur provenant de l'arc électrique. La forme de cette source est supposée circulaire pour un premier cas et de forme bi-elliptique pour un second cas, tout en procédant à l'évaluation des champs et cycles thermiques à chaque instant, pour déterminer l'étendu des zones à risque, et l'effet de la vitesse de soudage sur ces dernières. Permettant ainsi de remonter par la suite, aux problèmes de contraintes résiduelles et déformations générées dans l'assemblage soudé. L'équation de chaleur régissant le problème est discrétisée par la méthode des volumes finis. Les calculs sont effectués en considérant que les propriétés physiques et thermiques ainsi que les conditions aux limites de convection et rayonnement, sont dépendante de la température. Pour évaluer la précision du modèle, une comparaison avec des mesures expérimentales de température d'un essai de soudage a été effectuée, les résultats indiquent un bon accord.

  20. Performance of DMFC with SS 316 bipolar/end plates

    NASA Astrophysics Data System (ADS)

    Padhy, Biswa R.; Reddy, Ramana G.

    This work mainly emphasizes the development of new materials and design for a bipolar/end plate in a direct methanol fuel cell (DMFC). According to the DOE requirements, preliminary studies show that SS 316 (Stainless Steel 316) is a suitable candidate. Several flow field designs were studied and a modified serpentine design was proposed. SS 316 end plates were fabricated with an intricate modified serpentine flow field design on it. The performance of a single stack DMFC with SS 316 end plates were studied with different operational parameters. A long-term test was carried out for 100 h with recycling the methanol and the contaminants in the MEA were characterized. The stack efficiency is found to be 51% and polarization losses are discussed. SS 316 with low permeability resulted in an increased pressure drop across the flow field, which increased the fuel cell performance. The use of SS 316 as bipolar plate material will reduce the machining cost as well as volume of the fuel cell stack.

  1. On the Nature of Compact Object in SS~433. An Observational Evidence of Black Hole Mass in SS 433

    NASA Astrophysics Data System (ADS)

    Titarchuk, Lev

    We present an analysis of X-ray spectral properties observed from black hole candidate (BHC) binary SS 433. We analyze RXTE data from this source, coordinated with Green Bank Interferometer/RATAN-600. We show that SS 433 demonstrates a X-ray spectral transition from low hard state to intermediate state (IS). We show that the X-ray broad-band energy spectra during all spectral states are well fit by a sum of so called "Bulk Motion Comptoniza-tion (BMC)" component and by two (broad and narrow) Gaussians for the continuum and line emissions respectively. In addition to these spectral model components we also find a strong feature of "blackbody-like (BB)" bump which color temperature is in the range of 4-5 keV in 24 IS spectra during radio outburst decay in SS 433. Our observational results on the "high temperature BB" bump leads us to support the presence of gravitationally redshifted annihila-tion lines in this source. We also established the photon index saturation at about 2.3 in index vs mass accretion correlation. This index-mass accretion correlation allows us to evaluate the low limit of black hole (BH) mass of compact object in SS 433, greater than 2 solar masses, using the scaling method using BHC GX 339-4 as a reference source. Our estimate of BH mass in SS 433 is consistent with the recent BH mass measurement by Hillwig Gies who find that BH mass about 4.3 solar masses. It is the smallest BH mass up to now found among all BHC sources where BH masses have been estimated so far. Moreover, the index saturation effect versus mass accretion rate revealed in SS 433, like in a number of other BHCs, is the strongest observational evidence of the presence of BH in SS 433.

  2. Neural Tube Defects

    MedlinePlus

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, ...

  3. Tracheostomy tube - speaking

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000465.htm Tracheostomy tube - speaking To use the sharing features on ... are even speaking devices that can help you. Tracheostomy Tubes and Speaking Air passing through vocal cords ( ...

  4. Tracheostomy tube - speaking

    MedlinePlus

    ... key part of communicating with people. Having a tracheostomy tube can change your ability to talk and ... you can learn how to speak with a tracheostomy tube. It just takes practice. There are even ...

  5. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  6. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  7. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  8. 78 FR 23981 - Proposed Collection; Comment Request for Form SS-8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... Internal Revenue Service Proposed Collection; Comment Request for Form SS-8 AGENCY: Internal Revenue...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form SS-8, Determination of Worker... Employment Taxes and Income Tax Withholding. OMB Number: 1545-0004. Form Number: SS-8. Abstract: Form SS-8...

  9. 75 FR 10017 - Proposed Collection; Comment Request for Form SS-8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... Internal Revenue Service Proposed Collection; Comment Request for Form SS-8 AGENCY: Internal Revenue...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form SS-8, Determination of Worker... Employment Taxes and Income Tax Withholding. OMB Number: 1545-0004. Form Number: SS-8. Abstract: Form SS-8...

  10. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  11. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  12. Microhole Tubing Bending Report

    DOE Data Explorer

    Oglesby, Ken

    2012-01-01

    A downhole tubing bending study was made and is reported herein. IT contains a report and 2 excel spreadsheets to calculate tubing bending and to estimate contact points of the tubing to the drilled hole wall (creating a new support point).

  13. e-VLBI observations of SS 433 in outburst

    NASA Astrophysics Data System (ADS)

    Tudose, V.; Paragi, Z.; Trushkin, S.; Soleri, P.; Fender, R.; Garrett, M.; Spencer, R.; Rushton, A.; Burgess, P.; Kunert-Bajraszewska, M.; Pazderski, E.; Borkowski, K.; Hammargren, R.; Lindqvist, M.; Maccaferri, G.

    2008-11-01

    We have observed the X-ray binary SS 433 on November 6, 2008 between 13:48-18:35 UT at 5 GHz with the European VLBI Network (EVN) using the e-VLBI technique. The radio telescopes participating in the experiment were: Medicina, Onsala 25m, Torun, Jodrell Bank MkII and Cambridge. The X-ray binary SS 433 is in outburst. Trushkin & Nizhelskij (ATel #1819) reported a major flare already active during the RATAN-600 observations in the 1-22 GHz band on 2008 October 28.

  14. The spotted contact binary SS ARIETIS - Spectroscopy and infrared photometry

    NASA Astrophysics Data System (ADS)

    Rainger, P. P.; Bell, S. A.; Hilditch, R. W.

    1992-02-01

    The first infrared photometry for the W-UMa system SS Ari is presented. An analysis based on medium-resolution spectroscopy presented here shows that SS Ari is a W-type system with a mass ratio of 0.33. It seems certain that the asymmetry in the published light curves and those obtained for this study can be explained by the effect of spots on one or possibly both components of the system. The precise location, size and temperature of these spots require the use of Doppler Imaging techniques in conjunction with high-quality multiband photometry.

  15. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into...

  16. Telescoping tube assembly

    NASA Technical Reports Server (NTRS)

    Sturm, Albert J. (Inventor); Marrinan, Thomas E. (Inventor)

    1995-01-01

    An extensible and retractable telescoping tube positions test devices that inspect large stationary objects. The tube has three dimensional adjustment capabilities and is vertically suspended from a frame. The tube sections are independently supported with each section comprising U-shaped housing secured to a thicker support plate. Guide mechanisms preferably mounted only to the thicker plates guide each tube section parallel to a reference axis with improved accuracy so that the position of the remote end of the telescoping tube is precisely known.

  17. REACTOR COOLANT TUBE SEAL

    DOEpatents

    Morris, W.J.

    1958-12-01

    A plle-flattenlng control element and a fluid seal therefore to permit movement of the element into a liquld contnining region of a neutronlc reactor are described. The device consists of flattened, thin-walled aluminum tubing contalnlng a uniform mixture of thermal neutron absorbing material, and a number of soft rubber closures for the process tubes, having silts capable of passing the flattened elements therethrough, but effectively sealing the process tubes against fluld leaknge by compression of the rubber. The flattened tubing is sufficiently flexible to enable it to conform to the configuratlon of the annular spacing surrounding the fuel elements ln the process tubes.

  18. Corrosion guard tubing nipple

    SciTech Connect

    Guy, W.E.

    1988-09-27

    This patent describes the process of placing a string of tubing in an oil field well; a. the string of tubing when placed extending from the surface of the earth to an oil bearing formation far below the surface, b. the string made from i. a plurality of tubing sections, ii. each section having external threads on each end, and iii. cuffs with internal threads coupling the tubing sections together, c. each of the tubing sections having i. an axis, ii. a wall thickness, and iii. a corrosion resistant coating on its inside bore; wherein the improved method comprises: d. placing a section of tubing into the well with a cuff attached to the upper end at the surface of the earth, e. dropping a corrosion resistant nipple into the cuff, f. the nipple being loose in the cuff, g. attaching an additional section of tubing onto the cuff, and h. screwing the additional section tightly to the cuff.

  19. Heat tube device

    NASA Technical Reports Server (NTRS)

    Khattar, Mukesh K. (Inventor)

    1990-01-01

    The present invention discloses a heat tube device through which a working fluid can be circulated to transfer heat to air in a conventional air conditioning system. The heat tube device is disposable about a conventional cooling coil of the air conditioning system and includes a plurality of substantially U-shaped tubes connected to a support structure. The support structure includes members for allowing the heat tube device to be readily positioned about the cooling coil. An actuatable adjustment device is connected to the U-shaped tubes for allowing, upon actuation thereof, for the heat tubes to be simultaneously rotated relative to the cooling coil for allowing the heat transfer from the heat tube device to air in the air conditioning system to be selectively varied.

  20. Intercostal drainage tube or intracardiac drainage tube?

    PubMed Central

    Anitha, N.; Kamath, S. Ganesh; Khymdeit, Edison; Prabhu, Manjunath

    2016-01-01

    Although insertion of chest drain tubes is a common medical practice, there are risks associated with this procedure, especially when inexperienced physicians perform it. Wrong insertion of the tube has been known to cause morbidity and occasional mortality. We report a case where the left ventricle was accidentally punctured leading to near-exsanguination. This report is to highlight the need for experienced physicians to supervise the procedure and train the younger physician in the safe performance of the procedure. PMID:27397467

  1. NARSTO EPA SS ST LOUIS AIR CHEM PM MET DATA

    Atmospheric Science Data Center

    2014-05-07

    NARSTO EPA SS ST LOUIS AIR CHEM PM MET DATA Project Title:  NARSTO ... Amount Surface Pressure Solar Radiation Surface Air Temperature Particulates Trace Metals Order Data:  ... Data Guide Documents:  St Louis Air Chem Guide St Louis Final Report  (PDF) St Louis QA ...

  2. NARSTO EPA SS NEW YORK AIR CHEM PM MET DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS NEW YORK AIR CHEM PM MET DATA Project Title:  NARSTO ... Thermooptical Transmission Location:  New York Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  New York Air Chem Guide CPM Summary Report  (PDF) ...

  3. RPA homologs and ssDNA processing during meiotic recombination.

    PubMed

    Ribeiro, Jonathan; Abby, Emilie; Livera, Gabriel; Martini, Emmanuelle

    2016-06-01

    Meiotic homologous recombination is a specialized process that involves homologous chromosome pairing and strand exchange to guarantee proper chromosome segregation and genetic diversity. The formation and repair of DNA double-strand breaks (DSBs) during meiotic recombination differs from those during mitotic recombination in that the homologous chromosome rather than the sister chromatid is the preferred repair template. The processing of single-stranded DNA (ssDNA) formed on intermediate recombination structures is central to driving the specific outcomes of DSB repair during meiosis. Replication protein A (RPA) is the main ssDNA-binding protein complex involved in DNA metabolism. However, the existence of RPA orthologs in plants and the recent discovery of meiosis specific with OB domains (MEIOB), a widely conserved meiosis-specific RPA1 paralog, strongly suggest that multiple RPA complexes evolved and specialized to subdivide their roles during DNA metabolism. Here we review ssDNA formation and maturation during mitotic and meiotic recombination underlying the meiotic specific features. We describe and discuss the existence and properties of MEIOB and multiple RPA subunits in plants and highlight how they can provide meiosis-specific fates to ssDNA processing during homologous recombination. Understanding the functions of these RPA homologs and how they interact with the canonical RPA subunits is of major interest in the fields of meiosis and DNA repair. PMID:26520106

  4. KInNeSS: a modular framework for computational neuroscience.

    PubMed

    Versace, Massimiliano; Ames, Heather; Léveillé, Jasmin; Fortenberry, Bret; Gorchetchnikov, Anatoli

    2008-01-01

    Making use of very detailed neurophysiological, anatomical, and behavioral data to build biologically-realistic computational models of animal behavior is often a difficult task. Until recently, many software packages have tried to resolve this mismatched granularity with different approaches. This paper presents KInNeSS, the KDE Integrated NeuroSimulation Software environment, as an alternative solution to bridge the gap between data and model behavior. This open source neural simulation software package provides an expandable framework incorporating features such as ease of use, scalability, an XML based schema, and multiple levels of granularity within a modern object oriented programming design. KInNeSS is best suited to simulate networks of hundreds to thousands of branched multi-compartmental neurons with biophysical properties such as membrane potential, voltage-gated and ligand-gated channels, the presence of gap junctions or ionic diffusion, neuromodulation channel gating, the mechanism for habituative or depressive synapses, axonal delays, and synaptic plasticity. KInNeSS outputs include compartment membrane voltage, spikes, local-field potentials, and current source densities, as well as visualization of the behavior of a simulated agent. An explanation of the modeling philosophy and plug-in development is also presented. Further development of KInNeSS is ongoing with the ultimate goal of creating a modular framework that will help researchers across different disciplines to effectively collaborate using a modern neural simulation platform. PMID:18695948

  5. The Symbiotic System SS73 17 seen with Suzaku

    NASA Technical Reports Server (NTRS)

    Smith, Randall K.; Mushotzky, Richard; Kallman, Tim; Tueller, Jack; Mukai, Koji; Markwardt, Craig

    2007-01-01

    We observed with Suzaku the symbiotic star SS73 17, motivated by the discovery by the INTEGRAL satellite and the Swift BAT survey that it emits hard X-rays. Our observations showed a highly-absorbed X-ray spectrum with NH > loz3 emp2, equivalent to Av > 26, although the source has B magnitude 11.3 and is also bright in UV. The source also shows strong, narrow iron lines including fluorescent Fe K as well as Fe xxv and Fe XXVI. The X-ray spectrum can be fit with a thermal model including an absorption component that partially covers the source. Most of the equivalent width of the iron fluorescent line in this model can be explained as a combination of reprocessing in a dense absorber plus reflection off a white dwarf surface, but it is likely that the continuum is partially seen in reflection as well. Unlike other symbiotic systems that show hard X-ray emission (CH Cyg, RT Cru, T CrB, GX1+4), SS73 17 is not known to have shown nova-like optical variability, X-ray flashes, or pulsations, and has always shown faint soft X-ray emission. As a result, although it is likely a white dwarf, the nature of the compact object in SS73 17 is still uncertain. SS73 17 is probably an extreme example of the recently discovered and relatively small class of hard X-ray emitting symbiotic systems.

  6. NARSTO EPA SS HOUSTON TEXAQS2000 CAMS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 CAMS DATA Project Title:  NARSTO ... TEOM Fluorescence Spectroscopy Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston TexAQS2000 CAMS Guide Houston Project Plan  (PDF) ...

  7. NARSTO EPA SS HOUSTON TEXAQS2000 PM SIZE MASS

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 PM SIZE MASS Project Title:  NARSTO ... Aerosol Collector Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston TexAQS2000 PM Size Guide Houston Project Plan  (PDF) ...

  8. NARSTO EPA SS HOUSTON TEXAQS2000 PM FTIR

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 PM FTIR Project Title:  NARSTO ... Transform Infrared Spectrometer) Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston TexAQS2000 PM Guide Houston Project Plan  (PDF) ...

  9. NARSTO EPA SS HOUSTON NO3 SO4 C DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON NO3 SO4 C DATA Project Title:  NARSTO ... IR Carbon Dioxide Analyzer Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston NO3 SO4 Guide Houston Project Plan  (PDF) ...

  10. NARSTO EPA SS HOUSTON NH3 HNO3 DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON NH3 HNO3 DATA Project Title:  NARSTO ... Ion Chromatograph Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston HN3 HNO3 Guide Houston Project Plan  (PDF) ...

  11. Outburst from SS 433 observed with BOOTES-2/COLORES

    NASA Astrophysics Data System (ADS)

    Caballero-Garcia, M. D.; Castro-Tirado, A.; Jelinek, M.; et al.

    2014-08-01

    In light of the recent extreme outburst of SS 433 (ATELs #6347, #6355) and follow-up by SWIFT (ATEL #6364) the 0.6m TELMA robotic telescope at the BOOTES-2 (+COLORES) astronomical station in Malaga (Spain), obtained optical 4000-9000 A spectra starting at 2014-08-01 and ending at 2014-08-07.

  12. 10 K high frequency pulse tube cryocooler with precooling

    NASA Astrophysics Data System (ADS)

    Liu, Sixue; Chen, Liubiao; Wu, Xianlin; Zhou, Yuan; Wang, Junjie

    2016-07-01

    A high frequency pulse tube cryocooler with precooling (HPTCP) has been developed and tested to meet the requirement of weak magnetic signals measurement, and the performance characteristics are presented in this article. The HPTCP is a two-stage pulse tube cryocooler with the precooling-stage replaced by liquid nitrogen. Two regenerators completely filled with stainless steel (SS) meshes are used in the cooler. Together with cold inertance tubes and cold gas reservoir, a cold double-inlet configuration is used to control the phase relationship of the HPTCP. The experimental result shows that the cold double-inlet configuration has improved the performance of the cooler obviously. The effects of operation parameters on the performance of the cooler are also studied. With a precooling temperature of 78.5 K, the maximum refrigeration capacity is 0.26 W at 15 K and 0.92 W at 20 K when the input electric power are 174 W and 248 W respectively, and the minimum no-load temperature obtained is 10.3 K, which is a new record on refrigeration temperature for high frequency pulse tube cryocooler reported with SS completely used as regenerative matrix.

  13. Pulse Tube Refrigerator

    NASA Astrophysics Data System (ADS)

    Matsubara, Yoichi

    The pulse tube refrigerator is one of the regenerative cycle refrigerators such as Stirling cycle or Gifford-McMahon cycle which gives the cooling temperature below 150 K down to liquid helium temperature. In 1963, W. E. Gifford invented a simple refrigeration cycle which is composed of compressor, regenerator and simple tube named as pulse tube which gives a similar function of the expander in Stirling or Gifford-McMahon cycle. The thermodynamically performance of this pulse tube refrigerator is inferior to that of other regenerative cycles. In 1984, however, Mikulin and coworkers made a significant advance in pulse tube configuration called as orifice pulse tube. After this, several modifications of the pulse tube hot end configuration have been developed. With those modifications, the thermodynamic performance of the pulse tube refrigerator became the same order to that of Stirling and Gifford-McMahon refrigerator. This article reviews the brief history of the pulse tube refrigerator development in the view point of its thermodynamically efficiency. Simplified theories of the energy flow in the pulse tube have also been described.

  14. Experimental atomic scale investigation of irradiation effects in CW 316SS and UFG-CW 316SS

    NASA Astrophysics Data System (ADS)

    Pareige, P.; Etienne, A.; Radiguet, B.

    2009-06-01

    Materials of the core internals of pressurized water reactor (austenitic stainless steels) are subject to neutron irradiation. To understand the ageing mechanisms associated with irradiation and propose life predictions of components or develop new materials, irradiation damage needs to be experimentally investigated. Atomic scale investigation of a neutron-irradiated CW316 SS with the laser pulsed atom probe gives a detailed description of the solute segregation in the austenitic grains. In order to understand the mechanism of solute segregation detected in the neutron-irradiated materials, ion irradiations were performed. These latest irradiations were realized on a CW 316SS as well as on a nanostructured CW 316SS. The study of irradiation effects in a nanograin material allows first, to easily analyse grain boundary segregation and second, to test the behaviour under irradiation of a new nanostructured material. The three aspects of this atomic scale investigation (neutron irradiation effect, model ion irradiation, new nanostructured CW 316 SS) are tackled in this paper.

  15. 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.

  16. Collapse of flux tubes

    NASA Astrophysics Data System (ADS)

    Wilets, L.; Puff, R. D.

    1995-01-01

    The dynamics of an idealized, infinite, MIT-type flux tube is followed in time as the interior evolves from a pure gluon field to a q¯q plasma. We work in color U(1). q¯q pair formation is evaluated according to the Schwinger mechanism using the results of Brink and Pavel. The motion of the quarks toward the tube end caps is calculated by a Boltzmann equation including collisions. The tube undergoes damped radial oscillations until the electric field settles down to zero. The electric field stabilizes the tube against pinch instabilities; when the field vanishes, the tube disintegrates into mesons. There is only one free parameter in the problem, namely the initial flux tube radius, to which the results are very sensitive. Among various quantities calculated is the mean energy of the emitted pions.

  17. Ruggedized electronographic tube development

    NASA Technical Reports Server (NTRS)

    Nevin, S.

    1981-01-01

    Because of their glass components and lack of far ultraviolet sensitivity, currently available Spectracons are not suited for rocket launch. Technology developed for second generation image tubes and for magnetically focused image tubes can be applied to improve the optical and mechanical properties of these magnetically focused electronographic tubes whose 40 kilovolt signal electrons exit a 4-micrometer thick mica window and penetrate a photographic recording emulsion.

  18. Tube-welder aids

    NASA Technical Reports Server (NTRS)

    Weaver, J. F.

    1980-01-01

    Simple tools assist in setting up and welding tubes. Welder aids can be easily made to fit given tube diameter. Finished set can be used repeatedly to fix electrode-to-weld gap and mark sleeve and joint positions. Tools are readily made in tube-manufacturing plants and pay for themselves in short time in reduced labor costs and quality control: Conventional measurements are too slow for mass production and are prone to errors.

  19. Conduction cooled tube supports

    DOEpatents

    Worley, Arthur C.; Becht, IV, Charles

    1984-01-01

    In boilers, process tubes are suspended by means of support studs that are in thermal contact with and attached to the metal roof casing of the boiler and the upper bend portions of the process tubes. The support studs are sufficiently short that when the boiler is in use, the support studs are cooled by conduction of heat to the process tubes and the roof casing thereby maintaining the temperature of the stud so that it does not exceed 1400.degree. F.

  20. TUBE SPLITTING APPARATUS

    DOEpatents

    Frantz, C.E.; Cawley, W.E.

    1961-05-01

    A tool is described for cutting a coolant tube adapted to contain fuel elements to enable the tube to be removed from a graphite moderator mass. The tool splits the tube longitudinally into halves and curls the longitudinal edges of the halves inwardly so that they occupy less space and can be moved radially inwardly away from the walls of the hole in the graphite for easy removal from the graphite.

  1. Imaging Transition Zone Thickness Beneath South America from SS Precursors

    NASA Astrophysics Data System (ADS)

    Schmerr, N.; Garnero, E.

    2006-12-01

    We image detailed upper mantle discontinuity structure beneath a number of geologically active regions, including the South American subduction zone, the Scotia plate subduction zone, and several volcanic hotspots (e.g., the Galapagos Islands), in a region ~10,000 km by 10,000 km wide, spanning 70° S to 20° N and 20° W to 110° W. Precursors to the seismic phase SS are analyzed, which form as a result of underside reflections off seismic discontinuities beneath the midpoint of the SS path and are highly sensitive to discontinuity depth and sharpness. Our SS dataset consists of over 15,000 high-quality transverse component broadband displacement seismograms collected from the Incorporated Research Institutions for Seismology (IRIS), the Canadian National Seismic Network (CNSN), as well as data from EarthScope seismic stations, and from the Canadian Northwest Experiment (CANOE) temporary broadband array deployment. This dataset densely samples several regions in our study area and significantly improves the sampling for this area compared to previous precursor studies. Data with common central SS bouncepoints are stacked to enhance precursory phases. Solution discontinuity structure depends on a number of factors, including dominant seismic period, crustal correction, signal-to-noise ratio threshold, and tomography model used for mantle heterogeneity correction. We exclude precursor data predicted to interfere with other seismic phases, such as topside reflections (e.g., s670sS), which have been demonstrated to contaminate final stacks. Solution transition zone thickness is at least 20 km thicker than global average estimates of 242 km along the northwestern portion of the South American subduction complex (Peru, Ecuador, and Columbia); this thickening extends 1000-1500 km to the east beneath the continent, but does not appear to continue south of -20° latitude along the convergent margin. A minimum of 10 km of thickening is imaged to the west of the Scotia

  2. Sapphire tube pressure vessel

    SciTech Connect

    Outwater, J.O.

    2000-05-23

    A pressure vessel is provided for observing corrosive fluids at high temperatures and pressures. A transparent Teflon bag contains the corrosive fluid and provides an inert barrier. The Teflon bag is placed within a sapphire tube, which forms a pressure boundary. The tube is received within a pipe including a viewing window. The combination of the Teflon bag, sapphire tube and pipe provides a strong and inert pressure vessel. In an alternative embodiment, tie rods connect together compression fittings at opposite ends of the sapphire tube.

  3. Sapphire tube pressure vessel

    DOEpatents

    Outwater, John O.

    2000-01-01

    A pressure vessel is provided for observing corrosive fluids at high temperatures and pressures. A transparent Teflon bag contains the corrosive fluid and provides an inert barrier. The Teflon bag is placed within a sapphire tube, which forms a pressure boundary. The tube is received within a pipe including a viewing window. The combination of the Teflon bag, sapphire tube and pipe provides a strong and inert pressure vessel. In an alternative embodiment, tie rods connect together compression fittings at opposite ends of the sapphire tube.

  4. Flared tube attachment fitting

    NASA Technical Reports Server (NTRS)

    Alkire, I. D.; King, J. P., Jr.

    1980-01-01

    Tubes can be flared first, then attached to valves and other flow line components, with new fitting that can be disassembled and reused. Installed fitting can be disassembled so parts can be inspected. It can be salvaged and reused without damaging flared tube; tube can be coated, tempered, or otherwise treated after it has been flared, rather than before, as was previously required. Fitting consists of threaded male portion with conical seating surface, hexagonal nut with hole larger than other diameter of flared end of tube, and split ferrule.

  5. 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.

  6. Composite Pulse Tube

    NASA Technical Reports Server (NTRS)

    Martin, Jerry L.; Cloyd, Jason H.

    2007-01-01

    A modification of the design of the pulse tube in a pulse-tube cryocooler reduces axial thermal conductance while preserving radial thermal conductance. It is desirable to minimize axial thermal conductance in the pulse-tube wall to minimize leakage of heat between the warm and cold ends of the pulse tube. At the same time, it is desirable to maximize radial thermal conductance at the cold end of the pulse tube to ensure adequate thermal contact between (1) a heat exchanger in the form of a stack of copper screens inside the pulse tube at the cold end and (2) the remainder of the cold tip, which is the object to which the heat load is applied and from which heat must be removed. The modified design yields a low-heat-leak pulse tube that can be easily integrated with a cold tip. A typical pulse tube of prior design is either a thin-walled metal tube or a metal tube with a nonmetallic lining. It is desirable that the outer surface of a pulse tube be cylindrical (in contradistinction to tapered) to simplify the design of a regenerator that is also part of the cryocooler. Under some conditions, it is desirable to taper the inner surface of the pulse tube to reduce acoustic streaming. The combination of a cylindrical outer surface and a tapered inner surface can lead to unacceptably large axial conduction if the pulse tube is made entirely of metal. Making the pulse-tube wall of a nonmetallic, lowthermal- conductivity material would not solve the problem because the wall would not afford the needed thermal contact for the stack of screens in the cold end. The modified design calls for fabricating the pulse tube in two parts: a longer, nonmetallic part that is tapered on the inside and cylindrical on the outside and a shorter, metallic part that is cylindrical on both the inside and the outside. The nonmetallic part can be made from G-10 fiberglass-reinforced epoxy or other low-thermal-conductivity, cryogenically compatible material. The metallic part must have high

  7. 316L stainless steel tubes corrosion influenced by SRB in sea water

    SciTech Connect

    Yoffe, P.

    1997-08-01

    A tube made from SS316L was attacked by stagnated sea water. The typical onion form of the pits were obscured in welded and unwelded sectors of the tube. Iron sulfides FeS{sub 1{minus}x} and FeS{sub 2} (in pyrite form) were observed on effected surface of the tube, in addition to iron chloride and oxide/hydroxide. Theoretical investigation was based on cluster model of alloy and thermodynamic/kinetic characterization of possible reactions. It was concluded that microbially influenced sulfidizing played an accelerating role in the failure that exhibited the typical characteristics for stagnated sea water effect to chromium-nickel stainless steel.

  8. Fluence dependence of deuterium retention in oxidized SS-316

    NASA Astrophysics Data System (ADS)

    Oya, Yasuhisa; Suzuki, Sachiko; Matsuyama, Masao; Hayashi, Takumi; Yamanishi, Toshihiko; Asakura, Yamato; Okuno, Kenji

    2011-10-01

    The ion fluence dependence of deuterium retention in SS-316 during oxidation at a temperature of 673 K was studied to evaluate the dynamics of deuterium retention in the oxide layer of SS-316. The correlation between the chemical state of stainless steel and deuterium retention was evaluated using XPS and TDS. It was found that the major deuterium desorption temperatures were located at around 660 K and 935 K, which correspond to the desorption of deuterium trapped as hydroxide. The deuterium retention increased with increasing deuterium ion fluence, since the deuterium retention as hydroxide increased significantly. However, retention saturated at an ion fluence of ˜2.5 × 10 21 D + m -2. The XPS result showed that FeOOD was formed on the surface, although pure Fe also remained in the oxide layer. These facts indicate the nature of the oxide layer have a key role in deuterium trapping behavior.

  9. Validation of Robotic Surgery Simulator (RoSS).

    PubMed

    Kesavadas, Thenkurussi; Stegemann, Andrew; Sathyaseelan, Gughan; Chowriappa, Ashirwad; Srimathveeravalli, Govindarajan; Seixas-Mikelus, Stéfanie; Chandrasekhar, Rameella; Wilding, Gregory; Guru, Khurshid

    2011-01-01

    Recent growth of daVinci Robotic Surgical System as a minimally invasive surgery tool has led to a call for better training of future surgeons. In this paper, a new virtual reality simulator, called RoSS is presented. Initial results from two studies - face and content validity, are very encouraging. 90% of the cohort of expert robotic surgeons felt that the simulator was excellent or somewhat close to the touch and feel of the daVinci console. Content validity of the simulator received 90% approval in some cases. These studies demonstrate that RoSS has the potential of becoming an important training tool for the daVinci surgical robot. PMID:21335803

  10. Nuclear processes in the jets of SS 433

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

    1984-01-01

    The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS 433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg-asterisk and (16)O-asterisk in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS 433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations.

  11. Nuclear processes in the jets of SS433

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

    1984-01-01

    The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg* and (16)O* in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations.

  12. Steam generator tube failures

    SciTech Connect

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  13. Corrosion Performance of Stainless Steels in a Simulated Launch Environment

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina; Vinje, Rubiela D.; MacDowell, Louis

    2004-01-01

    At the Kennedy Space Center, NASA relies on stainless steel (SS) tubing to supply the gases and fluids required to launch the Space Shuttle. 300 series SS tubing has been used for decades but the highly corrosive environment at the launch pad has proven to be detrimental to these alloys. An upgrade with higher alloy content materials has become necessary in order to provide a safer and long lasting launch facility. In the effort to find the most suitable material to replace the existing AISI 304L SS ([iNS S30403) and AISI 316L SS (UNS S31603) shuttle tubing, a study involving atmospheric exposure at the corrosion test site near the launch pads and electrochemical measurements is being conducted. This paper presents the results of an investigation in which stainless steels of the 300 series, 304L, 316L, and AISI 317L SS (UNS S31703) as well as highly alloyed stainless steels 254-SMO (UNS S32154), AL-6XN (N08367) and AL29-4C ([iNS S44735) were evaluated using direct current (DC) electrochemical techniques under conditions designed to simulate those found at the Space Shuttle Launch pad. The electrochemical results were compared to the atmospheric exposure data and evaluated for their ability to predict the long-term corrosion performance of the alloys.

  14. Hollow conical jet models for SS 433 - A paradigm lost?

    NASA Technical Reports Server (NTRS)

    Kochanek, Christopher S.; Hawley, John F.

    1990-01-01

    A precessing jet such as that in SS 433 may be approximated as an axisymmetric flow, if the precession time is short by comparison to the propagation time. A series of simulations has been conducted for precessing jets using an axisymmetric finite-difference hydrodynamics code. Examinations are made of hollow cylindrical jets, which lack the complication of a growing interior volume, and conical jets, which model the behavior of a precessing jet propagating on the surface of its precession cone.

  15. Elastic-plastic analysis of the SS-3 tensile specimen

    SciTech Connect

    Majumdar, S.

    1998-09-01

    Tensile tests of most irradiated specimens of vanadium alloys are conducted using the miniature SS-3 specimen which is not ASTM approved. Detailed elastic-plastic finite element analysis of the specimen was conducted to show that, as long as the ultimate to yield strength ratio is less than or equal to 1.25 (which is satisfied by many irradiated materials), the stress-plastic strain curve obtained by using such a specimen is representative of the true material behavior.

  16. Revisiting the HST Fine Guidance Sensor Parallax of SS Cygni

    NASA Astrophysics Data System (ADS)

    Harrison, Thomas E.; McArthur, Barbara

    2016-01-01

    Recently, our results for the HST FGS parallax of SS Cyg (Harrison et al. 2000) have been called into question due to a recent radio parallax for this object (Miller-Jones et al. 2013). We have re-analyzed the data for our FGS program on SS Cyg and derive a revised parallax of 7.3 +/- 0.2 mas (137 pc). This parallax is 17% larger than that originally published. We discuss the new analysis effort, and the reasons for the change in our result. We believe we have identified why the radio parallax (8.77 mas) disagrees with the FGS results: We find that if we allow for a roll of two degrees in the HST coordinate system, we obtain the discrepant VLBA radio parallax. It is impossible, however, for the error in the roll of HST to be more than a few tenths of a degree, or else the FGS would not lock-on to the program targets. This roll leads to the large, and erroneous VLBA parallax for SS Cyg. We note that the radio parallax for the black hole system V404 Cyg (Miller-Jones et al. 2009) is also much larger than the spectroscopic parallax of its secondary star. In addition, we closely examine the attempt by Nelan & Bond (2013) to reconcile the FGS data set with the radio result. We identify what we believe to be significant issues with their analysis. Finally, we present a quantitative abundance analysis for SS Cyg, RU Peg, and GK Per derived from moderate resolution K-band spectroscopy. We find severe carbon deficiencies (10 to 20% of the solar value) in the secondary stars of all three objects. We describe the Python program "kmoog" which generates synthetic spectra, and autonomously compares them to observational data.

  17. Computer-aided planning of SS/TDMA network operation

    NASA Astrophysics Data System (ADS)

    Mizuike, Takeshi; Nguyen, Lan N.; Ito, Yasuhiko; Maeda, Eijiro

    1991-01-01

    A computer-aided approach to the planning of SS/TDMA network operation is proposed. SS/TDMA is a sophisticated satellite communication network based on an onboard switch matrix, whose operation planning is formulated as a large-scale scheduling problem. An overall planning and scheduling model is presented to deal with practical SS/TDMA systems, such as a two-frequency channel network and nondisjoint beam coverage. For systematic planning suitable for a computer-aided approach, the entire scheduling process is divided into several steps, for each of which an efficient mathematical model is proposed. A linear programming model is used for distribution of traffic on a beam-to-beam basis and the generated switching sequence is further refined by a model using the traveling salesman problem. Burst scheduling is carried out by the Bin packing algorithm and scheduling models for practical networks allowing transponder hopping and multidestination bursts. An algorithm called enhanced rescheduling is presented to further improve the scheduling capability of the existing methods. The performance of the proposed methods is demonstrated by simulation results.

  18. THE Be STAR SPECTRA (BeSS) DATABASE

    SciTech Connect

    Neiner, C.; De Batz, B.; Cochard, F.; Floquet, M.; Mekkas, A.; Desnoux, V.

    2011-11-15

    Be stars vary on many timescales, from hours to decades. A long time base of observations to analyze certain phenomena in these stars is therefore necessary. Collecting all existing and future Be star spectra into one database has thus emerged as an important tool for the Be star community. Moreover, for statistical studies, it is useful to have centralized information on all known Be stars via an up-to-date catalog. These two goals are what the Be Star Spectra (BeSS, http://basebe.obspm.fr) database proposes to achieve. The database contains an as-complete-as-possible catalog of known Be stars with stellar parameters, as well as spectra of Be stars from all origins (any wavelength, any epoch, any resolution, etc.). It currently contains over 54,000 spectra of more than 600 different Be stars among the {approx}2000 Be stars in the catalog. A user can access and query this database to retrieve information on Be stars or spectra. Registered members can also upload spectra to enrich the database. Spectra obtained by professional as well as amateur astronomers are individually validated in terms of format and science before being included in BeSS. In this paper, we present the database itself as well as examples of the use of BeSS data in terms of statistics and the study of individual stars.

  19. LoCuSS: Testing hydrostatic equilibrium in galaxy clusters

    NASA Astrophysics Data System (ADS)

    Smith, G. P.; Mazzotta, P.; Okabe, N.; Ziparo, F.; Mulroy, S. L.; Babul, A.; Finoguenov, A.; McCarthy, I. G.; Lieu, M.; Bahé, Y. M.; Bourdin, H.; Evrard, A. E.; Futamase, T.; Haines, C. P.; Jauzac, M.; Marrone, D. P.; Martino, R.; May, P. E.; Taylor, J. E.; Umetsu, K.

    2016-02-01

    We test the assumption of hydrostatic equilibrium in an X-ray luminosity selected sample of 50 galaxy clusters at 0.15 < z < 0.3 from the Local Cluster Substructure Survey (LoCuSS). Our weak-lensing measurements of M500 control systematic biases to sub-4 per cent, and our hydrostatic measurements of the same achieve excellent agreement between XMM-Newton and Chandra. The mean ratio of X-ray to lensing mass for these 50 clusters is β_X= 0.95± 0.05, and for the 44 clusters also detected by Planck, the mean ratio of Planck mass estimate to LoCuSS lensing mass is β_P= 0.95± 0.04. Based on a careful like-for-like analysis, we find that LoCuSS, the Canadian Cluster Comparison Project, and Weighing the Giants agree on β_P ≃ 0.9-0.95 at 0.15 < z < 0.3. This small level of hydrostatic bias disagrees at ˜5σ with the level required to reconcile Planck cosmology results from the cosmic microwave background and galaxy cluster counts.

  20. The astrophysical torus. 2: Light curves of SS 433

    NASA Astrophysics Data System (ADS)

    Sanbuichi, Kiyotaka; Fukue, Jun

    1993-10-01

    Using the mass function obtained by D'Odorico et al. (1991), we recalculate the theoretical light curves of SS 433 in the primary eclipse and confront them with observations. We assume that in SS 433 there exists a geometrically thick torus around a compact object, and that the primary eclipse is an eclipse of the torus by a companion of an early-type star. The main parameters are the shape of the tori, the size of the tori, and the binary mass ratio. We obtain light curves for several combinations of parameters. The light curves for sufficiently thick tori are deep at the mid-eclipse and preferable, while those for geometrically thin tori are shallow. The duration of eclipse for a large torus is long and beneficial, while that for a small torus is short. Finally, Delta m at mid-eclipse for a thick torus around a neutron star becomes approximately 0.6 and suitable, whereas for thick tori around a black hole it is approximately 0.3. Hence, under the new mass function, geometrically thick and wide tori around a neutron star can well reproduce the observed light curves of SS 433.

  1. Tritium uptake by SS316 and its decontamination

    NASA Astrophysics Data System (ADS)

    Torikai, Y.; Penzhorn, R.-D.; Matsuyama, M.; Watanabe, K.

    2004-08-01

    As-received and highly polished SS316 specimens were loaded with HT at 473-573 K. The uptake by polished samples was found to be up to five times that of as-received ones, when loading was performed immediately after polishing. This disparity vanished when polished specimens were subjected to a prolonged exposure to air prior to loading. The tritium loss from tritium-loaded SS316 specimens was examined by chemical etching and by thermal release in a flow system using various carrier gases at several temperatures. While at moderate temperatures the type of carrier has an impact on the tritium release rate, at higher ones this effect disappears. Moisture in the carrier gas has little influence on the loss rate of bulk tritium. Etching depth profiles of specimens previously heat-treated in the presence of air or Ar + H 2 and of untreated specimens are given. Evidence for chronic tritium liberation from SS316 at 298 K is provided.

  2. Welding Tubes In Place

    NASA Technical Reports Server (NTRS)

    Meredith, R.

    1984-01-01

    Special welding equipment joins metal tubes that carry pressurized cyrogenic fluids. Equipment small enough to be used in confined spaces in which such tubes often mounted. Welded joints lighter in weight and more leak-proof than joints made with mechanical fittings.

  3. Pyrotechnic Tubing Connector

    NASA Technical Reports Server (NTRS)

    Graves, Thomas J.; Yang, Robert A.

    1988-01-01

    Tool forms mechanical seal at joint without levers or hydraulic apparatus. Proposed tool intended for use in outer space used on Earth by heavily garbed workers to join tubing in difficult environments. Called Pyrotool, used with Lokring (or equivalent) fittings. Piston slides in cylinder when pushed by gas from detonating pyrotechnic charge. Impulse of piston compresses fittings, sealing around butting ends of tubes.

  4. 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.

  5. Fallopian Tube Catheterization

    PubMed Central

    Thurmond, Amy Suzanne

    2013-01-01

    Fallopian tube catheterization is used for treatment of infertility caused by proximal tubal occlusion, and has replaced surgical treatment for this condition. More recently, fallopian tube catheterization has been used for tubal sterilization. Interventional radiologists tested numerous methods for tubal occlusion using the rabbit as an animal model. As a result, a tubal device has recently been Food and Drug Administration approved for permanent sterilization using hysteroscopic guidance; it can also be placed fluoroscopically by fallopian tube catheterization as an “off-label” procedure. This is a 5-year continuation and update on a procedure that has been done by interventional radiologists for 25 years; history of the development of fallopian tube catheterization in women has been published in detail in this journal. Highlighted in this article will be description of the basic components needed for fallopian tube catheterization. PMID:24436565

  6. SS 383: A NEW S-TYPE YELLOW SYMBIOTIC STAR?

    SciTech Connect

    Baella, N. O.; Pereira, C. B.; Miranda, L. F.

    2013-11-01

    Symbiotic stars are key objects in understanding the formation and evolution of interacting binary systems, and are probably the progenitors of Type Ia supernovae. However, the number of known symbiotic stars is much lower than predicted. We aim to search for new symbiotic stars, with particular emphasis on the S-type yellow symbiotic stars, in order to determine their total population, evolutionary timescales, and physical properties. The Two Micron All Sky Survey (2MASS) (J – H) versus (H – K {sub s}) color-color diagram has been previously used to identify new symbiotic star candidates and show that yellow symbiotics are located in a particular region of that diagram. Candidate symbiotic stars are selected on the basis of their locus in the 2MASS (J – H) versus (H – K {sub s}) diagram and the presence of Hα line emission in the Stephenson and Sanduleak Hα survey. This diagram separates S-type yellow symbiotic stars from the rest of the S-type symbiotic stars, allowing us to select candidate yellow symbiotics. To establish the true nature of the candidates, intermediate-resolution spectroscopy is obtained. We have identified the Hα emission line source SS 383 as an S-type yellow symbiotic candidate by its position in the 2MASS color-color diagram. The optical spectrum of SS 383 shows Balmer, He I, He II, and [O III] emission lines, in combination with TiO absorption bands that confirm its symbiotic nature. The derived electron density (≅10{sup 8-9} cm{sup –3}), He I emission line intensity ratios, and position in the [O III] λ5007/Hβ versus [O III] λ4363/Hγ diagram indicate that SS 383 is an S-type symbiotic star, with a probable spectral type of K7-M0 deduced for its cool component based on TiO indices. The spectral type and the position of SS 383 (corrected for reddening) in the 2MASS color-color diagram strongly suggest that SS 383 is an S-type yellow symbiotic. Our result points out that the 2MASS color-color diagram is a powerful tool in

  7. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  8. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  9. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  10. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  11. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  12. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  13. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  14. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  15. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  16. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  17. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  18. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  19. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  20. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  1. Robotic Tube-Gap Inspector

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L.; Gutow, David A.; Maslakowski, John E.

    1993-01-01

    Robotic vision system measures small gaps between nearly parallel tubes. Robot-held video camera examines closely spaced tubes while computer determines gaps between tubes. Video monitor simultaneously displays data on gaps.

  2. What Are Neural Tube Defects?

    MedlinePlus

    ... NICHD Research Information Clinical Trials Resources and Publications Neural Tube Defects (NTDs): Condition Information Skip sharing on ... media links Share this: Page Content What are neural tube defects? Neural (pronounced NOOR-uhl ) tube defects ...

  3. Holder for Straightening Bent Tubes

    NASA Technical Reports Server (NTRS)

    Turner, A. R.; Polzien, E. D.

    1985-01-01

    One-piece holder restrains bent metal tube against further bending during straightening operation. Holder consists of handle 16 in. (41 cm) long welded to short, strong tube that fits around tube to be straightened.

  4. Eustachian Tube Function.

    PubMed

    Ars, Bernard; Dirckx, Joris

    2016-10-01

    The fibrocartilaginous eustachian tube is part of a system of contiguous organs including the nose, palate, rhinopharynx, and middle ear cleft. The middle ear cleft consists of the tympanic cavity, which includes the bony eustachian tube (protympanum) and the mastoid gas cells system. The tympanic cavity and mastoid gas cells are interconnected and allow gaseous exchange and pressure regulation. The fibrocartilaginous eustachian tube is a complex organ consisting of a dynamic conduit with its mucosa, cartilage, surrounding soft tissue, peritubal muscles (ie, tensor and levator veli palatine, salpingopharyngeus and tensor tympani), and superior bony support (the sphenoid sulcus). PMID:27468632

  5. PCI-SS: MISO dynamic nonlinear protein secondary structure prediction

    PubMed Central

    Green, James R; Korenberg, Michael J; Aboul-Magd, Mohammed O

    2009-01-01

    Background Since the function of a protein is largely dictated by its three dimensional configuration, determining a protein's structure is of fundamental importance to biology. Here we report on a novel approach to determining the one dimensional secondary structure of proteins (distinguishing α-helices, β-strands, and non-regular structures) from primary sequence data which makes use of Parallel Cascade Identification (PCI), a powerful technique from the field of nonlinear system identification. Results Using PSI-BLAST divergent evolutionary profiles as input data, dynamic nonlinear systems are built through a black-box approach to model the process of protein folding. Genetic algorithms (GAs) are applied in order to optimize the architectural parameters of the PCI models. The three-state prediction problem is broken down into a combination of three binary sub-problems and protein structure classifiers are built using 2 layers of PCI classifiers. Careful construction of the optimization, training, and test datasets ensures that no homology exists between any training and testing data. A detailed comparison between PCI and 9 contemporary methods is provided over a set of 125 new protein chains guaranteed to be dissimilar to all training data. Unlike other secondary structure prediction methods, here a web service is developed to provide both human- and machine-readable interfaces to PCI-based protein secondary structure prediction. This server, called PCI-SS, is available at . In addition to a dynamic PHP-generated web interface for humans, a Simple Object Access Protocol (SOAP) interface is added to permit invocation of the PCI-SS service remotely. This machine-readable interface facilitates incorporation of PCI-SS into multi-faceted systems biology analysis pipelines requiring protein secondary structure information, and greatly simplifies high-throughput analyses. XML is used to represent the input protein sequence data and also to encode the resulting

  6. EUVE photometry of SS Cygni: Dwarf nova outbursts and oscillations

    SciTech Connect

    Mauche, C.W.

    1995-05-15

    The authors present EUVE Deep Survey photometry and AAVSO optical measurements of the 1993 August and 1994 June/July outbursts of the dwarf nova SS Cygni. The EUV and optical light curves are used to illustrate the different response of the accretion disk to outbursts which begin at the inner edge and propagate outward, and those which begin at the outer edge and propagate inward. Furthermore, the authors describe the properties of the quasi-coherent 7--9 s sinusoidal oscillations in the EUV flux detected during the rise and plateau stages of these outbursts.

  7. Osler usque ad mare: the SS William Osler

    PubMed Central

    Bryan, C S; Fransiszyn, M

    1999-01-01

    William Osler's connections with the sea included a strong family history of seafaring, his own transatlantic crossings (of which there were at least 32) and the occasional use of nautical imagery in his inspirational writings. An unusual Oslerian connection with the sea emerged after his death in the form of a World War II Liberty ship. Through the SS William Osler and its sister ships, Osler was symbolically reunited with colleagues associated with the early days of the Johns Hopkins Hospital. The William Osler circumnavigated the globe in 1943 without engaging the enemy. She was then converted into an army hospital ship and renamed the USHS Wisteria. PMID:10530306

  8. Building with Tubes.

    ERIC Educational Resources Information Center

    D'Eugenio, Terrance, Ed.

    Text and illustrations show how to assemble furniture and toys out of cardboard tubes and sheets. Basic directions are provided, and the tools and materials necessary to the assembly of specific items are described. (MLF)

  9. Magnetic flux tube tunneling

    SciTech Connect

    Dahlburg, R.B.; Antiochos, S.K.; Norton, D.

    1997-08-01

    We present numerical simulations of the collision and subsequent interaction of {ital orthogonal} magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can {open_quotes}tunnel{close_quotes} through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch {gt}1, and the Lundquist number must be somewhat large, {ge}2880. An examination of magnetic field lines suggests that tunneling is due to a double-reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections, and {open_quotes}pass{close_quotes} through each other. The implications of these results for solar and space plasmas are discussed. {copyright} {ital 1997} {ital The American Physical Society}

  10. Ear tube insertion - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100045.htm Ear tube insertion - series—Normal anatomy To use the ... 4 Overview The eardrum (tympanic membrane) separates the ear canal from the middle ear. Update Date 8/ ...

  11. PEG tube insertion -- discharge

    MedlinePlus

    ... Search Search MedlinePlus GO GO About MedlinePlus Site ... To use the sharing features on this page, please enable JavaScript. A PEG (percutaneous endoscopic gastrostomy) feeding tube insertion is the placement of ...

  12. Chest tube insertion

    MedlinePlus

    ... leaks from inside the lung into the chest ( pneumothorax ) Fluid buildup in the chest (called a pleural ... on the reason a chest tube is inserted. Pneumothorax usually improves, but sometimes needs minimally invasive surgery. ...

  13. Eustachian Tube Dysfunction

    MedlinePlus

    ... flying (because of altitude changes). Riding in elevators, driving through mountains or diving may also make your symptoms worse. Causes & Risk Factors What causes eustachian tube dysfunction? The most common ...

  14. Tube Alinement for Machining

    NASA Technical Reports Server (NTRS)

    Garcia, J.

    1984-01-01

    Tool with stepped shoulders alines tubes for machining in preparation for welding. Alinement with machine tool axis accurate to within 5 mils (0.13mm) and completed much faster than visual setup by machinist.

  15. Snorkeling and Jones tubes

    PubMed Central

    Lam, Lewis Y. W.; Weatherhead, Robert G.

    2015-01-01

    Summary We report a case of tympanic membrane rupture during snorkeling in a 17-year-old young man who had previously undergone bilateral Jones tubes placed for epiphora. To our knowledge, this phenomenon has not been previously reported.

  16. Integrated structure vacuum tube

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Kerwin, W. J. (Inventor)

    1976-01-01

    High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Anode and grid members are formed using thin films of refractory metal. Electron flow in the tubes is between grid elements from cathode to anode as in a conventional three-dimensional tube.

  17. Magnetic flux tube tunneling

    NASA Astrophysics Data System (ADS)

    Dahlburg, R. B.; Antiochos, S. K.; Norton, D.

    1997-08-01

    We present numerical simulations of the collision and subsequent interaction of orthogonal magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can ``tunnel'' through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch >>1, and the Lundquist number must be somewhat large, >=2880. An examination of magnetic field lines suggests that tunneling is due to a double-reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections, and ``pass'' through each other. The implications of these results for solar and space plasmas are discussed.

  18. Tubing crimping pliers

    DOEpatents

    Lindholm, G.T.

    1981-02-27

    The disclosure relates to pliers and more particularly to pliers for crimping two or more pieces of copper tubing together prior to their being permanently joined by brazing, soldering or the like. A die containing spring-loaded pins rotates within a cammed ring in the head of the pliers. As the die rotates, the pins force a crimp on tubing held within the pliers.

  19. ss3sim: An R Package for Fisheries Stock Assessment Simulation with Stock Synthesis

    PubMed Central

    Anderson, Sean C.; Monnahan, Cole C.; Johnson, Kelli F.; Ono, Kotaro; Valero, Juan L.

    2014-01-01

    Simulation testing is an important approach to evaluating fishery stock assessment methods. In the last decade, the fisheries stock assessment modeling framework Stock Synthesis (SS3) has become widely used around the world. However, there lacks a generalized and scriptable framework for SS3 simulation testing. Here, we introduce ss3sim, an R package that facilitates reproducible, flexible, and rapid end-to-end simulation testing with SS3. ss3sim requires an existing SS3 model configuration along with plain-text control files describing alternative population dynamics, fishery properties, sampling scenarios, and assessment approaches. ss3sim then generates an underlying ‘truth’ from a specified operating model, samples from that truth, modifies and runs an estimation model, and synthesizes the results. The simulations can be run in parallel, reducing runtime, and the source code is free to be modified under an open-source MIT license. ss3sim is designed to explore structural differences between the underlying truth and assumptions of an estimation model, or between multiple estimation model configurations. For example, ss3sim can be used to answer questions about model misspecification, retrospective patterns, and the relative importance of different types of fisheries data. We demonstrate the software with an example, discuss how ss3sim complements other simulation software, and outline specific research questions that ss3sim could address. PMID:24699270

  20. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section 868.5800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy...

  1. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a surgical opening of the trachea to facilitate ventilation to the lungs. The cuff may be a separate...

  2. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a surgical opening of the trachea to facilitate ventilation to the lungs. The cuff may be a separate...

  3. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a surgical opening of the trachea to facilitate ventilation to the lungs. The cuff may be a separate...

  4. Biocompatibility of blood tubings.

    PubMed

    Branger, B; Garreau, M; Baudin, G; Gris, J C

    1990-10-01

    We studied hemocompatibility of various blood tubings with C3a anaphylatoxin measurement and comparative electron scanning microscopy. The following tubing materials were tested: polyvinylchloride (PVC) plasticised with phthalate (PVC), pvc plasticised with phthalate coextruded with polyurethane (PIV), and two phthalate-free lines: pvc plasticised with trimellitate coextruded with polyurethane (TRI) and pvc plasticised with LT 360 (LTP). Results of C3a generation rate showed a significant activation by all blood tubings, with a reduced rate with PIV when compared to all others. Electron scanning microscopy showed marked alterations of PIV surface on tubings stored for 6 months. Protein deposits on internal surfaces after dialysis were similar whatever tubing material was tested, but adhesive cell number was greater with TRI when compared to PVC and LTP. Hemocompatibility is unchanged with phthalate-free tubings when compared to phthalate plasticised ones. In contrast with phthalate plasticised PVC there is no beneficial effect of polyurethane coextrusion with trimellitate plasticised PVC in regard to C3a generation. PMID:2254048

  5. Aeronautical tubes and pipes

    NASA Astrophysics Data System (ADS)

    Beauclair, N.

    1984-12-01

    The main and subcomponent French suppliers of aircraft tubes and pipes are discussed, and the state of the industry is analyzed. Quality control is essential for tubes with regard to their i.d. and metallurgical compositions. French regulations do not allow welded seam tubes in hydraulic circuits unless no other form is available, and then rustproofed steel must be installed. The actual low level of orders for any run of tubes dictates that the product is only one of several among the manufacturers' line. Automation, both in NDT and quality control, assures that the tubes meet specifications. A total of 10 French companies participate in the industry, serving both civil and military needs, with some companies specializing only in titanium, steel, or aluminum materials. Concerns wishing to enter the market must upgrade their equipment to meet the higher aeronautical specifications and be prepared to furnish tubes and pipes that serve both functional and structural purposes simultaneously. Additionally, pipe-bending machines must also perform to tight specifications. Pipes can range from 0.2 mm exterior diameter to 40 mm, with wall thicknesses from 0.02 mm to 3 mm. A chart containing a list of manufacturers and their respective specifications and characteristics is presented, and a downtrend in production with reduction of personnel is noted.

  6. Dynamic tube/support interaction in heat exchanger tubes

    SciTech Connect

    Chen, S.S.

    1991-01-01

    The supports for heat exchanger tubes are usually plates with drilled holes; other types of supports also have been used. To facilitate manufacture and to allow for thermal expansion of the tubes, small clearances are used between tubes and tube supports. The dynamics of tube/support interaction in heat exchangers is fairly complicated. Understanding tube dynamics and its effects is important for heat exchangers. This paper summarizes the current state of the art on this subject and to identify future research needs. Specifically, the following topics are discussed: dynamics of loosely supported tubes, tube/support gap dynamics, tube response in flow, tube damage and wear, design considerations, and future research needs. 55 refs., 1 fig.

  7. Acousto-microfluidics for screening of ssDNA aptamer

    PubMed Central

    Park, Jee-Woong; Lee, Su Jin; Ren, Shuo; Lee, Sangwook; Kim, Soyoun; Laurell, Thomas

    2016-01-01

    We demonstrate a new screening method for obtaining a prostate-specific antigen (PSA) binding aptamer based on an acoustofluidic separation (acoustophoreis) technique. Since acoustophoresis provides simultaneous washing and separation in a continuous flow mode, we efficiently obtained a PSA binding aptamer that shows high affinity without any additional washing step, which is necessary in other screening methods. In addition, next-generation sequencing (NGS) was applied to accelerate the identification of the screened ssDNA pool, improving the selecting process of the aptamer candidate based on the frequency ranking of the sequences. After the 8th round of the acoustophoretic systematic evolution of ligands by exponential enrichment (SELEX) and following sequence analysis with NGS, 7 PSA binding ssDNA aptamer-candidates were obtained and characterized with surface plasmon resonance (SPR) for affinity and specificity. As a result of the new SELEX method with PSA as the model target protein, the best PSA binding aptamer showed specific binding to PSA with a dissociation constant (Kd) of 0.7 nM. PMID:27272884

  8. Acousto-microfluidics for screening of ssDNA aptamer.

    PubMed

    Park, Jee-Woong; Lee, Su Jin; Ren, Shuo; Lee, Sangwook; Kim, Soyoun; Laurell, Thomas

    2016-01-01

    We demonstrate a new screening method for obtaining a prostate-specific antigen (PSA) binding aptamer based on an acoustofluidic separation (acoustophoreis) technique. Since acoustophoresis provides simultaneous washing and separation in a continuous flow mode, we efficiently obtained a PSA binding aptamer that shows high affinity without any additional washing step, which is necessary in other screening methods. In addition, next-generation sequencing (NGS) was applied to accelerate the identification of the screened ssDNA pool, improving the selecting process of the aptamer candidate based on the frequency ranking of the sequences. After the 8(th) round of the acoustophoretic systematic evolution of ligands by exponential enrichment (SELEX) and following sequence analysis with NGS, 7 PSA binding ssDNA aptamer-candidates were obtained and characterized with surface plasmon resonance (SPR) for affinity and specificity. As a result of the new SELEX method with PSA as the model target protein, the best PSA binding aptamer showed specific binding to PSA with a dissociation constant (Kd) of 0.7 nM. PMID:27272884

  9. XTE Proposal #20102--"SS 433's High Energy Spectrum"

    NASA Technical Reports Server (NTRS)

    Band, David L.; Blanco, P.; Rothschild, R.; Kawai, N.; Kotani, T.; Oka, T.; Wagner, R. M.; Hjellming, R.; Rupen, M.; Brinkmann, W.

    1999-01-01

    We observed the jet-producing compact binary system SS 433 with RXTE during three multiwavelength campaigns, the first in conjunction with ASCA observations, the second simultaneous with a VLA-VLBA-MERLIN campaign, and the third associated with a Nobeyama millimeter-band campaign. All these campaigns included optical observations. Occurring at different jet precession and binary phases, the observations also monitored the system during a radio flare. The data provide SS 433's X-ray spectrum over more than an energy decade, and track the spectral variations as the X-ray source was partially eclipsed. The continuum can be modeled as a power law with an exponential cutoff, which can be detected to approximately 50 keV. Strong line emission is evident in the 5-10 keV range which can be modeled as a broad line whose energy is precession independent and a narrow line whose energy does vary with jet precession phase; this line model is clearly an over simplification since the PCA does not have sufficient energy resolution to detect the lines ASCA observed. The eclipses are deeper at high energy and at jet precession phases when the jets are more inclined towards and away from us. A large radio flare occurred between two sets of X-ray monitoring observations; an X-ray observation at the peak of the flare found a softer spectrum with a flux approximately 1/3 that of the quiescent level.

  10. Capillary electrophoresis of small ssDNA molecules

    NASA Astrophysics Data System (ADS)

    Kopecka, Katerina; Slater, Gary W.; Drouin, Guy

    2004-03-01

    Recently, the electrophoretic separation of small ssDNA fragments (bellow 250 bases) has attracted a lot of attention because of applications related to Single Nucleotide Polymorphisms. In order to optimize these systems, we require a better understanding of DNA migration behavior in this size range. While the reptation model provides an excellent understanding of the dynamics of long DNA fragments in gel electrophoresis, the properties of small DNA fragments has not been studied extensively yet. At least three theoretical formulas have been proposed to explain the mobility of short ssDNA molecules in this regime. Specifically, the Ogston regime was introduced for small molecules having radii-of-gyration comparable to or smaller than the pore size of the sieving matrix. We introduce these three different formulas and discuss how their free parameters are related to actual physical parameters. We then test these formulas with new data obtained by capillary electrophoresis in our laboratory using poly(dimethylacrylamide) sieving matrices. Our results show that all three formulas provide decent fits, and that their fitting parameters are consistent with one another. This is the first step towards the development of a systematic approach to optimizing sequencing systems for this size range.

  11. Reversibly shielded DNA polyplexes based on bioreducible PDMAEMA-SS-PEG-SS-PDMAEMA triblock copolymers mediate markedly enhanced nonviral gene transfection.

    PubMed

    Zhu, Caihong; Zheng, Meng; Meng, Fenghua; Mickler, Frauke Martina; Ruthardt, Nadia; Zhu, Xiulin; Zhong, Zhiyuan

    2012-03-12

    Reversibly shielded DNA polyplexes based on bioreducible poly(dimethylaminoethyl methacrylate)-SS-poly(ethylene glycol)-SS-poly(dimethylaminoethyl methacrylate) (PDMAEMA-SS-PEG-SS-PDMAEMA) triblock copolymers were designed, prepared and investigated for in vitro gene transfection. Two PDMAEMA-SS-PEG-SS-PDMAEMA copolymers with controlled compositions, 6.6-6-6.6 and 13-6-13 kDa, were obtained by reversible addition-fragmentation chain transfer (RAFT) polymerization of dimethylaminoethyl methacrylate (DMAEMA) using CPADN-SS-PEG-SS-CPADN (CPADN: 4-cyanopentanoic acid dithionaphthalenoate; PEG: 6 kDa) as a macro-RAFT agent. Like their nonreducible PDMAEMA-PEG-PDMAEMA analogues, PDMAEMA-SS-PEG-SS-PDMAEMA triblock copolymers could effectively condense DNA into small particles with average diameters less than 120 nm and close to neutral zeta potentials (0 ∼ +6 mV) at and above an N/P ratio of 3/1. The resulting polyplexes showed excellent colloidal stability against 150 mM NaCl, which contrasts with polyplexes of 20 kDa PDMAEMA homopolymer. In the presence of 10 mM dithiothreitol (DTT), however, polyplexes of PDMAEMA-SS-PEG-SS-PDMAEMA were rapidly deshielded and unpacked, as revealed by significant increase of positive surface charges as well as increase of particle sizes to over 1000 nm. Release of DNA in response to 10 mM DTT was further confirmed by gel retardation assays. These polyplexes, either stably or reversibly shielded, revealed a low cytotoxicity (over 80% cell viability) at and below an N/P ratio of 12/1. Notably, in vitro transfection studies showed that reversibly shielded polyplexes afforded up to 28 times higher transfection efficacy as compared to stably shielded control under otherwise the same conditions. Confocal laser scanning microscope (CLSM) studies revealed that reversibly shielded polyplexes efficiently delivered and released pDNA into the perinuclei region as well as nuclei of COS-7 cells. Hence, reduction-sensitive reversibly shielded DNA

  12. A pulsed eddy current probe for inspection of support plates from within Alloy-800 steam generator tubes

    SciTech Connect

    Krause, T. W.; Babbar, V. K.; Underhill, P. R.

    2014-02-18

    Support plate degradation and fouling in nuclear steam generators (SGs) can lead to SG tube corrosion and loss of efficiency. Inspection and monitoring of these conditions can be integrated with preventive maintenance programs, thereby advancing station-life management processes. A prototype pulsed eddy current (PEC) probe, targeting inspection issues associated with SG tubes in SS410 tube support plate structures, has been developed using commercial finite element (FE) software. FE modeling was used to identify appropriate driver and pickup coil configurations for optimum sensitivity to changes in gap and offset for Alloy-800 SG tubes passing through 25 mm thick SS410 support plates. Experimental measurements using a probe that was manufactured based on the modeled configuration, were used to confirm the sensitivity of differential PEC signals to changes in relative position of the tube within the tube support plate holes. Models investigated the effect of shift and tilt of tube with respect to hole centers. Near hole centers and for small shifts, modeled signal amplitudes from the differentially connected coil pairs were observed to change linearly with tube shift. This was in agreement with experimentally measured TEC coil response. The work paves the way for development of a system targeting the inspection and evaluation of support plate structures in steam generators.

  13. A pulsed eddy current probe for inspection of support plates from within Alloy-800 steam generator tubes

    NASA Astrophysics Data System (ADS)

    Krause, T. W.; Babbar, V. K.; Underhill, P. R.

    2014-02-01

    Support plate degradation and fouling in nuclear steam generators (SGs) can lead to SG tube corrosion and loss of efficiency. Inspection and monitoring of these conditions can be integrated with preventive maintenance programs, thereby advancing station-life management processes. A prototype pulsed eddy current (PEC) probe, targeting inspection issues associated with SG tubes in SS410 tube support plate structures, has been developed using commercial finite element (FE) software. FE modeling was used to identify appropriate driver and pickup coil configurations for optimum sensitivity to changes in gap and offset for Alloy-800 SG tubes passing through 25 mm thick SS410 support plates. Experimental measurements using a probe that was manufactured based on the modeled configuration, were used to confirm the sensitivity of differential PEC signals to changes in relative position of the tube within the tube support plate holes. Models investigated the effect of shift and tilt of tube with respect to hole centers. Near hole centers and for small shifts, modeled signal amplitudes from the differentially connected coil pairs were observed to change linearly with tube shift. This was in agreement with experimentally measured TEC coil response. The work paves the way for development of a system targeting the inspection and evaluation of support plate structures in steam generators.

  14. Tool Extracts Smooth, Fragile Tubes

    NASA Technical Reports Server (NTRS)

    Sanders, Fred G.

    1988-01-01

    When laterally compressible tube too slippery to pull, simple tool does job. Consists of three linked sections of steel tube with sticky rubber on inside and handles on outside. Hinged sections encircle tube to be pulled. User pulls on handles to extract tube.

  15. Experiments on plasma immersion ion implantation inside conducting tubes embedded in an external magnetic field

    NASA Astrophysics Data System (ADS)

    Pillaca, E. J. D. M.; Ueda, M.; Reuther, H.; Pichon, L.; Lepienski, C. M.

    2015-12-01

    Tubes of stainless steel (SS) embedded in external magnetic field were used to study the effects of plasma immersion ion implantation (PIII) as a function of their diameter. The study was complemented with and without a grounded auxiliary electrode (AE) placed at the axis of the tube. During the discharge tests in tubes of larger diameter (D = 11 cm), with and without AE, nitrogen gas breakdown was established inside the tube at pressures near 2.0 × 10-2 mbar. Under the same operation conditions, stable plasmas with similar PIII current densities were obtained for both arrangements. Reducing the diameter of the tube (D = 1.5 cm) turned the plasma unstable and made it inappropriate for ion implantation. This situation was solved by supplying gas at higher pressure or using higher magnetic field, without the presence of an AE. Under these conditions, nitrogen PIII treatments of these small diameter tubes were performed but gave not the best implantation results yet. Our results have also shown higher ion implantation current density (16 mA/cm2) in tube of intermediate diameter (D = 4 cm) using AE, compared to largest diameter tube used. In this case, a thick nitrogen layer of about 9 μm was obtained in the SS sample placed inside the tube. As a consequence of this, its structural and mechanical properties were enhanced. These results are attributed to the thermal diffusion promoted by ions hitting the inner wall in a large number due to the presence of the AE and the magnetic field.

  16. KiSS-1 expression in oral squamous cell carcinoma and its prognostic significance.

    PubMed

    Shin, Wui-Jung; Cho, Young-Ah; Kang, Kyung-Rim; Kim, Ji-Hoon; Hong, Seong-Doo; Lee, Jae-Il; Hong, Sam-Pyo; Yoon, Hye-Jung

    2016-04-01

    Downregulated expression of KiSS-1 has been correlated with tumor progression, metastasis, and patient prognosis in various human malignancies. However, there is no information regarding the expression of KiSS-1 in oral squamous cell carcinoma (OSCC). Our aims were to examine KiSS-1 expression in OSCC tissue samples and cell lines and to determine its prognostic significance. KiSS-1 expression was significantly lower in lymph node (LN) metastases than in primary tumor tissues. Five of six OSCC cell lines showed absence or relatively low expression of KiSS-1. Correlations between KiSS-1 expression and clinicopathological parameters were statistically assessed. There were significant correlations between KiSS-1 expression and LN metastasis (p = 0.007), TNM stage (p = 0.024), and local recurrence (p = 0.012). In the Kaplan-Meier survival analysis, negative KiSS-1 expression significantly correlated with poorer overall survival (OS) and disease-free survival (DFS) (p = 0.000 and 0.000, respectively). Multivariate analysis using Cox regression modeling revealed that KiSS-1 expression was an independent prognostic factor for both OS and DFS (p = 0.001 and 0.000, respectively). Our findings suggested that KiSS-1 downregulation may play a role in tumor progression and metastasis of OSCC and may be a reliable biomarker for predicting clinical outcome in OSCC. PMID:26809635

  17. Sensitivity of the magnetization curves of different austenitic stainless tube and pipe steels to mechanical fatigue

    NASA Astrophysics Data System (ADS)

    Niffenegger, M.; Leber, H. J.

    2008-07-01

    In meta-stable austenitic stainless steels, fatigue is accompanied by a partial strain-induced transformation of paramagnetic austenite to ferromagnetic martensite [G.B. Olsen, M. Cohen, Kinetics of strain induced martensite nucleation, Metall. Trans. 6 (1975) 791-795]. The associated changes of magnetic properties as the eddy current impedance, magnetic permeability or the remanence field may serve as an indication for the degree of fatigue and therefore the remaining lifetime of a component, even though the exact causal relationship between martensite formation and fatigue is not fully understood. However, measuring these properties by magnetic methods may be limited by the low affinity for strain-induced martensite formation. Thus other methods have to be found which are able to detect very small changes of ferromagnetic contents. With this aim the influence of cyclic strain loading on the magnetization curves of the austenitic stainless tube and pipe steels TP 321, 347, 304L and 316L is analysed in the present paper. The measured characteristic magnetic properties, which are the saturation magnetization, residual magnetization, coercive field and the field dependent permeability (AC-magnetization), are sensitive to fatigue and the corresponding material changes (martensitic transformation). In particular, the AC-magnetization was found to be very sensitive to small changes of the amount of strain induced martensite and therefore also to the degree of fatigue. Hence we conclude that applying magnetic minor loops are promising for the non-destructive evaluation of fatigue in austenitic stainless steel, even if a very small amount of strain induced martensite is formed.

  18. Neural tube defects.

    PubMed

    Greene, Nicholas D E; Copp, Andrew J

    2014-01-01

    Neural tube defects (NTDs), including spina bifida and anencephaly, are severe birth defects of the central nervous system that originate during embryonic development when the neural tube fails to close completely. Human NTDs are multifactorial, with contributions from both genetic and environmental factors. The genetic basis is not yet well understood, but several nongenetic risk factors have been identified as have possibilities for prevention by maternal folic acid supplementation. Mechanisms underlying neural tube closure and NTDs may be informed by experimental models, which have revealed numerous genes whose abnormal function causes NTDs and have provided details of critical cellular and morphological events whose regulation is essential for closure. Such models also provide an opportunity to investigate potential risk factors and to develop novel preventive therapies. PMID:25032496

  19. Neural Tube Defects

    PubMed Central

    Greene, Nicholas D.E.; Copp, Andrew J.

    2015-01-01

    Neural tube defects (NTDs), including spina bifida and anencephaly, are severe birth defects of the central nervous system that originate during embryonic development when the neural tube fails to close completely. Human NTDs are multifactorial, with contributions from both genetic and environmental factors. The genetic basis is not yet well understood, but several nongenetic risk factors have been identified as have possibilities for prevention by maternal folic acid supplementation. Mechanisms underlying neural tube closure and NTDs may be informed by experimental models, which have revealed numerous genes whose abnormal function causes NTDs and have provided details of critical cellular and morphological events whose regulation is essential for closure. Such models also provide an opportunity to investigate potential risk factors and to develop novel preventive therapies. PMID:25032496

  20. Optical, UV, and EUV Oscillations of SS Cygni in Outburst

    SciTech Connect

    Mauche, C W

    2003-12-19

    I provide a review of observations in the optical, UV (HST), and EUV (EUVE and Chandra LETG) of the rapid periodic oscillations of nonmagnetic, disk-accreting, high mass-accretion rate cataclysmic variables (CVs), with particular emphasis on the dwarf nova SS Cyg in outburst. In addition, I drawn attention to a correlation, valid over nearly six orders of magnitude in frequency, between the frequencies of the quasi-periodic oscillations (QPOs) of white dwarf, neutron star, and black hole binaries. This correlation identifies the high frequency quasi-coherent oscillations (so-called ''dwarf nova oscillations'') of CVs with the kilohertz QPOs of low mass X-ray binaries (LMXBs), and the low frequency and low coherence QPOs of CVs with the horizontal branch oscillations (or the broad noise component identified as such) of LMXBs. Assuming that the same mechanisms produce the QPOs of white dwarf, neutron star, and black hole binaries, this correlation has important implications for QPO models.

  1. The weldability of consolidated rapidly solidified Type 304 SS powders

    SciTech Connect

    Clark, D.E.; Korth, G.E.

    1988-01-01

    The joining requirements of rapidly solidified materials were evaluated. Type 304 stainless steel produced by centrifugal atomization and consolidated by hot extrusion was the primary material tested; vacuum gas atomized Type 304 SS materials and other consolidation methods, inluding HIP and dynamic (explosive) consolidation, were also examined. Several welding processes were evaluated, including gas tungsten arc, electron beam, friction, capacitor discharge, and explosive welding. Heat-affected zone grain growth was suppressed. Residual helium in the centrifugally atomized material was found to form moderate to severe porosity in all fusion welding processes; porosity appeared to be suppressed in friction and explosive welding. High energy density fusion welding processes (electron beam and capacitor discharge) were thermally modeled, and solidification was found to occur at cooling rates far exceeding those of the original powder material and to produce correspondingly fine microstrucures. 10 refs., 9 figs., 2 tabs.

  2. On the long-term behavior of SS Cygni

    NASA Technical Reports Server (NTRS)

    Cannizzo, John K.; Mattei, Janet A.

    1992-01-01

    The complete historical light curve of the dwarf nova SS Cygni taken by the American Association of Variable Star Observers from September 27, 1896 to April 7, 1992 is examined. The data consist of 29,387 daily means based on 180,233 individual observations. The statistical properties of the outburst durations, quiescence intervals, and cycle times associated with the 705 outbursts which occurred during this time are investigated. No significant difference is found between the correlations of the duration of a burst with the length of the following cycle time and the duration of a burst with the length of the preceding cycle time. On the basis of long-term moving averages, the inverse relation between cycle time and quiescent magnitude pointed out by Warner (1987, 1988) is confirmed.

  3. More on the circumbinary disk of SS 433

    NASA Astrophysics Data System (ADS)

    Bowler, M. G.

    2011-07-01

    Context. Certain lines in spectra of the Galactic microquasar SS 433, in particular the brilliant Balmer Hα line, have been interpreted as emission from a circumbinary disk. In this interpretation the orbital speed of the glowing material is in excess of 200 km s-1 and the mass of the binary system in excess of 40 M⊙. A very simple model for excitation of disk material is in remarkable agreement with the observations, yet it seems that the very existence of a circumbinary disk is regarded as controversial. Aims: We investigate whether analysis of optical data from Hα and He I spectral lines in terms of a model, in which the disk is excited by radiation from the close environment of the compact object, can further illuminate the origin of these split spectral lines. Methods: A model in which the excitation of any given patch of putative circumbinary disk material is proportional to the inverse square of its instantaneous distance from the compact object was constructed and compared with published spectra, taken almost nightly over two orbital periods of the binary system. The Hα and He I lines were analysed as superpositions of Gaussian components. Results: The new model provides an excellent description of the observations. The variations of the Hα and He I spectra with orbital phase are described quantitatively, provided the radius of the orbit of the emitting ring is not much greater than the radius of the closest stable circumbinary orbit. The observed variations with orbital phase are not consistent with an origin in a radially expanding ring. Conclusions: The new analysis has greatly strengthened the case for a circumbinary disk orbiting the SS 433 system with a speed of over 200 km s-1 and presents supposed alternative explanations with major difficulties. If the circumbinary disk scenario is essentially correct, the mass of the binary system must exceed 40 M⊙ and the compact object must be a rather massive stellar black hole. This possibility should

  4. PRODUCTION OF URANIUM TUBING

    DOEpatents

    Creutz, E.C.

    1958-04-15

    The manufacture of thin-walled uranium tubing by the hot-piercing techique is described. Uranium billets are preheated to a temperature above 780 d C. The heated billet is fed to a station where it is engaged on its external surface by three convex-surfaced rotating rollers which are set at an angle to the axis of the billet to produce a surface friction force in one direction to force the billet over a piercing mandrel. While being formed around the mandrel and before losing the desired shape, the tube thus formed is cooled by a water spray.

  5. Controllable g5p-Protein-Directed Aggregation of ssDNA-Gold Nanoparticles

    SciTech Connect

    Lee, S.; Maye, M; Zhang, Y; Gang, O; van der Lelie, D

    2009-01-01

    We assembled single-stranded DNA (ssDNA) conjugated nanoparticles using the phage M13 gene 5 protein (g5p) as the molecular glue to bind two antiparallel noncomplementary ssDNA strands. The entire process was controlled tightly by the concentration of the g5p protein and the presence of double-stranded DNA. The g5p-ssDNA aggregate was disintegrated by hybridization with complementary ssDNA (C-ssDNA) that triggers the dissociation of the complex. Polyhistidine-tagged g5p was bound to nickel nitrilotriacetic acid (Ni2+-NTA) conjugated nanoparticles and subsequently used to coassemble the ssDNA-conjugated nanoparticles into multiparticle-type aggregates. Our approach offers great promise for designing biologically functional, controllable protein/nanoparticle composites.

  6. Electrochemical Impedance Spectroscopy of Alloys in a Simulated Space Shuttle Launch Environment

    NASA Technical Reports Server (NTRS)

    Calle, L. M.; Kolody, M. R.; Vinje, R. D.

    2004-01-01

    Type 304L stainless steel (304L SS) tubing is currently used in various supply lines that service the Orbiter at NASA's John F. Kennedy Space Center Launch Pads in Florida (USA). The atmosphere at the Space Shuffle launch site is very corrosive due to a combination of factors, such as the proximity of the Atlantic Ocean and the concentrated hydrochloric acid produced by the fuel combustion reaction in the solid rocket boosters. The acidic chloride environment is aggressive to most metals and causes severe pitting in many of the common stainless steel alloys such as 304L SS. Stainless steel tubing is susceptible to pitting corrosion that can cause cracking and rupture of both high-pressure gas and fluid systems. Outages in the systems where failures occur can impact the normal operation of the shuttle and launch schedules. The use of a more corrosion resistant tubing alloy for launch pad applications would greatly reduce the probability of failure, improve safety, lessen maintenance costs, and reduce downtime. A study which included ten alloys was undertaken to find a more corrosion resistant material to replace the existing 304L SS tubing. The study included atmospheric exposure at NASA's John F. Kennedy Space Center outdoor corrosion test site near the launch pads and electrochemical measurements in the laboratory which included DC techniques and electrochemical impedance spectroscopy (EIS). This paper presents the results from EIS measurements on three of the alloys: AL6XN (UN N08367), 254SMO (UNS S32l54), and 304L SS (UNS S30403). Type 304L SS was included in the study as a control. The alloys were tested in three electrolyte solutions which consisted of neutral 3.55% NaC1, 3.55% NaCl in O.1N HC1, and 3.55% NaCl in 1.ON HC1. The solutions were chosen to simulate environments that were expected to be less, similar, and more aggressive, respectively, than those present at the Space Shuttle launch pads. The results from the EIS measurements were analyzed to

  7. Effectiveness of bomber deployed autonomous airborne vehicles in finding rail mobile SS-24s

    SciTech Connect

    Abey, A.E.; Erickson, S.A.; Norquist, P.D.

    1990-08-01

    Computer simulation predictions of the effectiveness of autonomous airborne vehicles in finding rail mobile SS-24s are presented. Effectiveness is discussed for several autonomous airborne vehicle endurances and survivabilities for the search area southwest of Moscow. The effect of where the Soviets place the SS-24s on the rail network was also investigated. The simulation predicts significant variations in the ability of a multi-autonomous airborne vehicle system to find SS-24s with these parameters. 12 figs., 1 tab.

  8. Manufacturing SP-100 rhenium tubes

    NASA Astrophysics Data System (ADS)

    Sayre, Edwin D.; Ruffo, Thomas J.

    1992-01-01

    A process for producing high quality, thin walled, wrought, rhenium tubing was successfully developed and qualified in the SP-100 fuel fabrication program. Rhenium was selected for the fuel-cladding barrier versus tungsten because of the cold workability and nuclear characteristics of rhenium. Several tube fabricating processes including swaging, drawing, and extruding sintered tube shells and chemical vapor deposition were evaluated before a drawn tube made by forming and electron beam welding rhenium strip was selected as the most cost effective. The process for making the rhenium tubes is discussed in general and the tube, room temperature, tensile properties are compared favorably with the properties reported in the literature.

  9. Synthesis and characterization of PEG-P(MAA-SS-VCL) nanoparticles

    NASA Astrophysics Data System (ADS)

    Yu, L. L.; Yang, K.; Mu, R. H.; Zhang, N.; Su, L.

    2016-07-01

    The PEG-P(MAA-SS-VCL) nanoparticles were obtained using disulfide containing dimethacrylate (SS) as cross-linking agent, using polyethylene glycol methyl acrylate (PEGMA), N-Vinyl-ε-caprolactam (VCL), and methacrylic acid (MAA) as monomers via homogeneous polymerization in aqueous. The PEG-P(MAA-SS-VCL) nanoparticles were characterized by FT-IR and TGA. The particle size and morphology variation in different environments were detected by dynamic light scattering (DLS) and scanning electron microscopy (SEM). It is the very method that PEG-P(MAA-SS-VCL) nanoparticles can be obtained in this study.

  10. APOBEC3G Interacts with ssDNA by Two Modes: AFM Studies

    NASA Astrophysics Data System (ADS)

    Shlyakhtenko, Luda S.; Dutta, Samrat; Banga, Jaspreet; Li, Ming; Harris, Reuben S.; Lyubchenko, Yuri L.

    2015-10-01

    APOBEC3G (A3G) protein has antiviral activity against HIV and other pathogenic retroviruses. A3G has two domains: a catalytic C-terminal domain (CTD) that deaminates cytidine, and a N-terminal domain (NTD) that binds to ssDNA. Although abundant information exists about the biological activities of A3G protein, the interplay between sequence specific deaminase activity and A3G binding to ssDNA remains controversial. We used the topographic imaging and force spectroscopy modalities of Atomic Force Spectroscopy (AFM) to characterize the interaction of A3G protein with deaminase specific and nonspecific ssDNA substrates. AFM imaging demonstrated that A3G has elevated affinity for deaminase specific ssDNA than for nonspecific ssDNA. AFM force spectroscopy revealed two distinct binding modes by which A3G interacts with ssDNA. One mode requires sequence specificity, as demonstrated by stronger and more stable complexes with deaminase specific ssDNA than with nonspecific ssDNA. Overall these observations enforce prior studies suggesting that both domains of A3G contribute to the sequence specific binding of ssDNA.

  11. Heat-shrink plastic tubing seals joints in glass tubing

    NASA Technical Reports Server (NTRS)

    Del Duca, B.; Downey, A.

    1968-01-01

    Small units of standard glass apparatus held together by short lengths of transparent heat-shrinkable polyolefin tubing. The tubing is shrunk over glass O-ring type connectors having O-rings but no lubricant.

  12. Orbital tube flaring system produces tubing connectors with zero leakage

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1967-01-01

    An orbital tube flaring system produces tubing connectors with a zero-leak potential needed in high pressure hydraulic and pneumatic systems. The flaring system incorporates a rolling cone and rolling die to closely control flare characteristics.

  13. Neural Tube Defects

    MedlinePlus

    ... The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, the fetal spinal column doesn't close completely. There is usually nerve damage that causes at least some paralysis of the legs. In anencephaly, ... National Institute of Child Health and Human Development

  14. Investigation of Pitot tubes

    NASA Technical Reports Server (NTRS)

    Herschel, W H; Buckingham, E

    1917-01-01

    Report describes the principles of operation and characteristics of some of the instruments which have been devised or used to measure both low and high speeds of aeroplanes. Since the pitot tube is the instrument which has been most commonly used in the United States and Great Britain as a speedometer for aeroplanes, it is treated first and somewhat more fully than the others.

  15. PEG tube insertion - discharge

    MedlinePlus

    ... to 3 times a day. Use either mild soap and water or sterile saline (ask you provider). You may ... skin and tube. Be gentle. If you used soap, gently clean again with plain water. Dry the skin well with a clean towel ...

  16. Tube Feeding Transition Plateaus

    ERIC Educational Resources Information Center

    Klein, Marsha Dunn

    2007-01-01

    The journey children make from tube feeding to oral feeding is personal for each child and family. There is a sequence of predictable plateaus that children climb as they move toward orally eating. By better understanding this sequence, parents and children can maximize the development, learning, enjoyment and confidence at each plateau. The…

  17. Downhole pulse tube refrigerators

    SciTech Connect

    Swift, G.; Gardner, D.

    1997-12-01

    This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

  18. Multimodal Pyrethroid Resistance in Malaria Vectors, Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. in Western Kenya

    PubMed Central

    Kawada, Hitoshi; Dida, Gabriel O.; Ohashi, Kazunori; Komagata, Osamu; Kasai, Shinji; Tomita, Takashi; Sonye, George; Maekawa, Yoshihide; Mwatele, Cassian; Njenga, Sammy M.; Mwandawiro, Charles; Minakawa, Noboru; Takagi, Masahiro

    2011-01-01

    Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. are the most important species for malaria transmission. Pyrethroid resistance of these vector mosquitoes is one of the main obstacles against effective vector control. The objective of the present study was to monitor the pyrethroid susceptibility in the 3 major malaria vectors in a highly malaria endemic area in western Kenya and to elucidate the mechanisms of pyrethroid resistance in these species. Gembe East and West, Mbita Division, and 4 main western islands in the Suba district of the Nyanza province in western Kenya were used as the study area. Larval and adult collection and bioassay were conducted, as well as the detection of point mutation in the voltage-gated sodium channel (1014L) by using direct DNA sequencing. A high level of pyrethroid resistance caused by the high frequency of point mutations (L1014S) was detected in An. gambiae s.s. In contrast, P450-related pyrethroid resistance seemed to be widespread in both An. arabiensis and An. funestus s.s. Not a single L1014S mutation was detected in these 2 species. A lack of cross-resistance between DDT and permethrin was also found in An. arabiensis and An. funestus s.s., while An. gambiae s.s. was resistant to both insecticides. It is noteworthy that the above species in the same area are found to be resistant to pyrethroids by their unique resistance mechanisms. Furthermore, it is interesting that 2 different resistance mechanisms have developed in the 2 sibling species in the same area individually. The cross resistance between permethrin and DDT in An. gambiae s.s. may be attributed to the high frequency of kdr mutation, which might be selected by the frequent exposure to ITNs. Similarly, the metabolic pyrethroid resistance in An. arabiensis and An. funestus s.s. is thought to develop without strong selection by DDT. PMID:21853038

  19. Multimodal pyrethroid resistance in malaria vectors, Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. in western Kenya.

    PubMed

    Kawada, Hitoshi; Dida, Gabriel O; Ohashi, Kazunori; Komagata, Osamu; Kasai, Shinji; Tomita, Takashi; Sonye, George; Maekawa, Yoshihide; Mwatele, Cassian; Njenga, Sammy M; Mwandawiro, Charles; Minakawa, Noboru; Takagi, Masahiro

    2011-01-01

    Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. are the most important species for malaria transmission. Pyrethroid resistance of these vector mosquitoes is one of the main obstacles against effective vector control. The objective of the present study was to monitor the pyrethroid susceptibility in the 3 major malaria vectors in a highly malaria endemic area in western Kenya and to elucidate the mechanisms of pyrethroid resistance in these species. Gembe East and West, Mbita Division, and 4 main western islands in the Suba district of the Nyanza province in western Kenya were used as the study area. Larval and adult collection and bioassay were conducted, as well as the detection of point mutation in the voltage-gated sodium channel (1014L) by using direct DNA sequencing. A high level of pyrethroid resistance caused by the high frequency of point mutations (L1014S) was detected in An. gambiae s.s. In contrast, P450-related pyrethroid resistance seemed to be widespread in both An. arabiensis and An. funestus s.s. Not a single L1014S mutation was detected in these 2 species. A lack of cross-resistance between DDT and permethrin was also found in An. arabiensis and An. funestus s.s., while An. gambiae s.s. was resistant to both insecticides. It is noteworthy that the above species in the same area are found to be resistant to pyrethroids by their unique resistance mechanisms. Furthermore, it is interesting that 2 different resistance mechanisms have developed in the 2 sibling species in the same area individually. The cross resistance between permethrin and DDT in An. gambiae s.s. may be attributed to the high frequency of kdr mutation, which might be selected by the frequent exposure to ITNs. Similarly, the metabolic pyrethroid resistance in An. arabiensis and An. funestus s.s. is thought to develop without strong selection by DDT. PMID:21853038

  20. Tubing For Sampling Hydrazine Vapor

    NASA Technical Reports Server (NTRS)

    Travis, Josh; Taffe, Patricia S.; Rose-Pehrsson, Susan L.; Wyatt, Jeffrey R.

    1993-01-01

    Report evaluates flexible tubing used for transporting such hypergolic vapors as those of hydrazines for quantitative analysis. Describes experiments in which variety of tubing materials, chosen for their known compatibility with hydrazine, flexibility, and resistance to heat.

  1. Multiple test tubes stirred mechanically

    NASA Technical Reports Server (NTRS)

    Leon, H. J.; Strong, I. J.

    1965-01-01

    Mechanical device simultaneously stirs multiple test tubes under controlled laboratory conditions. The invention provides a variable stirring rate, minimal amount of contamination of tube contents, unattended and simple operation, and easy maintenance and cleaning.

  2. Quarter-wave pulse tube

    NASA Astrophysics Data System (ADS)

    Swift, G. W.; Gardner, D. L.; Backhaus, S. N.

    2011-10-01

    In high-power pulse-tube refrigerators, the pulse tube itself can be very long without too much dissipation of acoustic power on its walls. The pressure amplitude, the volume-flow-rate amplitude, and the time phase between them evolve significantly along a pulse tube that is about a quarter-wavelength long. Proper choice of length and area makes the oscillations at the ambient end of the long pulse tube optimal for driving a second, smaller pulse-tube refrigerator, thereby utilizing the acoustic power that would typically have been dissipated in the first pulse-tube refrigerator's orifice. Experiments show that little heat is carried from the ambient heat exchanger to the cold heat exchanger in such a long pulse tube, even though the oscillations are turbulent and even when the tube is compactly coiled.

  3. Calibration of image dissector tubes

    NASA Technical Reports Server (NTRS)

    Klingman, E. E., III

    1976-01-01

    Technique employs computer-controlled light-emitting diode (LED), precision machined mask, and analog-to-digital coverter (ADC). Computer turns on LED which floods masked face of tube. Intensity pattern, generated as tube is electromagnetically swept, is fed to ADC which controls tube calibration.

  4. Enteral Tube Feeding and Pneumonia

    ERIC Educational Resources Information Center

    Gray, David Sheridan; Kimmel, David

    2006-01-01

    To determine the effects of enteral tube feeding on the incidence of pneumonia, we performed a retrospective review of all clients at our institution who had gastrostomy or jejunostomy tubes placed over a 10-year period. Ninety-three subjects had a history of pneumonia before feeding tube insertion. Eighty had gastrostomy and 13, jejunostomy…

  5. Sleeve puller salvages welded tubes

    NASA Technical Reports Server (NTRS)

    Weaver, J. F.

    1980-01-01

    Tool removes sleeve remnants without distorting or damaging tubes, unlike pliers and other conventional handtools. Tubes can be reused, saving time, labor, and material in many applications. Sleeve-removal fixture consists of pressure screw, swing arm, locking screws, and base. It removes sleeve remnant from tubing after welded joint has been sawed through.

  6. Method for reinforcing tubing joints

    NASA Technical Reports Server (NTRS)

    Kinzler, J.; Lee, W. S.

    1968-01-01

    Joint repair technique uses a longitudinally split aluminum shield over the joint ferrule and immediately adjacent tubing to reseal or reinforce leaking or weak joints in small tubing. Epoxy resin coating on inside surfaces of the two shield halves provides a tightly sealed bond between shield and tubing.

  7. Tubing cutter for tight spaces

    NASA Technical Reports Server (NTRS)

    Girala, A. S.

    1980-01-01

    Cutter requires few short swings of handle to rotate its cutting edge full 360 around tube. It will cut tubing installed in confined space that prevents free movement of conventional cutter. Cutter is snapped onto tube and held in place by spring-loaded clamp. Screw ratchet advances cutting wheel.

  8. Isolation of a new ssDNA aptamer against staphylococcal enterotoxin B based on CNBr-activated sepharose-4B affinity chromatography.

    PubMed

    Hedayati Ch, Mojtaba; Amani, Jafar; Sedighian, Hamid; Amin, Mohsen; Salimian, Jafar; Halabian, Raheleh; Imani Fooladi, Abbas Ali

    2016-09-01

    Staphylococcus aureus are potent human pathogens possessing arsenal of virulence factors. Staphylococcal food poisoning (SFP) and respiratory infections mediated by staphylococcal enterotoxin B (SEB) are common clinical manifestations. Many diagnostic techniques are based on serological detection and quantification of SEB in different food and clinical samples. Aptamers are known as new therapeutic and detection tools which are available in different ssDNA, dsDNA and protein structures. In this study, we used a new set of ssDNA aptamers against SEB. The methods used included preparation of a dsDNA library using standard SEB protein as the target analyte, affinity chromatography matrix in microfuge tubes, SELEX procedures to isolate specific ssDNA-aptamer as an affinity ligand, aptamer purification using ethanol precipitation method, affinity binding assay using ELISA, aptamer cloning and specificity test. Among 12 readable sequences, three of them were selected as the most appropriate aptamer because of their affinity and specificity to SEB. This study presents a new set of ssDNA aptamer with favorable selectivity to SEB through 12 rounds of SELEX. Selected aptamers were used to detect SEB in infected serum samples. Results showed that SEB c1 aptamer (2 µg SEB/100 nM aptamer) had favorable specificity to SEB (kd  = 2.3 × 10(-11) ). In conclusion, aptamers can be considered as useful tools for detecting and evaluating SEB. The results showed that affinity chromatography was an affordable assay with acceptable accuracy to isolate sensitive and selective novel aptamers. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27091327

  9. Tubing rotator reduces tubing wear in rod pumped wells

    SciTech Connect

    Graham, M. ); Brown, C. )

    1994-04-04

    Tubing failures are both expensive and time-consuming. The most common failure results from rod cutting, or, erosion of the tubing ID because of continuous, reciprocating contact with the rod string. Installation of tubing rotators has decreased tubing failures in West Texas waterflood sucker-rod pumped wells. Pumping unit movement powers the rotator system, turning the tubing string at about 1 revolution/day. The rotator system has both surface and subsurface components. A reduction gear box attached to the walking beam converts the pumping unit's reciprocating strokes into rotary motion. A drive line transfers this rotary motion to a gear-driven suspension mandrel in the rotating tubing hanger. Near the bottom of the tubing string, a rotating tubing anchor/catcher allows the entire tubing string, including the tail pipe, seating nipple, and gas and mud anchor to rotate. The rotator hanger suspends the weight of the tubing string on a bearing system. One model of the hanger has a load capacity of 135,000 lb. A surface swivel allows rotation below the pumping tee so that the flow lines remain stationary. Also included in the string is a safety shear coupling to prevent over torquing the tubing.

  10. Tritium release from SS316 under vacuum condition

    SciTech Connect

    Torikai, Y.; Penzhorn, R.D.

    2015-03-15

    The plasma facing surface of the ITER vacuum vessel, partly made of low carbon austenitic stainless steel type 316L, will incorporate tritium during machine operation. In this paper the kinetics of tritium release from stainless steel type 316 into vacuum and into a noble gas stream are compared and modelled. Type 316 stainless steel specimens loaded with tritium either by exposure to 1.2 kPa HT at 573 K or submersion into liquid HTO at 298 K showed characteristic thin surface layers trapping tritium in concentrations far higher than those determined in the bulk. The evolution of the tritium depth profile in the bulk during heating under vacuum was non-discernible from that of tritium liberated into a stream of argon. Only the relative amount of the two released tritium-species, i.e. HT or HTO, was different. Temperature-dependent depth profiles could be predicted with a one-dimensional diffusion model. Diffusion coefficients derived from fitting of the tritium release into an evacuated vessel or a stream of argon were found to be (1.4 ± 1.0)*10{sup -7} and (1.3 ± 0.9)*10{sup -9} cm{sup 2}/s at 573 and 423 K, respectively. Polished surfaces on type SS316 stainless steel inhibit considerably the thermal release rate of tritium.

  11. ASCA observations of SS Cygni during an anomalous outburst

    NASA Technical Reports Server (NTRS)

    Nousek, John A.; Baluta, Christopher J.; Corbet, Robin H. D.; Mukai, Koji; Osborne, Julian P.; Ishida, Manabu

    1994-01-01

    SS Cygni was observed by the ASCA satellite on 1993 May 27, the first cataclysmic variable studied by ASCA. The observations were conducted while the system was in an outburst of the 'anomalous' variety. The SIS spectrum cannot be explained by two-temperature Raymond-Smith coronal plasma models as invoked in previous studies with lower spectral resolution. Significantly better agreement is found for models with plasma emission at kT = 0.8, 3.5 keV and thermal bremsstrahlung at kT = 18 keV. The gas imaging spectrometer (GIS) data are consistent with the solid state imaging spectrometer (SIS) data, showing evidence for Fe line emission but showing no evidence of pulsation over times ranging from seconds to minutes. These observations seem at variance with standard theory in two regards: we simultaneously see hard X-rays and optically thin soft X-rays while the system is in outburst, and we see a nonsmooth emission measure distribution. We speculate on possible scenarios which might resolve these differences.

  12. On the bizarre gamma-ray spectrum of SS 433

    NASA Technical Reports Server (NTRS)

    Helfer, H. L.; Savedoff, M. P.

    1984-01-01

    Lamb et al. (1983) have announced the discovery of a pair of gamma-ray lines interpretable as emission of the 1.368 MeV line of Mg-24 in the two oppositely directed relativistic jets of SS 433. The mass loss rate related to the Mg-24 and the kinetic energy flux of the Mg-24 are considered. In the present investigation, it is shown that the mass loss flux must be well in excess of 0.00001 solar mass per yr, while the abundance of the gamma-emitting nucleus is extremely high. Attention is given to the calculation of the gamma-ray production efficiency factor, the size of the emitting region, reaction processes, and X-ray luminosity. It is concluded that for plasma beam models, there must be a substantial overabundance, by a factor of 100 to approximately 1000, of the gamma-line producing nucleus. The association of the gamma-ray lines with Mg-24 is reasonable but not secure.

  13. On the dust jet model of SS 433

    NASA Technical Reports Server (NTRS)

    Helfer, H. L.; Savedoff, M. P.

    1986-01-01

    The dust jet model for production of narrow gamma-ray lines from SS 433 is examined and shown to be implausible. Sputtering rates at disk temperatures are high, and self-absorption rates in the disk and jet are important; both imply that dust particles would easily be destroyed. The energy deposited in the dust jet particles by collisions with the ambient protons should be radiated in the optical and infrared in amounts greatly exceeding that observed. The dust momentum pumps ambient gas out of the beam at rates which imply that for the steady state, the ambient gas has to have an initial temperature exceeding one million K. The ambient medium is also required to have densities exceeding those postulated for the H-alpha-emitting gas jet, and the interaction within the gas jet material would result in appreciable broadening of the H-alpha emission lines. At present, there is no viable model for the steady state production of the gamma-ray line radiation.

  14. Interfacial Shear Strength of Oxide Scale and SS 441 Substrate

    SciTech Connect

    Liu, Wenning N.; Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2011-05-01

    Recent developments on decreasing the operating temperature for Solid Oxide Fuel Cells (SOFCs) have enabled the use of high temperature ferritic alloys as interconnect materials. Oxide scale will inevitably grow on the ferritic interconnects in a high temperature oxidation environment of SOFCs. The growth of the oxide scale induces growth stresses in the scale layer and on the scale/substrate interface. These growth stresses combined with the thermal stresses induced upon stacking cooling by the thermal expansion coefficient mismatch between the oxide scale and the substrate may lead to scale delamination/buckling and eventual spallation, which may lead to serious cell performance degradation. Hence the interfacial adhesion strength between the oxide scale and the substrate is crucial to the reliability and durability of the metallic interconnect in SOFC operating environments. In this paper, we applied an integrated experimental/modeling methodology to quantify the interfacial adhesion strength between the oxide scale and the SS 441 metallic interconnect. The predicted interfacial strength is discussed in details.

  15. Induction plasma tube

    DOEpatents

    Hull, D.E.

    1982-07-02

    An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

  16. Induction plasma tube

    DOEpatents

    Hull, Donald E.

    1984-01-01

    An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

  17. YouTube Physics

    NASA Astrophysics Data System (ADS)

    Riendeau, Diane

    2012-09-01

    To date, this column has presented videos to show in class, Don Mathieson from Tulsa Community College suggested that YouTube could be used in another fashion. In Don's experience, his students are not always prepared for the mathematic rigor of his course. Even at the high school level, math can be a barrier for physics students. Walid Shihabi, a colleague of Don's, decided to compile a list of YouTube videos that his students could watch to relearn basic mathematics. I thought this sounded like a fantastic idea and a great service to the students. Walid graciously agreed to share his list and I have reproduced a large portion of it below.

  18. Induction plasma tube

    SciTech Connect

    Hull, D.E.

    1984-02-14

    An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

  19. 27 CFR 40.171 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... applications may be filed with the district director of any such district as provided for in 26 CFR 301.6091-1... Form SS-4. 40.171 Section 40.171 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Payment of Taxes on Tobacco Products § 40.171 Execution and filing of Form SS-4. The application on...

  20. 27 CFR 40.171 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... applications may be filed with the district director of any such district as provided for in 26 CFR 301.6091-1... Form SS-4. 40.171 Section 40.171 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Payment of Taxes on Tobacco Products § 40.171 Execution and filing of Form SS-4. The application on...

  1. 27 CFR 40.171 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... applications may be filed with the district director of any such district as provided for in 26 CFR 301.6091-1... Form SS-4. 40.171 Section 40.171 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Payment of Taxes on Tobacco Products § 40.171 Execution and filing of Form SS-4. The application on...

  2. 27 CFR 40.171 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... applications may be filed with the district director of any such district as provided for in 26 CFR 301.6091-1... Form SS-4. 40.171 Section 40.171 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Payment of Taxes on Tobacco Products § 40.171 Execution and filing of Form SS-4. The application on...

  3. Psychometric Reevaluation of the Women in Science Scale (WiSS)

    ERIC Educational Resources Information Center

    Owen, Steven V.; Toepperwein, Mary Anne; Pruski, Linda A.; Blalock, Cheryl L.; Liu, Yan; Marshall, Carolyn E.; Lichtenstein, Michael J.

    2007-01-01

    The Women in Science Scale (WiSS) was first developed in 1984, and is still being used in contemporary studies, yet its psychometric properties have not been evaluated with current statistical methods. In this study, the WiSS was administered in its original 27-item form to 1,439 middle and high school students. Confirmatory factor analysis based…

  4. 27 CFR 40.171 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... applications may be filed with the district director of any such district as provided for in 26 CFR 301.6091-1... Form SS-4. 40.171 Section 40.171 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Payment of Taxes on Tobacco Products § 40.171 Execution and filing of Form SS-4. The application on...

  5. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Stars and Stripes (S&S) Board of Directors E Appendix E to Part 246 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF.... E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  6. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube...

  7. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube...

  8. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube...

  9. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube...

  10. [Patulous eustachian tube].

    PubMed

    Kovacević, D; Radosavljević, M; Jelesijević, J

    1995-01-01

    Patulous eustachian tube is a pathological condition which exists more often than we make a diagnosis, and a patient is not often aware of his disease. This disease can be manifested with various symptoms: respiratory synchrony noises in the ear, because of the penetration of the air current through the eustachian tube and with the movement of the eardrum outwards and inside, with autophony, reduction of the hearing, the buzzing, dizziness and disturbance of the balance. Two patients are presented. The first one was sick for many years from various chronics exhausted diseases: Jackson's epilepsy, temporary vascular brain disturbances, tuberculosis of lung, stomach ulcer, heart diseases, the patient is from low class, on one side, and also suffers from some local diseases: a paralysis of soft palate and palatal arcs, a chronic catarrhal rhinitis and sinusitis, a deviation of nasal dividing wall and hindered breathing through the nose, on the other side. Many years the patient didn't know for patological condition in the ears and in the eustachian tubes. After improving the hygienic conditions, the physical condition and local therapy, the patient felt much better. The second patient, with considerable shorter evolution of the disease and mild symptomatology, showed the amplified symptoms of the disease of the Eustachian tube in the course of the acute otitis. It is attained a satisfying calming of the manifestative symptoms by remedy therapie. Man must thing about possibility of the appearance of this pathology condition in various disease or conditions, which can take to the fast lost of the weight and physical and moral exhaustion of the patient, i.e. an adult, first as the protection of the appearance of the disease (condition) and afterwards, eventually early and regulary treatment in order to prevent various possible, above mentioned complications. PMID:16296237

  11. Joined concentric tubes

    SciTech Connect

    DeJonghe, Lutgard; Jacobson, Craig; Tucker, Michael; Visco, Steven

    2013-01-01

    Tubular objects having two or more concentric layers that have different properties are joined to one another during their manufacture primarily by compressive and friction forces generated by shrinkage during sintering and possibly mechanical interlocking. It is not necessary for the concentric tubes to display adhesive-, chemical- or sinter-bonding to each other in order to achieve a strong bond. This facilitates joining of dissimilar materials, such as ceramics and metals.

  12. Traveling-Wave Tubes

    NASA Technical Reports Server (NTRS)

    Kory, Carol L.

    1998-01-01

    The traveling-wave tube (TWT) is a vacuum device invented in the early 1940's used for amplification at microwave frequencies. Amplification is attained by surrendering kinetic energy from an electron beam to a radio frequency (RF) electromagnetic wave. The demand for vacuum devices has been decreased largely by the advent of solid-state devices. However, although solid state devices have replaced vacuum devices in many areas, there are still many applications such as radar, electronic countermeasures and satellite communications, that require operating characteristics such as high power (Watts to Megawatts), high frequency (below 1 GHz to over 100 GHz) and large bandwidth that only vacuum devices can provide. Vacuum devices are also deemed irreplaceable in the music industry where musicians treasure their tube-based amplifiers claiming that the solid-state and digital counterparts could never provide the same "warmth" (3). The term traveling-wave tube includes both fast-wave and slow-wave devices. This article will concentrate on slow-wave devices as the vast majority of TWTs in operation fall into this category.

  13. TUBE SHEARING VALVE

    DOEpatents

    Wilner, L.B.

    1960-05-24

    Explosive operated valves can be used to join two or more containers in fluid flow relationship, one such container being a sealed reservoir. The valve is most simply disposed by mounting it on the reservoir so thst a tube extends from the interior of the reservoir through the valve body, terminating at the bottom of the bore in a closed end; other containers may be similarly connected or may be open connected, as desired. The piston of the valve has a cutting edge at its lower end which shears off the closed tube ends and a recess above the cutting edge to provide a flow channel. Intermixing of the fluid being transferred with the explosion gases is prevented by a copper ring at the top of the piston which is force fitted into the bore at the beginning of the stroke. Although designed to avoid backing up of the piston at pressures up to 10,000 psi in the transferred fluid, proper operation is independent of piston position, once the tube ends were sheared.

  14. Tube bundle system

    PubMed Central

    Marchewka, W.; Mohamed, K.; Addis, J.; Karnack, F.

    2015-01-01

    A tube bundle system (TBS) is a mechanical system for continuously drawing gas samples through tubes from multiple monitoring points located in an underground coal mine. The gas samples are drawn via vacuum pump to the surface and are typically analyzed for oxygen, methane, carbon dioxide and carbon monoxide. Results of the gas analyses are displayed and recorded for further analysis. Trends in the composition of the mine atmosphere, such as increasing methane or carbon monoxide concentration, can be detected early, permitting rapid intervention that prevents problems, such as a potentially explosive atmosphere behind seals, fire or spontaneous combustion. TBS is a well-developed technology and has been used in coal mines around the world for more than 50 years. Most longwall coal mines in Australia deploy a TBS, usually with 30 to 40 monitoring points as part of their atmospheric monitoring. The primary uses of a TBS are detecting spontaneous combustion and maintaining sealed areas inert. The TBS might also provide mine atmosphere gas composition data after a catastrophe occurs in an underground mine, if the sampling tubes are not damaged. TBSs are not an alternative to statutory gas and ventilation airflow monitoring by electronic sensors or people; rather, they are an option to consider in an overall mine atmosphere monitoring strategy. This paper describes the hardware, software and operation of a TBS and presents one example of typical data from a longwall coal mine PMID:26306052

  15. Concentric tube support assembly

    DOEpatents

    Rubio, Mark F.; Glessner, John C.

    2012-09-04

    An assembly (45) includes a plurality of separate pie-shaped segments (72) forming a disk (70) around a central region (48) for retaining a plurality of tubes (46) in a concentrically spaced apart configuration. Each segment includes a support member (94) radially extending along an upstream face (96) of the segment and a plurality of annularly curved support arms (98) transversely attached to the support member and radially spaced apart from one another away from the central region for receiving respective upstream end portions of the tubes in arc-shaped spaces (100) between the arms. Each segment also includes a radial passageway (102) formed in the support member for receiving a fluid segment portion (106) and a plurality of annular passageways (104) formed in the support arms for receiving respective arm portions (108) of the fluid segment portion from the radial passageway and for conducting the respective arm portions into corresponding annular spaces (47) formed between the tubes retained by the disk.

  16. Clogging of feeding tubes.

    PubMed

    Marcuard, S P; Perkins, A M

    1988-01-01

    This is a report of an in vitro study evaluating clotting ability of some formulas with intact protein and hydrolyzed protein sources in a series of buffers ranging from a pH of 1 thru 10. The following 10 products were tested: Ensure Plus, Ensure, Enrich, Osmolite, Pulmocare, Citrotein, Resource, Vivonex TEN, Vital, and Hepatic Acid II. Protein (10 and 20 g/liter) was added to Citrotein and Ensure Plus. All formulas were tested at full and some at half strength. Clotting occurred only in premixed intact protein formulas (Pulmocare, Ensure Plus, Osmolite, Enrich, Ensure) and in Resource. No clotting was observed for Citrotein (intact protein formula in powder form), Vital, Vivonex TEN, and Hepatic Aid II. Adding protein did not cause or increase clotting. In summary, clotting of some liquid formula diet appears to be an important factor causing possible gastric feeding tube occlusion. The following measures may help in preventing this problem: flushing before and after aspirating for gastric residuals to eliminate acid precipitation of formula in the feeding tube, advance the nasogastric feeding tube into the duodenum if possible, and avoid mixing these products with liquid medications having a pH value of 5.0 or less. PMID:3138452

  17. Spectrometer beam tube dimensional optimization

    SciTech Connect

    Dye, S.

    1993-01-04

    This project examined the optimization of the design of a beam tube. An ANSYS model was used to find the minimum tube thickness and the best camber in a beam tube under vacuum and preloaded by a pair of magnet poles. After the tube was modeled one version of it was built for use in the accelerator. This beam tube was put under a vacuum and the dimensional changes were recorded and compared to the ANSYS predictions. These deflection results were quite close to the predicted numbers and would suggest that the stresses are similar to the predictions as well.

  18. Hybrid endotracheal tubes

    NASA Astrophysics Data System (ADS)

    Sakezles, Christopher Thomas

    Intubation involves the placement of a tube into the tracheal lumen and is prescribed in any setting in which the airway must be stabilized or the patient anesthetized. The purpose of the endotracheal tube in these procedures is to maintain a viable airway, facilitate mechanical ventilation, allow the administration of anesthetics, and prevent the reflux of vomitus into the lungs. In order to satisfy these requirements a nearly airtight seal must be maintained between the tube and the tracheal lining. Most conventional endotracheal tubes provide this seal by employing a cuff that is inflated once the tube is in place. However, the design of this cuff and properties of the material are a source of irritation and injury to the tracheal tissues. In fact, the complication rate for endotracheal intubation is reported to be between 10 and 60%, with manifestations ranging from severe sore throat to erosion through the tracheal wall. These complications are caused by a combination of the materials employed and the forces exerted by the cuff on the tracheal tissues. In particular, the abrasive action of the cuff shears cells from the lining, epithelium adhering to the cuff is removed during extubation, and normal forces exerted on the basement tissues disrupt the blood supply and cause pressure necrosis. The complications associated with tracheal intubation may be reduced or eliminated by employing airway devices constructed from hydrogel materials. Hydrogels are a class of crosslinked polymers which swell in the presence of moisture, and may contain more than 95% water by weight. For the current study, several prototype airway devices were constructed from hydrogel materials including poly(vinyl alcohol), poly(hydroxyethyl methacrylate), and poly(vinyl pyrrolidone). The raw hydrogel materials from this group were subjected to tensile, swelling, and biocompatibility testing, while the finished devices were subjected to extensive mechanical simulation and animal trials

  19. Reliability of steam generator tubing

    SciTech Connect

    Kadokami, E.

    1997-02-01

    The author presents results on studies made of the reliability of steam generator (SG) tubing. The basis for this work is that in Japan the issue of defects in SG tubing is addressed by the approach that any detected defect should be repaired, either by plugging the tube or sleeving it. However, this leaves open the issue that there is a detection limit in practice, and what is the effect of nondetectable cracks on the performance of tubing. These studies were commissioned to look at the safety issues involved in degraded SG tubing. The program has looked at a number of different issues. First was an assessment of the penetration and opening behavior of tube flaws due to internal pressure in the tubing. They have studied: penetration behavior of the tube flaws; primary water leakage from through-wall flaws; opening behavior of through-wall flaws. In addition they have looked at the question of the reliability of tubing with flaws during normal plant operation. Also there have been studies done on the consequences of tube rupture accidents on the integrity of neighboring tubes.

  20. Mitochondria-targeted peptide SS-31 attenuates renal injury via an antioxidant effect in diabetic nephropathy.

    PubMed

    Hou, Yanjuan; Li, Shuangcheng; Wu, Ming; Wei, Jinying; Ren, Yunzhuo; Du, Chunyang; Wu, Haijiang; Han, Caili; Duan, Huijun; Shi, Yonghong

    2016-03-15

    Oxidative stress is implicated in the pathogenesis of diabetic kidney injury. SS-31 is a mitochondria-targeted tetrapeptide that can scavenge reactive oxygen species (ROS). Here, we investigated the effect and molecular mechanism of mitochondria-targeted antioxidant peptide SS-31 on injuries in diabetic kidneys and mouse mesangial cells (MMCs) exposed to high-glucose (HG) ambience. CD-1 mice underwent uninephrectomy and streptozotocin treatment prior to receiving daily intraperitoneal injection of SS-31 for 8 wk. The diabetic mice treated with SS-31 had alleviated proteinuria, urinary 8-hydroxy-2-deoxyguanosine level, glomerular hypertrophy, and accumulation of renal fibronectin and collagen IV. SS-31 attenuated renal cell apoptosis and expression of Bax and reversed the expression of Bcl-2 in diabetic mice kidneys. Furthermore, SS-31 inhibited expression of transforming-growth factor (TGF)-β1, Nox4, and thioredoxin-interacting protein (TXNIP), as well as activation of p38 MAPK and CREB and NADPH oxidase activity in diabetic kidneys. In vitro experiments using MMCs revealed that SS-31 inhibited HG-mediated ROS generation, apoptosis, expression of cleaved caspase-3, Bax/Bcl-2 ratio, and cytochrome c (cyt c) release from mitochondria. SS-31 normalized mitochondrial potential (ΔΨm) and ATP alterations, and inhibited the expression of TGF-β1, Nox4, and TXNIP, as well as activation of p38 MAPK and CREB and NADPH oxidase activity in MMCs under HG conditions. SS-31 treatment also could reverse the reduction of thioredoxin (TRX) biologic activity and upregulate expression of thioredoxin 2 (TRX2) in MMCs under HG conditions. In conclusion, this study demonstrates a protective effect of SS-31 against HG-induced renal injury via an antioxidant mechanism in diabetic nephropathy. PMID:26719366

  1. Yet more on the circumbinary disk of SS 433

    NASA Astrophysics Data System (ADS)

    Bowler, M. G.

    2013-08-01

    Context. Certain lines in spectra of the Galactic microquasar SS 433, in particular the Hα line and He I, have been interpreted as emission from a circumbinary disk. In this interpretation the orbital speed of the glowing material is in excess of 200 km s-1 and the mass of the binary system in excess of 40 M⊙. The data show that He I emission fades much faster than Hα. This requirement has been incorporated into successful heuristic models yet has remained unexplained hitherto. Aims: We present a model in which the different characteristics of the Hα and He I lines are naturally explained by the different ionization potentials of the atoms. Methods: A model was constructed in which the emission of any given patch of putative circumbinary disk material is determined both by its illumination and the depth of the ionization zone. Results: The depth of the ionization zones depend on the illumination with photons above ionization thresholds, much higher for He than for H. Thus in the new model the emission distribution round the ring is more uniform for Hα recombination lines than for He I. The new model provides an excellent description of the observations, including Hα intensity. The variations of the Hα and He I spectra with orbital phase are described quantitatively. Conclusions: The new model makes no appeal to ad hoc decay parameters and locates the differences between Hα and He I spectra in the different ionization potentials. If the circumbinary disk scenario is essentially correct, as now seems even more likely, the mass of the binary system must exceed 40 M⊙ and the compact object must be a rather massive stellar black hole.

  2. Interpretation of observations of the circumbinary disk of SS 433

    NASA Astrophysics Data System (ADS)

    Bowler, M. G.

    2010-10-01

    Context. The Galactic microquasar SS 433 possesses a circumbinary disk most clearly seen in the brilliant Balmer Hα emission line. The orbital speed of the glowing material is an important determinant of the mass of the binary system. The circumbinary disk may be fed through the L2 point and in turn may feed a very extended radio feature known as the ruff. Aims: We present (i) an analysis of spectroscopic optical data from Hα and He I spectral lines which reveal the circumbinary disk (ii) comparisons of the rather different signals, to better understand the disk and improve estimates of the rotational speed of the inner rim (iii) a simple model that naturally explains some apparently bizarre spectral variations with orbital phase. Methods: Published spectra, taken almost nightly over two orbital periods of the binary system, show Hα and He I lines. These were analysed as superpositions of Gaussian components and a simple model in terms of a circumbinary disk was constructed. The possible contributions to the signal of an outflow through the L2 point were considered. Results: The data can be understood in terms of a hot spot, generated in proximity to the compact object and rotating round the inner circumbinary disk with a period of 13 days. The glowing material fades with time, quite slowly for the Hα source but more rapidly for the He I spectral lines. The orbital speed of the inner rim is approximately 250 km s-1. It may be that absorption lines attributed to the atmosphere of the companion are in fact formed in this circumbinary material. Conclusions: The mass of the binary system must exceed 40 M_⊙ and the compact object must be a rather massive stellar black hole. The corollary is that the orbital speed of the companion must exceed 130 km s-1.

  3. 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.

  4. Gyrotron transmitting tube

    NASA Technical Reports Server (NTRS)

    Kosmahl, H. G. (Inventor)

    1983-01-01

    An RF transmitting tube for the 20 GHz to 500 GHz range comprises a gyrotron and a multistage depressed collector. A winding provides a magnetic field which acts on spent, spinning or orbiting electrons changing their motion to substantially forward linear motion in a downstream direction. The spent electrons then pass through a focusser into the collector. Nearly all of the electrons injected into the collector will remain within an imaginary envelope as they travel forward toward the end collector plate. The apertures in the collector plates are at least as large in diameter as the envelope at any particular axial position.

  5. Tube thoracostomy; chest tube implantation and follow up

    PubMed Central

    Kuhajda, Ivan; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Huang, Haidong; Li, Qiang; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Papaiwannou, Antonis; Lampaki, Sofia; Papaiwannou, Antonis; Zaric, Bojan; Branislav, Perin; Porpodis, Konstantinos

    2014-01-01

    Pneumothorax is an urgent medical situation that requires urgent treatment. We can divide this entity based on the etiology to primary and secondary. Chest tube implantation can be performed either in the upper chest wall or lower. Both thoracic surgeons and pulmonary physicians can place a chest tube with minimal invasive techniques. In our current work, we will demonstrate chest tube implantation to locations, methodology and tools. PMID:25337405

  6. A novel protein elicitor (SsCut) from Sclerotinia sclerotiorum induces multiple defense responses in plants.

    PubMed

    Zhang, Huajian; Wu, Qun; Cao, Shun; Zhao, Tongyao; Chen, Ling; Zhuang, Peitong; Zhou, Xiuhong; Gao, Zhimou

    2014-11-01

    In this study, we report the cloning of the SsCut gene encoding cutinase from Sclerotinia sclerotiorum. We isolated a 609-bp cDNA encoding a polypeptide of 202 amino acids with a molecular weight of 20.4 kDa. Heterologous expression of SsCut in Escherichia coli (His-SsCut) caused the formation of lesions in tobacco that closely resembled hypersensitive response lesions. Mutational analysis identified the C-terminal-half peptide and the same amino acids indispensable for both enzyme and elicitor activity. His-SsCut was caused cell death in Arabidopsis, soybean (Glycine max), oilseed rape (Brassica napus), rice (Oryza sativa), maize (Zea mays), and wheat (Triticum aestivum), indicating that both dicot and monocot species are responsive to the elicitor. Furthermore, the elicitation of tobacco was effective in the induction of the activities of hydrogen peroxide, phenylalanine ammonia-lyase, peroxides, and polyphenol oxidase. His-SsCut-treated plants exhibited enhanced resistance as indicated by a significant reduction in the number and size of S. sclerotiorum, Phytophthora sojae, and P. nicotianae lesions on leaves relative to controls. Real-time PCR results indicated that the expression of defense-related genes and genes involved in signal transduction were induced by His-SsCut. Our results demonstrate that SsCut is an elicitor that triggers defense responses in plants and will help to clarify its relationship to downstream signaling pathways that induce defense responses. PMID:25149470

  7. Steam generator tube integrity program

    SciTech Connect

    Dierks, D.R.; Shack, W.J.; Muscara, J.

    1996-03-01

    A new research program on steam generator tubing degradation is being sponsored by the U.S. Nuclear Regulatory Commission (NRC) at Argonne National Laboratory. This program is intended to support a performance-based steam generator tube integrity rule. Critical areas addressed by the program include evaluation of the processes used for the in-service inspection of steam generator tubes and recommendations for improving the reliability and accuracy of inspections; validation and improvement of correlations for evaluating integrity and leakage of degraded steam generator tubes, and validation and improvement of correlations and models for predicting degradation in steam generator tubes as aging occurs. The studies will focus on mill-annealed Alloy 600 tubing, however, tests will also be performed on replacement materials such as thermally-treated Alloy 600 or 690. An overview of the technical work planned for the program is given.

  8. Electrochemical Impedance Spectroscopy of Alloys in a Simulated Space Shuttle Launch Environment

    NASA Technical Reports Server (NTRS)

    Calle, L. M.; Kolody, M. R.; Vinje, R. D.; Whitten, M. C.; Li, D.

    2005-01-01

    Corrosion studies began at NASA/Kennedy Space Center in 1966 during the Gemini/Apollo Programs with the evaluation of long-term protective coatings for the atmospheric protection of carbon steel. An outdoor exposure facility on the beach near the launch pad was established for this purpose at that time. The site has provided over 35 years of technical information on the evaluation of the long-term corrosion performance of many materials and coatings as well as on maintenance procedures. Results from these evaluations have helped NASA find new materials and processes that increase the safety and reliability of our flight hardware, launch structures, and ground support equipment. The launch environment at the Kennedy Space Center (KSC) is extremely corrosive due to the combination of ocean salt spray, heat, humidity, and sunlight. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pad were rendered even more severe by the acidic exhaust from the solid rocket boosters. Over the years, many materials have been evaluated for their corrosion performance under conditions similar to those found at the launch pads. These studies have typically included atmospheric exposure and evaluation with conventional electrochemical methods such as open circuit potential (OCP) measurements, polarization techniques, and electrochemical impedance spectroscopy (EIS). The atmosphere at the Space Shuttle launch site is aggressive to most metals and causes severe pitting in many of the common stainless steel alloys such as type 304L stainless steel (304L SS). A study was undertaken to find a more corrosion resistant material to replace the existing 304L SS tubing. This paper presents the results from atmospheric exposure as well as electrochemical measurements on the corrosion resistance of AL-6XN (UNS N08367) and 254-SMO (UNS S32154). Type 304L SS (UNS S30403) was used as a control. Conditions at the Space Shuttle launch pad were

  9. Tubing for augmented heat transfer

    SciTech Connect

    Yampolsky, J.S.; Pavlics, P.

    1983-08-01

    The objectives of the program reported were: to determine the heat transfer and friction characteristics on the outside of spiral fluted tubing in single phase flow of water, and to assess the relative cost of a heat exchanger constructed with spiral fluted tubing with one using conventional smooth tubing. An application is examined where an isolation water/water heat exchanger was used to transfer the heat from a gaseous diffusion plant to an external system for energy recovery. (LEW)

  10. Ion plated electronic tube device

    DOEpatents

    Meek, T.T.

    1983-10-18

    An electronic tube and associated circuitry which is produced by ion plating techniques. The process is carried out in an automated process whereby both active and passive devices are produced at very low cost. The circuitry is extremely reliable and is capable of functioning in both high radiation and high temperature environments. The size of the electronic tubes produced are more than an order of magnitude smaller than conventional electronic tubes.

  11. YouTube Sharathon Crackerbarrel

    NASA Astrophysics Data System (ADS)

    Riendeau, Diane

    2012-10-01

    This year at the AAPT Summer Meeting in Philadelphia, there was a session called ``YouTube Sharathon Crackerbarrel.'' The session allowed many teachers to share their YouTube videos and explain how they use YouTube in their classroom. Unfortunately, I had a conflicting meeting and had to miss this session. Dean Baird was the originator of the session and also served as host. In addition, he forwarded a few of the best videos to me.

  12. Improved Mechanical Seals For Tubes

    NASA Technical Reports Server (NTRS)

    Babel, Henry W.; Anderson, Raymond H.; Fuson, Phillip L.; Chickles, Colin D.; Jones, Cherie A.

    1996-01-01

    Improved tube-to-fitting seals made by application of soft metal pieces to either ends of tubes or to interior of fittings. Metal silver, gold, platinum, tin, or other easily malleable metal selected to be inert with fluid of use. Metal plated, evaporated, or sputter-deposited. Coat of soft metal thin, so no changes required in design or tolerances of standard fittings. Technique suitable for hydraulic or other fluid systems in which leakage from mechanically joined sections of tubes occur.

  13. Large short- and long-term Hikurangi margin, New Zealand SSEs in 2013, and possible triggering of moderate to large seismicity during the SSEs

    NASA Astrophysics Data System (ADS)

    Wallace, L. M.; Fry, B.; Bannister, S. C.; Hamling, I. J.; Ito, Y.; Obara, K.

    2013-12-01

    The Hikurangi margin has been the site of 3 large slow slip events (SSEs) during the 2013 period. These include a recurrence of the deep (30-50 km depth) long-term Kapiti SSE that began in January 2013, as well as a large, shallow (Mw 6.8, <15 km depth) SSE on the central Hikurangi subduction thrust in February 2013. At the time of submission of this abstract, the Kapiti SSE is still ongoing, but based on past behavior of Kapiti SSEs, they typically last 1 year, and release moment equivalent to a Mw 7.0. The previous Kapiti SSEs occurred in 2003 and 2008, confirming a 5 year recurrence interval for these SSEs. The central Hikurangi (Hawkes Bay region) SSE is the largest SSE observed to date on the portion of the subduction thrust beneath Hawke Bay, involving 1.5-2 cm of horizontal displacement of cGPS sites, and it is among the largest shallow (<15 km depth) SSEs ever observed on Earth. Most of the slip beneath Hawke Bay occurred within a 2 week period, but continued steady slip north of the main SSE region is ongoing (as of August 2013). In July, another shallow SSE occurred at the northern Hikurangi margin, where 4 Ocean Bottom Pressure recorders are deployed by Tohoku University to capture vertical seafloor deformation in Hikurangi SSEs. These 3 SSEs further demonstrate the remarkable diversity of slow slip behavior at the Hikurangi margin, particularly in terms of recurrence, depths, duration, and magnitudes. In addition to SSE activity, 2013 has also seen a swarm of earthquakes (up to ML 4.8) during the Hawkes Bay region SSE. On July 21, 2013, the largest earthquake to strike the Wellington region (Mw 6.5) since 1942 occurred on a NE-striking strike-slip fault at about 13 km focal depth, within the overriding plate beneath Cook Strait. The event was preceded by foreshocks reaching Mw 5.7 that had predominantly reverse focal mechanisms and somewhat deeper depths. We present evidence that this earthquake sequence may have been promoted by stress changes from the

  14. Alternate tube plugging criteria for steam generator tubes

    SciTech Connect

    Cueto-Felgueroso, C.; Aparicio, C.B.

    1997-02-01

    The tubing of the Steam Generators constitutes more than half of the reactor coolant pressure boundary. Specific requirements governing the maintenance of steam generator tubes integrity are set in Plant Technical Specifications and in Section XI of the ASME Boiler and Pressure Vessel Code. The operating experience of Steam Generator tubes of PWR plants has shown the existence of some types of degradatory processes. Every one of these has an specific cause and affects one or more zones of the tubes. In the case of Spanish Power Plants, and depending on the particular Plant considered, they should be mentioned the Primary Water Stress Corrosion Cracking (PWSCC) at the roll transition zone (RTZ), the Outside Diameter Stress Corrosion Cracking (ODSCC) at the Tube Support Plate (TSP) intersections and the fretting with the Anti-Vibration Bars (AVBs) or with the Support Plates in the preheater zone. The In-Service Inspections by Eddy Currents constitutes the standard method for assuring the SG tubes integrity and they permit the monitoring of the defects during the service life of the plant. When the degradation reaches a determined limit, called the plugging limit, the SG tube must be either repaired or retired from service by plugging. Customarily, the plugging limit is related to the depth of the defect. Such depth is typically 40% of the wall thickness of the tube and is applicable to any type of defect in the tube. In its origin, that limit was established for tubes thinned by wastage, which was the predominant degradation in the seventies. The application of this criterion for axial crack-like defects, as, for instance, those due to PWSCC in the roll transition zone, has lead to an excessive and unnecessary number of tubes being plugged. This has lead to the development of defect specific plugging criteria. Examples of the application of such criteria are discussed in the article.

  15. Reduced-vibration tube array

    DOEpatents

    Bruck, Gerald J.; Bartolomeo, Daniel R.

    2004-07-20

    A reduced-vibration tube array is disclosed. The array includes a plurality of tubes in a fixed arrangement and a plurality of damping members positioned within the tubes. The damping members include contoured interface regions characterized by bracing points that selectively contact the inner surface of an associated tube. Each interface region is sized and shaped in accordance with the associated tube, so that the damping member bracing points are spaced apart a vibration-reducing distance from the associated tube inner surfaces at equilibrium. During operation, mechanical interaction between the bracing points and the tube inner surfaces reduces vibration by a damage-reducing degree. In one embodiment, the interface regions are serpentine shaped. In another embodiment, the interface regions are helical in shape. The interface regions may be simultaneously helical and serpentine in shape. The damping members may be fixed within the associated tubes, and damping member may be customized several interference regions having attributes chosen in accordance with desired flow characteristics and associated tube properties.

  16. YouTube and 'psychiatry'.

    PubMed

    Gordon, Robert; Miller, John; Collins, Noel

    2015-12-01

    YouTube is a video-sharing website that is increasingly used to share and disseminate health-related information, particularly among younger people. There are reports that social media sites, such as YouTube, are being used to communicate an anti-psychiatry message but this has never been confirmed in any published analysis of YouTube clip content. This descriptive study revealed that the representation of 'psychiatry' during summer 2012 was predominantly negative. A subsequent smaller re-analysis suggests that the negative portrayal of 'psychiatry' on YouTube is a stable phenomenon. The significance of this and how it could be addressed are discussed. PMID:26755987

  17. Circular Scan Streak Tube Development

    NASA Technical Reports Server (NTRS)

    Nevin, S.

    1980-01-01

    A streak tube having circular scan was designed, built and tested. Continuous circular scan, easily derived from out of phase sine waves applied to the conventional deflection plates, permits the timing of pulses traveling long baselines. At the tube's output a circular array of 720 elements is scanned to provide 30 to 40 picosecond resolution. Initial difficulties with electron bombarded silicon arrays were circumvented by using microchannel plates within the streak tube to provide the needed electronic amplification and digital sensitivity and coupling the 720 element arrays to the electron beam by means of a phosphor on a fiber optics. Two ceramic body tubes with S-20 photocathodes were tested and delivered.

  18. 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.

  19. Robotic Booking Of Coolant Tubes

    NASA Technical Reports Server (NTRS)

    Wagner, Garret E.; Gutow, David A.; Gilbert, Jeffrey L.; Deily, David C.

    1994-01-01

    Robotic tube-booking subsystem proposed for use in automated manufacturing cell described in "Robotic Processing of Rocket-Engine Nozzles" (MFS-29927). Includes electric or pneumatic end effector that inspects gaps under guidance of control processor connected to robotic vision subsystem. After inspecting each gap, end effector books tubes in vicinity, then reinspects to ensure attainment of desired gap. Makes entire tube-gap area brazeable, without damage to tubes, with consistent results. In addition, robotic booking takes less time and costs less than manual booking.

  20. Learning from YouTube [Video Book

    ERIC Educational Resources Information Center

    Juhasz, Alexandra

    2011-01-01

    YouTube is a mess. YouTube is for amateurs. YouTube dissolves the real. YouTube is host to inconceivable combos. YouTube is best for corporate-made community. YouTube is badly baked. These are a few of the things Media Studies professor Alexandra Juhasz (and her class) learned about YouTube when she set out to investigate what actually happens…

  1. Controlling End-Grain Corrosion of Austenitic Stainless Steels

    NASA Astrophysics Data System (ADS)

    Chandra, Kamlesh; Kain, Vivekanand; Ganesh, Puppala

    2008-02-01

    SS 304L is widely used as a structural material in applications handling nitric acid such as nuclear fuel processing plants and nuclear waste management facilities. Bar, wire, and tubular products of this material are especially susceptible to end-grain corrosion in nitric acid environment. Such an attack takes place on the tubular and forged surfaces that are perpendicular to the hot-working direction and occurs as localized pitting type attack. This study shows that the possible reasons for the directional nature of end-grain attack are the manganese sulfide inclusions aligned along the hot-working direction and/or segregation of chromium along the flow lines during the fabrication stage itself. It has been shown in this study that controlled solution annealing, laser surface remelting, and weld overlay can be used to avoid/minimize end-grain corrosion. Different annealing heat-treatments were carried out on two heats of SS 304L tube and susceptibility to corrosion was measured by ASTM A 262 practice C and electrochemical potentiokinetic reactivation (EPR) test. Solution annealing at 950 °C for 90 min has been shown to increase the resistance to end-grain corrosion. Laser surface remelting using continuous wave CO2 laser under argon shield and weld deposition (overlay) using SS 308L material were done on the end faces of the tubes. These samples were completely resistant to end-grain corrosion in nitric acid environments.

  2. Infrared imaging of LED lighting tubes and fluorescent tubes

    NASA Astrophysics Data System (ADS)

    Siikanen, Sami; Kivi, Sini; Kauppinen, Timo; Juuti, Mikko

    2011-05-01

    The low energy efficiency of conventional light sources is mainly caused by generation of waste heat. We used infrared (IR) imaging in order to monitor the heating of both LED tube luminaires and ordinary T8 fluorescent tubes. The IR images showed clearly how the surface temperatures of the fluorescent tube ends quickly rose up to about +50...+70°C, whereas the highest surface temperatures seen on the LED tubes were only about +30...+40°C. The IR images demonstrated how the heat produced by the individual LED chips can be efficiently guided to the supporting structure in order to keep the LED emitters cool and hence maintain efficient operation. The consumed electrical power and produced illuminance were also recorded during 24 hour measurements. In order to assess the total luminous efficacy of the luminaires, separate luminous flux measurements were made in a large integrating sphere. The currently available LED tubes showed efficacies of up to 88 lm/W, whereas a standard "cool white" T8 fluorescent tube produced ca. 75 lm/W. Both lamp types gave ca. 110 - 130 lx right below the ceiling-mounted luminaire, but the LED tubes consume only 40 - 55% of the electric power compared to fluorescent tubes.

  3. Effect of the sequence of tube rolling in a tube bundle of a shell and tube heat exchanger on the stress-deformed state of the tube sheet

    NASA Astrophysics Data System (ADS)

    Tselishchev, M. F.; Plotnikov, P. N.; Brodov, Yu. M.

    2015-11-01

    Rolling the tube sheet of a heat exchanger with U-shaped tubes, as exemplified by the vapor cooler GP-24, was simulated. The simulation was performed using the finite element method with account of elas- tic-plastic properties of the tube and tube sheet materials. The simulation consisted of two stages; at the first stage, maximum and residual contact stress in the conjunction of a separate tube and the tube sheet was determined using the "equivalent sleeve" model; at the second stage, the obtained contact stress was applied to the hole surface in the tube sheet. Thus, different tube rolling sequences were simulated: from the center to the periphery of the tube sheet and from the periphery to the center along a spiral line. The studies showed that the tube rolling sequence noticeably influences the value of the tube sheet residual deflection for the same rolling parameters of separate tubes. Residual deflection of the tube sheet in different planes was determined. It was established that the smallest residual deflection corresponds to the tube rolling sequence from the periphery to the center of the tube sheet. The following dependences were obtained for different rolling sequences: maximum deformation of the tube sheet as a function of the number of rolled tubes, residual deformation of the tube sheet along its surface, and residual deflection of the tube sheet as a function of the rotation angle at the periphery. The preferred sequence of tube rolling for minimizing the tube sheet deformation is indicated.

  4. Analysis of ssDNA Gaps and DSBs in Genetically Unstable Yeast Cultures

    PubMed Central

    Peng, Jie; Raghuraman, M.K.; Feng, Wenyi

    2015-01-01

    DNA replication defects are an underlying cause of genome instability, which could stem from alterations in replication intermediates such as extensive single-stranded DNA (ssDNA). Under replication stress, ssDNA is a precursor of the ultimate double-strand breaks (DSBs). Indeed, mutations that render the cell incapable of mediating and protecting the replication forks produce ssDNA genome-wide at high frequency and cause lethality when encountering DNA damage or replication perturbation. Here we describe two related microarray-based methods to query genetically unstable yeast cultures, such as the mec1 and rad53 mutants. These mutants are defective in central protein kinases in the checkpoint pathway. To induce ssDNA and DSB formation in these mutants, we utilize hydroxyurea, a drug that causes nucleotide shortage in the cell. PMID:24906332

  5. Nasogastric tube syndrome induced by an indwelling long intestinal tube

    PubMed Central

    Sano, Naoki; Yamamoto, Masayoshi; Nagai, Kentaro; Yamada, Keiichi; Ohkohchi, Nobuhiro

    2016-01-01

    The nasogastric tube (NGT) has become a frequently used device to alleviate gastrointestinal symptoms. Nasogastric tube syndrome (NTS) is an uncommon but potentially life-threatening complication of an indwelling NGT. NTS is characterized by acute upper airway obstruction due to bilateral vocal cord paralysis. We report a case of a 76-year-old man with NTS, induced by an indwelling long intestinal tube. He was admitted to our hospital for treatment of sigmoid colon cancer. He underwent sigmoidectomy to release a bowel obstruction, and had a long intestinal tube inserted to decompress the intestinal tract. He presented acute dyspnea following prolonged intestinal intubation, and bronchoscopy showed bilateral vocal cord paralysis. The NGT was removed immediately, and tracheotomy was performed. The patient was finally discharged in a fully recovered state. NTS be considered in patients complaining of acute upper airway obstruction, not only with a NGT inserted but also with a long intestinal tube. PMID:27099450

  6. Explosive welding of a tube into a tube sheet

    DOEpatents

    Green, Sheryll C.; Linse, Vonne D.

    1978-10-03

    A cartridge containing an explosive charge is placed within a tube assembled within a tube sheet. The charge is detonated through use of a detonator cord containing a minimum but effective amount of explosive material. The cord is contained inside a tubular shield throughout most of its length within the cartridge. A small length of the cord extends beyond the tubular shield to contact and detonate the explosive charge in its rear portion near the cartridge base. The cartridge base is provided of substantial mass and thickness in respect to side and front walls of the cartridge to minimize bulging beyond the rear face of the tube sheet. For remote activation an electrically activated detonator of higher charge density than the cord is attached to the cord at a location spaced from the tube sheet, cartridge and tube.

  7. Nasogastric tube syndrome induced by an indwelling long intestinal tube.

    PubMed

    Sano, Naoki; Yamamoto, Masayoshi; Nagai, Kentaro; Yamada, Keiichi; Ohkohchi, Nobuhiro

    2016-04-21

    The nasogastric tube (NGT) has become a frequently used device to alleviate gastrointestinal symptoms. Nasogastric tube syndrome (NTS) is an uncommon but potentially life-threatening complication of an indwelling NGT. NTS is characterized by acute upper airway obstruction due to bilateral vocal cord paralysis. We report a case of a 76-year-old man with NTS, induced by an indwelling long intestinal tube. He was admitted to our hospital for treatment of sigmoid colon cancer. He underwent sigmoidectomy to release a bowel obstruction, and had a long intestinal tube inserted to decompress the intestinal tract. He presented acute dyspnea following prolonged intestinal intubation, and bronchoscopy showed bilateral vocal cord paralysis. The NGT was removed immediately, and tracheotomy was performed. The patient was finally discharged in a fully recovered state. NTS be considered in patients complaining of acute upper airway obstruction, not only with a NGT inserted but also with a long intestinal tube. PMID:27099450

  8. Piezoelectric Rotary Tube Motor

    NASA Technical Reports Server (NTRS)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert

    2011-01-01

    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  9. Traveling wave tube circuit

    NASA Technical Reports Server (NTRS)

    Connolly, D. J. (Inventor)

    1978-01-01

    A traveling wave tube (TWT) has a slow wave structure (SWS) which is severed into two or more sections. A signal path, connects the end of an SWS section to the beginning of the following SWS section. The signal path comprises an impedance matching coupler (IMC), followed by an isolator, a variable phase shifter, and a second IMC. The aggregate band pass characteristic of the components in the signal path is chosen to reject, or strongly attenuate, all frequencies outside the desired operating frequency range of the TWT and yet pass, with minimal attenuation in the forward direction, all frequencies within the desired operating frequency range. The isolator is chosen to reject, or strongly attenuate, waves, of all frequencies, which propagate in the backward direction. The aggregate phase shift characteristic of the components in the signal path is chosen to apply signal power to the beginning of the following SWS section with the phase angle yielding maximum efficiency.

  10. Drop tube research

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.

    1992-01-01

    This report covers the activities performed in the Drop Tube Study which The University of Alabama in Huntsville designed, fabricated and performed various low gravity experiments in materials processing from November 1, 1991 through October 30, 1992. During the performance of this contract the utilization of these ground-based containerless processing facilities has been instrumental in providing the opportunity to determine the feasibility of performing a number of solidification experiments in a simulated space environment, without the expense of a space-based experiment. A number of periodic reports have been given to the TCOR during the course of this contract hence this final report is meant only to summarize the many activities performed and not redundantly cover materials already submitted.

  11. Drop tube technical tasks

    NASA Technical Reports Server (NTRS)

    Workman, G. L.

    1986-01-01

    Criteria, using fundamental thermochemical dynamics, were developed to assist a scientist using the Drop Tube Facility in designing a good experiment. The types of parameters involved in designing the experiments include the type of furnace, the type of atmosphere, and in general which materials are better behaved than others as determined by past experience in the facility. One of the major advantages of the facility lies in its ability to provide large undercoolings in the cooling curve during the drops. A beginning was to consider the effect of oxygen and other gases upon the amount of undercooling observed. The starting point of the thermochemistry was given by Ellingham and later transformed into what is known as the Richardson Chart. The effect of surface oxidations upon the nucleation phenomena can be observed in each specimen.

  12. Characterizing and controlling the motion of ssDNA in a solid-state nanopore.

    PubMed

    Luan, Binquan; Martyna, Glenn; Stolovitzky, Gustavo

    2011-11-01

    Sequencing DNA in a synthetic solid-state nanopore is potentially a low-cost and high-throughput method. Essential to the nanopore-based DNA sequencing method is the ability to control the motion of a single-stranded DNA (ssDNA) molecule at single-base resolution. Experimental studies showed that the average translocation speed of DNA driven by a biasing electric field can be affected by ionic concentration, solvent viscosity, or temperature. Even though it is possible to slow down the average translocation speed, instantaneous motion of DNA is too diffusive to allow each DNA base to stay in front of a sensor site for its measurement. Using extensive all-atom molecular dynamics simulations, we study the diffusion constant, friction coefficient, electrophoretic mobility, and effective charge of ssDNA in a solid-state nanopore. Simulation results show that the spatial fluctuation of ssDNA in 1 ns is comparable to the spacing between neighboring nucleotides in ssDNA, which makes the sensing of a DNA base very difficult. We demonstrate that the recently proposed DNA transistor could potentially solve this problem by electrically trapping ssDNA inside the DNA transistor and ratcheting ssDNA base-by-base in a biasing electric field. When increasing the biasing electric field, we observed that the translocation of ssDNA changes from ratcheting to steady-sliding. The simulated translocation of ssDNA in the DNA transistor was theoretically characterized using Fokker-Planck analysis. PMID:22067161

  13. Integrated Composite Stiffener Structure (ICoSS) Concept for Planetary Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris

    2016-01-01

    Results from the design, manufacturing, and testing of a lightweight Integrated Composite Stiffened Structure (ICoSS) concept, intended for multi-mission planetary entry vehicles are presented. Tests from both component and full-scale tests for a typical Earth Entry Vehicle forward shell manufactured using the ICoSS concept are presented and advantages of the concept for the particular application of passive Earth Entry Vehicles over other structural concepts are discussed.

  14. Material modeling for multistage tube hydroforming process simulation

    NASA Astrophysics Data System (ADS)

    Saboori, Mehdi

    The Aerospace industries of the 21st century demand the use of cutting edge materials and manufacturing technology. New manufacturing methods such as hydroforming are relatively new and are being used to produce commercial vehicles. This process allows for part consolidation and reducing the number of parts in an assembly compared to conventional methods such as stamping, press forming and welding of multiple components. Hydroforming in particular, provides an endless opportunity to achieve multiple crosssectional shapes in a single tube. A single tube can be pre-bent and subsequently hydroformed to create an entire component assembly instead of welding many smaller sheet metal sections together. The knowledge of tube hydroforming for aerospace materials is not well developed yet, thus new methods are required to predict and study the formability, and the critical forming limits for aerospace materials. In order to have a better understanding of the formability and the mechanical properties of aerospace materials, a novel online measurement approach based on free expansion test is developed using a 3D automated deformation measurement system (AramisRTM) to extract the coordinates of the bulge profile during the test. These coordinates are used to calculate the circumferential and longitudinal curvatures, which are utilized to determine the effective stresses and effective strains at different stages of the tube hydroforming process. In the second step, two different methods, a weighted average method and a new hardening function are utilized to define accurately the true stress-strain curve for post-necking regime of different aerospace alloys, such as inconel 718 (IN 718), stainless steel 321 (SS 321) and titanium (Ti6Al4V). The flow curves are employed in the simulation of the dome height test, which is utilized for generating the forming limit diagrams (FLDs). Then, the effect of stress triaxiality, the stress concentration factor and the effective plastic

  15. Equations determine coiled tubing collapse pressure

    SciTech Connect

    Avakov, V.; Taliaferro, W.

    1995-07-24

    A set of equations has been developed for calculating pipe collapse pressure for oval tubing such as coiled tubing. When coiled tubing is placed onto a reel, the tubing is forced into an oval shape and never again returns to perfect roundness because the coiling process exceeds the plasticity limits of the tubing. Straightening the tubing for the trip into the well does not restore roundness. The consequence of this physical property is that all coiled tubing collapse pressure calculations should be made considering oval tubing, not round tubing. Tubing collapse can occur when formation pressure against the coiled tubing exceeds the collapse resistance inherent in the coiled tubing. As coiled tubing becomes more oval in shape, it becomes more oval in shape, it becomes more susceptible to collapse from outside pressure.

  16. Novel immunocytokine IL12-SS1 (Fv) inhibits mesothelioma tumor growth in nude mice.

    PubMed

    Kim, Heungnam; Gao, Wei; Ho, Mitchell

    2013-01-01

    Mesothelin is a glycosylphosphatidylinositol-anchored glycoprotein that is highly expressed on the cell surface of malignant mesothelioma. Monoclonal antibodies against mesothelin are being evaluated for the treatment of mesothelioma. Immunocytokines represent a novel class of armed antibodies. To provide an alternative approach to current mesothelin-targeted antibody therapies, we have developed a novel immunocytokine based on interleukin-12 (IL12) and the SS1 Fv specific for mesothelin. IL12 possesses potent anti-tumor activity in a wide variety of solid tumors. The newly-developed recombinant immunocytokine, IL12-SS1 (Fv), was produced in insect cells using a baculovirus-insect cell expression system. The SS1 single-chain Fv was fused to the C terminus of the p35 subunit of IL12 through a short linker (GSADGG). The single-chain IL12-SS1 (Fv) immunocytokine bound native mesothelin proteins on malignant mesothelioma (NCI-H226) and ovarian (OVCAR-3) cells as well as recombinant mesothelin on A431/H9 cells. The immunocytokine retained sufficient bioactivity of IL12 and significantly inhibited human malignant mesothelioma (NCI-H226) grown in the peritoneal cavity of nude mice and showed comparable anti-tumor activity to that of the SS1P immunotoxin. IL12-SS1 (Fv) is the first reported immunocytokine to mesothelin-positive tumors and may be an attractive addition to mesothelin-targeted cancer therapies. PMID:24260587

  17. DNA nanotubes and helical nanotapes via self-assembly of ssDNA-amphiphiles.

    PubMed

    Pearce, Timothy R; Kokkoli, Efrosini

    2015-01-01

    DNA nanotubes were created using molecular self-assembly of single-stranded DNA (ssDNA)-amphiphiles composed of a hydrophobic dialkyl tail and polycarbon spacer and a hydrophilic ssDNA headgroup. The nanotube structures were formed by bilayers of amphiphiles, with the hydrophobic components forming an inner layer that was shielded from the aqueous solvent by an outer layer of ssDNA. The nanotubes appeared to form via an assembly process that included transitions from twisted nanotapes to helical nanotapes to nanotubes. Amphiphiles that contained different ssDNA headgroups were created to explore the effect of the length and secondary structure of the ssDNA headgroup on the self-assembly behavior of the amphiphiles in the presence and absence of the polycarbon spacer. It was found that nanotubes could be formed using a variety of headgroup lengths and sequences. The ability to create nanotubes via ssDNA-amphiphile self-assembly offers an alternative to the other purely DNA-based approaches like DNA origami and DNA tile assembly for constructing these structures and may be useful for applications in drug delivery, biosensing, and electronics. PMID:25370121

  18. Promotion of plant growth by Pseudomonas fluorescens strain SS101 via novel volatile organic compounds.

    PubMed

    Park, Yong-Soon; Dutta, Swarnalee; Ann, Mina; Raaijmakers, Jos M; Park, Kyungseok

    2015-05-29

    Volatile organic compounds (VOCs) from plant growth-promoting rhizobacteria (PGPR) play key roles in modulating plant growth and induced systemic resistance (ISR) to pathogens. Despite their significance, the physiological functions of the specific VOCs produced by Pseudomonas fluorescens SS101 (Pf.SS101) have not been precisely elucidated. The effects of Pf.SS101 and its VOCs on augmentation of plant growth promotion were investigated in vitro and in planta. A significant growth promotion was observed in plants exposed Pf.SS101 under both conditions, suggesting that its VOCs play a key role in promoting plant growth. Solid-phase micro-extraction (SPME) and a gas chromatography-mass spectrophotometer (GC-MS) system were used to characterize the VOCs emitted by Pf.SS101 and 11 different compounds were detected in samples inoculated this bacterium, including 13-Tetradecadien-1-ol, 2-butanone and 2-Methyl-n-1-tridecene. Application of these compounds resulted in enhanced plant growth. This study suggests that Pf.SS101 promotes the growth of plants via the release of VOCs including 13-Tetradecadien-1-ol, 2-butanone and 2-Methyl-n-1-tridecene, thus increasing understanding of the role of VOCs in plant-bacterial inter-communication. PMID:25892516

  19. Intermittency and correlations in 200 GeV/nucleon S+S and S+Au collisions

    SciTech Connect

    Albrecht, R.; Antonenko, A.; Awes, T.C.; Berger, F.; Bloomer, M.A.; Bock, D.; Bock, R.; Claesson, G.; Clewing, G.; Dragon, L.; Eklund, A.; Fokin, S.; Franz, A.; Garpman, S.; Glasow, R.; Gustafsson, H.A.; Gutbrod, H.H.; Hartig, M.; He, X.; Hoelker, G.; Idh, J.; Ippolitov, M.; Jacobs, P.; Kampert, K.H.; Karadjev, K.; Kolb, B.W.; Lebedev, A.; Loehner, H.; Lund, I.; Manko, V.; Nikolaev, S.; Nystrand, J.; Obenshain, F.E.; Oskarsson, A.; Otterlund, I.; Peitzmann, T.; Plasil, F.; Poskanzer, A.M.; Purschke, M.; Ritter, H.; Roters, B.; Saini, S.; Santo, R.; Schmidt, H.R.; Soederstroem, K.; Sorensen, S.P.; Steffens, K.; Steinhaeuser, P.; Stenlund, E.; Stueken, D.; Vinogradov, A.; Young, G.R. Kurchatov Institute, Kurchatov Square, 123182 Moscow Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 University of Muenster, D-48149 Muenster Lawrence Berkeley Laboratory, Berkeley,

    1994-08-01

    We have studied one and two-dimensional scaled factorial moments in [sup 32]S+S and [sup 32]S+Au collisions at 200 GeV/nucleon in a high statistics electronic measurement at the CERN SPS using pad-readout streamer tubes. We observe no intermittency signal beyond that produced by folding the FRITIOF event generator with a detailed model of our detector. The systematic effects of detector response, two-track separation, and finite statistics in a factorial moment analysis are discussed in detail. Even though the observed signal contains measurable distortions due to these experimental effects, we show that we are sensitive to intermittency. As an alternative method, a two-particle correlation function analysis was applied to the same data to measure correlated particle production at small scales. We show that this method does not suffer as much as the factorial moment analysis does from distortions due to the limited two-track resolution of the detector. The correlation functions also agree with the predictions of FRITIOF filtered through our detector simulation, down to the limit of the two-track resolution. Since FRITIOF models nucleus-nucleus collisions by the superposition of nucleon-nucleon collisions, we conclude that there is no evidence in our data of the kinds of collective behavior predicted to give strong intermittency in heavy ion collisions.

  20. Transnasal Endoscopic Eustachian Tube Surgery.

    PubMed

    Dean, Marc; Lian, Timothy

    2016-10-01

    The purpose of this article is to give a contemporary review of transnasal endoscopic surgery for Eustachian tube disorders. The authors' perspective of the relevant anatomy, pathophysiology, and evaluation of Eustachian tube disorders as related to surgical intervention also is provided. PMID:27468637

  1. Tubing Cutter is Activated Hydraulically

    NASA Technical Reports Server (NTRS)

    Mcsmith, D. G.; Richardson, J. I.

    1983-01-01

    Hydraulically-actuated tubing cutter severs tubing when operator squeezes handle grip. "Gooseneck" extension enables cutter to be used in areas where accessiblity is limited. Cutter has potential as flight-line tool and is useful in automobile and fire rescue work.

  2. Gastrostomy feeding tube - pump - child

    MedlinePlus

    Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding set that matches the feeding pump (includes a feeding bag, drip chamber, roller clamp, ...

  3. Forming tool improves quality of tubing flares

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Punch and die set improves the quality of tubing flares for use with standard flared-tube fittings in high-pressure systems. It forges a dimensionally accurate flare in the tubing and forces more tubing material into the high-stress areas to improve the strength and tightness of the tubing connection.

  4. Building X-ray tube based irradiators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The construction of economical x-ray tube based irradiators in a variety of configurations is described using 1000 Watt x-ray tubes. Single tube, double tube, and four tube designs are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small s...

  5. A study of the efficiency of edible oils degraded in alkaline conditions by Pseudomonas aeruginosa SS-219 and Acinetobacter sp. SS-192 bacteria isolated from Japanese soil.

    PubMed

    Sugimori, Daisuke; Utsue, Tomohiro

    2012-03-01

    High lipid concentration contained in wastewater inhibits the activity of microorganisms in biological wastewater treatment systems such as activated sludge and methane fermentation. To reduce the inhibitory effects, microorganisms capable of efficiently degrading edible oils were screened from various environmental sources. From Japanese soil, we isolated 2 bacteria strains with high degradation abilities at an alkaline pH without consumption of biological oxygen demand (BOD) constituents. Acinetobacter sp. strain SS-192 and Pseudomonas aeruginosa strain SS-219 degraded 77.5 ± 0.6% and 89.5 ± 1.5%, respectively, of 3,000 ppm of mixed oil consisting of salad oil/lard/beef tallow (1/1/1, w/w/w) at 37°C and pH 9.0 in 24 h. Efficient degradation by the two strains occurred at pH 8-9 and 25-40°C. Strain SS-219 degraded lipids even at pH 3. The degradation rate of 3,000 ppm of salad oil, lard, and beef tallow by strain SS-192 was 79.9 ± 2.6%, 63.6 ± 1.9%, and 70.1 ± 1.2%, respectively, during a 24-h cultivation. The degradation rate of 3,000 ppm of salad oil, lard, and beef tallow by strain SS-219 was 82.3 ± 2.1%, 71.9 ± 2.2%, and 71.0 ± 1.1%, respectively, during a 24-h cultivation. After mixed oil degradation by both strains, the BOD value of the cell culture increased from 2,100 ppm to 3,200-4,000 ppm. The fact that neither strain utilizes BOD ingredients will be beneficial to pretreatment of methane fermentation systems such as upflow anaerobic sludge blanket reactors. In addition, the growth of usual heterotrophic microorganisms utilizing soluble BOD can be suppressed under alkaline pH. PMID:22805803

  6. VMD-SS: A graphical user interface plug-in to calculate the protein secondary structure in VMD program

    PubMed Central

    Yahyavi, Masoumeh; Falsafi-Zadeh, Sajad; Karimi, Zahra; Kalatarian, Giti; Galehdari, Hamid

    2014-01-01

    The investigation on the types of secondary structure (SS) of a protein is important. The evolution of secondary structures during molecular dynamics simulations is a useful parameter to analyze protein structures. Therefore, it is of interest to describe VMD-SS (a software program) for the identification of secondary structure elements and its trajectories during simulation for known structures available at the Protein Data Bank (PDB). The program helps to calculate (1) percentage SS, (2) SS occurrence in each residue, (3) percentage SS during simulation, and (4) percentage residues in all SS types during simulation. The VMD-SS plug-in was designed using TCL script and stride to calculate secondary structure features. Availability The database is available for free at http://science.scu.ac.ir/HomePage.aspx?TabID=13755 PMID:25258493

  7. Water-storage-tube systems. Final report

    SciTech Connect

    Hemker, P.

    1981-12-24

    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  8. Eddy current signal comparison for tube identification

    SciTech Connect

    Glass, S. W. E-mail: Ratko.Vojvodic@areva.com; Vojvodic, R. E-mail: Ratko.Vojvodic@areva.com

    2015-03-31

    Inspection of nuclear power plant steam generator tubes is required to justify continued safe plant operation. The steam generators consist of thousands of tubes with nominal diameters of 15 to 22mm, approximately 1mm wall thickness, and 20 to 30m in length. The tubes are inspected by passing an eddy current probe through the tubes from tube end to tube end. It is critical to know exactly which tube identification (row and column) is associated with each tube's data. This is controlled by a precision manipulator that provides the tube ID to the eddy current system. Historically there have been some instances where the manipulator incorrectly reported the tube ID. This can have serious consequences including lack of inspection of a tube, or if a pluggable indication is detected, the tube is likely to be mis-plugged thereby risking a primary to secondary leak.

  9. Eddy current signal comparison for tube identification

    NASA Astrophysics Data System (ADS)

    Glass, S. W.; Vojvodic, R.

    2015-03-01

    Inspection of nuclear power plant steam generator tubes is required to justify continued safe plant operation. The steam generators consist of thousands of tubes with nominal diameters of 15 to 22mm, approximately 1mm wall thickness, and 20 to 30m in length. The tubes are inspected by passing an eddy current probe through the tubes from tube end to tube end. It is critical to know exactly which tube identification (row and column) is associated with each tube's data. This is controlled by a precision manipulator that provides the tube ID to the eddy current system. Historically there have been some instances where the manipulator incorrectly reported the tube ID. This can have serious consequences including lack of inspection of a tube, or if a pluggable indication is detected, the tube is likely to be mis-plugged thereby risking a primary to secondary leak.

  10. Vidicon storage tube electrical input/output

    NASA Technical Reports Server (NTRS)

    Lipoma, P.

    1972-01-01

    Electrical data storage tube is assembled from standard vidicon tube using conventional amplification and control circuits. Vidicon storage tube is simple, inexpensive and has an erase and preparation time of less than 5 microseconds.

  11. Creep rupture properties of solution annealed and cold worked type 316 stainless steel cladding tubes

    NASA Astrophysics Data System (ADS)

    Mathew, M. D.; Latha, S.; Mannan, S. L.; Rodriguez, P.

    Austenitic stainless steels (mainly type 316 and its modifications) are used as fuel cladding materials in all current generation fast breeder reactors. For the Fast Breeder Test Reactor (FBTR) at Kalpakkam, modified type 316 stainless steel (SS) was chosen as the material for fuel cladding tubes. In order to evaluate the influence of cold work on the performance of the fuel element, the investigation was carried out on cladding tubes in three metallurgical conditions (solution annealed, ten percent cold worked, and twenty percent cold worked). The results indicate that: (1) the creep strength of type 316 SS cladding tube increases with increasing cold work; (2) the benificial effects of cold work are retained at almost all the test conditions investigated; and (3) the Larson Miller parameter analysis shows a two slope behavior for 20 PCW material suggesting that caution should be exercised in extrapolating the creep rupture life to stresses below 125 MPa. At very low stress levels, the LMP values fall below the values of the 10 PCW material.

  12. An improved DNA force field for ssDNA interactions with gold nanoparticles

    SciTech Connect

    Jiang, Xiankai; Huai, Ping; Fan, Chunhai; Song, Bo E-mail: bosong@sinap.ac.cn; Gao, Jun; Huynh, Tien; Zhou, Ruhong E-mail: bosong@sinap.ac.cn

    2014-06-21

    The widespread applications of single-stranded DNA (ssDNA) conjugated gold nanoparticles (AuNPs) have spurred an increasing interest in the interactions between ssDNA and AuNPs. Despite extensive studies using the most sophisticated experimental techniques, the detailed molecular mechanisms still remain largely unknown. Large scale molecular dynamics (MD) simulations can thus be used to supplement experiments by providing complementary information about ssDNA-AuNP interactions. However, up to now, all modern force fields for DNA were developed based on the properties of double-stranded DNA (dsDNA) molecules, which have hydrophilic outer backbones “protecting” hydrophobic inner nucleobases from water. Without the double-helix structure of dsDNA and thus the “protection” by the outer backbone, the nucleobases of ssDNA are directly exposed to solvent, and their behavior in water is very different from that of dsDNA, especially at the interface with nanoparticles. In this work, we have improved the force field of ssDNA for use with nanoparticles, such as AuNPs, based on recent experimental results and quantum mechanics calculations. With the new improved force field, we demonstrated that a poly(A) sequence adsorbed on a AuNP surface is much more stable than a poly(T) sequence, which is consistent with recent experimental observations. On the contrary, the current standard force fields, including AMBER03, CHARMM27, and OPLSAA, all gave erroneous results as compared to experiments. The current improved force field is expected to have wide applications in the study of ssDNA with nanomaterials including AuNPs, which might help promote the development of ssDNA-based biosensors and other bionano-devices.

  13. Toxicity of neurons treated with herbicides and neuroprotection by mitochondria-targeted antioxidant SS31.

    PubMed

    Reddy, Tejaswini P; Manczak, Maria; Calkins, Marcus J; Mao, Peizhong; Reddy, Arubala P; Shirendeb, Ulziibat; Park, Byung; Reddy, P Hemachandra

    2011-01-01

    The purpose of this study was to determine the neurotoxicity of two commonly used herbicides: picloram and triclopyr and the neuroprotective effects of the mitochondria-targeted antioxidant, SS31. Using mouse neuroblastoma (N2a) cells and primary neurons from C57BL/6 mice, we investigated the toxicity of these herbicides, and protective effects of SS1 peptide against picloram and triclopyr toxicity. We measured total RNA content, cell viability and mRNA expression of peroxiredoxins, neuroprotective genes, mitochondrial-encoded electron transport chain (ETC) genes in N2a cells treated with herbicides and SS31. Using primary neurons from C57BL/6 mice, neuronal survival was studied in neurons treated with herbicides, in neurons pretreated with SS31 plus treated with herbicides, neurons treated with SS31 alone, and untreated neurons. Significantly decreased total RNA content, and cell viability in N2a cells treated with picloram and triclopyr were found compared to untreated N2a cells. Decreased mRNA expression of neuroprotective genes, and ETC genes in cells treated with herbicides was found compared to untreated cells. Decreased mRNA expression of peroxiredoxins 1-6 in N2a cells treated with picloram was found, suggesting that picloram affects the antioxidant enzymes in N2a cells. Immunofluorescence analysis of primary neurons revealed that decreased neuronal branching and degenerating neurons in neurons treated with picloram and triclopyr. However, neurons pretreated with SS31 prevented degenerative process caused by herbicides. Based on these results, we propose that herbicides--picloram and triclopyr appear to damage neurons, and the SS31 peptide appears to protect neurons from herbicide toxicity. PMID:21318024

  14. Toxicity of Neurons Treated with Herbicides and Neuroprotection by Mitochondria-Targeted Antioxidant SS31

    PubMed Central

    Reddy, Tejaswini P.; Manczak, Maria; Calkins, Marcus J.; Mao, Peizhong; Reddy, Arubala P.; Shirendeb, Ulziibat; Park, Byung; Reddy, P. Hemachandra

    2011-01-01

    The purpose of this study was to determine the neurotoxicity of two commonly used herbicides: picloram and triclopyr and the neuroprotective effects of the mitochondria-targeted antioxidant, SS31. Using mouse neuroblastoma (N2a) cells and primary neurons from C57BL/6 mice, we investigated the toxicity of these herbicides, and protective effects of SS1 peptide against picloram and triclopyr toxicity. We measured total RNA content, cell viability and mRNA expression of peroxiredoxins, neuroprotective genes, mitochondrial-encoded electron transport chain (ETC) genes in N2a cells treated with herbicides and SS31. Using primary neurons from C57BL/6 mice, neuronal survival was studied in neurons treated with herbicides, in neurons pretreated with SS31 plus treated with herbicides, neurons treated with SS31 alone, and untreated neurons. Significantly decreased total RNA content, and cell viability in N2a cells treated with picloram and triclopyr were found compared to untreated N2a cells. Decreased mRNA expression of neuroprotective genes, and ETC genes in cells treated with herbicides was found compared to untreated cells. Decreased mRNA expression of peroxiredoxins 1–6 in N2a cells treated with picloram was found, suggesting that picloram affects the antioxidant enzymes in N2a cells. Immunofluorescence analysis of primary neurons revealed that decreased neuronal branching and degenerating neurons in neurons treated with picloram and triclopyr. However, neurons pretreated with SS31 prevented degenerative process caused by herbicides. Based on these results, we propose that herbicides—picloram and triclopyr appear to damage neurons, and the SS31 peptide appears to protect neurons from herbicide toxicity. PMID:21318024

  15. Detection of Root Surface Fractures with Swept-Source Optical Coherence Tomography (SS-OCT)

    PubMed Central

    Yoshioka, Toshihiko; Sakaue, Hitoshi; Ishimura, Hitomi; Suda, Hideaki; Sumi, Yasunori

    2013-01-01

    Abstract Objective: The purpose of this study was to compare optical coherence tomography (OCT) with the existing technologies, to assess its accuracy and utility in detecting vertical root fractures of extracted human teeth. Background data: The detection of root fractures in teeth that have undergone root canal treatment is challenging because of the great difficulty in differentiating these fractures from morphologic or radiographic anomalies. OCT methods are based on depth-resolved optical reflectivity and have been developed to reduce the invasiveness and radiation exposure inherent to other techniques. Methods: Twelve extracted human mandibular teeth (totaling 25 roots) that were free of caries, calculus, and root treatment were used, and assessed by microfocus computed tomography, the current gold standard for fracture detection. The ability of appropriately trained observers to detect root fractures using visual, microscopic, and swept-source OCT (SS-OCT) techniques were compared. micro-CT and SS-OCT produce three-dimensional images of the tooth from which to diagnose fractures, but CT scanning involves radiation exposure that is not required in SS-OCT. Results: Seventeen of the 25 roots were found to have fractures by microfocus CT. These findings were replicated by SS-OCT, which revealed fractures exhibiting identical origin, size, and angulation within the root. We found that SS-OCT gave results compatible to the gold standard technique, and that SS-OCT and microscopy were more effective for identifying root fractures than was visual observation alone. Conclusions: SS-OCT may represent a novel, noninvasive, noncontact and nonexposure alternative to the conventional methods used for assessing root fractures in teeth. PMID:23240873

  16. Flux tubes at finite temperature

    NASA Astrophysics Data System (ADS)

    Cea, Paolo; Cosmai, Leonardo; Cuteri, Francesca; Papa, Alessandro

    2016-06-01

    The chromoelectric field generated by a static quark-antiquark pair, with its peculiar tube-like shape, can be nicely described, at zero temperature, within the dual superconductor scenario for the QCD confining vacuum. In this work we investigate, by lattice Monte Carlo simulations of the SU (3) pure gauge theory, the fate of chromoelectric flux tubes across the deconfinement transition. We find that, if the distance between the static sources is kept fixed at about 0.76 fm˜eq 1.6/√{σ } and the temperature is increased towards and above the deconfinement temperature T c , the amplitude of the field inside the flux tube gets smaller, while the shape of the flux tube does not vary appreciably across deconfinement. This scenario with flux-tube "evaporation" above T c has no correspondence in ordinary (type-II) superconductivity, where instead the transition to the phase with normal conductivity is characterized by a divergent fattening of flux tubes as the transition temperature is approached from below. We present also some evidence about the existence of flux-tube structures in the magnetic sector of the theory in the deconfined phase.

  17. Comparison of Streak Tube Performance

    SciTech Connect

    Lerche, R A; Andrews, D S; Bell, P M; Griffiths, R L; Huey, A W; McDonald, J W; de Dios, G V

    2004-11-04

    The performance of four streak tubes in six streak camera configurations is reported. Evaluations were made as part of a search for a streak tube to replace the obsolete RCA C73435 used in the ICF Program's optical streak cameras. Characteristics measured include linearity, spatial and temporal resolution, line-spread function, contrast transfer ratio (CTR), and dynamic range. Tubes evaluated are the RCA C73435, Photonis P510, Photek ST-Y, and Hamamatsu N8059. The RCA C73435 was evaluated in three camera configurations: large format CCD coupled directly to the streak tube, CCD directly coupled to an image intensifier tube (IIT), and the original configuration with a smaller CCD lens coupled to the IIT output. The Photonis and Photek tubes were characterized in configurations where they were directly coupled to large format CCDs. Optimum spatial resolution is achieved when the IIT is removed. Maximum dynamic range requires a configuration where a single photoelectron from the photocathode produces a signal that is {approx}5 times the CCD read noise. The Photonis P510 tube with the E2V CCD forms a well-optimized streak camera system.

  18. Tube wall temperature monitoring technique

    SciTech Connect

    Granton, R.L.

    1985-07-01

    In 1977, Monsanto and Conoco undertook the construction of a new, modern technology ethylene plant at Chocolate Bayou, near Alvin, Texas. This plant included high severity cracking furnaces with potential tube wall temperatures considerably higher than any we had previously experienced. Furnace on-stream time between decokes, a factor in the economics of plant operation, was limited by tube wall temperature, thus requiring its accurate knowledge. Earlier work with other ethylene furnaces had also demonstrated our lack of knowledge concerning high temperature measurements in a furnace firebox environment. This had to change. An outside consultant was called upon to provide a threeday workshop on radiant tube temperature sensing. The workshop consisted of two days of formal training in the theory and practice of temperature measurement and one day of field training. This workshop was conducted at a site away from the plant. Approximately 20 engineers (manufacturing and technical groups) attended. The major topics covered by this workshop are as follows: radiant tube temperature sensing, radiation situation of radiant tubes, g.a. method: sample calculations, noncontact sensors: methods of specifying and purchasing, thermal imager strategies, calibration of noncontact sensors, avoiding problems with noncontact sensors, optical aids to radiant tube viewing, tube temperature management and its environmental implications, and contact temperature sensors.

  19. PEG tubes: dealing with complications.

    PubMed

    Malhi, Hardip; Thompson, Rosie

    A percutaneous endoscopic gastronomy tube can be used to deliver nutrition, hydration and medicines directly into the patient's stomach. Patients will require a tube if they are unable to swallow safely, putting them at risk of aspiration of food, drink and medicines into their lungs. It is vital that nurses are aware of the complications that may arise when caring for a patient with a PEG tube. It is equally important that nurses know how to deal with these complications or from where tc seek advice. This article provides a quick troubleshooting guide to help nurses deal with complications that can arise with PEG feeding. PMID:26016095

  20. Acoustical studies on corrugated tubes

    NASA Astrophysics Data System (ADS)

    Balaguru, Rajavel

    Corrugated tubes and pipes offer greater global flexibility combined with local rigidity. They are used in numerous engineering applications such as vacuum cleaner hosing, air conditioning systems of aircraft and automobiles, HVAC control systems of heating ducts in buildings, compact heat exchangers, medical equipment and offshore gas and oil transportation flexible riser pipelines. Recently there has been a renewed research interest in analyzing the flow through a corrugated tube to understand the underlying mechanism of so called whistling, although the whistling in such a tube was identified in early twentieth century. The phenomenon of whistling in a corrugated tube is interesting because an airflow through a smooth walled tube of similar dimensions will not generate any whistling tones. Study of whistling in corrugated tubes is important because, it not only causes an undesirable noise problem but also results in flow-acoustic coupling. Such a coupling can cause significant structural vibrations due to flow-acoustic-structure interaction. This interaction would cause flow-induced vibrations that could result in severe damage to mechanical systems having corrugated tubes. In this research work, sound generation (whistling) in corrugated tubes due to airflow is analyzed using experimental as well as Computational Fluid Dynamics-Large Eddy Simulation (CFD-LES) techniques. Sound generation mechanisms resulting in whistling have been investigated. The whistling in terms of frequencies and sound pressure levels for different flow velocities are studied. The analytical and experimental studies are carried out to understand the influence of various parameters of corrugated tubes such as cavity length, cavity width, cavity depth, pitch, Reynolds numbers and number of corrugations. The results indicate that there is a good agreement between theoretically calculated, computationally predicted and experimentally measured whistling frequencies and sound pressure levels

  1. Expansion tube test time predictions

    NASA Technical Reports Server (NTRS)

    Gourlay, Christopher M.

    1988-01-01

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

  2. Nonsteady Flow in Capillary Tubes

    NASA Astrophysics Data System (ADS)

    Hara, Ayako

    2000-03-01

    Surface phenomena in the field of electron devices and the problem of how long. It takes plants to absorb water during their growth in hydroponic cultivation is attraching the attention of riseachers. However, the related study of non-steady flow in capillary tubes has a number of issues that require investigation. In response to this situation, we made attempted to assess nonsteady fiow in capillary tubes, the liquid rise time and other issues, using a motion equation that takes factors including the friction force of the tube and the surface tension into consideration.

  3. Free vibration analysis for tube-in-tube tall buildings

    NASA Astrophysics Data System (ADS)

    Lee, Wen-Hae

    2007-06-01

    An approximate solution procedure is formulated for free vibration analysis of tube-in-tube tall buildings in this paper. The governing partial differential equation of motion is reduced to an ordinary differential equation with variable coefficients on the assumption that the transverse displacement is a harmonic vibration. A power-series solution which represents the mode shape function of tube-in-tube tall buildings is derived. Applying the boundary conditions yields the boundary value problem, from which the frequency equation is established and solved through a numerical process to determine the natural frequencies. Two numerical examples are performed and compared with results available in the published literature to show the accuracy of the proposed method. Care has been exercised to retain sufficient terms in power series in evaluating natural frequencies of accepted accuracy. The influences of the factors including flexural rigidity, mass per unit length and building height to the natural frequency are discussed. The method proposed herein enables one to calculate as an alternative the natural frequency of tube-in-tube tall buildings with good accuracy associated by calculators and hand, prior to use of the complicated computer programs.

  4. HL Canis Majoris in preoutburst and SS Cygni - The interoutburst disk instability

    NASA Technical Reports Server (NTRS)

    Mansperger, C. S.; Kaitchuck, R. H.; Garnavich, P. M.; Dinshaw, N.; Zamkoff, E.

    1994-01-01

    SS Cygni and HL Canis majoris were observed by IUE for three consecutive nights in November of 1992. During the first two nights, simultaneous photometric ground-based observations of SS Cyg were made at the Ball State University Observatory. Observations of SS Cyg and HL CMa were also obtained simultaneously with the 90-inch telescope at the Steward Observatory on the last two nights of the IUE run. These spectroscopic observations covered the wavelength range from 4100 to 5000 A, while the spectra taken with the short wavelength camera on IUE resulted in wavelength coverage from 1150 A to 1980 A. SS Cyg is a U Geminorum-type dwarf nova with an orbital period of 6.6 hr. Good simultaneous UV and optical orbital coverage was obtained for this system. HL CMa is a Z Camelopardalis-type dwarf nova with a mean outburst interval of 15 days. The American Association of Variable Star Observers (AAVSO) reports that this system was in outburst 4 days after the observing run. Therefore, HL CMa may have been in a preoutburst state during these observations. Optical spectra of HL CMa indicate a warm front passed through the outer disk four days before outburst, but no changes were seen in the UV spectra. Signs of a preoutburst state were observed to develop in SS Cyg, but no outburst occurred for another 30 days.

  5. ReSS: Resource Selection Service for National and Campus Grid Infrastructure

    NASA Astrophysics Data System (ADS)

    Mhashilkar, Parag; Garzoglio, Gabriele; Levshina, Tanya; Timm, Steve

    2010-04-01

    The Open Science Grid (OSG) offers access to around hundred Compute elements (CE) and storage elements (SE) via standard Grid interfaces. The Resource Selection Service (ReSS) is a push-based workload management system that is integrated with the OSG information systems and resources. ReSS integrates standard Grid tools such as Condor, as a brokering service and the gLite CEMon, for gathering and publishing resource information in GLUE Schema format. ReSS is used in OSG by Virtual Organizations (VO) such as Dark Energy Survey (DES), DZero and Engagement VO. ReSS is also used as a Resource Selection Service for Campus Grids, such as FermiGrid. VOs use ReSS to automate the resource selection in their workload management system to run jobs over the grid. In the past year, the system has been enhanced to enable publication and selection of storage resources and of any special software or software libraries (like MPI libraries) installed at computing resources. In this paper, we discuss the Resource Selection Service, its typical usage on the two scales of a National Cyber Infrastructure Grid, such as OSG, and of a campus Grid, such as FermiGrid.

  6. Architecture and ssDNA interaction of the Timeless-Tipin-RPA complex.

    PubMed

    Witosch, Justine; Wolf, Eva; Mizuno, Naoko

    2014-11-10

    The Timeless-Tipin (Tim-Tipin) complex, also referred to as the fork protection complex, is involved in coordination of DNA replication. Tim-Tipin is suggested to be recruited to replication forks via Replication Protein A (RPA) but details of the interaction are unknown. Here, using cryo-EM and biochemical methods, we characterized complex formation of Tim-Tipin, RPA and single-stranded DNA (ssDNA). Tim-Tipin and RPA form a 258 kDa complex with a 1:1:1 stoichiometry. The cryo-EM 3D reconstruction revealed a globular architecture of the Tim-Tipin-RPA complex with a ring-like and a U-shaped domain covered by a RPA lid. Interestingly, RPA in the complex adopts a horse shoe-like shape resembling its conformation in the presence of long ssDNA (>30 nucleotides). Furthermore, the recruitment of the Tim-Tipin-RPA complex to ssDNA is modulated by the RPA conformation and requires RPA to be in the more compact 30 nt ssDNA binding mode. The dynamic formation and disruption of the Tim-Tipin-RPA-ssDNA complex implicates the RPA-based recruitment of Tim-Tipin to the replication fork. PMID:25348395

  7. Structure/property (constitutive and dynamic strength/damage) characterization of additively manufactured 316L SS

    NASA Astrophysics Data System (ADS)

    Gray, G. T., III; Livescu, V.; Rigg, P. A.; Trujillo, C. P.; Cady, C. M.; Chen, S. R.; Carpenter, J. S.; Lienert, T. J.; Fensin, S.

    2015-09-01

    For additive manufacturing (AM), the certification and qualification paradigm needs to evolve as there exists no "ASTM-type" additive manufacturing certified process or AM-material produced specifications. Accordingly, utilization of AM materials to meet engineering applications requires quantification of the constitutive properties of these evolving materials in comparison to conventionally-manufactured metals and alloys. Cylinders of 316L SS were produced using a LENS MR-7 laser additive manufacturing system from Optomec (Albuquerque, NM) equipped with a 1kW Yb-fiber laser. The microstructure of the AM-316L SS is detailed in both the as-built condition and following heat-treatments designed to obtain full recrystallization. The constitutive behavior as a function of strain rate and temperature is presented and compared to that of nominal annealed wrought 316L SS plate. The dynamic damage evolution and failure response of all three materials was probed using flyer-plate impact driven spallation experiments at a peak stress of 4.5 GPa to examine incipient spallation response. The spall strength of AM-produced 316L SS was found to be very similar for the peak shock stress studied to that of annealed wrought or AM-316L SS following recrystallization. The damage evolution as a function of microstructure was characterized using optical metallography.

  8. ReSS: Resource Selection Service for National and Campus Grid Infrastructure

    SciTech Connect

    Mhashilkar, Parag; Garzoglio, Gabriele; Levshina, Tanya; Timm, Steve; /Fermilab

    2009-05-01

    The Open Science Grid (OSG) offers access to around hundred Compute elements (CE) and storage elements (SE) via standard Grid interfaces. The Resource Selection Service (ReSS) is a push-based workload management system that is integrated with the OSG information systems and resources. ReSS integrates standard Grid tools such as Condor, as a brokering service and the gLite CEMon, for gathering and publishing resource information in GLUE Schema format. ReSS is used in OSG by Virtual Organizations (VO) such as Dark Energy Survey (DES), DZero and Engagement VO. ReSS is also used as a Resource Selection Service for Campus Grids, such as FermiGrid. VOs use ReSS to automate the resource selection in their workload management system to run jobs over the grid. In the past year, the system has been enhanced to enable publication and selection of storage resources and of any special software or software libraries (like MPI libraries) installed at computing resources. In this paper, we discuss the Resource Selection Service, its typical usage on the two scales of a National Cyber Infrastructure Grid, such as OSG, and of a campus Grid, such as FermiGrid.

  9. Architecture and ssDNA interaction of the Timeless-Tipin-RPA complex

    PubMed Central

    Witosch, Justine; Wolf, Eva; Mizuno, Naoko

    2014-01-01

    The Timeless-Tipin (Tim-Tipin) complex, also referred to as the fork protection complex, is involved in coordination of DNA replication. Tim-Tipin is suggested to be recruited to replication forks via Replication Protein A (RPA) but details of the interaction are unknown. Here, using cryo-EM and biochemical methods, we characterized complex formation of Tim-Tipin, RPA and single-stranded DNA (ssDNA). Tim-Tipin and RPA form a 258 kDa complex with a 1:1:1 stoichiometry. The cryo-EM 3D reconstruction revealed a globular architecture of the Tim-Tipin-RPA complex with a ring-like and a U-shaped domain covered by a RPA lid. Interestingly, RPA in the complex adopts a horse shoe-like shape resembling its conformation in the presence of long ssDNA (>30 nucleotides). Furthermore, the recruitment of the Tim-Tipin-RPA complex to ssDNA is modulated by the RPA conformation and requires RPA to be in the more compact 30 nt ssDNA binding mode. The dynamic formation and disruption of the Tim-Tipin-RPA-ssDNA complex implicates the RPA-based recruitment of Tim-Tipin to the replication fork. PMID:25348395

  10. Differential Role of the T6SS in Acinetobacter baumannii Virulence

    PubMed Central

    Foucault-Grunenwald, Marie-Laure; Borges, Vitor; Charpentier, Xavier; Limansky, Adriana S.; Gomes, João Paulo; Viale, Alejandro M.; Salcedo, Suzana P.

    2015-01-01

    Gram-negative bacteria, such as Acinetobacter baumannii, are an increasing burden in hospitals worldwide with an alarming spread of multi-drug resistant (MDR) strains. Herein, we compared a type strain (ATCC17978), a non-clinical isolate (DSM30011) and MDR strains of A. baumannii implicated in hospital outbreaks (Ab242, Ab244 and Ab825), revealing distinct patterns of type VI secretion system (T6SS) functionality. The T6SS genomic locus is present and was actively transcribed in all of the above strains. However, only the A. baumannii DSM30011 strain was capable of killing Escherichia coli in a T6SS-dependent manner, unlike the clinical isolates, which failed to display an active T6SS in vitro. In addition, DSM30011 was able to outcompete ATCC17978 as well as Pseudomonas aeruginosa and Klebsiella pneumoniae, bacterial pathogens relevant in mixed nosocomial infections. Finally, we found that the T6SS of DSM30011 is required for host colonization of the model organism Galleria mellonella suggesting that this system could play an important role in A. baumannii virulence in a strain-specific manner. PMID:26401654

  11. Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia.

    PubMed

    Boufana, Belgees; Saïd, Yousra; Dhibi, Mokhtar; Craig, Philip S; Lahmar, Samia

    2015-12-01

    Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A.nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles. PMID:26314229

  12. Previously unknown and highly divergent ssDNA viruses populate the oceans

    PubMed Central

    Labonté, Jessica M; Suttle, Curtis A

    2013-01-01

    Single-stranded DNA (ssDNA) viruses are economically important pathogens of plants and animals, and are widespread in oceans; yet, the diversity and evolutionary relationships among marine ssDNA viruses remain largely unknown. Here we present the results from a metagenomic study of composite samples from temperate (Saanich Inlet, 11 samples; Strait of Georgia, 85 samples) and subtropical (46 samples, Gulf of Mexico) seawater. Most sequences (84%) had no evident similarity to sequenced viruses. In total, 608 putative complete genomes of ssDNA viruses were assembled, almost doubling the number of ssDNA viral genomes in databases. These comprised 129 genetically distinct groups, each represented by at least one complete genome that had no recognizable similarity to each other or to other virus sequences. Given that the seven recognized families of ssDNA viruses have considerable sequence homology within them, this suggests that many of these genetic groups may represent new viral families. Moreover, nearly 70% of the sequences were similar to one of these genomes, indicating that most of the sequences could be assigned to a genetically distinct group. Most sequences fell within 11 well-defined gene groups, each sharing a common gene. Some of these encoded putative replication and coat proteins that had similarity to sequences from viruses infecting eukaryotes, suggesting that these were likely from viruses infecting eukaryotic phytoplankton and zooplankton. PMID:23842650

  13. Dose-related growth deficits in LS but not SS mice prenatally exposed to alcohol.

    PubMed

    Gilliam, D M; Kotch, L E

    1996-01-01

    Genetically based alcohol sensitivity may influence the severity of alcohol-related birth defects. To examine this question, measures of growth and survival were examined in offspring of the alcohol sensitive Long-Sleep (LS) and alcohol-resistant Short-Sleep (SS) mouse lines following prenatal ethanol exposure. Pregnant LS and SS mice received an ethanol dose of either 6 or 8 g/kg/day from days 7 through 18 of pregnancy. Control groups received a maltose-dextran solution made isocaloric to the 8 g/kg/day dose. Ethanol and maltose-dextrin solutions were administered as split doses, 6 h apart, via gavage. Nonintubated lab chow control groups were also included for both mouse lines. Offspring were fostered at birth to lactating mice of an outbred stock. Pregnancy was longer for ethanol-treated LS dams compared to maltose-dextrin and lab chow LS control groups, whereas pregnancy length for ethanol-treated SS dams was similar to SS controls. Prenatal ethanol exposure resulted in dose-related growth deficits in LS but not in SS litters. Line differences in postnatal growth deficits in response to prenatal alcohol exposure suggest maternal or fetal alcohol sensitivity influence alcohol-related birth defects. PMID:8837934

  14. Previously unknown and highly divergent ssDNA viruses populate the oceans.

    PubMed

    Labonté, Jessica M; Suttle, Curtis A

    2013-11-01

    Single-stranded DNA (ssDNA) viruses are economically important pathogens of plants and animals, and are widespread in oceans; yet, the diversity and evolutionary relationships among marine ssDNA viruses remain largely unknown. Here we present the results from a metagenomic study of composite samples from temperate (Saanich Inlet, 11 samples; Strait of Georgia, 85 samples) and subtropical (46 samples, Gulf of Mexico) seawater. Most sequences (84%) had no evident similarity to sequenced viruses. In total, 608 putative complete genomes of ssDNA viruses were assembled, almost doubling the number of ssDNA viral genomes in databases. These comprised 129 genetically distinct groups, each represented by at least one complete genome that had no recognizable similarity to each other or to other virus sequences. Given that the seven recognized families of ssDNA viruses have considerable sequence homology within them, this suggests that many of these genetic groups may represent new viral families. Moreover, nearly 70% of the sequences were similar to one of these genomes, indicating that most of the sequences could be assigned to a genetically distinct group. Most sequences fell within 11 well-defined gene groups, each sharing a common gene. Some of these encoded putative replication and coat proteins that had similarity to sequences from viruses infecting eukaryotes, suggesting that these were likely from viruses infecting eukaryotic phytoplankton and zooplankton. PMID:23842650

  15. Gastrostomy feeding tube - pump - child

    MedlinePlus

    ... supplies: Feeding pump (electronic or battery powered) Feeding set that matches the feeding pump (includes a feeding ... drip chamber, roller clamp, and long tube) Extension set, for a Bard Button or MIC-KEY (this ...

  16. Tube-wave seismic imaging

    DOEpatents

    Korneev, Valeri A [LaFayette, CA

    2009-05-05

    The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.

  17. Thermal stresses in composite tubes

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.

    1986-01-01

    This paper summarizes work to determine the thermally-induced stresses and deformations in specially-constructed angle-ply composite tubes subjected to a uniform temperature change relative to their stress-free cure state. The tubes are designed for application to space structures and have high axial stiffness. Four angle-ply designs are examined in an effort to determine which design might have the most favorable thermally-induced response. A planar elasticity solution is used, the solution being valid away from the ends of the tube. Of the four designs considered, none has any particular advantage as far as stress levels are concerned. However, despite the fact that the tube wall is a balanced laminate, one design exhibits a significant amount of thermally-induced twist.

  18. Tube-wave seismic imaging

    DOEpatents

    Korneev, Valeri A.; Bakulin, Andrey

    2009-10-13

    The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.

  19. Technique for joining metal tubing

    NASA Technical Reports Server (NTRS)

    Wright, H. W.

    1976-01-01

    Uniform wall thickness and uninterrupted heat transfer is achieved by using shaped metal insert as wall material for joint. Insert acts as support during brazing, after which excess material is ground away to bring joint to original tubing size.

  20. NEI You Tube Videos: Amblyopia

    MedlinePlus Videos and Cool Tools

    ... Funding Division of Extramural Activities Division of Extramural Science Programs Funding Opportunity Announcements Funding Mechanisms Supported by ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI ...

  1. Photomultiplier tube gain regulating system

    DOEpatents

    Johnson, Wayne F.

    1976-01-01

    This invention relates to an improved system for regulating the gain of a photomultiplier tube, and was designed for use with the photomultiplier tubes of a GeMSAEC fast analyzers. It has the following advantages over the prior system: noise is virtually eliminated; sample analysis can begin after 3 to 4 revolutions of the rotor; fluorescent and light scattering solutions can be used as a reference; and the reference solution can be in any cuvette on the rotor.

  2. SlyA Regulates Type III Secretion System (T3SS) Genes in Parallel with the T3SS Master Regulator HrpL in Dickeya dadantii 3937

    PubMed Central

    Zou, Lifang; Zeng, Quan; Lin, Haiping; Gyaneshwar, Prasad

    2012-01-01

    The hypersensitive response and pathogenicity (hrp) genes of Dickeya dadantii 3937 encode a type III secretion system (T3SS) which is essential for its full virulence. Previous studies of the T3SS regulation in D. dadantii 3937 revealed that the expression of the hrp genes is regulated by a master regulator, HrpL, through the HrpX-HrpY-HrpS-HrpL and GacS-GacA-rsmB-RsmA pathways. In this work, we identified a novel regulator of the SlyA/MarR family, SlyA, which regulates hrp genes of the HrpL regulon in parallel with HrpL in D. dadantii. SlyA regulates the T3SS in a two-tier manner. It negatively regulates the expression of hrpL by downregulating hrpS and upregulating rsmA. Interestingly, concomitant with its downregulation of the hrpL, SlyA positively regulates the expression of hrpA and hrpN, two hrp genes located in the HrpL regulon. In contrast to Pectobacterium carotovorum, the expression of slyA is not controlled by ExpR and ExpI in D. dadantii 3937. We further show that SlyA is involved in controlling swimming motility and pellicle formation in D. dadantii 3937. PMID:22267675

  3. Tube wall thickness measurement apparatus

    DOEpatents

    Lagasse, Paul R.

    1987-01-01

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  4. Tube wall thickness measurement apparatus

    DOEpatents

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  5. Search for Gamma Ray Line Emission from SS433 in the SMM GRS Data Base

    NASA Astrophysics Data System (ADS)

    Geller, H. A.; Geldzahler, B. J.

    1992-05-01

    Gamma ray spectra of SS433 obtained by the Gamma Ray Spectrometer aboard the Solar Maximum Mission satellite during 1980-1989 were examined for evidence of Doppler shifted line emission. The main emphasis, using both 3-day and 9-day integrations, was on the 1.368 MeV magnesium-24 line suggested by Lamb et al. (1983, Nature, 305,37). This work completes the examination of the SMM data base on SS433, augmenting and extending the study of Geldzahler et al. (1989, Ap.J., 342, 1123). The results are examined in the context of the models of gamma ray emission from SS433 published by Ramaty et al. (1984, Ap.J., 283, L13) and Boyd et al. (1984, Ap.J.,276, L9). This work was supported by NASA grant NAS 5-26954 at the Institute for Computational Sciences and Informatics, George Mason University.

  6. SWIFT Observations of a Far UV Luminosity Component in SS433

    NASA Technical Reports Server (NTRS)

    Cannizzo, J. K.; Boyd, P. T.; Dolan, J. F.

    2007-01-01

    SS433 is a binary system showing relativistic Doppler shifts in its two sets of emission lines. The origin of its UV continuum is not well established. We observed SS433 to determine the emission mechanism responsible for its far UV spectrum. The source was observed at several different phases of both its 13 d orbital period and 162.5 d precession period using the UVOT and XRT detector systems on Swift. The far UV spectrum down to 1880 Angstrom lies significantly above the spectral flux distribution predicted by extrapolating the reddened blackbody continuum that fits the spectrum above 3500 Angstroms. The intensity of the far UV flux varies over a period of days and the variability is correlated with the variability of the soft X-ray flux from the source. An emission mechanism in addition to those previously detected in the optical and X-ray regions must exist in the far UV spectrum of SS433.

  7. Resistance of superhydrophobic and oleophobic surfaces to varied temperature applications on 316L SS

    NASA Astrophysics Data System (ADS)

    Shams, Hamza; Basit, Kanza; Saleem, Sajid; Siddiqui, Bilal A.

    316L SS also called Marine Stainless Steel is an important material for structural and marine applications. When superhydrophobic and oleophobic coatings are applied on 316L SS it shows significant resistance to wear and corrosion. This paper aims to validate the coatings manufacturer's information on optimal temperature range and test the viability of coating against multiple oil based cleaning agents. 316L SS was coated with multiple superhydrophic and oleohobic coatings and observed under SEM for validity of adhesion and thickness and then scanned under FFM to validate the tribological information. The samples were then dipped into multiple cleaning agents maintained at the range of operating temperatures specified by the manufacturer. Coating was observed for deterioration over a fixed time intervals through SEM and FFM. A comparison was drawn to validate the most critical cleaning agent and the most critical temperature at which the coating fails to leave the base substrate exposed to the environment.

  8. Plasmon-driven dimerization via S-S chemical bond in an aqueous environment

    PubMed Central

    Cui, Lin; Wang, Peijie; Chen, Xiaowei; Fang, Yurui; Zhang, Zhenglong; Sun, Mengtao

    2014-01-01

    The surface-enhanced Raman scattering (SERS) spectra of thioanisole are experimentally investigated in an electrochemical environment in this study. Two Raman peaks, which depend strongly not only on electric potential but also on the local surface plasmon resonances (LSPR), have been observed. Theoretical calculations reveal that thioanisole is first dissociated from thiophenol via the S-CH3 bond; plasmons then drive the dimerisation of thiophenol via the S-S bond, which is strongly potential dependent. One Raman peak corresponds to the S-S vibrational mode of the thiophenol dimer, and the other corresponds to the asymmetric C-C stretching modes of the benzenyl of the thiophenol dimer. The potential-dependent two Raman modes is the potential-dependent dimerisation dynamics of thiophenol via the S-S bond. Our experimental findings provide insight into the structural elucidation of adsorbed molecules and molecular surface reaction dynamics. PMID:25427897

  9. Combinatorial gene editing in mammalian cells using ssODNs and TALENs

    NASA Astrophysics Data System (ADS)

    Strouse, Bryan; Bialk, Pawel; Niamat, Rohina A.; Rivera-Torres, Natalia; Kmiec, Eric B.

    2014-01-01

    The regulation of gene editing is being elucidated in mammalian cells and its potential as well as its limitations are becoming evident. ssODNs carry out gene editing by annealing to their complimentary sequence at the target site and acting as primers for replication fork extension. To effect a genetic change, a large amount of ssODN molecules must be introduced into cells and as such induce a Reduced Proliferation Phenotype (RPP), a phenomenon in which corrected cells do not proliferate. To overcome this limitation, we have used TAL-Effector Nucleases (TALENs) to increase the frequency, while reducing the amount of ssODN required to direct gene correction. This strategy resolves the problem and averts the serious effects of RPP. The efficiency of gene editing can be increased significantly if cells are targeted while they progress through S phase. Our studies define new reaction parameters that will help guide experimental strategies of gene editing.

  10. Influence of consolidation method on structure/properties of rapidly solidified Type 304 SS powders

    SciTech Connect

    Flinn, J.E.; Korth, G.E.; Wright, R.N.

    1988-01-01

    The structure/properties of consolidated, centrifugally atomized (CA) Type 304 SS powders containing approx.8 appM helium entrapped during powder processing were evaluated. Three powder consolidation methods were used in the study: hot extrusion, hot isostatic pressing (HIPping), and dynamic (using explosives). In addition, cold-rolled 50% HIPped material was included in the evaluation. The four forms of consolidated powders were fully dense and possessed good bond strengths. The bond strength of the HIPped powders was the lowest. The consolidated materials were subjected to 1 h heat treatments and their grain growth, tensile, and creep behaviors were compared with those of wrought ingot metallurgy Type 304 SS materials. Grain growth of the CA Type 304 SS consolidated powders was substantially lower than for the wrought material. Similarly, significant strengthening was observed for the powder materials. The apparent microstructure stability and strengthening observed for the consolidated powder materials is attributed to the entrapped helium. 5 figs., 4 tabs.

  11. Hydration of ds-DNA and ss-DNA by Neutron Quasielastic Scattering

    PubMed Central

    Bastos, M.; Castro, V.; Mrevlishvili, G.; Teixeira, J.

    2004-01-01

    Quasielastic neutron scattering measurements were performed in hydrated samples of ds-DNA and ss-DNA. The samples were hydrated in a high relative humidity atmosphere, and their final water content was 0.559 g H2O/g ds-DNA and 0.434 g H2O/g ss-DNA. The measurements were performed at 8 and 5.2 Å for the ds-DNA sample, and at 5.2 Å for the ss-DNA sample. The temperature was in both cases 298 K. Analysis of the obtained data indicates that in the ds-DNA sample we can distinguish two types of protons—those belonging to water molecules strongly attached to the ds-DNA surface and another fraction belonging to water that diffuses isotropically in a sphere of radius 2.8 Å, with a local diffusion coefficient of 2.2 × 10−5 cm2 s−1. For ss-DNA, on the other hand, no indication was found of motionally restricted or confined water. Further, the fraction of protons strongly attached to the ds-DNA surface corresponds to 0.16 g H2O/g ds-DNA, which equals the amount of water that is released by ds-DNA upon thermal denaturation, as studied by one of us (G.M.) by differential scanning calorimetry. This value also equals the difference between the critical hydration values of ds-DNA and ss-DNA, also determined by DSC. These results represent, thus, a completely independent measurement of water characteristics and behavior in ds- and ss-DNA at critical hydration values, and therefore substantiate the previous suggestions/conclusions of the results obtained by calorimetry. PMID:15189878

  12. Binding hot-spots in an antibody-ssDNA interface: a molecular dynamics study.

    PubMed

    Wang, Yeng-Tseng; Lee, Wen-Jay

    2012-10-30

    Simulating antigen-antibody interactions is essential for elucidating antigen-antibody mechanics. Proteins interactions are vital for elucidating antibody-ssDNA associations in immunology. Therefore, this study investigated the dissociation of the human systemic lupus erythematosus antibody-ssDNA complex structure. Dissociation (i.e. the distance between the center of mass of the ssDNA and the antibody) is also studied using the potential of mean force calculations based on molecular dynamics and the explicit water model. The MM-PBSA method is also used to prove our dissociation simulations. With 605 nanosecond molecular dynamics simulations, the results indicate that the 8 residues (i.e. Gly44 (HCDR2), Asn54 (HCDR2), Arg98 (HCDR3), Tyr100 (HCDR3), Asp101 (HCDR3), Tyr32 (LCDR1), Tyr49 (LCDR2) and Asn50 (LCDR2)), and the five inter-protein molecular hydrogen bonds may profoundly impact the antibody-ssDNA interaction, a finding which may be useful for protein engineering of this antibody-ssDNA structure. Experimental binding affinity of this antibody-ssDNA complex equals 7.00 kcal mol(-1). Our dissociation binding affinity is 7.96 ± 0.33 kcal mol(-1) and MM-PBSA binding affinity is 9.12 ± 1.65 kcal mol(-1), which is close to the experimental value. Additionally, the 8 residues Gly44 (HCDR2), Asn54 (HCDR2), Arg98 (HCDR3), Tyr100 (HCDR3), Asp101 (HCDR3), Tyr32 (LCDR1), Tyr49 (LCDR2) and Asn50 (LCDR2) may play a more significant role in developing bioactive antibody analogues. PMID:23079742

  13. Chandra HETG Spectra of SS Cyg and U Gem in Quiescence and Outburst

    SciTech Connect

    Mauche, C W; Wheatley, P J; Long, K S; Raymond, J C; Szkody, P

    2004-09-24

    Chandra HETG spectra of the prototypical dwarf novae SS Cyg and U Gem in quiescence and outburst are presented and discussed. When SS Cyg goes into outburst, it becomes dimmer in hard X-rays and displays a dramatic shift in its relative line strengths, whereas when U Gem goes into outburst, it becomes brighter in hard X-rays and displays only a minor shift in its relative line strengths. In both systems, the emission lines become significantly broader in outburst, signaling the presence of high velocity gas either in Keplerian orbits around the white dwarf or flowing outward from the system.

  14. Scalable and reusable emulator for evaluating the performance of SS7 networks

    NASA Astrophysics Data System (ADS)

    Lazar, Aurel A.; Tseng, Kent H.; Lim, Koon Seng; Choe, Winston

    1994-04-01

    A scalable and reusable emulator was designed and implemented for studying the behavior of SS7 networks. The emulator design was largely based on public domain software. It was developed on top of an environment supported by PVM, the Parallel Virtual Machine, and managed by OSIMIS-the OSI Management Information Service platform. The emulator runs on top of a commercially available ATM LAN interconnecting engineering workstations. As a case study for evaluating the emulator, the behavior of the Singapore National SS7 Network under fault and unbalanced loading conditions was investigated.

  15. True logarithmic amplification of frequency clock in SS-OCT for calibration

    PubMed Central

    Liu, Bin; Azimi, Ehsan; Brezinski, Mark E.

    2011-01-01

    With swept source optical coherence tomography (SS-OCT), imprecise signal calibration prevents optimal imaging of biological tissues such as coronary artery. This work demonstrates an approach using a true logarithmic amplifier to precondition the clock signal, with the effort to minimize the noises and phase errors for optimal calibration. This method was validated and tested with a high-speed SS-OCT. The experimental results manifest its superior ability on optimization of the calibration and improvement of the imaging performance. Particularly, this hardware-based approach is suitable for real-time calibration in a high-speed system where computation time is constrained. PMID:21698036

  16. 27 CFR 41.35 - Cigarette tubes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following...

  17. 27 CFR 41.35 - Cigarette tubes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following...

  18. 27 CFR 40.352 - Cigarette tubes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette...

  19. 27 CFR 40.352 - Cigarette tubes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette...

  20. 27 CFR 41.35 - Cigarette tubes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following...

  1. 27 CFR 41.35 - Cigarette tubes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following...

  2. 27 CFR 40.352 - Cigarette tubes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette...

  3. 27 CFR 40.352 - Cigarette tubes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette...

  4. 27 CFR 40.352 - Cigarette tubes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette...

  5. 27 CFR 41.35 - Cigarette tubes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following...

  6. Gage tests tube flares quickly and accurately

    NASA Technical Reports Server (NTRS)

    Griffin, F. D.

    1966-01-01

    Flared tube gage with a test cone that is precisely made with a tapering surface to complement the tube flare is capable of determining the accuracy of a tube flare efficiently and economically. This device should improve the speed, efficiency, and accuracy of tube flare inspections.

  7. Rounding And Aligning Tubes For Butt Welding

    NASA Technical Reports Server (NTRS)

    Burley, Richard H.; Burow, Glenn H.

    1990-01-01

    Easy-to-use tool helps to ensure solid, reliable joint. Tool similar to automobile-tailpipe expander corrects out-of-roundness in tubes before butt-welded and holds tubes in position during welding. Two tubes rounded and aligned with each other by expansion shoes. After use, shoes retracted so tool withdrawn, even through tube narrower than its mate.

  8. Osmotic regulation of seamless tube growth.

    PubMed

    Schottenfeld-Roames, Jodi; Ghabrial, Amin S

    2013-02-01

    Most organs are composed of tubes of differing cellular architectures, including intracellular 'seamless' tubes. Two studies examining the morphogenesis of the seamless tubes formed by the excretory canal cell in Caenorhabditis elegans reveal a previously unappreciated role for osmoregulation of tubulogenesis: hyperosmotic shock recruits canalicular vesicles to the lumenal membrane to promote seamless tube growth. PMID:23377027

  9. Expander for Thin-Wall Tubing

    NASA Technical Reports Server (NTRS)

    Pessin, R.

    1983-01-01

    Tool locally expands small-diameter tubes. Tube expander locally expands and deforms tube: Compressive lateral stress induced in elastomeric sleeve by squeezing axially between two metal tool parts. Adaptable to situations in which tube must have small bulge for mechanical support or flow control.

  10. Tube surfaces in pseudo-Galilean space

    NASA Astrophysics Data System (ADS)

    Dede, Mustafa

    2016-03-01

    In this paper, we introduce the tube surfaces in pseudo-Galilean 3-space. We classify the tube surfaces into two types according to the spine curve which generates the tube surface in pseudo-Galilean space. Moreover, we show that both types of tube surfaces are spacelike surfaces. Then, we begin to study the local geometry of the tube surfaces. We obtain the first and second fundamental forms of the tube surfaces. In addition, we investigate the Gauss and mean curvatures of the tube surfaces in pseudo-Galilean space.

  11. Characterization of mixed monolayers of phosphatidylcholine and a dicationic gemini surfactant SS-1 with a langmuir balance: effects of DNA.

    PubMed Central

    Matti, V; Säily, J; Ryhänen, S J; Holopainen, J M; Borocci, S; Mancini, G; Kinnunen, P K

    2001-01-01

    Monolayers of a cationic gemini surfactant, 2,3-dimethoxy-1,4-bis(N-hexadecyl-N;N-dimethyl-ammonium)butane dibromide (abbreviated as SS-1) and its mixtures with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were studied using a Langmuir balance. More specifically, we measured the force-area (pi-A) curves and determined the elastic area compressibility modulus (C) as a function of lateral packing pressure and the mole fraction of the cationic lipid (X(SS-1)), with and without DNA in the subphase. Both SS-1 and POPC exhibited smooth compression isotherms, indicating their monolayers to be in the liquid expanded state. Even low contents (X(SS-1) < 0.05) of SS-1 in a POPC monolayer condensed the film dramatically, up to 20% at 30 mN/m. This effect is suggested to reflect reorientation of the P(-)-N(+) dipole of the POPC headgroup. Accordingly, the magnitude of the condensing effect diminishes with X(SS-1) and is not observed for mixed films of dioleoylglycerol and SS-1. Reorientation of the P(-)-N(+) dipole is further supported by the pronounced increase in monolayer dipole potential psi due to SS-1. The presence of DNA in the subphase affected the mixed POPC/SS-1 monolayers differently depending on the constituent lipid stoichiometry as well as on the DNA/SS-1 charge ratio. At a DNA concentration of 0.63 microM (in base pairs) condensation of neat POPC monolayers was evident, and this effect remained up to X(SS-1) < 0.5, corresponding to DNA/SS-1 charge ratio of 1.25. An expansion due to DNA, evident as an increase in DeltaA/molecule, was observed at X(SS-1) > 0.5. At a higher concentration of DNA (1.88 microM base pairs) in the subphase corresponding to DNA/SS-1 charge ratio of 3.75 at X(SS-1) = 0.5, condensation was observed at all values of X(SS-1). PMID:11566784

  12. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Arch tubes, water bar tubes, circulators and... MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.61 Arch tubes, water bar tubes... water bar tubes shall thoroughly be cleaned mechanically, washed, and inspected. Circulators and...

  13. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Arch tubes, water bar tubes, circulators and... MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.61 Arch tubes, water bar tubes... water bar tubes shall thoroughly be cleaned mechanically, washed, and inspected. Circulators and...

  14. Superluminal subway: The Krasnikov tube

    NASA Astrophysics Data System (ADS)

    Everett, Allen E.; Roman, Thomas A.

    1997-08-01

    The ``warp drive'' metric recently presented by Alcubierre has the problem that an observer at the center of the warp bubble is causally separated from the outer edge of the bubble wall. Hence such an observer can neither create a warp bubble on demand nor control one once it has been created. In addition, such a bubble requires negative energy densities. One might hope that elimination of the first problem might ameliorate the second as well. We analyze and generalize a metric, originally proposed by Krasnikov for two spacetime dimensions, which does not suffer from the first difficulty. As a consequence, the Krasnikov metric has the interesting property that, although the time for a one-way trip to a distant star cannot be shortened, the time for a round trip, as measured by clocks on Earth, can be made arbitrarily short. In our four-dimensional extension of this metric, a ``tube'' is constructed along the path of an outbound spaceship, which connects the Earth and the star. Inside the tube spacetime is flat, but the light cones are opened out so as to allow superluminal travel in one direction. We show that, although a single Krasnikov tube does not involve closed timelike curves, a time machine can be constructed with a system of two nonoverlapping tubes. Furthermore, it is demonstrated that Krasnikov tubes, like warp bubbles and traversable wormholes, also involve unphysically thin layers of negative energy density, as well as large total negative energies, and, therefore, probably cannot be realized in practice.

  15. Inspecting coiled tubing for well operations

    SciTech Connect

    Gard, M.F.; Pasternack, E.S.; Smith, L.J.

    1992-02-18

    This patent describes improvement in a coiled tubing system for insertion of a substantially continuous bendable length of metal tubing into and withdrawal from a wellbore, the system including a tubing injection unit disposed for injecting the length of tubing into the well bore and storage means for dispensing the length of tubing and receiving the length of tubing from the injection unit. The improvement includes: tubing inspection apparatus for substantially continuously inspecting the wall section of the tubing to detect cracks and structural defects which may lead to tubing failure, the apparatus comprising: a source of electromagnetic radiation mounted in proximity to the tubing between the injection unit and a wellhead into which the tubing is injected; a radiation detector unit for receiving signals from the source which have been projected through the wall of the tubing; means for receiving signals form the detector unit for monitoring the structural integrity o the wall of the tubing during one of injecting and withdrawing the tubing with respect to the wellhead; and housing means supported for rotation about a longitudinal axis of the tubing.

  16. The respiratory system of the piezophile Photobacterium profundum SS9 grown under various pressures.

    PubMed

    Tamegai, Hideyuki; Nishikawa, Shun; Haga, Minami; Bartlett, Douglas H

    2012-01-01

    It is known that the facultative piezophile Shewanella violacea DSS12 alters its respiratory components under the influence of hydrostatic pressure during growth. This can be considered one of the mechanisms of bacterial adaptation to high pressure. In this study, we investigated the respiratory system of another well-studied piezophile, Photobacterium profundum SS9. We analyzed cytochrome contents, the expression of genes encoding respiratory components in P. profundum SS9 grown under various conditions, and the pressure dependency of the terminal oxidase activities. Activity was more tolerant of relatively high pressures, such as 125 MPa when the cells were grown under high pressure as compared with cells grown under atmospheric pressure. Such properties observed are similar to the case of S. violacea. However, the contents of the cytochromes and expression of the respiratory genes were not influenced by growth pressure in P. profundum SS9, inconsistent with the case of S. violacea. We suggest that the mechanism of the piezoadaptation of the respiratory system of P. profundum SS9 differs from that of S. violacea, as described above, and that each strain chooses its own strategy. PMID:22878211

  17. Study of advanced communications satellite systems based on SS-FDMA

    NASA Technical Reports Server (NTRS)

    Kiesling, J.

    1980-01-01

    A satellite communication system based on the use of a multiple, contiguous beam satellite antenna and frequency division multiple access (FDMA) is studied. Emphasis is on the evaluation of the feasibility of SS (satellite switching) FDMA technology, particularly the multiple, contiguous beam antenna, the onboard switch and channelization, and on methods to overcome the effects of severe Ka band fading caused by precipitation. This technology is evaluated and plans for technology development and evaluation are given. The application of SS-FDMA to domestic satellite communications is also evaluated. Due to the potentially low cost Earth stations, SS-FDMA is particularly attractive for thin route applications up to several hundred kilobits per second, and offers the potential for competing with terrestrial facilities at low data rates and over short routes. The onboard switch also provides added route flexibility for heavy route systems. The key beneficial SS-FDMA strategy is to simplify and thus reduce the cost of the direct access Earth station at the expense of increased satellite complexity.

  18. Screening and Identification of ssDNA Aptamer for Human GP73

    PubMed Central

    Du, Jingchun; Hong, Jianming; Xu, Chun; Cai, Yuanyuan; Xiang, Bo; Zhou, Chengbo; Xu, Xia

    2015-01-01

    As one tumor marker of HCC, Golgi Protein 73 (GP73) is given more promise in the early diagnosis of HCC, and aptamers have been developed to compete with antibodies as biorecognition probes in different detection system. In this study, we utilized GP73 to screen specific ssDNA aptamers by SELEX technique. First, GP73 proteins were expressed and purified by prokaryotic expression system and Nickle ion affinity chromatography, respectively. At the same time, the immunogenicity of purified GP73 was confirmed by Western blotting. The enriched ssDNA library with high binding capacity for GP73 was obtained after ten rounds of SELEX. Then, thirty ssDNA aptamers were sequenced, in which two ssDNA aptamers with identical DNA sequence were confirmed, based on the alignment results, and designated as A10-2. Furthermore, the specific antibody could block the binding of A10-2 to GP73, and the specific binding of A10-2 to GP73 was also supported by the observation that several tumor cell lines exhibited variable expression level of GP73. Significantly, the identified aptamer A10-2 could distinguish normal and cancerous liver tissues. So, our results indicate that the aptamer A10-2 might be developed into one molecular probe to detect HCC from normal liver specimens. PMID:26583119

  19. New chimeric advanced Drug Delivery nano Systems (chi-aDDnSs) as doxorubicin carriers.

    PubMed

    Gardikis, Konstantinos; Tsimplouli, Chrisiida; Dimas, Konstantinos; Micha-Screttas, Maria; Demetzos, Costas

    2010-12-15

    Since the late 1960s, the field of drug delivery has focused on the creation of new formulations with improved properties, taking much attention to drug release from the carrier. Liposomes and dendrimers represent two of the most studied drug carriers. A Modulatory Liposomal Controlled Release System (MLCRS) combining liposomal and dendrimeric technology has been recently published as well as Liposomal locked-in Dendrimers (LLDs) technology which was considered to be a class of MLCRSs. Chimeric advanced Drug Delivery nano Systems (chi-aDDnSs) can be defined as mixed nanosystems due to the combination of the bionanomaterials used and can offer advantages as drug carriers. This work deals with the production of two new chi-aDDnSs incorporating the newly synthesized dendrimer PG1. One of the two formulations bears the exact lipidic composition as the commercial liposomal drug "Myocet". Doxorubicin (Dox) was incorporated into conventional (free of dendrimer) liposomal formulations and into the corresponding chi-aDDnSs, and the physicochemical characteristics, the in vitro drug release and the in vitro cytotoxicity against human cancer cell lines were assessed. The results revealed a different modulation release effect of doxorubicin from the chi-aDDnS, compared to the Myocet replica. Pharmacological cytotoxicity concerning all the chi-aDDnSs was very close to that of the conventional liposomal systems. PMID:20934501

  20. Development of a genetic system for a model manganese-oxidizing proteobacterium, Leptothrix discophora SS1.

    PubMed

    Bocioaga, Daniela; El Gheriany, Iman A; Lion, Leonard W; Ghiorse, William C; Shuler, Michael L; Hay, Anthony G

    2014-11-01

    Understanding the molecular underpinnings of manganese oxidation in Leptothrix discophora SS1 has been hampered by the lack of a genetic system. In this report, we describe the development of a genetic system for L. discophora SS1. The antibiotic sensitivity was characterized, and a procedure for transformation with exogenous DNA via conjugation was developed and optimized, resulting in a maximum transfer frequency of 5.2×10(-1) and a typical transfer frequency of the order of 1×10(-3) transconjugants per donor. Genetic manipulation of L. discophora SS1 was demonstrated by disrupting pyrF via chromosomal integration with a plasmid containing a R6Kγ origin of replication through homologous recombination. This resulted in resistance to 5-fluoroorotidine, which was abolished by complementation with an ectopically expressed copy of pyrF cloned into pBBR1MCS. This system is expected to be amenable to a systematic genetic analysis of L. discophora SS1, including those genes responsible for manganese oxidation. PMID:25149187

  1. Regulatory mechanisms of exoribonuclease PNPase and regulatory small RNA on T3SS of dickeya dadantii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The type III secretion system (T3SS) is an essential virulence factor for many bacterial pathogens. Polynucleotide phosphorylase (PNPase) is one of the major exoribonucleases in bacteria and plays important roles in mRNA degradation, tRNA processing, and small RNA (sRNA) turnover. In this study, we ...

  2. Structure and Long-Term Stability of Alkylphosphonic Acid Monolayers on SS316L Stainless Steel.

    PubMed

    Kosian, Medea; Smulders, Maarten M J; Zuilhof, Han

    2016-02-01

    Surface modification of stainless steel (SS316L) to improve surface properties or durability is an important avenue of research, as SS316L is widely used in industry and science. We studied, therefore, the formation and stability of a series of organic monolayers on SS316L under industrially relevant conditions. These included acidic (pH 3), basic (pH 11), neutral (Milli-Q water), and physiological conditions [10 mM phosphate-buffered saline (PBS)], as well as dry heating (120 °C). SS316L was modified with alkylphosphonic acids of chain length (CH2)n with n varying between 3 and 18. While alkylphosphonic acids of all chain lengths formed self-assembled monolayers with hydrophobic properties, only monolayers of chain lengths 12-18 formed ordered monolayers, as evidenced by static water contact angle (SCA), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and infrared reflection absorption spectroscopy (IRRAS). A long-term stability study revealed the excellent stability of monolayers with chain lengths 12-18 for up to 30 days in acid, neutral, and physiological solutions, and for up to 7 days under dry heating. Under strong basic conditions a partial breakdown of the monolayer was observed, especially for the shorter chain lengths. Finally, the effect of multivalent surface attachment on monolayer stability was explored by means of a series of divalent bisphosphonic acids. PMID:26771302

  3. Protective Effects of Antioxidant Peptide SS-31 Against Multiple Organ Dysfunctions During Endotoxemia.

    PubMed

    Li, Guoming; Wu, Jing; Li, Renqi; Yuan, Dong; Fan, Yunxia; Yang, Jianjun; Ji, Muhuo; Zhu, Sihai

    2016-02-01

    Oxidative stress causes mitochondrial impairment, the failure of energy production, and consequent organ dysfunctions. The aim of the present study was to investigate the potential therapeutic effects of mitochondrial antioxidant SS-31 on sepsis-induced organ dysfunctions and to explore the possible mechanism. Sepsis was induced by cecal ligation and puncture. Immediately and at 5 h after the operation, SS-31 (5 mg/kg) or vehicle was administered intraperitoneally. The levels of organ dysfunctions, malondialdehyde, superoxide dismutase, proinflammatory cytokines, pulmonary wet-to-dry weight ratio, myeloperoxidase activity, histological scores, nuclear factor kappa B p65, inducible nitric oxide synthase, reactive oxygen species, adenosine triphosphate, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells were assessed at the indicated time points. The 7-day survival rate was estimated by the Kaplan-Meier method. In the present study, SS-31 treatment significantly improved sepsis-induced organ dysfunctions as evidenced by decreased histological scores, increased arterial partial oxygen tension, and deceased serum alanine aminotransferase, urea nitrogen, and creatinine levels, which was accompanied by decreased levels of malondialdehyde, tumor necrosis factor-alpha, pulmonary myeloperoxidase activity, nuclear factor kappa B p65, inducible nitric oxide synthase, reactive oxygen species, and TUNEL-positive cells. In conclusion, our data suggested that the protective effects of SS-31 on sepsis-induced organ dysfunctions were associated with the inhibition of proinflammatory cytokines, oxidative stress, and apoptosis. PMID:26231114

  4. Analysis of T4SS-induced signaling by H. pylori using quantitative phosphoproteomics

    PubMed Central

    Glowinski, Frithjof; Holland, Carsten; Thiede, Bernd; Jungblut, Peter R.; Meyer, Thomas F.

    2014-01-01

    Helicobacter pylori is a Gram-negative bacterial pathogen colonizing the human stomach. Infection with H. pylori causes chronic inflammation of the gastric mucosa and may lead to peptic ulceration and/or gastric cancer. A major virulence determinant of H. pylori is the type IV secretion system (T4SS), which is used to inject the virulence factor CagA into the host cell, triggering a wide range of cellular signaling events. Here, we used a phosphoproteomic approach to investigate tyrosine signaling in response to host-pathogen interaction, using stable isotope labeling in cell culture (SILAC) of AGS cells to obtain a differential picture between multiple infection conditions. Cells were infected with wild type H. pylori P12, a P12Δ CagA deletion mutant, and a P12Δ PAI deletion mutant to compare signaling changes over time and in the absence of CagA or the T4SS. Tryptic peptides were enriched for tyrosine (Tyr) phosphopeptides and analyzed by nano-LC-Orbitrap MS. In total, 85 different phosphosites were found to be regulated following infection. The majority of phosphosites identified were kinases of the MAPK family. CagA and the T4SS were found to be key regulators of Tyr phosphosites. Our findings indicate that CagA primarily induces activation of ERK1 and integrin-linked factors, whereas the T4SS primarily modulates JNK and p38 activation. PMID:25101063

  5. Ball Indentation Studies on the Effect of Nitrogen on the Tensile Properties of 316LN SS

    NASA Astrophysics Data System (ADS)

    Mathew, M. D.; Ganesh Kumar, J.; Ganesan, V.; Laha, K.

    2015-12-01

    Type 316L(N) stainless steel (SS) containing 0.02-0.03 wt% carbon and 0.06-0.08 wt% nitrogen is used as the major structural material for the components of fast reactors. Research is underway to improve the high-temperature mechanical properties of 316LN SS by increasing the nitrogen content in the steel above the level of 0.08 wt%. In this investigation, ball indentation (BI) technique was used to evaluate the effect of nitrogen content on the tensile properties of 316LN SS. BI tests were conducted on four different heats of 316LN SS containing 0.07, 0.11, 0.14 and 0.22 wt% nitrogen in the temperature range 300-923 K. The tensile properties such as yield strength and ultimate tensile strength increased with increase in nitrogen content at all the investigated temperatures. These results were consistent with the corresponding uniaxial tensile test results. These studies showed that BI technique can be used to optimize the chemical composition during alloy development by evaluating tensile properties with minimum volume of material.

  6. 47. Photograph of a line drawing. '304 S.S. NUTSCHE BOX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Photograph of a line drawing. '304 S.S. NUTSCHE BOX AND FILTER PROBES, BUILDING H.' Holston Defense Corporation. June 24, 1955; revised 1958, 1960, 1965, 1968, 1982. Delineator: G. Sahlin. Drawing # 7651-1008/262. - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  7. NARSTO EPA SS HOUSTON TEXAQS2000 HCHO H2O2 DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 HCHO H2O2 DATA Project Title:  NARSTO ... Instrument:  Fluorescence Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston TexAQS2000 HCHO H2O2Guide Houston Project Plan  (PDF) ...

  8. Usability of AcceSS for Web Site Accessibility. Research Report

    ERIC Educational Resources Information Center

    Hackett, Stephanie; Parmanto, Bambang

    2006-01-01

    The standard display of web pages is inadequate for users who are visually impaired. Most visually impaired people obtain information from a web page in a linear fashion via a screen reader, whereas sighted users can immediately obtain a bird's-eye view of a web page's organization and content by quickly scanning the page. AcceSS (which stands for…

  9. PU/SS EUTECTIC ASSESSMENT IN 9975 PACKAGINGS IN A STORAGE FACILITY DURING EXTENDED FIRE

    SciTech Connect

    Gupta, N.

    2012-03-26

    In a radioactive material (RAM) packaging, the formation of eutectic at the Pu/SS (plutonium/stainless steel) interface is a serious concern and must be avoided to prevent of leakage of fissile material to the environment. The eutectic temperature for the Pu/SS is rather low (410 C) and could seriously impact the structural integrity of the containment vessel under accident conditions involving fire. The 9975 packaging is used for long term storage of Pu bearing materials in the DOE complex where the Pu comes in contact with the stainless steel containment vessel. Due to the serious consequences of the containment breach at the eutectic site, the Pu/SS interface temperature is kept well below the eutectic formation temperature of 410 C. This paper discusses the thermal models and the results for the extended fire conditions (1500 F for 86 minutes) that exist in a long term storage facility and concludes that the 9975 packaging Pu/SS interface temperature is well below the eutectic temperature.

  10. Irradiation creep of 11Cr-0.5Mo-2W,V,Nb ferritic-martensitic, modified 316, and 15Cr-20Ni austenitic S.S. irradiated in FFTF to 103-206 dpa

    NASA Astrophysics Data System (ADS)

    Uehira, A.; Mizuta, S.; Ukai, S.; Puigh, R. J.

    2000-12-01

    The irradiation creep of 11Cr-0.5Mo-2W-0.2V-0.05Nb ferritic-martensitic (PNC-FMS), modified 316 (PNC316) and 15Cr-20Ni base austenitic S.S. were determined by the gas pressurized capsule irradiation test using MOTA in FFTF. The pressurized capsules and open tubes were irradiated at 678-943 K to a peak dose of 206 dpa. The irradiation creep coefficients were derived from the diametral change differences between the capsules and open tubes, accounting for the stress-induced swelling. The creep compliance B0 and creep-swelling coupling coefficient D for PNC-FMS were found to be 0.43-0.76×10-6 MPa-1 dpa-1 and 0.85-2.5×10-2 MPa-1 for volumetric swelling, respectively. For both PNC316 and 15Cr-20Ni base S.S. the irradiation creep properties were very similar. B0 and D range from 0.55 to -1.5×10-6 MPa-1 dpa-1 and from 1.2 to -2.8×10-3 MPa-1, respectively.

  11. SST and SS changes during Saemangeum seawall construction using Landsat TM and ETM imagery

    NASA Astrophysics Data System (ADS)

    Park, Jong-Hwa; Na, Sang-il

    2010-10-01

    Saemangeum, located on the southwest coast of the Korean peninsula, is a 40 100 ha ongoing "reclamation" project in South Korea, concomitance damming the estuaries of the Mangyong and Dongjin rivers, replacing vast tidal land and sea-shallows with land and a huge freshwater reservoir. In 1991, the South Korean government announced that a seawall (dyke) would be constructed to link two headlands just south of the South Korean industrial port city of Gunsan and Buan, 270 kilometers southwest of Seoul, to create 400 km2 of farmland and a freshwater reservoir. Started in 1991, the 33km long seawall was finally completed on April 2006. Chlorophyll-a concentration, Suspended solids (SS), Sea surface temperature (SST), and turbidity are four important water quality variables, among other environmental factors such as salinity and pH, for tidal land production in Saemangeum. Change detection of the SST and SS during Saemangeum seawall construction was carried out by using LANDSAT TM and ETM imagery data. The spatial and temporal distribution of SST and SS are estimated and mapped with various degrees of success in Saemangeum area. Here we assessed the potential of these data to derive water quality parameters in a reclaimed estuary environment. We found that the evolution of the estuary, coastline, delta, and change detection results derived from LANDSAT TM and ETM images recorded in 1989, 2001 and 2008, respectively. Due to the limitations of image acquisition and noise, many researchers have employed the image processing technique to improve satellite data in order to assess water quality. The interpolation approach is a useful tool for the analyses and assessment on SST and SS on the basis of available satellite imagery data. Ordinary kriging (OK) were used to improve the SST and SS images in the study area. Results indicate that sedimentary transport, SS, and SST in Saemangeum has significantly changed during the past 20 years, with a dramatic increase in the amount of

  12. Hobetron current regulating switch tube

    SciTech Connect

    True, R.B.; Hansen, R.J.; Deb, D.N.; Good, G.R.; Reass, W.A.

    1999-07-01

    This paper describes a novel high power electron tube that can hold off voltages up to hundreds of kilovolts, and switch hundreds of amps of current. They call the divide the Hobertron since it utilizes a hollow electron beam. Unlike magnetron injection gun (MIG) switch tubes, it does not require a magnet. Further, it uses nonintercepting control laments, and a dispenser cathode for long life and reliability. Finally, it features a double walled Faraday cage collector for high power dissipation capability. Current is very tightly controlled against changes in voltage across the switch (it is an almost perfect pentode), thus this tube is ideally suited for direct series switching applications. In the paper, various Hobertron designs, and the computer codes and methods used to create them, will be described.

  13. Seismic data acquisition through tubing

    SciTech Connect

    Buettner, H M; Jervis, M

    1999-07-01

    We have collected good quality crosswell seismic data through production tubing in active oil fields at realistic interwell distances (300 ft). The data were collected at the Aera Cymric field (1998) and at a Chevron site (1997); both located in the Central Valley of California. The Aera data were used to produce travel-time tomographic images of the interwell region. Both sites have similar geology, namely siliceous shale (diatomite) with moderate to highly attenuating reservoir rocks. In addition we confirmed modeling predictions that typical tubing attenuation losses are on the order of 12 dB. We expect that the use of stronger sources and tube wave suppression will allow for crosswell imaging at realistic distances even for low Q or high noise situations. We are searching for an industrial partner now for a data collection in the gas wells of the San Juan Basin or South Texas.

  14. Tubing and cable cutting tool

    NASA Technical Reports Server (NTRS)

    Mcsmith, D. D.; Richardson, J. I. (Inventor)

    1984-01-01

    A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

  15. Synthesis and Functionalization of Gold Nanoparticles Using Chemically Modified ssDNA

    NASA Astrophysics Data System (ADS)

    Calabrese, P. G.

    In the first part of this thesis, methods for functionalizing spherical gold nanoparticles with nucleic acid binding ligands (aptamers) that target the VEGF receptor complex were developed. In order to provide a multiplexed labeling strategy for imaging the VEGF receptor complex in electron microscopy, gold nanoparticles of distinct sizes were conjugated to modified ssDNA aptamers that target the VEGF-A cytokine, the VEGFR-2 RTK receptor and a membrane associated co-receptor, Nrp-1. The modified ssDNA gold nanoparticle conjugates were applied to a human lung carcinoma cell line (A549) which has been shown to express each of these proteins and used as a model system for VEGF signaling. Binding constants for the modified aptamers were also determined using a fluorescence polarization anisotropy assay to determine KD and KOFF for the aptamers with their respective proteins. In the latter part of this thesis, a modied ssDNA SELEX protocol was also developed in order to evolve imidazole modied ssDNA sequences that assemble gold nanoparticles from Au3+ precursor ions in aqueous solution. Active sequences bound to nanoparticles were partitioned from inactive sequences based on density via ultracentrifugation through a discontinuous sucrose gradient. Colloidal gold solutions produced by the evolved pool had a distinct absorbance spectra and produced nanoparticles with a narrower distribution of sizes compared to colloidal gold solutions produced by the starting randomized pool of imidazole modified ssDNA. Sequencing data from the evolved pool shows that conserved 5 and 6 nt motifs were shared amongst many of the isolates, which indicates that these motifs could serve as chelation sites for gold atoms or help stabilize colloidal gold solutions in a base specific manner.

  16. Summary of Tests to Determine Effectiveness of Gelatin Strike on SS{ampersand}C Dissolver Solutions

    SciTech Connect

    Murray, A.M.; Karraker, D.G.

    1998-05-01

    The solutions from the dissolution of sand, slag, and crucible (SS&C) material are sufficiently different from previous solutions processed via the F-Canyon Purex process that the effectiveness of individual process steps needed to be ascertained. In this study, the effectiveness of gelatin strike was tested under a variety of conditions. Specifically, several concentrations of silica, fluoride, nitric acid (HNO{sub 3}), boric acid (H{sub 3}BO{sub 3}), and aluminium nitrate nonahydrate (ANN) were studied. The disengagement times of surrogate and plant SS&C dissolver solutions from plant solvent also were measured. The results of the tests indicate that gelatin strike does not coagulate the silica at the low concentration of silica ({tilde 30} ppm) expected in the SS&C dissolver solutions because the silicon is complexed with fluoride ions (e.g., SiF{sub 6}{sup -2}). The silicon fluoride complex is expected to remain with the aqueous phase during solvent extraction. The disengagement times of the dissolver solutions from the plant solvent were not affected by the presence of low concentrations of silica and no third phase formation was observed in the disengagement phase with the low silica concentrations. Tests of surrogate SS&C dissolver solutions with higher concentration of silica (less than 150 ppm) did show that gelatin strike followed by centrifugation resulted in good phase disengagement of the surrogate SS{ampersand}C dissolver solution from the plant dissolver solution. At the higher silica concentrations, there is not sufficient fluoride to complex with the silica, and the silica must be entrained by the gelatin and removed from the dissolver solution prior to solvent extraction.

  17. Use of hazard assessments to achieve risk reduction in the USDOE Stockpile Stewardship (SS-21) Program

    SciTech Connect

    Fischer, S.R.; Konkel, H.; Bott, T.; Eisenhawer, S.W.; DeYoung, L.; Hockert, J.

    1995-07-01

    This paper summarizes the nuclear explosive hazard assessment activities performed to support US Department of Energy (DOE) Stockpile Stewardship Demonstration Project SS-21, better known as the ``Seamless Safety`` program. Past practice within the DOE Complex has dictated the use of a significant number of post-design/fabrication safety reviews to analyze the safety associated with operations on nuclear explosives and to answer safety questions. These practices have focused on reviewing-in or auditing-in safety vs incorporating safety in the design process. SS-21 was proposed by the DOE as an avenue to develop a program to ``integrate established, recognized, verifiable safety criteria into the process at the design stage rather than continuing the reliance on reviews, evaluations and audits.`` The entire Seamless Safety design and development process is verified by a concurrent hazard assessment (HA). The primary purpose of the SS-21 Demonstration Project HA was to demonstrate the feasibility of performing concurrent HAs as part of an engineering design and development effort and then to evaluate the use of the HA to provide an indication in the risk reduction or gain in safety achieved. To accomplish this objective, HAs were performed on both baseline (i.e., old) and new (i.e. SS-21) B61-0 Center Case Section disassembly processes. These HAs were used to support the identification and documentation of weapon- and process-specific hazards and safety-critical operating steps. Both HAs focused on identifying accidents that had the potential for worker injury, public health effects, facility damage, toxic gas release, and dispersal of radioactive materials. A comparison of the baseline and SS-21 process risks provided a semi-quantitative estimate of the risk reduction gained via the Seamless Safety process.

  18. First insights into the genetic diversity of Echinococcus granulosus sensu stricto (s.s.) in Serbia.

    PubMed

    Debeljak, Zoran; Boufana, Belgees; Interisano, Maria; Vidanovic, Dejan; Kulisic, Zoran; Casulli, Adriano

    2016-06-15

    Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu stricto (s.s.) is a cosmopolitan zoonotic infection which is endemic in Serbia where it is subject to mandatory reporting. However, information on the incidence of the disease in humans and prevalence of hydatid infection in livestock remains limited. We used sequenced data of the cytochrome c oxidase subunit 1 (cox 1) mitochondrial gene to examine the genetic diversity and population structure of E. granulosus (s.s.) from intermediate hosts from Serbia. We also compared our generated nucleotide sequences with those reported for neighbouring European countries. Echinococcus canadensis was molecularly confirmed from pig and human hydatid isolates. E. granulosus (G1) was confirmed from sheep and cattle hydatid isolates as well as the first molecular confirmation in Serbia of E. granulosus G2 in sheep and E. granulosus G3 in sheep and cattle hydatid isolates. The Serbian E. granulosus (s.s.) parsimony network displayed 2 main haplotypes (SB02 and SB05) which together with the neutrality indices were suggestive of bottleneck and/or balancing selection. Haplotype analysis showed the presence of the common E. granulosus haplotype described from other worldwide regions. Investigation of the pairwise fixation (Fst) index suggested that Serbian populations of E. granulosus (s.s.) from sheep and cattle hosts showed moderate genetic differentiation. Six of the Serbian haplotypes (SB02-SB07) were shared with haplotypes from Bulgaria, Hungary and/or Romania. Further studies using a larger number of hydatid isolates from various locations across Serbia will provide more information on the genetic structure of E. granulosus (s.s.) within this region. PMID:27198778

  19. Fatigue Crack Propagation from Notched Specimens of 304 SS in elevated Temperature Aqueous Environment

    SciTech Connect

    Wire, G. L.; Mills, W. J.

    2002-08-01

    Fatigue crack propagation (FCP) rates for 304 stainless steel (304SS) were determined in 24 degree C and 288 degree C air and 288 degree C water using double-edged notch (DEN) specimens of 304 stainless steel (304 SS). Test performed at matched loading conditions in air and water at 288 degree C with 20-6- cc h[sub]2/kg h[sub]2O provided a direct comparison of the relative crack growth rates in air and water over a wide range of crack growth rates. The DEN crack extension ranged from short cracks (0.03-0.25 mm) to long cracks up to 4.06 mm, which are consistent with conventional deep crack tests. Crack growth rates of 304 SS in water were about 12 times the air rate. This 12X environmental enhancement persisted to crack extensions up to 4.06 mm, far outside the range associated with short crack effects. The large environmental degradation for 304 SS crack growth is consistent with the strong reduction of fatigue life in high hydrogen water. Further, very similar environmental effects w ere reported in fatigue crack growth tests in hydrogen water chemistry (HWC). Most literature data in high hydrogen water show only a mild environmental effect for 304 SS, of order 2.5 times air or less, but the tests were predominantly performed at high cyclic stress intensity or equivalently, high air rates. The environmental effect in low oxygen environments at low stress intensity depends strongly on both the stress ratio, R, and the load rise time, T[sub]r, as recently reported for austenitic stainless steel in BWR water. Fractography was performed for both tests in air and water. At 288 degree C in water, the fracture surfaces were crisply faceted with a crystallographic appearance, and showed striations under high magnification. The cleavage-like facets on the fracture surfaces suggest that hydrogen embrittlement is the primary cause of accelerated cracking.

  20. The pollen tube paradigm revisited.

    PubMed

    Kroeger, Jens; Geitmann, Anja

    2012-12-01

    The polar growth process characterizing pollen tube elongation has attracted numerous modeling attempts over the past years. While initial models focused on recreating the correct cellular geometry, recent models are increasingly based on experimentally assessed cellular parameters such as the dynamics of signaling processes and the mechanical properties of the cell wall. Recent modeling attempts have therefore substantially gained in biological relevance and predictive power. Different modeling methods are explained and the power and limitations of individual models are compared. Focus is on several recent models that use closed feedback loops in order to generate limit cycles representing the oscillatory behavior observed in growing tubes. PMID:23000432